<%BANNER%>

Magnetic Stratigraphy and Environmental Magnetism of Oceanic Sediments

xml version 1.0 encoding UTF-8
REPORT xmlns http:www.fcla.edudlsmddaitss xmlns:xsi http:www.w3.org2001XMLSchema-instance xsi:schemaLocation http:www.fcla.edudlsmddaitssdaitssReport.xsd
INGEST IEID E20101209_AAAAAO INGEST_TIME 2010-12-09T07:21:37Z PACKAGE UFE0017566_00001
AGREEMENT_INFO ACCOUNT UF PROJECT UFDC
FILES
FILE SIZE 5510 DFID F20101209_AAAKJH ORIGIN DEPOSITOR PATH evans_h_Page_060thm.jpg GLOBAL false PRESERVATION BIT MESSAGE_DIGEST ALGORITHM MD5
2520f45f5bd44b2d1e9f67631b93f273
SHA-1
7968344545ab6cfb0f98732462e708f51b7b0f32
36279 F20101209_AAAKIS evans_h_Page_049.QC.jpg
e715d624791d5cef9c6de4c981c4b3ff
ec3fedd85d4bc31659bb31502415c3f5e3ffe29e
930487 F20101209_AAAIZW evans_h_Page_035.jp2
7f2b9f47d5c13a0418a598ff009e1896
e204332e3d751465705de60608f64114ea6ba1ec
25271604 F20101209_AAAJGF evans_h_Page_010.tif
d248cf8829ad828f6d6b5289c24fbbd9
423cf976ebe5b22ff41d178647eadb5f231f7aff
146900 F20101209_AAAJFQ evans_h_Page_198.jp2
d16ac79f262cfc5cd6333571ece57b3c
91b76df9c78dcfaec6fd9171c22eff78fbccefa1
6817 F20101209_AAAKJI evans_h_Page_061thm.jpg
cd169aedb55f32ce070f6b90ef535291
6a6b235f994d139ba3c6f837d4ffe0b24e51e220
33393 F20101209_AAAKIT evans_h_Page_050.QC.jpg
8e4f157afddf703c65f557858055ffb2
4336d994c061288d4272362e0e363f1562a94ff5
489607 F20101209_AAAIZX evans_h_Page_036.jp2
eee0736a5e37a183bf4f1ddde242e09a
38928ee5eaf5b2833973c7fdeeef58ba84f5b23a
F20101209_AAAJGG evans_h_Page_011.tif
088538b69aa5583316478d3058bd457e
e117ca8b0c55d3bc6f9bd5aea3d43599749a91f9
139024 F20101209_AAAJFR evans_h_Page_199.jp2
6360dfd60e5968cfd329cc39474ac618
c531f1483265a305c87dffefc58c61005cfa76a4
25685 F20101209_AAAKJJ evans_h_Page_061.QC.jpg
a4667e7a2e2cc9a655646c8b662a0614
b58d98b814dea7902fbdb47e2a44feafa7c3db60
8877 F20101209_AAAKIU evans_h_Page_051thm.jpg
cffe949ed5de1addb0035a0ab419bed3
e89769afaf3f38bba525ed2ae1f5306fe78f73cd
948640 F20101209_AAAIZY evans_h_Page_037.jp2
309971862f03d9213fa92ea122a921d0
ba078261c3a69cea253830a8cc09b0683020ff4b
1053954 F20101209_AAAJGH evans_h_Page_012.tif
01cc2b08e35dbd8fa28b4fecc1b48662
ea021cb35a628e924126286d23fe6cde26a09a83
140248 F20101209_AAAJFS evans_h_Page_200.jp2
588f667b8b78bcc627385b4eb05bc651
6f8dd5ad6b6747a47b091e7d62c13b099a5bcab3
6922 F20101209_AAAKJK evans_h_Page_062thm.jpg
0d630387bf54b2b4697c03a6c4b5140b
0c7f9d48e3fb6961447a8bc95246f0858e3bd73b
8604 F20101209_AAAKIV evans_h_Page_052thm.jpg
d6d0c2531e3a8ef9c5953070609c9cd5
01c0b6e08f70a01d3b0ddc2cf9ffe2fabf1673c8
868213 F20101209_AAAIZZ evans_h_Page_038.jp2
25124f48ddfcac933153fde5310fb5a5
4a166af55e592de2930da150689378f0c34c9883
F20101209_AAAJGI evans_h_Page_013.tif
a562ad088269af5ad4eb6855419027c3
259a11bcacd3608bb170b0498a26a22524cbecb8
131506 F20101209_AAAJFT evans_h_Page_202.jp2
029b7c5057a1d946b4685047ccd778c9
50050c9818bf437e240932861f5d4c59a337e7d2
5072 F20101209_AAAKJL evans_h_Page_063thm.jpg
187c4bc21f38d9d440eed92f3a18e907
00e56363d63cc9e59cf064bcc9ba0c220f469787
35026 F20101209_AAAKIW evans_h_Page_052.QC.jpg
6466eb564ecba4994ab1823c80f5d7ab
dd76bfffa2ca084a78174ca758c3d891bc5ba4fd
F20101209_AAAJGJ evans_h_Page_014.tif
0de739361fcf79e51917e9ef65e50428
07d47be83b40da4868bf2439bc4f7159b2d3eaf7
41552 F20101209_AAAJFU evans_h_Page_203.jp2
82a072b6b92b61d74b674fdc0b25f452
508fd41acdaa62794045dffc4b94906358a22a82
9017 F20101209_AAAKKA evans_h_Page_075thm.jpg
56b35fc2ebc70582a263be05efd798a6
eae9ade7af8206ae5402f07445df09e228af2d4e
20172 F20101209_AAAKJM evans_h_Page_063.QC.jpg
71ce46309672a6580fd2dc65c5ea65f2
5532137a4f897dee5ab02375bf24f699bc9d00bb
9109 F20101209_AAAKIX evans_h_Page_053thm.jpg
e0fc6e07536eb4235ca533668852f128
26a2d16f5785de3271baa30c2aae3cbb93d30ecc
F20101209_AAAJGK evans_h_Page_015.tif
1dde4102ddc64dd919ba826468ed94a3
82f929e1e29f0028fe521052f1be8b721aead123
87496 F20101209_AAAJFV evans_h_Page_204.jp2
6ffcc7b385a1bc9a57e9478dba9171c0
5fae257a64c49d58c64696c5912197d1f0839620
9046 F20101209_AAAKKB evans_h_Page_076thm.jpg
31e4fa77083081d2d08a734e52eb9a1f
52bfefd9a22baa3655cacf0e2c5923bd42bed040
37596 F20101209_AAAKIY evans_h_Page_054.QC.jpg
c3647a733add195e477ae2ba299158d1
7cc11dbd34211b598c7c6dcf56b42c9a09e7e23d
F20101209_AAAJFW evans_h_Page_001.tif
d40c90a977f39ea612c44be8d0bc2e11
9b3593b538104e940ee81ae9970405369bd81067
38031 F20101209_AAAKKC evans_h_Page_076.QC.jpg
2536ad580bd9dceedd7132e07d4909e1
7017910ec621af6710b9d733f3867d32e47196e2
23286 F20101209_AAAKJN evans_h_Page_065.QC.jpg
fb34155ae264f67c46a4357ecdc3b6ec
4aff3287b6b8be348d9fa0a5d5e5cc3a8af556e0
8989 F20101209_AAAKIZ evans_h_Page_055thm.jpg
ccd27de4a7e540b8c3655ee899b9ad4d
931379c7babd2880eeb247759970f6b1266b8caa
F20101209_AAAJHA evans_h_Page_035.tif
758dd65603f287412f725748cb71b82c
13e5cb20ba72769367d31d62c6a7da8e05fdc598
F20101209_AAAJGL evans_h_Page_016.tif
b36bf00492483c4f25f9818721e902cd
421edb1e20e7f86d41135a3399d9896edf8d0755
F20101209_AAAJFX evans_h_Page_002.tif
d55b0385e3fd5c1bc5922edfdcaf14db
37b1c4f56cdca893b1fa44cc15bd7d08f8275145
8823 F20101209_AAAKKD evans_h_Page_077thm.jpg
72ebe584460094842d01b4c237c62c9e
e4ec72064709154f06cc1e6325af7e2d79fd106c
6486 F20101209_AAAKJO evans_h_Page_067thm.jpg
a5b7d1ba5a9a2c9af9a4b4f3d3d13674
cbdf7e9e10600c2d6160f3e56b66538a2089cf97
F20101209_AAAJHB evans_h_Page_036.tif
db4d681033eababed9c84d5c3e83a1ba
f462e1a196dad52f591142d56500bcadabe9ec27
F20101209_AAAJGM evans_h_Page_017.tif
ec127ac1051b86f845ac15232bf648b0
91898d550babc6f71f5fd6106ff808f5632eae5a
F20101209_AAAJFY evans_h_Page_003.tif
16eb865fa7917567050739c163e81887
567a1ac9931b89ca950e0bd308069d9bad470503
35861 F20101209_AAAKKE evans_h_Page_077.QC.jpg
64c4290c267ef79a679153b9cb72f542
0b43e1ebb4b7bd1630b5c5dfba7a1c5cadade72b
22233 F20101209_AAAKJP evans_h_Page_067.QC.jpg
abd085114b82f1df6e449c2919462129
de46b4477257d209fa23ecbb4b007949adf43916
F20101209_AAAJHC evans_h_Page_037.tif
5d594f8b46b751695e06b0a7fecc3ad3
a8a397561b6b6135e2d03cbf0f08a844d04798a1
F20101209_AAAJGN evans_h_Page_018.tif
56cfe53e54eb0802123aa5ef18aac614
eb8178d32c45360230c347ff360c14fa3a56e189
F20101209_AAAJFZ evans_h_Page_004.tif
bc95d1d0ba00bcd30d119a7a77245c5a
9ccab3e66ae1fd021532c8d47c30b46bf6812d20
32376 F20101209_AAAKKF evans_h_Page_078.QC.jpg
76a269e5f391966bf952c4bf73ace87b
0673d4647454f4f3572287efd2d8a93a27c6bb6a
4360 F20101209_AAAKJQ evans_h_Page_068thm.jpg
dc0cc2baa86b8d167283c7d97073f4c6
e0c1ac9027db6a71df4c878ab2d5983aa59b4f4c
F20101209_AAAJHD evans_h_Page_038.tif
5b1e9d64a9edb461407637389dee9ce9
35a252d062bc291407ca0a739115a12d9d484458
F20101209_AAAJGO evans_h_Page_019.tif
0879462f0a8d37d173a8dec4d67df5f4
a24587ae1ef0ef70038dc5c3cd0ff8d985d70bb5
8568 F20101209_AAAKKG evans_h_Page_079thm.jpg
6ac9e387f82aacd4bc497382cc6d952d
925b2f192763b2d2b01b003b83b97766b5d5fdc6
14151 F20101209_AAAKJR evans_h_Page_068.QC.jpg
742fd5a071e371db5c4380d246553653
2b1751d4fdd16e8f653a4abccd76e485a058453d
F20101209_AAAJHE evans_h_Page_039.tif
6d8e538776bcfea980f6e9ed9989e9e1
f60077d38a83d1132b2c600d521637ac1d1cce4c
F20101209_AAAJGP evans_h_Page_021.tif
447f3a0738b7e093b27150a0a21c4dc3
5f8bbf7e2ef7be1ffc2861676aeea57ef8c1e9de
35215 F20101209_AAAKKH evans_h_Page_079.QC.jpg
dd7f41677dccc4b7646388e3c9f62bf5
922b716f9bce2a98278b21e46757db3183c57fd0
12771 F20101209_AAAKJS evans_h_Page_069.QC.jpg
5fc85e5ad0aca0fc158be9ab57cdc4b0
71398e7dd553a8f26c54ab369dafff37da220bfe
F20101209_AAAJHF evans_h_Page_040.tif
3fdf2268870f5979786531a75c92edb2
db385bcd74e68857e657c603c7bec4d96b876f0c
F20101209_AAAJGQ evans_h_Page_024.tif
f0eda1129b2fc8fb5c2ac6009f38ce4e
aeedf4dc9e1b21fe64e95e14efe29a52bc4533e6
33596 F20101209_AAAKKI evans_h_Page_080.QC.jpg
6e1f26c1bf0c85087e760af6285bec42
91e4204837cea8976ae5604eddd080984c527cbb
32249 F20101209_AAAKJT evans_h_Page_070.QC.jpg
482aa2c7def115e590926946dc00266b
a91c831a3637dec563f8eb690f18b50b06623a07
F20101209_AAAJHG evans_h_Page_041.tif
2fb34877869dd3d9750bfa07b3af1811
16f7be98cac11710c973a031daab4b98012b9eb4
F20101209_AAAJGR evans_h_Page_026.tif
95a456363a2449300fef0ead33273d32
5b67f9b764a8841c23c8280d5a7898d35770eb93
8066 F20101209_AAAKKJ evans_h_Page_081thm.jpg
26e3dd1ff5e9046a842d8952817caf2d
7e466feba68b2a487eff442de2c9dd744eaf6406
7277 F20101209_AAAKJU evans_h_Page_071thm.jpg
aa94433864e50eaf18091d3c2b286108
fb433a261b9b376bf82490e032994492475dc8ef
F20101209_AAAJHH evans_h_Page_042.tif
d8fe7a21ba7a65ca4b94f1c567454017
91acc6badeadfc0fbbff429915c0c38b672ea787
F20101209_AAAJGS evans_h_Page_027.tif
b5d262e1744e0a14e52f800dcec57230
459234f4f4b0fac03be90912f3a9c27b3dd50e65
35134 F20101209_AAAKKK evans_h_Page_081.QC.jpg
baa1211c1c28579cb6332fe1c810ac02
25df90a74237448fcbae9374106a8582122087b6
26463 F20101209_AAAKJV evans_h_Page_071.QC.jpg
839263cb2862bec1becf85817757da54
83c02833b71002a88b3a8140a31fa34aac80ed59
F20101209_AAAJHI evans_h_Page_043.tif
85d50578a94e629e2164fab51457f889
8565e8bcb0671915715706bcbce11097b5ba20ac
F20101209_AAAJGT evans_h_Page_028.tif
b8955ebd5d282f947a1f3ab75089cff1
7767aa3c231e4de51feb900c4f2d2eddfd168ad7
9011 F20101209_AAAKKL evans_h_Page_083thm.jpg
8c63f3a78bf3690720df782d67991c3d
66b01fcd6c41e8f42bd021640dd03f217c646158
5391 F20101209_AAAKJW evans_h_Page_072thm.jpg
b275dce45be7a1ef7022baecf4a8b95a
365cf2207fe8c0f1bee98f6dd4b52f02e6410687
F20101209_AAAJHJ evans_h_Page_044.tif
7cb7bbf88d588c868d5ee88639c7bad9
28905f81a8d598315859050d59f07df191aa6ddf
F20101209_AAAJGU evans_h_Page_029.tif
56b91dde8dfccaccc095dfb0852904c3
1ac327b72db5737e03eb551b09944c151cfa2d6b
6408 F20101209_AAAKLA evans_h_Page_098thm.jpg
5db49d049736f6fbdb90d94d70bde9b4
3735ec36bc2c7261af013f70aa11c2aabf936022
36787 F20101209_AAAKKM evans_h_Page_083.QC.jpg
cf3f5945a5d440302d012c73169cdfd5
394ec98d161f74e4c741a3effafbb4fb1adb36af
6220 F20101209_AAAKJX evans_h_Page_073thm.jpg
8aee39732891ab84973a1b41cec860d4
569fabb3d8dae114b91d9c86664c00be58b873b7
F20101209_AAAJHK evans_h_Page_045.tif
1b4af6c0fdeb274d02390499c34477af
3b040847e47b6ac15f58e0839d9256ed7c936f7b
F20101209_AAAJGV evans_h_Page_030.tif
eead4c747fead4a88c2c0dfa9edfd3ed
d8cd0c210e18be668e24aef95828faa275c9d9dd
22824 F20101209_AAAKLB evans_h_Page_098.QC.jpg
53ed76c39919fe473c89ca714b71294d
76243d7acfe9b552d19c284caad375a0044a31b0
37653 F20101209_AAAKKN evans_h_Page_084.QC.jpg
46b6d6a6defe18ff072c712fb05120e3
b50df3dfdea6d8f738cbc5851e88a2cde3e35fcf
7262 F20101209_AAAKJY evans_h_Page_074thm.jpg
3c6944ea50e80a46cc5efe74977906fd
1bf43cab3f4a88c148e6618bd05abe6aff9845b1
F20101209_AAAJHL evans_h_Page_046.tif
1634a35de8042f57fe9ab0df7e2fa8f0
9efcc729c246c82fda8d1a61d463412049c91b06
F20101209_AAAJGW evans_h_Page_031.tif
57b8499e039efbe60c163401e03b2005
e64a12742ca7713f75245f5214813aa9f25e45bb
5755 F20101209_AAAKLC evans_h_Page_099thm.jpg
027d46adf1d94b89e39cb4deb54a08ab
301bb66c34fa12581d6129b72051d2ef65120abf
29638 F20101209_AAAKJZ evans_h_Page_074.QC.jpg
6445f5bfaf080fd0853ea315062f55d4
7f49b02bb721e17383d2ea2ffbe66c28613c73a7
F20101209_AAAJGX evans_h_Page_032.tif
ac07a9356a64167d35717a1694c82787
97e097a3951b1b817333f1eaddea7211b41a1fc8
F20101209_AAAJIA evans_h_Page_066.tif
8613526395cb05497f206d28b34a855c
787ffb1b9f17c3b1de86b98f6b296234f31716c1
20052 F20101209_AAAKLD evans_h_Page_099.QC.jpg
94b3b1f9cb0f25800e31a7f7a625d502
506f29d9091e428d9279408e83c24cbf8485a8fc
8703 F20101209_AAAKKO evans_h_Page_086thm.jpg
3efeca9056c68c31d2883568772521fe
8cdf452cbf80ce5ac9139a6261ccb0ecaf327395
F20101209_AAAJHM evans_h_Page_047.tif
a6a0bc50058da4a4d7624be614f3694d
3a10463a708db41648f4d76c3c8db254d291c615
F20101209_AAAJGY evans_h_Page_033.tif
48a76c9f9c513af43826ec28fafee906
1b1529fdf5abaf7e8ea6e3a128544bea29e76301
F20101209_AAAJIB evans_h_Page_068.tif
582da79f9525e7d7c581ccb7eaa6be78
6224009b1e33ec0764b6a98bcf69b91cf4c735cc
7635 F20101209_AAAKLE evans_h_Page_101thm.jpg
230e674185e8074da688c98c0ddc4a84
509526f18e5bd7c74eac273dbc720305d445cd3b
38479 F20101209_AAAKKP evans_h_Page_087.QC.jpg
0e18116ada731e68e2d9f78884681053
b44c9260f00e12f52420f2acd9148c29fd96d8fe
F20101209_AAAJHN evans_h_Page_048.tif
1f77eee2a07d7adf53de92bc8ce01e67
b119cbd064952b413d16cfcf56a15d61f0501291
F20101209_AAAJGZ evans_h_Page_034.tif
8a27a840c6663372d2d09009e7872399
472571e878b286db4bb074d988880921be97c079
F20101209_AAAJIC evans_h_Page_069.tif
ce8233c038c7c8129f1b9dae1f87a44f
df2bd7084144a5443c9491e09e68ce17ae2b18d2
27809 F20101209_AAAKLF evans_h_Page_101.QC.jpg
b5da521ea3bccba2167961b608e05881
8256968e0340254bbc232736bc1343a951798817
1769 F20101209_AAAKKQ evans_h_Page_089thm.jpg
7c1b0eea88d0f5b849a0b67e6009a34f
540623ed36570d3c25e7c07a7a087239b7a3434b
F20101209_AAAJHO evans_h_Page_049.tif
7c25b69a076f4b843f8fcf5eeb666e43
69f97bfa26430867cb3217929ee98c8796a6ca75
F20101209_AAAJID evans_h_Page_070.tif
8505446fb46dc1fa0a064666784bdc5e
ad31d4c01bc9a466680fd93341455b8fbc61cc9d
24055 F20101209_AAAKLG evans_h_Page_102.QC.jpg
db8c6b801475f499670cdd8dc3c4da43
08cf5e8aff511daaee2749031e010453725624fe
4439 F20101209_AAAKKR evans_h_Page_090thm.jpg
d449233736141ae7c11ccb7c4ea859e4
135a9fad8fea120eec05a7c5ff83d9a5458c47d5
F20101209_AAAJHP evans_h_Page_050.tif
4d27f272d751dcb56081dfff735a079e
2e718c337cc7e8631e5e3725d8ae01ca2c605706
F20101209_AAAJIE evans_h_Page_071.tif
421f67ecb909788831a3a7305deb0426
1dd11e0e4e5bce25be8acdd723b9fcb94ae49e2d
5373 F20101209_AAAKLH evans_h_Page_103thm.jpg
c0926a25d146cb6984d036f9aff9786e
5c5109b6939a0a26ce806c5afbd4ba432bfa1231
18510 F20101209_AAAKKS evans_h_Page_090.QC.jpg
653f51c3dadd45a6f61659c56e77264a
c574f851e22caab942df189bd4f2fcaa60556a78
F20101209_AAAJHQ evans_h_Page_051.tif
36e377d44817d5ea981006d935cdfff3
671573454643a294a5804a9377a8d118d714addd
F20101209_AAAJIF evans_h_Page_072.tif
3820df8a11160c4913606bab812b795d
7963a93e21e0f637e9bb4aba60087dbf429f9457
2726 F20101209_AAAKLI evans_h_Page_104thm.jpg
f20d2eadaa197da9be6e74357c6bd99c
381864b739a915c5c49f83402c910868c7ddd78b
3715 F20101209_AAAKKT evans_h_Page_091thm.jpg
0f77cf7a3d786396b3b71362a3bbb7c1
3d0a77cdd06675202298f8af441087eb76e4bcb8
F20101209_AAAJHR evans_h_Page_053.tif
40cf3fa234d7a5be8296f3833824c626
ac73cf7d02f7ea1e6c84e34a54382f2d850d2251
F20101209_AAAJIG evans_h_Page_073.tif
791ff4a3e804a037434fbd91e9d3b0de
400da503ca630cf7fc9987e36f95af42c8db43ca
37141 F20101209_AAAKLJ evans_h_Page_105.QC.jpg
c18d55491d993bc9da983606e90caa7c
3374f48e780cbeba34c5114c1f8466bfe92c9eb7
5407 F20101209_AAAKKU evans_h_Page_092thm.jpg
6a30688cdf1d140b4639e8d17ddaa19d
8ac6902479d9383cfaf962ce41358d6b0becc901
F20101209_AAAJHS evans_h_Page_056.tif
586e46d99481021e5a86e9fa13c46756
82d879fb86ea25f3c3cb06d1d24e4ef1e2a8594b
F20101209_AAAJIH evans_h_Page_074.tif
6715539a7353aef3483e00de02d76625
7338443f8d9420baf2add1bc92ce1050778b4365
9254 F20101209_AAAKLK evans_h_Page_106thm.jpg
c78587818c318ee8162442a3925fda93
a84550d5c49580a12a1a7a12812fd7b0996c9631
27457 F20101209_AAAKKV evans_h_Page_093.QC.jpg
57e0bb0f8c998707c4946c6c45482115
8d95c5385382d86ca95e490ed92880d1128432b3
F20101209_AAAJHT evans_h_Page_057.tif
309b4c539acf6dfffb669de3d28ae7c0
46e72ab11937a71744ce165fd816af44b5749a8b
F20101209_AAAJII evans_h_Page_075.tif
a1c1591c49e4e349df8db8ee7cefa441
bb962769069418021cb1373edf570a1acd0c6297
8728 F20101209_AAAKLL evans_h_Page_107thm.jpg
2c2b62125822f6d6a4115575ddc86984
f552b518708f3dfc5aba16d31b9d3154f6202cbf
7012 F20101209_AAAKKW evans_h_Page_094thm.jpg
f05abb2862fd38efa92687375c39e56c
0d88989fdf3caa4b7d7ef374c0572daeeea6f6f0
F20101209_AAAJHU evans_h_Page_058.tif
e2204fd8c178ac95333ff83aa314d9b2
563ed1b1b5958e2d9fefecdc8b7e2f9348b422b7
F20101209_AAAJIJ evans_h_Page_076.tif
25e9527a048fc39e2bac5723abe087f8
556cfbb4e2e66d86c5abae57eb72d2d82709fbdb
14055 F20101209_AAAKMA evans_h_Page_123.QC.jpg
7073baa1cc9ca45037484276e1e72319
9d5d334f8271bcf31a57445486150b82323dc322
37180 F20101209_AAAKLM evans_h_Page_108.QC.jpg
f873459e84959dc421e1e6d96d078d46
15e8f00ed58561d23dc9587c93d20b1d92c09223
7253 F20101209_AAAKKX evans_h_Page_095thm.jpg
60545ac7076fdcf0d85dea1f01433687
e30c3e311e9548c0c7ea6031b253a10884a2bf83
F20101209_AAAJHV evans_h_Page_060.tif
c1f2732027f8e3d33198f5cce384d911
635ba11bf45a6d025b144209f87dbfef2f38ab33
F20101209_AAAJIK evans_h_Page_077.tif
483b50710ed41b55d4449d318c2fe883
b0e1524865061c0865825674046d5390b3423510
5886 F20101209_AAAKMB evans_h_Page_124thm.jpg
6b21792b1fe728acdb55ca0b8015fb9c
dd10a8b9549d490ae0026b902acb1324bed5b52e
35843 F20101209_AAAKLN evans_h_Page_110.QC.jpg
ab01efd0d90dc8710b7066f849255f40
595aa7f6df7d09d24e96eb8dc081fd0eb5befeea
26907 F20101209_AAAKKY evans_h_Page_095.QC.jpg
c939ca8719c4137744ec4a01c2524242
edc139ceeee16edab9dd9b58213bec81441b9264
F20101209_AAAJHW evans_h_Page_061.tif
faf0b183baf82a0631615254a4f11854
d92701031f4f73f0e7f0e972b44455f2fc7fb546
F20101209_AAAJIL evans_h_Page_079.tif
a5defdd5130ab86ab4410ce9df77a612
fdb7f8fca4b248746385ed72e1ca02fc301305b1
21331 F20101209_AAAKMC evans_h_Page_124.QC.jpg
c22b594a37d8bb7f8e1d8c0eff5259da
890aaf8717b4313b86e94b6a3e65c72c11415dfb
36167 F20101209_AAAKLO evans_h_Page_112.QC.jpg
5a902f46db64775fe2cf8f1d89136ee4
cc56b236e6ce750cb72d94583770d22d4111ddd4
7327 F20101209_AAAKKZ evans_h_Page_096thm.jpg
a149271cc7275c9432e36ac236b3ce63
bbddb629a541a9d8f91393782b43205c7cfef6c7
F20101209_AAAJHX evans_h_Page_063.tif
2489fb4535f3681fc6a31a754862fec1
ea11fb62ea577eb5786f8758bd40da4c873538fd
F20101209_AAAJJA evans_h_Page_094.tif
3d731a1091a0920692c1df1e946bc364
a7e97d86c80d7e4706125f1a3ebb1a32fedb7ec0
F20101209_AAAJIM evans_h_Page_080.tif
50de3815d6769ef4a2aab4aa93161ffd
86de634b1f9a0e26b64fcf24225e4fb0d0bf5ca1
2990 F20101209_AAAKMD evans_h_Page_125thm.jpg
015fd43b2882174c74586ba627cbc330
bd85e9cfa1402bf9c088d5334a870d39acba5e4b
F20101209_AAAJJB evans_h_Page_095.tif
6a68062e6b502b7e55d44ef6a6a0090f
2055be37247ace79f4f6426ed1af92069fe5edf2
F20101209_AAAJHY evans_h_Page_064.tif
b7806a6b6f735e7cdb4e7eaa01ecc935
4e28614d8ddd428bbddc8878b15ceab64c0da2c6
10431 F20101209_AAAKME evans_h_Page_125.QC.jpg
80f0008b23b7a20fcb0b201f1e9f8cb2
1ec198ac1749a7e929dcf666313026481746dac2
8797 F20101209_AAAKLP evans_h_Page_113thm.jpg
efbc4d3c7c5c32853800723bc0bf9843
aa7b9bb45844abe0914a24fbb2f162cca5962b83
F20101209_AAAJJC evans_h_Page_096.tif
d647483fde68d865e65f4238cb0807c1
b8fb4541251b5f1512f93eb5c45d0e6dca286fae
F20101209_AAAJIN evans_h_Page_081.tif
ee865609cf1e0df0128c949c9516b2d8
d212f392cdf7ddf241f7e9035a637dd67e15c5a9
F20101209_AAAJHZ evans_h_Page_065.tif
5ba7cc59df24b78a248e996ef474ab1c
60032d0f29112e4f3da0dea4f5a183e8ebc4ca25
4850 F20101209_AAAKMF evans_h_Page_126thm.jpg
632c9b4988b5b3db0291549c770fcfaf
b1e2aee8d7285161bc28b2714809f6c7b11c3fab
36479 F20101209_AAAKLQ evans_h_Page_113.QC.jpg
b814d5e4b27aa5d84c3566e9f7330b28
7d515230114554bdefe43bdcb70465c397da4a45
F20101209_AAAJJD evans_h_Page_098.tif
24f8d995dd8be98ceb65c61d38d92258
85a7318eef03f80fdac1ff0d5ed209065d84ef05
F20101209_AAAJIO evans_h_Page_082.tif
daf31f0d484227b0421528c27569cefe
2defe67a6b7f56d4812b72a5fa93eb8cc3fe7d30
16518 F20101209_AAAKMG evans_h_Page_126.QC.jpg
6181fa750289a9449e0f57f6c1a77ca2
1dcea5be49ea85cb1b5cf2a73044d84905128de6
9086 F20101209_AAAKLR evans_h_Page_114thm.jpg
7fa592230ed7b03fb127c64e0a0927e7
dd42a34a95cfd46d63c196d707e8a6cdb87e9a0d
F20101209_AAAJJE evans_h_Page_099.tif
05d9cad164fb3c41104efcbbe75e0d87
8ceb31795b58d1c460d0c4649ec55f6081ac851c
F20101209_AAAJIP evans_h_Page_083.tif
b07625d57a88d058653ebdba5c8a9253
4ef755dcb1ed0fc1a9f9cedf25caec638c895894
7249 F20101209_AAAKMH evans_h_Page_127thm.jpg
d00113bf22d616ab951e9b39f84748d7
9a12b8f609bbfe31be67d5df887995d858686a06
9096 F20101209_AAAKLS evans_h_Page_115thm.jpg
1b47e852fa9fbbb34711d74c463b51c7
30c509b9b5bf99720fbbfa785cc67e4748f48dfb
F20101209_AAAJJF evans_h_Page_100.tif
18cb98c8257dd4599110d61776a11c01
d44b5b60d87c5231707b605cd3b55e52b3d60a16
F20101209_AAAJIQ evans_h_Page_084.tif
7dccd9888c14802b800a8ad9bb2bc704
fb0f67e9c9c42d2be90434c95f3daf5b2032fa60
26941 F20101209_AAAKMI evans_h_Page_127.QC.jpg
e851109c201e30ab3d991ca50533d3a3
ca990e98247bbb7309198b18fd784a93f98f227a
36231 F20101209_AAAKLT evans_h_Page_116.QC.jpg
c835cca1cb612be1b70e7d8658b1bd08
4cb7cba851cf4ae49569ae16720b035c6a203f79
F20101209_AAAJJG evans_h_Page_101.tif
73bb3c258cc1a3b2f3e00ad3d6dd37e3
de93caa0864446c38e4d9a8f829b661267c8e5a6
F20101209_AAAJIR evans_h_Page_085.tif
4838bf5fb6bc19c48c70d8524b044ffd
d1c59bf4b59cdcdc235a4c4600d80403000fa7d8
5404 F20101209_AAAKMJ evans_h_Page_128thm.jpg
3f84ed93c8e670633cd10a9f94e29767
c8f6d77c03715724e0ac968973094ef4e10dc139
9152 F20101209_AAAKLU evans_h_Page_117thm.jpg
76549399377347f444c41b68d140fea4
7bfdc55858e3e192fdd00421384582d67df2abd4
F20101209_AAAJJH evans_h_Page_102.tif
4e8fb0900d53a5e8f6a65318c84f4f40
91e912b2fa27c2745f17a6d9357c29664dd58c66
F20101209_AAAJIS evans_h_Page_086.tif
e365ebee2e8357d1ef546b7cdf7ec40b
75c0d0c0b2c6c6ee286f0907aa4819f383519c08
19380 F20101209_AAAKMK evans_h_Page_128.QC.jpg
ef3a68d270dbef95de70cb79b0e2bd09
ce2045475f6fc4e44bd31da18d2dceb32c1308d3
35065 F20101209_AAAKLV evans_h_Page_118.QC.jpg
3f2df073cf7d0c912ff3cd7c9f37f8fa
19ed5e41fd3f63af17449de7d13d800131089e18
F20101209_AAAJJI evans_h_Page_103.tif
b9805be4c872a60bce20f84f536bd2f0
cb6efdc12a1b96cb450d40a890661a79c3a9cdca
F20101209_AAAJIT evans_h_Page_087.tif
9dbe316033028c55d62e4d26a99edd88
667cc0f9152c429f449d0cd69debf82f3965f05d
4345 F20101209_AAAKML evans_h_Page_129thm.jpg
33af96b0d9ab5be1960c857113230867
93b1ee2e71ed4c62e9457c75430927f0b6d38ede
8089 F20101209_AAAKLW evans_h_Page_119thm.jpg
d2b3adf32364d92c2b01be30238f6bc1
f89da7d5083359263f1d489d755cd1ada6610ac6
F20101209_AAAJJJ evans_h_Page_104.tif
1d3842da79ac08dff71258f54c635ab5
fcb01752f3f4a6a08d6bbbfc225a9a18e1c53825
F20101209_AAAJIU evans_h_Page_088.tif
02b6d49ba494aa6ee54eb43352bc91f1
d724ea9667c0731dd419349989f6dc1956a056d2
34939 F20101209_AAAKNA evans_h_Page_140.QC.jpg
deed2edd05dc6255dc0bf81036ec610e
b3c43fd0b44e5d46f17e1aebda38de01dc6fc651
7248 F20101209_AAAKMM evans_h_Page_130thm.jpg
9fcbfd38c7c3de6eb17d6b43bf8e23db
10538e3981aebb0dc55200b204ad6a0b36f0cf98
34249 F20101209_AAAKLX evans_h_Page_119.QC.jpg
f8468e71b9c67304253ec71c93790ea7
c78f1ca544e02e5ebe0a3a2f25508be0d004344d
F20101209_AAAJJK evans_h_Page_107.tif
c60f291651084ead15f95785e0d9b06d
e8f6a59a6532d1a4d977aaffc8752444807223e8
F20101209_AAAJIV evans_h_Page_089.tif
e5884a1407f1385f7a54b3a671a0ce03
170b5149265a717e743e5dcf338857b371b7f7b7
8975 F20101209_AAAKNB evans_h_Page_142thm.jpg
ef56ef28c86c8558901071ef850f2d63
9c43e37034274d240f575d4c0556e5116b153e42
24516 F20101209_AAAKMN evans_h_Page_130.QC.jpg
46864713bcb35c4e8c12a01ebc8c8f20
3db8f9609d93544301f8376ae2cc02e08910aef3
4132 F20101209_AAAKLY evans_h_Page_120thm.jpg
90eb7854f1c92f04ffa7a4171ea7243e
9d0f10f73892a4dcf53d13ae2e89939ec33f79e6
F20101209_AAAJJL evans_h_Page_108.tif
2b4a0676f26ad40f8aa6c4c21caa5150
dd8d383754c8d3138b98d1b3728436e3b272fd06
F20101209_AAAJIW evans_h_Page_090.tif
ddb6142f758ac70e2306f39dae594382
c9c31488733983e04b62ed8baf5a04ec6cd687dc
37922 F20101209_AAAKNC evans_h_Page_142.QC.jpg
c2df1d477471341ffce87d1f9c273ed2
0855090fefefd617b0b190e321710d415fc300c8
7298 F20101209_AAAKMO evans_h_Page_131thm.jpg
1a1c2a010b7b3fe13286b4ffe14cd9e2
a29799c55cdbb922191eacc573f521f28ffab6c8
16267 F20101209_AAAKLZ evans_h_Page_120.QC.jpg
b312c0fb0b0bbf5904d8f071904e0a4d
15a8b9f0d1879dad7c074ebb74fdd4e6416b64f4
F20101209_AAAJJM evans_h_Page_109.tif
7f10b89623e620e70851dcbeb950a1df
83325b39ed7f03cd8aa8a06dbbf06a8cd069097d
F20101209_AAAJIX evans_h_Page_091.tif
793a94dc5265c8ba5c20252a82a67838
8051026a5913a1f0bbe7bac7b8933f001ab68e48
F20101209_AAAJKA evans_h_Page_124.tif
6d427ad86a5ce97e47d167ff809a867a
cfeacb9c72410fb9635558be0ca6bf897dc1d6b6
8783 F20101209_AAAKND evans_h_Page_143thm.jpg
07c697a0002d4c82b3beadc9cdab2f85
10d855bdf28c6c63d796a1fbd1f9c4ab628abba8
28534 F20101209_AAAKMP evans_h_Page_131.QC.jpg
b2931d660692e34d0ef35fa692fa3f4c
f0f319e886e525160081cbaf67ac8a8c8b4cc7ac
F20101209_AAAJJN evans_h_Page_110.tif
e1922b10f1b88147149e2499c2529186
4e0175e8b0ede4d06a6434b5c426587917d83f58
F20101209_AAAJIY evans_h_Page_092.tif
37c2f3c8c45626efd275f11d86679753
59b38951cf252c5e6f04412aebd383b5ecbb2e51
F20101209_AAAJKB evans_h_Page_125.tif
71d90bbcb0911852e14e4bd18d64476d
dff68be97fef551ee76f54275a34f46fe0f9ee01
36240 F20101209_AAAKNE evans_h_Page_143.QC.jpg
c4f8b20dded80f93736051f3acf0eabf
f9a08e2e9e2e98e38309f2e629043ba5a938a829
F20101209_AAAJIZ evans_h_Page_093.tif
b2aa8636174bbfc4186f7078ac16ac79
1c96aea1fc390d467422666fa88d01810d5df8ab
F20101209_AAAJKC evans_h_Page_126.tif
f048069b002f54a0a99f111500601487
de06323963f23bd6943b230e21237477c27ba7ff
9099 F20101209_AAAKNF evans_h_Page_144thm.jpg
884fac5bad7c7657a4bb693cdf3259ee
c0a4901bc2e1cf5d2e2bcf9e2f228805231c0af4
7457 F20101209_AAAKMQ evans_h_Page_132thm.jpg
69013087d4cb78224d66b6ae5da291f6
1365fb1016734322d7d30c86450a642bb7999752
F20101209_AAAJJO evans_h_Page_112.tif
1a7c8395476631c6e0094c68b97be826
a1ecaa1c689f6c008a96a1e826181ba13ff95f31
F20101209_AAAJKD evans_h_Page_127.tif
94a34f56b815b15fd59d7cdbca95c9b2
de45b12e3c87091ad1283c49ebb28c94feb0586e
36226 F20101209_AAAKNG evans_h_Page_144.QC.jpg
5ff774da0e73c0887f844a23f4bf3b31
d004d205f59eda10fa3c85abcb531f35ea80e130
28610 F20101209_AAAKMR evans_h_Page_132.QC.jpg
05cfb4b873f1386fa65a0909e32a8dcc
88b1f243db8c4d298cfa51cbda261cee0a51100b
F20101209_AAAJJP evans_h_Page_113.tif
2009e35060de80ffc04250d1d036a124
8c488c1ab58c0196e4196a2ac80313bb3c18d8de
F20101209_AAAJKE evans_h_Page_128.tif
03a1637d8dddfa6fbb4df0f6f5695f59
096d5b79afcca3910a7ea6349e4b59dc00a0fd13
1601 F20101209_AAAKNH evans_h_Page_145thm.jpg
634f43decbea60d46710c8a7ca2d2221
25fb4b8507a996d20f737d5fa0d6be2bc5a79fdf
6529 F20101209_AAAKMS evans_h_Page_133thm.jpg
92bea94f27e5322b6830c40f5470a09d
776949c39055a32d240075b36d841993aee2d0dd
F20101209_AAAJJQ evans_h_Page_114.tif
b0ef76d6eb5761e9ebb272cc2229c9f3
9bc71601b1716b9cffb54de4e46e7029f7a6ff13
F20101209_AAAJKF evans_h_Page_129.tif
7a754845e43a256a149297f2cc724b4d
7eb92bb3be7e2705725d6624b4b7a0ad5bd60019
3876 F20101209_AAAKNI evans_h_Page_146thm.jpg
27e758558544267b534ba91c6ff486b5
06a41d3d1771581a347e961dde2db688b03b1de6
23657 F20101209_AAAKMT evans_h_Page_133.QC.jpg
7f095b0c0b43780dec3ed98b21c1ba14
01e8f032a3eb64e616764976b4f86a8b9b0196e0
F20101209_AAAJJR evans_h_Page_115.tif
66c12a3742292f7f69be95f32003c07c
de2c2d2a36779f2e8343a93b902e6fc856ec0659
F20101209_AAAJKG evans_h_Page_130.tif
aef78de3efa7531a7edcc50b8d2d37da
9806f35f9a7b631af8d848f9a749d12b1fa7bfcc
21275 F20101209_AAAKNJ evans_h_Page_148.QC.jpg
221ea3c410c0621db839cb1894afb880
f15f8c43871b8bb2eebbd895ff30fc18feb8adbf
4199 F20101209_AAAKMU evans_h_Page_134thm.jpg
854b71e8ed9301ae3cf865e8a08fa88b
f379ef5be64b4d2573d9709099e532177ee401f5
F20101209_AAAJJS evans_h_Page_116.tif
ba35362bf01651c10c7963dd1c18565d
a28a957241928e14d2e6569448d9ecacaf6dbbf5
F20101209_AAAJKH evans_h_Page_131.tif
1f4c6d6e67fccae10afa28a8d5b515ac
c098624d33139c78b661fc5dfbe7cf5d5e5c633b
9264 F20101209_AAAKNK evans_h_Page_149thm.jpg
e6837dc26baef5c11e985e42473c1736
1c214db71e006479645b1710c61c2138aa3e8545
36871 F20101209_AAAKMV evans_h_Page_136.QC.jpg
1c0599af5d9067204a0d80d0ab7175f3
b19162284be2c2ece96d5d3ae005dc3ebe4c4376
F20101209_AAAJJT evans_h_Page_117.tif
8c50f1ca20c108d6bdb740dd5e8e965f
b2b27f47a65c2be097b345e2fc6c3939e089311b
F20101209_AAAJKI evans_h_Page_132.tif
c0f172a0689cdd23729806ad642ffea1
0003cbc5d36caf011762f7995a683b183e0e2920
35005 F20101209_AAAKNL evans_h_Page_149.QC.jpg
6749fe521c0e2d35c8b9beb061c3b327
449d39eb0755e9adfd783a9d025b474e5edaa241
8238 F20101209_AAAKMW evans_h_Page_137thm.jpg
d0cc81d76ab62775137ab36920f121e6
5fed5f4e267f48823c07fe9f4d83e21a8cad0948
F20101209_AAAJJU evans_h_Page_118.tif
1c982217f0bffa29f093d698f4ffd6b3
9ec5df8e81abca00e023f3e8c6db1919b5bade55
F20101209_AAAJKJ evans_h_Page_133.tif
0008e21c031b79751c09ecb31cc82f10
886c315af7293191e51608f087cbd1fea93c6048
8871 F20101209_AAAKOA evans_h_Page_162thm.jpg
0d098ee5b7351f9038bbcacaec371d1d
2d09f567283e9746a7a053be4e9d872203d162f5
8813 F20101209_AAAKNM evans_h_Page_150thm.jpg
fc2c9008d40bcc480f34d053bdd0110f
b0ff69a3bec500c508fed10c710c557578673f0a
34524 F20101209_AAAKMX evans_h_Page_137.QC.jpg
9f89c6cc5f5bb9ecb1646b1127b07342
ebc6ca5c1f89f51bdd007f8b1d03b7fa92b486ac
F20101209_AAAJJV evans_h_Page_119.tif
50f147cedd989a130a238459b1135e06
5e7b19ddea499bcf1de9fb2b6bbca378d532a07d
F20101209_AAAJKK evans_h_Page_134.tif
d31346fcac07f7b61c86898fefee09ed
bdc0eacf32e287f3ffffcf1d81cddfde5eff3fc7
8435 F20101209_AAAKOB evans_h_Page_164thm.jpg
c30d1b5c9f7a82b6012d64dd8af725da
a8ea0b6566ebcfd53c0d75162809b7b6c3a2a102
4351 F20101209_AAAKNN evans_h_Page_151thm.jpg
7d774348e150a23c477e5657100d9790
dd7b916a82fa3848548868f440748d1e114006d2
36513 F20101209_AAAKMY evans_h_Page_138.QC.jpg
fe859747f3e607d2d6a3fcf000e1ab12
165c2cbb65e3c74d13663d2b01c69cfd4b123ead
F20101209_AAAJJW evans_h_Page_120.tif
60182607a79e6a73a8966daf3782a8ef
1c074d4bc7fbdee1e309b87849a8d41ec884d98d
F20101209_AAAJKL evans_h_Page_135.tif
7e437b1bc33506291608a53069b946ef
52e105ab98d0547cc0a6706e002f9577905dcdc1
33004 F20101209_AAAKOC evans_h_Page_164.QC.jpg
d12f50abcc354cbcea70b9dd947717b1
803aca46dea0bdad97faf64201cc4ccdcf73b738
14705 F20101209_AAAKNO evans_h_Page_151.QC.jpg
279c480ffa1515b46861c08dffbba5cd
069063bf421b7ae12c405db7e45e176966909206
8777 F20101209_AAAKMZ evans_h_Page_140thm.jpg
68d207800409bb53cc6985e2da428473
c8791efc25f4cd7eef6d669b3c4190d73562c795
F20101209_AAAJJX evans_h_Page_121.tif
be3e0519d1f288bf0ebf9347b990ade3
7ff552fa998adc05b77cb92a3113a09a4d1ebe11
F20101209_AAAJLA evans_h_Page_151.tif
01d54f8eae1c89947cc69613d027ab6c
ffe7351f16670915e1ac3b2e11320aa339b811c1
F20101209_AAAJKM evans_h_Page_136.tif
45ea551d5b15261e605ede26d9365aad
de3d1ba14b1cbcea4b7f13dd1756f38188f63df0
20150 F20101209_AAAKOD evans_h_Page_165.QC.jpg
5837d66801aedc68be5079d5cfda822d
41dc06e4e091a86f70576f8fe3a14ddb1f449121
13154 F20101209_AAAKNP evans_h_Page_152.QC.jpg
6937bdf048d40f490d73ce6a59c0fbc0
132ae7ee06324d7827509d669cd8a71efa41e723
F20101209_AAAJJY evans_h_Page_122.tif
fbe4604594d8f61ba42ae85f57dda9e3
e77bbccdb4a11282f03b442c864cfbfeca104d3b
F20101209_AAAJLB evans_h_Page_152.tif
9cce0e890b63fc716cc944cb54d77f4e
f992b812d8ee7b46c7a0ea7b0c5e77393bfce01e
F20101209_AAAJKN evans_h_Page_137.tif
13435d150b2d7c3954d2eb76573e517e
72c1f370712e3e024e6bc693a73c757a8b16a864
22966 F20101209_AAAKOE evans_h_Page_166.QC.jpg
3eda4a9192bf360352731129138df47f
fd3b6b7824e4656191976d884a7611d623c5dc21
8910 F20101209_AAAKNQ evans_h_Page_153thm.jpg
8d3658578a391459009c599d18596dd4
7b1dd1b4c4c2d1b6184a95ab305e260189100799
F20101209_AAAJJZ evans_h_Page_123.tif
6f495b548c1511f8335d4c120a5a5da5
2153d2c089cfdd3037b7b319c0d7684413150ff7
F20101209_AAAJLC evans_h_Page_153.tif
9d6e05adc54125d5fd5846f1540f7983
18021ae2d66848550ff40ba3ba46ffdbd0685c28
F20101209_AAAJKO evans_h_Page_138.tif
7c1c00e61508fd54770a074c106e20e8
f237dfdf8246c8deba853ba8d3626cce2dfbae4c
21485 F20101209_AAAKOF evans_h_Page_167.QC.jpg
076b20fb3dcc74d641099baa3db879ff
93022d28f5ec25766c790fcbbd9281cc5f1e9acc
F20101209_AAAJLD evans_h_Page_155.tif
e3aee5fd251b50ddcc5209d18bfbdea2
5c76fa5f5d4ea52364bf2359e614f8209d53b8e6
5337 F20101209_AAAKOG evans_h_Page_168thm.jpg
32a509ba5b8e01b23b860fa56795c9e3
92bdbbb73d18343c1a7bb22b9371454bcf7e1782
32025 F20101209_AAAKNR evans_h_Page_153.QC.jpg
0970dcdcf635871d6aed90ad0d6f5ae6
eb13bea2634bb2010cfc244324372044b14d8244
F20101209_AAAJLE evans_h_Page_156.tif
d4eed6939365ffbff753a7e3f4e4db08
f4b34e06da4e83f642e6d75e6611137cf2665c76
F20101209_AAAJKP evans_h_Page_139.tif
f80862fbfb9d74dd1992c139cbd846a3
6bc28185579e9ba4bc17dbe8395746754dd18eb3
19564 F20101209_AAAKOH evans_h_Page_168.QC.jpg
a394db884e003d80231aac197cb008e5
c9cf98ddc32764157f96560a655a914d041bd278
4224 F20101209_AAAKNS evans_h_Page_154thm.jpg
4fef6c002f3b3302e4aa6dba97617e0f
6eb138f44b6ff79a744730250a5c59f5c7da5022
F20101209_AAAJLF evans_h_Page_157.tif
656ea633d4d147fcf776158733a25125
b27e6d32b2974b869534c1a8b31448f25018c0c4
F20101209_AAAJKQ evans_h_Page_140.tif
c936cbb637348bf03fa5fe70747df61e
a5d810be5d6f4c9b993ddaf39779452374079974
4000 F20101209_AAAKOI evans_h_Page_169thm.jpg
aa70847e746812281cf7bc5c7c79972f
cf5c579efb9a3fe85c050da95e7c18687ca13312
14279 F20101209_AAAKNT evans_h_Page_154.QC.jpg
bdcb22fce4877aab6a89f34ae097e35e
a02d9c169acef437426f215b33e0254832b35030
F20101209_AAAJLG evans_h_Page_158.tif
5490b2cca9506f5b556f8c3c2a6f3af3
3372f30f5982da085ec4160bac996fee766e8de2
F20101209_AAAJKR evans_h_Page_141.tif
75d3955ad58f1ab41d5406ff684abba1
46080f2c23cba4cda75191c6350b0e823e680ca8
14474 F20101209_AAAKOJ evans_h_Page_169.QC.jpg
5228c424c06508d9bb10f279bd303b69
07bb2742c590316a3c9b1c00c59d19c9b5bd0c80
8116 F20101209_AAAKNU evans_h_Page_155thm.jpg
433f22a6348f527a9378fa559c4b6255
67387a3a342437c64498cd9bdff2cdd17bd519ff
F20101209_AAAJLH evans_h_Page_159.tif
83a16c86aac5cac25b41675e8435eed7
d9d0298ac9d4099ad890b4e78246b272efd6298b
F20101209_AAAJKS evans_h_Page_143.tif
8d36a7e58ccf3611c4e97f2e7b0da367
ca44e7bc30f321ead5389b53f3654ee0f9018765
6315 F20101209_AAAKOK evans_h_Page_170thm.jpg
ff4a9a914d0b8825e4442299f0874193
452b0b33d26655bd61fc250bd1d9ab52cb826647
24508 F20101209_AAAKNV evans_h_Page_156.QC.jpg
4102bc5bfef628f9ac6fa697e8887588
e7fc4f3ecb04588e3517379a1a91e7edf8642543
F20101209_AAAJLI evans_h_Page_160.tif
7a2b64f998cf13a2488f12445386634d
bb96c9415eb07a8028c80bda848daee9fd21deaf
F20101209_AAAJKT evans_h_Page_144.tif
ede4df47cd3a821aad631741b603add1
addff3970c5bd8c39cd077cf7ccaf7b157df3fd9
23408 F20101209_AAAKOL evans_h_Page_170.QC.jpg
4f38f7d698d4986a1f0f1e864b0decec
848a2c8af76e78e6f4dc90601cd221d0c584a6a4
7485 F20101209_AAAKNW evans_h_Page_157thm.jpg
98ea26e0b3c0989f46a564854dce4d37
7a3f1cbf3cf91fa982d4071e197756033cee7655
F20101209_AAAJLJ evans_h_Page_161.tif
fc1c942a8b9df7f8e0037fe41634d4bc
28bacdc182f274bbcc7fbfd697f7efcdf7582317
F20101209_AAAJKU evans_h_Page_145.tif
9018736a0a973041121fd968a1acba74
531ea3e959bb0842609e01971175b50fb1c672aa
22254 F20101209_AAAKPA evans_h_Page_183.QC.jpg
385fc860fca8e0dff4716d8a4a9ebf52
2616ea75f747d10952f9fbea8944ee0b4f83aa8f
8925 F20101209_AAAKOM evans_h_Page_172thm.jpg
a05b0983487503e78563698ac15879a4
e13ec61c4cd91cba99076eda1217055e1c40f5fb
6738 F20101209_AAAKNX evans_h_Page_159thm.jpg
525728d07747ae91c9086162c3c65fd5
9ac31f52d9dc72b92b49d7b12e1c61ac8fc23bbc
F20101209_AAAJLK evans_h_Page_162.tif
e0f78a43e1763492a63d324c296c7ab7
8db6f0bca0afca73252e607d04eab7854b1ab554
F20101209_AAAJKV evans_h_Page_146.tif
09168bc76564658f215e91ea46ad9ac7
494a9cf7c50adf5c22196646c5783a46d716bb80
15950 F20101209_AAAKPB evans_h_Page_184.QC.jpg
2ae53a9529e4038c85e8554a6ef14059
65a66d032039f86ff5dc5bd8c8cb57a951124a9b
35471 F20101209_AAAKON evans_h_Page_173.QC.jpg
1b670adea7d960d4b54d29be72a4e66c
b6b06e23aba782340809ed55be0a45eea221cdfe
3623 F20101209_AAAKNY evans_h_Page_160thm.jpg
3a32790f9e8e23ab88f2dad370eece09
f34ae4e04480001d24048ea639e038bb979d20b8
F20101209_AAAJLL evans_h_Page_163.tif
484ac004c89d2a5b30a5b095a10669a6
f7006245e8a4dc48b1df9a347ab7702aa83690c0
F20101209_AAAJKW evans_h_Page_147.tif
f2e9050af868eecb92a1d991768a924c
adf23ba151a81be01f56f382c13654eb7cc8566e
16898 F20101209_AAAKPC evans_h_Page_187.QC.jpg
900a07e489ba204841aa8e243391135b
0ad52ca2487b68e0629ce8544dd4ac3064679ea0
9155 F20101209_AAAKOO evans_h_Page_174thm.jpg
0adfc7f9ee8c8ded98edbcb46167c3c3
1ef940602fc178b4ece05c5c59352fcceb9ac653
8663 F20101209_AAAKNZ evans_h_Page_161thm.jpg
527158c96d445aef9d3c3d3d810e33f6
d301f1b04bb04fe6d56b54720f407bafe501edcc
F20101209_AAAJMA evans_h_Page_182.tif
60d62d2cda553f7a525e145c6f7fca7d
e34536badcd698a288c15f7bec1746a2a3adf380
F20101209_AAAJLM evans_h_Page_164.tif
4c0572985a7fccaf3f89e1c12dcef3d1
534c9bb8884a2dd31e10f787963e1153dc932301
F20101209_AAAJKX evans_h_Page_148.tif
10f17c39fc8f1f5599a56682e5b298b4
11d88967712b53a9cd075107bd2d1f55930b540c
22677 F20101209_AAAKPD evans_h_Page_188.QC.jpg
efcde67996e8a0e62fca2a21131d0cf8
2f73dad66b8038fa5e72275d52c5d0cb8e330ae1
36079 F20101209_AAAKOP evans_h_Page_174.QC.jpg
aaa63e2c809d23e4fc1b5e33ecf48c1f
19088b47604bcc5a9ad3bc9b70730c829c73fbbf
F20101209_AAAJMB evans_h_Page_183.tif
9f8684a2c2833a06ef1ddfb120fd49ff
5ba80261d9908082fc26aef4bf8c147acc840e4d
F20101209_AAAJLN evans_h_Page_165.tif
0c9d6f9d8060db9763546166f3d44ba9
f72a1146507d8089d358af5eda6dccf5de060518
F20101209_AAAJKY evans_h_Page_149.tif
ede9728dc1ffadfa4cc20e2c3bbf4204
c9c69d2b58218b89c8e7f4e6dfbf644172e176d4
8855 F20101209_AAAKPE evans_h_Page_189thm.jpg
df3d7ca8cc8b643faa74312557398db9
f3990465b76a7fb73b284fdce9433d27ff8f430b
9027 F20101209_AAAKOQ evans_h_Page_175thm.jpg
211b6137bcfadafefb25cc8ffb01dd74
346be5d7a1a18f04153b22fb977e2019da3a3042
F20101209_AAAJMC evans_h_Page_184.tif
01bc405f5ff47f847bd85ccd15da369a
eaddce3733da9c9116ca865551ec793276618b63
F20101209_AAAJLO evans_h_Page_166.tif
74a9e1d2e670d12807ac0f278a9fb48e
81cfbef4d5892987285eef9f3e715167a763c624
F20101209_AAAJKZ evans_h_Page_150.tif
01223ed0f52525554ab3aab83f9bff75
31e0204c7e45d92657b86a798829e211782758ec
23003 F20101209_AAAKPF evans_h_Page_190.QC.jpg
65aeace4deca861c1438b6d7dbf3a07c
3f888c25fd90462b0e71cc11df4edd9d404347c9
37210 F20101209_AAAKOR evans_h_Page_175.QC.jpg
3c5df5cb778c4ebfabf4316ed3a0f791
553fb431edca69c4e5c74ecd5d498c06bc94004b
F20101209_AAAJMD evans_h_Page_185.tif
7774bc7db6bfaf27e940d965ace86198
163f46fd25655e1509553f62de8460f1d38ad51e
F20101209_AAAJLP evans_h_Page_167.tif
741705c83bdea1e9da02ab3a4711e558
fe22c9d317327663bec515c6f6f574355319b7ed
8424 F20101209_AAAKPG evans_h_Page_191thm.jpg
390c737899001763b373da3d2e4265cf
c402ae605fb5783e85901c8e9c79fc31d8fa3998
F20101209_AAAJME evans_h_Page_187.tif
e875a0fd2ad301d808fff2237ce8b990
d222287921c04618b494247992707bf743fe812e
39633 F20101209_AAAKPH evans_h_Page_192.QC.jpg
7812906ede149436b7895f47b60b796c
d05c869fa1e6366810978596c9fdf3422bbac23f
8749 F20101209_AAAKOS evans_h_Page_176thm.jpg
015389884e9bfb6282688a707813364d
bc2e3916ff5568881864ce7ad113cbd6f2af4f73
F20101209_AAAJMF evans_h_Page_189.tif
a1a8f7cdcdc3d406404668f1e6a189b1
19d700b23545f9fdde422b6208d5382d95643559
F20101209_AAAJLQ evans_h_Page_168.tif
bb8894b92f335269613d2308ab1a4205
16c07404b3184a46adc6ac49b8839efbd5f5cf18
9070 F20101209_AAAKPI evans_h_Page_193thm.jpg
3b7119ab9da2ba314bd0f58fe84349c7
920f46a9313059e84305c2161240e907c87e341e
35390 F20101209_AAAKOT evans_h_Page_176.QC.jpg
9a71d3f7b6485579055f2b5b20d1fe64
1e3606af0fbddcfa59b7a813ad1bc1706339b29b
F20101209_AAAJMG evans_h_Page_190.tif
5661dadbfd4bc666a468d42a120f8c3d
bf3df12f6a99e0f47713b0d1211802f7a53d79c3
F20101209_AAAJLR evans_h_Page_169.tif
bf440abed8f100846f85ef1f8f71a1e1
ae366bb168b0d0505e1901ab05fbc45444e11729
38855 F20101209_AAAKPJ evans_h_Page_193.QC.jpg
4278ccf7003861139fc4413c6646c157
b139901cb18d2635a2a048305fef1cbdc9c54c46
38496 F20101209_AAAKOU evans_h_Page_178.QC.jpg
3008eb67d4ed74a83a97b2510d346b55
d4a97f1bf96344b8d0e97cb2ec07b99643971eca
F20101209_AAAJMH evans_h_Page_191.tif
10a5b400a40589611737137a01ee4e00
1574c16f36997c808d042d7aefba6cdcbe908731
F20101209_AAAJLS evans_h_Page_172.tif
f00715fe9e6370fef13e24588859f205
2e856e546970ecbbff34ad34fc5ebdb7a6a4aed4
F20101209_AAAKPK evans_h_Page_194thm.jpg
91af2c64075689133e439bf8d3267e57
2fd70b2fad6e10ecdba4e595a10506b0fa874437
9030 F20101209_AAAKOV evans_h_Page_179thm.jpg
d3954a16682ecc0af7f2c26668ac5c25
9ac20d0879bced4c3acdd65ee3f1820633f486ca
F20101209_AAAJMI evans_h_Page_192.tif
baf57949540afe38bc8b6bddecc91814
167f1e0976885c7df5c3322ecc993b09f0ac9d58
F20101209_AAAJLT evans_h_Page_173.tif
4fcbe031620ead21bf27ae28e3a427b4
8d133d0cf95d07b1e7b2eaa4c753c313f5ac55bf
37266 F20101209_AAAKPL evans_h_Page_194.QC.jpg
6e62289e7dadaf7b148f6003b2119c7b
1d62ad0846e64539f146ce0259d89b4d2915b43a
36473 F20101209_AAAKOW evans_h_Page_179.QC.jpg
2e603aa585a388ff955fb1fa39f163e6
e345127d702c1d33b7a6ef6d514c5afd9e59c6b3
F20101209_AAAJMJ evans_h_Page_193.tif
25290d934b92f0c8286b3a1b76b9cf42
f321c303a0189369b574d041247382486eaad02b
F20101209_AAAJLU evans_h_Page_174.tif
4b0ff621f551c67f9a6d5d8b2efd8144
03d912fde4ad69a15c0fad16f6909908322e68a7
36274 F20101209_AAAKPM evans_h_Page_195.QC.jpg
c5025db785c8c103e1d0f103a2ad608d
3d6a6869c3e4797e9248f91347b0a1c733dc6d32
6213 F20101209_AAAKOX evans_h_Page_180thm.jpg
69fd20d5efcfc44410ed4f3921f8ffdb
53836cbbec0875bb78f50234088b251a10e5d88b
F20101209_AAAJMK evans_h_Page_194.tif
7aeff319c4dbfe6698033a4dc6807cc2
a8c658dec905393a3e31e0751c617c764439724d
F20101209_AAAJLV evans_h_Page_175.tif
fd87c869195a2258d1bc8d4ec648a47f
ced9cb42de4cacb6ad25eba24861be10e7fbe6bf
37929 F20101209_AAAKPN evans_h_Page_196.QC.jpg
b967eea7f3842608f77912a9087c8e6f
df73ef57ea10ea63f9dbfe9f0a91b86d38503664
25410 F20101209_AAAKOY evans_h_Page_180.QC.jpg
393a7b2020e26d7b0c65e5a4bea3ef96
85051e8f7e5b8a8823b6f8449c8b141ce6f854ec
F20101209_AAAJML evans_h_Page_195.tif
434dbdd7073c1163ba63fdbb238d3108
807c6502de686737d604bbf4f937332fdba28ae3
F20101209_AAAJLW evans_h_Page_176.tif
746d1754aa0352f02ab09a33e48a1916
b52c01dafe4ac2071c2e30b98a302be4ed44e1be
8922 F20101209_AAAKPO evans_h_Page_197thm.jpg
4ebabdfe5df13b0a01ec04df88f949e8
25735f5f2512751124d26d2ae8a1fc8cb4169a1f
17984 F20101209_AAAKOZ evans_h_Page_181.QC.jpg
bb3c0c1c3c02ece3b48f172bea307a75
1a5aec0d960aebdfa0db3ccbd8d6f99e8accd681
F20101209_AAAJMM evans_h_Page_196.tif
8f3a72f100ae3203963ca106ca36e13c
2ed68bf050649124bf170665a2647bae1f652723
F20101209_AAAJLX evans_h_Page_177.tif
b4d14ea1fdbaadf395ea714a4c73f893
73e7a4dede39a388019e3f3c252ae486cf163d29
61141 F20101209_AAAJNA evans_h_Page_007.pro
c154d3ea0beaec4da53f5e4b664826bb
e841c555e9b7d0b75c03193f7df907a98be01a2a
9356 F20101209_AAAKPP evans_h_Page_199thm.jpg
b82b1fa8908676a3e743779561d6c1dc
a39fe826a3469b65003ea70256874b1ebe30945b
F20101209_AAAJMN evans_h_Page_197.tif
28527892dfc70b2bc6faed4322459ab0
b35e3de8e165309d341eea36c68a804647e10762
F20101209_AAAJLY evans_h_Page_178.tif
18d3df46bfefb64821d5b2e9a42bdfc7
dd06960670c21bbfcdba7872ebdd6ecd2ca99b2e
73075 F20101209_AAAJNB evans_h_Page_008.pro
44a35f4079cacbc27aac440fc525f921
20eef43bae45c344366ee22c08e1ca8fdbbe9925
36983 F20101209_AAAKPQ evans_h_Page_199.QC.jpg
ae49ad72ecc41059d9150195a162a0e8
b6fbf856a9e320999e47ab5ce9bbe68dafd0c875
F20101209_AAAJMO evans_h_Page_198.tif
42cfd8d69009dcec409553c3ce045f35
4c8f949b9befceb66f04d101caceaed3cf22f953
F20101209_AAAJLZ evans_h_Page_181.tif
a0ca9df62ffb20721ba39b60fe39a16e
3b68c85c6ccdbb836cb629c5efd3265e908070f5
71202 F20101209_AAAJNC evans_h_Page_009.pro
1c5e535260503ff35cba7c349343b0c6
fd8c47414129dd58cb1471969ca5fbcf165377f3
9166 F20101209_AAAKPR evans_h_Page_200thm.jpg
8abd30629697babd96dad40ba8882f0e
763275931629249864b17bd318cdca5f93c07a89
F20101209_AAAJMP evans_h_Page_199.tif
b3078f15b3b81d0d2b8d0dc4291e7345
79f732d09f8d2318267400b9242f8ad89ac6ffd3
74302 F20101209_AAAJND evans_h_Page_010.pro
86c7841a1099d6f9e635024ad600c72e
f32a66f9b249a40ceb1883b6c552327c7b51c1ad
37452 F20101209_AAAKPS evans_h_Page_200.QC.jpg
75f88d34891c15f0ab0610f3979fc512
bf57398e3c2988dd39c86fcc883c24109b97325d
F20101209_AAAJMQ evans_h_Page_200.tif
bb83e34172064fa440ab7486ca7ac57a
ab63ac83192365cd09e05f26580d9a0ee7ba9384
29785 F20101209_AAAJNE evans_h_Page_011.pro
c87b0631ed574a60c8b31a156a27e0c8
91a83562ba5afb7f38fe02e46e383a00ddfdb576
44137 F20101209_AAAJNF evans_h_Page_012.pro
ad4f5ea49bde7e195bb7f5a57904984e
8d675f4095716d2dc9d0035f2d4c34dc7f7022dd
40214 F20101209_AAAKPT evans_h_Page_201.QC.jpg
d5c53543e8f046c81981f2d52d91509d
1722777101d5b16d8f8f494d604fe2fd6e974994
F20101209_AAAJMR evans_h_Page_201.tif
cb25ccc51e870f98119795f82c4d69a4
c59dd0c3359cdec82032580d6b666545a76236c1
27544 F20101209_AAAJNG evans_h_Page_013.pro
6f38fe816ee81bc11ddfe5d752922ac8
bcb665311e1086af3bff2dc2ce66f1f4dd525554
35830 F20101209_AAAKPU evans_h_Page_202.QC.jpg
cb91af9ca7b06178778b60555509d615
11cc0591f10ed1187d1741c727e9c2ec9b29437c
F20101209_AAAJMS evans_h_Page_202.tif
1b1e5d09547060709054a4be98431693
4f9eb4377e5abebfea144e197429ec601b2f0538
49572 F20101209_AAAJNH evans_h_Page_014.pro
2af2ffc6b04c86de7c58194bbdbf6a2f
254a0b10cdc9e23d675da8ec069c9d16920188ff
3101 F20101209_AAAKPV evans_h_Page_203thm.jpg
43a135104d137df88ea39aca6b9e3304
e8f8d24afee58d40b9fc87f968e80feef4f21439
F20101209_AAAJMT evans_h_Page_203.tif
7e61c70771f4a633f47b5266eac14115
42f83c4e496c63a251c0c1c0eb1ca4d486db1bd2
54055 F20101209_AAAJNI evans_h_Page_016.pro
84d3fa43d56ba6cd4009b41fb8b5a342
515ad722b2c577a9a31c54791422f1032229f94d
11971 F20101209_AAAKPW evans_h_Page_203.QC.jpg
eab868bf071907432f4f3c897b55e132
4bf774b2cf55de8989741c9c1b342acbe0457394
F20101209_AAAJMU evans_h_Page_204.tif
c5d2e9809bc0bcba3921e4e0692c958e
1562330db4628d5b9d56d06c9a64cc07d7f04ed8
50925 F20101209_AAAJNJ evans_h_Page_018.pro
9b0c5448e9759abe62f43f99139de4f6
c4beb7588db034e1420ab6b7b49298daa059bf4b
26540 F20101209_AAAKPX evans_h_Page_204.QC.jpg
e56f27d818c24848d2a497e45f32d316
87c3ee5f71e984d04b803c5607ea3e7040cd36c8
55131 F20101209_AAAJNK evans_h_Page_019.pro
7ca7af6b514e7e32e8b494bbf96c79b3
48fca814e178c2c873a7ace8045f4e752c9356bb
1148 F20101209_AAAJMV evans_h_Page_002.pro
75d54c8e939b15e9e8782f93721c0c8a
a0b5ad487d8b09fba34b2789c913749e2356ade1
52613 F20101209_AAAJNL evans_h_Page_020.pro
73e41f978e67890861ab7eab5c743e9f
419cc702bfcdcb021827937671b98b471e43c4b8
728 F20101209_AAAJMW evans_h_Page_003.pro
164ea6115bf3368e60d897804c756e72
92dec689ec1b02ff21e9558c1ca4339362e3c0a4
19262 F20101209_AAAJOA evans_h_Page_037.pro
15887a60674f72c6329d07418060e1f5
b1a69446e016b5375d511db9e762b46ea8807342
55427 F20101209_AAAJNM evans_h_Page_023.pro
527d0c4bb103091f09fc22415d9fe940
c45602b66ec7fb057e696063e5207b9cf9e726c7
52620 F20101209_AAAJMX evans_h_Page_004.pro
2940d994ab1e21699e73f574b01644a3
93cb7ce7be7a8f1f03f99e2a9dacd9e4943ee6af
27159 F20101209_AAAJOB evans_h_Page_038.pro
c9e8987eafdc3ac8c18daee64f42c0b3
6cd32ecfa58be4926e9e2dd1c0f992f1f5f882a1
55861 F20101209_AAAJNN evans_h_Page_024.pro
3156a71cae775216b7bfeaec4194357e
c5d65e3022487e4d9625c4a806f0d85876912196
88065 F20101209_AAAJMY evans_h_Page_005.pro
d4995d35814aabf32340369b8fca0dc4
788176adf533e42c161713964a18ef4ba37d99d6
18763 F20101209_AAAJOC evans_h_Page_039.pro
9cd9d328eb383d0f88d39b479bf945f2
20511352d2ae4921e1276f016d0da2cac1d3abbc
56231 F20101209_AAAJNO evans_h_Page_025.pro
3a92b58166649420c7427eac5125bb24
7a3c42887ae0e9844358e43bb705a310f52648cc
88594 F20101209_AAAJMZ evans_h_Page_006.pro
81f1708d6f619623a26b56d17c935563
f6897f365979e4f3c955d7554e05dd0f2dc92684
29552 F20101209_AAAJOD evans_h_Page_040.pro
2451cea036e90c75363859550ff957b9
49992d1bfa2f534b7aa317cbc3a2a2756ce98028
56109 F20101209_AAAJNP evans_h_Page_026.pro
aa1757f9887ddfdf729038561874b285
ab723fa287bfd2c244c9cb08292ebb00181fe0ef
22457 F20101209_AAAJOE evans_h_Page_041.pro
029e41affb4c6a8d5817b1c330d0d097
f8f8887c9267d3f2eaa2ab30d58a5eea640f7b3b
32503 F20101209_AAAJNQ evans_h_Page_027.pro
cccb52a2615f12300ff7bd7789344832
14368f45bfba5ec4a8505ff70ed52402ab16a33c
42098 F20101209_AAAJOF evans_h_Page_042.pro
32e8d66966cd32aace951bec6b9f739c
4500e5a815ea791d53c1362f03fd75f50e91921b
14144 F20101209_AAAJNR evans_h_Page_028.pro
bc97b94cb56e839702f356abb3ae4754
452aae08d0d6f8029eeeeae919e67d162dac1e31
40383 F20101209_AAAJOG evans_h_Page_043.pro
c017d8b0abd3871808b9156db301a7c9
10a5305c07fc15ade9428260c60cf20e64240ed1
43084 F20101209_AAAJOH evans_h_Page_044.pro
bf2daefe2deee7f25349dfe52b25e09f
0e163c39eacf36e137e570b95cc600371d6cec9d
56693 F20101209_AAAJNS evans_h_Page_029.pro
bafb6788a130c8f8f2bbe2521c944852
25c917e969fb9ec25bcba8f1abdbe4e685686af2
35597 F20101209_AAAJOI evans_h_Page_045.pro
2fe20fc426167f8883ec401d0db1613d
572a9d45f061a7998cf042c6d2f2ad20ad843f93
63923 F20101209_AAAJNT evans_h_Page_030.pro
052c2475dbe7a4872e6cf7f593852f0a
85d1f6a5b317ba15cbea446387a4812c0ea8afb5
23884 F20101209_AAAJOJ evans_h_Page_046.pro
ff87195837a9b4180403ba96ffc4aaa2
023131c2d13b71b5a58985659ee0eeedc606ca94
40108 F20101209_AAAJNU evans_h_Page_031.pro
3e8ab26afb6064d799d2b93fcd788976
9abac9cbd3376732b6c66acc181f7a0aa120f3d8
20906 F20101209_AAAJOK evans_h_Page_047.pro
642dd6374b8587b22c723675c7833eb0
a42964dd323712dcc1ae512c5289240140f4f11e
2927 F20101209_AAAJNV evans_h_Page_032.pro
90fa490f12bf3ed93e887b4c1551a9a2
1311f350195906dc36325decb79af975666ce2bf
53875 F20101209_AAAJOL evans_h_Page_048.pro
1ca29f3199709c923703da9faa4241c4
9acd45e651f0170eb86e9b68f13c7744b5fcbc6b
32566 F20101209_AAAJNW evans_h_Page_033.pro
0b5d93c2c46ceb11cf39ab86858bc810
e8d0f56d18c9613027d0357bbb1bff07e41d8f1f
55163 F20101209_AAAJOM evans_h_Page_049.pro
35e3f02bfa8da7f50fa259cb35898f51
7fce398f72048a09fe1707cc7b2cfdfd8fcbd072
18892 F20101209_AAAJNX evans_h_Page_034.pro
f53ba7656493c79958af16dbed00067e
a1dd19f44b703137bc84e3f45d5963430fc9d03c
15909 F20101209_AAAJPA evans_h_Page_064.pro
73fe314c19dabad9126bd3717bfcea72
2560aecd90fd3c8ba4ced3ceab49522ad642d304
49272 F20101209_AAAJON evans_h_Page_050.pro
c23fa16120bb35c832c8f056ce03dbeb
9c7422dc74ab52b20e9ae15033b51cb4b7a0e34f
26671 F20101209_AAAJNY evans_h_Page_035.pro
1e96cb63ede5636971084e22dd1cf5cd
0f3138769ec93067708bc16905bf2c5dad169037
27411 F20101209_AAAJPB evans_h_Page_066.pro
2df0d203859aa21154c77d9a3dd57c33
1c9577dc3f9c594680a9f7ed6c214f62eb090b4b
54750 F20101209_AAAJOO evans_h_Page_051.pro
46bfd751daf111559e497a7a5215cbb4
14daf2c26ca470755d7a836cdddd10a7e54762c1
14779 F20101209_AAAJNZ evans_h_Page_036.pro
acca6fe9ace92cc8db0936ccf8ff46dd
d446119230326bc82ccafd13e693d718afb44e12
21498 F20101209_AAAJPC evans_h_Page_067.pro
0944138703553df66bd6ae0d36053065
fdbce45c4d043c0bd05f2cc72fd9291b9450e594
53096 F20101209_AAAJOP evans_h_Page_052.pro
29b5a8d7a2e011c35e87a338c5dca72d
85bca49d125b33d04f0e857dda9797223bcdd205
21947 F20101209_AAAJPD evans_h_Page_068.pro
3282fca58ba7785b3c1735bafb97558f
9b314fe1359b23c16abddf0b0fdb11193f9fc5e8
55391 F20101209_AAAJOQ evans_h_Page_053.pro
a81b47b306ed48129a670ce882b8aa17
1ebbfd256350d47c284d6960c49d36a3e07fa71c
11652 F20101209_AAAJPE evans_h_Page_069.pro
7bb1f01434624cefe5f9766d16c15773
caa92f05e054c8aba62702485eedb12bb10d6816
54347 F20101209_AAAJOR evans_h_Page_054.pro
365befa96b3207c13b649d8b0fb31181
6d7f8da1055a8396dc3469cb72b5ad92db047b27
16134 F20101209_AAAJPF evans_h_Page_070.pro
b0e166a6e0b1e98433bb436ae7356b56
10b37d6344fe7d7d6c67cc90f78618372bff865c
55363 F20101209_AAAJOS evans_h_Page_055.pro
558ce46f50469c2d5d97d801043916e0
32a8189cb765ab60992554373edcf807ed66268b
66187 F20101209_AAAJPG evans_h_Page_071.pro
2ed62235adac3f7b8f9abb61335d7eb4
a79ec579a87d9ee79246bb9371335dc1f7d8fbd2
41613 F20101209_AAAJPH evans_h_Page_072.pro
b4e7ce78a866d821ea9236fdfc5fe2e5
225f7dce547a36ad88f114c2080a6aa5a01c0e66
50837 F20101209_AAAJOT evans_h_Page_056.pro
5931674a0ee2afca88a0078d182fc892
8d37bff48c745c31ceb0c9dde62543f978114c7c
27680 F20101209_AAAJPI evans_h_Page_073.pro
d33a0eeab3f4dde4b565949bd4a6185c
15563a913a009095f8810f2ae7cc6b65d1ab3c30
43897 F20101209_AAAJOU evans_h_Page_058.pro
a134ae81c1c01ff6485bade6fef5bb9d
3ee917bddf9627a68c73b888988f06b7ec3e246d
38522 F20101209_AAAJPJ evans_h_Page_074.pro
912e80780df3cb72623759d5bd2190bf
bb9cd75871df8295723528c39b00506fda84b93a
41970 F20101209_AAAJOV evans_h_Page_059.pro
014645184ee97a601e775d7204c515d6
d6435704b345a7ffe7361a21b0dcbbc49ab61327
52911 F20101209_AAAJPK evans_h_Page_075.pro
81b71401d3e1cd7092507fc93ae6c5ce
9e1e3d6d9ebd494eb958ba18e97eb7ceb3ed3744
60317 F20101209_AAAJOW evans_h_Page_060.pro
60f3f4562a24bcf29107db5bcfcc04fd
687346776e61c93352848eb19ec422548366ab26
56226 F20101209_AAAJPL evans_h_Page_076.pro
be1998c8bacb675f7265601ab172f1ad
7407c1b17f6ea1c8e04b5239ca0fa87202970fd4
51811 F20101209_AAAJOX evans_h_Page_061.pro
86b181b64a437b8394459e56266eec6a
3c93687d4df23bda361d20d7d82aeb821d3fd853
38865 F20101209_AAAJQA evans_h_Page_094.pro
60130a116b1cb117d8b16bffd22576f0
7b862a69e76c21da79bc85642f0acd05b7a97356
53849 F20101209_AAAJPM evans_h_Page_077.pro
b0c28cc64d42e137e584b1c5b9d0fd99
b8d11471f43b06481911738fe9f1cac56a301519
66034 F20101209_AAAJOY evans_h_Page_062.pro
81f8ec74102157222b067ef5159e7199
f5ccafad075ab032336b6b3412e2182c0718e6ac
19306 F20101209_AAAJQB evans_h_Page_095.pro
a2de4a33fb23b80c7728f55c8de47099
fbfa60f7b93354f59beb509020d87da672334eac
45189 F20101209_AAAJPN evans_h_Page_078.pro
8c5d245dc8602b8544d38dcdc57e7707
7bc04b51040e115d7b8a70838777d30983539edf
41908 F20101209_AAAJOZ evans_h_Page_063.pro
d0d683baa7cfa934c57b56d2ae82f458
6596ed32bb71a1c1b30757fb19c56732bac5a39d
112326 F20101209_AAAINA evans_h_Page_111.jp2
4e3fba6dd815a4022e4fa4610c07d3a4
233d5d367ee184b8c801f3da10e3db21b4ab0f43
24931 F20101209_AAAJQC evans_h_Page_096.pro
51d7ac1709dc12951bb4dd051abb4a02
067fd4e4e44bbc396c0eaf66ea85b35f8256747a
49260 F20101209_AAAJPO evans_h_Page_080.pro
7707a1280c7a4d3a2a3e3d25a5c774e2
344be0dc12e5f48b33d5aa06788d2ea07022d580
112452 F20101209_AAAINB evans_h_Page_083.jpg
bff81adf55ce71c05147e84860036039
3f9b64ba045dc5283ad5edcf8456e5815d194b46
16607 F20101209_AAAJQD evans_h_Page_097.pro
407b216d8c9869e698789859a1535ad9
5a36966f87a608d8661b3b3b08ab6f4e59fe622c
52073 F20101209_AAAJPP evans_h_Page_081.pro
19cc4b23b2ff5233ce50de269c3558ea
256f3a9fea12401d128ab0cd2fd5fd8d00e8c1a9
593 F20101209_AAAINC evans_h_Page_102.txt
acba6b6552a51a8611ed56e5343c1ebd
ff5ca7d6f576788b40a8e98e1294b97809869855
10939 F20101209_AAAJQE evans_h_Page_098.pro
a26683f67135f025f00c5772d4ab1343
1e461bf5cbc10867cd0e888b662385d3877fe07c
50585 F20101209_AAAJPQ evans_h_Page_082.pro
d68889f956e1c9ce4f9e11a3389d3f50
929c7b963a50e19664b7d1f90f9b7afe72b144fe
F20101209_AAAIND evans_h_Page_023.tif
17d1bd49ac331b311bbce3ae75f08491
e469d01a836a2ceb1ce5b4079aefa58d7e9e5261
14352 F20101209_AAAJQF evans_h_Page_099.pro
432e581a56c51bb3fe3d7ed209515bac
62f68e5cc5798225053a5d608e4de6a17aef6664
55078 F20101209_AAAJPR evans_h_Page_084.pro
5157e752f8e1a643bf63aaa1a5385406
7f173aab2b34c55a14c3f7a5857b32e0ae9c10bd
F20101209_AAAINE evans_h_Page_022.tif
dfa4a6017712693edacf3c153c6657e4
1a6ce10656e4b57a6dbde48a8337cd85a724499d
14021 F20101209_AAAJQG evans_h_Page_100.pro
72467fd397e51ec076b56e7b1f7a4734
fae5286970b87bfce7a832a3e32f32711663ccf2
54000 F20101209_AAAJPS evans_h_Page_085.pro
c7143da169dea8394d53d406ed7cd94c
7c335c233f05fc07a6656d922a6b6d84311d0a00
F20101209_AAAINF evans_h_Page_154.tif
5b9bdec3e1777319e041101c7fefdd64
48cb491c0b7bcf52bbab4937c00076cc97f8524c
23765 F20101209_AAAJQH evans_h_Page_101.pro
17a9b3bee21f4ab8c3e2d50be771e117
3addde02923b433b436350d9506d976b06e9f446
52909 F20101209_AAAJPT evans_h_Page_086.pro
2435112405a98a44ad174dd6c4207dce
424c6c350b477242317f2129f0cd40d90c141831
F20101209_AAAING evans_h_Page_025.tif
83dd5f67c2b2e4efb8bc032d6befbf39
925de829a31774a750bd2e30994e799d06c103cf
11205 F20101209_AAAJQI evans_h_Page_102.pro
6fa50101b9c86ed8a0ea2f455c5c23e9
9b2336e752f121aff634d4dc853fe4c0eeb5d2e8
F20101209_AAAINH evans_h_Page_054.tif
e8d6971c08952647b07588a5078c2a4e
584b9ff3e3a7b95e7117311f8a37740be24d5e03
20439 F20101209_AAAJQJ evans_h_Page_103.pro
3c9f16df406ce72d2b8ca76ef9ee5c1a
02cfbb292d8811690fed76545530f69faa1ea608
56967 F20101209_AAAJPU evans_h_Page_087.pro
aebaeeb3fd08ea166fbf683208c5d77f
328590e2c86729c443d6969e547117f996b4b31e
24390 F20101209_AAAINI evans_h_Page_001.jpg
1d1945470c6a3389212b4a6bf8cf92e7
d62d00673af65630975f774e2e28246347c24542
11223 F20101209_AAAJQK evans_h_Page_104.pro
0a99234aa63ddbb6a61862c7d654558a
65187deb3c0c877022a34d3bf969c078fb3b6914
7482 F20101209_AAAJPV evans_h_Page_089.pro
b2faeac7d106aff7351a1d4af2849611
51bad9dca6b3912b3812732f14f2993e30bafe7d
F20101209_AAAINJ evans_h_Page_170.tif
c3a922ddec582b0710885a9e2d1eb6b0
5a1c87f1c6220f4d61ed1cec5dc9a22d89a2bdb4
53337 F20101209_AAAJQL evans_h_Page_105.pro
e28980de8a9804ba9fec2a670e46c313
ad359e530797948aba0df7674f239feb82aca439
35501 F20101209_AAAJPW evans_h_Page_090.pro
00f452beffe4d125285023481fea615b
8c9a61e48f66878a3d4626d6a6d7dd4a20b69682
17822 F20101209_AAAJRA evans_h_Page_122.pro
90c2c2e76a4a42333c540e33a283351f
62adf5b746e73fcc074f2015b7058bfc3491b40e
2207 F20101209_AAAINK evans_h_Page_084.txt
68d662d6eb8fa661f92e04663ca97981
cb34ef80a27029b9e6a1df14cde0c3a5197e8de5
54753 F20101209_AAAJQM evans_h_Page_106.pro
612677058e7d60bad5f6d71c18356f48
0ffc5a0b3ade8b49a3cf11ee1bb5f2ff334290e2
54900 F20101209_AAAIMV evans_h_Page_108.pro
68c15f6512f304881329a75c68183080
d6f036c026872dc24351b7536ee4f44997922ca3
24449 F20101209_AAAJPX evans_h_Page_091.pro
b1bc6768eb682bb0b1046589da3a54ef
7a2c614995c62d454dc8cd0b890607e897341100
15594 F20101209_AAAJRB evans_h_Page_123.pro
d30dd1eb37191170de9e365c9000181e
0bc94a79a322a2353427f979767332c807754b8f
548395 F20101209_AAAINL evans_h_Page_120.jp2
d18412f2fed51f4e4452a6d368e9920d
2e791a1070ec7a35d23447669532245f94e6ad5c
51740 F20101209_AAAJQN evans_h_Page_107.pro
14430a5c993de2fe2085bcbdd4043e85
2c1aafb0b66173de5de1f594719ea21f8b10aa52
36883 F20101209_AAAIMW evans_h_Page_106.QC.jpg
4253c6c524cef92d73ac646ffbcbc492
e5e9533ae1db837906fa51787ad7a5b1691a4271
14348 F20101209_AAAJPY evans_h_Page_092.pro
c7d1e5894052eef7d7b1cad7ad743c84
375358c9f74a9664040993588e2d1630540e2f16
25905 F20101209_AAAJRC evans_h_Page_124.pro
e49c2a45d10a6612776fe1607c79750a
1b302f3284bd54ef2cd1b31e1431a17f451089f0
115373 F20101209_AAAIOA evans_h_Page_176.jp2
7caa69ec1f000f2f6707636d4efadb3f
d7409e2ce81716646a16a07dcb8c62c38872fa8a
107317 F20101209_AAAINM evans_h_Page_079.jpg
d02092860bbd29b840f0e658561b41ea
d6ea21134efa443726f981b32cde9059e2961e14
53401 F20101209_AAAJQO evans_h_Page_109.pro
bc4316942d7caaed551fd5aa8f3049fa
ebc8c374e9e364488a9a14df5bdb57ecb78dfac3
6107 F20101209_AAAIMX evans_h_Page_097thm.jpg
6dc0070d4c8635e350d59d52f519bcf4
b80fbb03a1dac2506b87ec89acc26317d45c644b
32809 F20101209_AAAJPZ evans_h_Page_093.pro
38c4a3158307650a078226add07d6c7c
62aac45547adc3d26a343add3611cac5c0ddba35
5665 F20101209_AAAJRD evans_h_Page_125.pro
bb2efa20ddc0ae583c55bacd10a6909e
3fbb07693197f3d2b89c80268e81e6e5495d8705
F20101209_AAAIOB evans_h_Page_062.tif
d9e7d4f7eb79ad5ef16fce863514060a
789b5c07381bc1197b82d9f3c8c728032f632477
28138 F20101209_AAAINN evans_h_Page_104.jpg
03efffc315b284bffd9637c08e7b8c12
753fb0e4b0a8f06cfbeb372dbb4457dda2f2e0dd
53936 F20101209_AAAJQP evans_h_Page_110.pro
03ae2d5165ec025810079f53397bee96
f207c023f93a9e7f4315742db85e49b4d88772d0
1051930 F20101209_AAAIMY evans_h_Page_007.jp2
e0c386b1561953123ed24af2387f61b5
54a4cfaafc12da1af3722a28d4b7903493973fbd
13623 F20101209_AAAJRE evans_h_Page_126.pro
f534b9da92fc1c1bd5bbd726ea94b94d
c14f39ab32bed446abfbdfce4acbc5d28710b453
F20101209_AAAIOC evans_h_Page_106.tif
58bab4383e607ca7f3147061f969b08a
8a126a9396b8149d55a2b20d76e9fc85a1a2a146
2139 F20101209_AAAINO evans_h_Page_179.txt
e1616c2751ea35b6ea77bbee6a83b966
902f53141c7f6eb21d34d3cd12fdb15ecfd38a79
50744 F20101209_AAAJQQ evans_h_Page_111.pro
40151ae144105499203044facb58d850
1fb62d0c94928fae08f95318649246c504e431d0
85485 F20101209_AAAIMZ evans_h_Page_046.jpg
de24162731a6a48ea2a63e0414f19d27
2e8d8bb2d76aed1c0f30fa950bbac3a77310ecc9
19480 F20101209_AAAJRF evans_h_Page_127.pro
8eba4a62a4a9dd9293b6e8d9c8809757
2a5664ba94eb2708ad695c4a7723853312c8d4f0
14905 F20101209_AAAIOD evans_h_Page_129.pro
e41ed6b1602241c29b87d95bf15061a5
5db575729db34975843adb6d95b1fa45127284d1
F20101209_AAAINP evans_h_Page_142.tif
3cca63719c7e7117b631a4022795fab7
0bc82d0611ca44fec685043844e4a5fd378be941
52560 F20101209_AAAJQR evans_h_Page_112.pro
a2493ff9615e304b90cbe4900c2714a0
fc5e37b4cb3fb226fc61257e41fc41cd8b5c0ac5
10787 F20101209_AAAJRG evans_h_Page_128.pro
7c50635107c6496fa93a7559f501ba13
0e3e116912d4085570f0551e54c6f273ab723198
15901 F20101209_AAAIOE evans_h_Page_064.QC.jpg
c620daedea33d9100de40032bd8491b3
cd9e01f4dbac2002742a249284535c31876047a8
45156 F20101209_AAAINQ evans_h_Page_068.jpg
292793ccb76a9274ff7ab28b0abe64b3
366e44c6cf291f2e7a6d84d418c10b925ca00bff
55051 F20101209_AAAJQS evans_h_Page_113.pro
526c10936699f04f24e2f8919bcc1a0d
9f20400587caec39466c34c95f6430cfb26c6346
31758 F20101209_AAAJRH evans_h_Page_131.pro
16812d00ab43c9d29e5cedf818430744
d9ede615f59aafbe9586bf2bd7d5af0518a30e4c
366 F20101209_AAAIOF evans_h_Page_186.txt
93725d781f4f2bb30c3641473d735182
71be9d5818f648a916a7cb626863615b121530fe
25550 F20101209_AAAINR evans_h_Page_159.QC.jpg
6105826d109b13514e614764024d90a4
dccd75cbc44458b81149eb44c35883cf2e3a92f9
55063 F20101209_AAAJQT evans_h_Page_114.pro
d46b2c1934e68664ed20934a6e898206
124f56906a3f44b1c9bd32cc47544ccbbd170fa0
21859 F20101209_AAAJRI evans_h_Page_132.pro
4ccbb3789b0c90d518b013d3b288347c
f51281741834d4e982b935c4b4d173ac17f8a636
F20101209_AAAIOG evans_h_Page_020.tif
00bd1450cb0b1de90d6ddc07ebbf65ad
394800b8b999b022d6084b8c07235f679955dc81
22698 F20101209_AAAINS evans_h_Page_040.QC.jpg
08f53bc6b9d25664d336ede2ae0b1b71
553855ce9e6aff5560fc5633236f8e7a3632e2b4
54180 F20101209_AAAJQU evans_h_Page_115.pro
f83bba73f5eca7d559e0cd34f42950dd
3380a4b6913c88c1b375aefad12a25ff2b9257ba
16971 F20101209_AAAJRJ evans_h_Page_133.pro
7c6228f8746d44827b6a2d5aa8bf803d
25feb9b414e0204148bfb4ab7a210284a0ace2e0
23085 F20101209_AAAIOH evans_h_Page_066.QC.jpg
7a30e3c1845b51dbec680ebaa6edad77
0143dcc857f7d9432af713d7d43a8439fd572fe0
15806 F20101209_AAAJRK evans_h_Page_134.pro
27bbd94b07d69111e87ca1ab022998a2
5d517b2bd0e65aeb02de665f40799e6463e96c03
13911 F20101209_AAAINT evans_h_Page_122.QC.jpg
0d372dc2cb83a777b322f471ba7157e5
6bd55f8c6c6aca0eb1a264685dfc8c638321e797
56324 F20101209_AAAJQV evans_h_Page_117.pro
ed8f501b48320fa68d52b8f01c37a00b
e7e43ab31ff1ed96d4a1d212053e165e250cd75f
110170 F20101209_AAAIOI evans_h_Page_139.jpg
a7e4f2325f74a4e12dfe4c06cb12b25c
a5a1e43b7924ab8bd6b62ca3ca468e349663aabd
11586 F20101209_AAAJRL evans_h_Page_135.pro
8437ccca0929ee34d4cfe077b9cf9c32
f2c49f64c736870a962cc05984707d603d81bf6b
604 F20101209_AAAINU evans_h_Page_187.txt
865a9ca3964325809a6e25e70ed03d1e
c8938b244ed8344fd32748f6cfeb5ef8fa239002
52695 F20101209_AAAJQW evans_h_Page_118.pro
19a13181daf1713bcd759c489c4a019c
9568790496b64a06f8a8a95c936951cbd0499b0a
11627 F20101209_AAAIOJ evans_h_Page_017.QC.jpg
9786748f25006cda186a7050ccf64ef6
51366455a18797c87e7bfae0fb571d5f54a527cb
16433 F20101209_AAAJSA evans_h_Page_151.pro
c1e4a8ad4cbc81ed9ed7d86881d63302
94c8e20612dfec3ef1f5d1ec46402495ad9a71c1
51795 F20101209_AAAJRM evans_h_Page_136.pro
59ddddae864a77ae1b4af3a12992e59f
b703291009891fb141ebeeea4efde0c5293cf5ad
27089 F20101209_AAAINV evans_h_Page_062.QC.jpg
3f3d07695bd877f94fdda2cce099eaaf
a99d0b52bd732e10e2b0fc3eb19d32e200efa5ce
50068 F20101209_AAAJQX evans_h_Page_119.pro
209f9e76e3acab10c45a4395226f09b6
b342e9350a75f5219ee81d7ef5afa5b725adc673
37079 F20101209_AAAIOK evans_h_Page_085.QC.jpg
14446bea063d4a44e77464b29c5143d6
c1eae7b4c08f14a553f117e595de5aeb8436da8f
16337 F20101209_AAAJSB evans_h_Page_152.pro
8b14b95949c129aa1db5baf0c2941cd1
9405324347b7ed2e045d5ed865cff17d1f8c6b47
50856 F20101209_AAAJRN evans_h_Page_137.pro
caddbeeac5da237dae63895c4b832101
76c832f73a722e976b78c88e608b9d659b85501d
20956 F20101209_AAAINW evans_h_Page_097.QC.jpg
1327d7d88e03ea1cf3d78d66a92378ca
191be317670907d6468abc06fe534cb340adc455
24209 F20101209_AAAJQY evans_h_Page_120.pro
b73573c484100159f2a15b9113d3b310
f324529f7ad255a0bdb279f723d0ea94cb02fe60
F20101209_AAAIOL evans_h_Page_105.tif
cc5396d6a518e8aaa6a3788d9a90ef50
6914b599a016c52a637c06dd721a8aab409d5cc4
22531 F20101209_AAAJSC evans_h_Page_153.pro
18acd1b8d8353234a479e1307a7dc834
df7c610d46b657efaa0d5e6eab2a983ddbe18c71
53681 F20101209_AAAJRO evans_h_Page_138.pro
0f268873eb8b4b7ddf4d62aac779360c
86eed73c31a48e54b0a254705735f9543cb056a3
8535 F20101209_AAAINX evans_h_Page_158thm.jpg
62fe8bf85fec281591887cb8ff7d7ec0
59abc1c5eb77b456a504fd2cf83d24cba1cdc486
13867 F20101209_AAAJQZ evans_h_Page_121.pro
4c2354c1d6196630cdf67e238ce94318
151dc2f8460d57960ed6c011e378cb143319fa4a
40499 F20101209_AAAIPA evans_h_Page_198.QC.jpg
317f261a58abe415ac0d565d21e583f2
f274b059dda958e93e8fabfdc8e7d9abc3b4fbaa
F20101209_AAAIOM evans_h_Page_067.tif
07b6a6a0438610ab26c099fe53f629dc
7ae1e372d7f28c9a9fffc99e9c5d42f43ce05758
7978 F20101209_AAAJSD evans_h_Page_154.pro
90358a19b040069ba826fa4fe4946435
0a54b9ff4b704391877fe85f07e6ec6586010935
52971 F20101209_AAAJRP evans_h_Page_139.pro
661110d3ad7c92430abed3bbf54b4fa3
b69425d7a65a994850613dd171338072e7842b3f
20674 F20101209_AAAINY evans_h_Page_183.pro
e588cbc7b4f4a74ae4060802db8313bb
cee438fd25c6d7b30f4556073e9b42ed9946e0da
62627 F20101209_AAAIPB evans_h_Page_099.jpg
fcabe7cb27fde8601de789f9a7e1bb6f
9fa96d649f875e9004543732060c3d4106b2cae5
116892 F20101209_AAAION evans_h_Page_109.jp2
3785f356f4dc07cc80ef15f18434de94
36125c0694c97f205a7ac9360e8c6c529a548869
16027 F20101209_AAAJSE evans_h_Page_155.pro
f932c1fd08ef1239ee1241b8e01f8c5d
a64762d35130b8dfea1954f7162d16f451c1ca9c
53052 F20101209_AAAJRQ evans_h_Page_140.pro
bb283202fc88125863f37487e90a668e
ce7354a33f20e9142ae2abbd1adbd7a9efb0b309
35178 F20101209_AAAINZ evans_h_Page_017.jp2
e3c9887c6e33cf5e7bcf2f9e7e55ed6a
12acd43df69a7d31f5311ac24e24e6a50b5a22d2
101323 F20101209_AAAIPC evans_h_Page_050.jpg
e4b5611317fc1a02ddb5b36d60985ddc
e602b2462567ad81b7f3d8fb02ef8669afbe2377
54316 F20101209_AAAIOO evans_h_Page_022.pro
b00d4a0e41c8f154514afac8314e6993
6943594df51d6ba2cd23fd7c08981d215d3d30e9
31200 F20101209_AAAJSF evans_h_Page_156.pro
6fee731360fc2eb552ec81e1a82e4c40
2c9c7f2c2a02072ef8e4d0c00072fc0f9940ca00
53549 F20101209_AAAJRR evans_h_Page_141.pro
e981aa5967191183186a07ca108bc249
329fc8ea211df100cb0b5def99f234eb5d0f5f22
7934 F20101209_AAAIPD evans_h_Page_001.pro
befffbd8a86ca13c5387e6a101e955b6
e96b390e5e548fa42d0b382b2f26348041c36167
51001 F20101209_AAAIOP evans_h_Page_015.pro
18cbddfb82db0c2bd6ca2fb5c8f1685f
5cfc02c75e940e695f653ddc4f685463c6c70de8
13235 F20101209_AAAJSG evans_h_Page_157.pro
dcfd7d8a79cb9a9f48811a42278af0a6
0488745d0518de03c73a9a42dd53ecada487fbc7
56807 F20101209_AAAJRS evans_h_Page_142.pro
2e3ddcadb197b4c74192fa53834be82e
e5996327ad1c40b684620b5b7b10f264834b7851
7813 F20101209_AAAIPE evans_h_Page_014thm.jpg
b5a9c34503911627c553d1da72bb3103
653768e4e7dd581a5e84b9a06b31874ae117dd17
117106 F20101209_AAAIOQ evans_h_Page_085.jp2
536190e33bdd513abe8977cbb642d4b0
a7251232d7e4480c734f2273efae9bd5bb1bb3c7
19102 F20101209_AAAJSH evans_h_Page_158.pro
38546cdeaf3743f14f85a94f8a8323a5
7b1e3abcc682926b47942faa6322864b999f3124
54212 F20101209_AAAJRT evans_h_Page_143.pro
9e09d32f65327b54c4fdb1a165e11723
299b47d627c96aff02dfc9bfa929664379b1d413
15077 F20101209_AAAIPF evans_h_Page_017.pro
11c106a86359ee32fd856b987986b3ff
f7d2b6a51e97facc099e3fdcc57a5fc2bcad0822
40866 F20101209_AAAIOR evans_h_Page_147.pro
b963998f05e3454edbe921e824ed5045
7e3101157a9fb686fc527521e953e1a2f2aabe76
16137 F20101209_AAAJSI evans_h_Page_159.pro
379397a69705b4f5c38cfe9f7ff4092e
dad6113dfec63edcfa511aa430bef5c38fa9566c
55096 F20101209_AAAJRU evans_h_Page_144.pro
facd9d1e8524e81528a542e948640a87
e3f41729e398e18fd2ced8648192f107ecc43f14
2020 F20101209_AAAIPG evans_h_Page_015.txt
e82c4e9dee1ab52e687cfb3ecb1d05af
375150493eb507a0d403beb78d5a53392142760c
108291 F20101209_AAAIOS evans_h_Page_080.jp2
37bad3ae5f6dbc818eeb95fdfe7d6829
2c4189634d8ac8d3081c210619bcd21c46ee058f
14201 F20101209_AAAJSJ evans_h_Page_160.pro
864f290d27991dfe808eccf33df14b0f
6b43f7930c3584ced658941d30d7cfb8e602b5ab
6660 F20101209_AAAJRV evans_h_Page_145.pro
a82d17fd3cc8df35de0ee00c488a646a
5e60b2f877699270118730c2968ea9f0a13991c5
23101 F20101209_AAAIPH evans_h_Page_027.QC.jpg
1078e50da2ba2396803689fcadfa5a36
eeabc1dd4a79d5059e351dfa552f6a58a9c53191
2173 F20101209_AAAIOT evans_h_Page_049.txt
0a5093ddbb20aac38b46fbb0ca122280
f5fe3372656c7fba0228065d928f7506eed89722
51614 F20101209_AAAJSK evans_h_Page_161.pro
3e6a0f65ad0665716f7a10088ef4229b
9d9d15a81fdaacec5f257dbbd24b1ae2ed290bbb
906634 F20101209_AAAIPI evans_h_Page_098.jp2
a952bea372b4b33b01a5968d2f02ef6d
606bab49531c8c9ba425f3a780f8298a27efcf15
55881 F20101209_AAAJSL evans_h_Page_162.pro
9570d7d3567668a554f2c714759966c3
1450eda49b746e318df1c5c1729b8c9469c1dc41
27263 F20101209_AAAJRW evans_h_Page_146.pro
52be7bbd05bfef3a3809b028f382456c
12560036feaa353e8dc99134b371999682f698df
103947 F20101209_AAAIPJ evans_h_Page_060.jp2
8650bd2553127e5f63e65460f363e951
ca922efe782767b0f01b8a839996fd3ee765e24c
95133 F20101209_AAAIOU evans_h_Page_078.jpg
f833cb19f7ef16e7150f915098c71301
c7d3e02206089a4e5ef381cac074606742dc1cd7
54144 F20101209_AAAJTA evans_h_Page_177.pro
33f7ec505ddbf4a775caae31b612d8a4
587894d797d93e56537678804d4b449d0e9813cd
57189 F20101209_AAAJSM evans_h_Page_163.pro
efc4b6319eb774993a3c20d15cd11e88
ad8f1ea37f735d7cd8f000c3e6a9f54472f20888
1456 F20101209_AAAJRX evans_h_Page_148.pro
b9f70736943ab43fa7534c817b6880c3
ddb47bcba50fa65ecde45c586f67d8ce5dba6529
55685 F20101209_AAAIPK evans_h_Page_116.pro
9c951f754734cf4da61c4eda7a268e90
3e809bf6913a87ee60a80bd6999ab58a099e4fe2
6769 F20101209_AAAIOV evans_h_Page_045thm.jpg
97b22284bc7a851613c7f523147b2c73
fcb1611f97d5d5c9486ab14af964dff7a660490c
55628 F20101209_AAAJTB evans_h_Page_178.pro
ac244562969c4ebc51409aa0a00afbf6
d04df3ab28d72f5b0760eae9c1fa388866569884
49564 F20101209_AAAJSN evans_h_Page_164.pro
c763579593fdfac7c0b3649e019b39b9
1c6475a90c3f8f9b1766f194d63ca47e34f8c3e6
20529 F20101209_AAAJRY evans_h_Page_149.pro
954316ca304b6d6c34e6a7439123e9a0
54592c05b2a2319abdab8915a5fac1f30200bf67
26665 F20101209_AAAIPL evans_h_Page_065.pro
a3f6c2f796e31f2d3f1eb4d9b386b4a0
4625c3f0e455c3e19614fce4aad81b69b7209102
34082 F20101209_AAAIOW evans_h_Page_015.QC.jpg
51f71aab063a7d59f8d53baaef31a023
fa4f4b02bc53a440406f376993d1025d5fc65881
54478 F20101209_AAAJTC evans_h_Page_179.pro
90a2f712ad356b97e6d11b1c1bdb1851
99fa239696214562399700ec77f06a671f7c3ee0
27923 F20101209_AAAJSO evans_h_Page_165.pro
5035e2f9f1a5dc94b76fa3bc78703a96
c7e0d59bf16dd497fab2d5f65e9e4a43c3febc17
21394 F20101209_AAAJRZ evans_h_Page_150.pro
c384d72eeda243ea25af5f69b649306c
3771fa3b051c7aafe709095495e4299fd9befb0b
F20101209_AAAIQA evans_h_Page_097.tif
de9f33e72a6379ed528733dd428b8c17
ffce4b8716889b2ef8ed495af1c699deb9169c15
F20101209_AAAIPM evans_h_Page_179.tif
ecdf4c6ad6d8015fb3f4c049c8dd0f3b
03fc924212a5c745d3c69788a34a014d2ed750b4
1042 F20101209_AAAIOX evans_h_Page_159.txt
366ad8baf66155129d5414de70d0e37e
191a0a61be421d96448c8ac3d3fa1850d2b87d72
36938 F20101209_AAAJTD evans_h_Page_180.pro
35655df8a2b0b5c767a527cf685f245e
1488ec59053a64de4a502efc2c31deb500004446
31595 F20101209_AAAJSP evans_h_Page_166.pro
28024323a4b6e84cac57e9d4e1728ae0
7d8812cf507b2f3bbbd5145bab4a5b7ed629c62b
52443 F20101209_AAAIQB evans_h_Page_079.pro
8bd17c88ab342bce9c856daef25cc9c3
537931660c6294641f7afadf6febf2ca43aafe2c
152383 F20101209_AAAIPN evans_h_Page_201.jp2
1357105e742789bccb145dcf4bab7b52
79a3cb92d096c4823d33c143945fb8def7619a7c
88333 F20101209_AAAIOY evans_h_Page_045.jpg
1c8f2a95a9ef3fc62af7a5a761edb464
8f41f50139bd7a0a7f3fcd20fb95483b9312b878
48444 F20101209_AAAJTE evans_h_Page_181.pro
96ae54a99f2144a1271d93a0c6b6e87e
e714c0a1af5993a6e05b4e15f984cec018248cea
38457 F20101209_AAAJSQ evans_h_Page_167.pro
786e429f5aaa317788121a1546dd89d6
6dabf66122b840f02e428f40474e05250df2fc7d
F20101209_AAAIQC evans_h_Page_188.tif
9b467b82ac97bbc3fa2d8a032df0e7c3
563203a8e4bb8390f9a3ea29195569b3fc2da568
57664 F20101209_AAAIPO evans_h_Page_041.jpg
e9361d1f42eda02a28f7dcbeff422ec0
82258bd4780c2df9342faac7fd61401f2632c059
8837 F20101209_AAAIOZ evans_h_Page_110thm.jpg
4fc07e896a50945f206449ae5faed212
b5e1428d079ba059e3bee6274cfe7214438de416
12830 F20101209_AAAJTF evans_h_Page_182.pro
06ffc084a781c99e3095fe1c6204063f
6938ba376aef56833c621c613b7793e8b6560530
27626 F20101209_AAAJSR evans_h_Page_168.pro
75c611539dc10fa375d5ee81274adcb6
842783115e876c8cc1e939b6774464d56a48c285
F20101209_AAAIQD evans_h_Page_171.tif
de3a57107fb62e8d77317f0b38639749
317ef9bd1c306c12d6254eb9555d8b2d29877faa
F20101209_AAAIPP evans_h_Page_180.tif
906cfcaf88bf364e543c37ee86202bd5
502d2c05d31ec5bccc3e626371ed1ec6a4c59dbb
19788 F20101209_AAAJTG evans_h_Page_184.pro
f4def288ac8fbf7e2476de267d750b60
34fb2085ba14457da495d6239720648e39cd0762
16926 F20101209_AAAJSS evans_h_Page_169.pro
4cdfc5cb9e23e1d5283d00898472c954
386be58be746d57e031093c47d176ea73c4af48d
F20101209_AAAIQE evans_h_Page_052.tif
6cc3c40af353d4db2c34529f1fc826de
bf74cd8ecba9edf20bb3b89fb9120eb29a8a1a46
68033 F20101209_AAAIPQ evans_h_Page_197.pro
0c4408c79098bd69b541548d46537ece
ad1de1bbc701c0d1d91d991dd16f6a0bbaa8615d
28723 F20101209_AAAJTH evans_h_Page_185.pro
5003b301b02d5bfd06fdfd73b5e0d5a1
f04d82e2f5a4cba11b7e2b3fee1b1ed8da97d683
32280 F20101209_AAAJST evans_h_Page_170.pro
948ec5e17980f28543d38c5b05549a9f
0984a1f5ac61004625a7efbdfc102da39eb24ae8
25324 F20101209_AAAIQF evans_h_Page_100.QC.jpg
9a340598d929617f1cbf52572c8514b9
f105abe31e285e53d9ad6630716b6c0998686e11
1146 F20101209_AAAIPR evans_h_Page_101.txt
dc12ec790d1e2ff55029bac00382becd
c3649072c4f88079158bcfd8c15607c71c05a814
8331 F20101209_AAAJTI evans_h_Page_186.pro
b8acf367b54d88234f07f51446af594a
7587ed6cb8fd0fc5169142511fe51476e292cc82
48887 F20101209_AAAJSU evans_h_Page_171.pro
bf0c0a379515dfdb93ed66c28a6da1bd
cbf6c5c9563259b1e5528dcdf810d76ad80ef33b
110804 F20101209_AAAIQG evans_h_Page_172.jpg
e62c29f6c63cd0b0be3e95f84549830f
a430cb3446ee63c0584abed906e2a50198098522
53271 F20101209_AAAIPS evans_h_Page_126.jpg
80d8cdc26120c18dd9a6524b32ea50a5
2ac156a6463ed5e202e91838b81032dbd9e929ba
11394 F20101209_AAAJTJ evans_h_Page_187.pro
070e20c9801a7888d651dc71ce44011c
46eb145cd5313c6fdebcdbc2e168e3603ed23e87
55152 F20101209_AAAJSV evans_h_Page_172.pro
a46dafcea2e619c2e8678604dd8755e0
8f6d76a541cfe01662dc8762c137e668d78e048e
F20101209_AAAIQH evans_h_Page_059.tif
e9272557ff82ddb2c9586b2b677a950a
4159179b9c1e55f766d06e90dd00f4a3d864c1b5
2515 F20101209_AAAIPT evans_h_Page_007.txt
3497af5bf30c6aed1c485a70e052a016
59810ce1033c0f2f530afc7bbbb5ea3be31e1106
23621 F20101209_AAAJTK evans_h_Page_188.pro
3955d33979614967a809aa67d4005b80
917784e96ac01a2425884a4103c34821adbedb6b
53359 F20101209_AAAJSW evans_h_Page_173.pro
3891772dc0ceb53183aa8a84b2df29e2
f080f8ab89060d2a303ecf2dfdef14ffd67a6ed8
17624 F20101209_AAAIQI evans_h_Page_130.pro
f5b1011ba8a4d921564b5db9a1f5e62d
e4251fa5111b5c7f4ecd345225002ddd729d8e91
82155 F20101209_AAAIPU evans_h_Page_063.jp2
f7ba715590560957aeba9b9d706d4e08
84dc86f8f1230e44d4bc20e7dc9fad52e4a31501
53915 F20101209_AAAJTL evans_h_Page_189.pro
ab76e9a905b299a2219455afcd703aa9
878147c20c2f13e97a3a387f4cb102046484cd33
32696 F20101209_AAAIQJ evans_h_Page_088.pro
831cad022b91d4f85d2573ee7d56bffd
2d118a2d16d2020e4eda56230d013ee9e208069f
108 F20101209_AAAJUA evans_h_Page_002.txt
70ab38a8343088ac2c86892d0e744e7f
d972130b53346fde5e99d72ebd3d5c570e079337
33294 F20101209_AAAJTM evans_h_Page_190.pro
07dee5a373fc7229ed984b29f0605587
f1bb7d3e4811028a83a20a1acbbfae84abc797da
54926 F20101209_AAAJSX evans_h_Page_174.pro
ca7cc26c8bbf98ef07bcb7e01d125382
49f2335eda14557aa4a2dfa7a1266e76b2a63555
818177 F20101209_AAAIQK evans_h_Page_103.jp2
d94dc219d9556c3f47ff1d1eec47b9a9
02ae85ed94672948a58032d1ad2e93d787b32186
1759 F20101209_AAAIPV evans_h_Page_090.txt
13545a85177fbbc78768c70461c355e1
94860f8df82a3402c0309f86a738bb5945d0f599
84 F20101209_AAAJUB evans_h_Page_003.txt
9d63b85bd49f9ed8fc11acba108eae56
4b412307a8cdf21205a0a79e70eb8fba3ee28efb
72715 F20101209_AAAJTN evans_h_Page_192.pro
44a4553b5f5c679289f90f72e37c084e
50c5fd8664430fdca242a5474596eb41b8f4e1dc
55873 F20101209_AAAJSY evans_h_Page_175.pro
b24b613284243f0643415cf59470c9cc
7ef1f1fa206ff57d0b49d76845a3c94f0880457f
F20101209_AAAIQL evans_h_Page_078.tif
f8075f9e8018572487edbe12fb9fb43f
c7ea01402e4d17556ed6bf33bedd6fe5262a6dc7
9054 F20101209_AAAIPW evans_h_Page_116thm.jpg
310af76ffc9b2981a3c75ba58ea212d0
6f91e278b62fb19ece145444ade06d391858a907
2099 F20101209_AAAJUC evans_h_Page_004.txt
4ba8d566f2d272307d3e899a4af40f5a
1b95ea10bf31ebedc37902ff3819f6e8ed8f9cd5
68272 F20101209_AAAJTO evans_h_Page_193.pro
ede4c736d6d0ef7e360c20592e535fde
030446c389e0354a6d9d070642e21cbca334ddcd
53918 F20101209_AAAJSZ evans_h_Page_176.pro
99de92c014982c471c0b0a598a962ba8
76bea1d0811c890f8367342ad9c6226363228bf0
49911 F20101209_AAAIQM evans_h_Page_057.pro
adfdef1af180774e8ac9d904d785674f
6c67246c53d88919dc35ece2fd86d68c726e0377
34578 F20101209_AAAIPX evans_h_Page_111.QC.jpg
2a4bc5708f2df76a8cfa7a3e2ab3abf5
6e0e3e96385d81f0b8f6c25c1eefdec0bd854936
F20101209_AAAIRA evans_h_Page_186.tif
aeeff5062c8506677f53e44a8fa80ce1
9dd96612bb7a6f213aed09f38ce47007e0e8c0bc
3519 F20101209_AAAJUD evans_h_Page_005.txt
a0a01c0ddb350760f4ec070b5d9f3028
2147593c1cbb24b1fe55537af52c63d082f548ed
67696 F20101209_AAAJTP evans_h_Page_194.pro
ecb6782affb999db9fa53addbacb324f
5b97dbe49166b354313ee1b0cd3ee89f4f5cff37
37246 F20101209_AAAIQN evans_h_Page_026.QC.jpg
0fbe8e9caa2724c3f7ac215fd744d93d
e91e3ede8d7e9ff7d6ec2533925d4eb08cdffd3d
32052 F20101209_AAAIPY evans_h_Page_028.jpg
73a186e13cc03415057c7d83cc2893ee
1e994e7370e6a663d59ae0413ffb70105d9c004e
1050 F20101209_AAAIRB evans_h_Page_047.txt
b91b3b1a1d6ddd2ad41f770b10b230f5
1c015d2e6135a3750b525ab40b1221319d6d0a8a
3489 F20101209_AAAJUE evans_h_Page_006.txt
8cf935f066a0bbc36e2faff501019579
13f297e8e58eeae74862478734501e2945939fee
64055 F20101209_AAAJTQ evans_h_Page_195.pro
c93b6e93cce5abf47d259852fbf44924
231024a656de9f25709557a0fc2842dd67b07a58
9498 F20101209_AAAIQO evans_h_Page_192thm.jpg
d15eee2989d70a9b1840ec089866bfcd
736158c2ccc79491924837a30cf2decc519e3757
1018957 F20101209_AAAIPZ evans_h_Page_124.jp2
14a20e9fabc3d5040aca50f9a53cc712
40d841a37c4d80bf4fde277c76c16462e4dbaf95
5379 F20101209_AAAIRC evans_h_Page_148thm.jpg
a589d75e721448a2fea4838b29bf802e
d588ef5dc98de79722b66862412238a1107a24dc
1586 F20101209_AAAKAA evans_h_Page_170.txt
364850457cd078806aeaa9da8d9c8d56
a73bfe449b6d7fe3174173de4480cacbba368a91
2937 F20101209_AAAJUF evans_h_Page_008.txt
b36a930fbf752ecb2a179d01ac1b4113
4723e54878291c4d0db1857dc14aeb5acf87913e
69534 F20101209_AAAJTR evans_h_Page_196.pro
ea019bbaeb894a5cfcd54aecc8eacab1
06ff4c56a08e2033f3a5cfce5ed317217425eb2e
F20101209_AAAIQP evans_h_Page_083.pro
b146f890a1348f9d5dad0bebc572277d
9cacb5856d8a862eb1483393717a90cb1f1a93da
8302 F20101209_AAAIRD evans_h_Page_080thm.jpg
dfb05b6faaff251d5a0f6318d66414a0
73faab7b05e45650a2890af3a2f64f026c65f664
2019 F20101209_AAAKAB evans_h_Page_171.txt
fed64c7e3bf1719bd8aca043b3fe825c
41c03f2df5485a9fbfdfb74b15f0c7401cd2eb85
2806 F20101209_AAAJUG evans_h_Page_009.txt
29ba46a57dd76149b4c1be71c0667dda
b6984701b091eb363f773e32489748d1fb8aa623
72343 F20101209_AAAJTS evans_h_Page_198.pro
c8acf5072fd3b340a387b1bd7c55ff3e
0b18cb2cd0e46f1815c26466949f3a9c60c76814
68780 F20101209_AAAIQQ evans_h_Page_098.jpg
cba14a559e6efc23fc84c2b033dab8d2
00a45c27ebf45371783e56a3cf8c5a31537de7a6
F20101209_AAAIRE evans_h_Page_111.tif
76e1766ee3c34c2ca90fd27ab94a7516
9fbc78217c46d3e6513cbbc0f7868552ea5769e3
F20101209_AAAKAC evans_h_Page_172.txt
4c75f09e3c2f8a851c2cb1f4535bd967
36c7a7847bc1ee50df5e3932926ce83ff226425e
2910 F20101209_AAAJUH evans_h_Page_010.txt
32f35e68b3be92735b78644cf532d517
57bd3e89486469e3adb43434451a58aa053cd8a3
67558 F20101209_AAAJTT evans_h_Page_199.pro
b73a3c191611c09c63cdfbdf8ad5e9ba
2c4e8369843a2c1e3b64d76a454af905d9c9915c
8681 F20101209_AAAIQR evans_h_Page_084thm.jpg
a1f93d0c9e337d2cd590b1cb476dad31
3a14cb307eb5bac79f4f5559dfc41a18e422e4ef
55469 F20101209_AAAIRF evans_h_Page_021.pro
7358c66f121dfdf113c7764b811432f3
405d5a39f3b9c611b93d857b64b888fd9c24fd35
2132 F20101209_AAAKAD evans_h_Page_173.txt
6dcf8ce1b568ef817e9dc0f839f89a9e
92f8246e9254a8524b5599e35fe978558598f101
1194 F20101209_AAAJUI evans_h_Page_011.txt
edb1a177a273243c21f0973224596a13
3f4be66c2c82328cdad9417687412821cf96515a
69720 F20101209_AAAJTU evans_h_Page_200.pro
77008eb3925b9d3aa989f57e91071c16
7876163c4fa5a77aad7ac2ddd589b34f7fbb806f
63535 F20101209_AAAIQS evans_h_Page_191.pro
22cc3df17d4aeaf85abe0f5ed82174fe
6993e5e6c83fab13f354efd6440a1b224105715c
235082 F20101209_AAAIRG evans_h_Page_186.jp2
6ba6f4cd66c9b8b78ca5218f89fef66f
76b84c808f6e71f3c1a59352857a54c792f3556b
1970 F20101209_AAAJUJ evans_h_Page_012.txt
38914af7c4a6268fe3ffc948402e1c9b
b29199cb433e9a7c1fc5f819d7cee66195a1d9d7
74696 F20101209_AAAJTV evans_h_Page_201.pro
08b9c8b78213c93b8c72400cacc85fbd
f8fdf3ec6c202fdc40a99a293f0d32080f0c1661
2236 F20101209_AAAIQT evans_h_Page_024.txt
3b053ace04052c8e9822565cbce9cc4c
1b5e599d6024b136b980797a0243f85d86e4a447
1002 F20101209_AAAIRH evans_h_Page_149.txt
ffa0fff4c4499b0b77b2e639f4c7eb7e
65a5c3be4d17ef222e3d358c2a14bc43bc432039
2160 F20101209_AAAKAE evans_h_Page_174.txt
6f0a6f17d7805e9840e135c7c95c9178
412b8b099e7deb1bf5dc8ab63edb1a8fb5c5fe80
1106 F20101209_AAAJUK evans_h_Page_013.txt
f531e2156a75f3f8629cd5e4273a05c3
c2cc3477fcf42aa8cfd1b7e14f7cb487bc13e3e2
63836 F20101209_AAAJTW evans_h_Page_202.pro
8a166917add8fe9c202546bae739ae87
c10f692e8f18e910d231822f058587dde16ad5a3
F20101209_AAAIQU evans_h_Page_055.tif
a4681726f9f340609ab0d6167d055bdc
1ff70aa0e09c7fc3012596ba4bfd0031a39d01dd
233405 F20101209_AAAIRI UFE0017566_00001.mets FULL
081e963332743b83d9425e7d71c4a38c
4d0bdb078242f307acc70e9288fa5b8ba37f7142
2217 F20101209_AAAKAF evans_h_Page_175.txt
e884d5022c55cb73616a59cc3063e74e
861f62a606287573352caacf3bf271d16eacdb23
2039 F20101209_AAAJUL evans_h_Page_014.txt
c8f2b5d1260bd0387003bb3dd4b06f0d
27d535d1d37677fe637e683ca95b057222208408
18518 F20101209_AAAJTX evans_h_Page_203.pro
760e9ac33e2a97603de795fa63c1bffa
6671b417a7dd199d84d9412b09c28131ad46f914
2213 F20101209_AAAIQV evans_h_Page_051.txt
d6e51b2c362aeff829f82a40ce629603
d37c5fd3617cec5f91b8d9dca36b99d648c5ba27
2116 F20101209_AAAKAG evans_h_Page_176.txt
bd240c63ab78b70b495b71dc8c5eabd0
c1c092592003edf5549b9955af17aaf1d5c3f5f6
2251 F20101209_AAAJVA evans_h_Page_031.txt
877734a79a516d1a056dd6a78eb57a32
6b3e6b36cb42e4ca4a058590acf327e8d80c495f
F20101209_AAAJUM evans_h_Page_016.txt
ab4630ea4de8624bfedb71ecc617dc78
e3526980e45f4cfb1f510369367cda59e1093ea9
2127 F20101209_AAAKAH evans_h_Page_177.txt
a879501b7f775c6c92c829fa8a5bab44
d4ce8978e4662d1da1edf11a52ecbf6ad50d394f
175 F20101209_AAAJVB evans_h_Page_032.txt
062ae79a5d4e184ede10ee538a97aac3
eb1c77d5f4cb93d27f538b1c12664301cdfc8f7f
598 F20101209_AAAJUN evans_h_Page_017.txt
8dee46e9782de2058c07d79323c04900
83a14653c6a2c56ea86b89ba32f752b7c5e5c0fd
37915 F20101209_AAAJTY evans_h_Page_204.pro
ddae39874da32e1b8f4660c27e0fc138
d405398b95e6797ce129bfa55ca57495eef018a4
36444 F20101209_AAAIQW evans_h_Page_172.QC.jpg
a7820476cd6786f32cfdf334ef0912f1
d278c93df9b20f5f727b518085fc99145bd67b4b
4713 F20101209_AAAIRL evans_h_Page_002.jpg
28b89f9519d6b1bd99f591cf288ce3ad
777311a0048b5ea3ae054ef1511e76811a708430
2224 F20101209_AAAKAI evans_h_Page_178.txt
13fc23acc1577cd713426935c9d68054
56ac3e91241ca1afe9a55571ef3a59feb995ee7d
1770 F20101209_AAAJVC evans_h_Page_033.txt
dce6fd993b9c844f3f503e5a338f42c4
8afedea04ea40f741b762212a269741d6179a95d
2093 F20101209_AAAJUO evans_h_Page_018.txt
62c34d3655d30753c8e9b1eb6b1ee408
39a1e85f03a8e0c6c5c4912b4e5f8d48fc79a458
477 F20101209_AAAJTZ evans_h_Page_001.txt
3700a1aa77a95457cb65376f46b51ea3
c7acabeff4cf7b7caf9ce0db39c850147618fff1
14707 F20101209_AAAIQX evans_h_Page_182.QC.jpg
91deaeafd2e6b5b23ef982cc93cd4f89
901642655a9f96eeb3b10201d9a352f06495a2ea
33924 F20101209_AAAISA evans_h_Page_017.jpg
b8668a5174e1186a676eeda21358d604
f549cde13709886481c52e374825030c608f6945
3488 F20101209_AAAIRM evans_h_Page_003.jpg
069c6c70b8117bf30069780f06b03d73
37545e6da5c1f5d52f2896a8a8269811799f20de
1469 F20101209_AAAKAJ evans_h_Page_180.txt
5b27a62c7cc9d60e6f81971fc2097540
b74f14185c9c6acd497388d229c034b7b2aed45c
943 F20101209_AAAJVD evans_h_Page_034.txt
0c1f6548471d48455ec134a44119369a
ac98e0712aa5b016b2efa2e6268e386a1a0b0c11
2206 F20101209_AAAJUP evans_h_Page_019.txt
d3dcbd937512485c1db0cc844b5e5e04
8d286beb8ccc71098cb000910bd26dab6c2b6218
84460 F20101209_AAAIQY evans_h_Page_147.jp2
5daf4d0bd23e2af1bdd00541801c7c72
c0346b43e7692d5564c73a589098dacc3d68f588
108269 F20101209_AAAISB evans_h_Page_018.jpg
dfbe36c5035ad6f5054af339c0f0df65
d2ec1d556b282398c4f3eadf9afe5045a661198d
110887 F20101209_AAAIRN evans_h_Page_004.jpg
3d370427b0fb45556820884f29f02c80
58144770b5348f2dc5fcf5014cb5d9a702a29099
2229 F20101209_AAAKAK evans_h_Page_181.txt
d13d5cc9b9269219061bd056a3a1daec
5b0c5c5268b58af2221482cb6ee0291f8a286a87
1495 F20101209_AAAJVE evans_h_Page_035.txt
7f3b24c302235150f85c767331bf410d
01f5f369d3d7b0ace5afde816b7858f286196599
2097 F20101209_AAAJUQ evans_h_Page_020.txt
084bcd69565db3e1dca55081c9de4eda
3f71d018cd7be0a06dcb5eada492ee37cf39e57c
43095 F20101209_AAAIQZ evans_h_Page_203.jpg
5d224ee5ef1877752f7e29a4ca64669b
a9dc0bbc4e2e8ad7924158e64bf1f9314a05bbd5
112427 F20101209_AAAISC evans_h_Page_019.jpg
7bf6b37dec01a832e6f2ed059a8c597f
ca4fdca95788cfec67059a32c9c859ad1e0dd975
116603 F20101209_AAAIRO evans_h_Page_005.jpg
d12a9a9962a3fbf713db6512bc917cc2
7c2df787b40bf33a925c21f1d7d910298c957cb2
2724 F20101209_AAAKBA evans_h_Page_199.txt
374cc97ec2ed66ed24b3488ae30f006c
2a23255f3f5b6a86073e452259f2799f02e62d1c
770 F20101209_AAAKAL evans_h_Page_182.txt
7ad1ddcd0b839d0a5ea9aed27885388d
c92e075e438563cb132cf988ac21aa5285b00478
984 F20101209_AAAJVF evans_h_Page_036.txt
12d0553f0f8e40e34fa86858018b2f70
6067c111cce8cc95c74fa03787c5350bc70a11fc
2179 F20101209_AAAJUR evans_h_Page_021.txt
c2fe7a9c706ef868b1bc23aa420d2872
79f6cde5abf4da6582308899361049b435f2c167
107063 F20101209_AAAISD evans_h_Page_020.jpg
65564709aef3c79abc46c74cf765953a
d15440290d132ce6b7f8ca5d567e2a94ffbf1477
133579 F20101209_AAAIRP evans_h_Page_006.jpg
d694dc079b66fab5dd5c65b4124afa1d
c330a69a715a9a11fa941141ab8fa94dddef64fe
2816 F20101209_AAAKBB evans_h_Page_200.txt
3b58a2209cedf27c4be071e4fcd10cc6
ccb09f59a30ae516dbfe3b00caf486ce99dec4ce
1290 F20101209_AAAKAM evans_h_Page_183.txt
a9848410a5fc19134764ab2014b592b0
acb1cea06531e3836c248948ab7c42be4095716e
849 F20101209_AAAJVG evans_h_Page_037.txt
18219fb40e091a8e867424eba365c6fb
87abfd2e0dbaf7b1df403b3ff58d4573b409b709
2135 F20101209_AAAJUS evans_h_Page_022.txt
ce952e6c6c4a8777f6fff71e2e9eb2e9
c2ddbc4f9b5b01ea64b9e2b2d7afd7a27a998e61
112485 F20101209_AAAISE evans_h_Page_021.jpg
57540a30c0a6d7118df06b3fd6d375b3
aae8340c979e000789f2fe6f4112308fd3cb1fc8
98261 F20101209_AAAIRQ evans_h_Page_007.jpg
ac69dcea6d231fa908cb9776cbb22cce
b854a5e0e9bb520462938335895b543c1bf24b48
3006 F20101209_AAAKBC evans_h_Page_201.txt
a850c58575c01407b0fda52567f0be27
8009905c47c97efea7f6f724697756d8648a295b
1012 F20101209_AAAKAN evans_h_Page_184.txt
cb600bc523b63f75b6b5e5d4158b4601
3fab526014a709931c3e9773404ff1570ed745ed
1419 F20101209_AAAJVH evans_h_Page_038.txt
b01f4a4d2a41448ee564798f0aa530ae
252e5295e63d50b014886c93a40cc591f6aec6d9
2214 F20101209_AAAJUT evans_h_Page_023.txt
7d6264cd65b75d7059b537de569ddeda
5b93d3339786b61001d6ea244ed067129d7288e0
109484 F20101209_AAAISF evans_h_Page_022.jpg
ae1f62f85388fb0da110427faeaa5237
66aaadd39d596b707c3eb435852780653cd9a910
122874 F20101209_AAAIRR evans_h_Page_008.jpg
f2ec3a44ad694f6874d4fadf1b88405a
7d68a2b4f29d0590b23c75d5e2d1e226b1560a24
2571 F20101209_AAAKBD evans_h_Page_202.txt
a20b26260851221a3162d0e5a52699b8
ed16f8fd691392b99fa7af31db2eb3634a27c923
1260 F20101209_AAAKAO evans_h_Page_185.txt
840cd05b47744354ecef62cf92c822b4
2dc44a4d6b5640489da13160258fb5e7aa40c764
815 F20101209_AAAJVI evans_h_Page_039.txt
fd68d7e467253ca847a767a6790b4023
ac88bf56ebd09959aa532d72c2b9f85fd36700ec
2201 F20101209_AAAJUU evans_h_Page_025.txt
ed088ece9b274f6cd077e302d68ef8ef
cad11d5e195acd4165ad5e5b133134615e3944da
110820 F20101209_AAAISG evans_h_Page_023.jpg
76fcca4b09a67b1795ff0f5d2e0fad66
317a01f64f2c7bfb143367d55b157ed5bc72922d
127272 F20101209_AAAIRS evans_h_Page_009.jpg
14378f4f19aeb1cc8615fed35cb5836a
b0c46ecc1514c540ac81d8151f40e130f577d97c
758 F20101209_AAAKBE evans_h_Page_203.txt
f2a6dc2eb631c277c3146ba93bd1653c
6c6abeff61c97c0c25c0881a4d523901a66387ee
1450 F20101209_AAAKAP evans_h_Page_188.txt
ba3f36e53208c2914100cdea21f04f75
f6fff8eee1be29ad483d09c15ba4c1e8b1ea771c
2431 F20101209_AAAJVJ evans_h_Page_040.txt
2ae66121a5aa5ef4d217a58225e150f0
b4cdbb3c6661e3b71dbd688b485d55b3b1b1b09d
2202 F20101209_AAAJUV evans_h_Page_026.txt
56e4fdf7790e6ffbe8185909f06b1b85
4d049ff3e9412c58e70b1f8a860e419e7646f560
112693 F20101209_AAAISH evans_h_Page_024.jpg
aa02fb8d2b5a2791bf86580fdf9b13ed
42a351049f9bede7b93529b376a754309149ad71
128773 F20101209_AAAIRT evans_h_Page_010.jpg
40ee111685f398910c6771de759397b5
da2898dcbcfb544dc9806f6bde347f7de77bab96
2188 F20101209_AAAKAQ evans_h_Page_189.txt
15e09c070cc54315640da387009ca279
2fa336df19403eb8d1676fb14b8bf08f9bce056b
1225 F20101209_AAAJVK evans_h_Page_041.txt
7af5410b231287b564d062f3da3298a4
ce37fbe4ecfc6faa466352a9abe660c3e3fbd77c
1335 F20101209_AAAJUW evans_h_Page_027.txt
b0f67bd3c32e07c16d8ea7e88d8c1571
cf3a8e77ac015b5c966e2124ec727f7c7efcfc8b
113015 F20101209_AAAISI evans_h_Page_025.jpg
259e409f00d7882535403a05adb0de77
9ef55645adb9dcc2236e682b3fbf4d6d7be0b399
61030 F20101209_AAAIRU evans_h_Page_011.jpg
7fc8475cdefd5a1647513cc3b0278c43
71d9b21fdf46131e052c17dc34d697158f14d57f
1539 F20101209_AAAKBF evans_h_Page_204.txt
83bac58e199d977e5cf8bac73adfa176
eb7f97ff9201649def0974da9df4c20b69c7a211
1324 F20101209_AAAKAR evans_h_Page_190.txt
339c697716cca7e4b557e1c351cd1d7e
a3811f866c016b124a0c06262f4fdaeeb4857d1a
2496 F20101209_AAAJVL evans_h_Page_042.txt
5dcb9cc0a9bd4e593071ea492db99a96
403e54856fee5fd5cb9c87f053c12a67d9f11d56
675 F20101209_AAAJUX evans_h_Page_028.txt
e5ff9db952ee0309035e538a788c9946
eec3f3157d93a25cee34e74b3afb572be539b623
114233 F20101209_AAAISJ evans_h_Page_026.jpg
0420634b051e639215e0e3b24a5240d2
562e7f84ea224c213237fbc867adbc3dff8def5e
91463 F20101209_AAAIRV evans_h_Page_012.jpg
86b8ab1c47d02044f083ccdd542a9ae1
07a899693ee703f3635a76b133845439951cdb65
1986 F20101209_AAAKBG evans_h_Page_001thm.jpg
62819ad201f2a915d54a8343e685511b
4567b10f2f93f3438c6a7b2223598162146dc425
2577 F20101209_AAAKAS evans_h_Page_191.txt
aa1a96db9bd114c2c248969ad94f91b4
18282cb27d2212105bb81d0e0ef27a2bd6b50c36
2727 F20101209_AAAJWA evans_h_Page_060.txt
efe56c7fb6d43aed544c4c633dd7b283
2409738cb6bbdd0beade91281d83d17612c63267
2366 F20101209_AAAJVM evans_h_Page_043.txt
95a0bedcb451db40921899db361e66cb
2d7b74f379f8008238b7bb09e8aac2b27703cf97
4087 F20101209_AAAJUY evans_h_Page_029.txt
a65fd3871083985cc8af73611b78b3d9
f06706400bc3dce9a0e97bc359a0ee3b2c1a26fd
68711 F20101209_AAAISK evans_h_Page_027.jpg
81776c94047088b275bfda3057c00ad5
a2d381d207bc6f319fc065f817e2e7bd887d6a59
58248 F20101209_AAAIRW evans_h_Page_013.jpg
8fc28d633f94f38ce2b49ad02f6ec743
37d4053bba5a2f855db774dd55f0ad7c2bbd01ac
17422968 F20101209_AAAKBH evans_h.pdf
ff6c0d94dde0cf6a3a0b9d48ad0718c7
c0c6980d1918bd8fabbf5fa841cdf4b2b061d5bf
2929 F20101209_AAAKAT evans_h_Page_192.txt
850af4e159819589c7f7fedf2d20fef1
b12ba39e46a610b56ddd9fde9b4db90f9f1b050f
2517 F20101209_AAAJWB evans_h_Page_061.txt
3276b25feb8d6593bbab822589210a0e
f071c2bb9c5861ad67ca4c331be3464b259c76f3
2193 F20101209_AAAJVN evans_h_Page_044.txt
2f0b2a0801654be0a335b641768d97e8
749f11a60943fb905220249a5fbde5f604f7e24b
74975 F20101209_AAAISL evans_h_Page_029.jpg
71bb8937f79a515abb0fc3a4b202189f
a75648d31aea8cb2c76d49934c09d0aae038f47a
33443 F20101209_AAAKBI evans_h_Page_082.QC.jpg
84c41fc60b18e1c4ba683ee52f07a82f
d119d747fdea069102c1afd17ec15ac77bfa775d
2744 F20101209_AAAKAU evans_h_Page_193.txt
df35f117eabba160102f7a1c58ffba4a
1ed421d84c3fdf81bfdb627dbda8f5b98a1fd6be
3114 F20101209_AAAJWC evans_h_Page_062.txt
88d9800ff5040aeb8f7193295a5395f4
3c5e6683c8843d2f35e434fe85dcf04b56eaa7ef
2010 F20101209_AAAJVO evans_h_Page_045.txt
fe836e9027d346958836d4dd2e220c73
745ff1d2e0b5192f2586e2b7436f75e3cdac4382
3179 F20101209_AAAJUZ evans_h_Page_030.txt
39c788bf20f9582a4f83bba81dedab89
96b166d146af170fd7ca936224f34c84795fea3d
73501 F20101209_AAAITA evans_h_Page_047.jpg
07d868c7b100b783d2107ad779e44485
532007cff91e9d4c325b4004f83d0b64c0cbec07
98968 F20101209_AAAISM evans_h_Page_030.jpg
a25d0d9a2a95cf87ef0a9a9efea7eaab
d1a10ed9becdacf211c1134ef5406a1c4c7ba232
100681 F20101209_AAAIRX evans_h_Page_014.jpg
1e90c7b6f63d86cd537402c60636ca26
0a8d81a850798d7929e22477c3df23f32b1bf5b4
8779 F20101209_AAAKBJ evans_h_Page_173thm.jpg
256ac4dc1b04464230301eddf39f1228
1aa217504b677c0a0b2b44d84979a93a3a9aaeca
2748 F20101209_AAAKAV evans_h_Page_194.txt
2efb4ad8f1ba7121cb163669c30cb283
8d151000dabd4b209de4a84958c561df8b488208
1830 F20101209_AAAJWD evans_h_Page_063.txt
f0c95e94b53f0f5bb0e5f8c2069cbb8b
ac89f4d4691edce5b5ab9a74c6d6c55edda8add6
1269 F20101209_AAAJVP evans_h_Page_046.txt
180a8940a4f0508a9079d265a04bba4b
03e7830f69be699d6dc9aa1e7be8c154bb2faa24
114421 F20101209_AAAITB evans_h_Page_048.jpg
c8b28bc2f5f1ac6975b41c150ab098de
a260e6ac43c761db7a3714be503341dc124d6ec7
81985 F20101209_AAAISN evans_h_Page_031.jpg
63ebee5066308fd25079560254779bcd
19742ea4b2dd03ab35e899ae431921068207e164
104181 F20101209_AAAIRY evans_h_Page_015.jpg
af7ea96ef4c2802b60f0ae66199e317b
5a4d67bd57e5fadb43829cc5935ed200ca7026c4
9075 F20101209_AAAKBK evans_h_Page_163thm.jpg
12564fe0e1ed6c85e03a0571316c4df1
70e9e8d4179c10de17422150d793ab4369fe8f81
2591 F20101209_AAAKAW evans_h_Page_195.txt
d01f006fe16fafc46b628b79303bed66
ba97c8b7016d4ebf3d926267a5a61975fd5ee40b
F20101209_AAAJWE evans_h_Page_064.txt
2a843178e15a97eb22ecc7b456cb58ac
cb1215d8d3c731629eff4a894eb452de08a2bc5c
2210 F20101209_AAAJVQ evans_h_Page_048.txt
32d0bb26dad655c8fd7a61c07471f292
4c271509e29a85457c8e8a04e1265eadf5d66529
112647 F20101209_AAAITC evans_h_Page_049.jpg
8d6423752894ad83c3e3591999bc0d57
97fe09db5f404edb672e0f379d320af4b72193b1
43665 F20101209_AAAISO evans_h_Page_032.jpg
68f53ae0cbfbe6af2747b0ae62c1684c
62ef45cb05b7fe58d8f0369f48d2676b77de21b5
110676 F20101209_AAAIRZ evans_h_Page_016.jpg
c7f29346b26c223a61cf1cdfc8caaa17
0af7a7a32fb7fc9ec16b992453a324acb84d86ee
27592 F20101209_AAAKCA evans_h_Page_007.QC.jpg
f247b9ada1f79bc9aacbf022340b6b3e
0a6510d83d8ba6f57c7feb20b9c83c0189229f9f
4691 F20101209_AAAKBL evans_h_Page_181thm.jpg
63f96b17fd14af3290f98593922c5afe
6267bdb5310ba02658a5a97a4bd2ddbeb373c642
2824 F20101209_AAAKAX evans_h_Page_196.txt
a00f70630270c230da4945ce01da6e01
01c1e609cc0aab83c4304575d9104d366924a13f
F20101209_AAAJWF evans_h_Page_065.txt
3771a61362523cfc0ac9750bd696086e
f21d2de1f02f292473ab2ca9b5e3763209a4a092
1949 F20101209_AAAJVR evans_h_Page_050.txt
bf8d705a31518f9286bd9267e24c4361
64d7c5c230dec67c9dd1d4e38849c1e11b6af8e7
112255 F20101209_AAAITD evans_h_Page_051.jpg
f091031cef6713fc26fbce4be578f260
c55095ee6748b3c31561d0d78a1ce879cbcf9dd6
75973 F20101209_AAAISP evans_h_Page_033.jpg
af85e5cd80c2c86607901232f83b18bf
2214aa70166329cca8c1745859f23c26b56e8b6d
37766 F20101209_AAAKCB evans_h_Page_048.QC.jpg
37d58f4c5fd0063473ddbf7e5d92c4c8
80803d16548d01d777e781f31c03102bb1bd3376
8664 F20101209_AAAKBM evans_h_Page_016thm.jpg
23b4ce028cceb4a46a10e0af85709530
5cd86fc19b70a909927b0b295523d48ed2f33dc9
2750 F20101209_AAAKAY evans_h_Page_197.txt
b2b6ea69f78c71809986ebaa8d9670f2
ac5a3be74108fc964a3d418d8819f038780fd2f8
1323 F20101209_AAAJWG evans_h_Page_066.txt
1add9216d0323a518a24a6d4e8ca7e6a
3100bc97eafdb81d9250e308c132888dfc2467a2
2094 F20101209_AAAJVS evans_h_Page_052.txt
95c001d8444c960dfa0d3946954eda65
94570ef9f7782eff3007d21b977ab03e7e558a8a
108803 F20101209_AAAITE evans_h_Page_052.jpg
c52cdb3c6a13aed9d122ecd639f81b23
1fe23e215152146998783323ae24a9762a546265
76189 F20101209_AAAISQ evans_h_Page_034.jpg
eab280729a232c0449a584728b026427
fe07655057ef3d0f62a2afc0ee813055c89d725d
9060 F20101209_AAAKCC evans_h_Page_195thm.jpg
6ef466896cffd14dc5bd21da022c8287
4cf409fb10679fd4a23f5cbc4529fb03946f3725
5563 F20101209_AAAKBN evans_h_Page_147thm.jpg
9350cebc94b8a5b4980401e99e515fbe
09fab220fda369556ddae4337d9c391603b8daa8
2905 F20101209_AAAKAZ evans_h_Page_198.txt
a3c26bb69e01aa98c4775c4f72dbfe9e
d2144e099841743651be2e59d88f70889beb79b4
1205 F20101209_AAAJWH evans_h_Page_067.txt
eeef2fdd3f3411e5b79d9eaa8fd7e7a1
7e81454a118b453159b2b603c5f3c13821004b31
2204 F20101209_AAAJVT evans_h_Page_053.txt
500c4d7ce9d86384110f23933dbb9331
20d0c93faa4dfdc0ef9b53315a4e3497013116cb
81389 F20101209_AAAISR evans_h_Page_035.jpg
ccfee1f020c26646bda6d285e42a19ee
63ea3e2ac5da1f37d37a2b76d784b1bf0ab5bfd8
111325 F20101209_AAAITF evans_h_Page_053.jpg
bcef36bfc6c68f2954ccd518c2c65eb1
5dea5824c1bb1e15f8affbb5f55f7ee8f7647125
8225 F20101209_AAAKCD evans_h_Page_008thm.jpg
0798f7488d9819628edec11bd093b35e
1de15148d0cd99f6432fd33f944f7f12a1c770e4
8869 F20101209_AAAKBO evans_h_Page_136thm.jpg
73b00a6f1482058cbb52563f543810c8
643dc9865a6b4a55348fcd981f850326ee231122
2016 F20101209_AAAJWI evans_h_Page_068.txt
51463e485797ef0de89da541dc9b4eb0
c718947730dad3973bf60154dcb63be68664968f
2168 F20101209_AAAJVU evans_h_Page_054.txt
1d3b358e932202698a18a03faf584cf7
a08d5903c888e7ac523c6ea40df841cd6b25dcb4
49835 F20101209_AAAISS evans_h_Page_036.jpg
8757ec0f8c53a21a7b8587835561532c
5a483b91ae645b9b73147ba2cddbecc74372efcc
114411 F20101209_AAAITG evans_h_Page_054.jpg
fd5986eabaa4dabf54a5fb2bce8f1375
5a246421814e3ab25538f8d0755ae992a98e46bd
23572 F20101209_AAAKCE evans_h_Page_147.QC.jpg
f6c604870e05d07f6abefa3238e8495b
7a520d7fa0149d60f9d4d179e1f3553f100030bb
36957 F20101209_AAAKBP evans_h_Page_114.QC.jpg
1049f5d7c24fa47c3947fd13359fb829
6b0b0f3f8387bbb4a3c3e0d27846f5f7cc654be4
813 F20101209_AAAJWJ evans_h_Page_069.txt
428a4126781335d25d7bf9c907f27bd5
5ab76b094ded4210f3aa8eba0485d7d39b6b6893
2175 F20101209_AAAJVV evans_h_Page_055.txt
7745a921cc9c8686e8bfceb3106ed32a
a28959cca27d471337680d2cf0ab379b2eb32a9c
83134 F20101209_AAAIST evans_h_Page_037.jpg
012adad9689c6f037caa6e8360f9ad19
dcefa0a07b304a798ebbf35a280e1cb47dfbd5c0
114438 F20101209_AAAITH evans_h_Page_055.jpg
a9da6b24b7838cb0657ecc8b28c14b6f
405f3419bdbd97c5ef15b2417037099508bb8834
35566 F20101209_AAAKCF evans_h_Page_109.QC.jpg
a0e309ec4332f26d4a43373b17812eaa
24f8d5e29064e1adb2715cc775b178e4af5832f1
26698 F20101209_AAAKBQ evans_h_Page_094.QC.jpg
2bd12641efb40c455874aeedfa01dd91
b52f064a01e41458ef503d540710e45bfbfff5ac
727 F20101209_AAAJWK evans_h_Page_070.txt
981882dc6f74e44855dcc2de102c5f36
d32637f90a3233d84bc9b0a8cae5de0f14501457
2038 F20101209_AAAJVW evans_h_Page_056.txt
3e9fac095877ec3a3b9eec0aa6d284df
a1b700b7f4d89e0d368cd16d75cbc02df7a5aaea
77588 F20101209_AAAISU evans_h_Page_038.jpg
903731c229c8d5845a0d01485a3b864c
c0758d328cc66be3c5a558e8a3274b2d3d70d8da
105755 F20101209_AAAITI evans_h_Page_056.jpg
bf186bff4c7df45b99249e4d0864991f
41ef2d247f39862bf6a1c0b60c652c88524d7dd6
9056 F20101209_AAAKBR evans_h_Page_139thm.jpg
382edcfb1e3c4a25b26670b117ef7326
cbb895df52778f4a4cfd843d66efd75abf1361aa
3404 F20101209_AAAJWL evans_h_Page_071.txt
77f9a52a636eeab7fab4f73689e8c1ec
268f600c7b5c18010d4c3ea96b4e9dfcd58167d3
1975 F20101209_AAAJVX evans_h_Page_057.txt
2dfee2d3efce311bb45082a49e6db5b8
5df77e91a0808dfe3bac317fc4c331edae867042
69607 F20101209_AAAISV evans_h_Page_039.jpg
b4338aada34ed88ea64d151b98b68c2e
c03b077278ef8b228f6e1b7d51edacc1b08e925f
101370 F20101209_AAAITJ evans_h_Page_057.jpg
1973b5d49bd60c09399a45fe55e2dab4
a529be40b64a71b2f3f14af792625aba708a220c
7067 F20101209_AAAKCG evans_h_Page_100thm.jpg
839ff4a39e548a2bf5d888d0e575868d
f4ff8c6c0d9fed389b647485fb19599e5ea4e20c
5505 F20101209_AAAKBS evans_h_Page_041thm.jpg
d721c6990003bca20d53759f0c21c8ce
3e115348f693aa4e5efd72f7b5864f72818fabb8
2270 F20101209_AAAJXA evans_h_Page_087.txt
2bfdfc0205d0b92d940ae2da515517ed
6379afb7575ed783ac9cace5b49c7c5de13224e7
1927 F20101209_AAAJWM evans_h_Page_072.txt
bdd2968071184ae8330116b9940c26f7
6114d01bc0528a5d8f4c963390d6c064db6102d4
1790 F20101209_AAAJVY evans_h_Page_058.txt
bcf4d22c0368d43c87fcab3663e0725c
8cffe8422c1debfa2db671bfba1f78370e66d8f1
76379 F20101209_AAAISW evans_h_Page_040.jpg
e31f448cbd864af0f48998035de26908
9f27732813a8e4116bf9ae5544f60227fd1518d3
89962 F20101209_AAAITK evans_h_Page_058.jpg
b022f3e92abbce82820e2ed67327f774
a9b8f4b8b0d8cfa47d7754330fbed568799307c5
9061 F20101209_AAAKCH evans_h_Page_087thm.jpg
16ebe31da58b5dccaed4fe1ec1d18a7d
05b50b44ae2f814723467f4fa69d3381caa88e6c
8740 F20101209_AAAKBT evans_h_Page_054thm.jpg
cef3b0204583a6af2f57cf20a71c0885
1e0c04ee8e04f13eb1368f44854e6dd67c8c4b23
1301 F20101209_AAAJXB evans_h_Page_088.txt
77424ed3ea8b4f892363cf08fc369ef6
4beb3ad39723374b804094f7f1ded9233c809e9a
1633 F20101209_AAAJWN evans_h_Page_073.txt
4d1c9c9b0d6c4b87560e340c368a8c56
9e814aa99f2963524183bc65fe6a3707684b5492
1969 F20101209_AAAJVZ evans_h_Page_059.txt
b28d4a83dbdb0b30812947413e5fbc64
b0ed0584af6775a2c7e994847a5c4354fde115ac
116079 F20101209_AAAISX evans_h_Page_042.jpg
4be47104727667c6d9ef2b0e1d46b738
480ad210ffc5274d31b7fca722d572d1d578e904
63243 F20101209_AAAITL evans_h_Page_059.jpg
457643ba819f5edb619a879a7730e0d7
7b1516cd50dd9dc3c2bdfc24c2d14cf09d7cc9e8
9018 F20101209_AAAKCI evans_h_Page_141thm.jpg
b801ef90d8db52e594faf7603c4302b2
d28d29580e894c5ff8a0e71920fbbed2c2308d94
9325 F20101209_AAAKBU evans_h_Page_196thm.jpg
47dff70d378451e6de8ff19360ad866f
35b3ffb6ecab68dcc020e8498e482345838a3a8d
386 F20101209_AAAJXC evans_h_Page_089.txt
a0404457b899f27862bad6f935fe0267
88d48eaddd181cd88cf797b99aa0a99fc0287d06
1912 F20101209_AAAJWO evans_h_Page_074.txt
6058fe9763ebe26cd1cb69bf9961b390
815e7ba5e4a168b35211bcd9b9a03ac131ae8d8f
113498 F20101209_AAAIUA evans_h_Page_075.jpg
1a953e9befef993870300b76dd18c1a4
e3513baa607b70537b631bbc8bbc1067f5360c6d
92872 F20101209_AAAITM evans_h_Page_060.jpg
9bdb516b8067c3cda02e651cd90ae3ce
ab6b7290b614f4f6ebd507f13960f9b5d4b9e2c2
18597 F20101209_AAAKCJ evans_h_Page_059.QC.jpg
a7a551b69277e812bd5a394831dd8896
1a9861af62142e7f04fafd9114c4a0ffa0d4a928
13353 F20101209_AAAKBV evans_h_Page_160.QC.jpg
6ce286a66ca48f6b8978f21f7ea555b9
8e5913c4c803de89582632f674ae7ca6b945a109
1125 F20101209_AAAJXD evans_h_Page_091.txt
d3dd5e6f383c6524b327270ee53ae85f
a8ec3f07b5a208a134d89716c66a8f93f3b383bf
2163 F20101209_AAAJWP evans_h_Page_075.txt
8b3b6c7d6178b9d1870d624cf5730499
0eb51d6041838eef95bcc50a932ee096156a55d1
107623 F20101209_AAAISY evans_h_Page_043.jpg
c8550abb4ede2230955d9cdb6b8b7afb
d890067ac63299e03fdeb58575de392fee52571b
115846 F20101209_AAAIUB evans_h_Page_076.jpg
c27e22f906ff3c3186094e3248b84628
7c31b515ec1b1a38ee0488da342f386dc519dfab
90772 F20101209_AAAITN evans_h_Page_061.jpg
f28af3c91b2aa4790335200fd7dcd7e4
91860a9b344a41cda5cde4ccae207bc05f43bcd9
37033 F20101209_AAAKCK evans_h_Page_024.QC.jpg
18018cc4db1b5dc93009c8f76c8fafb3
bc068dad05678c181dd933940890d9b166b10018
6688 F20101209_AAAKBW evans_h_Page_030thm.jpg
a77c955340ed5d9744e26366fb325396
477b60a34f76c61ae2300d088060067ff8d4718e
909 F20101209_AAAJXE evans_h_Page_092.txt
30e30fad9d83a8a20e0d80e3cd0d981a
388f5645b7b5cfc8f3e8b88816424dd622e6dad4
2247 F20101209_AAAJWQ evans_h_Page_076.txt
a4414d5a17e6cc2a5b42d8a047d9772b
b23d661a92205cf44df8882ca34fa51afb222ae1
107626 F20101209_AAAISZ evans_h_Page_044.jpg
0ce6779e9492563869f2e78edfc1d553
e65be7efcec640a5f59c3f9d1b934facdd8846db
110566 F20101209_AAAIUC evans_h_Page_077.jpg
842c73cc2ed85f6f580cd7b0783e7ee4
078ff72eaaeb0feda455b9231dd4c3da3c42bd59
95321 F20101209_AAAITO evans_h_Page_062.jpg
fd0cb1a63d6837fc633dda156a9d9b2a
3007533e4c2fc79d06a63628590257915e154ce0
33977 F20101209_AAAKDA evans_h_Page_150.QC.jpg
77587b09abfcce564825931a2c5a7936
e4417bd3b40a85dd52f9565c3d37562ad0026c2e
37023 F20101209_AAAKCL evans_h_Page_051.QC.jpg
eaf3cd9c15737f6aecaef5e33b5cc3ce
e2e6e62ba5886ca5c25cdce2c867a798d7c06dc1
18523 F20101209_AAAKBX evans_h_Page_092.QC.jpg
cbae6f530bde5193767632f6f6f4d239
efeacb79ea4f780d66beae53cfa2ea7002daddbb
2245 F20101209_AAAJXF evans_h_Page_093.txt
0c73618862b09207d362ddd847ac51c4
e7fe4f909ca2aad1784e94d44507b897ffd4178f
2111 F20101209_AAAJWR evans_h_Page_077.txt
55e02c402d979e14673980e36ac1910d
7e3cb2f6c89a1dc2ea13bdb86d88f8bff9decbe7
101474 F20101209_AAAIUD evans_h_Page_080.jpg
7ac036963f00eceaf71b109b62e54f7f
7f897b4f645fa59d1d86534fba85bf621b9c7322
70139 F20101209_AAAITP evans_h_Page_063.jpg
c69727f5f37c2f65e862c270011417d9
d317f8367d23da20e936915a7c8de1ce825b6d8a
23511 F20101209_AAAKDB evans_h_Page_073.QC.jpg
7f01103583f0dbf98e6e95fb1acd9d63
075e7a798db6d7e3a6187acd8e933db270d4e8fb
9116 F20101209_AAAKCM evans_h_Page_104.QC.jpg
2134108fa9476ae0057158b35ea90741
24a4977f75ab14dc90a3582d82ca25adced84947
37642 F20101209_AAAKBY evans_h_Page_115.QC.jpg
ef5e6a7979b24255e893fe09288ae24c
1c554da90bb6a66a66e515eae26a734f07976c67
1771 F20101209_AAAJXG evans_h_Page_094.txt
ff184ba0658c0a31584cfdae7b042619
f1238c9b197b4c2ed857fbcd40464f45cff55902
1824 F20101209_AAAJWS evans_h_Page_078.txt
2b6d1db2d256d123e4dd5caba8009461
88a82dbfc40487f13c3ee05c397d3b99e9ca03e7
104709 F20101209_AAAIUE evans_h_Page_081.jpg
b2ed6240975ce9fe8370faa69f37d27f
ee2f5471ced6cf4a0f20271c7b3bfa47097639f4
51204 F20101209_AAAITQ evans_h_Page_064.jpg
1b51a9262c949ebc1d060ccdea46ee62
dccb2a27291d68e0c02a00bc0410fe8c2505d82f
8661 F20101209_AAAKDC evans_h_Page_082thm.jpg
e28f34e858d58fccb76ff160bee678a8
15204359ddd0e3156f542988d3c23acb6f47767a
34748 F20101209_AAAKCN evans_h_Page_086.QC.jpg
65ecf9408bea6daef934f9692e9f1fd0
a1c1c575b11463fd1b402f93ca4483be14e89297
4353 F20101209_AAAKBZ evans_h_Page_184thm.jpg
1f39e2d6ed0b4f0e9e5a6efe35060e68
56b500434b21c29550ad9a68f74f6cd3e2a69ac3
948 F20101209_AAAJXH evans_h_Page_095.txt
5ec951be3a60f02376b00a5aa482f2b6
b46f54365520a7d3d63c09b9643b8b532da57b54
2062 F20101209_AAAJWT evans_h_Page_079.txt
25441b0ee77f41bc43452ab42780cd7c
b6d7f209231321910106bc8d530dc617b7020ac3
755275 F20101209_AAAJAA evans_h_Page_039.jp2
b66dea4056df3c6c3afe111bdc7f3d96
41db0304e4b3d2eceb33756772d94a4227ca12f5
104431 F20101209_AAAIUF evans_h_Page_082.jpg
9b0069f638ad40b7c87c708b8cea05bb
fba4c3611f118a06a538b38596c9e9c74b38211f
80009 F20101209_AAAITR evans_h_Page_065.jpg
55ac6e9ebf728fa9e1e355ebd7bfb7df
2c41818538937fd4c4effae474383841c2d79e2f
7889 F20101209_AAAKDD evans_h_Page_001.QC.jpg
f2b1318dbcb770cfd854120ab6de54cd
1ff8b9f11cc7d21b64a41627ed9ccb2176e4d719
6415 F20101209_AAAKCO evans_h_Page_046thm.jpg
57465db692527cf4ddef0791d6c950f5
f968d4f24e5c1efcf14068daf985f15de71e8824
1783 F20101209_AAAJXI evans_h_Page_096.txt
910a3097b317c07f2dbe515621b2e718
3a397c42d0e28666762ef021979f6e8409091806
1990 F20101209_AAAJWU evans_h_Page_080.txt
38c1012bdd11e93f61e33b007587344a
ef819524e6a67a5227e04fd9d0dd3f3b7874ac3e
818101 F20101209_AAAJAB evans_h_Page_040.jp2
a874f16607b61006dc1a88207184a5e4
7e249765ad0ae7d206e6645928d734665f57f665
111416 F20101209_AAAIUG evans_h_Page_084.jpg
fa4c048f272d4b97c5e513781a1b94ae
a54aaac4785c93bf2d92383d4785f0b52880033f
79699 F20101209_AAAITS evans_h_Page_066.jpg
b5ac2a3cba9a50f2a365d77a5c55b7a5
c669516acc2101da8eafae54404e54df660df327
8545 F20101209_AAAKDE evans_h_Page_138thm.jpg
5dd95d6961ef42ad87c499e2e17a133b
11b633ac4c78cc3a99001a253343612da85421c3
9205 F20101209_AAAKCP evans_h_Page_085thm.jpg
5041b8dfe6d410bf5cc07c4b2b91da55
0122da5e34160ffefba4092343b20df901ae371f
1111 F20101209_AAAJXJ evans_h_Page_097.txt
19b91b26f5ceee4bd47afbcc0d8667a5
f07a5d1925685cc30978c259b37b082a3b4abeec
2089 F20101209_AAAJWV evans_h_Page_081.txt
802a684264a9b36afa763627fbc8a6f1
fa63c66ac574090f30d4c23884c7db6587681dfd
552674 F20101209_AAAJAC evans_h_Page_041.jp2
2cf7b51768979fbbc9d9396be0542699
32a1992b8b20877579cd984d53224e23dffc193b
112796 F20101209_AAAIUH evans_h_Page_085.jpg
51152ac7bc663b109a8cca3daf64d588
ed486062d08245d0155081f32037135df7cee034
71972 F20101209_AAAITT evans_h_Page_067.jpg
834f4e48f888423aa9f49de701ed1326
a8283905fb88aab8c77dbee2566364b0e02b4a06
4758 F20101209_AAAKDF evans_h_Page_064thm.jpg
c0dbd6843c0980e9ebe65dfa24ff1d11
494bdb6770965442656d03b2a28f547b2d5903b0
20935 F20101209_AAAKCQ evans_h_Page_072.QC.jpg
5d17b6162392e3638c109318e846d0b3
0a3f59b22480c44a6f0e54784c000100b9edc954
573 F20101209_AAAJXK evans_h_Page_098.txt
a17864204a3543e9eb5cee67fea26d44
2864454e64e0fab412fdb0ead6dd50f3d6c49534
2002 F20101209_AAAJWW evans_h_Page_082.txt
f06b8f723fa78c665b795f0497f4cf72
9b3f9cf0f967317fda71a5ab0cee810351eb3339
107537 F20101209_AAAIUI evans_h_Page_086.jpg
bbc071af814199f488b6bfccc9565a25
4c6fd325e066cdc0c7aa07e15860f561566aef22
39454 F20101209_AAAITU evans_h_Page_069.jpg
905d8cad7b81d6f01c97cd7218f81d10
76a1d3adaa6dfd97db17cf1af9cd4639b87fae70
1051965 F20101209_AAAJAD evans_h_Page_042.jp2
e34a6dcef139f20fe2800cd46a9cb452
cad44a5f98c52d655381d226921b881ce0f081e4
7216 F20101209_AAAKDG evans_h_Page_135thm.jpg
a54f269c732dce4f6ea5f9a574fa41ce
3391edca3badf075f04c0a309e7da35c6f615dd6
30882 F20101209_AAAKCR evans_h_Page_185.QC.jpg
e9554e29a9b86995c400f17c94850457
9bdf2b78d0e0eee9030282e0b99a15e6cfa962af
885 F20101209_AAAJXL evans_h_Page_099.txt
d1bd08ebc6fb6a95b9037d403fdf4876
929845441d4fe9cc73a9b02ec83e775e56351a98
2181 F20101209_AAAJWX evans_h_Page_083.txt
cae5cfc9c54a3bbd0da1c60c3c43b50a
3b182bfa831ad78120d328c0f1dff0a32585573c
114906 F20101209_AAAIUJ evans_h_Page_087.jpg
f6e147cdd6a95f302b43aca1896e2379
db7de02c76aa379d85d7c567a4e2888050f61f78
112049 F20101209_AAAITV evans_h_Page_070.jpg
ee10d30f3098e01bab7efd8917d1bbc0
9a05d10bd1c9f5e22bf6a4c951bc2661715359a2
1051970 F20101209_AAAJAE evans_h_Page_043.jp2
9f54779b09110f967ffd6107380bc9a8
958cd219cc3c1d4586a8456fb247f4fb4128bed8
6520 F20101209_AAAKCS evans_h_Page_102thm.jpg
6683897aa1b6c9cf6092d4c0dd52bae2
81210f2c74de213048b601784551b6cf8703c23d
2194 F20101209_AAAJYA evans_h_Page_116.txt
2a8cc2c7104fbb3a5bec00fb73fc9a91
9efe17551ec4d46b0b56b1c05d9cd08c4b68db64
1114 F20101209_AAAJXM evans_h_Page_100.txt
39af34c74fc1bf4e287c642f3cfc0921
1532ba7c53021a4676aab2c3640ebcec99135d4a
2128 F20101209_AAAJWY evans_h_Page_085.txt
e7fbb30e1125af64823220adc9157b25
c46485c1bf1a92b09553af3aee0c7ff80cfe9801
67529 F20101209_AAAIUK evans_h_Page_088.jpg
061eaf8316af9309e11ddb745bc6f92f
c75a0e9b46a93a7333145d9759cd895f92b6ddc3
87842 F20101209_AAAITW evans_h_Page_071.jpg
ae5cc585c2ead85fbe245b7d50581c25
bf6d8ca746ead2a674a49b414d46f049b1bb0cd0
9669 F20101209_AAAKDH evans_h_Page_201thm.jpg
5f407530be1c7427afe2c0b31d233a1f
a09d5c4b6ca66971ac2234427a70281d265b2b0e
37614 F20101209_AAAKCT evans_h_Page_075.QC.jpg
70e807abf0b35ba6632cd5ba5cd755a2
0bcc798fbe07665ad6b5855a4c85424aa71c0c52
2209 F20101209_AAAJYB evans_h_Page_117.txt
f3a6afab878798ef1f146bbb904461dc
7cbf01338770aad5a65f4907be62be837776a10c
1038 F20101209_AAAJXN evans_h_Page_103.txt
7e5d4f563d1869176d3126a4283c2308
e150ff26e425620125e2c575df9efd01bb34b43f
2084 F20101209_AAAJWZ evans_h_Page_086.txt
81ae784d52cf55f08c3588d25ad13466
4d34a3c30db6ecc5884afb8f5e24d2e96184e665
18684 F20101209_AAAIUL evans_h_Page_089.jpg
a016fb809934f3ce3ef70c6f164ffc55
828ca73c6bb6b2dbacc5acc4781cc3f2be7e890a
70923 F20101209_AAAITX evans_h_Page_072.jpg
0da604469ed01053a9dfbb56d449843d
979ff626bf2bcd443017e046485c07c5de67ff0e
1051984 F20101209_AAAJAF evans_h_Page_044.jp2
82b3500a7348f7f901255eb360f2fcd4
8df88b75ec2c0d0261f1af0e7be3522599f702ee
8969 F20101209_AAAKDI evans_h_Page_178thm.jpg
4aeee056315fd92b0a39fc3bb6922458
7f9abc615c3f4f46e5040be4c1795dd99378b613
27892 F20101209_AAAKCU evans_h_Page_155.QC.jpg
acdc496830f235498a184810a6ddc30b
4854eb79614a9f97d1da3e7c0fb2bf1513a0d7f2
2104 F20101209_AAAJYC evans_h_Page_118.txt
8abdf167f5fa1426a1b4af90b1bf849b
0b44bc35da84ca0bd7750be833bfd697e8fc8e3d
602 F20101209_AAAJXO evans_h_Page_104.txt
5cd0a81b71e1a77af92eb8adfcfe705f
8f03e60a491bf650b2bdedf268b6d8af4d0ff3ae
108106 F20101209_AAAIVA evans_h_Page_107.jpg
6013b27c4dc47f62a7479e6cd8cde993
e64f682d80b44af4699e759a6b09aeb76b0f9167
59946 F20101209_AAAIUM evans_h_Page_090.jpg
fe9e7be479776076e16c6c2cce5422fc
efd8f5303ec85910b76b92642699f7e86ba786a6
73528 F20101209_AAAITY evans_h_Page_073.jpg
cb58554bee1e03a5b49b52825d7c6969
459e99b9398fc1022e7b602ee2f4a9ece13a3ca0
1051977 F20101209_AAAJAG evans_h_Page_045.jp2
90726cc40a795d3165a937d37f318297
9377257a670eec1b566b2de46e04c74ccc42d6b5
8560 F20101209_AAAKDJ evans_h_Page_171thm.jpg
c542266238d082e85b0abf67fe603a9e
167c0cf361200266fa6ba2c28cca008a6da76f08
8903 F20101209_AAAKCV evans_h_Page_024thm.jpg
88a0885d51c3d25089ea46413d943a89
d810a84d9211132426e99ac9c3d088aef5f5b2c1
1977 F20101209_AAAJYD evans_h_Page_119.txt
ec726f7fc3914ebcd510961d5a57295d
3cc1f1bb0ed05b2893fdbc8b1f25d181c597b7e8
2169 F20101209_AAAJXP evans_h_Page_105.txt
9ac3b846e77f15802a047d891d954d18
d63a10c74e79862db40ffc1bf157b9110cb8240e
113911 F20101209_AAAIVB evans_h_Page_108.jpg
318c493e7bb65919e3287305f8e5e180
ad7b7cfeaaa62eb013f7cc758049ce3e4b10e2db
43215 F20101209_AAAIUN evans_h_Page_091.jpg
82ca38f18c067ef39e477d19d0bb37ca
04581e3dbb0baeeb38fe3c8b43d197a95fd67775
1051973 F20101209_AAAJAH evans_h_Page_046.jp2
8a7550d29f264508cf51e36a1dab6a07
c3c4c98f78649f9e279c6fe78f8777715b6667dd
19180 F20101209_AAAKDK evans_h_Page_103.QC.jpg
7e33228c67cbb2e5b54f549c53a36d44
6fc1fdab1f024530eff72d58f8dd54f0bb612c30
4221 F20101209_AAAKCW evans_h_Page_123thm.jpg
9337570e9478c985b9b95cd57547433a
6c6515e903803b34c52670106a47e2041c21a998
1010 F20101209_AAAJYE evans_h_Page_120.txt
3a52cee47a1e498709398cb17aa94279
6c1c58889bb36a20475ea0b90d65b871e195f893
2143 F20101209_AAAJXQ evans_h_Page_106.txt
eac414622ba2d51331531079286145b8
4ee86cdcb4abb98ba01bda74fbcddf8c67902d2d
109802 F20101209_AAAIVC evans_h_Page_109.jpg
abf192390bc203164dcd267024b3dbbe
6dc092c4ee317560eed310363a2ae9b02a899179
62439 F20101209_AAAIUO evans_h_Page_092.jpg
32d68d5016175f063d7b1c0927b2561b
7d832e3c92bfdf3fffbbbea79f224b8ba0403c23
104976 F20101209_AAAITZ evans_h_Page_074.jpg
d6d99d7fd9c034ee7f7357a5c1348811
16b36e08d9e292c6b1cd85fe05ec6e7eef792a50
830061 F20101209_AAAJAI evans_h_Page_047.jp2
d7fbc0c23eeff1b19767aa7da70c4e3b
927ca72fcaef086dae82ecb1caf5ec960fcb97ba
29926 F20101209_AAAKEA evans_h_Page_096.QC.jpg
43a949d3423ba0462d653e1bca8d14d8
107bac83ea9210f32c1b24be71e2b751c28cf70c
27247 F20101209_AAAKDL evans_h_Page_030.QC.jpg
a0b9edea0ad7373a923a05c287da4291
46337a9cf4abf4acd26f5bd43407d6a92c00e3be
14740 F20101209_AAAKCX evans_h_Page_134.QC.jpg
0aa882021bfd45079561062d421a941b
c8c88ffce8d913a7350ebec02a18da7534bae7e3
750 F20101209_AAAJYF evans_h_Page_121.txt
449c30e9c6a212a211df3aa03d950000
11b359e0260eeb3939e8967c65329c9ede5e5ca9
2075 F20101209_AAAJXR evans_h_Page_107.txt
bb95c97f860b2879cf647888e5e84ab5
b6a91aa12b3729fc659554f380246c47110cd5ec
111137 F20101209_AAAIVD evans_h_Page_110.jpg
41428ae69c09b117f4fdf7a6eb2a0af5
f3261540944f5bdb34498d489d3b50ff27e409ce
87444 F20101209_AAAIUP evans_h_Page_093.jpg
fd647e84304424d0361e0355c39ba13f
01d87a33b98c0fd2cfc18d660346bafd641f6a20
120255 F20101209_AAAJAJ evans_h_Page_048.jp2
df340b4d17b3863e2efdccfdab176aad
6655ac53a016108eacebf573f0c3ba36940bd2f3
6227 F20101209_AAAKEB evans_h_Page_156thm.jpg
8fbaf9fa96cdde10bb7008ac3ebe4ac3
faf340797d6d131bcde9168a317a77f2c2994bfe
8799 F20101209_AAAKDM evans_h_Page_177thm.jpg
96006ab6af94580e362d442ee552d266
5b957500e0b13ff6f961ee200b8eb88dc53d6e52
35885 F20101209_AAAKCY evans_h_Page_189.QC.jpg
e441c47fbd31de337ec0c33607bb4fb1
e50ca76ea84d70111daefa44d0092e01527798b4
952 F20101209_AAAJYG evans_h_Page_122.txt
13d30acd87f28a61eb49e53dafaac54a
76a03e794caeb990fb02c20d18ea8e3d29bf1b3a
F20101209_AAAJXS evans_h_Page_108.txt
839f35d919b5cedf57575d8f45153abb
78f69ce39470444f768cb84e8a253400289589ac
104791 F20101209_AAAIVE evans_h_Page_111.jpg
5edc04089b2ea92614429d6284ea6320
798879adc76b54672605c0f3879b555676daad92
92355 F20101209_AAAIUQ evans_h_Page_094.jpg
33ae74ff55eeee1fb5232563283f0556
e76770d133f15086494a5db8e70af0f731591ade
120974 F20101209_AAAJAK evans_h_Page_049.jp2
571ab5043c0c7ad433beaa3af7412a12
8057c899c661861fc9eae6a53a1004b73f073929
4671 F20101209_AAAKEC evans_h_Page_165thm.jpg
1fd20b2dd92fb37af87d9868f4d54bc1
47d70597fb5400a5dbd1554180daacba22f2a558
24734 F20101209_AAAKDN evans_h_Page_157.QC.jpg
2fac505fac25ee532bf217be302300d2
d2745ef12383c552b64942221196036f563c5b1a
4625 F20101209_AAAKCZ evans_h_Page_182thm.jpg
e97b8df24655d7a06ece4ba7e5385d12
c2795c0511ac71e6def7588c9045efa92d1687ad
971 F20101209_AAAJYH evans_h_Page_123.txt
600fe2f78c264a922d6da3f2e355dcc0
55a08541ce1ef1595b4049a9751967c9f435f839
2098 F20101209_AAAJXT evans_h_Page_109.txt
f202c860796e0c39b2ea810199060708
39537acf343d27c63234c89a2aa407b361308a1f
110035 F20101209_AAAIVF evans_h_Page_112.jpg
d6037cbc9adb86c3ce4bfd56be899e60
8496264e8ffc9e15b3b568868e557c73d412a069
90103 F20101209_AAAIUR evans_h_Page_095.jpg
7b6ac4096a90e50dc8dfd3d2d0a4fcf8
2b3be5ac764fb8a4f6925a18e0022b76e92f4a35
758739 F20101209_AAAJBA evans_h_Page_067.jp2
fb4a23e3859b725ac3bbf2701092f4ba
b744154ebf40226686a707013079f9e9d9b4559f
108368 F20101209_AAAJAL evans_h_Page_050.jp2
898e8a4ae30cea5f1a77c67f5738f773
8caa9627d3c3739f7bc308c22312a0b232ab6472
7936 F20101209_AAAKED evans_h_Page_050thm.jpg
653ea72dc33bc15236b2212406ec22fb
3dd3f9dc6effcc6c6f149e8818b0d04cca280dcf
9293 F20101209_AAAKDO evans_h_Page_202thm.jpg
e8e95c71a658e6011fc8d1f7c5e8ba74
88e15d1bc133459c9970c41e91aeda75fac217c9
1780 F20101209_AAAJYI evans_h_Page_124.txt
12ce4537f1929c8f59d2b80cb5ccd28b
7b52e34fb25988824f556b4f88c4a8c90f7a85c9
2146 F20101209_AAAJXU evans_h_Page_110.txt
79dd1d5a3d04d3f89ecf9fbf1a5c101d
202fa5a56f7fed5e408c25e840cff9b1fc8aa58d
109540 F20101209_AAAIVG evans_h_Page_113.jpg
175205baa7d762ea606a0cb2fa841e26
6cf44d948b5edff399c3435f783dd0c8ee171934
101962 F20101209_AAAIUS evans_h_Page_096.jpg
e797654696b4ee670d83af8898ea8dd8
ff7b2b7d09721e9dcb0a05c0069f26701a40e0b4
448453 F20101209_AAAJBB evans_h_Page_068.jp2
90ae167022cfa7e4cad3cd3ed2f8dc2d
394865e2cfdafd72bb95433e638d37e74700163c
120251 F20101209_AAAJAM evans_h_Page_051.jp2
547ce36987752a44575c606f03df8228
1f56ed24da508eb11608bf8f20a820a3abd91da9
6552 F20101209_AAAKEE evans_h_Page_204thm.jpg
fc0fb846d5044cb0f077c16cebdd6152
ec1d7185cd117d3e00aca2930324f612ffe20fe6
5153 F20101209_AAAKDP evans_h_Page_187thm.jpg
f9a51d42fc1f44cd264879f71a090dff
9f3fd98dd77eb1e084f67870c33d03c260fbd8b1
276 F20101209_AAAJYJ evans_h_Page_125.txt
e3bcc6827e2d2e7d5f0c59b1c93da30a
0b5623786b956e792669e2ed836345ced8d25ff3
2034 F20101209_AAAJXV evans_h_Page_111.txt
86cdc4f669da88a6c1c1f6ad2026259e
07856efafb496937f707a4cb722d59f73df02609
111401 F20101209_AAAIVH evans_h_Page_114.jpg
dbe047b194b684f26c1e9821f9b9096f
5df13b1c68f206caaf9f668de8ec4d0ab1eac812
63436 F20101209_AAAIUT evans_h_Page_097.jpg
f8b3b0a131ff9cc42fd2bfd3b5c19946
2fa28e9cfb9967aa54396dad343970340d673f4f
371057 F20101209_AAAJBC evans_h_Page_069.jp2
a99685aad7b909ccf1bbccef28874e09
fbb0a38ffbda2b769d324c814d6ab2ff0106f2de
114849 F20101209_AAAJAN evans_h_Page_052.jp2
e629d8086ba6372ec5b32bb323816e9e
17954824ac734520cd07674fb0f337d8d5c5629b
5429 F20101209_AAAKEF evans_h_Page_088thm.jpg
f4ffbc51623639523046c00c14df43ea
149ffb48974c0fc9b57e7727d2d0cb5c79221c73
8905 F20101209_AAAKDQ evans_h_Page_105thm.jpg
9c285b4e77ebc33577d6e939803e52d1
0f146423fc6dfe5786ca2cbe86304ac9ddfc968b
757 F20101209_AAAJYK evans_h_Page_126.txt
57395b6994124379349aeb6b7e15c3f8
f54e8657ee669adf11781b41e72a29886a59b290
2124 F20101209_AAAJXW evans_h_Page_112.txt
cc6dd757131e1b717a5f0b096ac1ec46
836c31aa72d5350d8c89316a279a4c02ce9545ad
111900 F20101209_AAAIVI evans_h_Page_115.jpg
5ba9cb163efda273aba5729200bba543
06141e09dc62bedfd3c7b00e2f451dc6a27496d4
77176 F20101209_AAAIUU evans_h_Page_100.jpg
5cc2a7347ad522a00452445512d379ef
3c9c1d6d1dae1ae5503726b2be0ee7f2205368b6
1051876 F20101209_AAAJBD evans_h_Page_070.jp2
258a3811cead670dfa2f8ad40cfb4c32
b20fd92ccd60f499f15ea0abc8992f50496fd10d
118216 F20101209_AAAJAO evans_h_Page_053.jp2
fb3750998125c1f43c877e3bd4c02056
7a0cf2e1b1d3fbcb902cfd717fd8e1d474c4d519
8259 F20101209_AAAKEG evans_h_Page_042thm.jpg
fe219532ccee8ca95e0bee0e0646c5d4
1b2891bf8824b5d2e5c6d532c53b6d6ca5a9400d
8669 F20101209_AAAKDR evans_h_Page_186.QC.jpg
c3450e28e13644597f09c41ad71857f3
be91e5a661ce82bd2292f96c6798f63f54b9e46e
1131 F20101209_AAAJYL evans_h_Page_127.txt
3dc649f31575ccffb077c4c7e974f758
b64dbc33fb09b775a01439c3d26b7dfa6669e444
2195 F20101209_AAAJXX evans_h_Page_113.txt
b6c7dd3d2d77c2e59f9002103a5163d3
fa0e222b507b56203eea088c6195ccaae4e787e3
113074 F20101209_AAAIVJ evans_h_Page_116.jpg
81450be401152f9edf1e8b565fa9b85b
cadd09c5032f87e40834e8d32c1cd7ed7e41494d
89267 F20101209_AAAIUV evans_h_Page_101.jpg
ca9984ca5d4715076e3751679cbb9a54
edb2bcc7735c9c2922861ff5493575eb35754670
917971 F20101209_AAAJBE evans_h_Page_071.jp2
d9624aca351c3495470aae15475853f6
a7fc13043453804b2f59507626eb41ee9128233e
120947 F20101209_AAAJAP evans_h_Page_054.jp2
0a8fed4c71126a3425ed6fc62900f782
de7bc060a9bef725fce960657fa442d49503d92c
6052 F20101209_AAAKEH evans_h_Page_145.QC.jpg
bbdc927a3b1d873d5566f6fd1d0bae5a
703b8e109c758bf160b98f4dda10d821b8f6ed06
7393 F20101209_AAAKDS evans_h_Page_012thm.jpg
8fc1d0b34793e74826efda53ad5e7ff4
23207cf28926139e141ec42ef5a5cbba07147891
2259 F20101209_AAAJZA evans_h_Page_142.txt
53d995e0e6a49d727587e4e25585d93b
b18c5a13d6e997ce8e365d076476d8987effcd48
667 F20101209_AAAJYM evans_h_Page_128.txt
154477ef74e55456b880afbebf973791
12f25fc7a692699ad31b0893f33e2beb2c7e0c91
2156 F20101209_AAAJXY evans_h_Page_114.txt
8f437fe15b7c7843cba3edefae594dab
0c11f7980c5c1ad0fceadd3e2592f9d03a823f45
113278 F20101209_AAAIVK evans_h_Page_117.jpg
b850458f09b37796e351c8d95ac19d3f
3a2710d7c4048dda822d5c42f282caf569f2fe57
74834 F20101209_AAAIUW evans_h_Page_102.jpg
de65ce6e9e20da80eb5529bd9666336b
64f57d9d3f741458b019921b70a7994e1163db8e
787172 F20101209_AAAJBF evans_h_Page_072.jp2
ff464038ef3d9f9571cfb26940c86e42
91abb5387b8bcfeec807efdbc892312cef4067ee
122349 F20101209_AAAJAQ evans_h_Page_055.jp2
743522cc0135e99c829aaa367f29cabf
b71af21ef15b498c634d2e59fcfe903d873f08c2
6098 F20101209_AAAKDT evans_h_Page_065thm.jpg
0525a83dbcae23a1723dafa45d715481
3972b73236a59b69cef501fbaa8520aa1513ce51
F20101209_AAAJZB evans_h_Page_143.txt
f134c8dd82e61c10681b6aa4cb51ea65
add7cc58ddb596efe3f7a495b19dc902e15baa9a
1230 F20101209_AAAJYN evans_h_Page_129.txt
a89044cd16785fe3e69f63c395c62804
0ea701ec60c4213c36556b5155a9389b3dac3845
2154 F20101209_AAAJXZ evans_h_Page_115.txt
130c71bf43e6cca4ebec4861bb8fb64a
b3bbba1a1e2551b55494d3b16440e175fe573275
107149 F20101209_AAAIVL evans_h_Page_118.jpg
e9cdef5af1cb0ada3794d1b0e5c41d13
04d756dd9ca6d8eef0e9268db73c042fc79cd563
58700 F20101209_AAAIUX evans_h_Page_103.jpg
bc34c95ec8f09daf8fba977e0453d8f8
cc34ed5db77fc773c7893245edab3e4fdbdadcc2
113275 F20101209_AAAJAR evans_h_Page_056.jp2
42c179c218328009b697718f6d2a0579
4c9f41426e96def5d9abacc7fc0c4477e333eb87
9608 F20101209_AAAKEI evans_h_Page_198thm.jpg
15196232278289b6f8805a23ba6f296b
b1a98bf442805b12069ce475192db5193a12bb08
21379 F20101209_AAAKDU evans_h_Page_039.QC.jpg
d6c72443a8ce2eb8b8b895cb63a8294a
e09be78cf39cf9d06775181bcbccfe4e17c4e5ef
F20101209_AAAJZC evans_h_Page_144.txt
3ecc471897693d1b6ccfa699cf7331c6
dd2ed3cbc26619bf9592dd4923e1561fdacb47d1
1181 F20101209_AAAJYO evans_h_Page_130.txt
f7f1790343f2a6c9af121b759f357954
1272c5b1639598d6e88ae22bb89e9d0247c055f9
103729 F20101209_AAAIVM evans_h_Page_119.jpg
3499b03201e9a447688657ffd79cfcc8
28266f7b6806559e3a560633a6e599f7a2cbb7a4
113080 F20101209_AAAIUY evans_h_Page_105.jpg
a5a774842c95717d44e06bc22bc22d22
1738179d982647c4e4be484e2b93933ee9e1cb1c
702546 F20101209_AAAJBG evans_h_Page_073.jp2
318e2f9e824a587e75c44312e5adc729
ae7e428e4a6d5fff8d42ab0ca6648261c5648ce8
48003 F20101209_AAAIWA evans_h_Page_134.jpg
d62b88fc63b7f2ee8c5ddc19978e0c9f
226bb33bbc42128c817efdcf373ce19242feff72
108598 F20101209_AAAJAS evans_h_Page_057.jp2
778fe58c2326abe6223586d9df46c58b
3eee4ecd76c89751c3e1b1fc7e993cb70184c0c9
6591 F20101209_AAAKEJ evans_h_Page_033thm.jpg
8eea5ed6259303e0a7c168d265330670
ba20ac0fd0382b17dd74e8d1a304978dd70f258d
F20101209_AAAKDV evans_h_Page_162.QC.jpg
8b1dcbd98e556318944baad079d33784
8db15f516819fde01fc12d135bcd4fca8ba1ab80
267 F20101209_AAAJZD evans_h_Page_145.txt
24596b661f4bb740561957ca6fe10e5c
a4e324e53c75a77cbf8a2de9069c5c0a581cc9ea
1867 F20101209_AAAJYP evans_h_Page_131.txt
e8efbcb60bf3e699e3803f3173c73bc5
0567c9f44d6b4971d39030cfeb792d7151afe9da
55855 F20101209_AAAIVN evans_h_Page_120.jpg
f64e1b9ab22e79d428f27f81fe96c6ab
8c617f8f2de4fe577dbc3b880e4bf8234466c1fc
113336 F20101209_AAAIUZ evans_h_Page_106.jpg
918c87c98ed35a69de96f224994313c8
47cb0f1cb90bd02ca152e5693f225e2c00e14d2c
1051983 F20101209_AAAJBH evans_h_Page_074.jp2
aeecb2984b1dca5af0c0bc14b72dd4a2
dfc743eaa354ff0021b2da2e6b5b7b6993e42263
74989 F20101209_AAAIWB evans_h_Page_135.jpg
87c12f252b58100282bdb4a62f3c1fd5
f93d237644adc8600d8d653cc8869a703a671e6e
96593 F20101209_AAAJAT evans_h_Page_058.jp2
4e44780b05b985b143732ff8027c2224
c6ca81ca41690e2e28738b6cd30a37ba61c1cf2b
9063 F20101209_AAAKEK evans_h_Page_048thm.jpg
d8e58d103e5afb23bd203c33d2cc26b4
7616e6b19ebc805ba745dd2702bc54b77259f2a7
24687 F20101209_AAAKDW evans_h_Page_135.QC.jpg
1d1c2536b3088cfe3b9f67cb1a5c8b78
d2b6dd8d0aca3fa1e32c02d15e0c0d27b119b8f1
1216 F20101209_AAAJZE evans_h_Page_146.txt
62bf46c598642e0eb9833bd8340069fc
57d66ebbd9ae973d6db83d0c3858efc6da8722b6
1065 F20101209_AAAJYQ evans_h_Page_132.txt
d2fcbfd3c077170746749b35d4b8ffcb
0f44ea06a3777be5c0ee66af53d3e7dc7ee63503
83825 F20101209_AAAIVO evans_h_Page_121.jpg
9cf66bd684b006eb1481a7124d278e91
136e14c5f2a50e631c7601ddab9d9246905b44ed
117934 F20101209_AAAJBI evans_h_Page_075.jp2
4b3b6f65b1eec0689b4fb60145e09ea6
caf184deb6b1f71123a3f86fba459a401d4bbab7
109248 F20101209_AAAIWC evans_h_Page_136.jpg
fca5556a715d88743f0c96d9f5b63acb
df5e4d49af67bffe028b6db92077cf8a76deb254
70913 F20101209_AAAJAU evans_h_Page_059.jp2
ed5a9231518e7663f67a8be8bfe94104
d6c10a67fb8421289fabe69d8ba9bc54c9223f6d
8688 F20101209_AAAKFA evans_h_Page_109thm.jpg
73dae7d7c1f486983e48bb979fe24a58
6c480555fb5b333f771f8e67c9bc5475ee837069
31846 F20101209_AAAKEL evans_h_Page_043.QC.jpg
7882bb9c557b7fad664c1304b6abd482
005aceb68cb0a03038d5908b6872b31b138ca7da
F20101209_AAAKDX evans_h_Page_018.QC.jpg
6692a7bfcd8087536451e4d940839d7a
4e8870d9adc7c227f09b9d645b6b82d176106a8b
1876 F20101209_AAAJZF evans_h_Page_147.txt
33a6bfbc26889fbdee8f37041908d790
0bf62a7f5fc1c763747198b15da4a5c038a78839
940 F20101209_AAAJYR evans_h_Page_133.txt
ca528862dad77a61469af5851675b44d
b0bd8d2b78f7cfb687e0950e8eb4b7dbe326da64
45742 F20101209_AAAIVP evans_h_Page_122.jpg
59157826cfbeee9a454343f8a8c90e23
9c7cb47373b56004bd97a7d27e4a5293b2685520
122213 F20101209_AAAJBJ evans_h_Page_076.jp2
db8d5593ea7c893b5334e9f6289618dd
367a9bc20250912af3cbddadf9feb8c1ea15ef83
104114 F20101209_AAAIWD evans_h_Page_137.jpg
dff5fbccd87dccdff3ca973c9a3747e6
391279bb6b6dee3d989c7cee7f1641b1a7a08f39
97944 F20101209_AAAJAV evans_h_Page_061.jp2
6df67a85a55c3aec78e8ef99897b3491
6ad784d853125bfbbe026d6a0dab96e63391fbf5
8878 F20101209_AAAKFB evans_h_Page_112thm.jpg
abbf086fa04bce802186841cbaefb30c
befa6e2fae91f367c3b0aee752c327c4c7a0b284
34648 F20101209_AAAKEM evans_h_Page_171.QC.jpg
f4b53b68ca36e259e942139123a9b516
3aaa8857d8da0359722d48c4f6e42418717b1db7
8840 F20101209_AAAKDY evans_h_Page_118thm.jpg
da8ecb20a552563fc256c8467ecdf115
6267e23ec06df8e440cdd4a9d97e96d5883067d0
118 F20101209_AAAJZG evans_h_Page_148.txt
a524ad48a0caa3c46d4c4c60a4f8f385
ea1b835ef64f4c14ebdf415e5e882b64a6296921
752 F20101209_AAAJYS evans_h_Page_134.txt
f89fc458ecf83bd0f0107f2a24e5267b
79c9480f697f2bc9dd5f6f2fe2b7a637d10b310f
44500 F20101209_AAAIVQ evans_h_Page_123.jpg
63592e2c5adcd9cc8949e05d6b83d99a
cc3102b4374b480aa93eaf72eca2effff67a8e9d
118368 F20101209_AAAJBK evans_h_Page_077.jp2
db2c4ad514254620e7c9be80d9339a13
c1bc9a66f8d3b7a2a6b54ee1d57efa77195e6a46
112369 F20101209_AAAIWE evans_h_Page_138.jpg
311527605b8465d317a7e2e89e767e0e
666a6a218f92145797c55e635ebe6f52c8732176
109860 F20101209_AAAJAW evans_h_Page_062.jp2
d1b65815b45d5d0557bbc13dda5ae500
ab3c797fbc4f13bcae5144ff4f0317027cccf899
35972 F20101209_AAAKFC evans_h_Page_139.QC.jpg
a4fabf234f61546b097d5e9748e40736
cce42767c93339f1f196f20daf7ced66d31c3609
F20101209_AAAKEN evans_h_Page_043thm.jpg
a838fb75bb79f7310d1a2c2e16118884
e4ce374a9642cec58d9578762e6b5a9de4ad3414
7458 F20101209_AAAKDZ evans_h_Page_078thm.jpg
e402e33980d655d9e3d45a6dbdc971dc
e1a653dece7cf672ab0ad21ce1ddc3ce1b3137eb
1422 F20101209_AAAJZH evans_h_Page_150.txt
6a9529019505327ff1fee6d7b79a7543
bc151148c09bdd69ca4b480c39f21a2a9cceea44
608 F20101209_AAAJYT evans_h_Page_135.txt
820dedf6cbec923c8c4fa4532e26d86f
8850b24e538d2ba4e4a73bfda7d9f3ee6d8cc961
71886 F20101209_AAAIVR evans_h_Page_124.jpg
64dccacfb13d23eec1d6aa7e70dc7cd8
a741a7adf485f6f2ddedef335c721715419ba3b9
1051948 F20101209_AAAJCA evans_h_Page_095.jp2
96cd11a0beca4affe618b37647570561
f93c03ccfc736dd7598af9418ad83e01890842a4
102542 F20101209_AAAJBL evans_h_Page_078.jp2
62d71234829d28bf1dd9a6db13830dc8
0a4b4a1c27e48190f01306437a27af4c96c19dfa
108952 F20101209_AAAIWF evans_h_Page_140.jpg
0ce74d7913a1ac0b49e9205b4429d792
b20db8ec4ea9d0be7a7bf6b8252ffb584f7a5d94
505642 F20101209_AAAJAX evans_h_Page_064.jp2
e0e162e1988f79cca4ea886f961e5d3b
b1cad7ed056d9f4562f9e851cc882aedd1e427cb
F20101209_AAAKFD evans_h_Page_108thm.jpg
76f4b65361363e6173bde7305cf04945
93eb2c275dd0682de716b59014f9f811e13cdb7e
35729 F20101209_AAAKEO evans_h_Page_107.QC.jpg
7d457cca72e281f6cd6d47e8f1367332
d0a6a365561113667dfa4c2b35b2b86c715df46d
859 F20101209_AAAJZI evans_h_Page_151.txt
7199a3c48ede7525709c330ac5c52efc
94ec3eefd34453e108f07b8a6970ea7b916f501f
2126 F20101209_AAAJYU evans_h_Page_136.txt
a90d7c82e56eca4ba972c91f772481fc
df540f9989d4fadedaca14e97b4cc99c1f9b371b
30606 F20101209_AAAIVS evans_h_Page_125.jpg
b1a9c6e4d8d8f0d8d8cf52e77df46601
68f66badd64e647d5d256af52353aa7060ea6a40
1051958 F20101209_AAAJCB evans_h_Page_096.jp2
8fa1c3b5239267583b5360d6b60878e5
e8066718ec32a4613b6d16b3add38831d9e5d89f
114943 F20101209_AAAJBM evans_h_Page_079.jp2
dd3786f228ac8d224ecee06c12ac668c
f3d3ebac89260cd039438684e4960e79511f3b1d
111814 F20101209_AAAIWG evans_h_Page_141.jpg
c7c437bb2ca10c1e44bdebcac250f995
d09e046ac78f331b8b3b4b2fa699ad80e4ad5ac2
872159 F20101209_AAAJAY evans_h_Page_065.jp2
1d9126cc29a6af5e11c85f642e5b5e48
c2e6b2dd7a7bcacc43e9e7c1f0419ccc93ff2fab
24333 F20101209_AAAKFE evans_h_Page_060.QC.jpg
6d70a89cb875e64d6b36da132dfa9e45
03ba865e982158b5f13df4762b3b05661bde6e86
35945 F20101209_AAAKEP evans_h_Page_177.QC.jpg
ad71003a808c8eb393c2070f61ed0a9e
2d79cfbbd94cf551e412cca39b146c9172223504
1075 F20101209_AAAJZJ evans_h_Page_152.txt
9cca659eaa921a4a13239e3a2d571e04
04f8e5c42f4009ef00631e0d4e8d8ae116f78c81
2004 F20101209_AAAJYV evans_h_Page_137.txt
336e27954e200df74c80b8c8d7e75456
bacc6f0d264df8d3a8d0fd9a5aab196fac214965
88581 F20101209_AAAIVT evans_h_Page_127.jpg
2bee6e08df128dbd514b3b423e6e4160
4b5aa276c3fb05994f703dd4afbc130b117c3fa5
808484 F20101209_AAAJCC evans_h_Page_097.jp2
d34a3db433b46e321f82c04d96c97c45
05b8e9e1c714c57c2570877713f5ad731cdf64ef
112087 F20101209_AAAJBN evans_h_Page_081.jp2
2f213ff721d35d39089748ca87386451
9b92805f41cc66766029c81b6bbcfc38797b3bf3
112475 F20101209_AAAIWH evans_h_Page_142.jpg
c820cea030e6110134822e4f8f96cce0
422a72a795ba46755995debdd47ee61d828b3e6c
875469 F20101209_AAAJAZ evans_h_Page_066.jp2
7a92b1fc5e1357ec8b64fd9062e10cb5
11a92c17f80bcf94751abee867ebe9dab2d39036
8885 F20101209_AAAKFF evans_h_Page_004thm.jpg
df7ae8ced99710eece64081374edbfb9
ed615cd25929f537c255cca579b0488059a97920
14068 F20101209_AAAKEQ evans_h_Page_129.QC.jpg
6dafe43ef21625d441c0d5a2f69e77dd
b16f2505de0033c0b2494870d4ff187403534002
1174 F20101209_AAAJZK evans_h_Page_153.txt
2537fff620495b98f0419393873ebaaf
847302bcb8706082099f6fbdedcfbd3e07adb94e
2155 F20101209_AAAJYW evans_h_Page_138.txt
dc0b7e68aa3c1ec58ed914456d06eb4e
9a7820ab87edcd44d75e3f6b1909470cfd56465c
61059 F20101209_AAAIVU evans_h_Page_128.jpg
a998c5325e13417da7d2ec8ea9f469c1
673e01127348ce6d48674ff53984fdf36862018b
765920 F20101209_AAAJCD evans_h_Page_099.jp2
e55e7d3ced4490000462f3e08067c611
3cd97385549bc68d753ed0fd374518c809addbf8
110349 F20101209_AAAJBO evans_h_Page_082.jp2
2c5f143f54c60d84da6d9e295e83ea97
b40e370950df6bbfdbd5c4d69dc517421eb23ed7
111735 F20101209_AAAIWI evans_h_Page_143.jpg
c99f356eaeebd48d35ead099e3534c02
0a7ecf525791d7d1b33c92064942782da1dd1185
5651 F20101209_AAAKFG evans_h_Page_190thm.jpg
8c1965b7588119ab2044f3dab52b2045
15710e57ee4e119f0da347923f564a7592aaf557
3896 F20101209_AAAKER evans_h_Page_069thm.jpg
a78eb35748e669e419b04c449683e9d7
027a9c903bccb1bdb1db0851ce54b369098b5969
473 F20101209_AAAJZL evans_h_Page_154.txt
54440a8156c5c63149315e2f1eb704d0
8bef2ca2f5ace879e8fe3c3039e3cc7884e185ae
2086 F20101209_AAAJYX evans_h_Page_139.txt
7c269539855c498cfef3560b728d71c7
7a6a8ba6338d3d4ca385ff96d333d16812d5ddc4
42626 F20101209_AAAIVV evans_h_Page_129.jpg
5fb71550446b628307b2e3193a7f739c
b282aa62395a0118eca17c7ec3d770df9d527394
994736 F20101209_AAAJCE evans_h_Page_100.jp2
a41a87ee476bef60ff838bb3ea40ceb8
6f52c9000743abce2b01aeb835094213129a4cd8
1051968 F20101209_AAAJBP evans_h_Page_083.jp2
f59e542937b44ce90cce5f0f3212f0c7
0f9c61e1ba21932c75eb34285e2abb366509cf8f
112519 F20101209_AAAIWJ evans_h_Page_144.jpg
e856db97aa5ed5dad603a13643557ec3
6bc2cb0d8e0cfab82d99a09284cabae1b365a89e
35738 F20101209_AAAKFH evans_h_Page_191.QC.jpg
566e5a761515bda490ee3055b2bb5cac
acdcb6362e81101960d7dabd214702154c266706
3808 F20101209_AAAKES evans_h_Page_152thm.jpg
b77c4d383168df28c3a27d5f77bbd1b1
8db235a1afa0762ecb8e413e880efe2875eaf829
1003 F20101209_AAAJZM evans_h_Page_155.txt
d1d159852c586a73f9866f3ae6afec04
80a87572b9bbd721e971e0e6b636ed530089cb95
2083 F20101209_AAAJYY evans_h_Page_140.txt
cf4dcec720cd48179baa2aa533122ff5
79c096c30323814a31b59846e848dc4acb387748
80319 F20101209_AAAIVW evans_h_Page_130.jpg
69faa5626cf3860dff35e5e601a22b62
5dcdd0add2dc63a1a7d41ffb5d5f1be578f5d2cd
F20101209_AAAJCF evans_h_Page_101.jp2
13c33382a2043ed9cb0d56e583c43910
052db3e6ef8c6744c6466103e53e922806ea2969
118059 F20101209_AAAJBQ evans_h_Page_084.jp2
7ef7c13b349d9450533bbf5403e69eca
d696f0620176c7ae467f44afbdfdf6fadb957b71
16478 F20101209_AAAIWK evans_h_Page_145.jpg
a1a3e50e42d8d44fbb18857a5955806f
52d1c2f513b550297682890c8e7c1e081f2089fe
4964 F20101209_AAAKFI evans_h_Page_167thm.jpg
7e1c1b7cf84dda295cdf758b222bed02
d61549e824a115f4de5d560132ed6305cd7b8c7f
8155 F20101209_AAAKET evans_h_Page_185thm.jpg
eed2d77192a311d497a175e2f0f1109f
f6c7ffa6b1a761240406246c58b525eb7c4ae784
1807 F20101209_AAAJZN evans_h_Page_156.txt
00f51e8a61551d62a059b9611359b3da
e4f50a749f31dfbbdae88273202e9c8b3895f468
2109 F20101209_AAAJYZ evans_h_Page_141.txt
f802802234dc14e66844246eb148c40c
be431f785e0bf7f50c0ed79df88dd59a5351261c
98988 F20101209_AAAIVX evans_h_Page_131.jpg
0f154f6d032789bb0fd5464ce8acc78b
ac42ca7a82c2a6a5bb4a429bfaab67c0435de8c2
810990 F20101209_AAAJCG evans_h_Page_102.jp2
b9880efe1a644435b91ba0fb948a871a
af3037d305bfa6deb61fabea8c895a707a43974e
111956 F20101209_AAAJBR evans_h_Page_086.jp2
725c718b0a0d5aefa6169ad6ea81618c
fc0a5e628754291588f8a3828905eb08ca65aed7
60925 F20101209_AAAIWL evans_h_Page_146.jpg
53f1124df2644abe81b0fabb8300165f
48bc04bb7297b90f924a1565e48c522e06d1fe6c
24982 F20101209_AAAKEU evans_h_Page_121.QC.jpg
ef8c3b3c573e048c1f05c5c6100656ab
b349dd3cacc9f21fe49353a959eb57f821f4f513
1045 F20101209_AAAJZO evans_h_Page_157.txt
753b6074141e28614fd8674aaf6b863a
86a359e7c82852ca1f68cdf23f94d5e8de71815d
92741 F20101209_AAAIVY evans_h_Page_132.jpg
ffd647f7bd75562cafab373d139ac6f9
ce4558c043bb552cfdd2d8ab21d5f8bfef315cf9
109163 F20101209_AAAIXA evans_h_Page_161.jpg
096a272e87ac69892f9e2c949b00b6d6
8aa54b497b95b359c1684fd04f887d743fe096ad
122205 F20101209_AAAJBS evans_h_Page_087.jp2
498d1e081fb8ba1508631c1e6d0b327f
2920c7743518c5fb75ce77c13511ce0db25931c1
83676 F20101209_AAAIWM evans_h_Page_147.jpg
a835879e4063f0d3f435d770aaeb53cb
8ba53bf87cf530470aa1f2b34a4daa1384cbe412
8504 F20101209_AAAKFJ evans_h_Page_010thm.jpg
678ba07a2567d7e657527ccc1dc16756
3ee28748c6ee38d0a2e2470341eee0545300b539
12729 F20101209_AAAKEV evans_h_Page_091.QC.jpg
72af8577c8a27bea8b8d3ca6d4cee9c1
61119307a3801aad13caecb6f04c326c97c1ea8a
2415 F20101209_AAAJZP evans_h_Page_158.txt
7865ad7637506afdc221b68dbbf00a00
34a65ca263d763d75336b9dc97a0b671874a2c67
76716 F20101209_AAAIVZ evans_h_Page_133.jpg
865825ba36e53c9294ec97346002c3ac
b957ade3e8d74748698dbe1f36474a327dcb6543
273071 F20101209_AAAJCH evans_h_Page_104.jp2
be26758153fd6219d840a071616a965f
bfdc17a3df322888ee1cf2212f916e5ae33a8012
115690 F20101209_AAAIXB evans_h_Page_162.jpg
60e5a65e78092cd8bfbef66fbce99289
e93af79074dc3be9e9b39d185051b8487d0acbf2
72491 F20101209_AAAJBT evans_h_Page_088.jp2
a173e4d49de04ff6c339bdbc44a241d8
5a749dbfced59ee335dacdfaaa9bc846550c2516
73593 F20101209_AAAIWN evans_h_Page_148.jpg
960daf52199d2ee28880d8e63525016d
85b87ab4e9bad27f587f4f57036e0b412090ef2a
6600 F20101209_AAAKFK evans_h_Page_037thm.jpg
1574e64a97720a118af35cd2f766180f
29996130188e03b384523bb3c65f1e92028be220
4366 F20101209_AAAKEW evans_h_Page_011thm.jpg
36811fae18ae7d219dfe179aa9a436a4
8ddb0423bb4dbacac56b2f5f38380d271f2142b6
1049 F20101209_AAAJZQ evans_h_Page_160.txt
c5aadcb1178992ac37e60b69270bf696
e126ff1b6fde68c0a3d18ea8764071ca9c7d714e
118636 F20101209_AAAJCI evans_h_Page_105.jp2
d4add024029a633a8de5dd81bcf1804a
d21b5ba8ba4f861d9dbcdd0705554540da79a956
118046 F20101209_AAAIXC evans_h_Page_163.jpg
99011d8f7fd31eb2f105809b82099ec7
34b650a1fc3b18cb797722fb09cdb6fe38ed8db2
19636 F20101209_AAAJBU evans_h_Page_089.jp2
a9fc3f7f942b98bb98d8cac072a1268d
8da0ac5625d96cf170e6d5f9db22c5b8e852eaaf
116907 F20101209_AAAIWO evans_h_Page_149.jpg
9b94059e7a6e377b58d1e5a1fe023fe9
b7e08a9acc92589966cc417bc4ccc7f04504156f
37151 F20101209_AAAKGA evans_h_Page_117.QC.jpg
f5f7cc60a3fe38e26884f2a400afece1
1c99b680861cd0009584b653795521b678740493
22294 F20101209_AAAKFL evans_h_Page_088.QC.jpg
54f8f7fda417e92f32d5cf922d8400f7
e693c80bdd437dfe8a44bd5d720daedf7fd3fa1c
16895 F20101209_AAAKEX evans_h_Page_146.QC.jpg
174894feab1aa335527cf633a54495ac
ecdeef21f5f681593fa8eb96ecc9edbe74824416
2136 F20101209_AAAJZR evans_h_Page_161.txt
6345ee6637d1ad5a212e02d39c5d1fc1
a4455a4847f68fe8bb43eb0db0930b225bf7ca1c
121438 F20101209_AAAJCJ evans_h_Page_106.jp2
8cd30d78e1a74821627959df586a64a4
eaae27631cfd88911f01315e872c1bafe0e7c10e
102604 F20101209_AAAIXD evans_h_Page_164.jpg
82afa932510ef35c5fd6dc8ade4ee7e8
f257904f122977b7cb346182076d271d47860cd3
61043 F20101209_AAAJBV evans_h_Page_090.jp2
23bca545c8a176f596bda4cdfd4f1afb
d6bf3052cf9e01bf133914e27277496c8bf8bfad
117979 F20101209_AAAIWP evans_h_Page_150.jpg
def6dfdfa541cce6fb59e38f6c1b35db
6e2629cc989007a6cd7e4f654a0a84c93378bad8
3974 F20101209_AAAKGB evans_h_Page_122thm.jpg
baa8458f27e08177855bb24cdfc75c35
52e8c16ec2cdbc579802b49f277b606e983a46c3
37826 F20101209_AAAKFM evans_h_Page_197.QC.jpg
8e6c91020fda8ec91e5e9d77ed553fec
189b90b0e17fd1f9fd627a7f2aad4c692e958cab
8614 F20101209_AAAKEY evans_h_Page_023thm.jpg
fefaaae98e8e34ad65329a1d938b7f4d
c843770bb609182449ded7ca1cbcff88e83a4df5
F20101209_AAAJZS evans_h_Page_162.txt
0def68ae832d4eacb32be4dfb06e6f88
7961a2c128c827eca93d2cd3ede8fc8ba1c7c822
114494 F20101209_AAAJCK evans_h_Page_107.jp2
d659bb89b855c2742a0a187ace910935
c5615165671552875140ffcbb7655780d47bcee7
59561 F20101209_AAAIXE evans_h_Page_165.jpg
0949a6d8b7d609d04acc86e9cae89423
8975456c72137d2e2bcbdfedc53780f32b2eb78a
46663 F20101209_AAAJBW evans_h_Page_091.jp2
0e1cc26919d53082a71d67c0b2e4d147
f40b85d69c0e104a0eeaa74bad4cc9b9b5262e30
49201 F20101209_AAAIWQ evans_h_Page_151.jpg
2c35d87b3b0b52c9d874287dfbcb9225
49bbb7775af51a2190d916822e42bbb7f46edb51
37024 F20101209_AAAKGC evans_h_Page_141.QC.jpg
61bd2be61ea4d41110f0cd1567f29d66
8263401024e3460c75000640e21299926d2e7b83
35732 F20101209_AAAKFN evans_h_Page_009.QC.jpg
74ce2322020835074f66d172ebeeda29
2cd01461c7681d04c622c1d380f4a2be3d336a91
35824 F20101209_AAAKEZ evans_h_Page_053.QC.jpg
7b561dea2fe53562ea49d2cceca53e8e
736defd8105112b44557a9d2e73122a6a8e47fda
F20101209_AAAJZT evans_h_Page_163.txt
8e8925d480a0c46a765ca95da5f4d74f
498fe1415e746254e05a28fc341ccd36c2120268
120134 F20101209_AAAJCL evans_h_Page_108.jp2
b4c759f41b94ddadad665e65b3f2b823
1966459371b03ad4722d7e99ae476c7ee6ed71c9
69249 F20101209_AAAIXF evans_h_Page_166.jpg
5fba9aab3ba32907b73525f23fd98b93
4e8de5fbfb51de49db37fdd692aa16f09c7ed628
917494 F20101209_AAAJBX evans_h_Page_092.jp2
f6d4c2618f7052b405761f43dab4c08e
73397ab23eee32a1d1728ec18cc4814d5e03d7e3
41543 F20101209_AAAIWR evans_h_Page_152.jpg
e786989cd1eade42b1377cf46e5586b1
c684e0fbc51621d072de53d5bdbc93947a347f12
1051927 F20101209_AAAJDA evans_h_Page_127.jp2
6005c3ee55ad1cecc1fd344b630bb5b9
06c6d6039ea287319e0123d778e1a1fdff83e5e2
6381 F20101209_AAAKGD evans_h_Page_166thm.jpg
84235bfd8f5917efe257517cac2121ee
3855c6bf54cb591ea4bf2d38f31aea8ab9ffa0e3
38830 F20101209_AAAKFO evans_h_Page_163.QC.jpg
e2644daed43bf9f337798c9cb1b28425
12ec9f8a1cb14069ce1d5e2aec1eb9c7e638f62e
1958 F20101209_AAAJZU evans_h_Page_164.txt
1140f55e3ca78fcc102ff193ac938f59
535a4cd773dbbbc84b20e7c62b5c42dc795393dd
119476 F20101209_AAAJCM evans_h_Page_110.jp2
bd904af84fea51b1a587b730b4f2628d
9361ceb4e6a6f86b253696ece4ca78e5141aecff
78698 F20101209_AAAIXG evans_h_Page_167.jpg
c1a39778e54933947897828326137bcd
7091629340356e482a0c80f06e5a106201ccee2b
F20101209_AAAJBY evans_h_Page_093.jp2
862b9c3fa91b9c4f5d5c985d89560a17
d5e6c6eec768cf4bdecb9f70939ca30646704a93
103321 F20101209_AAAIWS evans_h_Page_153.jpg
61fc05051b428b31e15367ac85901489
7d1c758f08fb8c35dbaa078b5c88ab967bad8cc2
926089 F20101209_AAAJDB evans_h_Page_128.jp2
973a5c5d5f4f38f818588cae18ce3ff3
be87579983ea66376cbeaa3d4eb5c366178eb494
8913 F20101209_AAAKGE evans_h_Page_021thm.jpg
1b453ec2505e35f8109d9df85cbc6dfc
7a902d4fbde7e1fcbb5bd35a99648925d792b321
2556 F20101209_AAAKFP evans_h_Page_186thm.jpg
9e9702b707dcfccf20cd7659f65ae09c
c5be5f84d7d661a9e15a2d7002f8af7635442f49
1121 F20101209_AAAJZV evans_h_Page_165.txt
7bbc1958b17d95a3713ed94c10dc1c5a
63941da923d7805c1de8ae8c2f32a5df737d5be2
115678 F20101209_AAAJCN evans_h_Page_112.jp2
661c2a1bb491855e39a254b79b01951b
aadbf1299c0a8027df8361dcc2eeb56a5104a77a
66604 F20101209_AAAIXH evans_h_Page_168.jpg
1c81f34b176fc1c22bd3b35e7b912568
00e6dde386d4a208cf494a062fb645d6d0285808
1051959 F20101209_AAAJBZ evans_h_Page_094.jp2
d014743e141bf66d390809aba2b7a6e8
00c8e95a64f413995c7b8f14c1132f75a67ba7b2
45682 F20101209_AAAIWT evans_h_Page_154.jpg
5c0c52cfb00e9d4518c1f8bda19aa094
d06cf3027c8d957f757adebe69f8974c74e18300
434397 F20101209_AAAJDC evans_h_Page_129.jp2
3892acd22c69abbfa990e8b20689f928
3ce743c02a5cc8bed22bbb7456b348ace525c4b9
36093 F20101209_AAAKGF evans_h_Page_161.QC.jpg
5be9dd0f4084819e39753f82d70b0924
80e83e001e04d40907cb2b0aa233f57b24b557f3
6193 F20101209_AAAKFQ evans_h_Page_183thm.jpg
e7fd20d4973d272fe5e19afec5d50007
2984b44252d03ce5c53e19deb70c09cac1be3365
1454 F20101209_AAAJZW evans_h_Page_166.txt
8417f98893cb1497b0fb86ef8c31ac23
2dbe8720bc4c4d101444b4ee992de24ee9994c32
117816 F20101209_AAAJCO evans_h_Page_113.jp2
f2d622bb6d0c6b3b193c841c7d548be1
6c67fa1c3c9a96a2528cf998f8bae52fb5cfce3b
47954 F20101209_AAAIXI evans_h_Page_169.jpg
92e24859840b585b4f22ab0307442de3
33b06514703df60de54244ed604b9491116ef807
94655 F20101209_AAAIWU evans_h_Page_155.jpg
2e4aebe26d8233d30574aed44823315c
c729eff07365e79374a45f972426350473e90baf
1051926 F20101209_AAAJDD evans_h_Page_130.jp2
1604b2f9a2737151ffda7bfe1a7ae96d
37e20c3188a834057e98cf812e1dcb41491ae50a
F20101209_AAAKGG evans_h_Page_049thm.jpg
2d0429dd5ccbcec4f247323be6a7d890
a90e6eef79d00bb4350fa012de24389023c0a429
4642 F20101209_AAAKFR evans_h_Page_059thm.jpg
d4c323e389bb4d880024b0933c017902
bc7f537b715293e61750ee7ca978aea068df8cf2
2297 F20101209_AAAJZX evans_h_Page_167.txt
17103f7d3a29f4b10adca2e878963754
e15098591a1a05fcafb72f57ad307b4f3d16061e
119752 F20101209_AAAJCP evans_h_Page_114.jp2
c94b4518ee8afa102c703e29bda3ea93
6f67840112b51a870207483251bbff67cd9e5baf
83828 F20101209_AAAIXJ evans_h_Page_170.jpg
b351864188e7afdbe5e804e0a2b8ff14
b10465dada106e61d213af4b339439c520aa8e7f
86088 F20101209_AAAIWV evans_h_Page_156.jpg
8713a21e4d1fdb68947c05f13e8b702e
c4adadde495454a85d034780aecc7584da1f8e5c
1051946 F20101209_AAAJDE evans_h_Page_131.jp2
8c8831ed8f32b71d1fec617717a21666
dea864a864ad7225ec9eef9ff53ebf4e22bbf6d6
8861 F20101209_AAAKGH evans_h_Page_111thm.jpg
466d73c525b0161a5b4c79a00f2c4c6e
afb3d93799eb5545e64ce16db490f244f1b4234c
29447 F20101209_AAAKFS evans_h_Page_006.QC.jpg
13c40716b135a4b5461467c1ecc0cab2
a527d8b4539921e3e7c31407e36714425ae09849
1492 F20101209_AAAJZY evans_h_Page_168.txt
bb4cbbb830db0debe47e75c440c68576
aca2f29d9283fb748e406d404bef8efdc1cb3275
117876 F20101209_AAAJCQ evans_h_Page_115.jp2
3f9ee66ae00ee27bcb6007e100d9bda5
61d06f65d66021f2c41cb7dc2315c9238b22b1a4
104941 F20101209_AAAIXK evans_h_Page_171.jpg
2f4b06703addeeef6c86b03469ee38f3
e01a701647c82f41f6724acc421ed2dd33d31977
81671 F20101209_AAAIWW evans_h_Page_157.jpg
3dc56bdb25d78530de89a96834c3f167
bf522e540c3ced559159c7f116b78a94d326e324
993691 F20101209_AAAJDF evans_h_Page_132.jp2
f621ec737fdedebe3fd39dfc6b935eb7
b6184215b9f64e6c4c5174eb6cff1e0c33c34a00
5793 F20101209_AAAKGI evans_h_Page_027thm.jpg
f8f3f68a3b654e7cce0991fd33e93a86
b1fdd49e7b92a31b6c65483e6830fce7cb8f57ef
7612 F20101209_AAAKFT evans_h_Page_093thm.jpg
1b1e6676f3ea95e38cb3023688818b56
00ef543b6eb9115e6517c960d6bb0e6cf4bec104
920 F20101209_AAAJZZ evans_h_Page_169.txt
fd31c8408543fab564395219c83ac221
a59e0b37669256bada59934d7f2f6f916fb3f711
120551 F20101209_AAAJCR evans_h_Page_116.jp2
a084c07b0662364bdc439e62c3bc5b51
429a9fc068b456e8c0f3c62d83478d56d290f5f6
109433 F20101209_AAAIXL evans_h_Page_173.jpg
40e39f239fa65340a5ff6c70c67abd7d
45f9b2f32b264ecfb22805c25e7b7af6a37a99f7
105389 F20101209_AAAIWX evans_h_Page_158.jpg
43f0c30ac7ad36d4274e3fe87766b11a
1a6ae79a5497c1ba29caa65b4723d25b0fa55acc
1051980 F20101209_AAAJDG evans_h_Page_133.jp2
8d06e245fcbcb6725b91e212a881d155
b6983c999a25f98f4c0122721782f07027ff66d7
6553 F20101209_AAAKGJ evans_h_Page_089.QC.jpg
13b4012e216928f7025f0e1d92f2ab92
686ab9d225c5d1acaec55f0a1489a85f673d1dc9
8245 F20101209_AAAKFU evans_h_Page_070thm.jpg
b566da47d38f71e1687f2bf767f87ba2
3288411bb227c687c1095434cc5d2b0476fbe3ae
76927 F20101209_AAAIYA evans_h_Page_188.jpg
db65111720f3e7b9e87a4e57d1e7ea8f
b93bc641e23541a60d0cf899359f1536a2fa09c8
119737 F20101209_AAAJCS evans_h_Page_117.jp2
84ae11b785f94efa0a1fa25ccaa85e47
5f2886b94370a83836972e05ffce1f2da2f291a4
F20101209_AAAIXM evans_h_Page_174.jpg
386556d9eccdc834ba693fee98660167
a9f4f8dd2aec16dfa7bdaa9d4141e4fdd9588a19
83787 F20101209_AAAIWY evans_h_Page_159.jpg
e76aef84dc36f80256f1fc7313b2dcab
2a9b4350febc01b2f2f698c6078486ab8e1c352a
578673 F20101209_AAAJDH evans_h_Page_134.jp2
3bebf314a5ec09b6967aa49870703870
c31481eb87ea290f318147cb9b043dd42f52eadd
32262 F20101209_AAAKFV evans_h_Page_158.QC.jpg
63c9e745e9180f6dcc35e45cf01a913a
5567de9f0fd4fc65fd5fd8894c74fb757d67f1e1
110563 F20101209_AAAIYB evans_h_Page_189.jpg
1dff6a2f4b2753c7ef468d1b851677a0
1229b3e40a5dcc18f9311366aa43562a3a4e8d52
115548 F20101209_AAAJCT evans_h_Page_118.jp2
826c1538737e4ebf8d13e80a15ac08fa
4fb8d2712d872bdb6fb4b0fa6d4885ab4d5f125a
113149 F20101209_AAAIXN evans_h_Page_175.jpg
4d41578e535288b69d95c735d3582ac4
74bc26f4db7aa5f2769d08ba135f78cbf5996d4e
44306 F20101209_AAAIWZ evans_h_Page_160.jpg
06728a01dd56711ed8cf1fc639b93066
62edfca3573d74757038459a3fd5fd3f274b13bd
5913 F20101209_AAAKGK evans_h_Page_188thm.jpg
8697be31908be610ae8f90a312076876
e598c17c55e810eacfa678560782975fef6cac7d
8264 F20101209_AAAKFW evans_h_Page_015thm.jpg
2bac8ce89df116aa35bda368d948010a
7c177e1599ce24f174f246c7fc03b989c860c6bd
109325 F20101209_AAAJCU evans_h_Page_119.jp2
60a860901fa612799326940f4a4398f4
53d89eddba42b11cd1b402a982aef865e201a65c
107074 F20101209_AAAIXO evans_h_Page_176.jpg
8700cb61e117343ec6d8836194903122
b1cb412b6538c3412de5baa54082bd2a96355475
931118 F20101209_AAAJDI evans_h_Page_135.jp2
be1d5df8d1f0e8ee17cd88c868b3c34a
8bd8a0f38c4031f33adb9314a909dfe01d0b7871
71060 F20101209_AAAIYC evans_h_Page_190.jpg
759959affabe40803a0c6ecb25551d01
77d05080c450c457468eecc093cb475a9482d8c9
4547 F20101209_AAAKHA evans_h_Page_013thm.jpg
031de2f591564c751cc857ad26a069c8
e25eb574cc50d9bf782dc8e4ac5380193371cad4
302270 F20101209_AAAKGL UFE0017566_00001.xml
f91d69daad226d5a033f31674f52758b
79de6faa7c408541deec57eeac116c1683ff686b
6229 F20101209_AAAKFX evans_h_Page_066thm.jpg
fad72201eb034cc978a247f977aa458c
462ee769f79e7333daafb2ec563c9860d2d09340
1051942 F20101209_AAAJCV evans_h_Page_121.jp2
6a881de7862604d6e2e4c6279cdcf472
01319ea29faddf3b1f9ae20aea0160e09ccf10c6
110576 F20101209_AAAIXP evans_h_Page_177.jpg
2a39c511f1ed304d77ff521db2480cc8
21296bbea24219dfb8efd078ee4425d0760815b9
1051949 F20101209_AAAJDJ evans_h_Page_136.jp2
e358177ca705ee2b4f7161af6428d6e1
f65cbe43ab8a818ba6e01e24751473bd839466b0
126697 F20101209_AAAIYD evans_h_Page_191.jpg
34caa1067a1ca5cc4980245ea63adc45
a4feb71efbbc9a6caa82a71d1c9604c8e0d1d3d9
32263 F20101209_AAAKHB evans_h_Page_014.QC.jpg
a325dd4f09dae3fabf78de52a040e3ca
ef0296690fc291ff4149f4b748425070c089e614
582 F20101209_AAAKGM evans_h_Page_002thm.jpg
0d2fbfa0c45298e5a79a82a66470c89d
4315eea8c305b80c947ed6db1b1b6ea15c7a69d1
6648 F20101209_AAAKFY evans_h_Page_121thm.jpg
e1e3b7ed69e5efc309de6da1de136c3f
ebb541101b36fa8597d4c86d6049b20d30b66fb1
528197 F20101209_AAAJCW evans_h_Page_122.jp2
52b529d319d2eaf11ef34aa864d29910
86ee887ba46a74ef20b4730a89f425c323db8278
112690 F20101209_AAAIXQ evans_h_Page_178.jpg
474cba278ac45873a0ad6e68b6e04ac9
a494d275a35cd436bc63a6a6facd837c218b6e5f
1051944 F20101209_AAAJDK evans_h_Page_137.jp2
92d8e3145984123df07c8a033ccba411
6829f842e632373a773023feb765970c0d98b7ee
139271 F20101209_AAAIYE evans_h_Page_192.jpg
4b3acfeda5808066c4a8937d96edf551
c8f6c475fd6722a49e08307048d517bf599ef04a
35459 F20101209_AAAKHC evans_h_Page_016.QC.jpg
bff666622207becf53f6bf132af1af85
1646a7ca1d81743ccd36216e27363ef0382adcb5
1567 F20101209_AAAKGN evans_h_Page_002.QC.jpg
cb3558fd1f68a5ecffc05140d4bf4b7f
1ee3b0235c1f268723ea09f212505a5307f65b89
19317 F20101209_AAAKFZ evans_h_Page_013.QC.jpg
078b8ec78f7cd1071d17d2ebb3ea7d7d
dcf1d856eebf3fe343a153eea5a70b034f52a07e
435597 F20101209_AAAJCX evans_h_Page_123.jp2
ab45b5ddd8ff6ff51370ad420832b6cc
61d17f2a2b7071233b4b0ff5bf7c53a257fe9baf
110248 F20101209_AAAIXR evans_h_Page_179.jpg
473ce34a3df6b33e01c8d0e2959f6ed7
fcf524bfb4cddeb67764e9383c003c0174debed7
555403 F20101209_AAAJEA evans_h_Page_154.jp2
1f6e35ea81ca3c5cca50e1f2c78bbc39
2659abc6e88b30dc95100a192a0f26e3825a7563
117098 F20101209_AAAJDL evans_h_Page_138.jp2
e3ea761091fb406b0322349e8aa49d39
cd93592a4b4082c2d8c157372f662c185fd07465
136572 F20101209_AAAIYF evans_h_Page_193.jpg
af720b11b1b9e30987bf2a979e6e0af4
39c9b285db0837b84361ead94f305800759f9245
2777 F20101209_AAAKHD evans_h_Page_017thm.jpg
66c80c33017db258098c8f4f4b825972
ec729c290682e816dcfd6c23a62f0e32c0365054
442 F20101209_AAAKGO evans_h_Page_003thm.jpg
72d23a76f70d85fb2fb9a1ab77869f27
dcdb5d0390af299fe8476ec65e363687e769adec
367533 F20101209_AAAJCY evans_h_Page_125.jp2
6fbc13927766009b391a13e98d230670
c9d4fe0e56ac8d7ebef358dce794c91875e627fe
76736 F20101209_AAAIXS evans_h_Page_180.jpg
0ae5099f7d7bc51fb021268b905e8f42
9c6885b0586d936bebd3047318b9d393f9c15cc1
1051967 F20101209_AAAJEB evans_h_Page_155.jp2
db1bde592fa95cb3ded508ecdb32e798
2adf7a3a028347c1ef62469e8019d4739bb4a2a8
115801 F20101209_AAAJDM evans_h_Page_139.jp2
cf9351a89b0d66c6afa8c89384418af4
4d67828b2a6241424a840f28eba6d2e77a0b938f
134110 F20101209_AAAIYG evans_h_Page_194.jpg
a375a8ffaae8cabe00c44f435c3a2bbd
f14447ac1035df1f232a5760bec4c40b265a3b5f
8863 F20101209_AAAKHE evans_h_Page_018thm.jpg
fed7e7cafc47c18660f2a22ae19ab6dd
e10e2dace7e165be2cab7e361aed21b916671d6e
F20101209_AAAKGP evans_h_Page_003.QC.jpg
8c87dfb73f2d4eaccf9f1c39c34d9d6a
667246b6decd4140b16d3da7b5de884edd069243
822427 F20101209_AAAJCZ evans_h_Page_126.jp2
325f08994e1101c5d90977747a652d81
9562d74ae3ac7590559a6505a45cf007f95d39d1
66104 F20101209_AAAIXT evans_h_Page_181.jpg
c7a1be8de7d21e517c317eb196b4801f
b1ee41966b5443c3455fe2cae8965d4fe48c9715
1051982 F20101209_AAAJEC evans_h_Page_156.jp2
2123a7467198ca37bebeea903684451b
b7e0ae9fae6a3758f70fbbf8b83014317b156cc0
115191 F20101209_AAAJDN evans_h_Page_140.jp2
ade6a09572d4c6e9ff44836a4b2bb429
dbcd33bf056fe289da871ae1b71a2085c8e72b9f
123195 F20101209_AAAIYH evans_h_Page_195.jpg
003637ffae32f704c8c459c2ba26721d
66f5012efbb7b3a3b118a78a2b9be1f122561571
9144 F20101209_AAAKHF evans_h_Page_019thm.jpg
0d6688e845cd073b35a03a5b69f15efd
0b179090c07253f415cab25b18a8c7541ffb549b
35392 F20101209_AAAKGQ evans_h_Page_004.QC.jpg
b44fa8de30baa703851099dcc1e87258
09753b7d8bea580124f5a08c8f7d115446e73d85
45191 F20101209_AAAIXU evans_h_Page_182.jpg
2c7a89d5e21eecad5203eb8b2ccb0d78
ac7c0b82b08c8852ed9edd4db119476908e54dd8
1051919 F20101209_AAAJED evans_h_Page_157.jp2
7d4ff3fd125c099a36bb0613ea6c9817
3ad307e28997b94cc5080f02ee8b5a8bf6b1d3a1
118351 F20101209_AAAJDO evans_h_Page_141.jp2
16c3fb36ad93daca95898cf15163a969
611b56f03f2ba77b53df5461442704bff25ae523
131709 F20101209_AAAIYI evans_h_Page_196.jpg
19fba53c725fbfe54b2b22c739a94d34
43dc6720d12b720010c57758a06e8989caa52c6e
37759 F20101209_AAAKHG evans_h_Page_019.QC.jpg
1dfd98dc52fa059d8f3c3420f0b274c2
600c7d9d14f3eff4e4864bf9e25cb28b3aa0a6f1
6522 F20101209_AAAKGR evans_h_Page_005thm.jpg
86f0fd48b462d85978c38b1e6d0f7ba6
511c4a27af1a891f7503d605f1eaf5035efff045
74322 F20101209_AAAIXV evans_h_Page_183.jpg
4f48a3f344486198ad1c023dff337b49
dc3554f3bef861bf15b8efc65510eea0aa7b8ef9
1051908 F20101209_AAAJEE evans_h_Page_158.jp2
69a3d2e5f7bac2f2e5d7a33b72d7f641
5ff73e316869d1c264d6c5fe78ac3025d1b66686
120181 F20101209_AAAJDP evans_h_Page_142.jp2
9896148218b72ac1636157f2926a156e
5214888824a0f2f4fa50bdd34edf172fad4a8507
128859 F20101209_AAAIYJ evans_h_Page_197.jpg
4d5b4447cfeeb31e89b381e9da3d296b
b960b4921eabc5a6da001362ffaaa0cc16c73353
8845 F20101209_AAAKHH evans_h_Page_020thm.jpg
74cc09b70e252d48179680851bf297e0
4e5a11380129d947b4d2571e6e45b977975572b3
26171 F20101209_AAAKGS evans_h_Page_005.QC.jpg
0a1225d9e0f91c38fadc840478dc719c
f9a4a6260d41ee05dfbd3aad5246c730074f37f2
53687 F20101209_AAAIXW evans_h_Page_184.jpg
ab55d921492d43b14ef2625a86491c62
12858e29a28d79c1860b91a1a771618705f7a056
F20101209_AAAJEF evans_h_Page_159.jp2
9e6ff29b2ed1b4bdae7a7d41633d278f
3f1b0faf15a5313c29e289a1fd9057df26d1141a
116803 F20101209_AAAJDQ evans_h_Page_143.jp2
53222a067cd92998372a68632b2f54a6
250f2997c3409a6db6f17f32cf5ebc75ab86b858
142672 F20101209_AAAIYK evans_h_Page_198.jpg
142770941384d6ddae6ee51665582f09
7ad009d6c6d6494013709474cecf8d926962ae73
35634 F20101209_AAAKHI evans_h_Page_020.QC.jpg
1848b59b349004c43d74d6213bf85a79
0afee38bc43adca108f84ebbc31655480839195a
7271 F20101209_AAAKGT evans_h_Page_006thm.jpg
cd5a01c23c95c1b52542daa90a1da192
534a3ae0e21394b902a31bf08637fd63ec82246c
96712 F20101209_AAAIXX evans_h_Page_185.jpg
4e45b00ac1e8233736a4f098b15c2208
ffe1224fd18d740fafbecc56c0233209aad7063c
548182 F20101209_AAAJEG evans_h_Page_160.jp2
c7f1d5ebe469e55ba552642d247ae64b
06d9bf351f0f596a8f139054799385de81810eb9
118932 F20101209_AAAJDR evans_h_Page_144.jp2
c061d213b33b3e370d01ed817f30402b
4313a38d694b95da8653d6536a8344f63bbb894f
129621 F20101209_AAAIYL evans_h_Page_199.jpg
4532f996f81cc7718ec566b9315dbd36
e5a2283dd21f43c7e7a38b553c51568c2c82d535
37171 F20101209_AAAKHJ evans_h_Page_021.QC.jpg
db898bb48b7b523c63196530bbb16168
45052a847cadda29cbfadd887a3014276ef66e44
6835 F20101209_AAAKGU evans_h_Page_007thm.jpg
fefe05e240db4bf16e8c270fa91f6f0f
916a688bfa63f70ea58f0a7f5c1f970c10261ac9
25879 F20101209_AAAIXY evans_h_Page_186.jpg
1c27b869779fa647460400f657772948
92e803fe0a96605272f395b086cb7411ec6d6523
114287 F20101209_AAAJEH evans_h_Page_161.jp2
778a1992008c3bbd84bfbfc01c2d9bfc
c6d34d46d4a118c35fe43ce22d3234571b0e683a
94764 F20101209_AAAIZA evans_h_Page_012.jp2
04bafc66a20a7d1379cdf952e27c1c41
bcfec97689d125b4cfa21bfed93a2433cb2a7cb0
17417 F20101209_AAAJDS evans_h_Page_145.jp2
543a5608f3dd41f3ec46370ded8a8327
834ee0bb068b352fadee2001aadc590cf71a5d29
131259 F20101209_AAAIYM evans_h_Page_200.jpg
eb114f4a457e77ae1f090648418fcee5
b1314bcd435acc2f8e8ea2078f4b24cc904b1df3
8875 F20101209_AAAKHK evans_h_Page_022thm.jpg
a6b37352cd934340fa8dd919792eed67
6f31b65fd4a29bf46e7132dd4cd0134c7763d1e6
32711 F20101209_AAAKGV evans_h_Page_008.QC.jpg
d2cb9c29ec67743606465d5ec0bdb2c9
c42dca0b6365599b1ad4c2fe8bc704450c38ab77
50127 F20101209_AAAIXZ evans_h_Page_187.jpg
85135288cef5aae7e33583bcd4429318
250a4f0e4ed0c7331cc71d0f30de1f748e8584d9
121919 F20101209_AAAJEI evans_h_Page_162.jp2
e292162a9577c87138c2381bd8931cfd
1ccf8cd2ab70e3aec4ae0dbbd6dfc41579117771
62698 F20101209_AAAIZB evans_h_Page_013.jp2
d2db29a27f3a5df08ddfb0231a27ab2b
76cf18e8e1273475bc45413532ced2d42d2f18cc
62237 F20101209_AAAJDT evans_h_Page_146.jp2
ec8d6b9120190aef407dadb4b3205300
55a376035721df783f7bc3e774f3743dc279ab47
144403 F20101209_AAAIYN evans_h_Page_201.jpg
978fc172990a63b3cdae6c912d43cfcb
ab303406f35b48a9ddddb654cee4ee9323c2980c
8358 F20101209_AAAKGW evans_h_Page_009thm.jpg
7aed84a480a54d07dd18b015a06b57bf
152da00fa80d97721693a9806b702fe98e95a3fb
108657 F20101209_AAAIZC evans_h_Page_014.jp2
e95d7f92af58d70ca9d394c461ae5c4e
85b57d3ed6f3fff051bed7d5201e1e008dc13928
1051838 F20101209_AAAJDU evans_h_Page_148.jp2
839254081755708f9d65975b0e01e4ee
afcc127e4e98fcf4b3a2ee5b2feb18a9f2d15d06
119784 F20101209_AAAIYO evans_h_Page_202.jpg
836b4d8e991100992c0be3a51cee2ac5
d7383f772bb75afc11cb499e38700f55cb9a08f9
21890 F20101209_AAAKIA evans_h_Page_034.QC.jpg
a9883559b036d908d48c65c44bddde60
8a66230c2857ecf77374bf49f2bdf6b8656bd642
36531 F20101209_AAAKHL evans_h_Page_022.QC.jpg
64069265fb6ac2e6530030b535f61287
8a8e84c7d85c5a6b73dc0abf9761d678fcb1b655
36142 F20101209_AAAKGX evans_h_Page_010.QC.jpg
b4b8ac36124eae4fe55ee35535000038
f602b89a33b7ae6a9fd89f089fcfa1f91059d9fc
123618 F20101209_AAAJEJ evans_h_Page_163.jp2
9ca1ec205ad16611e3ac916769f964c4
951e64a7ecfcbd7459f187240de5c9bf2843d520
110539 F20101209_AAAIZD evans_h_Page_015.jp2
9030007f331c198ce783655978fcc67d
22af3e9ccc852ef3914efd450a789c9439a30e65
1051891 F20101209_AAAJDV evans_h_Page_149.jp2
e60cd8ae9d7a6164220ac9b6be15d551
84b67c81e391090f5c6192d38d2212409ee320eb
83046 F20101209_AAAIYP evans_h_Page_204.jpg
36078ce7a6055b6cc2e97425d7c31373
a8b51eb77558a44ec329da381639c4d2e8cfd072
6378 F20101209_AAAKIB evans_h_Page_035thm.jpg
d4f901290e200d37c19d864600f545f8
f5883e8c14454f961acbf455b171b9cb23adcb91
37291 F20101209_AAAKHM evans_h_Page_023.QC.jpg
af23fcc47875049cd6f267c3ba103f70
661a0eac90de16410978fcc9a892a1678a23e76c
17811 F20101209_AAAKGY evans_h_Page_011.QC.jpg
67ebee645438e2270e7caec4b88927a3
945d9f10f7e66e9ad2feb9f9b2995e0c42503feb
109151 F20101209_AAAJEK evans_h_Page_164.jp2
c13d42a9ed5b2ce762c00ab3d0af7bc9
8436a9fffd51c4cefcd620a12cb68a4f55895c5f
117636 F20101209_AAAIZE evans_h_Page_016.jp2
3149fece6af1ac3955b9f5cfac0b1ce1
52f67c4c7780c498a7d12e35454ab010605d86a5
1051979 F20101209_AAAJDW evans_h_Page_150.jp2
6ae5375fae868370eb7ac64cbeee9837
746c7c530d8b91de03ed15e6fff1f1c00ddd61c3
24544 F20101209_AAAIYQ evans_h_Page_001.jp2
82d3a37e516a1fe0566ede78ccd1a921
950c464e101eeb862e6450c8485857c3def75fd3
23788 F20101209_AAAKIC evans_h_Page_035.QC.jpg
ad049c5ce45540539502d241d2bcb42b
346e2f0532345f32490d5eb1394d264973c298cb
9159 F20101209_AAAKHN evans_h_Page_025thm.jpg
23863ecac9a9f0db05e7fdf7a89acec8
6d6a0d40e9c334c2521642a46a716a2e9bf896b9
27835 F20101209_AAAKGZ evans_h_Page_012.QC.jpg
88f2db9a86cfee3447940a46571dd1c7
f69fab9a0489f0d87ec40d3c691e7db5388fd874
63568 F20101209_AAAJEL evans_h_Page_165.jp2
ec7a5676e04955bb08d159a3130bbf46
f68332db50642edac4ca72d60e11bb6d3ee377d1
113619 F20101209_AAAIZF evans_h_Page_018.jp2
0ca9df60cd8e3c45adf4237b070cf81f
13a8a0171a4eb54bbb1298bb3ea800ee9049157f
497129 F20101209_AAAJDX evans_h_Page_151.jp2
a104d9f3870344d37235338b204b6de1
6fb1d033f0d7d03a670aafbf47ba6737147d0383
5690 F20101209_AAAIYR evans_h_Page_002.jp2
735cb720124930fb6ed016384dad0b2c
223ed97a0e2136b06848c44c73c9cbb7675e2cde
76119 F20101209_AAAJFA evans_h_Page_181.jp2
b1660109f81bf9de515d7bb39bb7c6bf
5bb5c5158c5610683a34bd5806bde72bcb50ab7c
4884 F20101209_AAAKID evans_h_Page_036thm.jpg
465d9427b30384c23bcda6dab71476b1
a83cc039c5c82bd876da4e4e3f247a50b3056060
36366 F20101209_AAAKHO evans_h_Page_025.QC.jpg
39efe5bad4aa7a9e6a03deca14958926
33d92b153066b8839dad608e587c9007a079784a
65963 F20101209_AAAJEM evans_h_Page_166.jp2
5fe71c5cc2ec35ce2037ba90ae02ae6b
1f3308ef4dd55458e303f2978146deefab1b0d38
119538 F20101209_AAAIZG evans_h_Page_019.jp2
74bbcf8d8a0dfc84e75af7efcae05652
ba01bfee17ee354526ee333f371bcc5bed08e472
415431 F20101209_AAAJDY evans_h_Page_152.jp2
d4205f03adea8a8f8fe84af4aefd1548
055ee30bafa92af6a4ca47e4a6252fcd4973eeae
4498 F20101209_AAAIYS evans_h_Page_003.jp2
eee119bb2ea9871a11aa4fbf276e69de
9f91f1af727192076b7c86d2ce7a452291e33156
448711 F20101209_AAAJFB evans_h_Page_182.jp2
40b541ddf9ef56b860cb24e10718cc10
89a81c8d90c5f7eb40016de9a1530ea584caa361
16918 F20101209_AAAKIE evans_h_Page_036.QC.jpg
7b37c4503eb46b287cad03b386ebba8e
f7370b5f4f1825097182af5502fa1fd862392d2c
8984 F20101209_AAAKHP evans_h_Page_026thm.jpg
4549d0b24fb8096e25d0a37b2fe39292
85129648fa9babb31f2581b1d72c4c15d000db5b
79496 F20101209_AAAJEN evans_h_Page_167.jp2
bc1b73ec7b3b42f372444d7cb3cd89d9
908d43d3bcfba57fa79706619e946006d17ff88b
114641 F20101209_AAAIZH evans_h_Page_020.jp2
c64254b618e298f68852bf6b71b7a4b7
a2ba8e144e031c35fbc27dc5aaa962eb9e2d15eb
1051975 F20101209_AAAJDZ evans_h_Page_153.jp2
1a8cfcc80e5035e98620765f01ba0eb5
6e9b564f80ca1c0702c97a19e70c6e34217a0537
114986 F20101209_AAAIYT evans_h_Page_004.jp2
4926bcd647f804b924fda8fdebb1a16b
1f207764ad603e9574998b0ac0c213563e72eef2
821403 F20101209_AAAJFC evans_h_Page_183.jp2
37d1bd3c4cf3a822e838e3ee6d4b09a4
61d93477a8752c79b02b3b420ccbbd80df5d6aa8
24721 F20101209_AAAKIF evans_h_Page_037.QC.jpg
a33d510e492d8cb4e5c4a6c8866c39c5
421d91d6eb62e6307fdd12e85f55069d5fac3f3c
2483 F20101209_AAAKHQ evans_h_Page_028thm.jpg
c3f8a36e2674690f63204e916e474094
a86d2609cdb60c454a62516b5c166a3f0abbdddd
695795 F20101209_AAAJEO evans_h_Page_168.jp2
d74477f9179f85b5db1aa33b2a9a12fe
3cf28e24adb50f66a0f7d9e6d9b087f6a9985955
119850 F20101209_AAAIZI evans_h_Page_021.jp2
4818c7a88c93e885f59ad4cf9d080369
9596b703fdb693428954ff9c0a488349c39d45b6
F20101209_AAAIYU evans_h_Page_005.jp2
30b6d8033a354c8c51910dbacd1622e8
144d90870c90e4a09c8a510462b269d6c3f9f133
515544 F20101209_AAAJFD evans_h_Page_184.jp2
0dbb612ed879d2808c2a60534226fd22
1f56c6351e4c25dbe7094663e1e4c06049a4a1dd
6012 F20101209_AAAKIG evans_h_Page_038thm.jpg
79ae86d9de774560c0c0c8d61a6aba5f
988a76ac21818868377f3d3635af267d852c9cd0
9621 F20101209_AAAKHR evans_h_Page_028.QC.jpg
964df66cc0218cd1f6bb2f670d705e62
27fc7b4e7f184db2da09801fa7077224f893c9a7
480600 F20101209_AAAJEP evans_h_Page_169.jp2
aee58617940820af9297155378c302ac
d5e46482f22f4a48acca66ea37cb8dc4c0f274c3
117337 F20101209_AAAIZJ evans_h_Page_022.jp2
f9f4bee2746938a83b43ba3dc8313dc1
c3440306e178f48a433ced79e9df026995c91170
F20101209_AAAIYV evans_h_Page_006.jp2
0a62b75a2943cb1709db6823922ce985
b6d552727e5435a4ae43e221aa2a06c00aeb66a5
1051961 F20101209_AAAJFE evans_h_Page_185.jp2
35a57b00ace7ebe4a6b332df1ee48955
a7f5ed51d5713f2d6b657dee08fea3afec5b6da9
22810 F20101209_AAAKIH evans_h_Page_038.QC.jpg
489e548d8e2a9bdea679573789c74f35
4fd1d19d8dae1d17bbba7d2c4ce243871fe066fc
5967 F20101209_AAAKHS evans_h_Page_029thm.jpg
b9a73dcb317ef96886a42f90cf488ca1
6d624ee7155266b7f87c8bede4d9ee9f35f14110
1050618 F20101209_AAAJEQ evans_h_Page_170.jp2
9157e8608305fbdabd2250028a938a7e
b11b9eb5608195cc65a305ce73aad0cc565d1b9a
117994 F20101209_AAAIZK evans_h_Page_023.jp2
af427e01f4585179c92f602ab15fe61c
57008dc9b107c00b5d57f5fe5901bbc01710aed4
F20101209_AAAIYW evans_h_Page_008.jp2
5781fc16c5b0936207ee8156fbd3e70d
65e372662a04913be042f75474fe99edfbfc823f
448829 F20101209_AAAJFF evans_h_Page_187.jp2
b3b843e158bef086b755fbc42e544008
a9dc853e695bc34a26e555f8a1048accb0742372
5614 F20101209_AAAKII evans_h_Page_039thm.jpg
263f0ec5863910fd2d01d1beb9c84aaa
f3707c95892d6445efcc709ba041f9d8a0384ca2
21075 F20101209_AAAKHT evans_h_Page_029.QC.jpg
7d7726ce06fe3fb9f43dc1593e228e09
378f97419da2a3d48a8515fc9c0bde13bc04c085
109128 F20101209_AAAJER evans_h_Page_171.jp2
09fa4790704fabf07a9583b126bab073
f42699d715c3fe5e59b9032de7288abd84c0fc5a
117878 F20101209_AAAIZL evans_h_Page_024.jp2
058fccdb01ce2b0fad8abda9a4cb3848
21defc01083cd195b3f9af4bb719d2f07f629f72
1051981 F20101209_AAAIYX evans_h_Page_009.jp2
e48961e4fdf7c79dc4005d1f8abd18c0
b2435ff2025bd88c18da560ad1672b2bd422f69a
813465 F20101209_AAAJFG evans_h_Page_188.jp2
51df238660301dbd164359ccd3aac85e
323f894c62dd7a1ea1ac4ddec7529cba507689c6
6266 F20101209_AAAKIJ evans_h_Page_040thm.jpg
f350df9b7392bafd808facb1f7307247
702b0f6f6e9731c44827d96978cef5e4fe1a7ae5
6041 F20101209_AAAKHU evans_h_Page_031thm.jpg
dabf8ee4c16f57060d97539718353a1e
266edf5c5fc8b7c76231b0f45a0eff11ca3ddd39
117607 F20101209_AAAJES evans_h_Page_172.jp2
c9860db17e2c218ce1f37014b4b17969
499f64121514d4d2c685cc51850607e2c0fba064
118722 F20101209_AAAIZM evans_h_Page_025.jp2
7eaf11eee416c3bf4e18e637b34a8992
24db6f030040dce70dfae370a6b79987c3f81b29
F20101209_AAAIYY evans_h_Page_010.jp2
ea0e6e1d877ad6e242a77ec9e7cca660
67c9009a7982e53e75785da1a0abf98c8b5497f2
117744 F20101209_AAAJFH evans_h_Page_189.jp2
a185a2990c23c3ee9ed93dfba59dd808
dece1c564926f9d71ad95777526ac3f4a58d501b
18946 F20101209_AAAKIK evans_h_Page_041.QC.jpg
e85d5fa0b260e65490a2918bd099d634
8df3be65c9caa1faa6cebe8abd60ab9257823440
22968 F20101209_AAAKHV evans_h_Page_031.QC.jpg
bacf1ae0eb5e1e27d2c6f82e8cb31266
2b2057dc1fd7acbd951d04a018ba921e4abd0987
116078 F20101209_AAAJET evans_h_Page_173.jp2
ad9d6d7e55f54c5829d3516d542e0f80
7a07c4252acafdc8d2d3a837117732b4530cb9ab
1051964 F20101209_AAAIZN evans_h_Page_026.jp2
98d689087707111c77d361c0b3924aa7
3c65063ae9882edc926f565801011de52d67b6fe
F20101209_AAAIYZ evans_h_Page_011.jp2
973fb8684d316fa9b63c5d260fac9326
860a7819accaeb3891bd6d87460ecc15a4b84f29
75131 F20101209_AAAJFI evans_h_Page_190.jp2
edfab930750ba1628378040c8efbb1c4
23c617de6e8ca2eb9eb7913d8d4f6f8893e4ad69
32951 F20101209_AAAKIL evans_h_Page_042.QC.jpg
25fb00035314cc08472b51ee599ee5d6
149bb98b26d2bfb0cb6672c650d9a6956bfa32a9
4139 F20101209_AAAKHW evans_h_Page_032thm.jpg
78a747f6a677a3ec7b53ba3219ad03d8
fb1ed36d826aae161cf04ba41d1fc1bd2a55ea06
117850 F20101209_AAAJEU evans_h_Page_174.jp2
8ef71a32b4577cd9c4821d77d7734443
ba3c1069322d95deef0b88c8434ac24c2777be5b
72597 F20101209_AAAIZO evans_h_Page_027.jp2
39ddfc769fadb96fac5164c12e49d8e6
f5a3e8933c8d898108ebc65268ab21a610d172cb
130397 F20101209_AAAJFJ evans_h_Page_191.jp2
13fa691da60e79a01dd208f00bee2fc3
214972a670511027a3e815b7d31bbc96ce6c2a75
37448 F20101209_AAAKJA evans_h_Page_055.QC.jpg
7ace3f8412dcf4082c1ba734d977d394
48669a6cad0aa58f29263292278de9eafbd7cb36
13311 F20101209_AAAKHX evans_h_Page_032.QC.jpg
d703758bf25092bf54e5bff165e584b6
a84d577be739a8c5137c0d9bdfc36f85fe7cb181
119668 F20101209_AAAJEV evans_h_Page_175.jp2
a986b158a3f54c35ddeb3b7731c77b81
e385a97e16de0c4d018398a7c61f9c28f7212d55
31987 F20101209_AAAIZP evans_h_Page_028.jp2
9c988291919f77dbb0b18df5fcdda6e5
1bd4a2741de4614099af7532b53cbfe70733af0e
8593 F20101209_AAAKJB evans_h_Page_056thm.jpg
9d9c009227f35dd7227d8b16b0128f2b
455288f6ddd5fac76afba3b5bddae59eb87156fd
8301 F20101209_AAAKIM evans_h_Page_044thm.jpg
6987190a2c1abe5eeb921b74579855a8
9bd7ca687b6f90af8f707bbb4b843964fc7209cb
23965 F20101209_AAAKHY evans_h_Page_033.QC.jpg
8ce14c4b15bd9448fd9fd88eb8193c93
1aaf99c3a9f693b711b958966bdc2eec92bf87eb
117843 F20101209_AAAJEW evans_h_Page_177.jp2
64521ca62fe75dcec75e75b74bccb2af
f5f358f4556e7960f4f9c9b0c33e1ca60dac579f
88213 F20101209_AAAIZQ evans_h_Page_029.jp2
81bcbc17c6b757850e96a69322bfc006
e243d7d5833335b62c7332705dde4748c2a709bd
148881 F20101209_AAAJFK evans_h_Page_192.jp2
716abc3cabbedf07ba1b67f828e710c9
392a55f5c507173b24a371f79104d7726f25b9e6
34700 F20101209_AAAKJC evans_h_Page_056.QC.jpg
38b333c7145686bc0f1e110328e66afc
4d17894163ca24f7c583d305fdf7ffcd2e76a23d
31963 F20101209_AAAKIN evans_h_Page_044.QC.jpg
a6d7206afec349ffb6a73f82696d4d51
744ee387fb646b4fcf50a34c53f72bab5f6c77db
5983 F20101209_AAAKHZ evans_h_Page_034thm.jpg
8a37a9cbad4ec6823aec9fc6477c7182
067daf1b32527dbc8dcbea779b0cfa4120e3fc46
120042 F20101209_AAAJEX evans_h_Page_178.jp2
f71730fe5e813d23e9bce5cfd702d6e2
5741837374be3d922a5c492af8d7c95bd4014639
114763 F20101209_AAAIZR evans_h_Page_030.jp2
fad25335f3ae90ae89be0d1792052fbd
c704ce148ba29c65c2970338b03f9723bfec6808
F20101209_AAAJGA evans_h_Page_005.tif
7f41b211490e0fafa24a98c08249126a
545b043d92f83b9314e3cc891fe983e660fce843
141477 F20101209_AAAJFL evans_h_Page_193.jp2
5cf492b932ae647df635572b245336be
a1c866598b6c3b122d967346904f4dd6a60e1516
8266 F20101209_AAAKJD evans_h_Page_057thm.jpg
2462a044a901743a2b3e5074c11352d8
b6d31ae95852b3b3a6be3665f3408b466d74a4da
25577 F20101209_AAAKIO evans_h_Page_045.QC.jpg
d08e5c96f481e43615dd0b88d945cd87
71855b3f496ffcc9f809055a23a597044951bebd
F20101209_AAAJEY evans_h_Page_179.jp2
73457786a22405d64e099450ba5f026a
68c1209a3b0c97a966917a277ad42027dfd5703a
86748 F20101209_AAAIZS evans_h_Page_031.jp2
a1f9e440f3ce5a9ab7315cb11437cf25
60b4bf212c608c7c1838ab0dc553a3f108c47fad
F20101209_AAAJGB evans_h_Page_006.tif
17c87eb3c9f9c129c91db13519f79ebb
37649ee62aa44a2df1aac523440dd60e69c6b7a3
138226 F20101209_AAAJFM evans_h_Page_194.jp2
b7e398f7b22c517fe833a5bb928f71d7
12a56efaf2ef2bfbe45efaa9c4d447f8722177a3
33687 F20101209_AAAKJE evans_h_Page_057.QC.jpg
bdf1fd0453a5de300ec2ae8bdccb838d
8116cca3a6d761496173b02eec4d709392ab0473
25242 F20101209_AAAKIP evans_h_Page_046.QC.jpg
868931c22da086ca29a42ae0e547dee3
ec7e2bac680094451d5bd1bb2cfab269c664cd2f
81143 F20101209_AAAJEZ evans_h_Page_180.jp2
2777cabcdb5bf1ae8d367f0134a940a1
db9607069b01b06bf7a33f0e645f93476dd83187
852038 F20101209_AAAIZT evans_h_Page_032.jp2
f2fbf7ea4185ec00185274246ceebc6e
8a9dcb1c0701dfb4792930719379416bda1203f2
F20101209_AAAJGC evans_h_Page_007.tif
fd2b796ba0681849743ef1d41a213992
54dd7d49d7ed979b1358d87be06876d56ca52e02
131478 F20101209_AAAJFN evans_h_Page_195.jp2
5a9412a08ce3f4d17f7a7a26ffeab9fa
098b998486a1e57434e06025ca2ff0286c4890da
6941 F20101209_AAAKJF evans_h_Page_058thm.jpg
3de82af251736a321225255d2bfad477
b39aab3bf99a7b9e61c2d5e0b6e9d73126242889
5854 F20101209_AAAKIQ evans_h_Page_047thm.jpg
fca285d4dce624c9e9691d76a36527fb
1942e0f1747ecf5fe841f39b737ba7599bdabec1
826439 F20101209_AAAIZU evans_h_Page_033.jp2
a15c50e9bc08547a46ad2d8ea9a6268e
6e34f05188295f7a58179c689122ed579821ba02
F20101209_AAAJGD evans_h_Page_008.tif
b43f23a51b2283e16473c8f42539f02c
699fea6a42e12e1642f9e69917e981414b8993b9
141822 F20101209_AAAJFO evans_h_Page_196.jp2
717e1f0caa24d3c79b35e8362ddfea8b
2462495dc417907b392780d253efe320e4574194
29482 F20101209_AAAKJG evans_h_Page_058.QC.jpg
f4764f4de6fc9014a488608942c98301
f33f549f177073034f300cfc43c9d38af5b8d1c7
22449 F20101209_AAAKIR evans_h_Page_047.QC.jpg
084243a6e5c93cb0dc5ffacd4a4e0d90
35b2d54b28b35ddd4fd58e2d4d3666ef1471f664
874186 F20101209_AAAIZV evans_h_Page_034.jp2
0ad9e8191764b06761717ac0931e2df2
c535c31c736a78376cb51e756ecc5d781d3e406e
F20101209_AAAJGE evans_h_Page_009.tif
5a61196d22999796d717461ab69d442b
80fb746ca85b484d92d88837154ed203e603491e
137578 F20101209_AAAJFP evans_h_Page_197.jp2
9b9eec90e67e59815789e424208629dd
c5f2a0c59aa874335533e362a20a7b7806b07040



PAGE 1

1MAGNETIC STRATIGRAPHY AND ENVIRONMENTAL MAGNETISM OF OCEANICSEDIMENTSByHELEN F. EVANSA DISSERTATION PRESENTED TO THE GRADUATE SCHOOLOF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENTOF THE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYUNIVERSITY OF FLORIDA2006

PAGE 2

2Copyright 2006byHelen F. Evans

PAGE 3

3For Jane and Eryl

PAGE 4

4ACKNOWLEDGMENTSI would like to thank my advisor, Jim Channell, for giving me the opportunity to study inFlorida and for all his help and support over the last 7 years. I also thank my committee membersEllen Martin, Neil Opdyke, John Jaeger and Bo Gustafson for agreeing to supervise my researchover the last five years and for all their help, academic and otherwise. I also had the pleasure ofcollaborating and interacting with a number of talented individuals without whose help I wouldnot have been able to accomplish this work: Gary Acton, Paul Bown, Yohan Guyodo, SeanHiggins, Claude Hillaire-Marcel, Dave Hodell, Kainian Huang, Mark Leckie, Ulla Rohl, JosephStoner, Ray Thomas, Thomas Westerhold and many others. My research was made possible bythe technical and financial support of several organizations including the National ScienceFoundation, the JOIDES U.S. Sciences Support Advisory Committee (USSAC), and theGraduate Student Council. Support was also provided by the Institute for Rock Magnetism, theCollege of Liberal Arts and Sciences, the Graduate School, the McLaughlin family, and thedepartment of Geological Sciences at the University of Florida.I thank all those who gave me their moral support during my years of study, which oftenconsisted of many hours of festivities in the numerous bars and restaurants in Gainesville, SanFrancisco and further afield. I thank in particular Gillian Rosen, Joe Graves, Joann and JasonHochstein, Howie Scher, George and Katherin Kamenov, Cara Gentry, Jen Mays, Steve Volpe,Phil DAmo, Bricky Way, Kendall Fountain, Adi Gilli, Simon Nielsen, Dave Hodell, MikeRosenmeier, William Kenney, Yohan Guyodo and Victoria Meija. Finally I would like toexpress my gratitude to my family without whose support I would not have been able tocomplete this work. I thank my late mother Eryl, my father Terry and my brother Michael. I alsothank Diane and John Thomas, Judy and Robin Ganz, and Molly and Reg Beynon.

PAGE 5

5TABLE OF CONTENTSpage ACKNOWLEDGMENTS...........................................................................................................4LIST OF TABLES......................................................................................................................7LIST OF FIGURES....................................................................................................................8ABSTRACT.............................................................................................................................12CHAPTER1INTRODUCTION.............................................................................................................142LATE MIOCENE-HOLOCENE MAGNETIC POLARITY STRATIGRAPHY ANDASTROCHRONOLOGY FROM ODP LEG 198-SHATSKY RISE...................................18Introduction.......................................................................................................................18Methods.............................................................................................................................19Magnetostratigraphic Interpretation....................................................................................20Astrochronology................................................................................................................23Discussion.........................................................................................................................24Conclusions.......................................................................................................................273INTEGRATED NEOGENE MAGNETIC, CYCLE AND BIOSTRATIGRAPHYFROM ODP SITE 1208 (SHATSKY RISE, PACIFIC OCEAN)........................................48Introduction.......................................................................................................................48Site Location and Lithology...............................................................................................51Magnetic Stratigraphy........................................................................................................51Cycle Stratigraphy.............................................................................................................53Calcareous Nannofossils....................................................................................................54Planktonic Foraminifera.....................................................................................................56Conclusions.......................................................................................................................584PALEOINTENSITY-ASSISTED CHRONOSTRATIGRAPHY OF DETRITALLAYERS ON THE EIRIK DRIFT (NORTH ATLANTIC) SINCE MARINE ISOTOPESTAGE 11.........................................................................................................................75Introduction.......................................................................................................................75Methods.............................................................................................................................76NRM and Normalized Remanence Record.........................................................................78Polarity Excursions.....................................................................................................79Relative Paleointensity................................................................................................79Chronology........................................................................................................................80Detrital Layer Stratigraphy.................................................................................................81

PAGE 6

6Discussion.........................................................................................................................84Conclusions.......................................................................................................................875RELATIVE PALEOINTENSITY STACK FOR THE LAST 85 KYR ON A REVISEDGISP CHRONOLOGY, AND ENVIRONMENTAL MAGNETISM OF THEGARDAR DRIFT............................................................................................................105Introduction.....................................................................................................................105Site Locations..................................................................................................................107Methods...........................................................................................................................108Directional Magnetic Data...............................................................................................110Normalized Remanence...................................................................................................111Stable Isotope Data and Age Models................................................................................112Bulk Magnetic and Physical Parameters...........................................................................112Relative Paleointensity Stack...........................................................................................113Environmental Magnetism...............................................................................................115Conclusions.....................................................................................................................1186RELATIVE GEOMAGNETIC PALEOINTENSITY IN THE GAUSS AND GILBERTCHRONS FROM IODP SITE U1313 (NORTH ATLANTIC).........................................136Introduction.....................................................................................................................136Methods...........................................................................................................................138Results.............................................................................................................................139Discussion.......................................................................................................................1427ODP SITE 1092 REVISED COMPOSITE DEPTH SECTION HAS IMPLICATIONSFOR UPPER MIOCENE "CRYPTOCHRONS"...............................................................161Introduction.....................................................................................................................161Revised Composite Depths (rmcd)...................................................................................162Implications for Magnetic Stratigraphy............................................................................1638ASTRONOMICAL AGES FOR MIOCENE POLARITY CHRONS C4AR-C5R (9.3-11.2 MA), AND FOR THREE EXCURSION CHRONS WITHIN C5N.2N.....................171Introduction.....................................................................................................................171Methods and Results........................................................................................................173Comparison with Other Timescales..................................................................................175Excursion Chrons.............................................................................................................1789CONCLUSIONS AND FUTURE WORK.......................................................................189LIST OF REFERENCES........................................................................................................191BIOGRAPHICAL SKETCH...................................................................................................204

PAGE 7

7LIST OF TABLESTable page 2-1Latitude, longitude, water depth....................................................................................282-2Magnetostratigraphic age model....................................................................................292-3Comparison of astrochronological age models...............................................................302-4Astrochronological ages for Leg 198.............................................................................313-1Depths of reversal boundaries from ODP Site 1208.......................................................593-2Astronomically calibrated ages for reversal boundaries from ODP Site 1208.................603-3Nannofossil datums for ODP Site 1208.........................................................................613-4Plio-Pleistocene foraminfer datums...............................................................................623-5Miocene foraminifer datums..........................................................................................634-1Core, latitude, longitude, water depth and base age of the core......................................894-2DC and LDC layer properties in Core MD99-2227........................................................904-3Detrital Layers from other studies considered to be correlative to detrital layersidentified on Eirik drift..................................................................................................915-1Summary of the cores used in this study and the eleven cores used in the relativepaleointensity stack.....................................................................................................1206-1Depth of polarity chrons from IODP Site U1313.........................................................1466-2Polarity reversal ages determined at Site U1313..........................................................1477-1Adjusted depths of core tops from ODP site 1092........................................................1667-2Position of the polarity zone boundaries at site 1092....................................................1678-1Astronomical ages from recent timescales compared with those inferred at ODP Site1092............................................................................................................................181

PAGE 8

8LIST OF FIGURESFigure page 2-1Bathymetric map of Shatsky Rise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2-2Representative orthogonal projections of AF demagnetization data...............................332-3Site 1207 component inclination and declination from discrete samples for 0-80meters...........................................................................................................................342-4Site 1207 component inclination and declination from discrete samples for 80-160meters...........................................................................................................................352-5Interval sedimentation rates and age versus depth..........................................................362-6Site 1209 component inclination and declination from discrete samples........................372-7Site 1210 component inclination and declination from discrete samples........................382-8Site 1211 component inclination and declination from discrete samples........................392-9Site 1212 component inclination and declination from discrete samples........................402-10Power spectra................................................................................................................412-11The astronomical solution for obliquity compared with tuned L* reflectance datafrom Site 1207...............................................................................................................422-12The astronomical solution for obliquity compared with tuned L* reflectance datafrom Site 1208...............................................................................................................432-13The astronomical solution for obliquity compared with tuned L* reflectance datafrom Site 1209...............................................................................................................442-14The astronomical solution for obliquity compared with tuned L* reflectance datafrom Site 1210...............................................................................................................452-15The astronomical solution for obliquity compared with tuned L* reflectance datafrom Site 1211...............................................................................................................462-16Cross-spectral analysis..................................................................................................473-1Bathymetric map showing the location of Shatsky Rise in the Pacific Ocean.................643-2Inclination, declination and MAD values plotted against meters below sea floor...........653-3Inclination, declination and MAD values.......................................................................66

PAGE 9

93-4Inclination, declination and MAD values.......................................................................673-5Orthogonal projections showing AF demagnetization data.............................................683-6Interval sedimentation rates...........................................................................................693-7Reflectance (L*) data....................................................................................................703-8Plio-Pleistocene planktonic foraminifer and calcareous nannofossil datums...................713-9Miocene planktonic foraminifer and calcareous nannofossil datums..............................723-10Calcareous nannofossil biostratigraphy..........................................................................733-11A proposed biostratigraphy for the mid-latitude North Pacific.......................................744-1Location map showing the Labrador Sea.......................................................................924-2Component inclination, corrected component declination and maximum angulardeviation.......................................................................................................................934-3Component inclination, declination and maximum angular deviation (MAD) valuesrecording Laschamp and Iceland Basin polarity excursions...........................................944-4Anhysteretic susceptibility (karm) plotted against volume susceptibility (k)....................954-5NRM, ARM, IRM and volume susceptibility.................................................................964-6JPC19: Relative paleointensity record correlated to that from ODP Site 983..................974-7JPC18: Relative paleointensity data correlated to ODP Site 983....................................984-8JPC15: Relative paleointensity data correlated to ODP Site 983....................................994-9MD99-2227: Relative paleointensity data correlated to ODP Site 983.........................1004-10karm/k and magnetic susceptibility versus age...............................................................1014-11Core MD99-2227: karm/k, magnetic susceptibility, bulk (GRAPE) density...................1024-12Photographs and X-radiographs of three detrital..........................................................1034-13Hysteresis ratios Mr/Ms plotted versus Hcr/Hc............................................................1045-1Location map for cores analyzed in this study..............................................................1215-2Correlation of the magnetic susceptibility records........................................................1225-3Orthogonal projections of alternating field demagnetization data.................................123

PAGE 10

105-4Component inclination, declination and maximum angular deviation (MAD) values...1245-5Plot of anhysteretic susceptibility (karm) versus volume susceptibility (k).....................1255-6Paleointensity proxies..................................................................................................1265-7Core JPC13 benthic oxygen isotope record..................................................................1275-8Relative paleointensity records from Cores JPC2, JPC5 correlated to Core JPC13.......1285-9Interval sedimentation rates for Cores JPC2, JPC5 and JPC13.....................................1295-10Core JPC13: GRA bulk density ..................................................................................1305-11Anhysteretic susceptibility divided by volume magnetic susceptibility........................1315-12Eleven relative paleointensity records from the North Atlantic Ocean..........................1325-13The new relative paleointensity stack..........................................................................1335-14Comparison of the EHC06 paleointensity stack to 36Cl flux.........................................1345-15Comparison of the EHC06 paleointensity stack...........................................................1356-1Location map for IODP Site U1313.............................................................................1486-2Magnetic polarity stratigraphy from IODP Site U1313 in the 120-200 mcd interval.....1496-3Magnetic polarity stratigraphy from IODP Site U1313 in the 200-280 mcd interval....1506-4Vector end-point projections of AF demagnetization data............................................1516-5Interval sedimentation rates.........................................................................................1526-6Gauss Chronozone at Site U1313................................................................................1536-7The magnetic grain size proxy, anhysteretic susceptibility divided by susceptibility....1546-8Later part of the Gilbert Chronozone at Site U1313.....................................................1556-9Relative paleointensity records from IODP Site U1313...............................................1566-10Volume magnetic susceptibility from u-channel samples.............................................1576-11Volume magnetic susceptibility from u-channel samples and L* reflectance datameasured shipboard.....................................................................................................1586-12Mean volume magnetic susceptibility..........................................................................1596-13Output of a gaussian filter centered on a period of 41 kyr............................................160

PAGE 11

117-1Fe intensity (XRF) data plotted as a five-point moving average...................................1687-2Inclination of the characteristic magnetization component...........................................1697-3Site 1092.....................................................................................................................1708-1Magnetic component inclination for the C4Ar.1n-C5r.1n interval................................1828-2Oxygen isotope records from the C4An-C5r.1n interval at ODP Site 1092..................1838-3Power spectrum generated from the oxygen isotope stack in the depth domain............1848-4Upper plot shows the correlation of the filtered (filter centered at 0.0244 0.0073kyr1) oxygen isotope stack to the astronomical solution for obliquity...........................1858-5Interval sedimentation rates for the C4Ar.1n-C5r.1n interval.......................................1868-6Comparison of the age estimates of polarity chrons at ODP Site 1092.........................1878-7The Site 1092 relative paleointensity record for C5n.2n...............................................188

PAGE 12

12Abstract of Dissertation Presented to the Graduate Schoolof the University of Florida in Partial Fulfillment of theRequirements for the Degree of Doctor of PhilosophyMAGNETIC STRATIGRAPHY AND ENVIRONMENTAL MAGNETISM OF OCEANICSEDIMENTSByHelen F. EvansDecember 2006Chair: James E. T. ChannellMajor: Geology This dissertation presents the results of chronostratigraphic studies on marine sediment cores from three Oceans. Using a combination of magnetic stratigraphy, biostratigraphy and cycle stratigraphy it is possible to produce chronostratigraphies that exceed the resolution of any individual technique. In the North Atlantic, environmental magnetic records from Eirik Drift, south of Greenland, record detrital signals related to the melting of the Greenland and Laurentide Ice Sheets. The detrital layer stratigraphy has been placed in a paleointensity-assisted chronostratigraphic template, based on paleointensity and stable isotope data, to enhance correlation of detrital layers across the North Atlantic region. In the central Atlantic, on Gardar Drift, correlation of a benthic oxygen isotope record to the Greenland and Vostok Ice cores has placed cores from the drift on a revised GISP chronology. A stack of relative paleointensity records was developed and placed on the revised GISP chronology. In marine isotope stage 3, a benthic isotope record appears to record changes in bottom water temperature that are coeval with magnetic grain size changes. IODP Site U1313 from the North Atlantic produced a high-resolution polarity stratigraphy and relative paleointensity record between 2.5 and 6.0 Ma. This is one of a handful

PAGE 13

13of paleointensity records for this interval. Cycles in magnetic susceptibility allowed age-calibration by correlation to a benthic oxygen isotope stack.Sediment cores from the Pacific Ocean produced excellent magnetic stratigraphies, andcycles in the sediment allowed astronomic calibration of reversal boundaries. Based on thecorrelation of planktonic foraminifer datums to the magnetic stratigraphy at ODP Site 1208, anew planktonic foraminifer zonation for the northwest Pacific Ocean can be precisely correlatedto polarity chrons and astronomically calibrated ages. Numerous paleomagnetic excursions aretentatively identified for the first time in Pacific sediments.Oxygen isotope records from the Late Miocene (9.3-11.2 Ma) at ODP Site 1092 (SouthAtlantic) allowed astronomic calibration of ages of reversal boundaries and three polarityexcursions within Chron 5. This is the first time astronomically calibrated ages have beenassigned to these polarity excursion chrons and indicate a duration for the excursions of 3-4 kyrs.

PAGE 14

14CHAPTER 1INTRODUCTIONStratigraphy is a fundamental part of Geology. Earth processes unfold over a great range oftime scales from millions of years to minutes and seconds. One of the challenges in stratigraphyis to be able to assign dates to events in the geologic record. The geologic timescale is the meansby which we can understand the history of the Earth and magnetic reversal stratigraphy providesthe central framework for the geologic timescale to which other dating techniques(biostratigraphic, radiometric, orbital) can be tied. This is because magnetic reversals are, ongeologic timescales, globally synchronous, environmentally independent events.The geomagnetic timescale of Heirtzler et al. (1968) was one of the foundations of theplate tectonic revolution. They proposed a geomagnetic polarity timescale for the LateCretaceous to Recent based on a few long magnetic anomaly profiles. The evolution of thepolarity timescale since 1968 has involved two types of revisions: adjustments of the relativespacing of some anomalies and calibration of the polarity sequence in time (Cande and Kent,1992). Over the past forty years the pattern of normal and reversed polarities has beenextensively studied and most of its large-scale features for the past 200 million years are nowwell understood (Gradstein et al., 2005).Classic magnetic polarity reversal stratigraphy lacks the resolution necessary for thehigh-resolution (millennial-scale) climate studies being conducted today. This led to thedevelopment of high-resolution cryogenic magnetometers capable of measuring whole-coresamples or u-channel samples. This in turn led to the development of "composite sections" formarine sediment cores whereby multiple cores were taken at a single site and spliced together toprovide a complete stratigraphic section (Hagelberg et al., 1995).

PAGE 15

15Changes in the intensity of the Earth's magnetic field occur over much shorter timescalesthan polarity reversals. These changes can be measured in sedimentary cores to produce recordsof relative geomagnetic paleointensity. This is done by normalizing the natural remanentmagnetization by an artificial remanence to remove intensity changes due to changes inconcentration of magnetic material in the core. Records of relative paleointensity have beenshown to be globally correlative on millennial timescales for the last glacial cycle (Laj et al.2004).In attempting to understand the time-depth relationship in marine sediment cores andtherefore understand more about the Earth's climate and evolution my work covers three Oceans,the South Atlantic, the North Atlantic and the Pacific. Below is a summary of the work presentedin this dissertation. The nature of this work is collaborative and, as such, data provided by mycolleagues is included in this dissertation. Their contribution is acknowledged and clearlydetailed in the following summary.In Chapter 2 magnetostratigraphic and cyclostratigraphic results are presented for the 0-12 Ma interval from sites drilled during ODP Leg 198 to Shatsky Rise. Cyclic alternations in thepercentage of calcium carbonate, as shown by color reflectance data and gamma ray attenuationbulk density measured on the sediments, allowed astronomic calibration of the magneticstratigraphy from six ODP Sites. This chapter was published in the Scientific Results Volume forOcean Drilling Program (ODP) Leg 198 (Evans et al., 2005). Chapter 3 is a continuation of thiswork and has produced an integrated magnetobioand cyclostratigraphy from ODP Site 1208for the 1-12 Ma interval. Biostratigraphic data included in this chapter were provided byNicholas Venti, Mark Leckie (U. Massachusetts, foraminifer) and Paul Bown (UniversityCollege London, nannofossils).

PAGE 16

16In Chapters 4 and 5, I used sedimentary relative paleointensity records to correlatebetween cores collected on drift deposits in the North Atlantic. In Chapter 4, I present a study ofsediments from the Eirik drift for the 0-400 ka interval. Detrital layers identified within fourcores are placed in a paleointensity assisted chronostratigraphic framework. Environmentalmagnetic records from climatically sensitive regions such as the North Atlantic can provideinformation about changes in the strength of bottom currents and ice sheet dynamics both ofwhich are climatically sensitive. Oxygen isotope data used in this chapter were provided by JimWright and Lauren Nietzke (Rutgers University) and Claude Hillaire-Marcel (GEOTOP) (CoreMD99-2227). This chapter is under review in the journal Geophysics, Geochemistry andGeosystems. In Chapter 5 cores from the Gardar Drift provide records of changes in magneticgrain size over glacial/interglacial and stadial/interstadial cycles for the last 130 ka. Thesechanges are interpreted as changes in the speed of bottom currents forming the drift deposits overglacial/interglacial cycles and stadial/interstadial cycles. David Hodell (UF) provided oxygenisotope data in Chapter 5.In Chapter 6 a paleomagnetic study of IODP Site U1313 from the North Atlantic ispresented. The magnetic stratigraphy spans the interval from 2.5-6.3 Ma including the Gauss andGilbert chronozones. A relative paleointensity record for the Gauss and Gilbert chrons, is one ofonly a handful of such records for this time interval. Cycles in magnetic susceptibility haveallowed astronomic calibration of the ages of reversal boundaries.In 2001, my MS thesis consisted of a paleomagnetic study of ODP Site 1092 from theSouth Atlantic. Chapter 7 presents a revision of the composite depth scale from ODP Site 1092.X-Ray fluorescence (XRF) scanning data were provided by Thomas Westerhold (UniversityBremen). This chapter was published in Geophysical Journal International (Evans et al. 2004).

PAGE 17

17In Chapter 8 we use cyclic alternations in a stack of three oxygen isotope records (Paulsen et al.,in press) from ODP Site 1092 in the South Atlantic to astronomically tune the magneticstratigraphy from 9.3-11.2 Ma. This includes the long normal polarity chron C5n.2n and threeshort reverse polarity intervals within it identified by Evans and Channell (2003). It also includesa critical age tie-point from the Cande and Kent (1995) Geomagnetic Polarity Timescale (GPTS)at the base of C5n.2n. This chapter is under review at Earth and Planetary Science Letters.

PAGE 18

18CHAPTER 2LATE MIOCENE-HOLOCENE MAGNETIC POLARITY STRATIGRAPHY ANDASTROCHRONOLOGY FROM ODP LEG 198-SHATSKY RISEIntroductionShatsky Rise is a medium-sized large igneous province in the west-Central Pacific Ocean(Figure 2-1) and is possibly the oldest existing oceanic plateau. The rise consists of threeprominent topographic highs. Sites 1209, 1210, 1211 and 1212 were cored on the Southern High(Bralower, Premoli Silva, Malone et al., 2002). Eight sites on the Southern High of the rise weredrilled during Deep Sea Drilling Project (DSDP) and earlier Ocean Drilling Program (ODP) legs(Sites 47, 48, 49, 50, 305, 306, 577, and 810). Of these, ODP Sites 577 and 810 providedinterpretable Neogene magnetic stratigraphies.Sites 1207 and 1208, from the Northern and Central Highs, provided unexpectedlyexpanded late Miocene (12.5 Ma) to Holocene sequences. These locations had not been coredduring previous DSDP/ODP expeditions. The initial age model for all of the sites was based oncorrelation of the sequence of polarity zones to the geomagnetic polarity timescale (GPTS)(Cande and Kent, 1992, 1995). Mean sedimentation rates at the five sites vary from 1to 4cm/k.y. Latitude and longitude of the sites and basal ages of the Neogene sediments are given inTable 2-1. Neogene sediments at the sites consisted mostly of light gray to pale orangenannofossil oozes with varying amounts of clay, radiolarians, and diatoms. Magneticsusceptibility is low (< 2 x10-5 SI) at all the sites and shows a decreasing trend from theQuaternary to the late Miocene. Composite sections were constructed shipboard for four of thesites (1209, 1210, 1211, and 1212) using multi-sensor track (MST) data including magneticsusceptibility, gamma ray attenuation (GRA) bulk density, and reflectance data. Sites 1207 and1208 were not double-cored, and depths at these sites are in meters below sea floor (mbsf). The

PAGE 19

19magnetic stratigraphy from the six sites (1207, 1208, 1209, 1210, 1211, and 1212), was based onshipboard pass-through magnetometer measurements and discrete samples measured post-cruise.Sediments from five of the sites (1207, 1208, 1209, 1210, and 1211) showed a prominentcyclicity in reflectance data for parts of the sections, and this is the basis for the construction ofan astronomically tuned age model for the 0to 8-Ma interval. The astronomically calibratedpolarity timescale has been well established for the 0to 6-Ma interval (Shackleton et al., 1990,1995; Hilgen 1991a, 1991b). Hilgen (1991a, 1991b) produced his astronomically calibratedpolarity timescale for the 2to 5.23-Ma interval using sapropel occurrences and carbonatecontent in Mediterranean sections. These polarity chron ages were incorporated into the GPTS ofCande and Kent (1995).In this study we produced an astronomically calibrated magnetic reversal stratigraphy forthe 0to 8-Ma interval. This is in good agreement with Hilgen (1991a, 1991b) and Shackleton etal., (1995) in the 0to 6-Ma interval. In the 6-to 8-Ma interval, polarity chron ages are in betteragreement with the Shackleton et al. (1995) timescale, differing by up to ~200 k.y. from that ofHilgen et al. (1995) and the ATNTS 2004 of Lourens et al. (2004). This chapter was published inthe Scientific Results Volume for ODP Leg 198 (Evans et al., 2005).MethodsTwo types of paleomagnetic measurements were made on sediments collected during ODPLeg 198; pass-through measurements on half-cores and discrete sample measurements. Discretesample cubes (2cm x 2cm) were collected during Leg 198 to augment measurements using theshipboard pass-through magnetometer. Shipboard measurements on half-cores were made at 5-cm intervals. A total of 747 discrete samples were taken at 50-cm intervals. Discrete sampleswere collected from the center of the half-cores to avoid deformation at the outer edges of thecore. Magnetic measurements on the cubes were performed in the magnetically shielded room at

PAGE 20

20the University of Florida using a 2G-Enterprises cryogenic magnetometer. The samples werestep-wise alternating-field (AF) demagnetized using a D-Tech D2000 AF demagnetizer.Magnetization component directions were determined using the method of Kirschvink (1980),applied to the 20to 60 mT peak field demagnetization interval.The astrochronology developed for Sites 1207, 1208, 1209, 1210, and 1211 was based oncycles seen in reflectance data (L*) measured shipboard on a purpose-built track. Reflectance ofvisible light from soft sediment cores was measured using a spectrophotometer at 2.5-cmintervals and provided a high-resolution record of color variations for visible wavelengths (400-700 nm). L* reflectance represents "lightness" of the sediment which is usually controlled bychanges in percent carbonate.The initial age model for each site was based on correlation of the polarity zone sequenceto the timescale of Cande and Kent (1995). Power spectra using the Blackman-Tukey methodwith a Bartlett window from the Analyseries software of Paillard et al. (1996) indicate thepresence of obliquity and eccentricity peaks. The reflectance data were then tuned to theastronomic solutions for obliquity from Laskar et al. (1993). This allowed astronomicallycalibrated ages to be assigned to the polarity reversal boundaries at Sites 1207, 1208, 1209, 1210and 1211. Site 1212 was not included in the astrochronology, as it contains a hiatus at 4to 5-Ma.Magnetostratigraphic InterpretationSite 1207 is the only site that has been drilled on the Northern High of Shatsky Rise. Thesequence of sediment recovered was mostly Neogene in age (0-163.8 mbsf) underlain byCampanian and older oozes and cherts. The sediment consists of nannofossil ooze with diatoms,radiolarians, and clay in varying amounts (Bralower, Premoli Silva, Malone et al., 2002). Thesamples taken for paleomagnetic analysis were AF demagnetized in 5-mT steps up to either 50,

PAGE 21

2160, or 70 mT, depending on the intensity of the natural remanent magnetization (NRM). Lessthan 10% of the NRM remains after demagnetization at these peak fields, indicating a low-coercivity remanence carrier, most likely magnetite. Orthogonal projections of demagnetizationdata (Figure 2-2) show well-defined components for most of the Neogene section after removalof the steep drilling related overprint at peak AF fields of 20 mT. Maximum angular deviation(MAD) values are low for most of the section (< 10), indicating well-defined characteristicmagnetization components; however, some intervals, particularly the interval between 50-60mbsf (Figure 2-3), have slightly higher MAD values and less well-defined components. Theinterpretation of the magnetic stratigraphy from shipboard and discrete sample data can beaccomplished by polarity zone pattern fit to the GPTS (Cande and Kent, 1992, 1995) (Table 2-2).This pattern fit is satisfactory to the base of Subchron C5An.1n (Figures 2-3, 2-4). Below thepolarity zone equivalent to Subchron C5An.1n, recovery was intermittent and biostratigraphyindicates a hiatus with Campanian age sediments below (Bralower, Premoli Silva, Malone et al.,2002). Sedimentation rates average 1-2 cm/k.y. throughout the section with some slightly higher(3-4 cm/k.y.) rates in the late Pliocene and late Miocene (Figure 2-5A). Component declinationhas been corrected for each core using Tensor orientation data measured shipboard. The meaninclination in normal polarity zones for the Site is 57.8, close to the expected inclination of 56for a geocentric axial dipole at this site; however, reversed polarity intervals have a meaninclination of -51.1, shallower than expected. This can be attributed to shallowing of reversedpolarity directions by the steep downward-directed drilling overprint, shown clearly in theorthogonal projections (Figure 2-2A).Sites 1209, 1210, 1211, and 1212 are located on the southern high of Shatsky Rise(Figure 2-1). Multiple holes were drilled at each site and composite sections were constructed

PAGE 22

22using shipboard MST data. Discrete sample cubes were only collected from Holes 1209A,1210A, 1211A, and 1212A. The shipboard data from the pass-through magnetometer areconsistent between the different holes at each site and confirms the interpretation of the magneticstratigraphy (see Shipboard Scientific Party, 2002).As for Site 1207, orthogonal projections from discrete sample data show two components:-a steep downward drilling related overprint and well-defined characteristic components (Figure2-2 B, C, D, E). In most cases the drilling related overprint was easily removed in peak AF fieldsof 10-20 mT. Little of the natural remanent magnetization remained at peak fields of 60 mT.MAD values are generally <5 throughout the sections. The expected inclination for theSouthern Rise is 51; again, all the sites show slightly steeper than expected inclinations innormal polarity zones and shallower than expected inclination in reversed polarity zones. Themagnetostratigraphic age models indicate mean sedimentation rates between 1and 3 cm/k.y. formost of the Neogene (Figure 2-5 B, C, D, E).The polarity interpretation at Sites 1209, 1210, and 1211 is unambiguous back to SubchronC3Bn (Table 2-2) (Figures 2-6, 2-7, 2-8). Below this level, interpretation becomes difficult dueto decreasing sedimentation rates leading to a hiatus recognized at all sites between the upperMiocene, and Oligocene and older sequences. At Site 1212, a hiatus accounts for the intervalbetween 4 and 5 Ma (Chron C3), and the polarity interpretation can be accomplished toSubchron C4n.2n (Figure 2-9). This interpretation of the sequence of polarity zones is confirmedby the shipboard biostratigraphy. The interpretation of the polarity stratigraphy was carried outusing data measured shipboard augmented with discrete sample cubes. When themagnetostratigraphic data were placed on the composite depth scale, the reversal boundarieswere found to be consistent between holes, indicating that there is very little error in the depths

PAGE 23

23of polarity zone boundaries or in composite depth calculations. The magnetic measurementsmade shipboard do include a small amount of error due to the response function of the shipboardmagnetometer. The response function of the wide-access magnetometer used to measure half-cores is ~10 cm, resulting in a cm-scale uncertainty in the placement of the reversal boundaries.Site 1208 is located on the Central High of Shatsky Rise and also provided an expandedlate Miocene to Holocene section. The magnetic stratigraphy from Site 1208 will be presented inChapter 3.AstrochronologyCycles were visually identifiable in L* reflectance data from all six of the sites in thisstudy. For Sites 1209, 1210, and 1211, we worked with spliced composite records rather thandata from a single hole. Reflectance data were initially placed on the magnetostratigraphic agemodel based on the polarity timescale of Cande and Kent (1995). Power spectra for untunedsections of reflectance data placed on this age model consistently show a concentration of powerat orbital frequencies, particularly around the 41 k.y. obliquity cycle (Figure 2-10).The reflectance records were then tuned to the astronomical solution for obliquity fromLaskar et al. (1993), as this was the most visually identifiable cycle in the reflectance data andthe power spectra for different time intervals in all the sites showed a concentration of power atthe obliquity frequency (Figure 2-10). In constructing the astrochronological age model, weassume that there was no phase lag between the orbital forcing and the response. Forconvenience, the reflectance data were broken up into 1 Myr intervals when compared to theastronomical solution and each site was tuned independently. Cycles were readily apparent in thereflectance data for all sites, and tuning of the record required a minimum of adjustment of peaksin the reflectance data to the astronomical solution (Figures 2-11, 2-12, 2-13, 2-14).Astronomically tuned ages were calculated for polarity reversals in the 1 to 8-Ma interval at Site

PAGE 24

241207 (Table 2-3). At Site 1209, tuning was performed in the 1 to 7-Ma interval and at Sites 1210and 1211 in the 1 to 5-Ma interval. Site 1208 has also provided an astrochronological age modelfor the 1 to 6-Ma interval (Figure 2-12) and is included in Table 3. The tuned age models arecompared to each other (Table 2-3) and are compared with other recently publishedastrochronologies for this time period (Table 2-4). The output of a band-pass filter centered on41 k.y. is shown below the astronomical solution for obliquity and the raw reflectance data inFigures 2-11, 2-12, 2-13, 2-14, and 2-15.To test the validity of the timescale we used cross-spectral analysis performed using theBlackman-Tukey method and Analyseries software (Paillard et al., 1996). Coherence betweenthe reflectance data and the astronomical solution for obliquity was significant at all the sites,although the coherence values depend on which time interval is being examined. At Site 1207coherence was ~ 0.8 for the 1.2 to 1.8-Ma and 6.2 to 6.8-Ma intervals (Figure 2-16A). Thecoherence values at Site 1208 were > 0.8 for the entire 1 to 6-Ma interval. Sites 1209, 1210, and1211 also showed coherence values between 0.8 and 1 (Figure 2-16C, 2-16D, 2-16E).DiscussionComparison of the tuned ages for polarity reversal boundaries at the five sites in the 1.5to 2-Ma interval showed that polarity chron ages are in good agreement. For other time intervalsthere are some significant differences (more than an obliquity cycle) between sites (Table 2-3).Intervals with enhanced 41 k.y. power in reflectance data are considered more reliable (italics inTable 2-3). Site 1208 showed the strongest cyclicity, with Site 1207 also showing a clear signalin some intervals particularly the 2.1 to 2.7-Ma and 4.5 to 5-Ma intervals.During ODP Leg 138 to the eastern equatorial Pacific, 11 sites were drilled and most ofthem showed a prominent cyclicity in GRA density. Shackleton et al. (1995) used these cycles inGRA bulk density records to produce an orbitally-tuned age model for the 0 to 12.5-Ma interval.

PAGE 25

25They worked entirely in the time domain comparing smoothed GRA bulk density records withthe target record of summer insolation at 65N. In their tuning they assumed that no phase lagexisted between insolation and GRA bulk density controlled by proportion of SiO2 and CaCO3(high density), high carbonate content being associated with high Northern Hemisphereinsolation. Age control points were added to the data to align prominent groups of densitymaxima. The records were broken into 0.8-m.y. intervals for convenient viewing. Each site wastuned independently over the chosen time interval. Shackleton et al. (1995) found that someintervals in these records were more easily tuned than others, similar to results from Leg 198.Shackleton et al. (1995) noted that it was difficult to tune the 0to 1-Ma interval, which was alsothe case at four of the Leg 198 Sites (1208, 1209, 1210, and 1211). The 1to 2-Ma interval forthe Leg 138 sites carries a clear 41 k.y. obliquity cycle. For Leg 198 sites, the 1.2to 1.6-Mainterval also carries a very clear obliquity cycle (Figures 2-11, 2-12, 2-13, 2-14, 2-15). In the 2.4-to 2.6-Ma interval, a very strong obliquity cycle was observed at Site 846 (Leg 138), and thissame interval also carries a strong 41 k.y. signal at Sites 1209, 1210, and 1211. Comparisonbetween the Site 1207 age model and ages from Shackleton et al. (1995) indicate consistency forthe 1-to 8-Ma time interval (Table 2-4).Hilgen et al. (1995) developed an astronomical timescale for the interval from 3to 9.7-Mausing lithologic cyclicity seen in sedimentary sections in the Mediterranean. These sectionscomprise open marine sediments that alternate between carbonate-rich and carbonate-poor marlsor homogeneous marls and sapropels. The individual sapropels were related to precessionminima, and the clusters of sapropels to the 400-k.y. eccentricity cycles. In tuning the section,the target curve used was the 65N summer insolation curve. To obtain an astronomical age forthe youngest polarity reversal in the sequence, Hilgen et al. (1995) took the Shackleton et al.

PAGE 26

26(1995) age for the onset of Subchron C3An.2n of 6.576 Ma. They then matched the lithologiccycles in the section to the astronomical solution using the correlation of sapropel clusters toeccentricity. The age of the calibration point (6.576 Ma) had to be adjusted to 100 k.y. older toestablish a consistent correlation between sapropel clusters and eccentricity maxima. The agesfrom Hilgen et al. (1995) differ significantly with those from Leg 198 in the 6-to 8-Ma interval(Table 4). At the top of Subchron C3Bn the difference is more than 200 k.y. In the interval from7.2to 8.1-Ma, the difference is ~ 100 k.y. which is the amount of adjustment of the 6.576-Matie point used by Hilgen et al. (1995) for the age of the youngest polarity reversal in their section.ODP Site 926 on the Ceara Rise also produced an orbitally tuned timescale from 5to 14-Ma (Shackleton and Crowhurst, 1997). This timescale cannot be directly compared with the Leg198 timescale because of a lack of polarity reversals at Site 926. Backman and Raffi (1997) usedthe cyclostratigraphic age model from Site 926 to calibrate ages of the calcareous nannofossildatums for the late Miocene. These ages were then compared with the biomagnetochronologyfrom Site 853 (ODP Leg 138). The center of the peak in abundance of transitional morphotypesof Triquetrorhabdulus rugosus at Site 853 occurred 120-130 k.y. after the corresponding peak atSite 926. The age estimates of Hilgen et al. (1995) were then applied to the Site 853 data and thepeak center was found to coincide at Sites 853 and 926. Therefore, Backman and Raffi (1997)considered that the Hilgen et al. (1995) ages are more reliable in this interval than the ages ofShackleton et al. (1995).Lourens et al. (2004) have recalibrated the Miocene astronomic timescales of Shackletonand Crowhurst (1997) and Hilgen et al. (1995) using the astronomic solution of Laskar et al.(2004). For the last 13 Ma the retuning resulted in almost negligible changes in the ages ofreversal boundaries (Lourens et al., 2004). For the 6to 8Ma interval the ATNTS2004 is in

PAGE 27

27close agreement with that of Hilgen et al (1995) and therefore differs significantly with theresults of this study.ConclusionsFive sites from Shatsky Rise have produced high-quality magnetic stratigraphies from thelate Miocene to Holocene. Cycles identified in reflectance data from Sites 1207, 1208, 1209,1210, and 1211 have allowed astronomic calibration of the polarity reversal sequence from ~8Ma to present. The assumption that there is no phase lag between sedimentary cyclicity and theastronomical parameters allowed the cycles to be tuned to the astronomical solution forobliquity. Cross-spectral analysis on the tuned age model indicated high coherence between theastronomic solution and the reflectance data and confirms the reliability of the tuning. The agemodel has been compared with other published astrochronologies and is found to be in goodagreement with Hilgen (1991a, 1991b) (and, therefore, Cande and Kent [1995]) in the 1-to 6-Mainterval. In the 6-to 8-Ma interval the age model differs significantly from that of Lourens et al.(in press) and Hilgen et al. (1995) from the Mediterranean. It is in better agreement with theODP Leg 138 timescale of Shackleton et al. (1995) from the Pacific Ocean.

PAGE 28

28Table 2-1. Latitude, longitude, water depth, the oldest Neogene magnetic polarity chronidentified, and the basal age of the Neogene section. Site Latitude Longitude Waterdepth Basal Chron Basal Age(Ma) 1207 37.4287' N 162.0530'E 3100m C5An2n 12.184 1209 32 39.1001'N 158.3560'E 2387m C3Bn 7.091 1210 32 13.4123'N 158.5618'E 2573m C3Bn 7.091 1211 32 0.1300'N 157.9999'E 2907m C3Bn 7.091 1212 32 26.9000'N 157.7016'E 2682m C4n.2n 8.072

PAGE 29

29Table 2-2. Magnetostratigraphic age model for Sites 1207, 1209, 1210, 1211 and 1212. Polaritychron labels are according to Cande and Kent (1992, 1995). Ages of chrons are fromCande and Kent (1995). Depths are in meters below sea floor (mbsf) for Site 1207and meters composite depth (mcd) for Site 1209, 1210, 1211 and 1212. Chron Ma (CK95) 1207 (mbsf) 1209 (mcd) 1210 (mcd) 1211 (mcd) 1212 (mcd) C1n 0.00 0.00 0.00 0.00 0.00 0.00 base 0.780 12.35 11.28 14.89 8.00 11.95 C1r.1n 0.990 16.26 13.32 18.07 9.550 14.12 base 1.070 16.77 14.22 19.71 10.27 14.98 C2n 1.770 24.38 25.28 32.03 16.74 23.62 base 1.950 28.40 28.21 34.70 18.38 25.78 C2r.1n 2.197 29.73 37.68 23.70 26.95 base 2.229 30.25 38.09 30.08 27.78 C2An.1n 2.581 43.13 37.69 46.51 30.90 32.61 base 3.040 51.77 49.43 56.88 32.34 39.00 C2An.2n 3.110 53.25 58.52 33.98 39.81 base 3.220 56.79 60.37 37.37 41.67 C2An.3n 3.330 58.77 52.34 61.81 41.17 43.00 base 3.580 66.91 58.03 67.35 42.51 48.68 C3n.1n 4.180 80.23 66.22 75.36 43.94 base 4.290 83.34 68.23 77.62 44.66 C3n.2n 4.480 87.19 80.90 46.92 base 4.620 90.46 82.34 49.28 C3n.3n 4.800 92.39 73.24 83.78 50.72 base 4.890 94.32 74.08 85.42 51.70 C3n.4n 4.980 96.84 75.59 86.45 52.69 base 5.230 99.95 78.76 91.17 53.80 C3An.1n 5.894 105.73 82.94 94.05 54.29 54.44 base 6.137 106.77 84.95 95.69 55.15 56.17 C3An.2n 6.269 109.29 86.12 97.02 58.31 base 6.567 114.18 90.13 99.12 59.14 C3Bn 6.935 116.56 93.81 100.35 59.88 base 7.091 120.41 96.15 101.46 61.03 C3Br.1n 7.135 61.60 base 7.170 63.58 C3Br.2n 7.341 123.08 64.57 base 7.375 123.53 65.14 C4n.1n 7.432 125.16 65.39 base 7.562 126.05 66.95 C4n.2n 7.650 126.34 67.37 base 8.072 129.01 70.00 C4r.1n 8.225 130.79 base 8.257 132.27 C4An 8.699 134.50 base 9.025 136.72 C4Ar.1n 9.23 137.76 base 9.308 138.35 C4Ar.2n 9.580 140.28 base 9.642 140.72 C5n.1n 9.740 141.32 base 9.880 142.36 C5n.2n 9.920 142.65 base 10.949 151.40 C5r.1n 11.052 153.62 base 11.099 154.07 C5r.2n 11.476 155.11 base 11.531 155.40 C5An.1n 11.935 157.81 base 12.078 160.77 C5An.2n 12.184 161.76 base 12.401

PAGE 30

30Table 2-3. Comparison of astrochronological age models for sites 1207, 1208, 1209, 1210 and1211. Italics indicate the most reliable ages in intervals where the cyclicity inreflectance is best defined. In italics and brackets are the differences between tunedages and those of Cande and Kent (1995). Chron Ka(CK95)(Hilgen1991a,b) Site 1207Ka(difference) Site 1208Ka(difference) Site 1209Ka(difference) Site 1210Ka(difference) Site 1211Ka(difference) C1n 0 0 C1r.1r 780 776.7 (-3.3) C1r.1n 990 992.8 (2.8) C1r.2r 1070 1089.4 (19.4) 1073.9 (3.9) 1069.4 (-0.6) C2n 1770 1786.4 (16.4) 1776.2 (6.2) 1770.0 (0) 1777.8 (7.8) 1777.8 (7.8) C2r.1r 1950 1954.2 (4.2) 1948.7 (-1.3) 1975.4 (25.4) 1972.2 (22.2) 1972.2 (22.2) C2r.1n 2140 2095.7 (-44.3) 2133.5 (-6.5) C2r.2r 2150 2112.0 (-38) 2170.4 (20.4) C2An.1n 2581 2620.5 (39.5) 2564.7 (-16.3) 2550.3 (-30.7) 2642.7 (61.7) 2536.1 (-44.9) C2An.1r 3040 3042.5 (2.5) 3045.2 (5.2) 3032.0 (-8) 3032.9 (-7.1) 3022.2 (-17.8) C2An.2n 3110 3118.0 (8) 3105.8 (-4.2) 3114.9 (4.9) 3110.9 (0.9) C2An.2r 3220 3236.5 (16.5) 3229.8 (9.8) 3248.5 (28.5) 3242.3 (22.3) C2An.3n 3330 3354.5 (24.5) 3340.9 (10.9) 3361.4 (31.4) 3340.5 (10.5) 3352.8 (22.8) C2Ar 3580 3593.3 (13.3) 3599.6 (19.6) 3648.8 (68.8) 3597.5 (17.5) 3644.4 (64.4) C3n.1n 4180 4154.0 (-26) 4190.9 (10.9) 4172.5 (-7.5) 4182.8 (2.8) 4169.4 (-10.6) C3n.1r 4290 4262.5 (-27.5) 4351.9 (61.9) 4305.9 (43.4) 4305.9 (15.9) 4305.6 (15.6) C3n.2n 4480 4489.8 (9.8) 4523.6 (43.6) 4501.0 (21) 4457.9 (-22.1) C3n.2r 4620 4637.0 (17) 4683.8 (63.8) 4665.3 (45.3) 4589.3 (-30.7) C3n.3n 4800 4760.5 (-39.5) 4806.9 (6.9) 4809.0 (9) 4798.8 (-1.2) C3n.3r 4890 4857.3 (-32.7) 4880.9 (-9.1) 4880.9 (-9.1) 4891.2 (1.2) C3n.4n 4980 4972.5 (-7.5) 4991.8 (11.8) 4981.5 (1.5) 4973.3 (-6.7) 4950.7 (-29.3) C3r 5230 5245.4 (15.4) 5201.2 (-28.8) 5240.2 (10.2) C3An.1n 5894 5886.0 (8) 5952.7 (58.7) 5915.8 (21.8) C3An.1r 6137 6143.0 (6) 6073.9 (36.9) C3An.2n 6269 6241.5 (-27.5) 6318.3 (49.3) C3Ar 6567 6526.2 (-40.8) 6548.3 (-18.7) C3Bn 6935 6878.0 (-57) 6971.3 (35.3) C3Br.1r 7091 7095.8 (4.8) 7027.7 (-63.3} C3Br.1n 7135 C3Br.2r 7170 C3Br.2n 7341 7348.2 (8.2) C3Br.3r 7375 7388.3 (13.3) C4n.1n 7432 7453.5 (3.5) C4n.1r 7562 7540.9 (-21.1) C4n.2n 7650 7634.1 (15.9) C4r.1r 8072 8038.0 (-34)

PAGE 31

31Table 2-4. Astrochronological ages for Leg 198 compared to ages Hilgen (1991a, 1991b), Hilgenet al. (1995) and Shackleton et al, (1995). In italics and brackets are the differencesbetween Leg 198 tuned ages and Hilgen et al. (1995) and Shackleton et al. (1995). Chron Ka (CK95)Hilgen(1991a,b) Leg 198 Shackletonet al. (1995)(differenceto 198) Hilgen et al.(1995a)(differenceto 198) C1n 0 base 780 776.7 C1r.1n 990 992.8 base 1070 1089.4 C2n 1770 1786.4 base 1950 1954.2 C2r.1n 2140 2133.5 base 2150 2170.4 C2An.1n 2581 2564.7 base 3040 3042.5 3046 (3.5) C2An.2n 3110 3118.0 3131 (13) base 3220 3236.5 3233 (-3.5) C2An.3n 3330 3354.5 3331 (-23.5) base 3580 3593.3 3594 (0.7) C3n.1n 4180 4190.9 4199 (8.1) base 4290 4351.9 4316 (-35.9) C3n.2n 4480 4523.6 4479 (-44.6) base 4620 4683.8 4623 (-60.8) C3n.3n 4800 4806.9 4781 (-25.9) base 4890 4880.9 4878 (-2.9) C3n.4n 4980 4972.5 4977 (4.5) base 5230 5201.2 5232 (30.8) C3An.1n 5894 5952.7 5875 (-77.7) base 6137 6143.0 6122 (-21) C3An.2n 6269 6241.5 6256 (14.5) base 6567 6526.2 6555 (28.8) 6677 (150.8) C3Bn 6935 6878.0 6919 (41) 7101 (223) base 7091 7095.8 7072 (-23.8) 7210 (114.2) C3Br.1n 7135 7256 base 7170 7301 C3Br.2n 7341 7348.2 7455 (106.8) base 7375 7388.3 7492 (103.7) C4n.1n 7432 7453.5 7406 (-47.5) 7532 (78.5) base 7562 7540.9 7533 (-7.9) 7644 (103.1) C4n.2n 7650 7634.1 7618 (-16.1) 7697 (62.9) base 8072 8038.0 8027 (-11) 8109 (71)

PAGE 32

32 Figure 2-1. Bathymetric map of Shatsky Rise showing the location of sites drilled during ODPLeg 198.

PAGE 33

33 Figure 2-2. Representative orthogonal projections of AF demagnetization data from (A) Site1207, (B) Site 1209, (C) Site 1210, (D) Site 1211 and (E) Site 1212. Low AFdemagnetization treatment and the high treatment are given, as is mbsf or mcd of thesample. Open circles represent the vector end-point projection on the vertical plane,while closed circles represent the vector endpoint projection on the horizontal plane.

PAGE 34

34 Figure 2-3. Site 1207 component inclination and declination from discrete samples (opensquares) for 0-80 meters. Inclination and rotated declination from the shipboard pass-through magnetometer after AF demagnetization at peak fields of 20 mT (gray line).Chrons are labeled according to Cande and Kent (1992). Black indicates normalpolarity, white reversed polarity. Also shown are the MAD values calculated fordiscrete sample data (after Kirschvink, 1980).

PAGE 35

35 Figure 2-4. Site 1207 component inclination and declination from discrete samples (opensquares) for 80-160 meters. Inclination and rotated declination from the shipboardpass-through magnetometer after AF demagnetization at peak fields of 20 mT (grayline). Chrons are labeled according to Cande and Kent (1992). Black indicates normalpolarity, white reversed polarity. Also shown are the MAD values calculated fordiscrete sample data (after Kirschvink, 1980).

PAGE 36

36 Figure 2-5. Interval sedimentation rates and age versus depth for the initial age model at a) Site1207, b) Site 1209, c) Site 1210, d) Site 1211 and e) Site 1212.

PAGE 37

37 Figure 2-6. Site 1209 component inclination and declination from discrete samples (opensquares). Inclination and rotated declination from the shipboard pass-throughmagnetometer after AF demagnetization at peak fields of 20 mT (gray line). Chronsare labeled according to Cande and Kent (1992). Black indicates normal polarity,white reverse polarity. Also shown are the MAD values calculated for discrete sampledata (after Kirschvink, 1980).

PAGE 38

38 Figure 2-7. Site 1210 component inclination and declination from discrete samples (opensquares). Inclination and rotated declination from the shipboard pass-throughmagnetometer after AF demagnetization at peak fields of 20 mT (gray line). Chronsare labeled according to Cande and Kent (1992). Black indicates normal polarity,white reverse polarity. Also shown are the MAD values calculated for discrete sampledata (after Kirschvink, 1980).

PAGE 39

39 Figure 2-8. Site 1211 component inclination and declination from discrete samples (opensquares). Inclination and rotated declination from the shipboard pass-throughmagnetometer after AF demagnetization at peak fields of 20 mT (gray line). Chronsare labeled according to Cande and Kent (1992). Black indicates normal polarity,white reverse polarity. Also shown are the MAD values calculated for discrete sampledata (after Kirschvink, 1980).

PAGE 40

40 Figure 2-9. Site 1212 component inclination and declination from discrete samples (opensquares). Inclination and rotated declination from the shipboard pass-throughmagnetometer after AF demagnetization at peak fields of 20 mT (gray line). Chronsare labeled according to Cande and Kent (1992). Black indicates normal polarity,white reverse polarity. Also shown are the MAD values calculated for discrete sampledata (after Kirschvink, 1980).

PAGE 41

41 Figure 2-10. Power spectra from a) Site 1207, b) Site 1208 c) Site 1209, d) Site 1210, and e) Site1211 for reflectance data placed on a Cande and Kent (1995) age model.

PAGE 42

42 Figure 2-11. The astronomical solution for obliquity (Laskar et al., 1993) compared with tunedL* reflectance data from Site 1207 for the 0-8 Ma interval. The reflectance datafiltered using a band-pass filter centered on 41kyrs is shown in the lower part of eachframe. Black indicates normal polarity and white reverse polarity. Heavy line on L*reflectance data indicates intervals where the cyclicity is best developed.

PAGE 43

43 Figure 2-12. The astronomical solution for obliquity (Laskar et al., 1993) compared with tunedL* reflectance data from Site 1208 for the 1-6 Ma interval. The reflectance datafiltered using a band-pass filter centered on 41kyrs is shown in the lower part of eachframe. Black indicates normal polarity and white reverse polarity. Heavy line on L*reflectance data indicates intervals where the cyclicity is best developed.

PAGE 44

44 Figure 2-13. The astronomical solution for obliquity (Laskar et al., 1993) compared with tunedL* reflectance data from Site 1209 for the 1-7 Ma interval. The reflectance datafiltered using a band-pass filter centered on 41kyrs is shown in the lower part of eachframe. Black indicates normal polarity and white reverse polarity. Heavy line on L*reflectance data indicates intervals where the cyclicity is best developed.

PAGE 45

45 Figure 2-14. The astronomical solution for obliquity (Laskar et al.,, 1993) compared with tunedL* reflectance data from Site 1210 for the 1-5 Ma interval. The reflectance datafiltered using a band-pass filter centered on 41kyrs is shown in the lower part of eachframe. Black indicates normal polarity and white reverse polarity. Heavy line on L*reflectance data indicates intervals where the cyclicity is best developed.

PAGE 46

46 Figure 2-15. The astronomical solution for obliquity (Laskar et al., 1993) compared with tunedL* reflectance data from Site 1211 for the 1-5 Ma interval. The reflectance datafiltered using a band-pass filter centered on 41 kyrs is shown in the lower part of eachframe. Black indicates normal polarity and white reverse polarity. Heavy line on L*reflectance data indicates intervals where the cyclicity is best developed.

PAGE 47

47 Figure 2-16. Cross-spectral analysis from a) Site 1207, b) Site 1208 c) Site 1209 d) Site 1210 ande) Site 1211. Power spectra for the tuned reflectance data (black) and for theastronomical solution for eccentricity and obliquity (red). Coherence values betweenthe astronomical solutions and reflectance data are shown below.

PAGE 48

48CHAPTER 3INTEGRATED NEOGENE MAGNETIC, CYCLE AND BIOSTRATIGRAPHY FROM ODPSITE 1208 (SHATSKY RISE, PACIFIC OCEAN)IntroductionODP Site 1208 was drilled in 2001 on Shatsky Rise, a large igneous province in the NWPacific Ocean. A single hole drilled at the site has produced a magnetic polarity stratigraphy forthe 0-12 Ma interval. Sedimentation rates decrease from 4-5 cm/kyr in the Brunhes andMatuyama chrons to less than 1 cm/kyr at the base of the studied section. A revised planktonicforaminifer biostratigraphic zonation has been developed for the NW Pacific Ocean using theseventeen most isochronous foraminifer datums. This scheme has been integrated withnannofossil events, and with the magnetic stratigraphy. Cycles in the reflectance (L*) can bematched to astronomic solution for obliquity allowing astronomic calibration of polarity chronboundaries, and planktonic foraminifer and calcareous nannofossil datums. Astronomic ages forpolarity chron boundaries are consistent with the ATNTS2004 timescale (Lourens et al., 2004) inthe 1-5.2 Ma interval, however, between 5.2 and 6.2 Ma, astronomic ages from Site 1208 differsignificantly (by ~ 300 kyr) from the ATNTS2004 timescale.As polarity reversals can be considered globally synchronous, the integration of polaritychron boundaries and biostratigraphies has become a powerful means of calibratingbiostratigraphic zonations, and determining synchroneity of biostratigraphic events (seeBerggren et al., 1995a,b). Early work on Neogene foraminifer biostratigraphy in the NorthPacific Ocean on Deep Sea Drilling Project (DSDP) Sites 173, 296 and 310 (Keller, 1979a,b,c)was augmented by foraminifer and nannofossil work on ODP Leg 138 in the eastern equatorialPacific (Raffi and Flores, 1995; Shackleton et al., 1995a). ODP Leg 138 biostratigraphies wereintegrated into well-defined magnetic stratigraphies (Schneider, 1995) and cyclostratigraphiesbased on gamma ray attenuation (GRA) bulk density data. Correlation of GRA bulk density

PAGE 49

49cycles to astronomical calculations for solar insolation provided robust age models for LateMiocene to Recent sediments (Shackleton et al., 1995b). The ODP Leg 138 age models wereamong the first astrochronologies developed for the Late Miocene to Quaternary, and hence thebiostratigraphies generated from ODP Leg 138 sites were rather precisely calibrated. Berggrenet al. (1995a,b) incorporated ages and bio-magnetostratigraphic data from ODP Leg 138 intotheir review of bio-magnetostratigraphic correlations for the Cenozoic and Quaternary.ODP Site 1208 offers the opportunity to refine biomagnetostratigraphic correlations for thelate Neogene. The attributes of ODP Site 1208 include: good preservation of foraminifers andcalcareous nannofossils, relatively high sedimentation rates compared to ODP Leg 138 sites, anda robust age model based on magnetic polarity stratigraphy and correlation of reflectance data toastronomical solutions.The study of ODP Site 1208 is a continuation of the work presented in Chapter 2, whichdeals largely with ODP Leg 198 sites other than Site 1208. An initial astrochronology for ODPSite 1208 (Chapter 2, Evans et al., 2005) was based on correlation of the shipboard reflectance(L*) data (Shipboard Scientific Party, 2002a) to the astronomical solution for obliquity of Laskaret al. (1993). Here, we update the Site 1208 astrochronology using the new astronomic solutionsof Laskar et al. (2004), present the Site 1208 magnetostratigraphy, foraminiferal and nannofossilbiostratigraphy, and link these stratigraphies to the new astrochronology. The recalibration ofthe Site 1208 age model makes little difference to the chronology presented in the previouschapter (and in Evans et al., 2005) because the astronomic solutions in the 0-12 Ma interval donot change significantly in Laskars two calculations (Laskar et al., 1993; 2004).Today, Shatsky Rise (Figure 3-1) lies in a subtropical water mass toward the north end of awarm-water mass known as the Kuroshio Extension Current (Shipboard Scientific Party, 2002b).

PAGE 50

50North of the Northern High of Shatsky Rise (Figure 3-1) lies a significant front, a transitionregion between subtropical and subarctic water masses. The transition zone waters are derivedfrom off the coast of northern Japan, where the cold, nutrient-rich Oyashio Current mixes withthe warm, nutrient-poor Kuroshio Extension Current. Middle Miocene calcareous planktonassemblages are rather uniform and diverse across Shatsky Rise and display warm, subtropicalaffinities. Since the Late Miocene, however, a faunal and floral gradient has been establishedacross Shatsky Rise (Shipboard Scientific Party, 2002b). Calcareous plankton assemblagesprogressively loose their warm-water taxa along a traverse from south to north across theShatsky Rise. At Sites 1207 and 1208 (Figure 3-1), there is a marked decrease in diversity inassemblages that assume temperate (occasionally cold-temperate) affinities, relative to sitesfurther south. The changes in calcareous plankton assemblages are paralleled by a progressivedecrease in calcareous preservation from north to south (Shipboard Scientific Party, 2002b).One of the most noticeable features of the upper Miocene through Pleistocene sectionsrecovered at Shatsky Rise is the decimeterto meter-scale cycles between darker and lighterlithologies. The darker-colored intervals, in general, contain larger amounts of well-preservedbiosiliceous material, and contain calcareous plankton assemblages that have cold-wateraffinities and have undergone relatively enhanced dissolution. Calcareous plankton preservationis enhanced in the light-colored layers that are poorer in diatoms and represent warmer-waterintervals when Site 1208 was located in a subtropical water mass, similar to the situation at Site1208 today and for the Southern High through most of the Neogene (Shipboard Scientific Party,2002b).

PAGE 51

51Site Location and LithologyODP Site 1208 is located in 3346m of water on the Central High of Shatsky Rise (Figure3-1). The Central High of the Rise had not been drilled prior to ODP Leg 198, and thesedimentary sequence at the site revealed ~260 m of Upper Miocene to Recent sediments with~60m of more condensed Lower and Middle Miocene below. A total of 314.17 m of Neogeneage sediment was recovered at the site with an average recovery of 95%. The Upper Miocene toRecent section is composed of nannofossil ooze and nannofossil clay with diatoms andradiolarians, and an average carbonate content of 53% (Shipboard Scientific Party, 2002b).Since 3 Ma, the average sedimentation rates were 4.2 cm/kyr. Prior to 3 Ma, sedimentation ratesdecrease progressively reaching 1 cm/kyr at ~8 Ma. The character of the seismic reflectionrecord at the site, along with the relatively high sedimentation rate that prevailed during thePliocene-Pleistocene, suggests that the stratified lens of sediment at the site constitutes a driftdeposit formed by current redistribution of sediment that settled on the Central High (ShipboardScientific Party, 2002b). The sediment drift deposits at Site 1208 are somewhat similar to thosedrilled along the Meiji Seamount during ODP Leg 145 in that both sections comprise fine-grained sediment devoid of sedimentary structures other than bioturbation (Rea et al., 1993).Magnetic StratigraphyMagnetic measurements on half cores from Site 1208, using the shipboard pass-throughmagnetometer, revealed an unambiguous magnetic stratigraphy, ranging in age from Recent toUpper Miocene (Figures 3-2, 3-3 and 3-4). The shipboard data are based on a singledemagnetization step (20 mT). This abbreviated treatment was necessary to preserve thesediment magnetization for later shore-based study, and to maintain core-flow through theshipboard core laboratory during the cruise. These shipboard data are supported using discretesample cubes (7cm3) collected from the working halves of cores, which were measured at the

PAGE 52

52University of Florida. The discrete sample cubes were AF demagnetized in 5mT increments upto peak fields of 80 mT. A steep drilling related overprint was removed by 20 mT peak field(Figure 3-5), and the primary magnetization was defined using the standard least squares method(Kirschvink, 1980), giving low maximum angular deviation (MAD) values indicating welldefined component magnetizations (Figures 3-2, 3-3 and 3-4).An initial age model and initial estimate of interval sedimentation rates were calculatedusing the magnetostratigraphy and the geomagnetic polarity timescale (GPTS) of Cande andKent (1995) (Figure 3-6a). Sedimentation rates decrease down section averaging 4-5 cm/kyr inthe Pleistocene, 3.5-4 cm/kyr in the Pliocene and 1-2 cm/kyr in the Miocene. The duration of theReunion subchron given in the Cande and Kent (1995) GPTS (10 kyr) causes a large increase inthe sedimentation rates in the polarity zone correlative to the Reunion subchron (Figure 3-2).Using a revised age and duration for the Runion subchron (Channell et al., 2003), sedimentationrates in the polarity zone correlative to the Reunion subchron are reduced to ~4 cm/kyr inkeeping with surrounding sedimentation rates.Numerous excursions can be identified in the shipboard magnetic stratigraphy particularlyin the Matuyama Chron, one of which (at 103 mbsf) is confirmed by a single discrete samplecorresponding to an age of 2.283 Ma. Channell et al., (2002) identified seven excursions in theMatuyama chron at ODP Site 983 in the North Atlantic that have been labeled: Santa Rosa (932ka), C1r.1n.1r (1048 ka), Punaruu (1115 ka), Bjorn (1255 ka), Gardar (1472-1480 ka), Gilsa(1567-1575 ka), and C2r.1r.1n (1977 ka).At ODP Site 1208, shallow inclinations are seen in shipboard data that appear to becorrelative to Santa Rosa (950 ka), Punaruu (1123 ka), Gardar (1450 ka), Gilsa (1522 ka), andC2r.1r.1n (1976 ka) (Figure 3-2). An interval of shallow inclination at 896 ka at Site 1208 may

PAGE 53

53correspond to the Kamikatsura excursion that originates from the work of Maenaka (1983).Three intervals of shallow inclination are also noted in the Brunhes chron with ages of 134, 193and 262 ka close to the published ages for the Blake excursion (120 ka), Iceland Basin excursion(189 ka) and 8! (260 ka) of Lund et al. (2001) (Figure 3-2). One potential excursion is noted inthe Gauss chron (Figure 3-3) and three potential excursions in the Gilbert chron (Figure 3-5).The ages for the Santa Rosa, Blake, Iceland Basin and 8! are calculated by assuming constantsedimentation rates within the Brunhes and subchron C1r.1r. Ages for other excursions are atSite 1208 are calculated from the astronomic age model described below. All the postulatedexcursions in the Site 1208 record should be regarded with some caution as they are based on asingle demagnetization step (20 mT peak field) from shipboard data.Cycle StratigraphyShipboard gamma ray attenuation bulk density data and L* reflectance data (ShipboardScientific Party, 2002), show a prominent cyclicity in the 1-6 Ma interval, that, based on theinitial age model has a period close to 41 kyr (see Chapter 2, Evans et al., 2005). Using theastronomical solutions of the Laskar et al. (2004), the L* reflectance data was tuned to obliquityby matching the L* output of a filter centered on 41 kyr to the orbital solution for obliquity(Figure 3-7). The resulting interval sedimentation rates for the 1-6 Ma interval are given inFigure 3-6b. The tuned ages for reversal boundaries, based on this match, are given in Table 3-2.The astronomical calibration of Site 1208 presented here is a recalibration of the astronomicaltimescale of Evans et al., (2005) using the updated astronomical solutions of Laskar et al. (2004).The recalibration to the new astronomic solutions resulted in little change to the astronomic agesfor Site 1208 relative to those given by Evans et al. (2005). Comparison of polarity reversal ageswith other timescales, and with results from IODP Site U1313 (Chapter 6), indicates close

PAGE 54

54agreement with differences < ~60 kyrs between 2.6 Ma and 5 Ma (Table 3-2). Beyond 5.2 Ma,the differences with respect to other timescales increase to over 100 kyr. In the 5.5-6 Ma interval,the polarity reversal ages from Site 1208 are closest to those of Shackleton et al. (1995b) fromODP Leg 138 (equatorial Pacific). The largest discrepancy beyond 5.2 Ma is with ATNTS2004timescale (Lourens et al., 2004) where the difference in ages is ~ 300 kyrs. The ATNTS2004timescale uses the work of Hilgen et al. (1995) from the Mediterranean in this interval.Calcareous NannofossilsCalcareous nannofossils were semi-quantitatively analyzed using smear slides andstandard light microscope techniques (Bown and Young, 1998). The following abundance andpreservation categories were used: Species abundance: abundant: >10 specimens per field ofview (FOV), common: 1 specimens per FOV, few: 1 specimen per 210 FOV, rare: 1specimen per 11 FOV. Total nannofossil abundance: abundant: >10%, common: 1%%,few: 0.1%%, rare: <0.1%, barren and questionable occurrence. Nannofossil preservation:good, moderate, poor (See range chart of Bown, 2005). All core catcher samples were examinedand ~60 other samples collected through the Late Miocene to Recent section. Biostratigraphy isdescribed with reference to the zonal scheme of Bukry (1973, 1975; zonal code numbers CN andCP added and modified by Okada and Bukry, 1980) for Cenozoic calcareous nannofossilbiostratigraphy.The middle MioceneHolocene section yielded a beautiful succession of rich and abundantnannofossil assemblages. Preservation improved up-section but was also dependent upon whichpart of the light/dark sedimentary cycle was sampled. The darker, diatom-rich intervals yieldedmore poorly preserved nannofossil assemblages (Shipboard Scientific Party, 2002). The Neogenenannofossil biostratigraphy indicates a relatively complete stratigraphy for the Pliocene-Pleistocene (Figure 3-8) and Miocene (Figure 3-9), with all nannofossil zones from CN5 through

PAGE 55

55CN15 identified by their primary zonal fossils (Figure 3-10). Calcareous nannofossil range chartsare shown in Bown (2005). Zones CN1CN5 could not be easily distinguished because of theabsence of the marker species Sphenolithus belemnos, Helicosphaera ampliaperta, andDiscoaster kugleri. In addition, a number of CN subzones could not be recognized due to theabsence of D. kugleri (Subzone CN5b), Discoaster loeblichii, Discoaster neorectus (SubzoneCN8b), and Amaurolithus amplificus (subdivisions within Zone CN9) and an anomalously lowlast occurrence (LO) of Triquetrorhabdulus rugosus (Subzone CN10b) (Bown, 2005).The astronomically calibrated ages of Pliocene to Quaternary calcareous nannofossildatums from Site 1208 (Table 3-3) are generally consistent with ages from Berggren et al.(1995b), that are based largely on work from the Mediterranean (Rio et al., 1990). The LO ofDiscoaster brouweri, however, differs significantly from Berggren et al. (1995b) in both age andcorrelative polarity chron (Table 3-3). The age of 1.95 Ma given by Berggren et al. (1995b),correlative to the onset of the Olduvai subchron, is based on correlation to Deep Sea DrillingProject (DSDP) Site 606 in the North Atlantic (Backman and Pestiaux, 1987).At Site 1208, the FO of Discoaster berggrenii in the Late Miocene is ~ 0.5 Myrs youngerthan the age reported in Berggren et al. (1995a). This age is based on correlation to polaritychron C4r.2r from ODP Leg 138. The age is more consistent with that seen at DSDP Site 608where the datum is correlated to polarity chron C4n (Ruddiman et al., 1987). The FO ofDiscoaster hamatus is a controversial datum (Berggren et al., 1995a) that has very inconsistentcorrelation to polarity chrons regardless of latitude. In ODP Leg 138 sites, it is correlative tosubchron C5n.2n, as at Site 1208. The FO of Catinaster coalitus is another controversial datumthat, at ODP Site 1208, is correlated to subchron C5n.2n similar to the correlation at ODP Leg138 sites. Berggren et al. (1995a) give an age of 10.8 Ma for the FO of Coccolithus

PAGE 56

56miopelagicus, 200 kyrs younger than the age from Site 1208 (Table 3-3), however the correlationof this datum to polarity subchron C5r.1r at Site 1208 is consistent with the correlation at DSDPSite 608.Planktonic Foraminifera158 samples were analyzed for planktonic foraminifers at ~1.5 m intervals, together withcore-catcher samples (from the base of each core) collected shipboard from the 320-m-thickupper Neogene section at ODP Site 1208. The samples were soaked in a slightly basic solution,shaken, washed over a 63 !m sieve and dried at 60C. Specimens of planktic and benthicforaminifers were picked from the >125 !m fraction. Specimens of all recognizable plankticspecies were identified following the classic taxonomies of Kennett and Srinivasan (1983), Bolliand Saunders (1985), Jenkins (1985), and Iaccarino (1985). Shipboard and shore-basedoccurrence tables were combined to determine a planktic foraminifer biostratigraphy.Occurrence estimates were based on the following percentages: Rare=1%, rare to few=3%,few=5%, few to common=8%, common=10%, common to abundant=15%, abundant =>20%,Planktonic foraminiferal abundance varies from abundant to common through thePleistocene and upper Pliocene but declines in the Miocene to few to rare relative to siliceousmicrofossils and clay. Temperate-water species dominate many of the Neogene planktonicforaminiferal assemblages at Site 1208 (Shipboard Scientific Party, 2002b).The magnetostratigraphically-interpolated ages for many foraminiferal datums on ShatskyRise differed significantly from those reported from the southwest Pacific, due to regionalmigration patterns. Application of zonal schemes proposed for the southwest Pacific (Jenkins,1985) and the mid-latitudes were complicated by unexpected changes in the sequence offoraminiferal datums observed at Shatsky Rise. A revised temperate foraminifer biostratigraphy

PAGE 57

57for the late Neogene uses seventeen of the most isochronous foraminiferal datums at ShatskyRise as zonal markers (shown in Figure 3-11).Discrepancies between published ages for planktonic foraminifer datums (Berggren et al.,1995a,b; Lourens et al., 2004) and those identified at Site 1208 are large in some cases. (Tables3-4 and 3-5). The majority of the magneto-biostratigraphic correlations used in Berggren et al.,(1995a,b) and Lourens et al. (2004) are from the Mediterranean (Hilgen, 1990), South Atlantic(Hodell and Kennett, 1987) or South Pacific (Srinivasan and Sinha, 1993). The comparison ofthe ages of the planktic foraminifer datums is affected by regional differences and varying zonalschemes (Tables 3-4 and 3-5).The LO of Gr. tosaensis at ODP Site 1208 is at 0.292 Ma, significantly younger than theage of 0.65 Ma given by Berggren (1995b). This datum is taken from the work of Berggren et al.(1985) and Srinivasan and Sinha (1993) from the southern Pacific and Indian Oceans. The LOdatum of Gr. punticulata has an age of 1.882 Ma at Site 1208, however, an age of 2.41 Ma wasobtained at DSDP Site 607 (North Atlantic) where it is correlative to polarity subchron C2An.2n.The FO of Gr. truncatlinoides occurs at the same stratigraphic level as the FO of Gr.toseanis at ODP Site 1208. Following Berggren et al. (1995b), the FO of Gr. toseanis has an ageof 3.35 Ma. At Site 1208, the astronomically calibrated age of the event is 2.015 Ma. The Site1208 age for this datum is more consistent with the astronomically calibrated age for the FO ofGr. truncatlinoides of 2.39 Ma from ODP Leg 138 in the eastern equatorial Pacific (Shackletonet al., 1995a). The LO of Gr. margaritae was assigned an age of 3.85 Ma in the ATNTS2004(Lourens et al., 2004) from ODP Sites 925 and 926 from Ceara Rise. The astronomic age for thedatum at Site 1208 is 3.761 Ma.

PAGE 58

58ConclusionsODP Site 1208 has produced a clear magnetic stratigraphy for the 0-12 Ma interval withsedimentation rates in the Brunhes and Matuyama chrons varying in the 4-5 cm/kyr range. Thesesedimentation rates are some of the highest sedimentation rates seen in this interval in pelagicsediments from the midand low latitude Pacific Ocean. This anomalously high sedimentationrate appears to be due to formation of a drift-type deposit on the Central High of Shatsky Rise.The relatively high sedimentation rates have allowed identification of polarity excursions in theMatuyama Chron that have not been previously identified in sediments from the Pacific Ocean.It is important to stress that these excursions are identified in shipboard pass-through magneticdata, and are not based on identification of magnetization components. For this reason, theratification of these excursional directions must await further (u-channel) studies of thesesediments.Reflectance (L*) cycles identified in the sediments have allowed astronomic calibration ofreversal boundaries and biostratigraphic datums, by correlation of L* reflectance data to theastronomic solution for obliquity (Laskar et al., 2004). Calcareous nannofossil biostratigraphy islargely consistent with the most recent review of bio-magnetostratigraphic correlations for thistime interval (Berggren et al., 1995a, b). Based on the correlation of planktonic foraminiferdatums to the magnetic stratigraphy at Site 1208, a new planktonic foraminifer zonation for thenorthwest Pacific Ocean has been developed that can be precisely correlated to polarity chronsand astronomically calibrated ages.

PAGE 59

59Table 3-1. Depths of reversal boundaries from ODP Site 1208. Chrons are labeled according toCande and Kent (1992). Ages for polarity chrons are from Cande and Kent (1995)and Channell et al., (2003). Chron Ma (CK95) mbsf Chron Ma (CK95) mbsf C1n 0 0 C3Br.1n 6.946 base 0.78 42.92 base 6.981 C1r.1n 0.99 52.57 C3Br.2n 7.153 base 1.07 55.85 base 7.187 240.33 C1r.2r.1n 1.201 61.18 C4n.1n 7.245 241.08 base 1.211 61.67 base 7.376 241.83 C2n 1.77 85.01 C4n.2n 7.464 242.95 base 1.95 92.81 base 7.892 250.78 C2r.1n* 2.115 99.86 C4r.1n 8.047 251.71 base* 2.153 101.01 base 8.079 252.46 C2An.1n 2.581 119.45 C4An 8.529 256 base 3.04 137.8 base 8.861 260.66 C2An.2n 3.11 140.64 C4Ar.1n 9.069 262.53 base 3.22 144.58 base 9.146 264.02 C2An.3n 3.33 147.76 C4Ar.2n 9.428 265.69 base 3.58 156.88 base 9.491 268.12 C3n.1n 4.18 172.4 C5n.1n 9.592 269.05 base 4.29 176.47 base 9.735 271.85 C3n.2n 4.48 182.51 C5n.2n 9.777 base 4.62 185.46 base 10.834 282.1 C3n.3n 4.8 189.28 C5r.1n 10.94 287.14 base 4.89 191.01 base 10.989 287.69 C3n.4n 4.98 194.09 C5r.2n 11.378 290.49 base 5.23 200.04 base 11.434 291.42 C3An.1n 5.894 216.47 C5An.1n 11.852 292.17 base 6.137 221.51 base 12 294.03 C3An.2n 6.269 222.25 C5An.2n 12.108 298.69 base 6.567 231.39 base 12.333 299.63 C3Bn 6.935 235.31 base 7.091 240.34 age from Channell et al. (2003)

PAGE 60

60Table 3-2. Astronomically calibrated ages for reversal boundaries from ODP Site 1208 comparedto ATNTS2004 (Lourens et al., 2004), Cande and Kent (1995), IODP Site U1313(Evans et al., in preparation, Chapter 6), Hilgen et al., (1995) and ODP Leg 138(Shackleton et al., 1995b). Differences between Site 1208 ages and published ages aregiven in parentheses. Chron 1208tuned age(Ma) CK95 (Ma) Hilgen et al.(1995) (Ma) ATNTS2004 (Ma) ODP Leg 138 IODP SiteU1313Chapter 6 C1n base 0.780 C1r.1n 0.990 base 1.062 1.070 (-0.008) 1.072 (0.01) C1r.2r.1n 1.158 1.201 (0.043) 1.173 (0.015) base 1.167 1.211 (0.044) 1.185 (0.018) C2n 1.763 1.770 (-0.007) 1.785 (0.022) 1.778 (0.015) base 1.944 1.950 (-0.006) 1.942 (-0.002) 1.945 (0.001) C2r.1n 2.204 2.140 (0.064) 2.129 (-0.075) 2.128 (-0.076) base 2.214 2.150 (0.064) 2.149 (-0.065) 2.148 (-0.066) C2An.1n 2.616 2.581 (0.035) 2.582 (-0.34) 2.581 (-0.035) 2.600 (-0.016) 2.616 (0) base 3.048 3.040 (0.008) 3.032 (0.016) 3.032 (-0.016) 3.046 (-0.002) 3.074 (0.026) C2An.2n 3.091 3.110 (-0.019) 3.116 (0.025) 3.116 (0.025) 3.131 (0.04) 3.153 (0.062) base 3.207 3.220 (-0.013) 3.207 (0) 3.207 (0) 3.233 (0.026) 3.268 (0.061) C2An.3n 3.350 3.330 (0.020) 3.330 (-0.02) 3.330 (-0.02) 3.331 (-0.019) 3.346 (-0.004) base 3.584 3.580 (0.004) 3.569 (-0.015) 3.596 (0.012) 3.594 (0.01) 3.549 (-0.035) C3n.1n 4.164 4.180 (-0.016) 4.188 (0.024) 4.187 (0.023) 4.199 (0.035) 4.144 (-0.02) base 4.307 4.290 (0.017) 4.300 (-0.010) 4.300 (-0.007) 4.316 (0.009) 4.277 (-0.03) C3n.2n 4.484 4.480 (0.004) 4.493 (+0.009) 4.493 (0.009) 4.479 (-0.005) 4.500 (0.016) base 4.601 4.620 (-0.019) 4.632 (0.031) 4.631 (0.03) 4.623 (0.022) 4.631 (0.03) C3n.3n 4.785 4.800 (-0.015) 4.799 (0.014) 4.799 (0.051) 4.781 (-0.004) 4.760 (-0.025) base 4.897 4.890 (0.007) 4.879 (-0.018) 4.896 (-0.001) 4.878 (-0.019) 4.889 (-0.008) C3n.4n 4.987 4.980 (0.007) 4.998 (0.011) 4.997 (0.01) 4.977 (-0.01) 5.009 (0.022) base 5.182 5.230 (-0.048) 5.236 (0.054) 5.235 (0.053) 5.232 (0.05) 5.273 (0.091) C3An.1n 5.735 5.894 (0.159) 5.952 (0.217) 6.033 (0.298) 5.875 (0.14) base 5.955 6.137 (0.182) 6.214 (0.259) 6.252 (0.297) 6.122 (0.167)

PAGE 61

61Table 3-3. Nannofossil datums for ODP Site 1208 (Bown, 2005). Ages for the datums areinterpolated from the magnetic stratigraphy (this work) and the correlative polaritychron is given. The datums are compared to ages given by Berggren et al. (1995a, b).Tuned ages for the datums are compared to ATNTS2004 (Lourens et al., 2004) andODP Leg 138 ages for nannofossil datums only (Raffi and Flores, 1995; Shackletonet al., 1995a). Datum Depth(mbsf) 1208Mag. strat.Age (Ma) ChronSite 1208 Berggren etal.1995a b(Ma) chron ODPLeg138 1208Tunedage (Ma) ATNTSage(Ma) FO Emiliania huxleyi 14.24 0.258 C1n 0.26 0.26 0.29 LO P. lacunosa 30.30 0.551 C1n 0.46 0.46 0.44 FO G. omega 43.11 0.784 C1r.1r FO G. caribbeanica 87.90 1.837 C2n 1.841 LO D. brouweri 100.16 2.143 C2r.1n 1.95 Olduvai 1.96 2.146 2.06 LO D. pentaradiatus 116.40 2.510 C2r.2r 2.46-2.56 M/Gboundary 2.52 2.499 2.39 LO D. surculus 119.08 2.572 C2r.2r 2.55-2.59 M/Gboundary 2.63 2.556 2.52 LO D. tamalis 128.70 2.812 C2An.1n 2.78 top Gauss 2.78 2.802 2.80 LO LargeReticulofenestra 163.90 3.851 C2Ar 3.833 FO D. tamalis 166.66 3.65 C2Ar 3.95 LO Sphenolithus 166.66 3.65 C2Ar 3.6 base Gauss 3.66 3.95 LO Amaurolithus 168.88 4.56 C2Ar 4.03 FO D. asymmetricus 168.88 4.56 C2Ar 4.2 top Cochiti 4.13 4.03 FO C. cristatus 187.90 4.735 C3n.2r 4.750 LO D. quinqueramus 207.00 5.551 C3r 5.6 C3r 5.55 5.472 5.59 FO Amaurolithus 235.52 6.941 C3Bn FO D. quinqueramus 250.80 8.075 C4r.1r FO D. berggrenii 250.80 8.075 C4r.1r 8.6 C4r.2r 8.45 FO D. hamatus 265.94 9.586 C4Ar.2n 9.4 C4Ar.2r FO C. calyculus 270.10 9.792 C5n.1n 10.79 FO D. hamatus 274.20 10.125 C5n.2n 10.7 10.38 10.55 FO C. coalitus 279.70 10.699 C5n.2n 10.9 10.89 LO C. miopelagicus 285.06 11.009 C5r.1r 10.8 11.02 LO C. premacintyrei 295.41 13.19 C5An.1r 12.65 11.21 LO C. floridanus 295.41 13.19 C5An.1r 13.19 13.33

PAGE 62

62Table 3-4. Plio-Pleistocene foraminfer datums, with depths, correlative polarity chron, tuned ageand compared to Berggren et al. (1995a, b) and ATNTS 2004 (Lourens et al., 2004)from ODP Legs 138 and 111. Event Depthmbsf 1208mag stratage ChronSite 1208 Berggren etal 95ab age(Ma) 1208tunedage ATNTSAge LO Gr. crassula 0.4 0.007 C1n LO Gr. tosaensis 16.1 0.292 C1n 0.65 C1n 0.61 LO Gs. bulloideus 38.2 0.694 C1n LO B. praedigitata 43.7 0.797 C1r.1r LO Gt. woodi 53.2 1.005 C1r.1n 1.004 2.3 LO Gs. bollii 60.5 1.182 C1r.2r 1.197 LO Gs. obliquus 66.7 1.331 C1r.2r 1.34 1.3 LO N. acostaensis 76.2 1.559 C1r.2r 1.562 1.58 LO N. humerosa 79.6 1.640 C1r.2r 1.653 LO Gt. decoraperta 83.6 1.736 C1r.2r 1.742 2.75 LO Gr. puncticulata, FO Gs. tenellus,FO Gs. elongatus 89.7 1.878 C2n 2.41 1.882 2.41 FO Gr. hirsuta 92.3 1.938 C2n 1.930 FO Gr. toseansis, LO Gr. cibaoensis, FO Gr.truncatulinoides 95.2 2.014 C2r.1r 3.35C2An.2n 2.015 1.93 LO Pu. primalis, LO Gr. limbata FO Ga. parkerae 98.5 2.103 C2r.1r 2.116 FO Pu. obliquiloculata, FO B. digitata 101.9 2.171 C2r.2r 2.164 LO Gq. venezuelana 108.1 2.316 C2r.2r 2.282 LO Ss. paenedehiscens, LO Gt. apertura 111.4 2.393 C2r.2r 2.382 LO N. dupac, FO Ge. siphonifera 121.5 2.632 C2An.1n 2.621 LO Gr. pseudomiocenica 123.0 2.670 C2An.1n 2.654 LO Gr. juanai, FO Gr. bermudezi 125.8 2.740 C2An.1n 2.714 LO Gr. plesiotumida, LO Gs. extremus,LO Gs. triloba 132.5 2.907 C2An.1n 2.902 FO Gr. limbata 135.3 2.978 C2An.1n 2.966 LO Gq. conglomerata, LO Gr. sphericomiozea 137.2 3.250 C2An.1n 3.024 FO Pu. primalis 142.2 3.154 C2An.2n 3.147 LO Gr. inflata 146.2 3.276 C2An.2r 3.301 FO Gt. rubescens 147.4 3.318 C2An.2r 3.338 FO Gr. puncticulata, LO Gr. conoidea 150.0 3.391 C2An.3n 4.5 Nunivak 3.427 FO Sa. dehiscens 151.5 3.433 C2An.3n 5.2 E.Gilbert 3.457 LO Ge. pseudobesa 158.2 3.631 C2Ar 3.637 FO Ge. calida, FO Gr. crassula, LO D. altispira, LO Ss.seminulina 159.6 3.740 C2Ar 3.682 LO Ss. kochi 161.0 3.739 C2Ar 3.708 4.53 LO Gr. margaritae 162.4 3.793 C2Ar 3.58 G/Gboundary 3.761 3.85 FO Gs. bulloideus 165.0 3.894 C2Ar 3.871 FO Gq. conglomerata, FO Gr. crassiformis 172.0 4.165 C2Ar 4.187 FO Ga. uvula, FO Gs. extremus,LO Gr. conomiozea 178.7 4.360 C3n.1r 4.413 FO Gg. umbilicata, FO Ge. aequilateralis 182.9 4.499 C3n.2n 4.54 FO Gr. sphericomiozea 186.5 4.669 C3n.2r 5.6 C3r 4.696 FO Gr. conomiozea, LO Gt. nepenthes,FO Gr. pseudomiocenica 190.8 4.879 C3n.3n 4.2 Cochiti 4.873 4.37

PAGE 63

63Table 3-5. Miocene foraminifer datums, with depths, correlative polarity chron, tuned age andcompared to Berggren et al. (1995a, b) and ATNTS 2004 (Lourens et al., 2004) fromODP Legs 138 and 111. Datum Depth(mbsf) 1208 magstrat age(Ma) ChronSite 1208 Berggrenet al.(1995b) 1208tunedage ATNTS2004 FO Gr. tumida, LO Gs. kennetti 203.1 5.354 C3r 5.6 C3r 5.327 5.57 FO Gs. bollii 209.4 5.608 C3r 5.591 FO Gs. kennetti 211.3 5.685 C3r 5.675 FO Gd. hexagona 214.3 5.806 C3r 5.816 FO N. dutertrei, FO Gs. conglobatus 217.3 5.934 C3An.1n 5.961 6.2 FO Ss. paenedehiscens, LO Gr.merotumida 224.5 6.342 C3An.2n FO Ge. pseudobesa, FO Gr. margaritae,FO Ss. kochi, FO Gr. plesiotumida, FO N. humerosa, FO Gr. scitula 227.3 6.434 C3An.2n 6.0 C3An LO Gr. miotumida c.f. 233.6 7.0 C3Ar FO Gr. cibaoensis, FO N. acostaensis,FO Gr. miotumida c.f. 240.2 7.4 C3Bn 7.8 C4n.2n LO Gq. baroemoenensis 245.9 7.9 C4n.2n FO Gr. juanai 251.1 8.1 C4r.1r FO B. praedigitata, FO Gs. obliquus,FO N. pachyderma (dextral), (sinistral) 255.6 8.7 C4r.1r FO Gs. ruber, FO Gt. apertura, LO Gq.dehiscens 263.1 9.4 C4Ar.1n FO Gr. merotumida 270.5 9.9 C5n.1n LO Gr. praemenardii 272.6 10.0 C5n.2n FO N. dupac 276.8 10.2 C5n.2n LO Gt. druryi 282.3 11.0 C5r.1r LO Ss. disjuncta 284.3 11.1 C5r.1r 11.49 FO Gt. decoraperta 285.0 11.1 C5r.1r FO Gr. miozea 291.9 11.8 C5r.3r LO Gr. mayeri 294.1 12.1 C5An.1r LO N. continuosa 295.2 12.1 C5An.1r LO Cs. parvulus, LO Gr. panda 296.8 12.2 C5An.1r 11.8C5r.3r FO Gt. nepenthes, FO Gr. mayeri, FO Gr.menardii 298.9 12.3 C5An.2n 11.8C5r.3r 11.63 FO Gt. druryi 299.7 12.3

PAGE 64

64 Figure 3-1. Bathymetric map showing the location of Shatsky Rise in the Pacific Ocean and alarger map of Shatsky Rise showing the Sites drilled on ODP Leg 198 including Site1208 on the Central High of the Rise (after Bown, 2005).

PAGE 65

65 Figure 3-2. Inclination, declination and MAD values plotted against meters below sea floor. Grayline indicates the AF demagnetization data from the shipboard pass-throughmagnetometer at the 20 mT demagnetization step. Open squares indicate data fromdiscrete samples. The polarity interpretation is shown in black (normal polarity) andwhite (reverse polarity) and chrons are labeled according to Cande and Kent (1992,1995). Excursions are labeled according to Channell et al. (2002) and Singer et al.(1999). Ages for excursions are calculated from the astronomic age model for Site1208.

PAGE 66

66 Figure 3-3. Inclination, declination and MAD values plotted against meters below sea floor. Grayline indicates data from the shipboard pass-through magnetometer at the 20 mTdemagnetization step. Open squares indicate data from discrete samples. The polarityinterpretation is shown in black (normal polarity) and white (reverse polarity) andchrons are labeled according to Cande and Kent (1992, 1995). Excursions are labeledaccording to Channell et al. (2002) and Singer et al. (1999). Ages for excursions arecalculated from the astronomic age model for Site 1208.

PAGE 67

67 Figure 3-4. Inclination, declination and MAD values plotted against meters below sea floor. Grayline indicates data from the shipboard pass-through magnetometer. Open squaresindicate data from discrete samples. The polarity interpretation is shown in black(normal polarity) and white (reverse polarity) and chrons are labeled according toCande and Kent (1992, 1995). Gray bar indicates indeterminate polarity.

PAGE 68

68 Figure 3-5. Orthogonal projections showing AF demagnetization data from discrete samples.Open circles represent the vector end point projections on the vertical plane andclosed circles represent vector end point projections on the horizontal plane.

PAGE 69

69 Figure 3-6. a) Interval sedimentation rates (black line) and age versus depth (red line) calculatedfrom the magnetostratigraphic data. b) interval sedimentation rates calculated for thetuned age model for the 1-6 Ma interval.

PAGE 70

70 Figure 3-7. Reflectance (L*) data (black line) tuned to the astronomic solution for obliquity fromLaskar et al. (2004). Lower plots shows the output of a gaussian filter centered on theobliquity frequency (0.024), applied to the reflectance (L*) data.

PAGE 71

71 Figure 3-8. Plio-Pleistocene planktonic foraminifer and calcareous nannofossil datums, corerecovery, and magnetostratigraphy, plotted against meters below the sea floor. Agesin bold are astronomically calibrated ages from this study. Ticks indicate position ofsamples taken for foraminifer analysis. Depths in mbsf of datums are given inparentheses before the datum.

PAGE 72

72 Figure 3-9. Miocene planktonic foraminifer and calcareous nannofossil datums core recovery,and magnetostratigraphy, plotted against meters below the sea floor (after Venti,2006). Ages in bold are astronomically calibrated ages from this study. Ticks indicateposition of samples taken for foraminifer analysis. Depths in mbsf of datums aregiven in parentheses before the datum.

PAGE 73

73 Figure 3-10. Calcareous nannofossil biostratigraphy including the zonations of Martini (1971)and Okada and Bukry (1980) modified from Bukry (1973, 1975). Ages in bold areastronomically calibrated ages from this study.

PAGE 74

74 Figure 3-11. A proposed biostratigraphy for the mid-latitude North Pacific uses 16 plankticforaminifer datums to divide the late Neogene into 15 biozones. The new stratigraphyis integrated into the Geomagnetic Polarity Timescale and compared to pre-existingplanktic foraminifer zonal schemes for temperate and tropical region, as well as totropical calcareous nannofossil zonations (after Venti, 2006). Abbreviations forzonations are as follows: B69: Blow (1969) modified by Kennett and Srinivasan(1981a, 1981b) BKSA95: Berggren et al. (1995b) J85: Jenkins (1985) SK81:Srinivasan and Kennett (1981a) M71: Martini (1971) B73,75: Bukry (1973, 1975),OB80 Okada and Bukry, (1980): Ages in bold are astronomically calibrated agesfrom this study.

PAGE 75

75CHAPTER 4PALEOINTENSITY-ASSISTED CHRONOSTRATIGRAPHY OF DETRITAL LAYERS ONTHE EIRIK DRIFT (NORTH ATLANTIC) SINCE MARINE ISOTOPE STAGE 11IntroductionThe Eirik Drift drapes the top of the underlying Eirik Ridge located off the southern tip ofGreenland (McCave and Tucholke, 1986). Magnetic anomalies have not been identified directlybeneath the Eirik Ridge, although the adjacent oceanic crust in both the Irminger Basin andLabrador Sea is associated with marine magnetic anomaly 24 of Paleocene-Eocene boundary age(Srivastava and Tapscott, 1986). The Eirik drift is 800 km long and has been constructed by theinteraction of the southwestward flowing Western Boundary Undercurrent (WBUC) andbasement topography (Chough and Hesse, 1985). The WBUC carries water masses originatingfrom the Norwegian and Greenland Seas that enter the North Atlantic over the Iceland-ScotlandRidge and Denmark Strait (McCave and Tucholke, 1986; Lucotte and Hillaire-Marcel, 1994).The WBUC moves over, and constructs the Eirik Drift and then follows bathymetric contoursaround the Labrador Basin (McCave and Tucholke, 1986).Drilling on the Eirik Drift includes Site 646 (ODP Leg 105), and piston and gravity corescollected during cruises by the CSS Hudson in 1990, the Marion Dufresne in 1999 and the R/VKnorr in 2002. Seismic records used to extrapolate the sequence recovered at Site 646 indicatethat the drift has been constructed since the middle to early Pliocene (Arthur et al., 1989).Although sedimentation on the drift sequence was more or less continuous during the LatePliocene and Pleistocene, sedimentation rates vary considerably with glacial/interglacialconditions and with location on the drift.Piston cores HU90-013-012 (water depth: 2830 m) and HU90-013-013 (water depth: 3380m) (Figure 4-1, Table 4-1), collected in 1990 during a cruise of the CSS Hudson, record the lastglacial cycle at differing water depths on the Eirik Drift (Hillaire-Marcel et al., 1994). Core

PAGE 76

76HU90-013-013 shows high sedimentation rates in the Holocene while Core HU90-013-012 hasvery low Holocene sedimentation rates due to winnowing by the WBUC (Stoner et al., 1995a,1996). Increases in magnetic concentration and grain size during the early Holocene and at theMIS 6/5e transition in HU90-013-013, were attributed to detrital influx associated with retreat ofthe Greenland Ice sheet (Stoner et al., 1995b). In core HU90-013-013, four discrete detritallayers were identified within MIS 2 and 3 based on their magnetic properties (coarse magneticgrain size) and relatively high percent carbonate values. Stoner et al. (1996) correlated three ofthese detrital layers with Heinrich events 1, 2 and 4. Stoner et al., (1998) revised the chronologyfor core HU90-013-013 by correlation to SPECMAP (Martinson et al., 1987) and refined theages and correlation of the detrital layers to North Atlantic detrital layers.We present data from three jumbo piston cores (JPC15, JPC18, JPC19) collected on theEirik Drift in the summer of 2002 during Cruise KN166-14 of the RV Knorr, and from CoreMD99-2227 collected during the 1999 Images campaign (Figure 4-1). JPC15 was taken on theupper slope of the ridge at a water depth of 2230 m. Core JPC19 was collected from the crest ofthe ridge at a water depth of 3184 m, and Core JPC18 from the southern flank of the ridge at awater depth of 3435 m. Core MD99-2227 was collected from the western toe of the drift at 3460m water depth. The recovered sediments are mostly dark gray bioturbated silty clays, with clayeysilt and sandy mud, and occasional gray nannofossil/foraminifer rich clayey silt layers (seeTuron, Hillaire-Marcel et al., 1999, for a lithologic description of MD99-2227).MethodsU-channel samples (2x2 cm square cross-section and 150 cm in length) were collectedfrom the center of the split face of piston core sections. These samples were measured on a 2G-Enterprises pass-through cryogenic magnetometer at the University of Florida. Natural remanentmagnetization (NRM) was demagnetized step-wise using alternating fields (AF) in 5 mT

PAGE 77

77increments for 0-60 mT peak fields, and in 10 mT increments for 60 mT-100 mT peak fields.Volume susceptibility was then measured using a susceptibility track specifically designed for u-channels (Thomas et al., 2003) that has a measurement resolution of a few centimeters.Anhysteretic remanent magnetization (ARM) was applied using an AF field of 100 mT and abias DC field of 50 !T. Isothermal remanent magnetization (IRM) was imparted using a 0.5 TDC field. Both artificial remanences were demagnetized with the same AF steps used todemagnetize NRM. Principal components were calculated from the NRM data using the methodof Kirschvink (1980) applied to the 20-80 mT interval. Relative paleointensity proxies weregenerated by normalizing the NRM data by both ARM or IRM, demagnetized at a common peakfield. A mean of nine normalized remanence values, in the 20-60 mT peak field range, was usedto generate the relative paleointensity proxies. ARM and susceptibility data were also used toascertain magnetic grain size changes that help define detrital layers. The parameter karm(anhysteretic susceptibility), obtained by normalizing ARM intensity by the strength of the dcfield used to acquire the ARM, was divided by volume susceptibility, to determine karm/k, aproxy for magnetite grain size.On completion of the magnetic measurements on the u-channel samples, X-radiographswere taken across detrital layers, identified by u-channel magnetic measurements and carbonateanalyses, to provide a picture of the internal structure of these layers and identify the presence orabsence of traction structures. Discrete toothpick-sized samples, collected at 1-cm intervalsacross detrital layers, were used for smear slide observation (Table 4-2) and for measurement ofmagnetic hysteresis parameters using a Princeton Measurements Corp. vibrating samplemagnetometer (VSM). Magnetic hysteresis parameters provide a means of estimating magnetitegrain size, and therefore of recognizing grading in detrital layers.

PAGE 78

78Cores were sub-sampled for oxygen isotope analysis at 5-cm spacing. Samples from CoreMD99-2227 were analyzed at GEOTOP (Montreal) while samples from the KN166-14 coreswere analyzed in the stable isotope laboratory at Rutgers University. For all the cores,foraminifer shells of the planktonic species Neogloboquadrina pachyderma (left coiling) werepicked in the 150-250 m fraction for the isotopic analyses. Planktonic foraminifer species wereused for the isotopic analyses due to the small amount of benthos present in the cores. For CoreMD99-2227, samples were collected at 5 cm intervals for carbonate analyses using an elementalanalyzer.Age models for the piston cores were constructed by matching relative geomagneticpaleointensity records and planktic "18O records to target curves, with the location of magneticexcursions (Laschamp and Iceland Basin) providing additional age constraints. The combinationof paleointensity records and oxygen isotope data provide enhanced temporal resolutioncompared to using either dataset independently.NRM and Normalized Remanence RecordThe natural remanent magnetization (NRM) data for all four cores are shown ascomponent inclination, corrected component declination, and maximum angular deviation(MAD) values (Figure 4-2). Cores were not oriented during collection, and therefore declinationdata were corrected by aligning the mean declination of each core to North. Twisting withincores during the coring process is indicated by anomalous declination changes in Core JPC18(114.5-189 cm) (Figure 4-2). Core MD99-2227 is affected by stretching in the upper 7 metersthat has significantly affected the magnetization directions (Figure 4-2).

PAGE 79

79Polarity ExcursionsBrief polarity excursions are a characteristic of the geomagnetic field, at least during thelast ~2 Myr, and excursions of known age provide useful stratigraphic markers. Componentmagnetizations from u-channels indicate directional excursions at 9.3 meters below seafloor(mbsf) in Core JPC15, at 13.4 mbsf in Core JPC18, and at 18.7 mbsf in Core JPC19 (Figures 4-2and 4-3). For Core JPC15, the observed excursion is correlated to the Laschamp excursion (~41ka). For Cores JPC18 and JPC19, the observed excursion is correlated to the Iceland Basinexcursion (~185 ka). Orthogonal projections of alternating field demagnetization data fromintervals recording the Iceland Basin excursion in Cores JPC18 and JPC19 (Figure 4-3) indicatethat the excursions are unambiguously recorded by u-channel samples and by discrete samplescollected alongside the u-channel trough.Relative PaleointensityIt is generally accepted that the generation of useful paleointensity proxies requires that thesediments contain magnetite as the only NRM carrier. Also the sediment should have a narrowrange of magnetite concentration, as indicated by magnetic concentration parameters varying byless than an order of magnitude, and have restricted magnetite grain-size in the few micron grain-size range, corresponding to pseudo-single domain grains (Tauxe, 1993). There is no evidencefrom demagnetization characteristics of NRM, or from hysteresis parameters, for high-coercivitymagnetic minerals such as hematite or pyrrhotite. Using plots of anhysteretic susceptibilityagainst susceptibility, and the calibration of King et al. (1983), we estimate that these sedimentsgenerally have magnetite grain sizes in the 1-10 m range (Figure 4-4). Records of ARM, IRMand susceptibility (Figure 4-5) show that the concentration parameters generally vary within anorder of magnitude, the limit deemed suitable for determination of relative paleointensity proxies

PAGE 80

80(Tauxe, 1993). The exception is within the coarser-grained intervals in the early part ofinterglacials, where the concentration parameters vary by more than an order of magnitude.NRM measured on u-channel samples was normalized using both ARM and IRM,demagnetized at the same peak fields as the NRM. To generate the paleointensity proxies, amean of nine demagnetization steps in the 20-60 mT interval were used to calculate meanNRM/ARM and mean NRM/IRM. Although the two proxies are generally consistent with eachother, mean NRM/ARM has the lower standard deviations and was therefore chosen as thepreferred paleointensity proxy.ChronologyTo construct age models for the four cores in this study, we correlate the planktonicoxygen isotope records to the benthic oxygen isotope stack (Lisiecki and Raymo, 2004). We thenadjust this correlation to optimize the fit of the relative paleointensity records to thepaleointensity record from ODP Site 983 (Channell et al., 1997; Channell, 1999). FollowingStoner et al. (2003), the paleointensity and oxygen isotope data from ODP Site 1089 were usedto improve the age model for ODP Site 983 particularly in the MIS 3-4 interval. For the EirikDrift cores, a combination of oxygen isotope data and relative paleointensity data can produce ahigher-resolution age model than would be possible using either data set independently.The magnetic excursion recorded at 18.7 mbsf in JPC19 (Figures 4-2 and 4-3) isinterpreted as the Iceland Basin excursion (Channell et al., 1997; Channell, 1999). It lies in aprominent paleointensity low at 185 ka in JPC19 (Figure 4-6), consistent with the expected ageof this excursion. According to the age model, Core JPC19, from the crest of the drift at a waterdepth of 3184 m, has an age at its base of 300 kyrs with a mean sedimentation rate of 10.5cm/kyr.

PAGE 81

81In Core JPC18, from southern flank of the Eirik ridge at a water depth of 3435 m,sediments coeval with interglacial periods are apparently missing, as shown by the lack ofHolocene oxygen isotope values (Figure 4-7). MIS 5e is also absent in the record, becauseoxygen isotope values in this interval are too high for full interglacial values. The polarityexcursion observed at 13.45 mbsf (Figures 4-2 and 4-3) is identified as the Iceland Basinexcursion and it occupies a distinct paleointensity low at 185 ka (Figure 4-7), an age consistentwith the observation of this excursion elsewhere. The overall mean sedimentation rate in CoreJPC18 is 9 cm/kyr.Core JPC15 was taken on the upper slope of Eirik ridge at a water depth of 2230 m. Thepolarity excursion observed at 9.3 mbsf in Core JPC15 (Figures 4-2 and 4-3) occurs within aprominent paleointensity low at ~ 40 ka (Figure 4-8) and is therefore interpreted as theLaschamp excursion. The base of JPC15 has an age of 160 ka and the mean sedimentation rate is15 cm/kyr (Figure 4-8).Core MD99-2227 shows significant stretching in the upper part of the core, however, thecorrelation to the calibrated ODP Site 983 paleointensity record is possible in the lower part(Figure 4-9). The paleointensity correlation is consistent with the correlation of the plankticoxygen isotope record to the benthic oxygen isotope stack of Lisiecki and Raymo (2005). Thesecorrelations give a basal age for Core MD99-2227 of 430 ka, and mean sedimentation rates of 10cm/kyr (Figure 4-9).Detrital Layer StratigraphyThe ratio of anhysteretic susceptibility to susceptibility (karm/k) has been shown to be auseful magnetite grain size proxy (e.g. King et al., 1983; Tauxe, 1993). Although the plots of karmversus k of each core (Figure 4-4) indicate magnetic grain sizes within a restricted (few micron)range, the karm/k data plotted versus age (Figure 4-10) indicate distinct broad intervals of low

PAGE 82

82values of karm/k that coincide with the early Holocene (when recorded), with MIS 5e, and withthe early parts of MIS 7, 9 and 11 (shaded in Figure 4-10). Low values of karm/k indicaterelatively coarse magnetite grain sizes in these intervals. Although Core JPC18 is missing part ofthe Holocene, and almost the entire MIS 5e, the intervals of low values of karm/k appear to bepartially recorded.Volume magnetic susceptibility data measured on u-channel samples from Cores JPC19and MD99-2227 show an increase in magnetic concentration in the early Holocene, MIS 5e, andin the early parts of MIS 7, 9 and 11 (Figure 4-10). These intervals of high magneticconcentration coincide with the intervals of low values of karm/k (Figure 4-10) that indicaterelatively coarse magnetite grain sizes.In Core JPC15, high sedimentation rates between 20-60 ka (500-1200 cm) allow theidentification of millennial-scale cycles in volume magnetic susceptibility (Figure 4-5). Theseappear to mimic the D/O cycles the Greenland Ice Core (GISP) oxygen isotope record, and arereminiscent of susceptibility cycles identified by Kissel et al. (1999) in cores along the path ofNorth Atlantic Deep Water (NADW), and attributed to changes in the strength of bottomcurrents. The depth of the WBUC, that varies in response to the relative outflows of watermasses from the Greenland and Norwegian Seas, could also be account for the variations.In addition to these broad decimeter-scale intervals defined by karm/k and k values, a totalof seventeen cm-scale layers with magnetic properties and percent carbonate values significantlydifferent from the surrounding sediments have been identified in MD99-2227 (Figure 4-11).These layers have been labeled according to marine isotope stage and their detrital carbonate(DC) content. For example, 6LDC indicates a low detrital carbonate (LDC) layer within MIS 6(Table 4-2).

PAGE 83

83Eight of the seventeen cm-scale layers are designated detrital carbonate layers (DC) on thebasis of their high detrital carbonate contents. Four of these layers (3DC, 7DCa, 8DC, 11DC) arerecognized by coarser grained magnetic material (compared to the background sediment), asindicated by low karm/k values (Figure 4-11). One of these DC layers (7DCa) shows a peak inmagnetic susceptibility while the other seven DC layers do not. Two DC layers (5DC, 9DC)show finer-grained magnetic material (compared to background sediment), and two DC layers(7DCb, 2DC) are not differentiated by magnetic grain size from the background sediment but allDC layers coincide with highs in percent carbonate and six show peaks in GRA bulk density(Figure 4-11). All DC layers are light in color, do not show a sharp base, and appear to showsome bioturbation. The X-radiographs of these layers confirm a high concentration of IRD, butno laminae or evidence for traction (Figure 4-12). Smear slides indicate a high percentage ofcoarse detrital carbonate material in these layers (Table 4-2).Nine of the seventeen cm-scale detrital layers are designated low detrital carbonate (LDC)layers (Figure 4-11). These do not feature an increase in percent carbonate, but show a peak inmagnetic susceptibility, a low in karm/k, and an increase in GRA bulk density. These LDC layersoccur within MIS 1, 2, 5, 6, 7, 9 and 11 and show sharp bases, bioturbated tops and are 4-18 cmthick (Figure 4-11, Table 4-2). The X-radiographs indicate a sharp base and laminae within thelayers (Figure 4-12), some of the laminae are inclined and indicative of traction, implying rapiddeposition from turbidity currents or contourites.Toothpick-sized samples collected at 1cm intervals through detrital layers were used todetermine magnetic hysteresis parameters that can be used as a means of assessing the grain sizeof magnetite (Day et al., 1977). All but one of the detrital layers exhibit hysteresis parametersthat fall within the pseudo-single domain (PSD) grain size range (Figure 4-13). The detrital

PAGE 84

84carbonate layer identified in MIS2 (2DC) shows coarse multi-domain magnetite that isanomalous compared to all other detrital layers (Figure 4-13). For five of the nine LDC layers,we see evidence for progressive change in hysteresis parameters through the detrital layerindicative of grading, fining upward from the base of the layer. Bioturbation of the detrital layerinto the overlying sediment could also cause the layer to appear graded. However, the presenceof distinct laminae within the LDC layers shows that no bioturbation of the layer has occurred.None of the DC layers show this grading in hysteresis parameters. The presence of grading inthe LDC layers indicates a turbiditic rather than a contourite origin for these layers. Smear slides indicate that LDC layers contain little clay and significant amounts of silt-sized opaque grains, green hornblende and quartz. Trace amounts of detrital carbonate arepresent in LDC layers and throughout the rest of the core, whereas the percentage of detritalcarbonate in the DC layers exceeds 10% (Table 4-2).DiscussionSedimentation rates on the Eirik Drift have been shown to be greatly affected by changesin the strength and bathymetry of the Western Boundary Undercurrent (WBUC) that is thoughtto be switched off during glacials and active during interglacials (Hillaire-Marcel et al., 1994;Hillaire-Marcel and Bilodeau, 2000). The core of this current is thought to occupy water depthsbetween 2500 and 3000 meters (Hillaire-Marcel et al., 1994), resulting in winnowing and almostcomplete removal of Holocene and MIS 5e sediment from these depths. Cores from outside theinfluence of the flow would be expected to have interglacial sedimentation rates comparable to,or higher than, glacial sedimentation rates.When combined with previous studies carried out on the drift, the new results indicate thatboth water depth and position on the drift influence interval sedimentation rates. Although thesite of Core JPC18 is located ~450 meters below the supposed core of the WBUC, sediment of

PAGE 85

85Holocene and MIS 5e age is missing at this site. This implies that the WBUC is active at deeperwater depths than previously supposed on the southern side of the Eirik ridge (Figure 4-1). Thismay be consistent with a deep branch of the WBUC, with a gyre in the outer Labrador Sea thatfeeds the Gloria Drift (Figure 4-1).Cores HU90-013-013 (water depth 3471 m), JPC19 (water depth 3184 m) and MD99-2227have relatively high Holocene sedimentation rates of 35 cm/kyr, ~13 cm/kyr, and 10 cm/kyrrespectively. Sedimentation rates in cores MD99-2227 and JPC19 appear to be low at the onsetof deglaciation and then increase. This may be due to increased winnowing by the WBUC at theonset of the deglaciation, offset by increased detrital input as the deglaciation proceeds.Core HU90-013-012 at 2830 meters water depth lies within the influence of the WBUCand has very low sedimentation rates in the Holocene (Stoner et al., 1995a, 1996). Higher up theslope, Core JPC15 at a water depth of 2230 meters has low sedimentation rates in the Holoceneand MIS 5e, although the site supposedly lies outside the main influence of the WBUC. Hillaire-Marcel et al. (1994) noted that, in core HU90-013-06 at even shallower water depths (1105 m)on the Eirik ridge, active bottom currents also resulted in very low Holocene sedimentation rates.Hillaire-Marcel et al. (1994) interpreted DC and LDC layers deposited during the lastglacial cycle at Orphan Knoll, on the western side of the Northwest Atlantic Mid-Ocean Channel(NAMOC), as being related to ice advances of the Laurentide Ice Sheet that triggered turbiditicflows down the NAMOC (Figure 4-1). Sediment suspended by these flows is thought to havedeposited cm-scale sandy mud beds rich in detrital carbonate (DC layers) at Orphan Knoll. Notall the detrital layers observed at Orphan Knoll are recognized on Eirik Drift, although two LDClayers and one DC layer in Core HU90-0130-013 (Figure 4-1) were considered coeval withOrphan Knoll detrital layers (Stoner et al., 1996).

PAGE 86

86The cm-scale detrital layers identified in core MD99-2227 extend the record of detritallayers beyond the last glacial cycle. Detrital layers on Eirik Drift occur during both glacial andinterglacial conditions. However, the layers occurring in the interglacials are close to theTerminations in the Holocene, MIS 5, 7 and 11. It is only in MIS 9 that the DC layer appears tooccur in the later part of the interglacial implying that the Laurentide Ice Sheet was presentthroughout MIS 9.Detrital layer 1LDC with an age of 13 ka in MD99-2227 (Table 4-3) is tentativelycorrelated to DC0 of Stoner et al. (1998). Layer 2LDC has an age of 18 ka and is correlated toDC1 (16 ka) from Orphan Knoll (Stoner et al., 1998) and with H1 of Bond et al., (1999) from thecentral Atlantic. The DC layer 2DC correlates with DC2 of Stoner et al. (1998) and with H2(Bond et al., 1999). The detrital layer labeled 3DC (39 ka) is correlated to DC4 from OrphanKnoll and to H4 (38 ka). As discussed above, the characteristics of LDC layers impliesdeposition by turbidity currents (derived from the Greenland Slope). If so, this turbiditic activityis sometimes coeval with Heinrich layers of the central Atlantic and with detrital events atOrphan Knoll.The ages of layers designated 2LDC, 2DC and 3DC in this study are consistent with agesfor Heinrich events H1, H2, and H4 (Table 4-3). No identifiable events that coeval with Heinrichevents H3, H5 or H6 are found. Hiscott et al. (2001) identified Heinrich-like detrital layers incore MD95-2025 from near Orphan Knoll back to MIS 9. Two detrital carbonate layers withinearly MIS 5 at Orphan Knoll (H8 and H9 of Hiscott et al., 2001) appear to be coeval with DCevents identified on Eirik Drift, implying that instabilities of the Laurentide Ice Sheet arerecorded at both sites. Detrital carbonate layers within MIS 7 and MIS 9 at Orphan Knoll (H10and H13 of Hiscott et al., 2001) are coeval with a LDC layers (7LDC and 10 LDC) identified on

PAGE 87

87Eirik Drift (Table 4-3), implying that the LIS instabilities that triggered the detrital carbonatelayers at Orphan Knoll were coeval with instabilities on the Greenland slope that triggered theLDC layers on Eirik Drift. Such conclusions are highly dependent on the resolution ofstratigraphic correlation. While stratigraphic correlation of detrital layers from the Orphan Knollto the central Atlantic for the last glacial cycle is rather well constrained (Bond et al., 1999;Stoner et al., 1996, 2000), the correlations beyond the last glacial cycle are considerably morespeculative (e.g. Hiscott et al., 2001; van Kreveld et al., 1996) due to lack of stratigraphicresolution that inhibits unequivocal correlation of detrital layers.ConclusionsPiston cores collected from Eirik Drift have produced records of relative paleointensity andof the Laschamp and Iceland Basin polarity excursions that augment oxygen isotope data forgenerating age models. Magnetic data from cores JPC19 and MD99-2227 show broad intervalsof increased magnetic grain size and concentration during MIS 5e and at the MIS 2/1 transition,consistent with observations from Core HU90-013-013 (Stoner et al., 1995b). Core MD99-2227also shows a similar increase in magnetic grain size and concentration at the onset of interglacialMIS 7, 9 and 11, implying that retreat of the Greenland Ice Sheet produced a characteristicdetrital signal at the onset of all interglacial stages over the last 400 kyr.Seventeen cm-scale detrital carbonate and low detrital carbonate layers are identified inMD99-2227 (Figure 4-11, Table 4-2). They occur in both glacial and interglacial stages. Thedetrital layers can be subdivided into two classes. Detrital carbonate (DC) layers are composedof carbonate-rich IRD. They usually, but not always, carry a magnetic signal indicating highmagnetic concentration and increased magnetic grain size relative to background sediment. Lowdetrital carbonate (LDC) layers have <10% detrital carbonate, usually show evidence (frommagnetic hysteresis ratios) for fining-upward grading, and X-radiograph evidence for traction.

PAGE 88

88These layers are also usually marked by high magnetic concentration and increased magneticgrain size relative to background sediment.Based on the differences between DC and LDC layers, we interpret the former as HudsonStrait derived detrital layers, and the latter as layers dominated by material from turbiditesderived from the Greenland slope. 1LDC, 2LDC, 2DC and 3DC are correlative with detritallayers observed at Orphan Knoll (Stoner et al., 1996) (Table 4-3). Three of them (1LDC, 2DCand 3DC) are coeval with central Atlantic Heinrich layers H1, H2 and H4 (Bond et al., 1999).Beyond the last glacial cycle, the correlation of detrital layers from Eirik Drift (this paper) toOrphan Knoll (Hiscott et al., 2001) and to the central Atlantic (van Kreveld et al., 1996) islimited by the imprecision of stratigraphic correlation (Table 4-3). Nonetheless, as illustratedhere, the use of paleointensity-assisted chronostratigraphy, the combination of relativepaleointensity with standard oxygen isotope stratigraphy, improves stratigraphic correlationsacross the northern North Atlantic Ocean (and beyond), and thereby facilitates the interpretationof detrital layers in terms of their correlation, aerial extent and provenance.

PAGE 89

89Table 4-1. Core, latitude, longitude, water depth and base age of the core. Core Latitude Longitude Waterdepth Base age(kyr) JPC15 -45.57 58.20 2230 150 JPC18 -47.13 57.19 3435 300 JPC19 -47.60 57.58 3184 250 MD99-2227 -48.22 58.12 3460 430

PAGE 90

90Table 4-2. DC and LDC layer properties in Core MD99-2227. event Thick-ness(cm) depth(cm) Age(ka) MIS Name kpeak karm/k %carb GRAPEdensity %detr.carb. X-Ray Sharpbase Grading 1 5 440.22 13.04 1/2 1LDC yes coarse low peak 10 traction yes yes 2 14 616.85 18.2 2 2LDC yes coarse low peak trace traction yes yes 3 15 663 21.4 2 2DC no high peak 15 no no 4 21 858.7 39.1 3 3DC no coarse high peak 40 no no 5 6 1872.3 111.68 5 5LDC yes coarse low peak trace yes no 6 16 2019.4 129.34 5 5DC no fine high peak 70 no no 7 14 2192.9 152.17 6 6LDC yes coarse low peak trace traction yes yes 8 16 2505.4 191.58 7 7DCa yes coarse high 20 no no 9 12 2700 214.98 7 7DCb no high peak 25 no no 10 6 2872.3 233.42 7 7LDC yes coarse low peak trace traction yes no 11 11 3083.7 266.57 8 8DC no coarse high peak 20 no no 12 17 3229.2 289.89 9 9DC no fine high peak 30 no no 13 5 3536.4 335.6 9/10 9LDC yes coarse low peak trace traction yes no 14 18 4008.2 391.03 11 11LDCa yes coarse low peak trace traction yes no 15 4 4084.2 403.48 11 11LDCb yes coarse low peak 5 traction yes yes 16 7 4133.7 409.57 11 11LDCc yes coarse low peak 10 traction yes yes 17 7 4240 421.43 11 11DC no coarse high peak 50 IRD rich no no

PAGE 91

91Table 4-3. Detrital Layers from other studies considered to be correlative to detrital layersidentified on Eirik drift. Event Name depth(cm) MD99-2227Age (ka) Stoner et al.(1998)(age ka) H-layers Bondet al. (1999)(age ka) Hiscott et al(2001)(age ka) Van Kreveldet al (1996) (age ka) 1 1LDC 440.22 13.04 DC0 (12) H1(11-12) h1 (15) 2 2LDC 616.85 18.2 LDC1 (18) H1 (16.8) 3 2DC 663 21.4 LDC3 (21) H2 (24) H2 (18-22) h2 (21) 4 3DC 858.7 39.1 DC4 (36) H4 (38) H4 (39-42) h4 (40-43) 5 5LDC 1872.3 111.68 H8(92-108) 6 5DC 2019.4 129.34 H9(121-126) h7 (128-131) 7 6LDC 2192.9 152.17 8 7DCa 2505.4 191.58 h12 (189) 9 7DCb 2700 214.98 10 7LDC 2872.3 233.42 H10(231-240) 11 8DC 3083.7 266.57 12 9DC 3229.2 289.89 13 9LDC 3536.4 335.6 H13(335-340) 14 11LDCa 4008.2 391.03 15 11LDCb 4084.2 403.48 16 11LDCc 4133.7 409.57 17 11DC 4240 421.43

PAGE 92

92 Figure 4-1. Location map showing the Labrador Sea from Hillaire-Marcel and Bilodeau (2000)and the location of piston cores JPC15, JPC18, JPC19, and MD99-2227. Blackarrows indicate the path of the Western Boundary Undercurrent. NAMOC: NorthwestAtlantic Mid-Ocean Channel.

PAGE 93

93 Figure 4-2. Component inclination, corrected component declination and maximum angulardeviation (MAD) values for cores JPC15, JPC19, JPC18 and MD99-2227.

PAGE 94

94 Figure 4-3. a). Component inclination, declination and maximum angular deviation (MAD)values recording Laschamp and Iceland Basin polarity excursions from piston coresJPC15, JPC18 and JPC19. Key: U-channel data (closed circles), deconvolved u-channel data (open squares-dashed line) using the method of Guyodo et al. (2003), 8-cm3 discrete sample cubes (open squares) and 1-cm3 cubes (diamonds).3b).Orthogonal projections from the Iceland Basin excursion from cores JPC19 andJPC18, from u-channel data, deconvolved u-channel data, and discrete samples. Opencircles represent the vector end point projection on the vertical plane. Closed circlesrepresent the vector end point projection on the horizontal plane.

PAGE 95

95 Figure 4-4. Anhysteretic susceptibility (karm) plotted against volume susceptibility (k) for JPC18,JPC19, JPC15 and MD99-2227. Diamonds indicate background sediment, redsquares indicate coarse decimeter-scale interglacial intervals, and blue circles indicatecm-scale detrital layers. Black lines indicate magnetic grain-size boundaries placedusing the calibration of King et al. (1983).

PAGE 96

96 Figure 4-5. NRM, ARM, IRM and volume susceptibility for MD99-2227, JPC15, JPC18 andJPC19. Orange-IRM, green-ARM, red-NRM, blue-volume susceptibility.

PAGE 97

97 Figure 4-6. JPC19: Relative paleointensity record correlated to that from ODP Site 983(Channell et al., 1997; Channell, 1999). Lower plot: planktic "18O data from JPC19correlated to the benthic "18O stack of Lisiecki and Raymo (2005). Intervalsedimentation rates are shown in orange.

PAGE 98

98 Figure 4-7. JPC18: Relative paleointensity data correlated to ODP Site 983 (Channell et al.,1997; Channell, 1999). Lower plot shows planktic "18O data correlated to the benthic"18O stack of Lisiecki and Raymo (2005). Interval sedimentation rates are shown inorange.

PAGE 99

99 Figure 4-8. JPC15: Relative paleointensity data correlated to ODP Site 983 (Channell et al.,1997; Channell, 1999). Lower plot shows planktic "18O data correlated to the benthic"18O stack of Lisiecki and Raymo, (2005). Interval sedimentation rates are shown inorange.

PAGE 100

100 Figure 4-9. MD99-2227: Relative paleointensity data correlated to ODP Site 983 (Channell et al.,1997; Channell, 1999). Lower plot shows planktic "18O data correlated to the benthic"18O stack of Lisiecki and Raymo (2005). Black bar indicates stretched interval dueto coring. Interval sedimentation rates are shown in orange.

PAGE 101

101 Figure 4-10. karm/k and magnetic susceptibility versus age for cores, JPC19, JPC18 and MD99-2227 compared to Core HU90-013-013 (Stoner et al., 1995a). The benthic oxygenisotope stack of Lisiecki and Raymo (2005) is shown at the bottom of the figure.Shaded areas indicate magnetic coarse grain-size intervals (from karm/k) and magneticconcentration intervals (from susceptibility) in early and peak interglacial intervals.

PAGE 102

102 Figure 4-11. Core MD99-2227: karm/k, magnetic susceptibility, bulk (GRAPE) density, percentcarbonate, and planktic oxygen isotope data. Blue shading indicates detrital carbonate(DC) layers and green shading indicates low detrital carbonate (LDC) layers.

PAGE 103

103 Figure 4-12. Photographs and X-radiographs of three detrital layers identified in MD99-2227.Upper: MD99-2227 section 15 (6LDC), middle: MD99-2227 section 28 (11LDCc),and lower: MD99-2227 section 29 (11DC). In X-radiographs, light color indicateshigher density, dark color indicates lower density.

PAGE 104

104 Figure 4-13. Hysteresis ratios Mr/Ms plotted versus Hcr/Hc (after Day et al., 1977): individualdetrital layers from MD99-2227 are shown by colored symbols, with direction ofupward fining indicated by arrow. Black circles indicate background sediment.

PAGE 105

105CHAPTER 5RELATIVE PALEOINTENSITY STACK FOR THE LAST 85 KYR ON A REVISED GISPCHRONOLOGY, AND ENVIRONMENTAL MAGNETISM OF THE GARDAR DRIFTIntroductionFour cores were collected in the summer of 2002 along a NE-SW transect along the GardarDrift, at water depths from 1880 m to 3082 m. Chronologies for the cores were developed usingrelative paleointensity proxies and a benthic oxygen isotope record from the southernmost pistoncore (JPC13). The magnetic grain size proxy karm/k mimics benthic "18O, particularly in thenorthern and southern sites, indicating a link between magnetic grain size and bottom wateractivity. The benthic "18O record from Core JPC13 can be correlated to a similar record fromcore MD95-2042 from the Portuguese Margin, which has been correlated to both the GreenlandIce Core (GISP) and Vostok ice core records. As a result of this correlation, the relativepaleointensity records can be placed on the Shackleton-revised GISP chronology. A stack of 11relative paleointensity records from the North Atlantic region for the 0-85 ka interval has beendeveloped and placed on the revised GISP chronology. This stack (EHC06) shows somesignificant differences particularly in the 0-30 ka interval when compared to the GlobalPaleointensity Stack (GLOPIS). At 60 ka, when compared to both GLOPIS and the NorthAtlantic Paleointensity Stack (NAPIS), there is a difference in the age models of ~2400 years.The EHC06 stack is in better agreement with the independently dated South AtlanticPaleointensity Stack (SAPIS).Sedimentary relative paleointensity (RPI) records can provide important constraints onmechanisms in the geodynamo, can shed light on proposed geomagnetic-climate linkages, andmay provide a means of high-resolution global stratigraphic correlation. High-resolutionchronological control is critical for the study of millennial-scale climate change and RPI recordsprovide a potential means of global high-resolution correlation. When oxygen isotope

PAGE 106

106stratigraphy is combined with RPI records, the combination provides more robust, higherresolution age control than either data set alone. Stacks of RPI records allow the recognition ofregionally characteristic RPI features although the stacking process undoubtedly filters out thehigher frequency components. The North Atlantic Paleointensity Stack (NAPIS) wasconstructed from six relative paleointensity records from the North Atlantic (Laj et al., 2000).Chronological control for the NAPIS stack was based on correlation of the oxygen isotopestratigraphy from Core PS2644-5 to the GISP2 "18O record, allowing the stack to be placed on aGISP2 timescale. The NAPIS stack was augmented by addition of records from the NorthAtlantic, South Atlantic, Indian Ocean and Mediterranean to generate the Global PaleointensityStack (GLOPIS) of Laj et al. (2004). This stack was synchronized with NAPIS, and thereforeplaced on the same GISP2 chronology.Changes over glacial to interglacial cycles in deep and intermediate water circulation mayhave caused changes in the speed of bottom currents that may be detected in magnetic mineralconcentrations and grain size. Magnetic susceptibility and other magnetic concentrationparameters from around the North Atlantic Basin, along the path of NADW, have been shown torecord changes during MIS 3 that can be correlated to Dansgaard-Oeschger (D/O) events in theGreenland ice cores (Kissel et al., 1999). Lower North Atlantic Deep Water (NADW) productionis believed to have increased during interglacials and decreased during glacial periods (Broeckerand Denton, 1989). At the present time, a major contributor to NADW is Iceland-ScotlandOverflow Water (ISOW) that flows across the Gardar Drift from NE to SW at depths of ~1800-3000 meters (Bianchi and McCave, 2000). At deeper water depths (>3000 meters) in thesouthern section of the drift, Lower Deep Water (LDW) of southern hemisphere origin has beenidentified at the sea floor (Bianchi and McCave, 2000) by its high Si content (McCartney, 1992).

PAGE 107

107Upper NADW is found at water depths shallower than 2000 m in the North Atlantic and isdefined by a silicate minimum and salinity maximum (Kawase and Sarmiento, 1986).In this study we present records of relative paleointensity and benthic oxygen isotopesfrom a transect across the Gardar Drift, roughly along the path of NADW that forms a looparound the drift (Figure 5-1). A new relative paleointensity stack has been developed using threenew relative paleointensity records from this work and eight published records (Table 5-1).Magnetic property data show significant changes across the drift that can be related to changingwater masses and bottom current speed.Site LocationsThe Gardar Drift rests on a basement high on the east side of the mid-ocean ridge andstretches for about 1100 km from its northeastern end south of Iceland (<1500 m water depth) tothe southwestern end, just north of the Charlie Gibbs fracture zone (>3000 m water depth)(Bianchi and McCave, 2000) (Figure 5-1). The Gardar Drift is being formed by deposition fromdeep currents transporting detritus from Iceland and the nearby European landmass, therebycreating a smooth, thick, eastward-dipping sediment cover (Bianchi and McCave, 2000). Themain flow of Iceland-Scotland Overflow (ISOW) water travels south of Iceland between waterdepths of 1300 and 2200 meters along the eastern flank of the Reykjanes Ridge and over GardarDrift (McCave and Tucholke, 1986). The Gardar Drift may have been initiated in the late EarlyMiocene between 20 and 17 Ma by a prolonged interval of production of northern componentwater (Miller and Tucholke, 1983). Previous drilling on the Gardar Drift was carried out in 1995during Ocean Drilling Program (ODP) Leg 162, in 1983 during Deep Sea Drilling Project(DSDP) Leg 94, and by a cruise of the RV Hudson in 1991 that collected Core HU91-045-080,close to the coring site of one of the cores discussed here (JPC13).

PAGE 108

108The three cores discussed here were collected on the Gardar Drift in the summer of 2002during a cruise KN166-14 of R/V Knorr that provided site survey data for IODP Expedition 303.The cores were taken in a northeast to southwest transect across the drift (Figure 5-1). Jumbopiston Core JPC13 and accompanying gravity Core GGC12 were taken in a depression at thesouthernmost tip of the Gardar Drift in 3082 m water depth (Table 1). Core JPC2 was taken atthe northern end of the drift close to ODP Sites 984 and 983 in a water depth of 1880 m. CoreJPC5 was taken near the center of the drift in 2841 m water depth (Figure 5-1, Table 5-1). In2004, IODP Expedition 303 revisited the location of Core JPC13 and recovered a sedimentarysection down to 244 meters below seafloor (mbsf) that reached the Olduvai Subchronozone witha mean sedimentation rate of 15 cm/kyr (Channell et al., 2006).Cores JPC2 and JPC5 are typical of sediments deposited on the Gardar Drift during the lastglacial cycle and are dominated by fine silts and silty clays with subsidiary amounts ofnannofossil ooze. Core JPC13, from the southern part of the drift (Figure 5-1), is atypical andcomposed of nannofossil ooze and silty clay interspersed with numerous cmto dm-scaleintervals of diatom-rich sediments. Bodn and Backman (1996) identified diatom rich layers inCore EW93-03-17 (57.0N, 37.0W) from the west side of the Reykjanes Ridge, about 550 kmNW of Core JPC13. They described the laminated diatom ooze as being monospecific and madeup of Thalassiothrix longissima. The same species of diatom was identified at IODP Site U1304(Expedition 303 Scientists, 2006) at the same location as Core JPC13.MethodsU-channel samples were collected from the center of the split face of the jumbo pistoncores and gravity cores. The u-channel samples were measured on a 2-G Enterprises narrow-access long-core magnetometer in a magnetically shielded room at the University of Florida.Volume magnetic susceptibility was measured using a track designed for u-channel samples

PAGE 109

109(Thomas et al., 2002). The natural remanent magnetization (NRM) of u-channel samples wasstepwise demagnetized using peak alternating fields from 10 mT to 50 mT in increments of 5mT, and from 50 mT to 100 mT in increments of 10 mT. Magnetization components werecalculated using the method of Kirschvink (1980) for the 20-80 mT demagnetization interval.Anhysteretic remanent magnetization (ARM) was acquired using a 100 mT alternating field anda 50 !T DC bias field. Isothermal remanent magnetization (IRM) was acquired using a 0.5 Tfield. Both artificial remanences (ARM and IRM) were AF demagnetized at the same peak fieldsas the NRM. Normalized remanence was calculated by the dividing the NRM by either ARM orIRM at each peak demagnetization field and calculating a mean of 9 steps in 20-60 mT interval.The normalized remanence data provide relative paleointensity proxy records that can becorrelated to other cores from the Gardar Drift and the North Atlantic Ocean.Comparison of the volume magnetic susceptibility records from Core GGC12 and CoreJPC13 indicate that the upper part of Core JPC13 is stretched relative to Core GGC12. Toaccount for the stretching, the magnetic susceptibility record from the upper part of Core JPC13was correlated to the susceptibility record from Core GGC12 (Figure 5-2). This correlationgenerated a corrected depth scale for the upper part (0-955 cm) of Core JPC13. For the partsection of Core JPC13 (955-2357 cm), 404 cm was subtracted from the original depth scale,which is the amount by which the upper part of the core had to be shortened to account forobserved stretching.Samples for stable isotope analysis were collected by dissecting the Core JPC13 and CoreGGC12 u-channels into 5-cm intervals after completion of the magnetic measurements. Thesamples were washed and sieved to retain the (>63 m) sand fraction. Isotope analyses werecarried out on the benthic foraminifers Cibicidoides wuellerstorfi and, in the Holocene where C.

PAGE 110

110wuellerstorfi is scarce, Hoeglundina elegans. Benthic foraminiferal tests were cleaned in anultrasonic bath to remove fine-grained particles and soaked in 15% H2O2 to remove organicmatter. Carbon dioxide gas was produced using a Thermo Finnigan Kiel III carbonatepreparation device by reacting foraminiferal calcite with 3 drops of H3PO4 at 90C. Oxygenisotope ratios were measured on-line using a Thermo Finnigan MAT252 mass spectrometer. Allisotope results are reported in standard delta notation relative to Vienna Pee Dee Belemnite(VPDB). Analytical precision was estimated by repeated measurements of NBS-19 and was 0.06 for "18O. Both C. wuellerstorfi and H. elegans were corrected to isotopic equilibriumusing the corrections of +0.64 and -0.4 respectively (Shackleton et al., 1984). A compositesection using data from both cores was produced by splicing the isotope record from CoreGGC12 to Core JPC13 at a depth of 274 cm.Gamma ray attenuation bulk density (GRA bulk density) for Core JPC13 was measured ona GEOTEK multi-sensor core logger using u-channel samples. The calibration standard for GRAbulk density measurements was specially constructed for u-channel samples.Directional Magnetic DataOrthogonal projections of NRM data from all four cores show well-definedmagnetization components on vector end-point projections (Figure 5-3), with less than 5% of theNRM remaining after demagnetization at peak fields of 100 mT. Maximum angular deviation(MAD) values for component magnetization directions resolved in the 20-80 mTdemagnetization interval are generally below 5 (Figure 5-4). Diatom mats in Core JPC13(shaded intervals in Figure 5-4) occasionally show a high coercivity component that is notdemagnetized at peak fields of 100 mT (sample JPC13, section 4 in Figure 5-3). We attribute thisto an ARM acquired during the NRM demagnetization procedure possibly due to the presence ofultra-fine magnetite susceptible to the acquisition of ARM. Two intervals between 300-315 cm

PAGE 111

111and 1600-1920 cm in Core JPC13 show shallower than expected inclination values. Theseintervals coincide with thick layers of diatom mats, and magnetization directions may beinfluenced by spurious ARM acquisition during the NRM demagnetization, as mentioned above.Normalized RemanenceIn the absence of secondary remanence acquisition, NRM intensity of sediments dependson the intensity of the geomagnetic field at time of deposition, magnetic mineralogy, grain sizeand concentration of the magnetic remanence carriers. To produce a proxy for geomagnetic fieldintensity, the effects of down-core changes in magnetic concentration must be removed.Assuming that the magnetization is carried by single domain or pseudo single domain magnetite,we can use artificial remanences such as ARM and/or IRM to normalize for the changes in theconcentration of magnetic carriers. Tauxe (1993) stipulated that for sediments to be consideredsuitable for paleointensity studies, they must be relatively homogeneous. Magnetic susceptibilityin these cores does not change by more than an order of magnitude. Anhysteretic susceptibility(karm) plotted versus susceptibility (k) indicates uniform magnetite grain sizes in the 1-5 mrange for all three cores fining southward with Core JPC13 having the finest grain sizes (Figure5-5).Two relative paleointensity proxies (NRM/ARM and NRM/IRM) were calculated for eachof the cores from a mean of nine demagnetization steps in the 20-60 mT demagnetizationinterval. The two proxies for each of the four piston cores were normalized to 1 and compared(Figure 5-6). NRM/IRM shows departures from the NRM/ARM proxy in some intervals such asthe 1300-1450 cm interval of Core JPC5, although the shape of the curve is similar for bothpaleointensity proxies. We attribute these departures to finer magnetic grain sizes in theseintervals, as indicated by karm/k values.

PAGE 112

112Stable Isotope Data and Age ModelsThe age model for Core JPC13 was derived from the oxygen isotope stratigraphy bycorrelation to Core MD95-2042 (Shackleton et al., 2004). Core MD95-2042 was collected on thePortuguese margin at 37'N, 10'W in a water depth of 3146 m during the 1995 IMAGEScruise (Bassinot et al., 1996). A useful feature of this core is that the planktic "18O record isremarkably similar to the GISP ice-core "18O record (Figure 5-7). Shackleton et al. (2004)employed this correlation to obtain a revised GISP chronology by utilizing AMS14C ages offoraminifera in Core MD95-2042 calibrated using paired 14C and 230Th measurements on pristinecorals for the younger part of the record, and speleothems at the older end of MIS 3. Hereafter,we refer to this chronology as the Shackleton-revised GISP chronology.As the benthic oxygen isotope record from Core JPC13 can be satisfactorily correlated tothe benthic oxygen isotope record from Core MD95-2042 (Figure 5-7), the Shackleton -revisedGISP chronology can be applied to Core JPC13. This chronology can then be extended to CoresJPC2 and JPC5 using relative paleointensity correlations (Figure 5-8). Interval sedimentationrates (Figure 5-9), consistent with the Shackleton-revised GISP chronology, were calculated forCore JPC13 by correlation to Core MD95-2042 (through benthic "18O), and for Cores JPC2 andJPC5 by correlation to Core JPC13 (through relative paleointensity, Figure 5-8).Bulk Magnetic and Physical ParametersAnhysteretic susceptibility was calculated every cm down-core by normalizing the ARMby the DC bias field used to apply the ARM. ARM was then divided by the volume susceptibilityto calculate the magnetite grain size proxy karm/k for Core JPC13 (Figure 5-10). When karm isplotted versus k, using the calibration of King et al. (1983), the mean grain-sizes from all threecores can be seen to fall within a restricted range, usually less than 5 !m (Figure 5-5).

PAGE 113

113Diatom-rich sediments in Core JPC13 (shaded in Figure 5-10) are associated with MIS 5,with thin diatom-rich layers distributed within MIS 1-3. Diatom-rich intervals correspond toreduced values of susceptibility, lower and more variable density values, and relatively fine-grained magnetite as indicated by trends in karm/k (Figure 5-10). Volume magnetic susceptibilityshows decreasing values southward along the drift that can be attributed to biogenic dilution(Figure 5-11d).In Core JPC2, karm/k data can be correlated to the benthic oxygen isotope record from ODPSite 983 (Figure 5-11a), indicating that magnetite grain size at this site is varying with isotopicstage and changing abruptly at Termination I and II. Coarser magnetite grain sizes characterizethe interglacial intervals and finer grain sizes characterize the glacial intervals. Core JPC13, onthe other hand, shows a different pattern (Figure 5-11c) in which karm/k is positively correlated tothe benthic oxygen isotope record from the same core during MIS 3. Finer magnetite grain sizesoccur in the interglacials and interstadials, and coarser grain sizes in the glacials and stadials(Figure 5-11c). In Core JPC5, a similar positive correlation is only observed the later part ofMIS 5 (Figure 5-11b).Relative Paleointensity StackA stack of eleven North Atlantic relative paleointensity records has been developed usingthe records from Cores JPC2 and JPC5, as well as Core JPC13 to place the stack on the revisedGISP age model (Shackleton et al., 2004). The seven published records used to augment thestack (Figure 5-12 and Table 5-2) were chosen based on the presence of an isotopic age modelfor each record, and a correlation coefficient for each record to JPC13 of > 0.5. Although CoresJPC2 and JPC5 do not have independent isotopic age models, their relative paleointensityrecords correlate to that from Core JPC13 with a correlation coefficient exceeding 0.6 (Figure 5-8). The records were then normalized to 1 by dividing by the mean of the paleointensity proxy.

PAGE 114

114Each record was then optimally correlated to the relative paleointensity proxy from Core JPC13to place them on the Shackleton-revised GISP chronology. The resulting correlation was thenchecked for any violations of the individual isotopic age models. The records were then re-sampled at an even spacing of 500 years. An arithmetic mean of the eleven records wascalculated along with the standard deviation. A jack-knife test was used to assess errors on thestack in which each record was, in turn, excluded from trial stacks. The departure of the trialstacks from the mean value of the stack yields the estimate of standard deviation for the finalstack (Figure 5-13). Only seven of the sites used in the stack have Holocene relativepaleointensity records.The EHC06 stack, on the Shackleton-revised GISP age model generated through CoreMD95-2042, was then compared with the 30-100 ka 36Cl record from the GRIP ice core(Baumgartner et al., 1998) and with the 0-60 ka 10Be-derived paleointensity estimate (Muscheleret al., 2005), both placed on the GISP2 chronology (Figure 5-14). The stack shows minor offsetswith respect to the 10Be-derived paleointensity estimate in the 0-50 ka interval, and larger offsets(to older ages) with respect to the 36Cl record beyond 50 ka. These offsets are broadly consistentwith, and in the same sense as, the offsets between the revised GISP chronology and the standardGISP2 chronology (Shackleton et al., 2004). When the EHC06 stack is compared to the NAPISstack (Laj et al., 2000), similar offsets are observed (Figure 5-15). The NAPIS stack was placedon the GISP2 chronology using the marine to ice-core oxygen isotope correlation proposed byVoelker et al. (1998) from Core PS2644. The age of the paleointensity low associated with theLaschamp excursion differs by ~300 years in the two stacks, and the difference in age ofpaleointensity features increases to 1870 years at the ~ 60 ka paleointensity low (Figure 5-15).These age differences are very consistent with offsets between the Shackleton-revised GISP

PAGE 115

115chronology and the GISP2 chronology of Meese et al. (1997) (see Table 2 of Shackleton et al.,2004). Major differences between EHC06 and NAPIS occur in the 10-20 ka interval where theNAPIS stack shows a peak while the EHC06 stack shows a low, and between 42-50 ka where apeak in the NAPIS stack is not seen in the EHC06 record.The global GLOPIS stack (Laj et al., 2004) covers the 0-75 ka interval (Figure 5-15).EHC06 shows a good match to GLOPIS apart from the 0-12 ka interval where GLOPIS utilizesthe archeomagnetic data of Yang et al. (2000). GLOPIS shows an upward trend from 20 ka topresent that is not seen in EHC06, however, both records show a double peak in the Holocene(Figure 5-15). Comparison to the South Atlantic SAPIS stack (Stoner et al., 2002) indicates agood match in the 30-70 ka. However, in the 20-30 ka interval, the new stack shows a peakwhere SAPIS shows a significant paleointensity low (Figure 5-15). SAPIS is on a chronologyindependent of GISP and fits better with EHC06 than with either NAPIS or GLOPIS between 45ka and 70 ka. The SAPIS chronology was based on the age model for ODP Site 1089 (Hodell etal., 2001) that was constructed by correlating planktic and benthic isotope records to those fromCore RC11-83 which has 14 calibrated radiocarbon ages in the 11-41 ka interval (Charles et al.,1996).Environmental MagnetismSediment sorting takes place through differing rates of sediment transport so that anoriginally unsorted mixture is converted downstream into narrower grain size distributions(McCave et al., 1995). Sediments from the transect along the Gardar Drift show magnetic grainsizes in a restricted range indicative of sorting and deposition by bottom currents, with atendency for fining to the south accompanied by reduction in magnetic concentration (Figures 5-5 and 5-11d). Current sorting of sediment is thought to take place largely in the 10-63 m rangeor sortable silt grain-size fraction (McCave et al., 1995). Below this grain-size range, sediments

PAGE 116

116are dominantly cohesive as clay minerals (with their charge imbalances) enter the sedimentscompositional spectrum, and van der Waals forces play an important role in particle adhesion(McCave et al., 1995). Although the magnetic grain sizes estimated from karm /k values arelargely in the 1-5 m range, the karm/k ratio may be influenced by the coarsest magnetic grains inthe grain size population and these grains may lie in the sortable silt fraction.In Core JPC2, from the northern end of the Gardar Drift, coarser magnetic grain sizesoccur during interglacials whereas the finer magnetite is present in the glacials (Figure 5-11a).The magnetic grain size at this site shows a progressive coarsening down-core through MIS 3,fining in MIS 4 and coarsening in MIS 5. The location of Core JPC2, at 1880 m water depth, ispresently under the influence of ISOW (Bianchi and McCave, 2000). We interpret the karm/k datato indicate stronger ISOW bottom currents during interglacials that winnow finer sedimentleaving coarser material. In the glacials, slower ISOW current strength allows deposition of finerparticles. ISOW is an important precursor of NADW, therefore, the grain size data from CoreJPC2 implies increased NADW production during interglacials relative to glacial stages.Bianchi and McCave (2000) divided the Iceland Basin into two areas, north and south of58 30 N, based on studies of surface sediments. North of this boundary, the Gardar Drift isdraped by sediments with high (terrigenous) silt/clay ratio, containing abundant current-sortedsilt with a strong coarse-grained modal peak. They ascribed this coarser grain-size to the strengthof the near-bottom current flow, and the proximity of Iceland, consistent with the coarser grainsizes identified in the Holocene sediments in Core JPC2.In sediments from the Reykjanes Ridge, Snowball and Moros (2003) identified a saw-toothed pattern in magnetic grain size in MIS 3 during Dansgaard-Oeschger (D/O) cycles withmagnetic grain-sizes coarser during interstadials compared to stadials. The changes in magnetite

PAGE 117

117grain size were interpreted as a proxy for the speed of near-bottom currents, with a gradualintensification in current velocity followed by a sharp decrease. While these short-term changesare not identified in sediments from Core JPC2, the changes in current speed (faster currents inwarm periods and slower current in cold periods) are consistent with the changes seen in CoreJPC2. The short-term saw-toothed pattern in magnetic grain size identified by Snowball andMoros (2003) is superimposed upon a long-term trend of reduced current speed (finer grainsizes) leading up to the Last Glacial Maximum (LGM), similar to the trend seen in Core JPC2.In Core JPC5, magnetic grain size does not show a correlation to the benthic oxygenisotope record of either ODP Site 983 or Core JPC13 (Figure 5-11b), but the magnetic fraction isfiner-grained than Core JPC2 and coarser grained than Core JPC13 (Figure 5-11). This isindicative of transport by deep currents from a single source manifest by the decrease inconcentration and grain size as the currents move southward from the principal detrital source. Asimilar trend was noted by Ballini et al. (2006) along the path of NADW from just north of theFaeroe Shetland channel, to near the Reykjanes Ridge and into the Irminger Basin. The karm/kmagnetic grain size in Core JPC5, which is at a water depth of 2841 m, does not show acorrelation to the benthic isotope records, other than in the later part of MIS 5, and this mayindicate that the site is seeing a mixture of both LDW and ISOW.Core JPC13 was collected at deeper water depths (3082 m) than either Cores JPC2 or JPC5and shows the finest magnetic grain sizes of any of the sites (Figure 5-5 and 5-11). In MIS 3, themagnetic grain size proxy can be correlated to the benthic isotope record from the same core(Figure 5-11c). The oxygen isotope record from Core JPC13 can, in turn, be correlated to the "Drecord of the Vostok ice core (Jouzel et al., 1987), which reflects temperature variations overAntarctica (Figure 5-7). This implies that during the last glacial period the benthic oxygen

PAGE 118

118isotopes are recording water temperatures that reflect the Antarctic temperature record. TheAntarctic climate events A1, A2, A3 and A4 (Figure 5-7) are clearly recorded in the benthicisotope record from Core JPC13, suggesting that a water mass of southern hemisphere origin wasbathing the site during MIS 3 precluding the hypothesis that changes sediment source couldaccount for the grain size changes identified in the karm/k record. Magnetic grain size as indicatedby karm/k is coarser during Antarctic Interstadials A1-A4 indicating faster bottom currents (andpossibly increased flux of lower deep water (LDW) of Southern Hemisphere origin into theNorth Atlantic) during Antarctic warm events. During interglacials, the correlation of the benthic"18O record to the magnetic grain size record breaks down and the record shows some similarityto the Greenland Ice core record indicating changes in the bottom-water mass over the site(Figure 5-7).ConclusionsThe new EHC06 relative paleointensity stack of eleven records from the North Atlanticregion has been placed on the revised GISP chronology of Shackleton et al. (2004). This stackshows a good correlation with other paleointensity stacks (such as GLOPIS) indicating that thenew stack is providing a consistent representation of relative geomagnetic field intensity. Itshould be noted that three records utilized by EHC06 are also used in NAPIS and seven of therecords were used in GLOPIS, although the age model for EHC06 is not the same as for theother stacks. The previous North Atlantic stacks (NAPIS and GLOPIS) are placed on GISP agemodels by correlation of magnetic concentration parameters to Core PS-2644 (Kissel et al.,1999), and the "18O correlation from this core to GISP (Voelker et al., 1998). The age offsetsbetween EHC06 and NAPIS/GLOPIS are consistent with the age offsets between the GISPchronology and the Shackleton-revised GISP chronology (see Table 2 in Shackleton et al., 2004),

PAGE 119

119indicating consistency in age models. In the 45-70 ka interval, the Shackleton-revised GISPchronology applied to the EHC06 stack is more consistent with the age model for the SAPISstack, which is independent of GISP (Stoner et al., 2002), than with the NAPIS/GLOPIS agemodels that are tied to GISP chronologies. For the Holocene, EHC06 shows a double peak in theHolocene (0-12 ka), which compares well with the archeomagnetic stack of Yang et al. (2000)and with available lake sediment records for this interval (e.g. Snowball and Sandgren, 2004),although the scaling in this interval differs from that adopted in GLOPIS (Figure 5-15).Magnetite grain size, based on the parameter karm/k, shows a correlation to the benthicoxygen isotope records for Cores JPC13 and JPC2. Core JPC2 lies at 1880 m water depth and isbathed in ISOW. The karm/k values at Core JPC2 show coarser magnetic grain sizes in theinterglacials (faster bottom currents) and finer magnetic grain sizes in the glacials (slower bottomcurrents) with a trend from coarse to fine through MIS 3 indicating decreasing bottom watercurrent strength. Core JPC5 (2841 m water depth) does not exhibit a clear correlation betweenthe oxygen isotope record and the magnetic grain size implying the site is seeing some mixtureof ISOW and LDW. Core JPC13 is the deepest of the sites on the drift, and shows the finestmagnetic grain sizes. In MIS 3, the magnetic grain size record can be correlated with the benthicisotope record that in turn can be correlated to the Vostok ice core air-temperature record. Thebenthic isotope record in Core JPC13 appears to be recording bottom water temperatures that arelinked to Vostok air temperature, implying LDW of southern ocean origin. The link to karm/kindicates that magnetic grain size (and hence bottom current strength) also changes in concertwith bottom-water temperatures.

PAGE 120

120Table 5-1. Summary of the cores used in this study and the eleven cores used in the relativepaleointensity stack, including latitude, longitude, water depth, mean sedimentationrates and references. Core Latitude Longitude Sedimentation rates(cm/kyr) Water Depth(meters) Reference JPC2 61.04 N 22.92 W 8 1880 This work JPC5 56.35N 27.86 W 17 2841 This work JPC13 53.05 N 33.53 W 15 3082 This work HU90-013-012 58.92 N 47.12 W 8 2830 Stoner et al., 1995 HU90-013-013 58.20 N 48.37 W 12 3380 Stoner et al., 1995 MD95-2024 50.20 N 45.68 W 24 3448 Stoner et al., 2003 MD95-2009 62.73 N 03.98 W 21.5 1027 Laj et al., 2000 ODP Site 984 61.40 N 24.10 W 18.7 1995 Channell 1999 ODP Site 983 60.40 N 23.63 W 10.8 1660 Channell et al., 1997 ODP Site 919 62.67 N 37.47 W 15 2088 Channell, 2006 PS2644-5 67.87 N 21.77 W 12.4 777 Laj et al., 2000

PAGE 121

121 Figure 5-1. Location map for cores analyzed in this study (JPC2, JPC5 and JPC13) and thelocation of cores used in the paleointensity stack (modified after Raymo et al., 2004).Paths of major deep-water flows are indicated by arrows. Key: NADW-NorthAtlantic Deep Water, ISOW, Iceland Scotland Overflow Water, DSOW-DenmarkStrait Overflow Water, LSW-Labrador Sea Water, LDW-Lower Deep Water. P13-Core HU90-013-013, P12-Core HU90-013-012.

PAGE 122

122 Figure 5-2. a) Correlation of the magnetic susceptibility records from Core GGC12 and CoreJPC13 with tie-lines to show the correlation between the two cores. b) Magneticsusceptibility records from Core GGC12 and Core JPC13 after adjustment to accountfor the stretching in Core JPC13.

PAGE 123

123 Figure 5-3. Orthogonal projections of alternating field demagnetization data from Cores JPC2,JPC5 and JPC13. Open circles indicate the vector end-point projections on thevertical plane, closed circles indicate the vector end-point projection on the horizontalplane.

PAGE 124

124 Figure 5-4. Component inclination, declination and maximum angular deviation (MAD) valuesfor Cores JPC2, JPC5, and JPC13. Shading for Core JPC13 indicates the position ofdiatom-rich intervals. Inclination is shown by a black line, declination by blue dots,and MAD values by a red line.

PAGE 125

125 Figure 5-5. Plot of anhysteretic susceptibility (karm) versus volume susceptibility (k), opensquares represent Core JPC13, closed diamonds Core JPC5 and crosses Core JPC2.

PAGE 126

126 Figure 5-6. Paleointensity proxies: Mean NRM/ARM (red line) and mean NRM/IRM (blackline) versus depth compared for Cores JPC2, JPC5 and JPC13.

PAGE 127

127 Figure 5-7. Core JPC13 benthic oxygen isotope record (blue line), open circles indicate datafrom Core GGC12, correlated to the MD95-2042 benthic oxygen isotope record (redline) of Shackleton et al. (2004), and the Vostok ice core "D record (Jouzel et al.,1987), (on the revised GISP age model of Shackleton et al., 2004) (black line). Alsoshown is, the MD95-2042 planktic isotope record (green line) of Shackleton et al.(2004) and the GISP "18O ice core record (Grootes et al., 1997) (on the GISP2 agemodel of Meese et al., 1997).

PAGE 128

128 Figure 5-8. Relative paleointensity records from Cores JPC2, JPC5 correlated to Core JPC13 onthe revised GISP chronology (Shackleton et al., 2004) for the last 85 ka. The CoreJPC13 record is shown in blue, the Core JPC5 record in red and the Core JPC2 recordin green.

PAGE 129

129 Figure 5-9. Interval sedimentation rates for Cores JPC2, JPC5 and JPC13. The sedimentationrates for Core JPC13 were calculated using the correlation between the benthicisotope records, and the sedimentation rates for Cores JPC5 and JPC2 were calculatedbased on the correlation of the relative paleointensity records.

PAGE 130

130 Figure 5-10. Core JPC13: GRA bulk density (orange), anhysteretic susceptibility divided byvolume magnetic susceptibility (karm/k) (red), magnetic susceptibility (k) (purple), andbenthic oxygen isotope data from Core JPC13 (black closed symbols) and GGC12(open squares). Shaded intervals indicate diatom-rich sediment.

PAGE 131

131 Figure 5-11. a) Anhysteretic susceptibility divided by volume magnetic susceptibility (karm/k)from Core JPC2 (red line) plotted against the benthic "18O record (black line) fromODP site 983 (Channell et al., 1997). b) Anhysteretic susceptibility divided byvolume magnetic susceptibility (karm/k) from Core JPC5 (red line), with inverted scalerelative to (a), plotted against the benthic "18O record (black line) from ODP Site 983(Channell et al., 1997). c) Anhysteretic susceptibility divided by volume magneticsusceptibility (karm/k), with inverted scale relative to (a), plotted against the benthic"18O record for Core JPC13. d) Magnetic susceptibility for Core JPC2 (top), CoreJPC5 (middle) and Core JPC13 (bottom) showing the decrease in susceptibility fromNE to SW along the drift.

PAGE 132

132 Figure 5-12. Eleven relative paleointensity records from the North Atlantic Ocean used in thenew EHC06 stack (see Table 2 for references). The records have been correlated toCore JPC13 to place them on the revised GISP chronology (Shackleton et al., 2004)and then re-sampled at a 500-year interval.

PAGE 133

133 Figure 5-13. a) The new relative paleointensity stack (heavy black line) with the results of thejack-knife sampling. b) The eleven records used in the relative paleointensity stackplotted together on the revised GISP chronology (Shackleton et al., 2004).

PAGE 134

134 Figure 5-14. Comparison of the EHC06 paleointensity stack to 36Cl flux (red line) (Baumgartneret al., 1997) and the paleointensity estimate based on the 10Be flux (blue line)(Muscheler et al., 2005), from the GRIP and GISP Greenland ice cores, respectively.

PAGE 135

135 Figure 5-15. Comparison of the EHC06 paleointensity stack (black line) on the revised GISP age(Shackleton et al., 2004) to other paleointensity stacks: a) NAPIS (Laj et al., 2000), b)GLOPIS (Laj et al., 2004) and c) SAPIS (Stoner et al., 2002) (red lines).

PAGE 136

136CHAPTER 6RELATIVE GEOMAGNETIC PALEOINTENSITY IN THE GAUSS AND GILBERTCHRONS FROM IODP SITE U1313 (NORTH ATLANTIC)IntroductionIntegrated Ocean Drilling Program (IODP) Site U1313 (41.068 N, 32.44' W)constitutes a reoccupation of Deep Sea Drilling Project (DSDP) Site 607 located at the base ofthe upper western flank of the Mid-Atlantic Ridge, ~240 miles northwest of the Azores Islands,in a water depth of 3426 m (Figure 6-1). DSDP Site 607 utilized the hydraulic piston corer(VLHPC) and the Extended Core Barrel (XCB) to penetrate to a total depth of 311.3 metersbelow seafloor (mbsf) (Ruddiman, Kidd, Thomas, et al., 1987). DSDP Sites 607 and 609 (bothdrilled during DSDP Leg 94) constitute benchmark sites for the long-term (Myr) surface anddeep ocean environmental records from the sub-polar North Atlantic (Ruddiman et al., 1986;Raymo et al., 1989). Drilling of DSDP Leg 94 sites preceded the shipboard capability forconstruction of composite sections and continuous measurement of magnetic parameters withpass-through magnetometers. The magnetostratigraphy from Site 607 was based on discretesamples (Clement and Robinson, 1987), and indicated a clear sequence of reversals to the base ofthe Matuyama Chronozone, with poor definition of polarity zones in the Gauss and GilbertChrons.Four holes (Holes U1313A-D) were cored with the Advanced Piston Corer (APC) usingnon-magnetic core barrels to maximum depths of 308.6, 302.4, 293.4, and 152.0 mbsf,respectively, with an average recovery of 103.5% (Expedition 306 Scientists, 2006). TheHolocene to uppermost Miocene sedimentary succession at Site U1313 comprises nannofossilooze with varying amounts of foraminifers and clayto gravel-sized terrigenous components.Two major lithologic units were identified. Unit I consists of Holocene to Upper Pliocenealternating nannofossil ooze, silty clay nannofossil ooze, and nannofossil ooze with clay. Unit II

PAGE 137

137consists of Upper Pliocene to uppermost Miocene nannofossil ooze, characterized by high(~95%) and uniform carbonate concentrations. The shipboard magnetic stratigraphy at SiteU1313 was constructed on the basis of continuous measurements of natural remanentmagnetization (NRM) after AF demagnetization at peak fields of 20 mT. NRM intensities after20 mT peak field demagnetization are in the 10 to 10 A/m range above 150 mbsf, and fall tothe 10 to 10 A/m range in the lower part of the section (150-275 mbsf).U-channel samples collected post-cruise have allowed refinement of the shipboardmagnetic stratigraphy at Site U1313. The polarity stratigraphy can now be resolved for theGauss and Gilbert Chrons, and for the latest Miocene, down to ~285 meters composite depth(mcd). The nannofossil oozes have a weak low-coercivity magnetization carried by magnetite.Although volume magnetic susceptibility is weak and partially negative, it is reproducible asdemonstrated by replicate measurements on u-channel samples. Natural gamma radiation andreflectance data, collected shipboard on whole core sections, and magnetic susceptibility from u-channel samples can all be correlated to the benthic oxygen isotope stack of Lisiecki and Raymo(2004). The age model for Site U1313 is based on the correlation of the u-channel magneticsusceptibility record to a benthic oxygen isotope stack and, in part, to the astronomic solution forinsolation. The resulting reversal ages are consistent (within one obliquity cycle) withestablished reversal ages in current polarity timescales. Three relative paleointensity proxies(slopes of NRM/ARM, NRM/IRM, and NRM/ARM-acquisition) are broadly consistent witheach other, can be correlated to Pacific and Indian ocean records of the same age, and show littleevidence for the saw-tooth pattern of paleointensity decrease, observed in other records of thesame age.

PAGE 138

138MethodsAt Site U1313, u-channel samples (2x2 cm square cross-section and 150 cm in length)were collected from the center of the split face of core sections in the 120-285 meters compositedepth (mcd) interval of the shipboard-derived composite section that corresponds to the 2.4-6.2Ma interval. The natural remanent magnetization (NRM) of u-channel samples was measuredeach 1-cm down-section on a 2G-Enterprises pass-through cryogenic magnetometer at theUniversity of Florida. From 120 mcd to 170 mcd, the NRM of u-channel samples was AFdemagnetized in the 20-60 mT interval using 5 mT increments. Below 170 mcd, the weakmagnetization intensities led to the NRM being demagnetized in 2.5 mT increments in the 20-40mT peak field range. Volume susceptibility was then measured each 1-cm down-section using asusceptibility track specifically designed for u-channel samples that has a measurementresolution of a few centimeters (Thomas et al., 2003). The volume susceptibility values are verylow, but repeatable, varying in the -10-2 to 10-2 (SI) range. The mean of three replicatemeasurements, and the resulting standard deviation, constituted the susceptibility record.Anhysteretic remanent magnetization (ARM) was applied using an AF field of 100 mT anda bias DC field of 50 !T. Isothermal remanent magnetization (IRM) was imparted using a 0.5 TDC field. Both artificial remanences were demagnetized with the same AF steps used todemagnetize NRM. ARM acquisition was also measured for the 120-170 mcd interval usingincreasing AF peak fields in 5 mT increments in the 20-60 mT peak field range, and a bias DCfield of 50 !T.In the 120-170 mcd interval, principal components were calculated from the NRM datausing the method of Kirschvink (1980) applied to the 20-60 mT demagnetization interval. In thelower part of the section, below 170 mcd, a single demagnetization step (30 mT) was generallyused to determine the characteristic magnetization due to the weak magnetization intensities that

PAGE 139

139precluded the definition of magnetization components. NRM data were normalized by ARM,ARM-acquisition, and IRM to generate relative paleointensity (RPI) proxies. For the 120-170mcd interval, slopes of NRM/ARM and NRM/IRM were calculated for each measurementposition (each 1-cm) in the 20-60 mT peak field range. The linear correlation coefficient (R)provided a measure of the uncertainty in the value of the slope. Similarly, for normalization byARM-acquisition, the slope of the NRM-lost vs ARM-gained plot was calculated together with alinear correlation coefficient (R). The paleointensity proxy based on ARM-acquisition isanalogous to the pseudo-Thellier method of Tauxe et al. (1995). From 170 to ~245 mcd,NRM/ARM and NRM/IRM values were calculated using the mean of 5 values of the ratio,calculated for 5 demagnetization steps in the 20-30 mT interval (2.5 mT increments).ResultsThe magnetic polarity stratigraphy at IODP Site U1313, that is reported here, covers theinterval between the Miocene-Pliocene boundary and the onset of the Matuyama Chron. Thepolarity subchrons: Kaena, Mammoth, Cochiti, Nunivak, Sidujfall, and Thevra are all clearlydefined (Figures 6-2 and 6-3, Table 6-1), however, below ~250 mcd, polarity zones are poorlydefined. The age of the base of the u-channeled section is Late Miocene (~6.2 Ma).NRM intensities (prior to demagnetization of u-channel samples) are weak, lying in the 10-3-10-4 A/m range in the 120 mcd-170 mcd interval, and in the 10-4-10-5 A/m range below 170mcd (Figures 6-2 and 6-3). Magnetization components can be adequately defined down to 170mcd, as indicated by orthogonal projections of demagnetization data (Figure 6-4), and maximumangular deviation (MAD) values that accompany component magnetizations (Figure 6-2). In thelower part of the section, magnetization components could not be adequately resolved fromorthogonal projections because there is no systematic decrease in magnetization intensity to the

PAGE 140

140origin of the projection. The definition of the characteristic magnetization in this interval wasbased on a single demagnetization step (30 mT peak field). An initial age model was based onthe location of polarity reversals, the polarity timescale of Cande and Kent (1995), and theassumption of constant sedimentation rates within polarity chrons, yielding interval meansedimentation rates of 3-6 cm/kyr (Figure 6-5).Normalized remanence values (RPI proxies) were calculated using three normalizers:demagnetized ARM, demagnetized IRM, and ARM-acquisition. At each 1-cm interval, in the120-170 mcd interval, the normalized remanence values were calculated by determining theslopes of NRM versus the normalizer, in the 20-40 mT AF peak field range (Figure 6-6). Thelinear correlation coefficient (R) of the slope yields a measure of the uncertainty in the definitionof the slope. Although the three RPI proxies show similar variability, the NRM/ARM andNRM/ARM-acquisition records show anomalously high values, particularly in the 120-130 mcdinterval and at about 153 mcd (Figure 6-6). The NRM/IRM record does not show theseanomalous values, and was therefore used as the Site U1313 RPI proxy for comparison withother RPI records.Anhysteretic susceptibility divided by susceptibility (karm/k) is sensitive to magnetite grainsize, with high values indicating finer grains. The magnetite grain size proxy was calculated forthe 120-160 mcd interval where susceptibility values are positive. The karm/k values indicatethat, in intervals where the NRM/ARM and NRM/ARM-acquisition RPI proxies areanomalously high, the magnetite grain size is apparently relatively coarse (shaded intervals inFigure 6-7). These intervals are coincident with the darker (glacial) intervals in the section,implying the presence of coarser magnetic material, possibly ice rafting debris (IRD), during theglacial intervals. This interpretation is supported by other magnetic properties: ARM is very

PAGE 141

141weak in the affected intervals, and the IRM intensities are also relatively low. Magneticsusceptibility values in these intervals are, however, consistent with the surrounding sediment,consistent with the magnetite in these intervals being anomalously coarse grained.In the 170-220 mcd interval, NRM components could not be adequately defined because ofthe very weak NRM intensities (Figures 6-2 and 6-3). For this interval, we plot mean values forNRM/ARM and NRM/IRM for five demagnetization steps (2.5 mT increments) in the 20-30 mTpeak field range (Figure 6-8). The standard deviation about the mean gives a measure of thevariability in normalized remanence values in this demagnetization range.The RPI record (NRM/IRM) from IODP Site U1313 can be correlated to the East Pacificpaleointensity stack (EPAPIS) of Yamazaki and Oda (2005) back to 3 Ma, to the Valet andMeynadier (1993) record from the Pacific Ocean (ODP Leg 138) back to 4 Ma, and to the IndianOcean record (Core MD90-0940) of Meynadier et al. (1994) beyond 5 Ma (Figure 6-9). The agemodel for the ODP Leg 138 record is from the astronomical tuning of the gamma ray attenuation(GRA) density record (Shackleton et al., 1995). The age model for the EPAPIS stack is based onthe correlation of ARM intensity to the oxygen isotope record from ODP Site 1143 from theSouth China Sea (Tian et al., 2002). The age model for Core MD90-0940, from the IndianOcean, was determined by correlation to ODP Sites 709 and 758 using nannofossil events andreversal boundaries.Volume magnetic susceptibility records from the u-channel samples vary between lowpositive and low negative values (Figure 6-10). Triplicate measurements at 1-cm spacing foreach u-channel sample yielded standard deviations that indicate that the low susceptibility valuesare reproducible. The reflectance (L*) and natural gamma radiation records, acquired shipboardeach 5 cm (Expedition 306 Scientists, 2006), co-vary with the susceptibility record (Figure 6-11),

PAGE 142

142indicating that all three parameters are mainly controlled by biogenic (carbonate) dilution ofterrigenous (detrital) input. The susceptibility record can be correlated to the benthic oxygenisotope stack of Lisiecki and Raymo (2004), and this correlation (Figure 6-12) is used to acquirethe age model for the 2.4-5.3 Ma interval at Site U1313. The resulting age model yields a moredetailed picture of sedimentation rates, relative to that acquired from reversal ages and theassumption of constant sedimentation rates in polarity chrons (Figure 6-5). The polarity reversalages in the 2.4-5.3 Ma interval, based on correlations of susceptibility to the benthic isotopestack, are within one obliquity cycle of reversal ages in modern polarity timescales (Table 6-2),with the exception of the reversal boundaries of the Kaena and Mammoth subchrons (values insquare brackets in Table 2) that are up to 155 kyrs younger than given in the Lourens et al.,(2004) timescale. In this interval (2.8-3.4 Ma), a Gaussian-shaped filter centered at 41 kyr,applied to the magnetic susceptibility, can be compared to the astronomic solution for summerinsolation at 65N from Laskar et al. (2004) (Figure 6-13). The filtered susceptibility data showsa modulation that is consistent with the modulation of calculated summer insolation at 65 N.Minor adjustments of the filtered susceptibility record to fit the astronomic solution results inages for the Kaena and Mammoth subchrons that are consistent with published astronomically-based timescales (Table 2).DiscussionThe calibrated polarity reversal ages from Site U1313, based on a correlation of thesusceptibility record to the isotope stack of Lisiecki and Raymo (2004) and to the insolationsolution of Laskar et al. (2004), differ by less than an obliquity cycle (41 kyr) from reversal agesin modern polarity timescales (Table 2). The polarity timescales of Cande and Kent (1995) andLourens et al. (2004) utilized the Gauss-Gilbert timescale of Hilgen (1991a,b) that was based oncyclostratigraphy in the Trubi Limestones in Sicily. Hilgen (1991a,b) correlated the CaCO3

PAGE 143

143cycles in the Trubi Limestones to the precession and eccentricity orbital solutions of Berger(1978). Very minor adjustments to these ages, to make them compatible with the new astronomicsolutions of Laskar et al. (2004), were incorporated in the Lourens et al. (2004) timescale.The relative paleointensity record from IODP Site U1313 can be correlated with thePacific records of Valet and Meynadier (1993) and Yamazaki and Oda (2005), and to the IndianOcean record of Meynadier et al. (1994) (Figure 6-9). The so-called saw-tooth pattern inrelative paleointensity, whereby relative paleointensity declines within polarity chrons andabruptly recovers post-reversal, was first described from ODP Leg 138 sediments (Valet andMeynadier, 1993). This saw-tooth pattern received a great deal of attention as it may provideclues to mechanism of triggering of polarity reversals. The abrupt recovery in paleointensitypost-reversal followed by a slow decrease in intensity leading to the next reversal wasparticularly clear in subchron C2An.1n (late Gauss) in the ODP Leg 138 sediments (Figure 6-9).This saw-tooth pattern has been identified in other equatorial Pacific records, as well as IndianOcean records (Meynadier et al., 1994; Valet et al., 1994; Thibal et al., 1995) but is not seen inall RPI records from this interval (Tauxe and Shackleton, 1994; Kok and Tauxe, 1999). Kok andTauxe (1996a, 1996b) used a cumulative viscous remanence (VRM) model to explain the saw-tooth pattern of paleointensity in the Gauss Chronozone. Individual polarity zones are notuniformly affected by VRM acquisition, and VRM acquired over millions of years can beresistant to the AF demagnetization techniques. Mazaud (1996) developed an alternative modelwhereby some but not all magnetic particles in the sediment acquire NRM at the time ofdeposition, while the remaining grains acquire magnetization after deposition in the subsequentpolarity zone. This leads to a decrease in intensity of the magnetization leading up to a reversal

PAGE 144

144due to the competing effect of the magnetization acquired at the time of deposition and thatacquired progressively in opposite polarity.The RPI record from IODP Site U1313 is one of only a handful of high-sedimentation-rate RPI records for the interval from 2.5 Ma to 5.3 Ma, with sedimentation rates in the 3-6cm/kyr range. From 2.5 Ma to 4 Ma, the RPI record can be correlated to records from the PacificOcean (Valet and Meynadier, 1993; Yamazaki and Oda, 2005). Between 4 Ma and 5.3 Ma, theSite U1313 RPI record is less robust than for the younger part of the record, however, thestandard deviations associated with the mean normalized remanence values are low, indicatingconsistent normalized remanence values for different demagnetization steps. The older part ofthe RPI record can be adequately correlated to the only other RPI record available for this timeinterval, the record of Meynadier et al. (1994) from the Indian Ocean (Figure 6-9). The SiteU1313 RPI record does not clearly show the saw-tooth pattern of RPI variations firstrecognized in the Gauss Chronozone of ODP Leg 138 sediments from the Pacific Ocean (Valetand Meynadier, 1993). This observation tends to indicate that the saw-tooth pattern of RPImay be an artifact of delayed remanence acquisition as suggested by Kok and Tauxe (1996a,b)and Mazaud (1996), rather than a feature of the geomagnetic field at this time.The magnetic stratigraphy from Site U1313 covers the interval from 2.5 Ma to 6.2 Ma, andall known subchrons of the Gauss and Gilbert are recorded. Interestingly, there are no polarityexcursions in the Site U1313 record, although the relatively high sedimentation rates at SiteU1313 might be expected to reveal them, and no excursions have been unequivocally detectedelsewhere in this time interval. Cycles in the magnetic susceptibility record at Site U1313 haveallowed age-calibration by correlation to the benthic oxygen isotope stack of Lisiecki and Raymo(2004). The tuned ages of the reversal boundaries are consistent with current timescales (e.g.

PAGE 145

145Lourens et al., 2004) that all obtained their astronomically calibrated reversal ages for Gauss andGilbert subchrons from the work of Hilgen (1991a,b) in the Trubi Limestones of southern Italy,which is therefore ratified by this present work.

PAGE 146

146Table 6-1. Depth of polarity chrons from IODP Site U1313 in meters composite depth (mcd).Estimated uncertainties in the depth of the reversal boundaries are given inparentheses. ChronCK95 Depth(mcd) Age (ka)CK95 top C2An.1n (base Matuyama) 123.17(.13) 2.5810 base C2An.1n (top Kaena) 142.83(+0.21) 3.0400 top C2An.2n (base Kaena) 146.33(.10) 3.1100 base C2An.2n (top Mammoth) 150.67 (.10) 3.2200 top C2An.3n (base Mammoth) 154.50 (.10) 3.3300 base C2An.3n(base Gauss) 168.61 (.15) 3.5800 top C3n.1n (top Cochiti) 195.28(.10) 4.1800 base C3n.1n (base Cochiti) 200.83(.10) 4.2900 top C3n.2n (top Nunivak) 209.50 (.15) 4.4800 base C3n.2n (base Nunivak) 216.33 (.15) 4.6200 top C3n.3n (top Sidufjall) 224.17 (.10 4.8000 base C3n.3n (base Sidufjall) 228.83 (.15) 4.8900 top C3n.4n (top Thevra) 233.83 (.10) 4.9800 base C3n.4n (base Thevra) 245.67 (.05) 5.2300 top C3An.1n 267.22 (.20) 5.8940 base C3An.1n 277.17(.05) 6.1370 top C3An.2n 280.67(.05) 6.2690

PAGE 147

147Table 6-2. Polarity reversal ages determined at Site U1313, compared with the polarity reversalages in the polarity timescales of Cande and Kent (1995), Lourens et al., (2004) andShackleton et al. (1995). Difference between the Site U1313 reversal ages andtimescale ages are given in parentheses. Ages in square brackets indicate the ages ofreversals in the Gauss Chron based on the fit of susceptibility to the benthic oxygenisotope stack (Figure 6-12), prior to final tuning to the astronomical solution forinsolation (Figure 6-13). Chron U1313Age (Ma) CK95Age (Ma) ATNTSAge (Ma) Leg 138Age (Ma) Base Matuyama 2.616 2.581 (-0.035) 2.581 (-0.035) Top Kaena 3.074 [2.998] 3.040 (-0.034) 3.032 (-0.042) 3.046 (-0.028) Base Kaena 3.153 [3.052] 3.110 (-0.043) 3.116 (-0.037) 3.131 (-0.022) Top Mammoth 3.268 [3.107] 3.220 (-0.048) 3.207 (-0.061) 3.233 (-0.035) Base Mammoth 3.346 [3.176] 3.330 (-0.016) 3.330 (-0.016) 3.331 (-0.015) Base Gauss 3.549 3.580 (+0.031) 3.596 (+0.047) 3.594 (+0.045) Top Cochiti 4.144 4.180 (+0.036) 4.187 (+0.043) 4.199 (+0.055) Base Cochiti 4.277 4.290 (+0.013) 4.300 (+0.023) 4.316 (+0.089) Top Nunivak 4.500 4.480 (-0.02) 4.493 (-0.007) 4.479 (-0.021) Base Nunivak 4.631 4.620 (-0.011) 4.631 (0) 4.623 (-0.008) Top Sidufjall 4.760 4.800 (+0.04) 4.799 (-0.39) 4.781 (+0.021) Base Sidufjall 4.889 4.890 (+0.001) 4.896 (+0.007) 4.878 (-0.011) Top Thevra 5.009 4.980 (-0.029) 4.997 (-0.012) 4.977 (-0.032) Base Thevra 5.273 5.230 (0.043) 5.235 (0.038) 5.232 (-0.041)

PAGE 148

148 Figure 6-1. Location map for IODP Site U1313.

PAGE 149

149 Figure 6-2. Magnetic polarity stratigraphy from IODP Site U1313 in the 120-200 mcd interval.Inclination data from u-channel samples are shown by the blue line. Declination dataare shown by the dotted black line. MAD values are shown by the red line. Left plotshows NRM intensity data on a log scale at 0, 20 and 30 mT AF demagnetizationsteps. Black bars indicate normal polarity, white bars indicate reverse polarity.Chrons are labeled according the Cande and Kent (1992).

PAGE 150

150 Figure 6-3. Magnetic polarity stratigraphy from IODP Site U1313 in the 200-280 mcd intervalfrom u-channel samples using a single AF demagnetization peak field (30 mT).Inclination data (blue line), declination data (dotted black line). Left plot shows NRMintensity data on a log scale prior to AF demagnetization of u-channel samples. Blackbars indicate normal polarity, white bars indicate reverse polarity. Chrons are labeledaccording the Cande and Kent (1992).

PAGE 151

151 Figure 6-4. Vector end-point projections of AF demagnetization data for particular horizons fromu-channel samples. Open circles indicate the vector end-point projection on thevertical plane while closed circles indicate the vector end-point projection on thehorizontal plane.

PAGE 152

152 Figure 6-5. Interval sedimentation rates (black line), and age-depth plot (red line) calculatedusing the magnetic polarity stratigraphy only and interval sedimentation rates fromthe fit of susceptibility to the target benthic oxygen isotope curve (blue line).

PAGE 153

153 Figure 6-6. Gauss Chronozone at Site U1313: Three relative paleointensity proxies: slope ofNRM/ARM (red line), slope of NRM/ARM-acquisition (blue line) and slope ofNRM/IRM (green line) for the 120-170 mcd interval. All calculated in the 20-60 mTpeak field demagnetization interval. Black bar indicates normal polarity, white barreverse polarity. Chrons are labeled according the Cande and Kent (1992). Lower plotshows R-values for the slopes of NRM/ARM, NRM lost versus ARM gained andNRM/IRM.

PAGE 154

154 Figure 6-7. The magnetic grain size proxy, anhysteretic susceptibility divided by susceptibility(karm/k), for the 2.5-3.3 Ma interval. Shading shows the darker (glacial) intervalscharacterized by coarser magnetite grain size.

PAGE 155

155 Figure 6-8. Later part of the Gilbert Chronozone at Site U1313: Two relative paleointensityproxies NRM/ARM (red line) and NRM/IRM (green line) with standard deviationshown by a black bar, for the 170-220 mcd interval, calculated over five AFdemagnetization steps in the 20-30 mT peak field interval. Black indicates normalpolarity, white reverse polarity. Chrons are labeled according the Cande and Kent(1992).

PAGE 156

156 Figure 6-9. Relative paleointensity records from IODP Site U1313 (black line), the Pacificrecord of Valet and Meynadier (1993) (blue line), the Pacific EPAPIS stack(Yamazaki and Oda, 2005) (green line) and the Indian Ocean record (red line)(Meynadier et al., 1994) (between 2.5-4 Ma. Black bar indicates normal polarity,white bar reverse polarity. Chrons are labeled according the Cande and Kent (1992).Lower plot shows the IODP Site U1313 relative paleointensity record after a 9-pointsmooth (blue line) overlaid by the Indian Ocean paleointensity record (Meynadier etal., 1994) (red line) in the 3.5-5.2 Ma interval.

PAGE 157

157 Figure 6-10. Volume magnetic susceptibility from u-channel samples. Black line is a mean ofthree measurements, red bars indicate the standard deviation from the mean.

PAGE 158

158 Figure 6-11. Volume magnetic susceptibility from u-channel samples (blue line) and L*reflectance data measured shipboard (black line). Red line is smoothed naturalgamma radiation (NGR) data.

PAGE 159

159 Figure 6-12. Mean volume magnetic susceptibility (black line) tuned to the benthic oxygenisotope stack of Lisiecki and Raymo (2004) (red line) for the 2.5-5.3 Ma interval.

PAGE 160

160 Figure 6-13. Output of a gaussian filter centered on a period of 41 kyr (bandpass= 0.024 kyr-1)applied to the u-channel volume susceptibility record (black line) and the astronomicsolution for summer insolation at 65N from Laskar et al. (2004).

PAGE 161

161CHAPTER 7ODP SITE 1092 REVISED COMPOSITE DEPTH SECTION HAS IMPLICATIONS FORUPPER MIOCENE "CRYPTOCHRONS"IntroductionODP Site 1092 is located in the sub-Antarctic South Atlantic (46.7S, 7.8E, waterdepth= 1974m). A magnetic polarity stratigraphy was presented for two time intervals (1.95 to~3.6 Ma and ~5.9 to ~13.5 Ma) by Evans and Channell (2003). As is routine aboard the R/VJoides Resolution, composite stratigraphic depths (mcd) for site 1092 were constructed frommulti-sensor track (MST) data. Magnetic susceptibility, gamma ray attenuation porosity(GRAPE) and light reflectance data, were used to correlate among holes at the site and to derivean optimal record (splice) of the sedimentary section (Shipboard Scientific Party, 1999). Thecomposite depths for ODP site 1092 have now been revised using X-ray fluorescence (XRF)scans of half-cores. These new data have allowed improved correlation among the holes at thesite. The revised meters composite depth (rmcd) scheme has resulted in significant changes inhole-to-hole correlation, particularly within the interval correlative to subchron C5n.2n.Using the shipboard composite section, Evans and Channell (2003) identified four reversepolarity subzones within the polarity zone correlative to C5n.2n. The four polarity subzones wereconsidered to be correlative to "cryptochrons'' in the polarity timescale of Cande and Kent (1992)and were labeled as C5n.2n-1 to C5n.2n-4. The results imply that "cryptochrons" originallyidentified within marine magnetic anomaly 5 by Blakely (1974) signify polarity reversals ratherthan solely geomagnetic intensity minima. On the revised composite depth scale, the reversepolarity subchrons labeled as C5n.2n-2 and C5n.2n-3 by Evans and Channell (2003) become asingle subchron recorded in two different holes. The result supports the revised composite depthscale and indicates three, not four, subchrons within C5n.2n.

PAGE 162

162Revised Composite Depths (rmcd)Shipboard MST data (magnetic susceptibility, GRAPE) and light reflectance data from site1092 are often too uniform, particularly in the Upper Miocene section (120-185 mcd), for precisehole-to-hole correlation. As part of a project to assess carbonate sedimentation in the southernoceans, Westerhold and Bickert (in preparation) have measured most of the archive halves ofcores from site 1092 using the XRF core scanner at the Universitt Bremen (Rhl and Abrams,2000). Fe and Ca intensity data, measured every 2 cm, are often more variable than shipboardMST data and generally provide an efficient means of hole-to-hole correlation.Some core sections within the shipboard composite splice were not scanned for XRFbecause the working and archive halves had been too heavily sampled (partly for u-channels togenerate the magnetic data). For core sections without XRF data, shipboard magneticsusceptibility could be adequately matched to core sections with Fe intensity data from XRFscans. Some cores from outside the splice had to be stretched or squeezed to conform with theoverall depth scale of the shipboard composite section. Drilling related expansion andcontraction in these poorly consolidated sediments contributes to the lack of precise correlationof depth scales between holes (Shipboard Scientific Party, 1999). The depth scale of theshipboard composite section (with no stretching or squeezing of cores within the splice) wasadhered to in the construction of the revised composite section (rmcd).Above core 1092A-12H, the shipboard composite section (mcd) is consistent with hole-to-hole correlations based on both MST and XRF data. In the shipboard splice, core 1092C-12Hoverlies 1092A-12H. core 1092C-12H can be well correlated to 1092B-12H using XRF andmagnetic susceptibility, and this correlation is consistent with shipboard composite depths.Correlation from 1092C-12H to the underlying core in the splice (1092A-12H) is poor for bothMST and XRF data. However, 1092B-12H can be well correlated to 1092C-13H, but only when

PAGE 163

163the latter is moved 90 cm up relative to 1092B-12H. This shift is the uppermost modification ofthe composite section depths. Below this, 1092A-13H can be well correlated to its neighboringcores in the splice (1092C-13H and 1092C-14H), however, the correlation to 1092C-14Hrequires that this core should be moved up 2.58 m into 1092A-13H. The rationale for thisadjustment, based on Fe intensity (XRF) data, is illustrated in Figure 7-1.Implications for Magnetic StratigraphyAugmentation of the MST data by XRF data leads to offsets between the shipboardcomposite depths (mcd) and the revised composite depths (rmcd) that reach a maximum of 3.54m in 1092C-14H (Table 5-1). The resulting modification of the composite section provides newcomposite depths for polarity zone boundaries at site 1092 (Table 7-2 and Figure 7-2), with newage estimates for subchrons not included in the standard geomagnetic polarity timescale (GPTS).The magnetostratigraphic interpretation (the correlation of polarity zones to polarity chrons) isthe same as in Evans and Channell (2003) apart from the interval within C5n.2n. When utilizingthe shipboard composite section, this normal polarity chronozone appeared to contain four thinpolarity subzones that Evans and Channell (2003) associated with cryptochrons in marineoceanic magnetic anomaly data. The revision of the composite section indicates that there isduplication of polarity subzones that is an artifact of miscalculations in shipboard compositedepths. Polarity subchrons, that were originally labeled C5n.2n-2 (recorded in core 1092A-13H)and C5n.2n-3 (recorded in core 1092C-14H), become a single subchron (relabeled as C5n.2n-2).The realignment of cores 1092A-13H and 1092C-14H within the composite section (Figure 7-1b) results in coincidence of the records of C5n.2n-2 and C5n.2n-3 (Figure 7-3a,b). This notonly ratifies the adjustment of the composite section but also reduces the number of subchronswithin C5n.2n from four to three (Figure 7-3), consistent with the number of cryptochrons inthe GPTS of Cande and Kent (1992). Normalized remanence (mean NRM/IRM), used as a

PAGE 164

164proxy for geomagnetic paleointensity in Evans and Channell (2003), can also be well correlatedbetween cores 1092A-13H and 1092C-14H after revision of the composite depths (Figure 7-3c,d). The revised composite depths also alter the estimated duration of C5n.2n-2 and C5n.2n-3.C5n.2n-2 now has an estimated duration of 5 kyr, while the duration of C5n.2n-3 increases to 11kyr, assuming a uniform sedimentation rate within C5n.2n.In the Orera section (Spain), Abdul Aziz et al. (2003) found three normal polarity subzoneswithin C5r (two within C5r.2r and one within C5r.3r) that are not represented in the GPTS ofCande and Kent (1992, 1995). This augmented C5r could be correlated with the polarity zonesat site 1092 by moving the onset of C5r.3r to 179.41 rmcd (Krijgsman, pers comm., 2003). Thepolarity zones at site 1092 correlative to these three features have thicknesses of 1.75m (C5r.2r-1n), 0.23m (C5r.2r-2n) and 0.38m (C5r.3r-1n). This interpretation appears consistent with ahiatus at 180.48 rmcd advocated by Censarek and Gersonde (2002) from the diatombiostratigraphy. The hiatus was placed at 180.48 rmcd on the basis of the coincidence of the firstoccurrences of Denticulopsis praedimorpha and Nitzschia denticuloides, and the last occurrenceof Actinocyclus ingens var. nodus, although the ages of these diatom events are poorlyconstrained.In a recent study of chron C5 at ODP site 887, Bowles et al. (2003) found no evidence forreverse polarity subzones within C5n.2n and concluded that cryptochrons of this agerecognized in marine magnetic anomaly data represent fluctuations in geomagnetic fieldintensity. The mean sedimentation rate in C5n.2n at site 887 is 1cm/kyr, or ~ 30% of that at site1092, and it is therefore less likely that polarity intervals of the duration seen at ODP site 1092would have been recorded at site 887.

PAGE 165

165The short duration of the reverse polarity intervals within C5n.2n at site 1092 may indicatethat they are excursions rather than polarity subchrons. Various criteria have been suggested todistinguish excursions from polarity subchrons (Cande and Kent, 1992; Gubbins, 1999;Roberts and Lewin-Harris, 2000). Roberts and Lewin-Harris (2000) suggested that for a polarityexcursion to qualify as a polarity subchron it should be bounded by two field reversals, and thatdecreases in paleointensity should be apparent at both bounding reversals. Of the three subchronswithin C5n.2n at site 1092, only C5n.2n-3 exhibits a clear recovery in paleointensity between thereversals.The fundamental conclusion of Evans and Channell (2003) that short duration (5-11 kyr)polarity subchrons exist within C5n.2n, that are probably correlative to cryptochronsinterpreted from oceanic magnetic anomaly data, has not changed. However, the number ofpolarity subchrons within C5n.2n has been reduced from four to three by revision of compositedepths at site 1092.

PAGE 166

166Table 7-1. Adjusted depths of core tops from ODP site 1092. Core mbsf Ship mcd* Offsetmcd tombsf(m) Revisedmcd (rmcd) Offsetmbsf tormcd(m) Offset mcdto rmcd (m) 177-1092A12H 103 115.41 12.41 114.48 11.48 -0.93 13H 112.5 126.72 14.22 125.80 13.30 -0.92 14H 122 138.12 16.12 136.51 14.51 -1.61 15H 131.5 149.74 18.24 147.26 15.76 -2.48 16H 141 160.18 19.18 159.01 18.01 -1.17 17H 150.5 168.72 18.22 170.14 19.64 1.42 18H 160 179.85 19.85 181.57 21.57 1.72 19H 169.5 191.84 22.34 191.07 21.57 -0.77 20H 179 201.34 22.34 200.57 21.57 -0.77 177-1092B13H 111.4 122.22 10.82 121.57 10.17 -0.65 14H 121.4 134.32 12.92 132.68 11.28 -1.64 15H 130.9 146.62 15.72 144.14 13.24 -2.48 16H 140.4 155.72 15.32 154.74 14.34 -0.98 17H 149.9 166.76 16.86 165.23 15.33 -1.53 18H 159.4 175.31 15.91 176.96 17.56 1.65 177-1092C13H 108.5 119.93 11.43 119.01 10.51 -0.92 14H 118 132.82 14.82 129.28 11.28 -3.54 15H 127.5 142.70 15.20 140.22 12.72 -2.48 16H 137 155.70 18.70 151.72 14.72 -3.98 17H 146.5 166.38 19.88 162.34 15.84 -4.04 18H 156 175.79 19.79 173.91 17.91 -1.88

PAGE 167

167Table 7-2. Position of the polarity zone boundaries at site 1092 in shipboard mcd and rmcd. Agesof polarity chrons are from the geomagnetic polarity timescale (GPTS) of Cande andKent (1992, 1995). Ages of polarity subchrons not featured in the GPTS are markedby an asterisk and estimated assuming constant sedimentation rates within polaritychrons. Depth(mcd) rmcd Chron Age (Ma)CK95 121.48 120.55 Base C5n.1n 9.880 122.40 121.47 Top C5n.2n 9.920 127.92 127.00 Top C5n.2n.1 10.098* 128.01 127.15 Base C5n.2n.1 10.103* 132.88 131.95 Top C5n.2n.2 10.258* 133.02 132.16 Base C5n.2n.2 10.263* 151.31 148.60 Top C5n.2n.3 10.803* 151.43 148.95 Base C5n.2n.3 10.814* 156.60 154.12 Base C5n.2n 10.949 158.80 157.82 Top C5r.1n 11.052 160.00 159.02 Base C5r.1n 11.099 163.10 161.91 Top C5r.2n 11.476 164.54 163.37 Base C5r.2n 11.531 170.60 169.07 Top C5r.3r.1n 11.866* 170.79 169.26 Base C5r.3r.1n 11.877* 171.75 173.24 Top C5An.1n 11.935 173.00 174.42 Base C5An.1n 12.078 174.20 175.67 Top C5An.2n 12.184 174.49 175.94 Base C5An.2n 12.401 177.70 179.35 Top C5Ar.1n 12.678 178.50 180.15 Base C5Ar.1n 12.708 179.00 180.65 Top C5Ar.2n 12.775 179.42 181.13 Base C5Ar.2n 12.819 180.29 181.94 Top C5AAn 12.991 181.55 183.20 Base C5AAn 13.139 181.95 183.60 Top C5AAr.1n 13.208* 182.02 183.67 Base C5AAr.1n 13.220* 182.50 184.15 Top C5ABn 13.302

PAGE 168

168 Figure 7-1. (a) Fe intensity (XRF) data plotted as a five-point moving average on the shipboardcomposite depth (mcd) scheme, with the position of the three subchrons identified incore sections 1092C-13H-6, 1092A-13H-4 and 1092C-14H-2 (C5n.2n-1 to 3) byEvans and Channell (2003). The thick line indicates data from hole 1092A, the thinline from hole 1092B and the dashed line from hole 1092C. (b) Fe intensity (XRF)data plotted as a five-point moving average on the revised composite depth (rmcd)scheme. Line notation as for Fig. 1a. On the revised composite depth (rmcd) scheme,C5n.2n-2 and C5n.2n-3 merge into a single subchron (C5n.2n-2).

PAGE 169

169 Figure 7-2. Inclination of the characteristic magnetization component plotted against revisedcomposite depth (rmcd) for site 1092. Polarity chrons are labeled according to Candeand Kent (1992). Arrows indicate subchrons within C5n.2n, C5r.3r and C5AAr.1n.Polarity interpretation: black indicates normal polarity, white reverse polarity.

PAGE 170

170 Figure 7-3. Site 1092: (a) Inclination of the characteristic magnetization component plottedagainst shipboard composite depth (mcd) showing C5n.2n-2 and C5n.2n-3 accordingto Evans and Channell (2003). (b) Inclination of the characteristic magnetizationcomponent plotted against revised composite depth (rmcd) showing that subchronsC5n.2n-2 and C5n.2n-3 of Evans and Channell (2003) become a single subchron(now labeled C5n.2n-2). (c) Mean of the ratio of natural remanent magnetization(NRM) to isothermal remanent magnetization (IRM), calculated for ninedemagnetization steps in the 20-60 mT demagnetization range, plotted againstshipboard composite depth (mcd), (d) Mean of the ratio of natural remanentmagnetization (NRM) to isothermal remanent magnetization (IRM), calculated fornine demagnetization steps in the 20-60 mT demagnetization range, plotted againstrevised composite depth (rmcd).

PAGE 171

171CHAPTER 8ASTRONOMICAL AGES FOR MIOCENE POLARITY CHRONS C4AR-C5R (9.3-11.2 MA),AND FOR THREE EXCURSION CHRONS WITHIN C5N.2NIntroductionSite 1092 was drilled in January 1998 on Meteor Rise, close to DSDP Site 704, duringODP Leg 177 in the South Atlantic. The site produced a clear magnetic stratigraphy from 4-13Ma including the interval between C4Ar.1n and C5r.1n when sedimentation rates were ~3cm/kyr (Figure 8-1). Four short reverse polarity intervals (excursion chrons) were identifiedwithin subchron C5n.2n (Evans and Channell, 2003). This number was reduced to three due torecognition of an error in the Site 1092 composite splice, revealed by correlation of X-rayfluorescence (XRF) core scanning data, that resulted in duplication of one of the excursion zones(Evans et al., 2004).The three "cryptochrons" in C5n.2n listed by Cande and Kent (1992, 1995), hereafterreferred to as CK92/95, originate from the work of Blakely (1974) who identified three short-wavelength magnetic anomalies (tiny wiggles in the terminology of CK92/95) withinAnomaly 5 from a stack of marine magnetic anomaly (MMA) records from the NE PacificOcean. The term cryptochron expresses the uncertainty in origin of these tiny wiggles thatmay be attributed to polarity excursions/chrons or fluctuations in geomagnetic paleointensity.The resolution of Blakelys (1974) record did not allow precise estimation of the spacing of theshort wavelength anomalies. They were placed at ~300 kyr intervals within C5n.2n, and Blakely(1974) attributed these short wavelength anomalies to full polarity reversals of the geomagneticfield. These polarity subchrons within C5n.2n were included in some subsequent timescalesincluding those of Ness et al. (1980) and Harland et al. (1982, 1990), but were relegated tocryptochrons in CK92/95.

PAGE 172

172In the last decade, CK92/95 has been the standard polarity timescale used in the vastmajority of studies that involve the integration of magnetic, bioand chemostratigraphies. Thetimescale was constructed by deriving a composite geomagnetic polarity sequence from marinemagnetic anomaly spacings. In the 0-5 Ma interval, CK95 used astrochronologically-derivednumerical ages for polarity chrons available at the time (Shackleton et al., 1990; Hilgen et al.,1991). Beyond 5 Ma, using the assumption of smoothly varying spreading rates, a splinefunction was used to fit 8 radiometric age-calibration points, in the 14.8-84.0 Ma interval, to theLate Cretaceous-Cenozoic polarity record.Since the publication of CK92/95, the astrochronological calibration of the polaritytimescale has been extended beyond the last 5 Myrs. The majority of these developments havebeen incorporated into the recently published ATNTS2004 timescale of Lourens et al. (2004).For the Late Miocene, these authors used a blend of previously published astronomicaltimescales (Abdul Aziz et al., 2003; Hilgen et al., 1995; 2003). adjusted to the latest astronomicalsolutions (Laskar et al., 1993). This adjustment resulted in minor modification of the ages of thereversal boundaries from those given in the primary publications.For the polarity chrons in the C4Ar.1r -C4Ar.3r interval, Lourens et al., (2004) utilizedrecords from the Mediterranean (Hilgen et al., 1995), and from Monti dei Corvi (northern Italy)(Hilgen et al., 2003). At Monti dei Corvi, Hilgen et al. (2003) tuned a cyclic alternation of marls,marly limestones and organic-rich beds to the 65N summer insolation time series (Laskar et al.,1993). This allowed astronomic calibration of the polarity chrons in the interval from C4An tothe young end of C5n.2n. In the C5n.2n-C5Ar interval, Lourens et al. (2004) incorporated thework of Abdul Aziz et al. (2003) from the lacustrine Orera section in Spain. This sectionproduced a reliable magnetic stratigraphy from the onset of C5n.2n to C5Ar.2n. The astronomic

PAGE 173

173calibration of the reversal boundaries was accomplished using the cyclic alternation ofmudstones and dolomitic carbonates identified in the sequence.In this study, we use new oxygen isotope records from ODP Site 1092 (Paulsen et al., inpress) to astronomically calibrate polarity chrons C4Ar-C5r (9.3-11.2 Ma). Spectral analysisreveals a dominant obliquity (41-kyr) cycle in the oxygen isotope record and we use this tocalibrate the Site 1092 record to the astronomical solution (Laskar et al., 2004). This studydiffers from previous astronomical timescales for this interval (Abdul Aziz et al., 2003; Hilgen etal., 2003) in that it uses oxygen isotope records rather than lithologic cycles as the means ofastronomical calibration.Methods and ResultsAt ODP Site 1092, oxygen isotope data for the Middle to Late Miocene (7-15 Ma) weregenerated from three species of foraminifers (Figure 8-2) (see (Paulsen et al., in press). Benthicoxygen isotope data were generated from the benthic foraminifer Cibicidoides kullenbergi.Planktic oxygen isotope data were generated from two species: Globigerina bulloides andGloborotalia scitula. A power spectrum using the Blackman-Tuckey method with a Bartlettwindow, was generated in the depth domain from the stacked oxygen isotope record, using theAnalyseries program of Paillard et al. (1996) (Figure 8-3a). This showed power at twofrequencies: 0.78 m-1 and 0.25 m-1. A gaussian filter centered at 0.78 ( 0.234) m-1 was thenapplied to the stacked oxygen isotope records to extract this dominant cycle. The record was thenplaced on an initial age model based on the magnetic stratigraphy (Evans and Channell, 2003)and the ATNTS2004 timescale (Lourens et al., 2004). The dominant cycle was identified as the41-kyr obliquity cycle (Figure 8-3b) and individual (obliquity) cycles were numbered fromyoungest to oldest (1-45) (Figure 8-2). The second peak at a frequency of 0.25 m-1 was identifiedas close to the 100 kyr eccentricity period.

PAGE 174

174The oxygen isotope stack was tuned to an astronomical target curve, which was derivedfrom the sum of normalized values (minus the mean and divided by the standard deviation) ofeccentricity (E), obliquity (T) and negative precession (P) (E+T-P) (Laskar et al., 2004). Tuningof the isotope record was only possible in the 9.3-11.2 Ma interval due to lower sedimentationrates and condensed horizons outside this interval.For Neogene sections, it is often assumed that the 41 kyr component of "18O is globallycorrelative, and not likely to be variable in phase relative to orbital forcing (Clemens, 1999).Much of the power in the climate spectrum since the early Oligocene appears to be concentratedin the obliquity band (Zachos et al., 2001). At Site 1092, the final age model was obtained bytuning the initial age model (from ETP tuning) until the coherence calculated using cross-spectral analysis was maximized between the filtered "18O record (filter centered at 41 kyr) andthe orbital obliquity signal. Coherence between the oxygen isotope stack and ETP is close to oneat the obliquity frequency (Figure 8-3c). The 1.2 Myr modulation of the obliquity cycle is clearlyvisible in the filtered isotope record (Figure 8-4) facilitating an unambiguous match to the orbitalobliquity target. In this way, we produced an orbitally tuned age model for the 9.3-11.2 Mainterval at Site 1092.The resulting astronomically tuned ages for C5n.2n are 44 kyrs younger at the onset, and19 kyrs younger at the termination, than ages in ATNTS2004 (Lourens et al., 2004). The newages are also significantly different from the CK92/95 ages, with the onset of C5n.2n being 47kyrs older and the termination 62 kyrs older (Table 8-1). Although the difference is close to oneobliquity cycle, an offset by one obliquity cycle would give an inappropriate match between the"18O records and the ETP curve (Figure 8-4). For example, if we shift the oxygen isotope recordsone obliquity cycle younger then the light "18O values of G. bulloides and C. kullenbergi in the

PAGE 175

175interval 10.78 to 10.72 Ma (Figure 8-4) would be located in the ETP minimum at ~10.7 Mawhich can be considered unrealistic. Interval sedimentation rates at Site 1092, calculated for theC4Ar-C5r interval using the age-depth tie points from the tuning of the oxygen isotope records,vary from 1.7 cm/kyr to 3.7 cm/kyr for the entire interval and vary from 2.5 cm/kyr to 3.7 cm/kyrfor C5n.2n (Figure 8-5).Comparison with Other TimescalesThe greatest potential source of error in the age model is uncertainty in the orbital solution,which may be as high as 20 kyr at 10 Ma (Lourens et al., 2004; Laskar et al., 2004), whereas ourtuning errors should be no more than a few thousand years. A component of the uncertainty inplacement of the reversal boundaries can be estimated using the mean sedimentation rate (3cm/kyr) and the response function width (at half-height) of ~4.5 cm for the 2G Enterprises u-channel magnetometer, giving a nominal error of ~2 kyrs for each reversal boundary. This errorwas mitigated by deconvolution (Guyodo et al., 2002) of the u-channel record across theexcursional intervals (Evans and Channell, 2003), resulting in a modified error estimate of ~1kyr for the C5n.2n polarity excursions. These estimates do not include error in placement ofpolarity zone boundaries associated with delayed remanence acquisition, referred to as post-Depositional Remanent Magnetization (pDRM). Following Channell and Guyodo, (2004), thesediment lock-in beneath the bioturbated surface layer in pelagic sediments is abrupt, and cantherefore the lock-in depth can be estimated from the mean sedimentation rate and the thicknessof the surface bioturbated mixed layer (<10 cm in most pelagic environments (Trauth et al.,1997; Smith and Rabouille, 2002)). In the case of Site 1092, assuming a 10 cm bioturbatedsurface layer, the delay in remanence acquisition would be about 3 kyr.A data gap occurs in the oxygen isotope records at 155.8-157.3 revised meters compositedepth (rmcd). The gaussian filter identifies two obliquity cycles in this data gap (Figure 8-2). If

PAGE 176

176we assume that three cycles occurred in this gap, the sedimentation rates would be anomalouslylow (2.3 cm/kyr), while a single cycle causes an increase in sedimentation rates (5.1 cm/kyr).Two obliquity cycles yields sedimentation rates of 3.2 cm/kyr consistent with those adjacent tothis interval. The revised composite section is well constrained in this interval (Evans et al.,2004), and there are no indications in physical properties of a likely change in sedimentationrate.Comparison of the new astronomically-tuned ages for subchrons C4Ar.1n to C5r.1n (9.3-11.2 Ma) with ATNTS2004 (Lourens et al., 2004) reveal differences of 5-48 kyrs (Table 8-1). Alarge part of the age discrepancy is probably due to the low resolution of the paleomagneticrecord in the Monti de Corvi section (Hilgen et al., 2003) that provides the basis for theATNTS2004 timescale in this interval. In this section, the polarity reversals are poorly definedand the pattern fit of polarity zones to polarity chrons is ambiguous, due to weak and unstablemagnetic remanence. Hilgen et al. (2003) gave errors of 25-77 kyrs for the astronomical ages forthe reversal boundaries at Monti dei Corvi, due largely to poor definition of polarity zones (seeTable 3 of Hilgen et al., 2003). For C4Ar.1n-C4Ar.2n, the differences between the astronomicalages obtained at Site 1092 and those obtained at Monti dei Corvi are within these error estimates,and the differences reach 71 kyrs for subchron C5n.1n where the error estimates at Monti deiCorvi are largest.Site 1092 and CK92/95 ages differ by ~100 kyrs in the interval between C4Ar.1n andC4Ar.2n. Between the top of chron C5n.1n and the base of C5r.1n, the differences are 44-67 kyrs(Table 6-1). This narrow range indicates that the durations of subchrons in this interval are veryconsistent between the two timescales. CK92/95 relies on two calibration points for the middle tolate Miocene interval. The first is placed at the older end of subchron C3n.4n with an age of 5.23

PAGE 177

177Ma from the astrochronological work of Hilgen (1991). The second age calibration point at 14.8Ma at the young end of subchron C5Bn, was derived from radioisotopic age constraints on thecorrelative N9/N10 foraminifer zone boundary (see Cande and Kent, 1992).Shackleton et al. (1995) constructed a timescale for the Late Neogene based on gamma rayattenuation (GRA) bulk density data from sediment cores obtained during ODP Leg 138. For the0-6 Ma interval, cycles identified in the GRA bulk density data were tuned to the orbitalinsolation record of Berger and Loutre (1991). The Late Miocene (6-14.8 Ma) timescale wasrecalibrated using two tie-points at 5.875 Ma (termination of C3An) and 9.64 Ma (termination ofC5n) and fitting a cubic-spline to estimate spreading rates in the manner adopted by CK92. Theage control point at the termination of C5n (9.64 Ma) was generated by taking the radiometricage of 9.66 +/-0.05 Ma from Baksi (1992) and adjusting it to the closest age that allowed theGRA bulk density to be matched directly to the insolation record. The ages obtained byShackleton et al. (1995) are 153-225 kyrs younger than those obtained for Site 1092 (Table 8-1).There are several possible factors that could contribute to these differences. (1) The sedimentrecord from the ODP Leg 138 sites may not be complete in the older part, possibly attributable touse of the XCB coring system. (2) The quality of the GRA bulk density data deteriorates, and thematch to the insolation record becomes ambiguous, in the older part of the record. (3)Sedimentation rates are low (~1-2 cm/kyr) in the Late Miocene at Leg 138 sites (Shackleton etal., 1995).The Monti Gibliscemi section in Sicily (Italy) is a deep marine cyclically beddedhemipelagic succession of Miocene age (Hilgen et al., 2000). Due to weak magnetic intensitiesand overprinting, a magnetic stratigraphy was not obtained from the section. Hilgen et al. (2000)]indirectly estimated astronomical ages for polarity chron boundaries by transferring the

PAGE 178

178astronomical ages of calcareous nannofossil events at Monti Gibliscemi to ODP Leg 138 sites inthe equatorial Pacific that have reliable magnetic stratigraphies (Schneider, 1995). Linearinterpolation of sedimentation rates between nannofossil datums yielded ages for polarity chronboundaries (Hilgen et al., 2000). In the interval from C5n.1n to the base of C5n.2n, the ages fromMonti Gibliscemi are consistently older than ages from Site 1092 with the mean difference being~40 kyrs (Table 8-1). For subchron C5r.1n, the ages are younger than those obtained in thisstudy by 37 and 38 kyrs at the young and old end of the subchron, respectively.Excursion ChronsPrevious estimates of the duration of the polarity excursion chrons within C5n.2n fromODP Site 1092 have relied on the assumption of constant sedimentation rates within the chron(Evans and Channell, 2003). Based on a mean sedimentation rate within C5n.2n of ~3 cm/kyr,the excursion chrons were estimated to have a duration of 6-11 kyrs. The new astronomicalcalibration yields durations for these excursion chrons of 3-4 kyrs (Table 8-1).DSDP Site 608 has recently yielded a revised magnetic stratigraphy for the Middle to LateMiocene (Krijgsman and Kent, 2004). Discrete samples collected every 2.5 cm at Site 608indicate three excursions within C5n.2n, albeit represented by single samples, with estimateddurations of 1-6 kyrs. Three reverse polarity intervals at ODP Site 884 on the Detroit Seamountin the NW Pacific Ocean were placed within C5n.2n (Roberts and Lewin-Harris, 2000), andwere calculated by the authors to have durations of 6, 26 and 28 kyrs. Ambiguities in theinterpretation of the magnetic stratigraphy at Site 884, and the apparent duration of these reversepolarity intervals, makes it unlikely that they correlate to the excursional directions identified atSite 1092 (see Evans and Channell, 2003).Roperch et al. (1999) studied a 4.5 km thick middle Miocene continental red bed section inthe Bolivian Altiplano. Magnetostratigraphic results indicate that the sequence was deposited

PAGE 179

179during the 14-9 Ma interval, and has a mean sedimentation rate of 97 cm/kyr in the 11.5-9.2 Mainterval. Roperch et al. (1999) identified one reverse polarity interval represented by fivesamples (at 3714-3719 m above base of section) within the normal polarity interval correlative toC5n.2n. Using an estimate for the mean sedimentation rate within C5n.2n (97 cm/kyr), thisreverse interval has a duration of ~5 kyrs. The Ulloma tuff lies ~100 meters below the reversepolarity zone and has yielded an age of 10.35 +/-0.06 Ma from 40Ar/39Ar dating of sanidinecrystals (Marshall et al., 1992). Assuming a constant sedimentation rate from the top of thepolarity zone correlative to C5n.2n to the Ulloma tuff the reverse polarity zone has an age of10.21 Ma and a duration of ~8 kyrs.Bowles et al. (2003) studied the sedimentary section at ODP Site 887 from the NorthPacific that covers the C5n interval. The core was sampled using discrete samples at 2.5 cmspacing. The mean sedimentation rate within C5n.2n (1 cm/kyr) implies a sampling resolution of2500 yrs, however no reverse polarity intervals were detected within C5n.2n. In view of thesedimentation rates at Site 887, it is possible that polarity intervals of the duration seen at ODPSite 1092 would not have been recorded using this sampling regime.The Bowers et al. (2001) deep-tow marine magnetic anomaly (MMA) record from thesouthern East Pacific Rise (EPR) (Figure 8-7) is one of the most detailed MMA records for thistime interval with an the average half-spreading rates of 42 mm/yr. In Figure 8-7, we correlatethe Site 1092 paleointensity record from Evans and Channell (2003) to the deep-tow MMArecord. The three brief excursion chrons observed in C5n.2n at Site 1092 can then be placed intothe deep-tow MMA record (arrows from below in Figure 8-7). The preferred correlationbetween the relative paleointensity record from Site 1092 and the deep tow magnetic anomalyrecord yields a correlation of Site 1092 excursion chrons to the deep-tow record that differs from

PAGE 180

180the Bowers et al. (2001) correlation (arrows from top in Figure 8-7) of CK92/95 tiny wiggles(cryptochrons) from the North Pacific stack to the EPR deep-tow record.Oxygen isotope records from ODP Site 1092 have allowed astronomic calibration of theages of eight polarity chron boundaries (C4Ar.1n-C5r.1n), and of three excursion chrons withinC5n.2n (Evans and Channell, 2003; Evans et al., 2004). This is the first time astronomicallycalibrated ages have been assigned to the excursion chrons within C5n.2n, and they indicatedurations of 3-4 kyr. This duration estimate is consistent with the model of Gubbins (1999) thatpredicts that excursions should have durations less than the magnetic diffusion time (3 kyrs) forthe inner core (Hollerbach and Jones, 1995). The duration of these excursions is less than theduration for reversal transitions such as the Matuyama-Brunhes boundary (5-10 kyrs, e.g.Channell and Kleiven, 2000) implying that the outer core must maintain the opposite ortransitional polarity state for greater than ~3 kyrs to allow the outer core field to diffuse throughthe inner core and hence stabilize the outer core field (Gubbins, 1999). The duration forexcursions, such as those within C5n.2n, which appear as abrupt swings to reverse polarity andreturn to normal polarity, was apparently insufficient for establishment of a prolonged reversepolarity interval.

PAGE 181

181Table 8-1. Astronomical ages from recent timescales compared with those inferred at ODP Site1092. Numbers in parentheses indicate the difference between Site 1092 estimates(this paper) and other timescales. CK95Cande and Kent (1995), ATNTS2004-Lourens et al., (2004), A2003Abdul Aziz et al. (2003), S1995Shackleton et al.(1995), H1995Hilgen et al. (1995), H2000Hilgen et al. (2000), H2003Hilgen etal. (2003). Subchron Depth (rmcd) 1092 age (ka)(errors) CK95 age (ka) ATNTS2004(ka) A2003 (ka) S1995 (ka) H1995(ka) H2000 (ka) H2003 (ka) Top C4Ar.1n 105.13 (.03) 9351 () 9230 (-121) 9312 (-39) 9142 (-209) 9364 (+13) Base C4Ar.1n 106.96 (.19) 9443 () 9308 (-135) 9409 (-34) 9218 (-225) 9428 (-15) Top C4Ar.2n 112.60 (.05) 9671 () 9580 (-91) 9656 (-15) 9482 (-189) 9629 (-42) 9652 (-19) 9687 (+16) Base C4Ar.2n 115.60 (.04) 9765 () 9642 (-123) 9717 (-48) 9543 (-222) 9740 (-25) 9762 (-3) 9729 (-36) Top C5n.1n 116.80 (.05) 9807 () 9740 (-67) 9779 (-28) 9639 (-168) 9841 (+34) 9770 (-37) Base C5n.1n 120.79 (.05) 9942 () 9880 (-62) 9934 (-8) 9775 (-167) 10000 (+58) 9871 (-71) Top C5n.2n 121.61 (.07) 9968 () 9920 (-62) 9987 (+19) 9815 (-153) 10037 (+66) 10004 (+36) Top C5n.2n.1 127.00 10154 () 10091 (-63) Base C5n.2n.1 127.09 10157 () 10093 (-64) Top C5n.2n.2 131.96 10309 () 10248 (-61) Base C5n.2n.2 132.10 10313 () 10252 (-61) Top C5n.2n.3 148.83 10826 () 10782 (-44) Base C5n.2n.3 148.95 10829 () 10785 (-44) Base C5n.2n 154.12 (.09) 10996 () 10949 (-47) 11040 (+44) 11043 (+47) 10839 (-157) 10998 (+2) Top C5r.1n 157.71 (.12) 11108 () 11052 (-57) 11118 (+10) 11122 (+14) 10943 (-165) 11071 (-37) Base C5r.1n 159.03 (.03) 11149 () 11099 (-50) 11154 (+5) 11158 (+9) 10991 (-158) 11111 (-38)

PAGE 182

182 Figure 8-1. Magnetic component inclination for the C4Ar.1n-C5r.1n interval from ODP Site1092 (Evans and Channell, 2003) compared to the geomagnetic polarity timescale ofCande and Kent (1992; 1995). rmcd= revised meters composite depth.

PAGE 183

183 Figure 8-2. Oxygen isotope records from the C4An-C5r.1n interval at ODP Site 1092. The topframe shows the output of a gaussian filter centered at a frequency of 0.78 m-1 appliedto the stacked "18O record. The stacked "18O record with numbered obliquity cyclesis shown superimposed on the same record with a 5-point smoothing. The three "18Orecords from different planktic and benthic foraminiferal species were used togenerate the stack.

PAGE 184

184 Figure 8-3. a) Power spectrum generated from the oxygen isotope stack in the depth domain(solid line). b) Dashed line is the power spectrum generated from the ETP target(Laskar et al., 2004) and the solid line is the power spectrum generated from thestacked oxygen isotope records after tuning. c) Coherence between the "18O stack andthe ETP target curve, line indicates 95% confidence limit for coherence peaks.

PAGE 185

185 Figure 8-4. Upper plot shows the correlation of the filtered (filter centered at 0.0244 0.0073kyr1) oxygen isotope stack to the astronomical solution for obliquity (Laskar et al.,2004). Lower plot shows the correlation of the three oxygen isotope records from Site1092 to the ETP solution (Laskar et al., 2004). Crosses mark the tie points betweenthe oxygen isotope stack and the ETP curve. Shaded areas indicate critical intervals inthe correlation between the records that facilitate an unambiguous match between theoxygen isotope record and the ETP astronomic solution.

PAGE 186

186 Figure 8-5. Interval sedimentation rates for the C4Ar.1n-C5r.1n interval calculated using the newastrochronology. Asterisks indicate the position of polarity excursions within C5n.2n.

PAGE 187

187 Figure 8-6. Comparison of the age estimates of polarity chrons at ODP Site 1092 (this paper) tothe timescale of Cande and Kent (1992; 1995), to the ATNTS2004 timescale(Lourens et al., 2004), and to the timescales of Hilgen et al. (1995; 2000), and AbdulAziz et al. (2003).

PAGE 188

188 Figure 8-7. The Site 1092 relative paleointensity record for C5n.2n (base), the deep-towmagnetic anomaly record from the East Pacific Rise at 19S (middle) and the revisedNorth Pacific Stack (Bowers et al., 2001). Numbering on the revised North Pacificstack is after [35]. Arrows from above indicate the proposed correlation (Bowers etal., 2001) of CK92 cryptochrons to the revised N. Pacific Stack and the EPR 19Sdeep-tow record. Arrows from below indicate our preferred correlation of the polarityexcursion chrons to the deep-tow record.

PAGE 189

189CHAPTER 9CONCLUSIONS AND FUTURE WORKThe work presented in this dissertation illustrates the spectrum of timescales upon whichthe sedimentary record of the geomagnetic field can be used as a tool for stratigraphiccorrelation. The amount of information that can be gained from a particular sedimentary recorddepends on a number of factors: the type of sediment, the magnetic remanence carrier, the lengthof the record and the geographic location the core was collected. As such, this work hasdemonstrated the enormous possibilities that sedimentary records of the geomagnetic field havein terms of improving our understanding of changes in the geomagnetic field over time, theiruses in stratigraphic correlation on varying timescales, and the importance of environmentalmagnetism to paleoclimatology. As more sedimentary cores are collected from the worldsoceans, our understanding of the paleomagnetic field can only increase.In Brunhes age sediments from the North Atlantic a combination of relative paleointensityand oxygen isotope records have been used to develop paleointensity-assistedchronostratigraphies. Detrital layers identified on the Eirik drift have been placed in apaleointensity-assisted chronostratigraphic framework, allowing improved correlation to otherrecords of detrital layers from the North Atlantic. A new relative paleointensity stack for the 0-85 ka interval has been developed using three new paleointensity records and eight existingrecords. This stack has been placed on the Shackleton-revised GISP chronology by correlation ofa benthic oxygen isotope record to Core MD95-2042 from the Portuguese Margin.Miocene to Pleistocene age sediments from the Pacific and Atlantic Oceans have producedreliable magnetic stratigraphies back to 12 Ma. Integration of the magnetic stratigraphy withcycle stratigraphy has allowed astronomic calibration of the interval from 9.3-11.2 Ma at ODPSite 1092, in the 1-6 Ma interval at ODP Site 1208 and between 2.5 Ma and 6 Ma at IODP Site

PAGE 190

190U1313. Integration with biostratigraphic data has resulted in a new Late Miocene to Recentplanktonic foraminifer biostratigraphic zonation for the northwest Pacific. In Pliocene agesediments from IODP Site U1313 (a re-occupation of DSDP Site 607) a record of relativepaleointensity between 2.5 Ma and 6 Ma is one of only a handful of records for this interval.Even though the geomagnetic polarity timescale has recently been revised with the entireNeogene section of the timescale being astronomically calibrated, much work is still required onolder (Paleogene) parts of the timescale. I have been working on a collaborative project withThomas Westerhold, Ursula Rohl and others to improve the Paleogene GPTS. This has resultedin the compilation of magnetostratigraphic results from two ODP Legs (198 and 208) along withXRF scanning data and other physical properties from the cores, resulting in the firstastronomically calibrated timescale for the Paleocene (Westerhold et al., in preparation). Byintegrating published ODP data and land-based records with ODP Leg 198 and 208 sites, aPaleogene cyclostratigraphy has been accomplished (Westerhold et al., in preparation). The nextphase of this work will be on Eocene age sediments from ODP Leg 198.

PAGE 191

191LIST OF REFERENCESAbdul Aziz, H., Krijgsman, W., Hilgen, F.J., Wilson, D.S., Calvo, J.P., 2003. An astronomicalpolarity timescale for the late middle Miocene based on cyclic continental sequences. J.Geophys. Res.108, 2159, doi:10.1029/2002JB001818.Arthur, M.A., Srivastava, S.P., Kaminski, M., Jarrad, R., Osler J, 1989. Seismic stratigraphy andhistory of deep circulation and sediment drift development in Baffin Bay and the LabradorSea. In: Srivastava, S.P., Arthur, M.A., Clement, B., (Eds.), Proceedings of the ODP, Sci.Results 105. Ocean Drilling Program. College Station, TX, 957-975.Backman, J., Raffi, I., 1997. Calibration of Miocene nannofossil events to orbitally tunedcyclostratigraphies from Ceara Rise. In: Shackleton, N.J., Curry, W.B., Richter, C.,Bralower, T.J. (Eds.). Proceedings of the ODP, Sci. Results 154. Ocean Drilling Program.College Station, TX, 83-99.Backman, J., Pestiaux, P., 1987. Pliocene Discoaster abundance variations, Deep Sea DrillingProject Site 606: Biochronology and paleoenvironmental implications. In: Ruddiman,W.F., Kidd R.B., Thomas, E., Shipboard Scientists. Init. Repts. DSDP 94. Washington,D.C., US Government Printing Office, 903-910.Baksi, A., 1992. A40Ar/39Ar age for the termination of Chron 5; a new calibration point for theMiocene section of the GPTS. Trans. Am. Geophys. Union (EOS) 73, 630.Ballini, M., Kissel, C., Colin, C., Richter, T., 2006. Deep-water mass source and dynamicassociated with rapid climatic variations during the last glacial stage in the North Atlantic:A multiproxy investigation of the detrital fraction of deep-sea sediment. Geochem.Geophys. Geosys. 7, doi:10.1029/2005GC001070.Bassinot, F., Labeyrie, L., Shipboard Scientific Party, 1996. IMAGES MD101, a bord duMarion-Dufresne du 29 mai au 11 juillet 1995, 217 pp., Inst. Francais pour la Rech. et laTechnol. Polaires, Plouzane, France.Baumgartner, S., Beer, J., Masarik, J., Wagner, G. Meynadier, L., Synal, H.-A., 1998.Geomagnetic modulation of the 36Cl flux in the GRIP ice core, Greenland. Science 279,1330-1332.Berger, A., 1988. Milankovitch theory and climate. Rev. Geophys. 26, 624-657.Berger, A. 1978. Long-term variations of daily insolation and Quaternary climatic change. J.Atmos. Sci. 35, 2362-2367.Berger, A., Loutre, M.F., 1991. Insolation values for the climate of the last 10 million years.Quat. Sci. Rev. 10, 297-317.

PAGE 192

192Berggren, W.A., Kent, D.V., Swisher, C.C., Aubry, M-P., 1995a. A revised Cenozoicgeochronology and chronostratigraphy. In: Berggren, W.A., Kent, D.V., Aubry, M-P.,Hardenbol, J., (Eds.). Geochronology time scales and global stratigraphic correlation.SEPM Special publication 54, pp. 129-206.Berggren, WA., Hilgen F.J., Langereis, C.G., Kent, D.V., Obradovich, J.D., Raffi, I., Raymo,M.E., Shackleton, N.J., 1995b. Late Neogene chronology: New perspectives in high-resolution stratigraphy. GSA Bulletin 107, 1272-1287.Berggren, W.A., Kent, D.V., van Couvering J.A., 1985. Neogene geochronology andchronostratigraphy. In: Snelling, N.J. (Ed.). The chronology of the geological record.Geological Society of London Memoir 10, 211-250.Bianchi, G.G., McCave, I.N., 2000. Hydrography and sedimentation under the deep westernboundary current on Bjorn and Gardar Drifts, Iceland Basin. Marine Geology 165, 137-169.Blakely, R.J., 1974. Geomagnetic reversals and crustal spreading rates during the Miocene. J.Geophys. Res. 79, 2979-2985.Bodn, P., Backman, J., 1996. A laminated sediment sequence from northern North AtlanticOcean and its climatic record. Geology 24, 507.Bolli, H.M., Saunders, J.B., 1985a. Oligocene to Holocene low latitude planktonic foraminifera.In: Bolli, H.M., Saunders, J.B., Perch-Nielsen, K. (Eds.). Plankton Stratigraphy,Cambridge, Cambridge University Press, pp. 155-262.Bolli, H.M., Saunders, J.B., Perch-Neilsen, K., 1985b. Introduction to the foraminiferal chapters.In: Bolli, H.M., Saunders, J.B., Perch-Nielsen, K., (Eds.). Plankton Stratigraphy,Cambridge, Cambridge University Press, pp. 11-16.Bond, G.C., Showers, W., Elliot, M., Evans, M., Lotti, R., Hajdas, I., Bonani, G., Johnson, S.,1999. The North Atlantic's 1-2 kyr climate rhythm: relation to Heinrich Events,Dansgaard/Oeschger Cycles and the Little Ice Age. In: Clark, P.U., Webb R.S., Keigwin,L.D., (Eds.). Mechanisms of global climate change at millennial time scales. GeophysicalMonograph 112, 35-58.Bowers, N.E., Cande, S.C., Gee, J., Hildebrand, J.A., Parker, R.L., 2001. Fluctuations of thepaleomagnetic field during chron C5 as recorded in near bottom marine magnetic anomalydata. J. Geophys. Res. 106, 26,379-26,396.Bowles, J., Tauxe, L., Gee, J., McMillan, D., Cande S., 2003. Source of tiny wiggles in ChronC5: A comparison of sedimentary relative intensity and marine magnetic anomalies.Geochem. Geophys. Geosyst. 4, 1049, doi:10.1029/2002GC000489.Bown, P.R., 2005. Cenozoic calcareous nannofossil biostratigraphy, ODP Leg 198 Site 1208(Shatsky Rise, northwest Pacific Ocean). In: Bralower, T.J., Premoli-Silva, I., Malone,M.J. (Eds.), Proceedings of the ODP, Sci. Results 198, 1 [Online].

PAGE 193

193Bown, P.R.,Young, J.R., 1998. Techniques. In Bown, P.R. (Ed.), Calcareous nannofossilbiostratigraphy: Dordrecht, The Netherlands (Kluwer Academic Publ.), pp. 16.Bralower, T.J., Premoli Silva, I., Malone, M.J., The Shipboard Scientific Party, 2002.Proceedings of the ODP, Init. Repts. 198 [CD-ROM]. Ocean Drilling Program, TexasA&M University, College Station, TX.Broecker, W., Denton, G.H., 1989. The role of ocean-atmosphere reorganizations in glacialcycles. Geochimica et Cosmochimica Acta 53, 2465-2501.Bukry, D., 1973. Low-latitude coccolith biostratigraphic zonation. In: Edgar, N.T., Saunders,J.B., and Shipboard Scientists. Init. Repts. DSDP, 15, Washington (U.S. Govt. PrintingOffice), 685.Bukry, D., 1975. Coccolith and silicoflagellate stratigraphy, northwestern Pacific Ocean, DeepSea Drilling Project Leg 32. In: Larson, R.L., Moberly, R., Shipboard Scientists. Init.Repts. DSDP, 32. Washington (U.S. Govt. Printing Office), 677.Cande, S.C., Kent, D.V., 1992. A new geomagnetic polarity timescale for the late Cretaceousand Cenozoic. J. Geophys. Res. 97, 13917-13951.Cande, S.C., Kent, D.V., 1995. Revised calibration of the geomagnetic polarity timescale for thelate Cretaceous and Cenozoic, J. Geophys. Res. 100, 6093-6095.Censarek, B., Gersonde, R., 2002. Miocene diatom biostratigraphy at ODP sites 689, 690, 1088,1092 (Atlantic sector of the Southern Ocean). Marine Micropaleontology 45, 309-356.Channell, J.E.T., 1999. Geomagnetic paleointensity and directional secular variation at OceanDrilling Program (ODP) Site 984 (Bjorn Drift) since 500 ka: Comparisons with ODP Site983 (Gardar Drift). J. Geophys. Res. 104, 22,937-22,951.Channell, J.E.T., D.A. Hodell, B. Lehman, 1997. Relative geomagnetic paleointensity and "18Oat ODP Site 983 (Gardar Drift, North Atlantic) since 350 ka. Earth Planet. Sci. Lett. 153,103-118.Channell, J.E.T., Labs, J., Raymo, M.E., 2003. The Reunion subchronozone at ODP Site 981(Feni Drift, North Atlantic). Earth Planet. Sci. Lett. 215, 1-12.Channell, J.E.T., Mazaud, A., Sullivan, P., Turner, S., Raymo, M.E., 2002. Geomagneticexcursions and paleointensities in the 0.9-2.15 Ma interval of the Matuyama Chron at ODPSites 983 and 984 (Iceland Basin). J. Geophys. Res. 107, doi:10.1029/2001JB000491.Channell, J.E.T., Kanamatsu, T., Sato, T., Stein, R., Alvarez Zarikian, C.A., Malone, M.J.,Expedition 303/306 Scientists, 2006. Proceedings IODP, 303/306. College Station TX(Integrated Ocean Drilling Program Management International, Inc.).doi:10.2204/iodp.proc.303306.104.

PAGE 194

194Charles, C.D., Lynch-Stieglitz, J., Ninnemann, U.S., Fairbanks, R.G., 1996. Climate connectionsbetween the hemispheres revealed by deep sea sediment core/ice core correlations. EarthPlanet. Sci. Lett. 142, 19-28.Chough, S.K., Hesse, R., 1985. Contourites from Eirik Ridge, south of Greenland. SedimentaryGeology 41, 185-199.Clemens, S.C., 1999. An astronomical tuning stratigraphy for Pliocene sections: implications forglobal-scale correlation and phase relationship. In: Shackleton, N.J., McCave, I.N.,Weedon, G.P., (Eds.). Phil. Trans. R. Soc. Lond. A, 1949-1973.Clement, B. M., Robinson, F., 1986. The magnetostratigraphy of Leg 94 sediments, In:Ruddiman, W.F., Kidd, R. B., Thomas, E., Shipboard Scientists, Init. Repts. DSDP 94:Washington (U.S. Government Printing Office), 635-650Day, R., Fuller, M., Schmidt, V.A., 1977. Hysteresis properties of titanomagnetites: grain-sizeand compositional dependence. Phys. Earth Planet. Int. 13, 260-267.Evans, H.F., Channell, J.E.T., Sager, W.W., 2005. Late MioceneHolocene magnetic polaritystratigraphy and astrochronology, ODP Leg 198, Shatsky Rise. In: Bralower, T.J., PremoliSilva, I., Malone, M.J. (Eds.), Proceedings ODP, Sci. Results 198 [CD-ROM]. OceanDrilling Program. Texas A&M University College Station, TX, 1-39.Evans H.F., Westerhold, T., Channell, J.E.T., 2004. ODP Site 1092: revised composite depthsection has implications for Upper Miocene "cryptochrons". Geophys. J. Inter. 156, 195-199.Evans H.F., Channell, J.E.T., 2003. Upper Miocene magnetic stratigraphy at ODP Site 1092(sub-Antarctic South Atlantic): recognition of cryptochrons in C5n.2n. Geophys. J. Inter.153, 483-496.Evans, H.F., Channell, J.E.T., Stoner, J.S., Hillaire-Marcel, C., Wright, J.D., Neitzke, L.C.,Mountain G.S., submitted. Paleointensity-assisted chronostratigraphy of detrital layers onthe Eirik Drift (North Atlantic) since marine isotope stage 11. Geochem. Geophys.Geosyst. Submitted.Expedition 303 Scientists, 2006. Site U1304. In: Channell, J.E.T., Kanamatsu, T., Sato, T., Stein,R., Alvarez Zarikian, C.A., Malone, M.J., Expedition 303/306 Scientists. ProceedingsIODP, 303/306: College Station TX (IODP Management International, Inc.).doi:10.2204/iodp.proc.303306.104.Expedition 306 Scientists, 2006. Expedition 306 summary. In: Channell, J.E.T., Kanamatsu, T.,Sato, T., Stein, R., Alvarez Zarikian, C.A., Malone, M.J., Expedition 303/306 Scientists.Proceedings IODP, 303/306: College Station TX (IODP Management International, Inc.).doi:10.2204/iodp.proc.303306.109.

PAGE 195

195Funder, S., Hjory, C., Landvik, J. Y., Nam, S-I., Reeh, N., Stein, R., 1998. History of a stable icemarginEast Greenland during the Middle and Upper Pleistocene. Quat. Sci. Rev. 17, 77-123.Gradstein, F., Ogg, J., Smith A., 2005. A Geologic time scale 2004. Cambridge, CambridgeUniversity Press, pp. 589.Grootes, P.M., Stuvier, M., 1997. Oxygen 18/16 variability in Greenland snow and ice with 1033to 105-year time resolution. J. Geophys. Res. 102, 26,455-26,470.Gubbins, D., 1999. The distinction between geomagnetic excursions and reversals. Geophys. J.Inter. 137, F1-F3.Guyodo, Y., Channell, J.E.T., Thomas, R.G., 2003. Deconvolution of u-channel paleomagneticdata near geomagnetic reversals and short events. Geophys. Res. Letters 29, 1845,doi:10.1029/2002GL014963.Hagelberg. T.K., Pisias, N.G., Shackleton N.J., Mix, A.C., Harris S., 1995. Refinement of a high-resolution, continuous sedimentary section for studying equatorial Pacific Oceanpaleoceanography, Leg 138. In: Pisias, N.G., Mayer, L.A., Janecek, T.R. Palmer-Julson,A., van Andel, T.H., (Eds.). Proceedings ODP Sci., Res. 138. Ocean Drilling Program,College Station, TX, 31-46.Harland, W.B., Cox, A.V. Llewellyn, P.G., Pickton, C.A.G., Smith, A.G., Walters, R., 1982. AGeologic Time Scale. Cambridge Univ. Press, Cambridge.Harland, W.B., Armstrong, R., Cox, A.V., Craig, L., Smith, A., Smith, D., 1990. A GeologicTime Scale 1989. Cambridge Univ. Press, Cambridge.Hemming, S., 2004. Heinrich Events: Massive Late Pleistocene detritus layers of the NorthAtlantic and their global imprint. Rev. Geophys. 42, RG1005,doi:10.1029/2003RG000128.Heirtzler, J.R., Dickson, G.O., Herron, E.M., Pittman, W.C., III, LePichon, X., 1968. Marinemagnetic anomalies, geomagnetic field reversal and motions of the ocean floor andcontinents. J. Geophys. Res. 73, 2119-2136.Hilgen, F.J., 1991a. Astronomical calibration of Gauss to Matuyama sapropels in theMediterranean and implication for the Geomagnetic Polarity Time Scale. Earth Planet. Sci.Lett. 104, 226-244.Hilgen, F.J., 1991b. Extension of the astronomically calibrated (polarity) time scale toMiocene/Pliocene boundary. Earth Planet. Sci. Lett. 107, 349-368.Hilgen, F.J., Krijgsman, W., Langereis, C.G., Lourens, L.J., Santarelli, A., Zachariasse, W.J.,1995. Extending the astronomical (polarity) time scale into the Miocene. Earth Planet. Sci.Lett. 136, 495-510.

PAGE 196

196Hilgen, F.J., Krijgsman, W., Raffi, I., Turco, E., Zachariasse, W.J., 2000. Integrated stratigraphyand astronomical calibration of the Serravallian/Tortonian boundary section at MonteGibliscemi (Sicily, Italy). Marine Micropaleontology 38, 181-211.Hilgen, F.J., Abdul Aziz, H., Krijgsman, W., Raffi, I., Turco, E., 2003. Integrated stratigrpahyand astronomical tuning of the Serravallian and lower Tortonian at Monti dei Corvi(Middle-Upper Miocene, northern Italy). Palaeogeography, Palaeoclimatology,Palaeoecology 199, 229-264.Hillaire-Marcel, C., Bilodeau, G., 2000. Instabilities in the Labrador Sea water mass structureduring the last climatic cycle. Can. J. Earth Sci. 37, 795-809.Hillaire-Marcel, C., De Vernal, A. Bilodeau, G., Wu, G., 1994. Isotope stratigraphy,sedimentation rates, deep circulation, and carbonate events in the Labrador Sea during thelast ~200 ka. Can. J. Earth Sci. 31, 63-89.Hiscott, R.N., Aksu, A.E., Mudie, P.J., Parsons, D.F., 2001. A 340,000 year record of ice rafting,paleoclimatic fluctuations, and shelf crossing glacial advances in the southwesternLabrador Sea. Global and Planetary Change 28, 227-240.Hodell, D.A., Charles, C.D., Sierro, F.J., 2001. Late Pleistocene evolution of the ocean'scarbonate system. Earth Planet. Sci. Lett. 192, 109.Hodell, D.A., Kennett, JP., 1986. Late Miocene-early Pliocene stratigraphy andpaleoceanography of the South Atlantic and southwest Pacific Oceans: A synthesis.Paleoceanography 1, 285-311.Hollerbach, R., Jones, C.A., 1995. On the magnetically stabilizing role of the Earths inner core,Phys. Earth Planet. Inter. 87, 171-181.Iaccarino, S., 1985. Mediterranean Miocene and Pliocene planktic foraminifera. In: Bolli, H.M.,Saunders, J.B., Perch-Nielsen, K. (Eds.). Plankton Stratigraphy, Cambridge, CambridgeUniversity Press, pp. 283-314.Jenkins, D.G., 1985. Southern and mid-latitude Paleocene to Holocene planktic foraminifera. In:Bolli, H.M., Saunders, J.B., Perch-Nielsen, K. (Eds.). Plankton Stratigraphy, Cambridge,Cambridge University Press, pp. 263-282.Jouzel, J., Lorius, C., Petit, J.R., Genthon, C., Barkov, N.I., Kotlyakov, V.M., Petrov, V.M.,1987. Vostok ice core: a continuous isotope temperature record over the last climatic cycle(160 000 years). Nature 329, 402-408.Kawase, M., Sarmiento, J.L., 1986. Circulation and nutrients in middepth Atlantic waters, J.,Geophys. Res. 91, 9748-9770.Keller, G., 1979a, Late Neogene planktonic foraminiferal biostratigraphy and paleoceanographyof the northwest Pacific DSDP Site 296. Palaeogeography Palaeoclimatology,Palaeoecology 27, 129-154.

PAGE 197

197Keller, G., 1979b. Late Neogene paleoceanography of the North Pacific DSDP Sites 173, 310and 296. Marine Micropaleontology 4, 159-172.Keller, G., 1979c. Early Pliocene to Pleistocene planktonic foraminiferal datum levels in theNorth Pacific: DSDP Sites 173, 310, 296. Marine Micropaleontology 4, 281-294.Kennett, J.P., Srinivasan, M., 1983. Neogene Planktonic Foraminifera: A phylogenetic atlas:Stroudsberg, Hutchinson Ross Publishing Co. pp. 265.King, J.W., Banerjee, S.K., Marvin, J., 1983. A new rock-magnetic approach to selectingsediments for geomagnetic paleointensity studies: application to paleointensity for the last4000 years. J. Geophys. Res. 88, 5911-5921.Kirschvink, J.L., 1980. The least squares lines and plane analysis of palaeomagnetic data.Geophys. J. R. Astr. Soc. 62, 699-718.Kissel, C., Laj, C., Labeyrie, L., Dokken, T., Voelker, A., Blamart, D., 1999. Rapid climaticvariations during marine isotope stage 3: magnetic analysis of sediments from the NordicSeas and North Atlantic. Earth Planet. Sci. Lett. 171, 489-502.Kok, Y.S., Tauxe, L., 1996a. Saw-toothed pattern of relative paleointensity records andcumulative viscous remanence. Earth Planet. Sci, Lett. 137, 95-99.Kok, Y.S., Tauxe, L., 1996b. Saw-toothed pattern of sedimentary paleointensity recordsexplained by cumulative viscous remanence. Earth Planet. Sci. Lett. 144, 9-14.Krijgsman W., Kent, D.V. 2004. Non-uniform occurrences of short-term polarity fluctuations inthe geomagnetic field? New results from Middle to Late Miocene sediments from theNorth Atlantic. In: Timescales of the paleomagnetic field. Channell, J.E.T., Kent, D.V.,Lowrie, W., Meert, J. G. (Eds.). AGU Geophysical Monograph 145, 161-174.Laj, C., Kissel, C., Beer, J., 2004. High resolution global paleointensity stack since 75 kyr(GLOPIS-75) Calibrated to absolute values. In: Timescales of the paleomagnetic field.Channell, J.E.T., Kent, D.V., Lowrie, W., Meert, J. G. (Eds.). AGU GeophysicalMonograph 145, 255-265.Laj, C., Kissel, C., Mazaud, A., Channell, J.E.T., Beer, J., 2000. North Atlantic paleointensitystack since 75 ka (NAPIS-75) and the duration of the Laschamp event. Phil. Trans. Roy.Soc. 358, 1009-1025.Laskar, J., Joutel, H., Boudin, F., 1993. Orbital, precessional and insolation quantities for theEarth from Myr to +10 Myr. Astron. Astrophys. 270, 522-533.Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A.C.M., Levrard, B., 2004. A longterm numerical solution for the insolation quantities of the Earth. Astron. Astrophys. 428,261-285.

PAGE 198

198Lisiecki L., Raymo, M., 2005. A Pliocene-Pleistocene stack of 57 globally distributed benthic"18O records. Paleoceanography 20, doi:10.1029/2004PA001071.Lourens, L.J., Hilgen, F.J., Laskar, J., Shackleton, N.J., Wilson D., 2004. The Neogene Period.In: Gradstein, F.M., J.G. Ogg, A.G. Smith, (Eds.). Geologic Time Scale 2004. CambridgeUniv. Press, pp. 409-440.Lucotte, M., Hillaire-Marcel, C., 1994. Identification et distribution des grandes masses d'eaudans les mers du Labrador et d'Irminger. Can. J. Earth Sci. 31, 5-13.Lund, S.P., Acton, G., Clement, B., Hastedt, M., Okada, M., Williams, T., Shipboard ScientificParty, 1998. Geomagnetic field excursions occurred often during the last million years.Trans. Am. Geophys. Union (EOS) 79, 178.Maenaka, K., 1983. Magnetostratigraphic study of the Osaka Group, with special reference to theexistance of pre and post-Jaramillo episodes in the Late Matuyama polarity epoch. Mem.Hanazono Univ. 14, 1-65.Martinson, D.G., Pisias, N. G., Hays, J.D., Imbrie, J., Moore, T.C., Shackleton, N.J., 1987. Agedating and the orbital theory of the Ice Ages: development of a high-resolution 0 to300,000-year chronostratigraphy. Quat. Res. 27, 1-29.Mazaud, A., 1996. 'Sawtooth' variation in magnetic intensity profiles and delayed acquisition ofmagnetization in deep sea cores. Earth Planet. Sci. Lett. 139, 379-386.McCartney, M.S., 1992. Recirculating components to the deep boundary current of the northernNorth Atlantic. Prog. Oceanog. 29, 283-383.McCave, I.N., Tucholke, B.E., 1986. Deep current-controlled sedimentation in the western NorthAtlantic. In: The geology of North America: The Western Atlantic region. Vogt, P.R.,Tucholke, B.E., (Eds.). Geol. Soc. Am., DNAG Ser., Boulder, CO., Vol., M Spec. Publ.,pp. 451-468.McCave, I. N., Manighetti, B., Robinson, S.G., 1995. Sortable silt and fine sediment slicing:Parameters for paleocurrent speed and paleoceanography. Paleoceanography 10, 593-610.Meese, D.A., Gow, A. J., Alley, R.B., Zielinski, G.A., Grootes, P.M., Ram, M., Taylor, K.C.,Mayewski, P.A., Bolzan, J.F., 1997. The Greenland Ice Sheet Project 2 depth-age scale:Methods and results. J. Geophys. Res. 102, 26,411-26,423.Meynadier, L., Valet, J-P., Bassinot, F., Shackleton, N.J., Guyodo, Y., 1994. Asymmetrical saw-tooth pattern of the geomagnetic field intensity from equatorial sediments in the Pacificand Indian Oceans. Earth Planet. Sci. Lett. 126, 109-127.Miller, K.G., Tucholke, B.E., 1983. Development of Cenozoic abyssal circulation south of theGreenlandScotland Ridge. In: Bott, M.H.P. (Ed.), Structure and Development of theGreenlandScotland Ridge: New Methods and Concepts. Plenum Press, New York, pp.549.

PAGE 199

199Moreno, E., Thouveny, N., Delanghe, D., McCave, I.N., Shackleton, N.J., 2002. Climatic andoceanographic changes in the Northeast Atlantic reflected by magnetic properties ofsediments deposited on the Portuguese Margin during the last 340 ka. Earth Planet. SciLett. 202, 465-480.Muscheler, R., Beer, J., Kubik, P.W., Synal, H.-A., 2005. Geomagnetic field intensity during thelast 60,000 years based on 10Be and 36Cl from the Summit ice cores and 14C. Quat. Sci.Reviews 24, 1849-1860.Ness, G., Levi, S., Couch, R., 1980. Marine magnetic anomaly timescales for the Cenozoic andLate Cretaceous: A precis, critique and synthesis. Reviews of Geophysics and SpacePhysics 18, 4, 753-770.Okada, H., Bukry, D., 1980. Supplementary modification and introduction of code numbers tothe low-latitude coccolith biostratigraphic zonation (Bukry, 1973; 1975). MarineMicropaleontology 5, 321.Opdyke, N.D., Glass, B., Hays, J.P., Foster, J., 1966. Paleomagnetic study of Antarctica deep-seacores. Science 154, 349-357.Opdyke, N.D., Channell, J.E.T., 1996. Magnetic stratigraphy. Academic Press, San Diego, Calif.,346 pp.Paillard, D., Labeyrie, L., Yiou, P., 1996. Macintosh program performs time-series analysis,Trans. Am. Geophys. Union, EOS 77, 379.Paulsen, H., Westerhold, T., Bickert, T., in press. Middle to Late Miocene oxygen isotopestratigraphy of the Southern Ocean. Geology, in press.Raffi, I., Flores, J-A., 1995. Pleistocene through Miocene calcareous nannofossils from easternequatorial Pacific Ocean (ODP Leg 138). In: Pisias, N.G., Mayer, L.A., Janecek, T.R.Palmer-Julson, A., van Andel, T.H., (Eds.). Proceedings ODP, Sci., Res. 138. OceanDrilling Program, College Station, TX, 59-72.Raymo, M.E., Ruddiman, W.F., Backman, J., Clement, B.M., Martinson, D.G., 1989. LatePliocene variation in Northern Hemisphere ice sheets and North Atlantic Deep Watercirculation. Paleoceanography 4, 413.Rea, D.K., Basov, I.A., Janecek, T.R., Palmer-Julson, A., Shipboard Scientific Party 1993.Proceedings ODP, Init. Repts., 145, College Station, TX, ODP.Rio, D., Raffi, I., Villa, G., 1990. Pliocene-Pleistocene calcareous nannofossil distributionpatterns in the western Mediterranean. In: Kastens, K.A., Mascle, J. Proceedings of theODP, Sci. Res., Leg 107. Ocean Drilling Program, College Station, TX, ODP, 513-533.Roberts, A.P., Lewin-Harris, J.C., 2000. Marine magnetic anomalies: evidence that tinywiggles represent short-period geomagnetic polarity intervals. Earth Planet. Sci. Lett. 183,375.

PAGE 200

200Rhl, U., Abrams, L.J., 2000. High-resolution, downhole, and non-destructive coremeasurements from Sites 999 and 1001 in the Caribbean Sea: application to the LatePaleocene Thermal Maximum. In: Leckie, R.M., Sigurdsson, H., Acton, G.D., Draper G.(Eds.). Proceedings ODP, Sci. Res. 165. Ocean Drilling Program, College Station, TX,191-203.Ruddiman, W.F., Raymo, M., McIntyre, A., 1986. Matuyama 41,000-year cycles: North AtlanticOcean and northern hemisphere ice sheets. Earth Planet. Sci. Lett. 80:117.Ruddiman, W.F., Kidd, R.B., Thomas, E., Shipboard Scientific Party 1987. Init. Repts. DSDP,94 (Pts. 1 and 2), Washington (U.S. Govt. Printing Office).Schneider, D.A., 1995. Paleomagnetism of some Leg 138 sediments: detailing Miocenemagnetostratigraphy, In: Pisias, N.G., Mayer, L.A., Janecek, T.R. Palmer-Julson, A., vanAndel, T.H., (Eds.). Proceedings ODP Sci., Res. 138. Ocean Drilling Program, CollegeStation, TX, 59-72.Shackleton, N.J., Fairbanks, R.G., Chiu, T.-C., Parrenin, F., 2004. Absolute calibration of theGreenland time scale: implications for Antarctic time scales and for #14C. Quat. Sci.Reviews 23, 1513-1522.Shackleton, N.J., Crowhurst, S., 1997. Sediment fluxes based on an orbitally tuned time scale 5Ma to 14 Ma, Site 926. In: Shackleton, N.J., Curry, W.B., Richter, C., Bralower, T.J.(Eds.). Proceedings ODP Sci., Res. 154. Ocean Drilling Program. College Station, TX 69-82.Shackleton, N.J., Crowhurst, S., Hagelberg., T., Pisias, N.G., Schneider, D.A., 1995. A new LateNeogene time scale: application to Leg 138 sediments. In: Pisias, N.G., Mayer, L.A.,Janecek, T.R. Palmer-Julson, A., van Andel, T.H., (Eds.). Proceedings ODP Sci., Res. 138.Ocean Drilling Program, College Station, TX, 73-101.Shackleton, N.J., Baldauf, J.G., Flores, J-A., Iwai, M., Moore, T.C., Raffi, I., Vincent, E., 1995a.Biostratigraphic summary for Leg 138. In: Pisias, N.G., Mayer, L.A., Janecek, T.R.Palmer-Julson, A., van Andel, T.H., (Eds.). Proceedings ODP Sci., Res. 138. OceanDrilling Program, College Station, TX, 73-101.Shackleton, N.J., Berger, A., Peltier, W.R., 1990. An alternative astronomical calibration of thelower Pleistocene timescale based on ODP site 677. Trans. R. Soc. Edinburgh 81, 251-261.Shackleton, N. J., Hall, M. A., Boersma, A., 1984. Oxygen and carbon isotope data from Leg 74foraminifers, Init. Rep. DSDP 74, Washington (U.S. Govt. Printing Office), 599.Shipboard Scientific Party, 1999. Site 1092. In: Gersonde, R., Hodell, D.A., Blum, P., ShipboardScientific Party. Proceedings ODP Init. Repts. 177, Ocean Drilling Program, CollegeStation, TX, 1-82.

PAGE 201

201Shipboard Scientific Party, 2002a. Leg 198 Summary. In: Bralower, T.J. Premoli-Silva I.,Malone M., Shipboard Scientific Party. Proceedings ODP, Init. Repts. 198 [CD-ROM],College Station, TX (Ocean Drilling Program) 1-148.Shipboard Scientific Party, 2002b. Site 1208. In Bralower, T.J., Premoli Silva, I., Malone, M.J.,Shipboard Scientific Party. Proc. ODP, Init. Repts., 198: College Station, TX (OceanDrilling Program), 1. doi:10.2973/odp.proc.ir.198.104.2002.Singer. B.S., Hoffman, K.A., Chauvin, A., Coe, R.S., Pringle, M.S., 1999. Dating transitionallymagnetized lavas of the late Matuyama chron: Toward a new 40Ar/39Ar timescale ofreversals and events. J. Geophys. Res. 104, 679-693.Snowball, I., Sandgren, P., 2004. Geomagnetic field intensity changes in Sweden between 9000and 450 cal BP: extending the record of archaeomagnetic jerks by means of lake sedimentsand the pseudo-Thellier technique. Earth Planet. Sci Lett. 227, 361-376.Snowball, I., Moros, M., 2003. Saw-tooth pattern of North Atlantic current speed duringDansgaard-Oeschger cycles revealed by the magnetic grain size of Reykjanes Ridgesediments at 59 N. Paleoceanography 18, doi:10.1029/2001PA000732.Srinivasan, M.S., Sinha, D.K., 1993. Late Neogene planktonic foraminiferal events of thesouthwest Pacific and Indian Ocean: A comparison. In: Tsuchi, R., Ingle, J.C., Eds. PacificNeogene environment, evolution and events: Tokyo, University of Tokyo Press, pp. 203-220.Srivastava, S.P., Tapscott, C.R., 1986. Plate kinematics of the North Atlantic. In: The Geology ofNorth America: The Western Atlantic Region. Vogt, P.R., Tucholke, B.E., (Eds.), Geol.Soc. Am., DNAG Ser., Boulder, CO., Vol., M, Spec. Publ., p. 589-604.Stoner, J.S., Channell, J.E.T., Hodell, D.A., Charles, C., 2003. A 580 kyr paleomagnetic recordfrom the sub-Antarctic South Atlantic (ODP Site 1089). J. Geophys. Res. 108,doi:10.1029/2001JB001390.Stoner, J.S., Laj, C., Channell, J.E.T., Kissel, C., 2000. South Atlantic (SAPIS) and NorthAtlantic (NAPIS) geomagnetic paleointensity stacks (0-80 ka): implications for inter-hemispheric correlation. Quat. Sci. Reviews 21, 1141-1151.Stoner, J.S., Channell, J.E.T., Hillaire-Marcel, C., 1996. The magnetic signature of rapidlydeposited detrital layers from the deep Labrador Sea: Relationship to North AtlanticHeinrich layers. Paleoceanography 11, 309-325.Stoner, J.S., Channell, J.E.T., Hillaire-Marcel, C., 1995a. Late Pleistocene relative geomagneticpaleointensity from the deep Labrador Sea: Regional and global correlations. Earth Planet.Sci. Lett. 134, 237-252.Stoner, J.S., Channell, J.E.T., Hillaire-Marcel, C., 1995b. Magnetic properties of deep-seasediments off southwest Greenland: Evidence for major differences between the last twodeglaciations. Geology 23, 241-244.

PAGE 202

202Tauxe, L., 1993. Sedimentary records of relative paleointensity of the geomagnetic field: Theoryand practice. Rev. Geophys. 31, 319-354.Tauxe, L., Hartl, P., 1997. 11 million years of Oligocene geomagnetic field behaviour. Geophys,J. Int. 128, 217-229.Tauxe, L., Pick, T., Kok, Y.S., 1995. Relative paleointensity in sediments: a pseudo-Thellierapproach. Geophys. Res. Lett. 22, 2885-2888.Tauxe, L., Shackleton, N.J., 1994. Relative palointensity records from the Ontong-Java Plateau.Geophys. J. Int. 117, 769-782.Thibal, J., J. P. Pozzi, V. Barthe`s, Dubuisson, G., 1995. Continuous record of geomagnetic fieldintensity between 4.7 and 2.7 Ma from downhole measurements. Earth. Planet. Sci. Lett.136, 541.Thomas, R., Guyodo, Y., Channell, J.E.T., 2004. U-channel track for susceptibilitymeasurements. Geochem. Geophys. Geosyst. 1050, doi: 10.1029/2002GC000454Tian, J., Wang, P., Cheng, X., Li, Q., 2002. Astronomically tuned Plio-Pleistocene benthic "18Orecord from South China Sea and Atlantic-Pacific comparison. Earth Planet. Sci. Lett. 203,1015-1029.Turon, J.-L., Hillaire-Marcel, C., Shipboard Participants, 1999. IMAGES V mission of theMarion Dufresne. Leg 2, 30 June to 24 July 1999. Geol. Surv. Canada, Open File 3782.Valet, J-P. Time variations in geomagnetic intensity, 2003. Rev. Geophys. 41,doi:10.1029/2001RG000104.Valet, J-P., Meynadier, L., 1993. Geomagnetic field intensity and reversals during the past fourmillion years. Nature 366, 234-238.Van Kreveld, S.A., Knappertsbusch, M., Ottens, J., Ganssen, G., van Hinte, J., 1996. Biogeniccarbonate and ice-rafted debris (Heinrich layer) accumulation in deep-sea sediments from aNortheast Atlantic piston core. Mar. Geol. 131, 21-46.Venti, N.J., 2006. Revised Late Neogene mid-latitude planktic foraminiferal biostratigraphy forthe Northwest Pacific (Shatsky Rise), ODP Leg 198. MS Thesis, University ofMassachusetts.Venz, K.A., Hodell, D.A., Stanton, C., Warnke, D.A, 1999. A 1.0 Myr record of Glacial NorthAtlantic Intermediate Water Variability from ODP Site 982 in the northeast Atlantic.Paleoceanography 14, 42-52.Voelker, A., Sarnthein, M., Grootes, P. M., Erlenkeuser, H., Laj, C., Mazaud, A., Nadeau, M.J.,Schleicher, M., 1998. Correlation of marine 14C ages from the Nordic sea with GISP2isotope record: implication for 14C calibration beyond 25 ka BP. Radiocarbon 40, 517-534.

PAGE 203

203Westerhold T., Roehl, U., Raffi, I., Bowles, J., Evans, H.F., in preparation. The first completeorbital chronology for the Paleocene: Implications for the Geomagnetic Polarity TimeScale and the age of the K-T boundary.Yamazaki, T., Oda, H., 2005. A geomagnetic paleointensity stack between 0.8 and 3.0 Ma fromequatorial Pacfic sediment cores. Geochem. Geophys. Geosys. 11,doi:10.1029/2005GC001001.Yang, S., Odah, H., Shaw, J., 2000. Variations in the geomagnetic dipole moment over the last12,000 years. Geophys. J. Int. 140, 158-162.Young, J.R., 1998. Neogene. In Bown, P.R. (Ed.). Calcareous Nannofossil Biostratigraphy.Dordrecht, The Netherlands (Kluwer Academic Publ.), pp. 225.

PAGE 204

204BIOGRAPHICAL SKETCHHelen F. Evans was born in Swansea, South Wales, in 1977 to Terry and Eryl Evans.Growing up in an area of outstanding natural beauty she gained an interest at a young age ingeology and natural sciences. She earned three A-levels in geology, chemistry and biology fromGowerton Comprehensive School in 1995. The same year she began an undergraduate career atImperial College of Science, Technology and Medicine, in London. She graduated with honorsin 1998 with a BSc. in geology with paleontology and Associateship of the Royal School ofMines (ARSM). After taking a year out she moved to the University of Florida to continue hereducation in geology. She gained a MS in Geology from the University of Florida in 2001 with athesis entitled "Late Miocene to Pleistocene Magnetic Stratigraphy at ODP Site 1092(subantarctic South Atlantic)". During her stay at the University of Florida, Helen was awarded aMcLaughlin Dissertation Fellowship, the University Womens Club Graduate StudentScholarship and an outstanding academic achievement award from the College of Liberal Artsand Sciences. She also spent seven weeks at sea aboard the JOIDES Resolution during a researchcruise to the North Atlantic. Helen is a member of the American Geophysical Union and theGeological Society of America. She has been an author on sixteen abstracts presented atinternational meetings and six peer-reviewed journal articles.


Permanent Link: http://ufdc.ufl.edu/UFE0017566/00001

Material Information

Title: Magnetic Stratigraphy and Environmental Magnetism of Oceanic Sediments
Physical Description: Mixed Material
Copyright Date: 2008

Record Information

Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
System ID: UFE0017566:00001

Permanent Link: http://ufdc.ufl.edu/UFE0017566/00001

Material Information

Title: Magnetic Stratigraphy and Environmental Magnetism of Oceanic Sediments
Physical Description: Mixed Material
Copyright Date: 2008

Record Information

Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
System ID: UFE0017566:00001


This item has the following downloads:


Full Text





MAGNETIC STRATIGRAPHY AND ENVIRONMENTAL MAGNETISM OF OCEANIC
SEDIMENTS



















By

HELEN F. EVANS


A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA

2006

































Copyright 2006

by

Helen F. Evans


































For Jane and Eryl









ACKNOWLEDGMENTS

I would like to thank my advisor, Jim Channell, for giving me the opportunity to study in

Florida and for all his help and support over the last 7 years. I also thank my committee members

Ellen Martin, Neil Opdyke, John Jaeger and Bo Gustafson for agreeing to supervise my research

over the last five years and for all their help, academic and otherwise. I also had the pleasure of

collaborating and interacting with a number of talented individuals without whose help I would

not have been able to accomplish this work: Gary Acton, Paul Bown, Yohan Guyodo, Sean

Higgins, Claude Hillaire-Marcel, Dave Hodell, Kainian Huang, Mark Leckie, Ulla Rohl, Joseph

Stoner, Ray Thomas, Thomas Westerhold and many others. My research was made possible by

the technical and financial support of several organizations including the National Science

Foundation, the JOIDES U.S. Sciences Support Advisory Committee (USSAC), and the

Graduate Student Council. Support was also provided by the Institute for Rock Magnetism, the

College of Liberal Arts and Sciences, the Graduate School, the McLaughlin family, and the

department of Geological Sciences at the University of Florida.

I thank all those who gave me their moral support during my years of study, which often

consisted of many hours of festivities in the numerous bars and restaurants in Gainesville, San

Francisco and further afield. I thank in particular Gillian Rosen, Joe Graves, Joann and Jason

Hochstein, Howie Scher, George and Katherin Kamenov, Cara Gentry, Jen Mays, Steve Volpe,

Phil D'Amo, Bricky Way, Kendall Fountain, Adi Gilli, Simon Nielsen, Dave Hodell, Mike

Rosenmeier, William Kenney, Yohan Guyodo and Victoria Meija. Finally I would like to

express my gratitude to my family without whose support I would not have been able to

complete this work. I thank my late mother Eryl, my father Terry and my brother Michael. I also

thank Diane and John Thomas, Judy and Robin Ganz, and Molly and Reg Beynon.










TABLE OF CONTENTS

page

ACKNOWLEDGMENT S............................................................ ....... .............. 4

LIST OF TABLES ..................................................... 7

LIST OF FIGURES .............. ........................................................

AB STRACT ................................................. ....... ....... ........ .............. 12

CHAPTER

1 IN TR O D U C TIO N ..................................................... 14

2 LATE MIOCENE-HOLOCENE MAGNETIC POLARITY STRATIGRAPHY AND
ASTROCHRONOLOGY FROM ODP LEG 198-SHATSKY RISE ..... ..................... 18

Intro du action ..................................................... 18
M eth o d s ....................................................................... 19
M agnetostratigraphic Interpretation ............................................................................. ......... 20
A stro ch ro n o lo g y .................................................................. ...................................... 2 3
D iscu ssio n ..................................................... 2 4
C on clu sion s ..................................................... 2 7

3 INTEGRATED NEOGENE MAGNETIC, CYCLE AND BIO- STRATIGRAPHY
FROM ODP SITE 1208 (SHATSKY RISE, PACIFIC OCEAN) ........ ..............48

Introduction ......... ........ ........ ................. ...... ....... ...... ......... 48
Site Location and Lithology .............. ............ .. .................................. 51
M magnetic Stratigraphy ............................................................................................... 51
C y cle S tratig rap h y ................................................................ .................................... 5 3
C alcareous N annofossils ................................................................................................ 54
Planktonic Foraminifera .................................................................. .... ........ 56
C o n c lu sio n s .......................................................................................... 5 8

4 PALEOINTENSITY-ASSISTED CHRONOSTRATIGRAPHY OF DETRITAL
LAYERS ON THE EIRIK DRIFT (NORTH ATLANTIC) SINCE MARINE ISOTOPE
S T A G E 1 1 .............. .... ............. ................. ........................................................7 5

In tro d u ctio n .............. .... ............. ................. ......................................... 7 5
M methods ..................................... ..... .......... ........... .............. 76
NRM and Normalized Remanence Record ................................................................78
P olarity E excursions ................................................................................................ 79
Relative Paleointensity ................................................................. ... ........ 79
C h ro n o lo g y ........................................................................................................... 8 0
Detrital Layer Stratigraphy.. .............................................................. ............... 81









D iscu ssio n ........................ ................. ................4
C o n clu sio n s ........................ ................. ................7

5 RELATIVE PALEOINTENSITY STACK FOR THE LAST 85 KYR ON A REVISED
GISP CHRONOLOGY, AND ENVIRONMENTAL MAGNETISM OF THE
G A R D A R D R IF T .............. .... ............. ................. ........................................... 10 5

Introdu action ......... ..... ............. ................................. ........................... 10 5
S ite L o catio n s .............. .... ............. ................. ........................ ................. 10 7
M methods .............. ............................................ ................. ......... 108
Directional Magnetic Data ................. ........ ........... ........ 110
Normalized Remanence ................ ............... ...... ............. 111
Stable Isotope Data and Age Models.......................................... 112
Bulk Magnetic and Physical Parameters .................. ............. .......... 112
R elative Paleointensity Stack ..................................................................... 113
Environm mental M agnetism ............................................................................................ 115
C o n c lu sio n s ......................................................................................... 1 1 8

6 RELATIVE GEOMAGNETIC PALEOINTENSITY IN THE GAUSS AND GILBERT
CHRONS FROM IODP SITE U1313 (NORTH ATLANTIC) .............. ............ 136

In tro d u ctio n ......................................................................................... 13 6
M eth o d s ................... ................... ............................3 8
R e su lts ................... ................... ............................3 9
D isc u ssio n .......................................................................................... 14 2

7 ODP SITE 1092 REVISED COMPOSITE DEPTH SECTION HAS IMPLICATIONS
FOR UPPER MIOCENE "CRYPTOCHRONS".................................. 161

Introduction .......................................................... ..................... ........ 161
Revised Composite Depths (rmcd) .............................................................. ............. 162
Implications for Magnetic Stratigraphy ...... ........ ............. .......... ......... 163

8 ASTRONOMICAL AGES FOR MIOCENE POLARITY CHRONS C4AR-C5R (9.3-
11.2 MA), AND FOR THREE EXCURSION CHRONS WITHIN C5N.2N..................... 171

Introduction ............ ......... ......... .................................... .............................. 17 1
Methods and Results .......... ......... ......... ... ............. 173
Comparison with Other Timescales...................................... 175
Excursion Chrons............................ .................. 178

9 CONCLUSIONS AND FUTURE WORK ............................ ................... 189

L IST O F R E F E R E N C E S .................... ......... .................................................... ............. 19 1

B IO G R A PH IC A L SK E T C H ....................................................... ....................................... 204









LIST OF TABLES
Table page

2-1 Latitude, longitude, w ater depth ...................... .... .......... .................... .............. 28

2-2 M agnetostratigraphic age m odel ........................................................ .............. 29

2-3 Comparison of astrochronological age models............... ................................... 30

2-4 A strochronological ages for Leg 198 .................................... .......................... ......... 31

3-1 Depths of reversal boundaries from ODP Site 1208...................................................... 59

3-2 Astronomically calibrated ages for reversal boundaries from ODP Site 1208............... 60

3-3 Nannofossil datum s for ODP Site 1208 ................................................. ....... ...... 61

3-4 Plio-Pleistocene foraminfer datum s ................................................................... 62

3-5 M iocene foram inifer datum s.......................................................... .......................... 63

4-1 Core, latitude, longitude, water depth and base age of the core. ................................ 89

4-2 DC and LDC layer properties in Core MD99-2227 ............. ..... ...................90

4-3 Detrital Layers from other studies considered to be correlative to detrital layers
identified on Eirik drift.............. ... ................ ......... ............... .... .......... 91

5-1 Summary of the cores used in this study and the eleven cores used in the relative
paleointensity stack ................................................................. ... ......... 120

6-1 Depth of polarity chrons from IODP Site U1313 ............................................ 146

6-2 Polarity reversal ages determined at Site U1313 ................ ............................ 147

7-1 Adjusted depths of core tops from ODP site 1092 ..................................................... 166

7-2 Position of the polarity zone boundaries at site 1092........................................... 167

8-1 Astronomical ages from recent timescales compared with those inferred at ODP Site
1 0 9 2 ................... ................... ................... ................................. .. 1 8 1









LIST OF FIGURES


Figure page

2-1 B athym etric m ap of Shatsky R ise........................................................ .. .................. 32

2-2 Representative orthogonal projections of AF demagnetization data. ........................... 33

2-3 Site 1207 component inclination and declination from discrete samples for 0-80
m eters ...............................................................................................3 4

2-4 Site 1207 component inclination and declination from discrete samples for 80-160
m ete rs ...................................... ........................................ ............... 3 5

2-5 Interval sedimentation rates and age versus depth................................................. 36

2-6 Site 1209 component inclination and declination from discrete samples ....................... 37

2-7 Site 1210 component inclination and declination from discrete samples ........................38

2-8 Site 1211 component inclination and declination from discrete samples ........................39

2-9 Site 1212 component inclination and declination from discrete samples ........................40

2-10 Pow er spectra ..................................................................... ......... ........ 41

2-11 The astronomical solution for obliquity compared with tuned L* reflectance data
from Site 1207 ......... ......... .......................................... ........................... 42

2-12 The astronomical solution for obliquity compared with tuned L* reflectance data
from Site 1208 ......... ......... .......................................... ........................... 43

2-13 The astronomical solution for obliquity compared with tuned L* reflectance data
from Site 1209 ......... ......... .......................................... ........................... 44

2-14 The astronomical solution for obliquity compared with tuned L* reflectance data
from Site 1210 ................. ............................................. ......... 45

2-15 The astronomical solution for obliquity compared with tuned L* reflectance data
from Site 12 11 ......... .... ..... ......... ................................ .......................... 46

2-16 C ross-spectral analy sis ...................................... ............ ............... ........................... 47

3-1 Bathymetric map showing the location of Shatsky Rise in the Pacific Ocean ............... 64

3-2 Inclination, declination and MAD values plotted against meters below sea floor .......... 65

3-3 Inclination, declination and M AD values............................................. .. .................. 66









3-4 Inclination, declination and MAD values ..................... ............... ................ 67

3-5 Orthogonal projections showing AF demagnetization data .......................... ......... 68

3-6 Interval sedimentation rates ............................ ...... ......... 69

3-7 R eflectance (L *) data .......... ................ ....................................... ............................ 70

3-8 Plio-Pleistocene planktonic foraminifer and calcareous nannofossil datums................... 71

3-9 Miocene planktonic foraminifer and calcareous nannofossil datums.............................72

3-10 Calcareous nannofossil biostratigraphy...................................................................... 73

3-11 A proposed biostratigraphy for the mid-latitude North Pacific .............. ................... 74

4-1 Location m ap showing the Labrador Sea ................................... ................................. 92

4-2 Component inclination, corrected component declination and maximum angular
dev nation ............................................................................................ 93

4-3 Component inclination, declination and maximum angular deviation (MAD) values
recording Laschamp and Iceland Basin polarity excursions .........................................94

4-4 Anhysteretic susceptibility (kam) plotted against volume susceptibility (k) ..................95

4-5 NRM, ARM, IRM and volume susceptibility..................... ......................... 96

4-6 JPC 19: Relative paleointensity record correlated to that from ODP Site 983................ 97

4-7 JPC 18: Relative paleointensity data correlated to ODP Site 983 ............................98

4-8 JPC 15: Relative paleointensity data correlated to ODP Site 983 ............. ................99

4-9 MD99-2227: Relative paleointensity data correlated to ODP Site 983 ......................... 100

4-10 kam/k and m agnetic susceptibility versus age..................................... ................... 101

4-11 Core MD99-2227: kam/k, magnetic susceptibility, bulk (GRAPE) density ................ 102

4-12 Photographs and X-radiographs of three detrital......................................................... 103

4-13 Hysteresis ratios Mr/Ms plotted versus Her/Hc .......... ................. ................... 104

5-1 Location map for cores analyzed in this study............................ 121

5-2 Correlation of the magnetic susceptibility records .............................................. 122

5-3 Orthogonal projections of alternating field demagnetization data ........................... 123









5-4 Component inclination, declination and maximum angular deviation (MAD) values ... 124

5-5 Plot of anhysteretic susceptibility (karm) versus volume susceptibility (k)..................... 125

5-6 Paleointensity proxies.................... ................................................ ........... ........ ..... 126

5-7 Core JPC13 benthic oxygen isotope record ........................................... ............. 127

5-8 Relative paleointensity records from Cores JPC2, JPC5 correlated to Core JPC13....... 128

5-9 Interval sedimentation rates for Cores JPC2, JPC5 and JPC13 .................................. 129

5-10 Core JPC13: GRA bulk density ............................................... 130

5-11 Anhysteretic susceptibility divided by volume magnetic susceptibility ........................ 131

5-12 Eleven relative paleointensity records from the North Atlantic Ocean........................ 132

5-13 The new relative paleointensity stack ................................... ............................ ........ 133

5-14 Comparison of the EHC06 paleointensity stack to 36C1 flux............... ............. 134

5-15 Comparison of the EHC06 paleointensity stack .......................................................... 135

6-1 Location map for IODP Site U 1313............................................................... 148

6-2 Magnetic polarity stratigraphy from IODP Site U1313 in the 120-200 mcd interval..... 149

6-3 Magnetic polarity stratigraphy from IODP Site U1313 in the 200-280 mcd interval .... 150

6-4 Vector end-point projections of AF demagnetization data........................................... 151

6-5 Interval sedim entation rates ....................................................................................... 152

6-6 G auss C hronozone at Site U 1313 ............. ............. ................................. ............. 153

6-7 The magnetic grain size proxy, anhysteretic susceptibility divided by susceptibility .... 154

6-8 Later part of the Gilbert Chronozone at Site U 1313 .................................................... 155

6-9 Relative paleointensity records from IODP Site U1313 .............................................. 156

6-10 Volume magnetic susceptibility from u-channel samples................................. 157

6-11 Volume magnetic susceptibility from u-channel samples and L* reflectance data
m measured shipboard ................................................................. .... ........ 158

6-12 M ean volum e m agnetic susceptibility ................................... .................................... 159

6-13 Output of a gaussian filter centered on a period of 41 kyr ............................................ 160









7-1 Fe intensity (XRF) data plotted as a five-point moving average.................................. 168

7-2 Inclination of the characteristic magnetization component .................. ................... 169

7-3 Site 1092 ............ .... ............................................................................... .. 170

8-1 Magnetic component inclination for the C4Ar. n-C5r. n interval............. ............. 182

8-2 Oxygen isotope records from the C4An-C5r.ln interval at ODP Site 1092 ................ 183

8-3 Power spectrum generated from the oxygen isotope stack in the depth domain............ 184

8-4 Upper plot shows the correlation of the filtered (filter centered at 0.0244 + 0.0073
kyr1) oxygen isotope stack to the astronomical solution for obliquity......................... 185

8-5 Interval sedimentation rates for the C4Ar. ln-C5r. In interval ............. ................ 186

8-6 Comparison of the age estimates of polarity chrons at ODP Site 1092 .................... 187

8-7 The Site 1092 relative paleointensity record for C5n.2n......................................... 188









Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy

MAGNETIC STRATIGRAPHY AND ENVIRONMENTAL MAGNETISM OF OCEANIC
SEDIMENTS

By

Helen F. Evans

December 2006

Chair: James E. T. Channell
Major: Geology

This dissertation presents the results of chronostratigraphic studies on marine sediment

cores from three Oceans. Using a combination of magnetic stratigraphy, biostratigraphy and

cycle stratigraphy it is possible to produce chronostratigraphies that exceed the resolution of

any individual technique.

In the North Atlantic, environmental magnetic records from Eirik Drift, south of

Greenland, record detrital signals related to the melting of the Greenland and Laurentide Ice

Sheets. The detrital layer stratigraphy has been placed in a paleointensity-assisted

chronostratigraphic template, based on paleointensity and stable isotope data, to enhance

correlation of detrital layers across the North Atlantic region. In the central Atlantic, on Gardar

Drift, correlation of a benthic oxygen isotope record to the Greenland and Vostok Ice cores has

placed cores from the drift on a revised GISP chronology. A stack of relative paleointensity

records was developed and placed on the revised GISP chronology. In marine isotope stage 3, a

benthic isotope record appears to record changes in bottom water temperature that are coeval

with magnetic grain size changes.

IODP Site U1313 from the North Atlantic produced a high-resolution polarity

stratigraphy and relative paleointensity record between 2.5 and 6.0 Ma. This is one of a handful









of paleointensity records for this interval. Cycles in magnetic susceptibility allowed age-

calibration by correlation to a benthic oxygen isotope stack.

Sediment cores from the Pacific Ocean produced excellent magnetic stratigraphies, and

cycles in the sediment allowed astronomic calibration of reversal boundaries. Based on the

correlation of planktonic foraminifer datums to the magnetic stratigraphy at ODP Site 1208, a

new planktonic foraminifer zonation for the northwest Pacific Ocean can be precisely correlated

to polarity chrons and astronomically calibrated ages. Numerous paleomagnetic excursions are

tentatively identified for the first time in Pacific sediments.

Oxygen isotope records from the Late Miocene (9.3-11.2 Ma) at ODP Site 1092 (South

Atlantic) allowed astronomic calibration of ages of reversal boundaries and three polarity

excursions within Chron 5. This is the first time astronomically calibrated ages have been

assigned to these polarity excursion chrons and indicate a duration for the excursions of 3-4 kyrs.









CHAPTER 1
INTRODUCTION

Stratigraphy is a fundamental part of Geology. Earth processes unfold over a great range of

time scales from millions of years to minutes and seconds. One of the challenges in stratigraphy

is to be able to assign dates to events in the geologic record. The geologic timescale is the means

by which we can understand the history of the Earth and magnetic reversal stratigraphy provides

the central framework for the geologic timescale to which other dating techniques

(biostratigraphic, radiometric, orbital) can be tied. This is because magnetic reversals are, on

geologic timescales, globally synchronous, environmentally independent events.

The geomagnetic timescale of Heirtzler et al. (1968) was one of the foundations of the

plate tectonic revolution. They proposed a geomagnetic polarity timescale for the Late

Cretaceous to Recent based on a few long magnetic anomaly profiles. The evolution of the

polarity timescale since 1968 has involved two types of revisions: adjustments of the relative

spacing of some anomalies and calibration of the polarity sequence in time (Cande and Kent,

1992). Over the past forty years the pattern of normal and reversed polarities has been

extensively studied and most of its large-scale features for the past 200 million years are now

well understood (Gradstein et al., 2005).

Classic magnetic polarity reversal stratigraphy lacks the resolution necessary for the

high-resolution (millennial-scale) climate studies being conducted today. This led to the

development of high-resolution cryogenic magnetometers capable of measuring whole-core

samples or u-channel samples. This in turn led to the development of "composite sections" for

marine sediment cores whereby multiple cores were taken at a single site and spliced together to

provide a complete stratigraphic section (Hagelberg et al., 1995).









Changes in the intensity of the Earth's magnetic field occur over much shorter timescales

than polarity reversals. These changes can be measured in sedimentary cores to produce records

of relative geomagnetic paleointensity. This is done by normalizing the natural remanent

magnetization by an artificial remanence to remove intensity changes due to changes in

concentration of magnetic material in the core. Records of relative paleointensity have been

shown to be globally correlative on millennial timescales for the last glacial cycle (Laj et al.

2004).

In attempting to understand the time-depth relationship in marine sediment cores and

therefore understand more about the Earth's climate and evolution my work covers three Oceans,

the South Atlantic, the North Atlantic and the Pacific. Below is a summary of the work presented

in this dissertation. The nature of this work is collaborative and, as such, data provided by my

colleagues is included in this dissertation. Their contribution is acknowledged and clearly

detailed in the following summary.

In Chapter 2 magnetostratigraphic and cyclostratigraphic results are presented for the 0-

12 Ma interval from sites drilled during ODP Leg 198 to Shatsky Rise. Cyclic alternations in the

percentage of calcium carbonate, as shown by color reflectance data and gamma ray attenuation

bulk density measured on the sediments, allowed astronomic calibration of the magnetic

stratigraphy from six ODP Sites. This chapter was published in the Scientific Results Volume for

Ocean Drilling Program (ODP) Leg 198 (Evans et al., 2005). Chapter 3 is a continuation of this

work and has produced an integrated magneto- bio- and cyclostratigraphy from ODP Site 1208

for the 1-12 Ma interval. Biostratigraphic data included in this chapter were provided by

Nicholas Venti, Mark Leckie (U. Massachusetts, foraminifer) and Paul Bown (University

College London, nannofossils).









In Chapters 4 and 5, I used sedimentary relative paleointensity records to correlate

between cores collected on drift deposits in the North Atlantic. In Chapter 4, I present a study of

sediments from the Eirik drift for the 0-400 ka interval. Detrital layers identified within four

cores are placed in a paleointensity assisted chronostratigraphic framework. Environmental

magnetic records from climatically sensitive regions such as the North Atlantic can provide

information about changes in the strength of bottom currents and ice sheet dynamics both of

which are climatically sensitive. Oxygen isotope data used in this chapter were provided by Jim

Wright and Lauren Nietzke (Rutgers University) and Claude Hillaire-Marcel (GEOTOP) (Core

MD99-2227). This chapter is under review in the journal Geophysics, Geochemistry and

Geosystems. In Chapter 5 cores from the Gardar Drift provide records of changes in magnetic

grain size over glacial/interglacial and stadial/interstadial cycles for the last 130 ka. These

changes are interpreted as changes in the speed of bottom currents forming the drift deposits over

glacial/interglacial cycles and stadial/interstadial cycles. David Hodell (UF) provided oxygen

isotope data in Chapter 5.

In Chapter 6 a paleomagnetic study of IODP Site U1313 from the North Atlantic is

presented. The magnetic stratigraphy spans the interval from 2.5-6.3 Ma including the Gauss and

Gilbert chronozones. A relative paleointensity record for the Gauss and Gilbert chrons, is one of

only a handful of such records for this time interval. Cycles in magnetic susceptibility have

allowed astronomic calibration of the ages of reversal boundaries.

In 2001, my MS thesis consisted of a paleomagnetic study of ODP Site 1092 from the

South Atlantic. Chapter 7 presents a revision of the composite depth scale from ODP Site 1092.

X-Ray fluorescence (XRF) scanning data were provided by Thomas Westerhold (University

Bremen). This chapter was published in Geophysical Journal International (Evans et al. 2004).









In Chapter 8 we use cyclic alternations in a stack of three oxygen isotope records (Paulsen et al.,

in press) from ODP Site 1092 in the South Atlantic to astronomically tune the magnetic

stratigraphy from 9.3-11.2 Ma. This includes the long normal polarity chron C5n.2n and three

short reverse polarity intervals within it identified by Evans and Channell (2003). It also includes

a critical age tie-point from the Cande and Kent (1995) Geomagnetic Polarity Timescale (GPTS)

at the base of C5n.2n. This chapter is under review at Earth and Planetary Science Letters.









CHAPTER 2
LATE MIOCENE-HOLOCENE MAGNETIC POLARITY STRATIGRAPHY AND
ASTROCHRONOLOGY FROM ODP LEG 198-SHATSKY RISE

Introduction

Shatsky Rise is a medium-sized large igneous province in the west-Central Pacific Ocean

(Figure 2-1) and is possibly the oldest existing oceanic plateau. The rise consists of three

prominent topographic highs. Sites 1209, 1210, 1211 and 1212 were cored on the Southern High

(Bralower, Premoli Silva, Malone et al., 2002). Eight sites on the Southern High of the rise were

drilled during Deep Sea Drilling Project (DSDP) and earlier Ocean Drilling Program (ODP) legs

(Sites 47, 48, 49, 50, 305, 306, 577, and 810). Of these, ODP Sites 577 and 810 provided

interpretable Neogene magnetic stratigraphies.

Sites 1207 and 1208, from the Northern and Central Highs, provided unexpectedly

expanded late Miocene (12.5 Ma) to Holocene sequences. These locations had not been cored

during previous DSDP/ODP expeditions. The initial age model for all of the sites was based on

correlation of the sequence of polarity zones to the geomagnetic polarity timescale (GPTS)

(Cande and Kent, 1992, 1995). Mean sedimentation rates at the five sites vary from 1- to 4

cm/k.y. Latitude and longitude of the sites and basal ages of the Neogene sediments are given in

Table 2-1. Neogene sediments at the sites consisted mostly of light gray to pale orange

nannofossil oozes with varying amounts of clay, radiolarians, and diatoms. Magnetic

susceptibility is low (< 2 x10-5 SI) at all the sites and shows a decreasing trend from the

Quaternary to the late Miocene. Composite sections were constructed shipboard for four of the

sites (1209, 1210, 1211, and 1212) using multi-sensor track (MST) data including magnetic

susceptibility, gamma ray attenuation (GRA) bulk density, and reflectance data. Sites 1207 and

1208 were not double-cored, and depths at these sites are in meters below sea floor (mbsf). The









magnetic stratigraphy from the six sites (1207, 1208, 1209, 1210, 1211, and 1212), was based on

shipboard pass-through magnetometer measurements and discrete samples measured post-cruise.

Sediments from five of the sites (1207, 1208, 1209, 1210, and 1211) showed a prominent

cyclicity in reflectance data for parts of the sections, and this is the basis for the construction of

an astronomically tuned age model for the 0- to 8-Ma interval. The astronomically calibrated

polarity timescale has been well established for the 0- to 6-Ma interval (Shackleton et al., 1990,

1995; Hilgen 1991a, 1991b). Hilgen (1991a, 1991b) produced his astronomically calibrated

polarity timescale for the 2- to 5.23-Ma interval using sapropel occurrences and carbonate

content in Mediterranean sections. These polarity chron ages were incorporated into the GPTS of

Cande and Kent (1995).

In this study we produced an astronomically calibrated magnetic reversal stratigraphy for

the 0- to 8-Ma interval. This is in good agreement with Hilgen (1991a, 1991b) and Shackleton et

al., (1995) in the 0- to 6-Ma interval. In the 6-to 8-Ma interval, polarity chron ages are in better

agreement with the Shackleton et al. (1995) timescale, differing by up to -200 k.y. from that of

Hilgen et al. (1995) and the ATNTS 2004 of Lourens et al. (2004). This chapter was published in

the Scientific Results Volume for ODP Leg 198 (Evans et al., 2005).

Methods

Two types of paleomagnetic measurements were made on sediments collected during ODP

Leg 198; pass-through measurements on half-cores and discrete sample measurements. Discrete

sample cubes (2cm x 2cm) were collected during Leg 198 to augment measurements using the

shipboard pass-through magnetometer. Shipboard measurements on half-cores were made at 5-

cm intervals. A total of 747 discrete samples were taken at 50-cm intervals. Discrete samples

were collected from the center of the half-cores to avoid deformation at the outer edges of the

core. Magnetic measurements on the cubes were performed in the magnetically shielded room at









the University of Florida using a 2G-Enterprises cryogenic magnetometer. The samples were

step-wise alternating-field (AF) demagnetized using a D-Tech D2000 AF demagnetizer.

Magnetization component directions were determined using the method of Kirschvink (1980),

applied to the 20- to 60 mT peak field demagnetization interval.

The astrochronology developed for Sites 1207, 1208, 1209, 1210, and 1211 was based on

cycles seen in reflectance data (L*) measured shipboard on a purpose-built track. Reflectance of

visible light from soft sediment cores was measured using a spectrophotometer at 2.5-cm

intervals and provided a high-resolution record of color variations for visible wavelengths (400-

700 nm). L* reflectance represents "lightness" of the sediment which is usually controlled by

changes in percent carbonate.

The initial age model for each site was based on correlation of the polarity zone sequence

to the timescale of Cande and Kent (1995). Power spectra using the Blackman-Tukey method

with a Bartlett window from the Analyseries software of Paillard et al. (1996) indicate the

presence of obliquity and eccentricity peaks. The reflectance data were then tuned to the

astronomic solutions for obliquity from Laskar et al. (1993). This allowed astronomically

calibrated ages to be assigned to the polarity reversal boundaries at Sites 1207, 1208, 1209, 1210

and 1211. Site 1212 was not included in the astrochronology, as it contains a hiatus at 4- to 5-

Ma.

Magnetostratigraphic Interpretation

Site 1207 is the only site that has been drilled on the Northern High of Shatsky Rise. The

sequence of sediment recovered was mostly Neogene in age (0-163.8 mbsf) underlain by

Campanian and older oozes and cherts. The sediment consists of nannofossil ooze with diatoms,

radiolarians, and clay in varying amounts (Bralower, Premoli Silva, Malone et al., 2002). The

samples taken for paleomagnetic analysis were AF demagnetized in 5-mT steps up to either 50,









60, or 70 mT, depending on the intensity of the natural remanent magnetization (NRM). Less

than 10% of the NRM remains after demagnetization at these peak fields, indicating a low-

coercivity remanence carrier, most likely magnetite. Orthogonal projections of demagnetization

data (Figure 2-2) show well-defined components for most of the Neogene section after removal

of the steep drilling related overprint at peak AF fields of 20 mT. Maximum angular deviation

(MAD) values are low for most of the section (< 100), indicating well-defined characteristic

magnetization components; however, some intervals, particularly the interval between 50-60

mbsf (Figure 2-3), have slightly higher MAD values and less well-defined components. The

interpretation of the magnetic stratigraphy from shipboard and discrete sample data can be

accomplished by polarity zone pattern fit to the GPTS (Cande and Kent, 1992, 1995) (Table 2-2).

This pattern fit is satisfactory to the base of Subchron C5An. in (Figures 2-3, 2-4). Below the

polarity zone equivalent to Subchron C5An. In, recovery was intermittent and biostratigraphy

indicates a hiatus with Campanian age sediments below (Bralower, Premoli Silva, Malone et al.,

2002). Sedimentation rates average 1-2 cm/k.y. throughout the section with some slightly higher

(3-4 cm/k.y.) rates in the late Pliocene and late Miocene (Figure 2-5A). Component declination

has been corrected for each core using Tensor orientation data measured shipboard. The mean

inclination in normal polarity zones for the Site is 57.80, close to the expected inclination of 560

for a geocentric axial dipole at this site; however, reversed polarity intervals have a mean

inclination of -51.1, shallower than expected. This can be attributed to shallowing of reversed

polarity directions by the steep downward-directed drilling overprint, shown clearly in the

orthogonal projections (Figure 2-2A).

Sites 1209, 1210, 1211, and 1212 are located on the southern high of Shatsky Rise

(Figure 2-1). Multiple holes were drilled at each site and composite sections were constructed









using shipboard MST data. Discrete sample cubes were only collected from Holes 1209A,

1210A, 1211A, and 1212A. The shipboard data from the pass-through magnetometer are

consistent between the different holes at each site and confirms the interpretation of the magnetic

stratigraphy (see Shipboard Scientific Party, 2002).

As for Site 1207, orthogonal projections from discrete sample data show two components:-

a steep downward drilling related overprint and well-defined characteristic components (Figure

2-2 B, C, D, E). In most cases the drilling related overprint was easily removed in peak AF fields

of 10-20 mT. Little of the natural remanent magnetization remained at peak fields of 60 mT.

MAD values are generally <50 throughout the sections. The expected inclination for the

Southern Rise is 51; again, all the sites show slightly steeper than expected inclinations in

normal polarity zones and shallower than expected inclination in reversed polarity zones. The

magnetostratigraphic age models indicate mean sedimentation rates between 1- and 3 cm/k.y. for

most of the Neogene (Figure 2-5 B, C, D, E).

The polarity interpretation at Sites 1209, 1210, and 1211 is unambiguous back to Subchron

C3Bn (Table 2-2) (Figures 2-6, 2-7, 2-8). Below this level, interpretation becomes difficult due

to decreasing sedimentation rates leading to a hiatus recognized at all sites between the upper

Miocene, and Oligocene and older sequences. At Site 1212, a hiatus accounts for the interval

between 4 and 5 Ma (Chron C3), and the polarity interpretation can be accomplished to

Subchron C4n.2n (Figure 2-9). This interpretation of the sequence of polarity zones is confirmed

by the shipboard biostratigraphy. The interpretation of the polarity stratigraphy was carried out

using data measured shipboard augmented with discrete sample cubes. When the

magnetostratigraphic data were placed on the composite depth scale, the reversal boundaries

were found to be consistent between holes, indicating that there is very little error in the depths









of polarity zone boundaries or in composite depth calculations. The magnetic measurements

made shipboard do include a small amount of error due to the response function of the shipboard

magnetometer. The response function of the wide-access magnetometer used to measure half-

cores is -10 cm, resulting in a cm-scale uncertainty in the placement of the reversal boundaries.

Site 1208 is located on the Central High of Shatsky Rise and also provided an expanded

late Miocene to Holocene section. The magnetic stratigraphy from Site 1208 will be presented in

Chapter 3.

Astrochronology

Cycles were visually identifiable in L* reflectance data from all six of the sites in this

study. For Sites 1209, 1210, and 1211, we worked with spliced composite records rather than

data from a single hole. Reflectance data were initially placed on the magnetostratigraphic age

model based on the polarity timescale of Cande and Kent (1995). Power spectra for untuned

sections of reflectance data placed on this age model consistently show a concentration of power

at orbital frequencies, particularly around the 41 k.y. obliquity cycle (Figure 2-10).

The reflectance records were then tuned to the astronomical solution for obliquity from

Laskar et al. (1993), as this was the most visually identifiable cycle in the reflectance data and

the power spectra for different time intervals in all the sites showed a concentration of power at

the obliquity frequency (Figure 2-10). In constructing the astrochronological age model, we

assume that there was no phase lag between the orbital forcing and the response. For

convenience, the reflectance data were broken up into 1 Myr intervals when compared to the

astronomical solution and each site was tuned independently. Cycles were readily apparent in the

reflectance data for all sites, and tuning of the record required a minimum of adjustment of peaks

in the reflectance data to the astronomical solution (Figures 2-11, 2-12, 2-13, 2-14).

Astronomically tuned ages were calculated for polarity reversals in the 1 to 8-Ma interval at Site









1207 (Table 2-3). At Site 1209, tuning was performed in the 1 to 7-Ma interval and at Sites 1210

and 1211 in the 1 to 5-Ma interval. Site 1208 has also provided an astrochronological age model

for the 1 to 6-Ma interval (Figure 2-12) and is included in Table 3. The tuned age models are

compared to each other (Table 2-3) and are compared with other recently published

astrochronologies for this time period (Table 2-4). The output of a band-pass filter centered on

41 k.y. is shown below the astronomical solution for obliquity and the raw reflectance data in

Figures 2-11, 2-12, 2-13, 2-14, and 2-15.

To test the validity of the timescale we used cross-spectral analysis performed using the

Blackman-Tukey method and Analyseries software (Paillard et al., 1996). Coherence between

the reflectance data and the astronomical solution for obliquity was significant at all the sites,

although the coherence values depend on which time interval is being examined. At Site 1207

coherence was 0.8 for the 1.2 to 1.8-Ma and 6.2 to 6.8-Ma intervals (Figure 2-16A). The

coherence values at Site 1208 were > 0.8 for the entire 1 to 6-Ma interval. Sites 1209, 1210, and

1211 also showed coherence values between 0.8 and 1 (Figure 2-16C, 2-16D, 2-16E).

Discussion

Comparison of the tuned ages for polarity reversal boundaries at the five sites in the 1.5

to 2-Ma interval showed that polarity chron ages are in good agreement. For other time intervals

there are some significant differences (more than an obliquity cycle) between sites (Table 2-3).

Intervals with enhanced 41 k.y. power in reflectance data are considered more reliable (italics in

Table 2-3). Site 1208 showed the strongest cyclicity, with Site 1207 also showing a clear signal

in some intervals particularly the 2.1 to 2.7-Ma and 4.5 to 5-Ma intervals.

During ODP Leg 138 to the eastern equatorial Pacific, 11 sites were drilled and most of

them showed a prominent cyclicity in GRA density. Shackleton et al. (1995) used these cycles in

GRA bulk density records to produce an orbitally-tuned age model for the 0 to 12.5-Ma interval.









They worked entirely in the time domain comparing smoothed GRA bulk density records with

the target record of summer insolation at 650N. In their tuning they assumed that no phase lag

existed between insolation and GRA bulk density controlled by proportion of Si02 and CaCO3

(high density), high carbonate content being associated with high Northern Hemisphere

insolation. Age control points were added to the data to align prominent groups of density

maxima. The records were broken into 0.8-m.y. intervals for convenient viewing. Each site was

tuned independently over the chosen time interval. Shackleton et al. (1995) found that some

intervals in these records were more easily tuned than others, similar to results from Leg 198.

Shackleton et al. (1995) noted that it was difficult to tune the 0- to 1-Ma interval, which was also

the case at four of the Leg 198 Sites (1208, 1209, 1210, and 1211). The 1- to 2-Ma interval for

the Leg 138 sites carries a clear 41 k.y. obliquity cycle. For Leg 198 sites, the 1.2- to 1.6-Ma

interval also carries a very clear obliquity cycle (Figures 2-11, 2-12, 2-13, 2-14, 2-15). In the 2.4-

to 2.6-Ma interval, a very strong obliquity cycle was observed at Site 846 (Leg 138), and this

same interval also carries a strong 41 k.y. signal at Sites 1209, 1210, and 1211. Comparison

between the Site 1207 age model and ages from Shackleton et al. (1995) indicate consistency for

the 1-to 8-Ma time interval (Table 2-4).

Hilgen et al. (1995) developed an astronomical timescale for the interval from 3- to 9.7-Ma

using lithologic cyclicity seen in sedimentary sections in the Mediterranean. These sections

comprise open marine sediments that alternate between carbonate-rich and carbonate-poor marls

or homogeneous marls and sapropels. The individual sapropels were related to precession

minima, and the clusters of sapropels to the 400-k.y. eccentricity cycles. In tuning the section,

the target curve used was the 65N summer insolation curve. To obtain an astronomical age for

the youngest polarity reversal in the sequence, Hilgen et al. (1995) took the Shackleton et al.









(1995) age for the onset of Subchron C3An.2n of 6.576 Ma. They then matched the lithologic

cycles in the section to the astronomical solution using the correlation of sapropel clusters to

eccentricity. The age of the calibration point (6.576 Ma) had to be adjusted to 100 k.y. older to

establish a consistent correlation between sapropel clusters and eccentricity maxima. The ages

from Hilgen et al. (1995) differ significantly with those from Leg 198 in the 6-to 8-Ma interval

(Table 4). At the top of Subchron C3Bn the difference is more than 200 k.y. In the interval from

7.2- to 8.1-Ma, the difference is 100 k.y. which is the amount of adjustment of the 6.576-Ma

tie point used by Hilgen et al. (1995) for the age of the youngest polarity reversal in their section.

ODP Site 926 on the Ceara Rise also produced an orbitally tuned timescale from 5- to 14-

Ma (Shackleton and Crowhurst, 1997). This timescale cannot be directly compared with the Leg

198 timescale because of a lack of polarity reversals at Site 926. Backman and Raffi (1997) used

the cyclostratigraphic age model from Site 926 to calibrate ages of the calcareous nannofossil

datums for the late Miocene. These ages were then compared with the biomagnetochronology

from Site 853 (ODP Leg 138). The center of the peak in abundance of transitional morphotypes

of Triquetrorhabdulus rugosus at Site 853 occurred 120-130 k.y. after the corresponding peak at

Site 926. The age estimates of Hilgen et al. (1995) were then applied to the Site 853 data and the

peak center was found to coincide at Sites 853 and 926. Therefore, Backman and Raffi (1997)

considered that the Hilgen et al. (1995) ages are more reliable in this interval than the ages of

Shackleton et al. (1995).

Lourens et al. (2004) have recalibrated the Miocene astronomic timescales of Shackleton

and Crowhurst (1997) and Hilgen et al. (1995) using the astronomic solution of Laskar et al.

(2004). For the last 13 Ma the returning resulted in almost negligible changes in the ages of

reversal boundaries (Lourens et al., 2004). For the 6- to 8- Ma interval the ATNTS2004 is in









close agreement with that of Hilgen et al (1995) and therefore differs significantly with the

results of this study.

Conclusions

Five sites from Shatsky Rise have produced high-quality magnetic stratigraphies from the

late Miocene to Holocene. Cycles identified in reflectance data from Sites 1207, 1208, 1209,

1210, and 1211 have allowed astronomic calibration of the polarity reversal sequence from -8

Ma to present. The assumption that there is no phase lag between sedimentary cyclicity and the

astronomical parameters allowed the cycles to be tuned to the astronomical solution for

obliquity. Cross-spectral analysis on the tuned age model indicated high coherence between the

astronomic solution and the reflectance data and confirms the reliability of the tuning. The age

model has been compared with other published astrochronologies and is found to be in good

agreement with Hilgen (1991a, 1991b) (and, therefore, Cande and Kent [1995]) in the 1-to 6-Ma

interval. In the 6-to 8-Ma interval the age model differs significantly from that of Lourens et al.

(in press) and Hilgen et al. (1995) from the Mediterranean. It is in better agreement with the

ODP Leg 138 timescale of Shackleton et al. (1995) from the Pacific Ocean.











Table 2-1. Latitude, longitude, water depth, the oldest Neogene magnetic polarity chron
identified, and the basal age of the Neogene section.


Latitude

3747.4287' N
32 39.1001'N
32 13.4123'N
32 0.1300'N
32 26.9000'N


Longitude

16245.0530'E
15830.3560'E
15815.5618'E
15750.9999'E
15742.7016'E


Water Basal Chron Basal Age
depth (Ma)
3100m C5An2n 12.184
2387m C3Bn 7.091
2573m C3Bn 7.091
2907m C3Bn 7.091
2682m C4n.2n 8.072


Site

1207
1209
1210
1211
1212













Table 2-2. Magnetostratigraphic age model for Sites 1207, 1209, 1210, 1211 and 1212. Polarity
chron labels are according to Cande and Kent (1992, 1995). Ages of chrons are from

Cande and Kent (1995). Depths are in meters below sea floor (mbsf) for Site 1207
and meters composite depth (mcd) for Site 1209, 1210, 1211 and 1212.


Chron
Cln
base
Clr.1n
base
C2n
base
C2r. ln
base
C2An. in
base
C2An.2n
base
C2An.3n
base
C3n.ln
base
C3n.2n
base
C3n.3n
base
C3n.4n
base
C3An.ln
base
C3An.2n
base
C3Bn
base
C3Br.n n
base
C3Br.2n
base
C4n.ln
base
C4n.2n
base
C4r. ln
base
C4An
base
C4Ar. In
base
C4Ar.2n
base
C5n.ln
base
C5n.2n
base
C5r.ln
base
C5r.2n
base
C5An.ln
base
C5An.2n
base


Ma (CK95)
0.00
0.780
0.990
1.070
1.770
1.950
2.197
2.229
2.581
3.040
3.110
3.220
3.330
3.580
4.180
4.290
4.480
4.620
4.800
4.890
4.980
5.230
5.894
6.137
6.269
6.567
6.935
7.091
7.135
7.170
7.341
7.375
7.432
7.562
7.650
8.072
8.225
8.257
8.699
9.025
9.23
9.308
9.580
9.642
9.740
9.880
9.920
10.949
11.052
11.099
11.476
11.531
11.935
12.078
12.184
12.401


1207 (mbsf)
0.00
12.35
16.26
16.77
24.38
28.40
29.73
30.25
43.13
51.77
53.25
56.79
58.77
66.91
80.23
83.34
87.19
90.46
92.39
94.32
96.84
99.95
105.73
106.77
109.29
114.18
116.56
120.41


1209 (mcd)
0.00
11.28
13.32
14.22
25.28
28.21


37.69
49.43


52.34
58.03
66.22
68.23


73.24
74.08
75.59
78.76
82.94
84.95
86.12
90.13
93.81
96.15


1210 (mcd)
0.00
14.89
18.07
19.71
32.03
34.70
37.68
38.09
46.51
56.88
58.52
60.37
61.81
67.35
75.36
77.62
80.90
82.34
83.78
85.42
86.45
91.17
94.05
95.69
97.02
99.12
100.35
101.46


1211 (mcd)
0.00
8.00
9.550
10.27
16.74
18.38
23.70
30.08
30.90
32.34
33.98
37.37
41.17
42.51
43.94
44.66
46.92
49.28
50.72
51.70
52.69
53.80
54.29
55.15


123.08
123.53
125.16
126.05
126.34
129.01
130.79
132.27
134.50
136.72
137.76
138.35
140.28
140.72
141.32
142.36
142.65
151.40
153.62
154.07
155.11
155.40
157.81
160.77
161.76


1212 (mcd)
0.00
11.95
14.12
14.98
23.62
25.78
26.95
27.78
32.61
39.00
39.81
41.67
43.00
48.68










54.44
56.17
58.31
59.14
59.88
61.03
61.60
63.58
64.57
65.14
65.39
66.95
67.37
70.00











Table 2-3. Comparison of astrochronological age models for sites 1207, 1208, 1209, 1210 and
1211. Italics indicate the most reliable ages in intervals where the cyclicity in
reflectance is best defined. In italics and brackets are the differences between tuned
ages and those of Cande and Kent (1995).


Chron Ka
(CK95)
(Hilgen
1991a,b)
Cln 0
Clr.lr 780
Clr.ln 990
Clr.2r 1070
C2n 1770
C2r. r 1950
C2r.ln 2140
C2r.2r 2150
C2An.ln 2581
C2An.lr 3040
C2An.2n 3110
C2An.2r 3220
C2An.3n 3330
C2Ar 3580
C3n.ln 4180
C3n.lr 4290
C3n.2n 4480
C3n.2r 4620
C3n.3n 4800
C3n.3r 4890
C3n.4n 4980
C3r 5230
C3An.ln 5894
C3An.lr 6137
C3An.2n 6269
C3Ar 6567
C3Bn 6935
C3Br.lr 7091
C3Br.ln 7135
C3Br.2r 7170
C3Br.2n 7341
C3Br.3r 7375
C4n. n 7432
C4n. r 7562
C4n.2n 7650
C4r. r 8072


Site 1207
Ka
(difference)
0
776.7 (-3.3)
992.8 (2.8)
1089.4 (19.4)
1786.4 (16.4)
1954.2 (4.2)
2095.7 (-44.3)
2112.0 (-38)
2620.5 (39.5)
3042.5 (2.5)
3118.0(8)
3236.5 (16.5)
3354.5 (24.5)
3593.3 (13.3)
4154.0 (-26)
4262.5 (-27.5)
4489.8 (9.8)
4637.0(17)
4760.5 (-39.5)
4857.3 (-32.7)
4972.5 (-7.5)
5245.4 (15.4)
5886.0 (8)
6143.0 (6)
6241.5 (-27.5)
6526.2 (-40.8)
6878.0 (-57)
7095.8 (4.8)


75-3 2 (8.2)
7388.3 (13.3)
7453.5 (3.5)
7540.9 (-21.1)
7634.1 (15.9)
8038.0 (-34)


Site 1208
Ka
(difference)




1073.9 (3.9)
1776.2 (6.2)
1948.7 (-1.3)
2133.5 (-6.5)
2170.4 (20.4)
2564.7 (-16.3)
3045.2 (5.2)
3105.8 (-4.2)
3229.8 (9.8)
3340.9 (10.9)
3599.6 (19.6)
4190.9 (10.9)
4351.9 (61.9)
4523.6 (43.6)
4683.8 (63.8)
41'*,. ) (6.9)
41i '9 (-9.1)
4991.8 (11.8)
5201.2 (-28.8)
5952.7 (58.7)


Site 1209
Ka
(difference)




1069.4 (-0.6)
1770.0 (0)
1975.4 (25.4)


2550.3 (-30. 7)
3032.0 (-8)


3361.4 (31.4)
3648.8 (68.8)
4172.5 (-7.5)
4305.9 (43.4)


4809.0 (9)
4880.9 (-9.1)
4981.5 (1.5)
5240.2 (10.2)
5915.8 (21.8)
6073.9 (36.9)
6318.3 (49.3)
6548.3 (-18. 7)
6971.3 (35.3)
7027.7 (-63.3}


Site 1210
Ka
(difference)





1777.8 (7.8)
1972.2 (22.2)


2642.7 (61.7)
3032.9 (-7.1)
3114.9 (4.9)
3248.5 (~\ 5)
3340.5 (10.5)
3597.5 (17.5)
4182.8 (2.8)
4305.9 (15.9)
4501.0 (21)
4665.3 (45.3)
4798.8 (-1.2)
4891.2 (1.2)
4973.3 (-6.7)


Site 1211
Ka
(difference)





1777.8 (7.8)
1972.2 (22.2)


2536.1 (-44.9)
3022.2 (-17.8)
3110.9 (0.9)
3242.3 (22.3)
3352.8 (22.8)
3644.4 (64.4)
4169.4 (-10.6)
4305.6 (15.6)
4457.9 (-22.1)
4589.3 (-30.7)


4950.7 (-29.3)









Table 2-4. Astrochronological ages for Leg 198 compared to ages Hilgen (1991a, 1991b), Hilgen
et al. (1995) and Shackleton et al, (1995). In italics and brackets are the differences
between Leg 198 tuned ages and Hilgen et al. (1995) and Shackleton et al. (1995).


Chron


Cln
base
Clr.ln
base
C2n
base
C2r. ln
base
C2An. in
base
C2An.2n
base
C2An.3n
base
C3n.ln
base
C3n.2n
base
C3n.3n
base
C3n.4n
base
C3An. in
base
C3An.2n
base
C3Bn
base
C3Br.ln
base
C3Br.2n
base
C4n. ln
base
C4n.2n
base


Ka (CK95)
Hilgen
(1991a,b)

0
780
990
1070
1770
1950
2140
2150
2581
3040
3110
3220
3330
3580
4180
4290
4480
4620
4800
4890
4980
5230
5894
6137
6269
6567
6935
7091
7135
7170
7341
7375
7432
7562
7650
8072


Leg 198





776.7
992.8
1089.4
1786.4
1954.2
2133.5
2170.4
2564.7
3042.5
3118.0
3236.5
3354.5
3593.3
4190.9
4351.9
4523.6
4683.8
4806.9
4880.9
4972.5
5201.2
5952.7
6143.0
6241.5
6526.2
6878.0
7095.8


7348.2
7388.3
7453.5
7540.9
7634.1
8038.0


Shackleton
et al. (1995)
(difference
to 198)











3046 (3.5)
3131 (13)
3233 (-3.5)
3331 (-23.5)
3594 (.7)
4199 (8.1)
4316 (-35.9)
4479 (-44.6)
4623 (-60.8)
4781 (-25.9)
4878 (-2.9)
4977 (4.5)
5232 (30.8)
5875 (-77.7)
6122 (-21)
6256 (14.5)
6555
6919 (4)
7072 (-23.8)





7406 (-47.5)
7533 (-7.9)
7618 (-16.1)
8027 (-11)


Hilgen et al.
(1995a)
(difference
to 198)






























6677 (150.8)
7101 (223)
7210 (114.2)
7256
7301
7455 (106.8)
7492 (103.7)
7532 (78.5)
7644 (103.1)
7697 (62.9)
8109 (71)
































Figure 2-1. Bathymetric map of Shatsky Rise showing the location of sites drilled during ODP
Leg 198.













S/U N/Up




W F
198-1207A-2H.2
mb.r= 7 07


L"_lreal =mml
HbI-a 17 H r- t = 50 mT
HL-treaat 0 m
S1,1n -07 30 5
5 n~ Hi~ tret = 50 mT n 5. I1n
Lui rc $/Pn


Lo Ireat = 0 T
Hi treal= 60 n







5/Un
C) N/Up



I -121(1A-H-
mrd = 0.48
Lo treat = OmT
HI treat 60 TI




'U,
5;;


19S1209A 2H
mcd I 55
II tIreat = 0 m
lli trial = t0 j


)A-2H
- 9.,5
=01
601


mcd= 102 55 S/Dn -
Hi-treat= r60 mT

198-l211A-15H-I
mcd = 120 0
Li-treat = 0 inT
Hi-(reat 60 mT


N/UP





'T <





: : ',-- E

"'UP




-3 I -121
iT Hi tea


i I
Q |


1212A 8H 2 1N14
T-rta m aT
H ll Nr \mlrT
s, S I1,


Figure 2-2. Representative orthogonal projections of AF demagnetization data from (A) Site

1207, (B) Site 1209, (C) Site 1210, (D) Site 1211 and (E) Site 1212. Low AF

demagnetization treatment and the high treatment are given, as is mbsf or mcd of the

sample. Open circles represent the vector end-point projection on the vertical plane,

while closed circles represent the vector endpoint projection on the horizontal plane.


N/Up



L-itfea = 0 05







Sin


IA- 3H,
at =0 inT
I 6 in


N/Up





-I--I
ii


.tp
i ,'


V 1212A-KH-I

Hi trc l liniT


s
Hcr;
n


Ifvn












Site 1207


Chrons


10 -t -




I0 r -
20











40
_. -- .



-t4

B _
50

--- __ _^^



60





70



80

80 I


Declination (0)


S tu ou 0 5 10 15 2025
Inclination (0)
MAD (0)


Figure 2-3. Site 1207 component inclination and declination from discrete samples (open
squares) for 0-80 meters. Inclination and rotated declination from the shipboard pass-
through magnetometer after AF demagnetization at peak fields of 20 mT (gray line).
Chrons are labeled according to Cande and Kent (1992). Black indicates normal
polarity, white reversed polarity. Also shown are the MAD values calculated for
discrete sample data (after Kirschvink, 1980).












Site 1207


80 I j -



--


II. _--I










-

110 -- --- ---
110





120






130



7-J


140





150 I I






160 I i


0 50 100 150 200 250 300 350-80
Declination (0)


Chrons


n--

A-I-

-n


i











~i


%i
-





.= -- ; *- -





~ --i-i
-==3'-



c--------


C3n.2n


C3n.3n


C3n.4n


C3r


C3An.In


C3An.2n


C3Ar

C3Bn

C3Br
C4n.,n

C4n.2n

C4r

C4An

C4Ar

C5n.In


C5n.2n
cryptochron
C5n.2n-3 ?

C5r


C5An.ln


0 40 80
Inclination (0)


u
rr;
o

r





',





~

i'

e




~3
rr=
~20


0 5 10 15 2025
MAD (o)


Figure 2-4. Site 1207 component inclination and declination from discrete samples (open
squares) for 80-160 meters. Inclination and rotated declination from the shipboard
pass-through magnetometer after AF demagnetization at peak fields of 20 mT (gray
line). Chrons are labeled according to Cande and Kent (1992). Black indicates normal
polarity, white reversed polarity. Also shown are the MAD values calculated for
discrete sample data (after Kirschvink, 1980).


V-



-c
C
















20-

40




80


c)

140

160
0 2
























e) o
20


40

E60


80










0) 0 _


1207A age model
I I


6 8 10 12
Age (Ma)


1210 age model


3 4 5 6
Age (Ma)


60 b)





40





to d

0 Io-
0


1209 Age model
















S 2 3 4 5 6 7 8
Age (Ma)


1211A age model


50


7 8


2 3


4
Age (Ma)


1212age model


4
Age (Ma)


Figure 2-5. Interval sedimentation rates and age versus depth for the initial age model at a) Site
1207, b) Site 1209, c) Site 1210, d) Site 1211 and e) Site 1212.


30





20
25 |

















20





a
20



1s

S-


iS











Hole 1209A


I I r


20
20 _


40 ,






E -
S601
C,
C)


In-


Ic I I


Ii


-7



0 50 100 150 200 250 300 350-80
Corrected Declination (o)


-40 0 40
Inclination (o)


0 5 10 15 20
MAD (o)


Figure 2-6. Site 1209 component inclination and declination from discrete samples (open
squares). Inclination and rotated declination from the shipboard pass-through
magnetometer after AF demagnetization at peak fields of 20 mT (gray line). Chrons
are labeled according to Cande and Kent (1992). Black indicates normal polarity,
white reverse polarity. Also shown are the MAD values calculated for discrete sample
data (after Kirschvink, 1980).


Chrons


__ jl













Hole 1210A


_
S- I








nrA
i -






-----=^----


I-]-






I-I-

K5-


S--



'-I

i--
^__61~

-r-



i _1




;-l-










-i_ _--
~ ~ I
L1


I- -F-_


-Q


?--F



___ '~


---
I-- ------if--i "


0 50 100 150 200 250300350-80

Corrected Declination (0)


0 40 80

Inclination (0)


0 5 10 15
MAD (0)


Figure 2-7. Site 1210 component inclination and declination from discrete samples (open

squares). Inclination and rotated declination from the shipboard pass-through
magnetometer after AF demagnetization at peak fields of 20 mT (gray line). Chrons
are labeled according to Cande and Kent (1992). Black indicates normal polarity,
white reverse polarity. Also shown are the MAD values calculated for discrete sample
data (after Kirschvink, 1980).


I I


20- _
20

_-J i^


I '


Cd'


100


Chrons




Cln




Clr.lr
Clr.ln



CI r,2r



C2n

C2r.lr
C2r. In

C2r.2r




C2An.ln

C2An.lr
C2An.2n
C2An.2r
C2An.3n



C2Ar


C3n.ln

C3n.2n
C3n.3n

C3n.4n

C3r
C3An.ln

C3An.2n
C3Bn


Hiatus


^^,_



i-..










Hole 1211A


- 30 --O ,

a 2'



40






50-






60 I I 1
0 50 100 150 200250 300350 -80 -40 0 40 80
Corrected Declination (o) Inclination (0)


Chrons


0 5 10 15
MAD (o)


Figure 2-8. Site 1211 component inclination and declination from discrete samples (open
squares). Inclination and rotated declination from the shipboard pass-through
magnetometer after AF demagnetization at peak fields of 20 mT (gray line). Chrons
are labeled according to Cande and Kent (1992). Black indicates normal polarity,
white reverse polarity. Also shown are the MAD values calculated for discrete sample
data (after Kirschvink, 1980).










Hole 1212A Chrons
I II


Cln


10
Clr.lr
SC-:ln Cr.ln


20 I Clr.2r
20- -


C2n .1

------------_ --
30 9 C2r


C2An.ln
-,p


,s i C2An.Ir
40 C--2An.2n
C2An.2r
C2An.3n


50 Hiatus
0 C3r

r C3An.ln
S-o C3An.lr
C3An.2n
60- C3Bn
C3Br
C4n.In
C4n.2n

70 Hiatus
0 50 100 150 200 250 300350-80 -40 0 40 80 0 5 10 15 20
Corrected Declination (o) Inclination (0) MAD (0)

Figure 2-9. Site 1212 component inclination and declination from discrete samples (open
squares). Inclination and rotated declination from the shipboard pass-through
magnetometer after AF demagnetization at peak fields of 20 mT (gray line). Chrons
are labeled according to Cande and Kent (1992). Black indicates normal polarity,
white reverse polarity. Also shown are the MAD values calculated for discrete sample
data (after Kirschvink, 1980).

























0 0.02 0.04 0.06
frequency (k.y. -1)


Site 1207 5.2-5.8 Ma


obliquity


0.08 0.1 0 0.02 0.04 0.06 0.08 0.1
frequency (k.y. I)


Site 1207 7.2-7.7 Ma
obliquity


0 0.02 0.04 0.06
frequency -1)


Siobliquity




II


0.1 0 002


Site 1208 2-3 Ma


0.04 0.06
frequency (k.y. I)


0.08 0.


0 0.02 0.04 0.06
frequency (k.y. 1)


0.08 0.1 0 0.02 0.04 0.06
frequency (k.y. 1)


Site 1210 2.2-2.8 Ma


0 0.02 0.04 0.06
frequency (k.y. -I)


0.08 0.1


0.08 0.1


I I I
obliquity
ot Site 1211 2.2-2.8 Ma










0 0.02 0.04 0.06 0.08 0.1
frequency (k.y. -1)


Figure 2-10. Power spectra from a) Site 1207, b) Site 1208 c) Site 1209, d) Site 1210, and e) Site
1211 for reflectance data placed on a Cande and Kent (1995) age model.















SSite 1207


I ,,. .N -- 0 .

C 30 0.38
4 A-
-4 I
0 200 400 Age (ka) o 0 800o o0







101200 1400 .1600 100 200
00.4


-4-
000 1200 140 Age (ka)
SIJI
2000 2200 2400 2600 280
/ 0.43
740 C42
S60"" 0.4 1cC
.50 q.. Z. /NY








/N- I I I -


S4000 2200 2400 2 ( 4600 2Mo 3000
S, i Ii 03
-4




S000 200 5400 Age (ka) 56 00 5so 4000
M' 0.39 ,
,j 0.38










." I" ,. 41 '
-4


7000 7200 7400 Age (ka) 5600 7500 6onO
85

24-



6DW0 6200 6400 Age (ka) 660o 60{ 700L)

Figure 2-11 The astronomical solution for obliquity (Laskar et al., 1993) compared with tuned
', .',

K 111 I I I
y),
-4





7000 720 7400 Age (ka) 76,o -sm 800


Figure 2-11. The astronomical solution for obliquity (Laskar et al., 1993) compared with tuned

L* reflectance data from Site 1207 for the 0-8 Ma interval. The reflectance data

filtered using a band-pass filter centered on 41kyrs is shown in the lower part of each

frame. Black indicates normal polarity and white reverse polarity. Heavy line on L*

reflectance data indicates intervals where the cyclicity is best developed.













Site 1208


-I




-6---- I -
1000 1200 1400 4.,. 1600 1800 2000

-2


ii0 0J39
I I 0.43
I0
-2

1000 1200 1400 Age 600 1800 1000









2000 2200 2400 Age (ka) 2600 2800 3000
0.42






) 8 0.415$ 0




e 'iu, 22 V Vl' 041 wt





3000 3200 3400 Age (ka) 3600 3800 4t000
= ,'oo.4 03






0 0.394 .
0.38




4000 4200 4400 Age ,, 4600 4800 5000




I ir in r w t
Il.i, ,'
4o ,, '45 R










30 0.38





5000 5200 5400 Age (ka) 5600 5800 6000

Figure 2-12. The astronomical solution for obliquity (Laskar et al., 1993) compared with tuned

L* reflectance data from Site 1208 for the 1-6 Ma interval. The reflectance data
filtered using a band-pass filter centered on 41kyrs is shown in the lower part of each
frame. Black indicates normal polarity and white reverse polarity. Heavy line on L*
reflectance data indicates intervals where the cyclicity is best developed.
Figue 212. he stroomial sluton fr oliquty Laskr e al. 193) cmpaed 00.43ne
Q 70etnedt fo ie10 o he16M nevl Terfetnedt
ct 60 rn adpssfle etee n4kysi hw i h oe pr fec
0 'jilt'0. 4 j 2ml oart adwht rvrs olrty eaylieonL
40- 0.39- idcts nevaswee h yliiyisbs evlpd














Site 1209




1 10 Ag k 60 20 S
I _.0.38 'I .



1200 1400 Age (ka) 1600 1800 2000


9)1 I 1,.43


20M 2200 2400 Age ki 260 2800 3000




-- v4




3000 3200 3400 Age (ka) 3600 3_o 400


3.42 R- -

0.39 ...
0.38






0.43



0.38


., "I. '" l -. .. "

S.3a )
0 38,


4200


4400 Age (ka) 4600


_Ij V V


'V V


5000 5200

960 -





-8I
670 6200'7




600) 6200


I I ~0


1 ..
" '* v- !. -' '. .
\; o.3- ^ ^ -. -


5400 Age (ka) 5600


/t


6400 Age (ka) 66o0


6800


o 43
..
,' I ,

, 4'8
o.s' ,. =.


7000


Figure 2-13. The astronomical solution for obliquity (Laskar et al., 1993) compared with tuned
L* reflectance data from Site 1209 for the 1-7 Ma interval. The reflectance data
filtered using a band-pass filter centered on 41kyrs is shown in the lower part of each
frame. Black indicates normal polarity and white reverse polarity. Heavy line on L*
reflectance data indicates intervals where the cyclicity is best developed.


- TX r 'F '
"I,.-i

'a 'I' () *Q i. il,1'V
-'-F >/1y~xN~~- ~ -


1"- -

'7'

0
-4
_R _


<
(
(
(


--












Site 1210
0.43

0 ,,0.43
40 4 4/ A 0





S1000 1200 1400 Age (ka) 1600 18oo 20o
90 "0.43

0.4 4
4- 039



2000 2200 2400 Age (ka) 2600 2800 low


0 1 t 1 1 0.43
s io- ''' o.0
041
4- 0_n38


3000 3200 3400 Age (ka) 3600 3800 4N0X


90 043

09 0.4l

2 Wi 0.38
:4,

4000 4200 4400 AgeC II 46 480W 50


Figure 2-14. The astronomical solution for obliquity (Laskar et al.,, 1993) compared with tuned
L* reflectance data from Site 1210 for the 1-5 Ma interval. The reflectance data
filtered using a band-pass filter centered on 41kyrs is shown in the lower part of each
frame. Black indicates normal polarity and white reverse polarity. Heavy line on L*
reflectance data indicates intervals where the cyclicity is best developed.












Site 1211




i^6o' A ,'
80 0 43








04 0.38


2000 2200 2400 A Li 2600 2800 3000
00 9
IV 0. '0.38






-4




3000 200 3400 .. 3600 3800 4000






0 I4
-4D







L4 0.38 E


4000 4200 4400 L 4600 4SC 500


Figure 2-15. The astronomical solution for obliquity (Laskar et al., 1993) compared with tuned
L* reflectance data from Site 1211 for the 1-5 Ma interval. The reflectance data
filtered using a band-pass filter centered on 41 kyrs is shown in the lower part of each
frame. Black indicates normal polarity and white reverse polarity. Heavy line on L*
reflectance data indicates intervals where the cyclicity is best developed.



























0 0.02 0.04 0.06 0.08 0.
frequency (k.y. )


Site 1208 2-3 Ma











S /Ii

: -k~j ^V ^v w


0 0 02 0.04 0.06
frequency (k.y. -1)


0.08 0. 1


0.02 0.04 0.06
frequency (k.y. -1)


0 0.02 0.04 0.06
frequency (k.y. 1)


0 0.02 0.04 0.06 0.08 0.1 0 0.02 0.04 0.06 0.08 0.1
frequency (k.y. ') frequency (k.y. 1)


Figure 2-16. Cross-spectral analysis from a) Site 1207, b) Site 1208 c) Site 1209 d) Site 1210 and
e) Site 1211. Power spectra for the tuned reflectance data (black) and for the
astronomical solution for eccentricity and obliquity (red). Coherence values between
the astronomical solutions and reflectance data are shown below.


0.08 0.1


0.08 0.1









CHAPTER 3
INTEGRATED NEOGENE MAGNETIC, CYCLE AND BIO- STRATIGRAPHY FROM ODP
SITE 1208 (SHATSKY RISE, PACIFIC OCEAN)

Introduction

ODP Site 1208 was drilled in 2001 on Shatsky Rise, a large igneous province in the NW

Pacific Ocean. A single hole drilled at the site has produced a magnetic polarity stratigraphy for

the 0-12 Ma interval. Sedimentation rates decrease from 4-5 cm/kyr in the Brunhes and

Matuyama chrons to less than 1 cm/kyr at the base of the studied section. A revised planktonic

foraminifer biostratigraphic zonation has been developed for the NW Pacific Ocean using the

seventeen most isochronous foraminifer datums. This scheme has been integrated with

nannofossil events, and with the magnetic stratigraphy. Cycles in the reflectance (L*) can be

matched to astronomic solution for obliquity allowing astronomic calibration of polarity chron

boundaries, and planktonic foraminifer and calcareous nannofossil datums. Astronomic ages for

polarity chron boundaries are consistent with the ATNTS2004 timescale (Lourens et al., 2004) in

the 1-5.2 Ma interval, however, between 5.2 and 6.2 Ma, astronomic ages from Site 1208 differ

significantly (by 300 kyr) from the ATNTS2004 timescale.

As polarity reversals can be considered globally synchronous, the integration of polarity

chron boundaries and biostratigraphies has become a powerful means of calibrating

biostratigraphic zonations, and determining synchroneity of biostratigraphic events (see

Berggren et al., 1995a,b). Early work on Neogene foraminifer biostratigraphy in the North

Pacific Ocean on Deep Sea Drilling Project (DSDP) Sites 173, 296 and 310 (Keller, 1979a,b,c)

was augmented by foraminifer and nannofossil work on ODP Leg 138 in the eastern equatorial

Pacific (Raffi and Flores, 1995; Shackleton et al., 1995a). ODP Leg 138 biostratigraphies were

integrated into well-defined magnetic stratigraphies (Schneider, 1995) and cyclostratigraphies

based on gamma ray attenuation (GRA) bulk density data. Correlation of GRA bulk density









cycles to astronomical calculations for solar insolation provided robust age models for Late

Miocene to Recent sediments (Shackleton et al., 1995b). The ODP Leg 138 age models were

among the first astrochronologies developed for the Late Miocene to Quaternary, and hence the

biostratigraphies generated from ODP Leg 138 sites were rather precisely calibrated. Berggren

et al. (1995a,b) incorporated ages and bio-magnetostratigraphic data from ODP Leg 138 into

their review of bio-magnetostratigraphic correlations for the Cenozoic and Quaternary.

ODP Site 1208 offers the opportunity to refine biomagnetostratigraphic correlations for the

late Neogene. The attributes of ODP Site 1208 include: good preservation of foraminifers and

calcareous nannofossils, relatively high sedimentation rates compared to ODP Leg 138 sites, and

a robust age model based on magnetic polarity stratigraphy and correlation of reflectance data to

astronomical solutions.

The study of ODP Site 1208 is a continuation of the work presented in Chapter 2, which

deals largely with ODP Leg 198 sites other than Site 1208. An initial astrochronology for ODP

Site 1208 (Chapter 2, Evans et al., 2005) was based on correlation of the shipboard reflectance

(L*) data (Shipboard Scientific Party, 2002a) to the astronomical solution for obliquity of Laskar

et al. (1993). Here, we update the Site 1208 astrochronology using the new astronomic solutions

of Laskar et al. (2004), present the Site 1208 magnetostratigraphy, foraminiferal and nannofossil

biostratigraphy, and link these stratigraphies to the new astrochronology. The recalibration of

the Site 1208 age model makes little difference to the chronology presented in the previous

chapter (and in Evans et al., 2005) because the astronomic solutions in the 0-12 Ma interval do

not change significantly in Laskar's two calculations (Laskar et al., 1993; 2004).

Today, Shatsky Rise (Figure 3-1) lies in a subtropical water mass toward the north end of a

warm-water mass known as the Kuroshio Extension Current (Shipboard Scientific Party, 2002b).









North of the Northern High of Shatsky Rise (Figure 3-1) lies a significant front, a transition

region between subtropical and subarctic water masses. The transition zone waters are derived

from off the coast of northern Japan, where the cold, nutrient-rich Oyashio Current mixes with

the warm, nutrient-poor Kuroshio Extension Current. Middle Miocene calcareous plankton

assemblages are rather uniform and diverse across Shatsky Rise and display warm, subtropical

affinities. Since the Late Miocene, however, a faunal and floral gradient has been established

across Shatsky Rise (Shipboard Scientific Party, 2002b). Calcareous plankton assemblages

progressively loose their warm-water taxa along a traverse from south to north across the

Shatsky Rise. At Sites 1207 and 1208 (Figure 3-1), there is a marked decrease in diversity in

assemblages that assume temperate (occasionally cold-temperate) affinities, relative to sites

further south. The changes in calcareous plankton assemblages are paralleled by a progressive

decrease in calcareous preservation from north to south (Shipboard Scientific Party, 2002b).

One of the most noticeable features of the upper Miocene through Pleistocene sections

recovered at Shatsky Rise is the decimeter- to meter-scale cycles between darker and lighter

lithologies. The darker-colored intervals, in general, contain larger amounts of well-preserved

biosiliceous material, and contain calcareous plankton assemblages that have cold-water

affinities and have undergone relatively enhanced dissolution. Calcareous plankton preservation

is enhanced in the light-colored layers that are poorer in diatoms and represent warmer-water

intervals when Site 1208 was located in a subtropical water mass, similar to the situation at Site

1208 today and for the Southern High through most of the Neogene (Shipboard Scientific Party,

2002b).









Site Location and Lithology

ODP Site 1208 is located in 3346m of water on the Central High of Shatsky Rise (Figure

3-1). The Central High of the Rise had not been drilled prior to ODP Leg 198, and the

sedimentary sequence at the site revealed -260 m of Upper Miocene to Recent sediments with

-60m of more condensed Lower and Middle Miocene below. A total of 314.17 m of Neogene

age sediment was recovered at the site with an average recovery of 95%. The Upper Miocene to

Recent section is composed of nannofossil ooze and nannofossil clay with diatoms and

radiolarians, and an average carbonate content of 53% (Shipboard Scientific Party, 2002b).

Since 3 Ma, the average sedimentation rates were 4.2 cm/kyr. Prior to 3 Ma, sedimentation rates

decrease progressively reaching 1 cm/kyr at -8 Ma. The character of the seismic reflection

record at the site, along with the relatively high sedimentation rate that prevailed during the

Pliocene-Pleistocene, suggests that the stratified lens of sediment at the site constitutes a drift

deposit formed by current redistribution of sediment that settled on the Central High (Shipboard

Scientific Party, 2002b). The sediment drift deposits at Site 1208 are somewhat similar to those

drilled along the Meiji Seamount during ODP Leg 145 in that both sections comprise fine-

grained sediment devoid of sedimentary structures other than bioturbation (Rea et al., 1993).

Magnetic Stratigraphy

Magnetic measurements on half cores from Site 1208, using the shipboard pass-through

magnetometer, revealed an unambiguous magnetic stratigraphy, ranging in age from Recent to

Upper Miocene (Figures 3-2, 3-3 and 3-4). The shipboard data are based on a single

demagnetization step (20 mT). This abbreviated treatment was necessary to preserve the

sediment magnetization for later shore-based study, and to maintain core-flow through the

shipboard core laboratory during the cruise. These shipboard data are supported using discrete

sample cubes (7cm3) collected from the working halves of cores, which were measured at the









University of Florida. The discrete sample cubes were AF demagnetized in 5mT increments up

to peak fields of 80 mT. A steep drilling related overprint was removed by 20 mT peak field

(Figure 3-5), and the primary magnetization was defined using the standard least squares method

(Kirschvink, 1980), giving low maximum angular deviation (MAD) values indicating well

defined component magnetizations (Figures 3-2, 3-3 and 3-4).

An initial age model and initial estimate of interval sedimentation rates were calculated

using the magnetostratigraphy and the geomagnetic polarity timescale (GPTS) of Cande and

Kent (1995) (Figure 3-6a). Sedimentation rates decrease down section averaging 4-5 cm/kyr in

the Pleistocene, 3.5-4 cm/kyr in the Pliocene and 1-2 cm/kyr in the Miocene. The duration of the

Reunion subchron given in the Cande and Kent (1995) GPTS (10 kyr) causes a large increase in

the sedimentation rates in the polarity zone correlative to the Reunion subchron (Figure 3-2).

Using a revised age and duration for the R6union subchron (Channell et al., 2003), sedimentation

rates in the polarity zone correlative to the Reunion subchron are reduced to ~4 cm/kyr in

keeping with surrounding sedimentation rates.

Numerous excursions can be identified in the shipboard magnetic stratigraphy particularly

in the Matuyama Chron, one of which (at 103 mbsf) is confirmed by a single discrete sample

corresponding to an age of 2.283 Ma. Channell et al., (2002) identified seven excursions in the

Matuyama chron at ODP Site 983 in the North Atlantic that have been labeled: Santa Rosa (932

ka), Clr. n. r (1048 ka), Punaruu (1115 ka), Bjorn (1255 ka), Gardar (1472-1480 ka), Gilsa

(1567-1575 ka), and C2r.lr.ln (1977 ka).

At ODP Site 1208, shallow inclinations are seen in shipboard data that appear to be

correlative to Santa Rosa (950 ka), Punaruu (1123 ka), Gardar (1450 ka), Gilsa (1522 ka), and

C2r. Ir. In (1976 ka) (Figure 3-2). An interval of shallow inclination at 896 ka at Site 1208 may









correspond to the Kamikatsura excursion that originates from the work of Maenaka (1983).

Three intervals of shallow inclination are also noted in the Brunhes chron with ages of 134, 193

and 262 ka close to the published ages for the Blake excursion (120 ka), Iceland Basin excursion

(189 ka) and 8a (260 ka) of Lund et al. (2001) (Figure 3-2). One potential excursion is noted in

the Gauss chron (Figure 3-3) and three potential excursions in the Gilbert chron (Figure 3-5).

The ages for the Santa Rosa, Blake, Iceland Basin and 8a are calculated by assuming constant

sedimentation rates within the Brunhes and subchron Cir. Ir. Ages for other excursions are at

Site 1208 are calculated from the astronomic age model described below. All the postulated

excursions in the Site 1208 record should be regarded with some caution as they are based on a

single demagnetization step (20 mT peak field) from shipboard data.

Cycle Stratigraphy

Shipboard gamma ray attenuation bulk density data and L* reflectance data (Shipboard

Scientific Party, 2002), show a prominent cyclicity in the 1-6 Ma interval, that, based on the

initial age model has a period close to 41 kyr (see Chapter 2, Evans et al., 2005). Using the

astronomical solutions of the Laskar et al. (2004), the L* reflectance data was tuned to obliquity

by matching the L* output of a filter centered on 41 kyr to the orbital solution for obliquity

(Figure 3-7). The resulting interval sedimentation rates for the 1-6 Ma interval are given in

Figure 3-6b. The tuned ages for reversal boundaries, based on this match, are given in Table 3-2.

The astronomical calibration of Site 1208 presented here is a recalibration of the astronomical

timescale of Evans et al., (2005) using the updated astronomical solutions of Laskar et al. (2004).

The recalibration to the new astronomic solutions resulted in little change to the astronomic ages

for Site 1208 relative to those given by Evans et al. (2005). Comparison of polarity reversal ages

with other timescales, and with results from IODP Site U1313 (Chapter 6), indicates close









agreement with differences < -60 kyrs between 2.6 Ma and 5 Ma (Table 3-2). Beyond 5.2 Ma,

the differences with respect to other timescales increase to over 100 kyr. In the 5.5-6 Ma interval,

the polarity reversal ages from Site 1208 are closest to those of Shackleton et al. (1995b) from

ODP Leg 138 (equatorial Pacific). The largest discrepancy beyond 5.2 Ma is with ATNTS2004

timescale (Lourens et al., 2004) where the difference in ages is 300 kyrs. The ATNTS2004

timescale uses the work of Hilgen et al. (1995) from the Mediterranean in this interval.

Calcareous Nannofossils

Calcareous nannofossils were semi-quantitatively analyzed using smear slides and

standard light microscope techniques (Bown and Young, 1998). The following abundance and

preservation categories were used: Species abundance: abundant: >10 specimens per field of

view (FOV), common: 1-10 specimens per FOV, few: 1 specimen per 2-10 FOV, rare: 1

specimen per 11-100 FOV. Total nannofossil abundance: abundant: >10%, common: 1%-10%,

few: 0.1%-1%, rare: <0.1%, barren and questionable occurrence. Nannofossil preservation:

good, moderate, poor (See range chart of Bown, 2005). All core catcher samples were examined

and -60 other samples collected through the Late Miocene to Recent section. Biostratigraphy is

described with reference to the zonal scheme of Bukry (1973, 1975; zonal code numbers CN and

CP added and modified by Okada and Bukry, 1980) for Cenozoic calcareous nannofossil

biostratigraphy.

The middle Miocene-Holocene section yielded a beautiful succession of rich and abundant

nannofossil assemblages. Preservation improved up-section but was also dependent upon which

part of the light/dark sedimentary cycle was sampled. The darker, diatom-rich intervals yielded

more poorly preserved nannofossil assemblages (Shipboard Scientific Party, 2002). The Neogene

nannofossil biostratigraphy indicates a relatively complete stratigraphy for the Pliocene-

Pleistocene (Figure 3-8) and Miocene (Figure 3-9), with all nannofossil zones from CN5 through









CN15 identified by their primary zonal fossils (Figure 3-10). Calcareous nannofossil range charts

are shown in Bown (2005). Zones CN1-CN5 could not be easily distinguished because of the

absence of the marker species Sphenolithus belemnos, Helicosphaera ampliaperta, and

Discoaster kugleri. In addition, a number of CN subzones could not be recognized due to the

absence ofD. kugleri (Subzone CN5b), Discoaster loeblichii, Discoaster neorectus (Subzone

CN8b), and Amaurolithus amplificus (subdivisions within Zone CN9) and an anomalously low

last occurrence (LO) of Triquetrorhabdulus rugosus (Subzone CN10b) (Bown, 2005).

The astronomically calibrated ages of Pliocene to Quaternary calcareous nannofossil

datums from Site 1208 (Table 3-3) are generally consistent with ages from Berggren et al.

(1995b), that are based largely on work from the Mediterranean (Rio et al., 1990). The LO of

Discoaster brouweri, however, differs significantly from Berggren et al. (1995b) in both age and

correlative polarity chron (Table 3-3). The age of 1.95 Ma given by Berggren et al. (1995b),

correlative to the onset of the Olduvai subchron, is based on correlation to Deep Sea Drilling

Project (DSDP) Site 606 in the North Atlantic (Backman and Pestiaux, 1987).

At Site 1208, the FO of Discoaster berggrenii in the Late Miocene is 0.5 Myrs younger

than the age reported in Berggren et al. (1995a). This age is based on correlation to polarity

chron C4r.2r from ODP Leg 138. The age is more consistent with that seen at DSDP Site 608

where the datum is correlated to polarity chron C4n (Ruddiman et al., 1987). The FO of

Discoaster hamatus is a controversial datum (Berggren et al., 1995a) that has very inconsistent

correlation to polarity chrons regardless of latitude. In ODP Leg 138 sites, it is correlative to

subchron C5n.2n, as at Site 1208. The FO of Catinaster coalitus is another controversial datum

that, at ODP Site 1208, is correlated to subchron C5n.2n similar to the correlation at ODP Leg

138 sites. Berggren et al. (1995a) give an age of 10.8 Ma for the FO of Coccolithus









miopelagicus, 200 kyrs younger than the age from Site 1208 (Table 3-3), however the correlation

of this datum to polarity subchron C5r. r at Site 1208 is consistent with the correlation at DSDP

Site 608.

Planktonic Foraminifera

158 samples were analyzed for planktonic foraminifers at -1.5 m intervals, together with

core-catcher samples (from the base of each core) collected shipboard from the 320-m-thick

upper Neogene section at ODP Site 1208. The samples were soaked in a slightly basic solution,

shaken, washed over a 63 [tm sieve and dried at 600C. Specimens of planktic and benthic

foraminifers were picked from the >125 [im fraction. Specimens of all recognizable planktic

species were identified following the classic taxonomies of Kennett and Srinivasan (1983), Bolli

and Saunders (1985), Jenkins (1985), and laccarino (1985). Shipboard and shore-based

occurrence tables were combined to determine a planktic foraminifer biostratigraphy.

Occurrence estimates were based on the following percentages: Rare=l%, rare to few=3%,

few=5%, few to common=8%, common=10%, common to abundant=15%, abundant =>20%,

Planktonic foraminiferal abundance varies from abundant to common through the

Pleistocene and upper Pliocene but declines in the Miocene to few to rare relative to siliceous

microfossils and clay. Temperate-water species dominate many of the Neogene planktonic

foraminiferal assemblages at Site 1208 (Shipboard Scientific Party, 2002b).

The magnetostratigraphically-interpolated ages for many foraminiferal datums on Shatsky

Rise differed significantly from those reported from the southwest Pacific, due to regional

migration patterns. Application of zonal schemes proposed for the southwest Pacific (Jenkins,

1985) and the mid-latitudes were complicated by unexpected changes in the sequence of

foraminiferal datums observed at Shatsky Rise. A revised temperate foraminifer biostratigraphy









for the late Neogene uses seventeen of the most isochronous foraminiferal datums at Shatsky

Rise as zonal markers (shown in Figure 3-11).

Discrepancies between published ages for planktonic foraminifer datums (Berggren et al.,

1995a,b; Lourens et al., 2004) and those identified at Site 1208 are large in some cases. (Tables

3-4 and 3-5). The majority of the magneto-biostratigraphic correlations used in Berggren et al.,

(1995a,b) and Lourens et al. (2004) are from the Mediterranean (Hilgen, 1990), South Atlantic

(Hodell and Kennett, 1987) or South Pacific (Srinivasan and Sinha, 1993). The comparison of

the ages of the planktic foraminifer datums is affected by regional differences and varying zonal

schemes (Tables 3-4 and 3-5).

The LO of Gr. tosaensis at ODP Site 1208 is at 0.292 Ma, significantly younger than the

age of 0.65 Ma given by Berggren (1995b). This datum is taken from the work of Berggren et al.

(1985) and Srinivasan and Sinha (1993) from the southern Pacific and Indian Oceans. The LO

datum of Gr. punticulata has an age of 1.882 Ma at Site 1208, however, an age of 2.41 Ma was

obtained at DSDP Site 607 (North Atlantic) where it is correlative to polarity subchron C2An.2n.

The FO of Gr. truncatlinoides occurs at the same stratigraphic level as the FO of Gr.

toseanis at ODP Site 1208. Following Berggren et al. (1995b), the FO of Gr. toseanis has an age

of 3.35 Ma. At Site 1208, the astronomically calibrated age of the event is 2.015 Ma. The Site

1208 age for this datum is more consistent with the astronomically calibrated age for the FO of

Gr. truncatlinoides of 2.39 Ma from ODP Leg 138 in the eastern equatorial Pacific (Shackleton

et al., 1995a). The LO of Gr. margarita was assigned an age of 3.85 Ma in the ATNTS2004

(Lourens et al., 2004) from ODP Sites 925 and 926 from Ceara Rise. The astronomic age for the

datum at Site 1208 is 3.761 Ma.









Conclusions

ODP Site 1208 has produced a clear magnetic stratigraphy for the 0-12 Ma interval with

sedimentation rates in the Brunhes and Matuyama chrons varying in the 4-5 cm/kyr range. These

sedimentation rates are some of the highest sedimentation rates seen in this interval in pelagic

sediments from the mid- and low latitude Pacific Ocean. This anomalously high sedimentation

rate appears to be due to formation of a drift-type deposit on the Central High of Shatsky Rise.

The relatively high sedimentation rates have allowed identification of polarity excursions in the

Matuyama Chron that have not been previously identified in sediments from the Pacific Ocean.

It is important to stress that these excursions are identified in shipboard pass-through magnetic

data, and are not based on identification of magnetization components. For this reason, the

ratification of these excursional directions must await further (u-channel) studies of these

sediments.

Reflectance (L*) cycles identified in the sediments have allowed astronomic calibration of

reversal boundaries and biostratigraphic datums, by correlation ofL* reflectance data to the

astronomic solution for obliquity (Laskar et al., 2004). Calcareous nannofossil biostratigraphy is

largely consistent with the most recent review of bio-magnetostratigraphic correlations for this

time interval (Berggren et al., 1995a, b). Based on the correlation of planktonic foraminifer

datums to the magnetic stratigraphy at Site 1208, a new planktonic foraminifer zonation for the

northwest Pacific Ocean has been developed that can be precisely correlated to polarity chrons

and astronomically calibrated ages.











Table 3-1. Depths of reversal boundaries from ODP Site 1208. Chrons are labeled according to
Cande and Kent (1992). Ages for polarity chrons are from Cande and Kent (1995)
and Channell et al., (2003).


Chron Ma (CK95) mbsf

Cln 0
base 0.78
Clr.ln 0.99
base 1.07
Clr.2r.ln 1.201
base 1.211
C2n 1.77
base 1.95
C2r.ln* 2.115
base* 2.153 1
C2An.ln 2.581 1
base 3.04
C2An.2n 3.11 1
base 3.22 1
C2An.3n 3.33 1
base 3.58 1
C3n.ln 4.18
base 4.29 1
C3n.2n 4.48 1
base 4.62 1
C3n.3n 4.8 1
base 4.89 1
C3n.4n 4.98 1
base 5.23 2
C3An.ln 5.894 2
base 6.137 2
C3An.2n 6.269 2
base 6.567 2
C3Bn 6.935 2
base 7.091 2
* age from Channell et al. ,2'" .1 ')


Chron Ma (CK95) mbsf


0 C3Br.ln
42.92 base
52.57 C3Br.2n
55.85 base
61.18 C4n. ln
61.67 base
85.01 C4n.2n
92.81 base
99.86 C4r.ln
01.01 base
19.45 C4An
137.8 base
40.64 C4Ar.ln
44.58 base
47.76 C4Ar.2n
56.88 base
172.4 C5n. ln
76.47 base
82.51 C5n.2n
85.46 base
89.28 C5r.ln
91.01 base
94.09 C5r.2n
00.04 base
16.47 C5An.ln
21.51 base
22.25 C5An.2n
31.39 base
35.31
40.34


6.946
6.981
7.153
7.187
7.245
7.376
7.464
7.892
8.047
8.079
8.529
8.861
9.069
9.146
9.428
9.491
9.592
9.735
9.777
10.834
10.94
10.989
11.378
11.434
11.852
12
12.108
12.333


240.33
241.08
241.83
242.95
250.78
251.71
252.46
256
260.66
262.53
264.02
265.69
268.12
269.05
271.85

282.1
287.14
287.69
290.49
291.42
292.17
294.03
298.69
299.63










Table 3-2. Astronomically calibrated ages for reversal boundaries from ODP Site 1208 compared
to ATNTS2004 (Lourens et al., 2004), Cande and Kent (1995), IODP Site U1313
(Evans et al., in preparation, Chapter 6), Hilgen et al., (1995) and ODP Leg 138
(Shackleton et al., 1995b). Differences between Site 1208 ages and published ages are
given in parentheses.


Chron 1208 CK95 (Ma) Hilgen et al. ATNTS ODP Leg 138 IODP Site
tuned age (1995) (Ma) 2004 (Ma) U1313
(Ma) Chapter 6
Cln
base 0.780
Clr.ln 0.990
base 1.062 1.070 (-0.008) 1.072 (0.01)
Clr.2r.ln 1.158 1.201 (0.043) 1.173 (0.015)
base 1.167 1.211 (0.044) 1.185 (0.018)
C2n 1.763 1.770 (-0.007) 1.785 (0.022) 1.778 (0.015)
base 1.944 1.950 (-0.006) 1.942 (-0.002) 1.945 (0.001)
C2r.ln 2.204 2.140 (0.064) 2.129 (-0.075) 2.128 (-0.076)
base 2.214 2.150 (0.064) 2.149 (-0.065) 2.148 (-0.066)
C2An.ln 2.616 2.581 (0.035) 2.582 (-0.34) 2.581 (-0.035) 2.600 (-0.016) 2.616 (0)
base 3.048 3.040 (0.008) 3.032 (0.016) 3.032 (-0.016) 3.046 (-0.002) 3.074 (0.026)
C2An.2n 3.091 3.110 (-0.019) 3.116(0.025) 3.116(0.025) 3.131 (0.04) 3.153(0.062)
base 3.207 3.220 (-0.013) 3.207 (0) 3.207(0) 3.233 (0.026) 3.268 (0.061)
C2An.3n 3.350 3.330 (0.020) 3.330 (-0.02) 3.330 (-0.02) 3.331 (-0.019) 3.346 (-0.004)
base 3.584 3.580 (0.004) 3.569 (-0.015) 3.596 (0.012) 3.594 (0.01) 3.549 (-0.035)
C3n. n 4.164 4.180 (-0.016) 4.188 (0.024) 4.187 (0.023) 4.199 (0.035) 4.144 (-0.02)
base 4.307 4.290 (0.017) 4.300 (-0.010) 4.300 (-0.007) 4.316 (0.009) 4.277 (-0.03)
C3n.2n 4.484 4.480 (0.004) 4.493 (+0.009) 4.493 (0.009) 4.479 (-0.005) 4.500 (0.016)
base 4.601 4.620 (-0.019) 4.632 (0.031) 4.631 (0.03) 4.623 (0.022) 4.631 (0.03)
C3n.3n 4.785 4.800 (-0.015) 4.799 (0.014) 4.799 (0.051) 4.781 (-0.004) 4.760 (-0.025)
base 4.897 4.890 (0.007) 4.879 (-0.018) 4.896 (-0.001) 4.878 (-0.019) 4.889 (-0.008)
C3n.4n 4.987 4.980 (0.007) 4.998 (0.011) 4.997 (0.01) 4.977 (-0.01) 5.009 (0.022)
base 5.182 5.230 (-0.048) 5.236 (0.054) 5.235 (0.053) 5.232 (0.05) 5.273 (0.091)
C3An.ln 5.735 5.894 (0.159) 5.952 (0.217) 6.033 (0.298) 5.875 (0.14)
base 5.955 6.137 (0.182) 6.214 (0.259) 6.252 (0.297) 6.122 (0.167)











Table 3-3. Nannofossil datums for ODP Site 1208 (Bown, 2005). Ages for the datums are
interpolated from the magnetic stratigraphy (this work) and the correlative polarity
chron is given. The datums are compared to ages given by Berggren et al. (1995a, b).
Tuned ages for the datums are compared to ATNTS2004 (Lourens et al., 2004) and
ODP Leg 138 ages for nannofossil datums only (Raffi and Flores, 1995; Shackleton
et al., 1995a).




1208 Berggren et ODP 1208 ATNTS
Datum Depth
Datum ( ) Mag. strat. Chron al. 1995a b Leg Tuned age
Age (Ma) Site 1208 (Ma) chron 138 age (Ma) (Ma)


FO Emiliania huxleyi
LO P. lacunosa
FO G. omega
FO G. caribbeanica
LO D. brouweri
LO D. pentaradiatus

LO D. surculus

LO D. tamalis
LO Large
Reticulofenestra
FO D. tamalis
LO Sphenolithus
LO Amaurolithus
FO D. asymmetricus
FO C. cristatus
LO D. quinqueramus
FO Amaurolithus
FO D. quinqueramus
FO D. berggrenii
FO D. hamatus
FO C. calyculus
FO D. hamatus
FO C. coalitus
LO C. miopelagicus
LO C. premacintyrei
LO C. floridanus


14.24
30.30
43.11
87.90
100.16
116.40

119.08

128.70
163.90

166.66
166.66
168.88
168.88
187.90
207.00
235.52
250.80
250.80
265.94
270.10
274.20
279.70
285.06
295.41
295.41


0.258
0.551
0.784
1.837
2.143
2.510


Cln
Cln
Clr.lr
C2n
C2r. In
C2r.2r


2.572 C2r.2r

2.812 C2An.ln
3.851 C2Ar


3.65
3.65
4.56
4.56
4.735
5.551
6.941
8.075
8.075
9.586
9.792
10.125
10.699
11.009
13.19
13.19


C2Ar
C2Ar
C2Ar
C2Ar
C3n.2r
C3r
C3Bn
C4r.lr
C4r. lr
C4Ar.2n
C5n. ln
C5n.2n
C5n.2n
C5r. lr
C5An.lr
C5An.lr


0.26 0.26
0.46 0.46


1.95 Olduvai
2.46-2.56 M/G
boundary
2.55-2.59 M/G
boundary
2.78 top Gauss


3.6 bas


4.2 top


1.841
1.96 2.146
2.52 2.499


2.63 2.556 2.52


2.78 2.802
3.833


3.95
e Gauss 3.66 3.95
4.03
Cochiti 4.13 4.03
4.750
5.6 C3r 5.55 5.472


8.6 C4r.2r
9.4 C4Ar.2r

10.7
10.9
10.8


8.45



10.38



12.65
13.19


10.79
10.55
10.89
11.02
11.21
13.33


0.29
0.44



2.06
2.39


2.80












Table 3-4. Plio-Pleistocene foraminfer datums, with depths, correlative polarity chron, tuned age
and compared to Berggren et al. (1995a, b) and ATNTS 2004 (Lourens et al., 2004)
from ODP Legs 138 and 111.


Event


LO Gr. crassula
LO Gr. tosaensis
LO Gs. bulloideus
LO B. praedigitata
LO Gt. woodi
LO Gs. bollii
LO Gs. obliquus
LO N. acostaensis
LO N humerosa
LO Gt. decoraperta
LO Gr. puncticulata, FO Gs. tenellus,
FO Gs. elongatus
FO Gr. hirsuta
FO Gr. toseansis, LO Gr. cibaoensis, FO Gr.
truncatulinoides
LO Pu. primalis, LO Gr. limbata FO Ga. parkerae
FO Pu. obliquiloculata, FOB. digitata
LO Gq. venezuelana
LO Ss. paenedehiscens, LO Gt. apertura
LO N. "dupac", FO Ge. siphonifera
LO Gr. pseudomiocenica
LO Gr. juanai, FO Gr. bermudezi
LO Gr. plesiotumida, LO Gs. extremus,
LO Gs. triloba
FO Gr. limbata
LO Gq. conglomerate, LO Gr. sphericomiozea
FO Pu. primalis
LO Gr. inflata
FO Gt. rubescens
FO Gr. puncticulata, LO Gr. conoidea
FO Sa. dehiscens
LO Ge. pseudobesa
FO Ge. calida, FO Gr. crassula, LO D. altispira, LO Ss.
seminulina
LOSs. kochi
LO Gr. margaritae


FO Gs. bulloideus
FO Gq. conglomerate, FO Gr. crassiformis
FO Ga. uvula, FO Gs. extremus,
LO Gr. conomiozea
FO Gg. umbilicata, FO Ge. aequilateralis
FO Gr. sphericomiozea
FO Gr. conomiozea, LO Gt. nepenthes,
FO Gr. pseudomiocenica


Depth 1208
mbsf mag strat
age
0.4 0.007
16.1 0.292
38.2 0.694
43.7 0.797
53.2 1.005
60.5 1.182
66.7 1.331
76.2 1.559
79.6 1.640
83.6 1.736
89.7 1.878


Chron
Site 1208


Cln
Cln
Cln
Clr.lr
Clr.ln
Clr.2r
Clr.2r
Clr.2r
Clr.2r
Clr.2r
C2n


92.3 1.938 C2n
95.2 2.014 C2r.lr


98.5
101.9
108.1
111.4
121.5
123.0
125.8
132.5

135.3
137.2
142.2
146.2
147.4
150.0
151.5
158.2
159.6


2.103
2.171
2.316
2.393
2.632
2.670
2.740
2.907

2.978
3.250
3.154
3.276
3.318
3.391
3.433
3.631
3.740


C2r.lr
C2r.2r
C2r.2r
C2r.2r
C2An. ln
C2An. ln
C2An. ln
C2An. ln

C2An. ln
C2An. ln
C2An.2n
C2An.2r
C2An.2r
C2An.3n
C2An.3n
C2Ar
C2Ar


161.0 3.739 C2Ar
162.4 3.793 C2Ar


165.0
172.0
178.7

182.9
186.5
190.8


3.894
4.165
4.360

4.499
4.669
4.879


Berggren et
al 95ab age
(Ma)


1208
tuned
ae


0.65 Cln


1.004
1.197
1.34
1.562
1.653
1.742
2.41 1.882

1.930
3.35C2An.2n 2.015


2.116
2.164
2.282
2.382
2.621
2.654
2.714
2.902


2.966
3.024
3.147
3.301
3.338
4.5 Nunivak 3.427
5.2 E.Gilbert 3.457
3.637
3.682


3.58 G/G
boundary


C2Ar
C2Ar
C3n.lr

C3n.2n
C3n.2r
C3n.3n


3.708
3.761

3.871
4.187
4.413


4.54
5.6 C3r 4.696
4.2 Cochiti 4.873


ATNTS
Age











Table 3-5. Miocene foraminifer datums, with depths, correlative polarity chron, tuned age and
compared to Berggren et al. (1995a, b) and ATNTS 2004 (Lourens et al., 2004) from
ODP Legs 138 and 111.


Datum


FO Gr. tumida, LO Gs. kennetti
FO Gs. bollii
FO Gs. kennetti
FO Gd. hexagona
FO N. dutertrei, FO Gs. conglobatus
FO Ss. paenedehiscens, LO Gr.
merotumida
FO Ge. pseudobesa, FO Gr. margaritae,
FO Ss. kochi, FO Gr. plesiotumida,
FO N. humerosa, FO Gr. scitula
LO Gr. miotumida c.f.
FO Gr. cibaoensis, FO N. acostaensis,
FO Gr. miotumida c.f.
LO Gq. baroemoenensis
FO Gr. juanai
FO B. praedigitata, FO Gs. obliquus,
FO N. pachyderma dextrall), (sinistral)
FO Gs. ruber, FO Gt. apertura, LO Gq.
dehiscens
FO Gr. merotumida
LO Gr. praemenardii
FO N. "dupac"
LO Gt. druryi
LO Ss. disjuncta
FO Gt. decoraperta
FO Gr. miozea
LO Gr. mayeri
LO N. continuosa
LO Cs. parvulus, LO Gr. panda

FO Gt. nepenthes, FO Gr. mayeri, FO Gr.
menardii
FO Gt. drurvi


Depth 1208 mag
(mbsf) strat age
(Ma)


203.1
209.4
211.3
214.3
217.3
224.5

227.3


233.6
240.2

245.9
251.1
255.6

263.1

270.5
272.6
276.8
282.3
284.3
285.0
291.9
294.1
295.2
296.8

298.9

299.7


5.354
5.608
5.685
5.806
5.934
6.342


Chron Berggren
Site 1208 et al.
(1995b)
C3r 5.6 C3r
C3r
C3r
C3r
C3An.ln
C3An.2n


6.434 C3An.2n 6.0 C3An


C3Ar
C3Bn

C4n.2n
C4r.lr
C4r.lr


7.8 C4n.2n


9.4 C4Ar.ln


C5n. n
C5n.2n
C5n.2n
C5r.lr
C5r. lr
C5r.lr
C5r.3r
C5An.lr
C5An.lr
C5An.lr


12.3 C5An.2n

12.3


11.8
C5r.3r
11.8
C5r.3r


1208
tuned
age
5.327
5.591
5.675
5.816
5.961


ATNTS
2004

5.57




6.2


11.49


11.63


























Northern High
1207


Central High


1208 1as" -0













1 5 and Southern High
S121 He3'os 1 asin




r. -- _i 1209



306 and S -
o1214 j 305 and Soulhrn High
1213 1211


Opn Rise sea-ounts
Olin Rise seamounts


Pacific Ocean


3000 mbsl
4000 misI
5000 mbsl
SQOW mtSI


155'E 160 165' 170'


Figure 3-1. Bathymetric map showing the location of Shatsky Rise in the Pacific Ocean and a
larger map of Shatsky Rise showing the Sites drilled on ODP Leg 198 including Site
1208 on the Central High of the Rise (after Bown, 2005).


40 -
N


o


ji















0 I



LI




n--
UL
20 :'
E:
77


I : I I


1208A

LII


u'


40 k


60


GLL
B,
Ii


- -pi


'2
I-






,,;,,-


100 I ~- I l
0 50 100 150 200 250 300 350 -80
iL n.. Ill iI.,i i l


Blake

Iceland Basin

















n- n


0I


'It
LtI


U
,-

E-


LI
,d


I I
0 40 80
Inclination ( )


Chrons
(CK92/95)


Figure 3-2. Inclination, declination and MAD values plotted against meters below sea floor. Gray

line indicates the AF demagnetization data from the shipboard pass-through
magnetometer at the 20 mT demagnetization step. Open squares indicate data from

discrete samples. The polarity interpretation is shown in black (normal polarity) and
white (reverse polarity) and chrons are labeled according to Cande and Kent (1992,

1995). Excursions are labeled according to Channell et al. (2002) and Singer et al.
(1999). Ages for excursions are calculated from the astronomic age model for Site

1208.


0 2 4 6 8 10 12
MAD (o)











1208A


I''








-3ii


140 V


- -


160 rL
U-






ISO
1-0


'-' i


lj
1:I i

i_-i


-


-9P
u-t


3950


44-05


4938


200 ''--
0 50 100 150 200 250 300 350 -80 -40 0 40 80
Declination (o) Inclination (0)


Chrons


C2r.2r


C2An.ln


C2An.lr

C2An.2n
C2An.2r

C2An.3n


C2Ar


C3n.ln

C3n.lr

C3n.2n
C3n.2r
C3n.3n
C3n.3r

C3n.4n


-j






i































0 2 4 6 8 10 1214
MAD


Figure 3-3. Inclination, declination and MAD values plotted against meters below sea floor. Gray
line indicates data from the shipboard pass-through magnetometer at the 20 mT
demagnetization step. Open squares indicate data from discrete samples. The polarity
interpretation is shown in black (normal polarity) and white (reverse polarity) and
chrons are labeled according to Cande and Kent (1992, 1995). Excursions are labeled
according to Channell et al. (2002) and Singer et al. (1999). Ages for excursions are
calculated from the astronomic age model for Site 1208.












1208


200









220









240

-D

-0




260









280









300


100 200 300
Declination (0)


4- -
















I -


Th----


E--C










-Qr







-F3









i-I_


-40 0 40
Inclination (0)


I-
___ r


~711 --



--~-



--
7---_
c~i



~F-o


Chrons




C3r




C3An.ln _

C3An.2n




C3Ar


C3Br


C4n.2n I


C4r

C4An


C4Ar


C5n.2n


C5r


f C5An

C5Ar


0 2 4 6
MAD ()


Figure 3-4. Inclination, declination and MAD values plotted against meters below sea floor. Gray
line indicates data from the shipboard pass-through magnetometer. Open squares
indicate data from discrete samples. The polarity interpretation is shown in black
(normal polarity) and white (reverse polarity) and chrons are labeled according to
Cande and Kent (1992, 1995). Gray bar indicates indeterminate polarity.


-D---


I I I I I I II ~I I I


_P














N/Up


\S 1208A-2H-3
I 20f A- 191 -5 imbsf 7,95
mbsf = 173 40 Lo rear 0m I
S Lo Treat 0 mT Hi Treat 60 m
Hi Treat 60 mT


1208A-18H-2
mbsf= 158 57
Lo Treat 0 mT
Hi Treat 60T T





5/Un S/Dn
5/Dn

N/Up N/Up N/Up




W E
1208A-I01-5
nmbsf=7 75
Lo Treat 0 mT
Hi Trcar 60 mT
1208A-6H-5
m tmbsf=4894
W E E o Treal 0 mT
Iii Treal 60 mT

1208A-IOH-2 W
o mbsf 84 07
Lo treat i Il
Hi Ireat 60 rm
S/On S/Dn S/Dn



Figure 3-5. Orthogonal projections showing AF demagnetization data from discrete samples.

Open circles represent the vector end point projections on the vertical plane and

closed circles represent vector end point projections on the horizontal plane.
















C 2I,






0 U ,1 i I, 1 2Ix)

0 2 4 6 g 10 12

b)
141






E





1 2 3 4 5 6
Age NkL,.


Figure 3-6. a) Interval sedimentation rates (black line) and age versus depth (red line) calculated
from the magnetostratigraphic data. b) interval sedimentation rates calculated for the
tuned age model for the 1-6 Ma interval.
tuned age model for the 1-6 Ma interval.












80


4_-1
7000





4
7! a 2

-4
1000


4-

.-2_
-4__
-6_
2000 2200 2400 Age (ka) 2600 2800


5400
Age (ka)


5800


Figure 3-7. Reflectance (L*) data (black line) tuned to the astronomic solution for obliquity from

Laskar et al. (2004). Lower plots shows the output of a gaussian filter centered on the

obliquity frequency (0.024), applied to the reflectance (L*) data.


1200 1400 Age (ka) 10 1800
Age (ka)


lJ 5


-22.5
-22





2000


24 5
23.5 -
23 -
22.5
22


24. 5
24
23.5
23


6000


5000


Z/"ijrJ\~\/~\/2rvSrV"Lr~J?/\/J













0-


10-


20-


30

40-


50-


60


70-


80


90-


100 -

110-

120-


130-


140-


tt 150-
-o-
2
E
160-
I--
E 170-


180-


190


EPOCH AGE


(1)

C




0
4-J
O-
Ll









-1 77--


a)

C

(1)
U

0
U -


200 -I15.3_


NANNO DATUMS
RECOVERY PALEOMAG DEPTH (mbsf) AGE (Ma)
1-H

2-H
-14.24) FO hulyi (0.258
3-H
Cn

4-H [.3030) LO P.lacra 55 1)

5-H
(43 11) FO G omg (0 784)
6-H

7-H

Ci r
8-H

9-H

10-H
C2n 1S790) FOG cantbromrco (.141>

11-H
1- 0.16) LO a owerr (2.146)
12-H C2r

13-H
1- 16.40) LO D pentrradiatus 2.499)
S19.08) LO ?urculus (2.556,)
14-H
1- 28A.7 LO l nma le 12.6021
15-H
C2An
16-H

17H 3n

18-H
C2Ar (16390) LO Large Rersu.lofi-eneaa (3.833)

19-H 3 ,

20-H
On 2
21 -X 118 7.901 FO C .cta s(4.75)

22-X
4n


FORAM DATUMS
DEPTH (mbsf) AGE (Ma)
04) LO G. crass (007)



(1611) LO C rosaens (0 292)





(38 2) LO Gs buoloideu (0.694)
(43.7) LO &praedigitator (07971

(53.21)LO ( wood (1.004)

(6051) LQ 6 o (1.197)
(66.7) LO Gs obtiquus (1.34)

(76.2) LO N. acotaensl (1.562)
(79.6) LO humeorsa 1.653)
(8315) LO Cc decoraperra 1.742)
(89.7) LO Gr puncticu jat, FO Ga lnedus FO Gs.elongatu (1.882)
(92.13 FO Gr hirHta (1.93)
(98ss5 F Gca errk LO G, imbr, LO prrrAmo (2.116)
S(101.9) FO digitata, FO P.bl lloculata 2.164)
(106.1) LO Gq.venez~elano 2.2B2)
(1114 LO 6r aperira, LO sposenedehsrrens 12.382

(121 51 FO GesiphoniferaLON dupac (2.621)
(1233 LO Gr pseudomioremnra (2.654)
(125.81 FO Grbermudezi, LOGr.juano 2.714)

(132.5) LO Gr piesieumida. LO G. exremus, LOGs sriob2.902)
(135.3) FO Gr. lraba (2.W6)
(137.2) LO Gq.rongqoerar, LO Gr. phericmrozea (3.024
(142.2) FO P. prm6fis (3.147)
- ; -, . ,
101
Is.

S' ." 37 .' 682
(I 65.) FO Gs. buosdeui (3.871)

(1720) FO Gq ci-ngomeroa, FOC 6ir crssfotr (4.187)

(178.71 FO Ga. uva, FO Gs. extremes, LO Gr. on(omroze (4.4131
(182 9) FO G Umbircara, FO Ge aoequiaeoras (4,54)
1186.53 FO r.sptherWorfozea (4.696)
8 FO Gr, c ;nomze, LO G nepenrhes 14. 31
FOGr) pseadomeionr ca 87


Figure 3-8. Plio-Pleistocene planktonic foraminifer and calcareous nannofossil datums, core
recovery, and magnetostratigraphy, plotted against meters below the sea floor. Ages
in bold are astronomically calibrated ages from this study. Ticks indicate position of
samples taken for foraminifer analysis. Depths in mbsf of datums are given in
parentheses before the datum.

















3r K (207.00) LD D quinqueramus (5.472)


235.52) FO Amaurollthus (6.941
:36n
f3r=3r

L4n
(250,80) FO D buiquer mu- %B8075)
F1D) b2erregg 0niB.0751
C4r 2n
4An

4Ar 2 (265 94) LO D hoar us 9 586
Sr (270.10) FO C calyculI (9.792)

--n (274.20) FO l homatus (10 125)
(279.70) FO C cools (10,699)

(285 06) LO C. mopeloa CuK (11 nOg)

-3
LO C premoacianyrei(13.19)
.5An 1 95"41)LO C.torldants 1,19)

(303.10) FO R.peudoumbdicus ,7npm) (13.70)

Undef.
(314.17) LO 3. heromrphus (13.52)
'- I ;:', ....... ,


(203.1) FO Gr. tumida, LO Gs kenner (5.327)



S214.3} FO (d. heagona (5.816)
217.3) FO NdutrelrP, FO G. congobaus (5..961)


*^ r :,16,494)

(1233.6) LOGr.mrroturmdat (7.0)

(1240.2) FOGt r. i entwiFOl oostcnsrs4

( 245.9) LO Gc. boeraemonenris (7.9)

S(251.1) FO Gr.o jun(B.1)
., .r .. ,,,.. (8.7)


(263.1) FO G. ruber, FO Gt cpetura, LO G, deIs:ens (9.4)

= 1270.5) FO Gr.merotumdo (9.9)
(272.6) LO Gr raemenardt (10.0)
(276.8) FON dupac (0.21




1291.9) LO Gr. moe (i11 )

,r sl. L4,1 I )
- ', .. ,. ., .... .



3 [310.1) FOPt .glorneros Il.( 11)


.. .. ,l .r


Figure 3-9. Miocene planktonic foraminifer and calcareous nannofossil datums core recovery,

and magnetostratigraphy, plotted against meters below the sea floor (after Venti,

2006). Ages in bold are astronomically calibrated ages from this study. Ticks indicate

position of samples taken for foraminifer analysis. Depths in mbsf of datums are

given in parentheses before the datum.










NANNO ZONES
M71 B73,75,0B80
NN21 CN15 F Gf
CN14 Fa O LG.,mo ,"''.7':,"
FO G.omeaa (0.7841


7- a I CN9
Br- b b
r Z- FO Amouraith us (6.941)
C4n 2 1 a a
C4r -- FO qunqurmus (8.075)
9 C4An C NN10 CN8 a
C4Ar 2
[ -LOD.hamotus (9.586)
10- C5n 0 NN9 CN7
SN FO D.hamatus (10.125)
11 NNFO Ccoaitus (10.699)
C5r NN7 b
1 r LO Cfloridanus 13.19)
12- C5Arn CN5
C5Ar NN6 a
13 '
B --- FOReticuIofenestra(>7pm)
14- -
C5ADn NN5 CN4
15- c5Bn ---- 1 FO C.miopeCNgicus



Figure 3-10. Calcareous nannofossil biostratigraphy including the zonations of Martini (1971)
and Okada and Bukry (1980) modified from Bukry (1973, 1975). Ages in bold are
astronomically calibrated ages from this study.













W A -q:
C2 2, 2
o~all i I I ll s~. il j
-i- ^ | ^ I
-^ C


1 I s| I | I I |


ig
.0)
*5cl


.* 0 r Q "3-
E
C
ap.joui~jdua; V*<3U~ pjoyf^L
inn ^


."

aouo6DIU *J93
13


2


saltuadau 'D


vounq!9


N


u 9 a----'-------- i
LO



o 1 Ln M -I
Sa c l-c

m & | j_





* z z z z z zzz z z






am 06 .1 El

SI i uLpuBz UD EUOIPJO/ u Pl j uePW 6u,-i
8
2 jeueooiy eU0oo!j/!A
I 1 i ii i i
(5 ~pZu~saW L!o~l l~lB~aI u!Se
4B
CII~al lPV


S- -I I '


o M CN 9 in wD N 00 ) CM (4 W C
(eU)3E
Figure 3-11. A proposed biostratigraphy for the mid-latitude North Pacific uses 16 planktic
foraminifer datums to divide the late Neogene into 15 biozones. The new stratigraphy
is integrated into the Geomagnetic Polarity Timescale and compared to pre-existing
planktic foraminifer zonal schemes for temperate and tropical region, as well as to
tropical calcareous nannofossil zonations (after Venti, 2006). Abbreviations for
zonations are as follows: B69: Blow (1969) modified by Kennett and Srinivasan
(1981a, 1981b) BKSA95: Berggren et al. (1995b) J85: Jenkins (1985) SK81:
Srinivasan and Kennett (1981a) M71: Martini (1971) B73,75: Bukry (1973, 1975),
OB80 Okada and Bukry, (1980): Ages in bold are astronomically calibrated ages
from this study.


I..
Cih
WUW
MM_


NI
OnC


DC
oU
Z

I-


0
IX


U









CHAPTER 4
PALEOINTENSITY-ASSISTED CHRONOSTRATIGRAPHY OF DETRITAL LAYERS ON
THE EIRIK DRIFT (NORTH ATLANTIC) SINCE MARINE ISOTOPE STAGE 11

Introduction

The Eirik Drift drapes the top of the underlying Eirik Ridge located off the southern tip of

Greenland (McCave and Tucholke, 1986). Magnetic anomalies have not been identified directly

beneath the Eirik Ridge, although the adjacent oceanic crust in both the Irminger Basin and

Labrador Sea is associated with marine magnetic anomaly 24 of Paleocene-Eocene boundary age

(Srivastava and Tapscott, 1986). The Eirik drift is 800 km long and has been constructed by the

interaction of the southwestward flowing Western Boundary Undercurrent (WBUC) and

basement topography (Chough and Hesse, 1985). The WBUC carries water masses originating

from the Norwegian and Greenland Seas that enter the North Atlantic over the Iceland-Scotland

Ridge and Denmark Strait (McCave and Tucholke, 1986; Lucotte and Hillaire-Marcel, 1994).

The WBUC moves over, and constructs the Eirik Drift and then follows bathymetric contours

around the Labrador Basin (McCave and Tucholke, 1986).

Drilling on the Eirik Drift includes Site 646 (ODP Leg 105), and piston and gravity cores

collected during cruises by the CSS Hudson in 1990, the Marion Dufresne in 1999 and the R/V

Knorr in 2002. Seismic records used to extrapolate the sequence recovered at Site 646 indicate

that the drift has been constructed since the middle to early Pliocene (Arthur et al., 1989).

Although sedimentation on the drift sequence was more or less continuous during the Late

Pliocene and Pleistocene, sedimentation rates vary considerably with glacial/interglacial

conditions and with location on the drift.

Piston cores HU90-013-012 (water depth: 2830 m) and HU90-013-013 (water depth: 3380

m) (Figure 4-1, Table 4-1), collected in 1990 during a cruise of the CSSHudson, record the last

glacial cycle at differing water depths on the Eirik Drift (Hillaire-Marcel et al., 1994). Core









HU90-013-013 shows high sedimentation rates in the Holocene while Core HU90-013-012 has

very low Holocene sedimentation rates due to winnowing by the WBUC (Stoner et al., 1995a,

1996). Increases in magnetic concentration and grain size during the early Holocene and at the

MIS 6/5e transition in HU90-013-013, were attributed to detrital influx associated with retreat of

the Greenland Ice sheet (Stoner et al., 1995b). In core HU90-013-013, four discrete detrital

layers were identified within MIS 2 and 3 based on their magnetic properties (coarse magnetic

grain size) and relatively high percent carbonate values. Stoner et al. (1996) correlated three of

these detrital layers with Heinrich events 1, 2 and 4. Stoner et al., (1998) revised the chronology

for core HU90-013-013 by correlation to SPECMAP (Martinson et al., 1987) and refined the

ages and correlation of the detrital layers to North Atlantic detrital layers.

We present data from three jumbo piston cores (JPC15, JPC18, JPC19) collected on the

Eirik Drift in the summer of 2002 during Cruise KN166-14 of the RVKnorr, and from Core

MD99-2227 collected during the 1999 Images campaign (Figure 4-1). JPC15 was taken on the

upper slope of the ridge at a water depth of 2230 m. Core JPC19 was collected from the crest of

the ridge at a water depth of 3184 m, and Core JPC18 from the southern flank of the ridge at a

water depth of 3435 m. Core MD99-2227 was collected from the western toe of the drift at 3460

m water depth. The recovered sediments are mostly dark gray bioturbated silty clays, with clayey

silt and sandy mud, and occasional gray nannofossil/foraminifer rich clayey silt layers (see

Turon, Hillaire-Marcel et al., 1999, for a lithologic description of MD99-2227).

Methods

U-channel samples (2x2 cm square cross-section and 150 cm in length) were collected

from the center of the split face of piston core sections. These samples were measured on a 2G-

Enterprises pass-through cryogenic magnetometer at the University of Florida. Natural remanent

magnetization (NRM) was demagnetized step-wise using alternating fields (AF) in 5 mT









increments for 0-60 mT peak fields, and in 10 mT increments for 60 mT-100 mT peak fields.

Volume susceptibility was then measured using a susceptibility track specifically designed for u-

channels (Thomas et al., 2003) that has a measurement resolution of a few centimeters.

Anhysteretic remanent magnetization (ARM) was applied using an AF field of 100 mT and a

bias DC field of 50 pT. Isothermal remanent magnetization (IRM) was imparted using a 0.5 T

DC field. Both artificial remanences were demagnetized with the same AF steps used to

demagnetize NRM. Principal components were calculated from the NRM data using the method

of Kirschvink (1980) applied to the 20-80 mT interval. Relative paleointensity proxies were

generated by normalizing the NRM data by both ARM or IRM, demagnetized at a common peak

field. A mean of nine normalized remanence values, in the 20-60 mT peak field range, was used

to generate the relative paleointensity proxies. ARM and susceptibility data were also used to

ascertain magnetic grain size changes that help define detrital layers. The parameter karm

(anhysteretic susceptibility), obtained by normalizing ARM intensity by the strength of the dc

field used to acquire the ARM, was divided by volume susceptibility, to determine kam/k, a

proxy for magnetite grain size.

On completion of the magnetic measurements on the u-channel samples, X-radiographs

were taken across detrital layers, identified by u-channel magnetic measurements and carbonate

analyses, to provide a picture of the internal structure of these layers and identify the presence or

absence of traction structures. Discrete toothpick-sized samples, collected at 1-cm intervals

across detrital layers, were used for smear slide observation (Table 4-2) and for measurement of

magnetic hysteresis parameters using a Princeton Measurements Corp. vibrating sample

magnetometer (VSM). Magnetic hysteresis parameters provide a means of estimating magnetite

grain size, and therefore of recognizing grading in detrital layers.









Cores were sub-sampled for oxygen isotope analysis at 5-cm spacing. Samples from Core

MD99-2227 were analyzed at GEOTOP (Montreal) while samples from the KN166-14 cores

were analyzed in the stable isotope laboratory at Rutgers University. For all the cores,

foraminifer shells of the planktonic species Neogloboquadrinapachyderma (left coiling) were

picked in the 150-250 [tm fraction for the isotopic analyses. Planktonic foraminifer species were

used for the isotopic analyses due to the small amount of benthos present in the cores. For Core

MD99-2227, samples were collected at 5 cm intervals for carbonate analyses using an elemental

analyzer.

Age models for the piston cores were constructed by matching relative geomagnetic

paleointensity records and planktic 6180 records to target curves, with the location of magnetic

excursions (Laschamp and Iceland Basin) providing additional age constraints. The combination

of paleointensity records and oxygen isotope data provide enhanced temporal resolution

compared to using either dataset independently.

NRM and Normalized Remanence Record

The natural remanent magnetization (NRM) data for all four cores are shown as

component inclination, corrected component declination, and maximum angular deviation

(MAD) values (Figure 4-2). Cores were not oriented during collection, and therefore declination

data were corrected by aligning the mean declination of each core to North. Twisting within

cores during the coring process is indicated by anomalous declination changes in Core JPC 18

(114.5-189 cm) (Figure 4-2). Core MD99-2227 is affected by stretching in the upper 7 meters

that has significantly affected the magnetization directions (Figure 4-2).









Polarity Excursions

Brief polarity excursions are a characteristic of the geomagnetic field, at least during the

last -2 Myr, and excursions of known age provide useful stratigraphic markers. Component

magnetizations from u-channels indicate directional excursions at 9.3 meters below seafloor

(mbsf) in Core JPC15, at 13.4 mbsf in Core JPC18, and at 18.7 mbsf in Core JPC19 (Figures 4-2

and 4-3). For Core JPC15, the observed excursion is correlated to the Laschamp excursion (-41

ka). For Cores JPC18 and JPC19, the observed excursion is correlated to the Iceland Basin

excursion (-185 ka). Orthogonal projections of alternating field demagnetization data from

intervals recording the Iceland Basin excursion in Cores JPC18 and JPC19 (Figure 4-3) indicate

that the excursions are unambiguously recorded by u-channel samples and by discrete samples

collected alongside the u-channel trough.

Relative Paleointensity

It is generally accepted that the generation of useful paleointensity proxies requires that the

sediments contain magnetite as the only NRM carrier. Also the sediment should have a narrow

range of magnetite concentration, as indicated by magnetic concentration parameters varying by

less than an order of magnitude, and have restricted magnetite grain-size in the few micron grain-

size range, corresponding to pseudo-single domain grains (Tauxe, 1993). There is no evidence

from demagnetization characteristics of NRM, or from hysteresis parameters, for high-coercivity

magnetic minerals such as hematite or pyrrhotite. Using plots of anhysteretic susceptibility

against susceptibility, and the calibration of King et al. (1983), we estimate that these sediments

generally have magnetite grain sizes in the 1-10 [tm range (Figure 4-4). Records of ARM, IRM

and susceptibility (Figure 4-5) show that the concentration parameters generally vary within an

order of magnitude, the limit deemed suitable for determination of relative paleointensity proxies









(Tauxe, 1993). The exception is within the coarser-grained intervals in the early part of

interglacials, where the concentration parameters vary by more than an order of magnitude.

NRM measured on u-channel samples was normalized using both ARM and IRM,

demagnetized at the same peak fields as the NRM. To generate the paleointensity proxies, a

mean of nine demagnetization steps in the 20-60 mT interval were used to calculate mean

NRM/ARM and mean NRM/IRM. Although the two proxies are generally consistent with each

other, mean NRM/ARM has the lower standard deviations and was therefore chosen as the

preferred paleointensity proxy.

Chronology

To construct age models for the four cores in this study, we correlate the planktonic

oxygen isotope records to the benthic oxygen isotope stack (Lisiecki and Raymo, 2004). We then

adjust this correlation to optimize the fit of the relative paleointensity records to the

paleointensity record from ODP Site 983 (Channell et al., 1997; Channell, 1999). Following

Stoner et al. (2003), the paleointensity and oxygen isotope data from ODP Site 1089 were used

to improve the age model for ODP Site 983 particularly in the MIS 3-4 interval. For the Eirik

Drift cores, a combination of oxygen isotope data and relative paleointensity data can produce a

higher-resolution age model than would be possible using either data set independently.

The magnetic excursion recorded at 18.7 mbsf in JPC19 (Figures 4-2 and 4-3) is

interpreted as the Iceland Basin excursion (Channell et al., 1997; Channell, 1999). It lies in a

prominent paleointensity low at 185 ka in JPC19 (Figure 4-6), consistent with the expected age

of this excursion. According to the age model, Core JPC19, from the crest of the drift at a water

depth of 3184 m, has an age at its base of 300 kyrs with a mean sedimentation rate of 10.5

cm/kyr.









In Core JPC18, from southern flank of the Eirik ridge at a water depth of 3435 m,

sediments coeval with interglacial periods are apparently missing, as shown by the lack of

Holocene oxygen isotope values (Figure 4-7). MIS 5e is also absent in the record, because

oxygen isotope values in this interval are too high for full interglacial values. The polarity

excursion observed at 13.45 mbsf (Figures 4-2 and 4-3) is identified as the Iceland Basin

excursion and it occupies a distinct paleointensity low at 185 ka (Figure 4-7), an age consistent

with the observation of this excursion elsewhere. The overall mean sedimentation rate in Core

JPC18 is 9 cm/kyr.

Core JPC15 was taken on the upper slope of Eirik ridge at a water depth of 2230 m. The

polarity excursion observed at 9.3 mbsf in Core JPC15 (Figures 4-2 and 4-3) occurs within a

prominent paleointensity low at 40 ka (Figure 4-8) and is therefore interpreted as the

Laschamp excursion. The base of JPC 15 has an age of 160 ka and the mean sedimentation rate is

15 cm/kyr (Figure 4-8).

Core MD99-2227 shows significant stretching in the upper part of the core, however, the

correlation to the calibrated ODP Site 983 paleointensity record is possible in the lower part

(Figure 4-9). The paleointensity correlation is consistent with the correlation of the planktic

oxygen isotope record to the benthic oxygen isotope stack of Lisiecki and Raymo (2005). These

correlations give a basal age for Core MD99-2227 of 430 ka, and mean sedimentation rates of 10

cm/kyr (Figure 4-9).

Detrital Layer Stratigraphy

The ratio of anhysteretic susceptibility to susceptibility (karm/k) has been shown to be a

useful magnetite grain size proxy (e.g. King et al., 1983; Tauxe, 1993). Although the plots of kam

versus k of each core (Figure 4-4) indicate magnetic grain sizes within a restricted (few micron)

range, the karm/k data plotted versus age (Figure 4-10) indicate distinct broad intervals of low









values of kam/k that coincide with the early Holocene (when recorded), with MIS 5e, and with

the early parts of MIS 7, 9 and 11 (shaded in Figure 4-10). Low values of kam/k indicate

relatively coarse magnetite grain sizes in these intervals. Although Core JPC18 is missing part of

the Holocene, and almost the entire MIS 5e, the intervals of low values of kam/k appear to be

partially recorded.

Volume magnetic susceptibility data measured on u-channel samples from Cores JPC 19

and MD99-2227 show an increase in magnetic concentration in the early Holocene, MIS 5e, and

in the early parts of MIS 7, 9 and 11 (Figure 4-10). These intervals of high magnetic

concentration coincide with the intervals of low values of kam/k (Figure 4-10) that indicate

relatively coarse magnetite grain sizes.

In Core JPC15, high sedimentation rates between 20-60 ka (500-1200 cm) allow the

identification of millennial-scale cycles in volume magnetic susceptibility (Figure 4-5). These

appear to mimic the D/O cycles the Greenland Ice Core (GISP) oxygen isotope record, and are

reminiscent of susceptibility cycles identified by Kissel et al. (1999) in cores along the path of

North Atlantic Deep Water (NADW), and attributed to changes in the strength of bottom

currents. The depth of the WBUC, that varies in response to the relative outflows of water

masses from the Greenland and Norwegian Seas, could also be account for the variations.

In addition to these broad decimeter-scale intervals defined by kar/k and k values, a total

of seventeen cm-scale layers with magnetic properties and percent carbonate values significantly

different from the surrounding sediments have been identified in MD99-2227 (Figure 4-11).

These layers have been labeled according to marine isotope stage and their detrital carbonate

(DC) content. For example, 6LDC indicates a low detrital carbonate (LDC) layer within MIS 6

(Table 4-2).









Eight of the seventeen cm-scale layers are designated detrital carbonate layers (DC) on the

basis of their high detrital carbonate contents. Four of these layers (3DC, 7DCa, 8DC, 11DC) are

recognized by coarser grained magnetic material (compared to the background sediment), as

indicated by low karm/k values (Figure 4-11). One of these DC layers (7DCa) shows a peak in

magnetic susceptibility while the other seven DC layers do not. Two DC layers (5DC, 9DC)

show finer-grained magnetic material (compared to background sediment), and two DC layers

(7DCb, 2DC) are not differentiated by magnetic grain size from the background sediment but all

DC layers coincide with highs in percent carbonate and six show peaks in GRA bulk density

(Figure 4-11). All DC layers are light in color, do not show a sharp base, and appear to show

some bioturbation. The X-radiographs of these layers confirm a high concentration of IRD, but

no laminae or evidence for traction (Figure 4-12). Smear slides indicate a high percentage of

coarse detrital carbonate material in these layers (Table 4-2).

Nine of the seventeen cm-scale detrital layers are designated low detrital carbonate (LDC)

layers (Figure 4-11). These do not feature an increase in percent carbonate, but show a peak in

magnetic susceptibility, a low in karm/k, and an increase in GRA bulk density. These LDC layers

occur within MIS 1, 2, 5, 6, 7, 9 and 11 and show sharp bases, bioturbated tops and are 4-18 cm

thick (Figure 4-11, Table 4-2). The X-radiographs indicate a sharp base and laminae within the

layers (Figure 4-12), some of the laminae are inclined and indicative of traction, implying rapid

deposition from turbidity currents or contourites.

Toothpick-sized samples collected at 1-cm intervals through detrital layers were used to

determine magnetic hysteresis parameters that can be used as a means of assessing the grain size

of magnetite (Day et al., 1977). All but one of the detrital layers exhibit hysteresis parameters

that fall within the pseudo-single domain (PSD) grain size range (Figure 4-13). The detrital









carbonate layer identified in MIS2 (2DC) shows coarse multi-domain magnetite that is

anomalous compared to all other detrital layers (Figure 4-13). For five of the nine LDC layers,

we see evidence for progressive change in hysteresis parameters through the detrital layer

indicative of grading, fining upward from the base of the layer. Bioturbation of the detrital layer

into the overlying sediment could also cause the layer to appear graded. However, the presence

of distinct laminae within the LDC layers shows that no bioturbation of the layer has occurred.

None of the DC layers show this "grading" in hysteresis parameters. The presence of grading in

the LDC layers indicates a turbiditic rather than a contourite origin for these layers.

Smear slides indicate that LDC layers contain little clay and significant amounts of silt-

sized opaque grains, green hornblende and quartz. Trace amounts of detrital carbonate are

present in LDC layers and throughout the rest of the core, whereas the percentage of detrital

carbonate in the DC layers exceeds 10% (Table 4-2).

Discussion

Sedimentation rates on the Eirik Drift have been shown to be greatly affected by changes

in the strength and bathymetry of the Western Boundary Undercurrent (WBUC) that is thought

to be switched off during glacials and active during interglacials (Hillaire-Marcel et al., 1994;

Hillaire-Marcel and Bilodeau, 2000). The core of this current is thought to occupy water depths

between 2500 and 3000 meters (Hillaire-Marcel et al., 1994), resulting in winnowing and almost

complete removal of Holocene and MIS 5e sediment from these depths. Cores from outside the

influence of the flow would be expected to have interglacial sedimentation rates comparable to,

or higher than, glacial sedimentation rates.

When combined with previous studies carried out on the drift, the new results indicate that

both water depth and position on the drift influence interval sedimentation rates. Although the

site of Core JPC18 is located -450 meters below the supposed core of the WBUC, sediment of









Holocene and MIS 5e age is missing at this site. This implies that the WBUC is active at deeper

water depths than previously supposed on the southern side of the Eirik ridge (Figure 4-1). This

may be consistent with a deep branch of the WBUC, with a gyre in the outer Labrador Sea that

feeds the Gloria Drift (Figure 4-1).

Cores HU90-013-013 (water depth 3471 m), JPC19 (water depth 3184 m) and MD99-2227

have relatively high Holocene sedimentation rates of 35 cm/kyr, -13 cm/kyr, and 10 cm/kyr

respectively. Sedimentation rates in cores MD99-2227 and JPC19 appear to be low at the onset

of deglaciation and then increase. This may be due to increased winnowing by the WBUC at the

onset of the deglaciation, offset by increased detrital input as the deglaciation proceeds.

Core HU90-013-012 at 2830 meters water depth lies within the influence of the WBUC

and has very low sedimentation rates in the Holocene (Stoner et al., 1995a, 1996). Higher up the

slope, Core JPC15 at a water depth of 2230 meters has low sedimentation rates in the Holocene

and MIS 5e, although the site supposedly lies outside the main influence of the WBUC. Hillaire-

Marcel et al. (1994) noted that, in core HU90-013-06 at even shallower water depths (1105 m)

on the Eirik ridge, active bottom currents also resulted in very low Holocene sedimentation rates.

Hillaire-Marcel et al. (1994) interpreted DC and LDC layers deposited during the last

glacial cycle at Orphan Knoll, on the western side of the Northwest Atlantic Mid-Ocean Channel

(NAMOC), as being related to ice advances of the Laurentide Ice Sheet that triggered turbiditic

flows down the NAMOC (Figure 4-1). Sediment suspended by these flows is thought to have

deposited cm-scale sandy mud beds rich in detrital carbonate (DC layers) at Orphan Knoll. Not

all the detrital layers observed at Orphan Knoll are recognized on Eirik Drift, although two LDC

layers and one DC layer in Core HU90-0130-013 (Figure 4-1) were considered coeval with

Orphan Knoll detrital layers (Stoner et al., 1996).









The cm-scale detrital layers identified in core MD99-2227 extend the record of detrital

layers beyond the last glacial cycle. Detrital layers on Eirik Drift occur during both glacial and

interglacial conditions. However, the layers occurring in the interglacials are close to the

Terminations in the Holocene, MIS 5, 7 and 11. It is only in MIS 9 that the DC layer appears to

occur in the later part of the interglacial implying that the Laurentide Ice Sheet was present

throughout MIS 9.

Detrital layer 1LDC with an age of 13 ka in MD99-2227 (Table 4-3) is tentatively

correlated to DCO of Stoner et al. (1998). Layer 2LDC has an age of 18 ka and is correlated to

DC1 (16 ka) from Orphan Knoll (Stoner et al., 1998) and with H1 of Bond et al., (1999) from the

central Atlantic. The DC layer 2DC correlates with DC2 of Stoner et al. (1998) and with H2

(Bond et al., 1999). The detrital layer labeled 3DC (39 ka) is correlated to DC4 from Orphan

Knoll and to H4 (38 ka). As discussed above, the characteristics of LDC layers implies

deposition by turbidity currents (derived from the Greenland Slope). If so, this turbiditic activity

is sometimes coeval with Heinrich layers of the central Atlantic and with detrital events at

Orphan Knoll.

The ages of layers designated 2LDC, 2DC and 3DC in this study are consistent with ages

for Heinrich events H1, H2, and H4 (Table 4-3). No identifiable events that coeval with Heinrich

events H3, H5 or H6 are found. Hiscott et al. (2001) identified Heinrich-like detrital layers in

core MD95-2025 from near Orphan Knoll back to MIS 9. Two detrital carbonate layers within

early MIS 5 at Orphan Knoll (H8 and H9 of Hiscott et al., 2001) appear to be coeval with DC

events identified on Eirik Drift, implying that instabilities of the Laurentide Ice Sheet are

recorded at both sites. Detrital carbonate layers within MIS 7 and MIS 9 at Orphan Knoll (H10

and H13 of Hiscott et al., 2001) are coeval with a LDC layers (7LDC and 10 LDC) identified on









Eirik Drift (Table 4-3), implying that the LIS instabilities that triggered the detrital carbonate

layers at Orphan Knoll were coeval with instabilities on the Greenland slope that triggered the

LDC layers on Eirik Drift. Such conclusions are highly dependent on the resolution of

stratigraphic correlation. While stratigraphic correlation of detrital layers from the Orphan Knoll

to the central Atlantic for the last glacial cycle is rather well constrained (Bond et al., 1999;

Stoner et al., 1996, 2000), the correlations beyond the last glacial cycle are considerably more

speculative (e.g. Hiscott et al., 2001; van Kreveld et al., 1996) due to lack of stratigraphic

resolution that inhibits unequivocal correlation of detrital layers.

Conclusions

Piston cores collected from Eirik Drift have produced records of relative paleointensity and

of the Laschamp and Iceland Basin polarity excursions that augment oxygen isotope data for

generating age models. Magnetic data from cores JPC19 and MD99-2227 show broad intervals

of increased magnetic grain size and concentration during MIS 5e and at the MIS 2/1 transition,

consistent with observations from Core HU90-013-013 (Stoner et al., 1995b). Core MD99-2227

also shows a similar increase in magnetic grain size and concentration at the onset of interglacial

MIS 7, 9 and 11, implying that retreat of the Greenland Ice Sheet produced a characteristic

detrital signal at the onset of all interglacial stages over the last 400 kyr.

Seventeen cm-scale detrital carbonate and low detrital carbonate layers are identified in

MD99-2227 (Figure 4-11, Table 4-2). They occur in both glacial and interglacial stages. The

detrital layers can be subdivided into two classes. Detrital carbonate (DC) layers are composed

of carbonate-rich IRD. They usually, but not always, carry a magnetic signal indicating high

magnetic concentration and increased magnetic grain size relative to background sediment. Low

detrital carbonate (LDC) layers have <10% detrital carbonate, usually show evidence (from

magnetic hysteresis ratios) for fining-upward grading, and X-radiograph evidence for traction.









These layers are also usually marked by high magnetic concentration and increased magnetic

grain size relative to background sediment.

Based on the differences between DC and LDC layers, we interpret the former as Hudson

Strait derived detrital layers, and the latter as layers dominated by material from turbidites

derived from the Greenland slope. 1LDC, 2LDC, 2DC and 3DC are correlative with detrital

layers observed at Orphan Knoll (Stoner et al., 1996) (Table 4-3). Three of them (1LDC, 2DC

and 3DC) are coeval with central Atlantic Heinrich layers H1, H2 and H4 (Bond et al., 1999).

Beyond the last glacial cycle, the correlation of detrital layers from Eirik Drift (this paper) to

Orphan Knoll (Hiscott et al., 2001) and to the central Atlantic (van Kreveld et al., 1996) is

limited by the imprecision of stratigraphic correlation (Table 4-3). Nonetheless, as illustrated

here, the use of paleointensity-assisted chronostratigraphy, the combination of relative

paleointensity with standard oxygen isotope stratigraphy, improves stratigraphic correlations

across the northern North Atlantic Ocean (and beyond), and thereby facilitates the interpretation

of detrital layers in terms of their correlation, aerial extent and provenance.









Table 4-1. Core, latitude, longitude, water depth and base age of the core.


Core

JPC15
JPC18
JPC19
MD99-2227


Latitude Longitude Water
depth
-45.57 58.20 2230
-47.13 57.19 3435
-47.60 57.58 3184
-48.22 58.12 3460


Base age
(kyr)
150
300
250
430











Table 4-2. DC and LDC layer properties in Core MD99-2227.


event Thick- depth Age MIS Name k
ness (cm) (ka) peak
(cm)


5 440.22 13.04
14 616.85 18.2
15 663 21.4
21 858.7 39.1
6 1872.3 111.68
16 2019.4 129.34
14 2192.9 152.17
16 2505.4 191.58
12 2700 214.98
6 2872.3 233.42
11 3083.7 266.57
17 3229.2 289.89
5 3536.4 335.6
18 4008.2 391.03
4 4084.2 403.48
7 4133.7 409.57
7 4240 421.43


1/2 1LDC yes
2 2LDC yes
2 2DC no
3 3DC no
5 5LDC yes
5 5DC no
6 6LDC yes
7 7DCa yes
7 7DCb no
7 7LDC yes
8 8DC no
9 9DC no
9/10 9LDC yes
11 11LDCa yes
11 11LDCb yes
11 11LDCc yes
11 11DC no


kan/k % GRAPE % X-Ray Sharp
carb density detr. base
carb.


coarse low peak
coarse low peak
high peak
coarse high peak
coarse low peak
fine high peak
coarse low peak
coarse high
high peak
coarse low peak
coarse high peak
fine high peak
coarse low peak
coarse low peak
coarse low peak
coarse low peak
coarse high peak


10 traction yes
trace traction yes
15 no
40 no
trace yes
70 no
trace traction yes
20 no
25 no
trace traction yes
20 no
30 no
trace traction yes
trace traction yes
5 traction yes
10 traction yes
50 IRD rich no


Grading


yes
yes
no
no
no
no
yes
no
no
no
no
no
no
no
yes
yes
no











Table 4-3. Detrital Layers from other studies considered to be correlative to detrital layers
identified on Eirik drift.


Event Name


H-layers Bond
et al. (1999)
(age ka)

H1 (16.8)
H2 (24)
H4 (38)


Hiscott et al
(2001)
(age ka)
H1(11-12)

H2 (18-22)
H4 (39-42)
H8(92-108)
H9(121-126)


Van Kreveld
et al (1996)
(age ka)
hl (15)

h2 (21)
h4 (40-43)

h7 (128-131)


depth
(cm)


MD99-2227 Stoner et al.
Age (ka) (1998)
(age ka)
440.22 13.04 DCO (12)
616.85 18.2 LDC1 (18)
663 21.4 LDC3 (21)
858.7 39.1 DC4 (36)
1872.3 111.68
2019.4 129.34
2192.9 152.17
2505.4 191.58
2700 214.98
2872.3 233.42
3083.7 266.57
3229.2 289.89
3536.4 335.6
4008.2 391.03
4084.2 403.48
4133.7 409.57
4240 421.43


h12 (189)


H10(231-240)



H13(335-340)


1 1LDC
2 2LDC
3 2DC
4 3DC
5 5LDC
6 5DC
7 6LDC
8 7DCa
9 7DCb
10 7LDC
11 8DC
12 9DC
13 9LDC
14 11LDCa
15 11LDCb
16 11LDCc
17 11DC













48 W


"' 58 N 58N
4"Y -- .^ ... -'K V '----c D rif
Drift
--0- *. JPCI


CANADA \
T VV ^'MD-2024 \ *
,. ,JPC18
Orphan 57 N 57 N
'.- oll 48 W 46 W












5r7



Figure 4-1. Location map showing the Labrador Sea from Hillaire-Marcel and Bilodeau (2000)
and the location of piston cores JPC15, JPC18, JPC19, and MD99-2227. Black
arrows indicate the path of the Western Boundary Undercurrent. NAMOC: Northwest
Atlantic Mid-Ocean Channel.













s 40
4 o Laschamp JPC15
c excursion
= 40
-00 350 C

;:w ir 3To 9
V -200 | 4
150








4000 4
0 500 ]000 I _500 2000


.Pcc 4aIceland Basin
0 excursion c

0 500 000 5et (( n) on 2000
: 250 1 B
-80 excurs f JPCy I50

GO a C
250


050
Depth (cm)



o 4t n clnio, c t c d t ad m u a

-JPCI Iceland as
1 4A tt01"AuJ.r A. 5
20 I







o 500 1000 1500 2000
Depth (cm)

















S MD99-2227
JPC19 Iceland Basin
-. 40 excursion |

33M












34T U 2r 200;;
:" i i : I
|25 4 k a









0 500 1000 20) 2500 2000 00
Depth (cm)










Figure 4-2. Component inclination, corrected component declination and maximum angular'
deviation (MAD) MD99-2227


'; I S I 1 ; 1 i3 ; 200150
i^tlA i *; i. : '2100





0 W I"0 1500 200. 2300 30" .500 4W0
Depth (cm)



Figure 4-2. Component inclination, corrected component declination and maximum angular
deviation (MAD) values for cores JPC15, JPC19, JPC18 and MD99-2227.












Laschamp Iceland Basin
-80 ----~ --I I -
. JPCI5 JPC18


-40 r 4 *
900 910 920 930 0 95(1 1330 130 1350 1360 1370 1380

Wm









900 910 920 930 940 9501 1330 1-40 1390 1360 1370 1390
Depth (cm) Depth (cm)


Iceland Basin Excursion


Discrete sample (lcm3) Discrete sample (8cm3)
JPC18 NUp

section 7


Deconvolved
u-channel data


U-channel
data


Depth- 135 Inm
Lo treat= 0 mT
Hi real= I0W mT


Deplh=18.73m
LO treat= 0 mT
Hi trat= 100 mT






S/Dn


NNUp



I Depth-18.74m
SL treat- 0 mT
Hi treat- 500 mT


-------B


Figure 4-3. a). Component inclination, declination and maximum angular deviation (MAD)
values recording Laschamp and Iceland Basin polarity excursions from piston cores
JPC15, JPC18 and JPC19. Key: U-channel data (closed circles), deconvolved u-
channel data (open squares-dashed line) using the method of Guyodo et al. (2003), 8-
cm3 discrete sample cubes (open squares) and 1-cm3 cubes (diamonds).3b).
Orthogonal projections from the Iceland Basin excursion from cores JPC19 and
JPC18, from u-channel data, deconvolved u-channel data, and discrete samples. Open
circles represent the vector end point projection on the vertical plane. Closed circles
represent the vector end point projection on the horizontal plane.


1855 1860 1865 1870 1875
Depth (cm)


JPC19
section 4


Depth 18.75m
Lo treat= 0 mT
Hi treat= 00 rnT











MD99-2227


0 2 4 6 8 10 12 14
Volume susceptibility (10-3 SI units)
JPC 15


JPC19


4-
l20-25




22


U L



0
0 1 2 3 4 5 6
V,.lueni, Iic pi-II.t, (10-3 SI units)
jI'CIS


Vo1 2 3 4 5 6
Volume susceptibility I (I SI units)


7 0 1 2 3 4
Volume susceptibility (10-3 S1 units)


Figure 4-4. Anhysteretic susceptibility (karm) plotted against volume susceptibility (k) for JPC 18,
JPC19, JPC15 and MD99-2227. Diamonds indicate 'background' sediment, red
squares indicate coarse decimeter-scale interglacial intervals, and blue circles indicate
cm-scale detrital layers. Black lines indicate magnetic grain-size boundaries placed
using the calibration of King et al. (1983).











S25
-JPC19


E II I 5



2P
A vi A i 5 2'i "1
-" '* / '. ^ '.' 1. '



_"r 'p"' '. "


0 30
00

04 a
3- -1 ..






3 --











J S, 1000 1510 2BOO 2SDO
-','









MD99-2227 20
." / / : "" A *,',/,. 0 i
*, I "10 ^ '





10,1


4.4

0 I
0
0.
0 500 1000 1500 2000 2500
Depth (cm)

I i i-' 25

FMD9,9-2227 .



JPC19. Orange-IRM, green-ARM, red-NRM, blue-volume susceptibility.


0_ '0.6
-0.4 $
0.2 2

E 6 -
00


O 10 0 2000 3000 4000
Depth (cm)
Figure 4-5. NRM, ARM, IRM and volume susceptibility for MD99-2227, JPC15, JPC18 and
JPC 19. Orange-IRM, green-ARM, red-NRM, blue-volume susceptibility.























2 -


2.5 .5

4 3
5 isiecki and Raymo (2005).5
5 -4

4.5
30 5
r= 25 5.5
E 20'
10

0 50 100 150 200 250 300

Age (ka)
Figure 4-6. JPC19: Relative paleointensity record correlated to that from ODP Site 983
(Channell et al., 1997; Channell, 1999). Lower plot: planktic 180O data from JPC19
correlated to the benthic 6180 stack of Lisiecki and Raymo (2005). Interval
sedimentation rates are shown in orange.












































40 80 120


S1 I I20 I I I I20
160 200 240 280 320


Age (ka)


. JPC18: Relative paleointensity data correlated to ODP Site 983 (Channell et al.,
1997; Channell, 1999). Lower plot shows planktic 6180 data correlated to the benthic
6180 stack of Lisiecki and Raymo (2005). Interval sedimentation rates are shown in
orange.


3.5
4
4.5

5_




Z 12 2


Y 4

0
C)v


Figure 4-7























JPCIS -3 0
2.5 4
3 4.5
S 3.5
s 3Lisiecki and Raymo (2005)



5
5.5 0

0 20 40 60 80 100 120 140 160
Age (ka)



Figure 4-8. JPC15: Relative paleointensity data correlated to ODP Site 983 (Channell et al.,
1997; Channell, 1999). Lower plot shows planktic 18O data correlated to the benthic
680 stack of Lisiecki and Raymo, (2005). Interval sedimentation rates are shown in
orange.













MD99-2227




i~ft


3.5
4 4*


3.5 Lisieki and Rayrno i2O'i 5
4



25
5.5- 20 _

0 10
0 100 200 300 400
Age (ka)



Figure 4-9. MD99-2227: Relative paleointensity data correlated to ODP Site 983 (Channell et al.,
1997; Channell, 1999). Lower plot shows planktic 6180 data correlated to the benthic
180 stack of Lisiecki and Raymo (2005). Black bar indicates stretched interval due
to coring. Interval sedimentation rates are shown in orange.