Igneous and metamorphic basement rocks of Florida ( FGS: Bulletin 55 )

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Title:
Igneous and metamorphic basement rocks of Florida ( FGS: Bulletin 55 )
Series Title:
Bulletin - Florida Geological Survey ; 55
Physical Description:
xv, 125 p. : illus. ; 23 cm.
Language:
English
Creator:
Milton, Charles, 1896-
George Washington University
Geological Survey (U.S.)
Donor:
unknown ( endowment ) ( endowment )
Publisher:
Bureau of Geology, FLorida Department of Natural Resources
Place of Publication:
Tallahassee, Fla.
Publication Date:
Copyright Date:
1972

Subjects

Subjects / Keywords:
Rocks, Igneous   ( lcsh )
Rocks, Metamorphic -- Florida   ( lcsh )
Petrology -- Florida   ( lcsh )
Genre:
bibliography   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )

Notes

Bibliography:
Bibliography: p. 124-125.
General Note:
Prepared by the George Washington University and the U.S. Geological Survey in cooperation with the Bureau of Geology, Florida Dept. of Natural Resources.

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University of Florida
Holding Location:
University of Florida
Rights Management:

The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier:
ltqf - AAA1643
ltuf - AED9083
alephbibnum - 000843097
oclc - 00979120
lccn - 73621414
System ID:
UF00000245:00001


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Table of Contents
    Title Page
        Page i
    Front Matter
        Page ii
        Page iii
        Page iv
    Table of Contents
        Page v
        Page vi
        Page vii
        Page viii
    Acknowledgement
        Page ix
    Front Matter
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        Page xii
        Page xiii
        Page xiv
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Full Text





STATE OF FLORIDA
DEPARTMENT OF NATURAL RESOURCES
Randolph Hodges, Executive Director


DIVISION OF INTERIOR RESOURCES
Robert O. Vernon, Director


BUREAU OF GEOLOGY
Charles W. Hendry, Jr., Chief





BULLETIN NO. 55




IGNEOUS AND METAMORPHIC
BASEMENT ROCKS OF FLORIDA




By
Charles Milton








Prepared by the
GEORGE WASHINGTON UNIVERSITY
and the
UNITED STATES GEOLOGICAL SURVEY
in cooperation with the
BUREAU OF GEOLOGY
FLORIDA DEPARTMENT OF NATURAL RESOURCES


TALLAHASSEE
1972













DEPARTMENT
OF
NATURAL RESOURCES




REUBIN O'D. ASKEW
Governor


RICHARD (DICK) STONE
Secretary of State




THOMAS D. O'MALLEY
Treasurer




FLOYD T. CHRISTIAN
Commissioner of Education


ROBERT L. SHEVIN
Attorney General




FRED O. DICKINSON, JR.
Comptroller




DOYLE CONNER
Commissioner of Agriculture


W. RANDOLPH HODGES
Executive Director









LETTER OF TRANSMITTAL


Bureau of Geology
Tallahassee
October 5, 1972



Honorable Reubin O'D. Askew, Chairman
Department of Natural Resources
Tallahassee, Florida

Dear Governor Askew:

The Department of Natural Resources, Bureau of Geology, is publishing
Bulletin No. 55 entitled "Igneous and Metamorphic Basement Rocks of
Florida" by Charles Milton, U.S. Geological Survey.

This report describes the basement rocks that have been penetrated by
wells in the State of Florida. These deep-seated igneous and metamorphic
rocks form the structural backbone of the peninsula and can be invaluable
in the determination of the structural history of the State.

Respectfully yours,



Charles W. Hendry, Jr., Chief,
Bureau of Geology





















































Completed manuscript received
April 25, 1972
Printed for the Florida Department of Natural Resources
Division of Interior Resources
Bureau of Geology
by News-Journal Corporation
Daytona Beach, Florida


Tallahassee
1972




iv








CONTENTS


A cknow ledgm ents ..................................................... i
Previous studies ................................... .................... x
Location of wells in Florida (Map, Figure 1A) ............................... xi
List of w ells in Florida (Table 1) ........................................... xii
Introduction........... ...................................... ........ 1
Petrography of Florida igneous-metamorphic rocks ........................... 2
Dating of Florida and Georgia igneous-metamorphic rocks ..................... 8
Chemical analyses of Florida igneous-metamorphic rocks ...................... 9
Descriptions of Florida "basement rocks" ................................... 12
Nassau County, St. Mary's River Oil Corp., Hilliard Turpentine No. 1 .......... 12
Columbia County, Humble, Cone No. 1 ................................. 13
M adison County, Hunt, Gibson No. 1 .................................... 19
Taylor County, Gulf, Brooks-Scanlon No. 1 ............................... 20
Taylor County, Humble, Hodges No. 1 ................................... 21
Jefferson County, Coastal Petroleum, Larsh No. 1 .............. ...... ..... 26
Franklin County, California and Coastal Petroleum, No. 2 Statelease .......... 31
Jackson County, Humble, Tindel No. 1 .................................. 31
W alton County, Pan American, Sealy No. 1 ............................... 37
Flagler County, Humble, Campbell No. 1 ................................. 38
Putnam County, Sun, W estbury No. 1 .................................... 44
M arion County, Sun, Camp No. 1 ....................................... 49
Levy County, Humble, Robinson No. 1 .................................. 51
Volusia County, Grace Drilling, Retail Lumber No. 1 ....................... 55
Volusia County, Sun, Powell No. 1 ....................................... 57
Lake County, Lake County Development, South Lake No. 2 .................. 64
Orange County, W arren, Terry No. 1 ..................................... 66
Indian County, Amerada, Mitchell No. 1 .................................. 66
St. Lucie County, Amerada, Cowles Magazine No. 2 ....................... 76
Osceola County, Humble, Hayman No. 1 ................................. 76
Osceola County, Humble, Carroll No. 1 ................................... 81
Okeechobee County, Amerada, Swenson No. 1 .. ........... .......... 84
Okeechobee County, Amerada, Harris-Holmes No. 1 ........................ 84
Highlands County, Humble, Carlton Estate No. 1 ........................... 92
Highlands County, Continental, Carlton et al. No. 1 ....................... 101
Hardee County, Humble, Keen No. 1 ..................................... 109
Hillsborough County, Humble, Jameson No. 1 ............................. .113
References ............ ..................................... ........ 124
V












Figure
1


Columbia County


Madison County
Taylor County


Jefferson County


14
15
16a, b

17 Franklin County


18
19
20 Jackson County

21 a, b

22 Walton County


23
24 Flagler County

25
26 a, b

27 Putnam County


Marion County


32 Levy County


ILLUSTRATIONS
Page
Humble, Cone No. 1, 3520'-3529', top 7'.
Baked shale with andalusite (?) ............ 3
3520'-3529', bottom 1'. Altered diabase ...... 14
3543'-3555', top. Diabase. ................. 15
4181'-4206' bottom. Amygdular basalt ..... 16
4181'-4206' bottom. Basalt-calcite
(hydrothermal ?) contact .................. 17
4256'-4281' middle. Amygdular basalt. ....... 18
Hunt, Gibson No. 2, 5200'-5210'. Diabase... 19
Gulf, Brooks Scanlon No. 1, 5512'-5517'
bottom. Diabase-basalt ................... 21
Humble, Hodges No. 1, 615312'.
Calcitized basalt. ....................... 22
6155'. Calcitized basalt-diabase ........... 23
61651/'. Calcitized explosion breccia ........ 24
6216'-6219'. Unaltereddiabase ............. 25
Coastal Petroleum, Larsh No. 1, 7789'-7791'.
D iabase ................ ... ......... 27
7791'-7795' top. Baked shale (?)............ 28
7791'-7795' bottom: Calcitized basalt. ....... 29
7909'-7911'. Sandstone, ordinary light and
crossed nicols .......................... 30
California Co. and Coastal Petroleum,
No. 2 State Lse. 224-A, 10325'-10326'.
Sandstone with calcite and dickite (?)....... 32
10520'-10530'. Calcitized basalt ........... 33
10520'-10530'. Baked shale ................ 34
Humble, Tindel No. 1, 8881'-8891' top 54'.
Siltstone................................ 35
8881'-8891' bottom 1'. Amygdular-quartz
basalt, ordinary light and crossed nicols ..... 36
Pan American Petroleum, J. R. Sealey No. 1,
11935'-11940'. Sericitized rhyolite porphyry
orash................................. 37
11935'-11940'. Sericitized rhyolite, or ash. .... 38
Humble, Campbell No. 1, 4624%4'-4626'.
Volcanic agglomerate. ................... 40
4638'-4639'. Volcanic agglomerate ash. .... 41
4643'-4644'. Volcanic agglomerate ash,
ordinary light and crossed nicols ........... 43
Sun, Westbury No. 1, 3879'-3881'.
Ash with fossil .......................... 45
3885'-3887'.Pyroclastic .................... 46
3887'-3891'.Pyroclastic ................... 47
3890'-3892'.Pyroclastic ................... 48
Sun, Camp No. 1, 4574'-4584'. Arkose
with rhyolite ........................... 50
Humble, Robinson No. 1, 4331'-4336'.
Calcitized basalt ....................... 52











Figure
33
34
35

36

37
38
39 a, b

40
41 a, b


Volusia County


Lake County


42 Indian River County


43
44
45
46
47 a, b


St. Lucie County


48 a, b

49 a, b

50 Osceola County

51 a, b

52 a, b

53 a, b


54 Okeechobee County

55

56

57
58
59
60

61 Highlands County


4344'-4356'. Calcitized basalt .............. 53
4358'-4359'. Diabase .....................54
Grace Drilling, Retail, Lumber No. 1,
5424)2'. Rhyolite.........................56
Sun, Powell Land No. 1, 5922'-5925'.
"Weathered" igneous rock ................ 58
5954'-5955'. Diorite ................... 60
5954'-5955'. Diorite with epidote. .......... 61
5955'-5956'. Homfels, ordinary light and
crossed nicols .......................... 62
5957,2-5958'. Hornfels. ................. 63
Lake County Oil Devel. South Lake
No. 2, 6107'-6128'. "Granite", ordinary
light and crossed nicols ................... 65
Amerada Petroleum Corp.,
Fondren Mitchell No. 1,
9444'-9449'. Basalt. ................... 67
9444'-9449'. Diabase ..................... 68
9469'-9474'. Amygdules in basalt ........... 69
9469'-9474'. Amygdule in basalt ............ 70
9484'-9489' T. D. Quartzitic basalt .......... 71
Amerada, Cowles Magazine No. 2, 12734'.
Amygdaloidal basalt, ordinary light and
crossed nicols .......................... 72
12744'. Granite, ordinary light and
crossed nicols .......................... 74
12748' Diorite, ordinary light and
crossed nicols .................. .........75
Humble, Hayman No. 1, 8750'-875.3'.
Rhyolite ................................ 78
8765'-8770'. Rhyolite, ordinary light and
crossed nicols ........................... 79
8786'-8787'. Rhyolite, ordinary light and
crossed nicols ........................... 80
Humble, J. Ray Carroll No. 1,
8042'-8042i''. "Granite", ordinary light
and crossed nichols .................... 82-83
Amerada Petroleum Corp., Marie Swenson
No. 1, 10760'-10770'. Amygdular basalt ..... 85
10760'-10770'. Basalt, non-amygdular
(3 fragments) ............................ 86
10760'-10770'. Altered shale, and
amygdular basalt (3 fragments) ............ .87
10760'-10770'.Basalt. ................... .88
10760'-10770'. Bakedshale .................89
10770'-10780'. Amygdular basalt ............ 90
10830'-10840' T. D. Hydrothermal
quartz, etc..............................91
Humble, Carlton Estate No. 1,
12694'-12699'. Basalt. .................... .93










Figure
62
63
64
65
66

67
68

69


Hardee County


75 a, b

76 a, b

77a, b

78 a, b Hillsborough County


79 a, b

80
81 a, b
82
83
84
85


Page
12715'-12721'.Basalt. ................... 95
12721'-12722'.Basalt ................... 96
12721'-12722'. Basalt with veinlets .......... 97
12771'-12775. Basalt ..................... 98
12826'-12867'. Amygdular basalt with
veinlets ............................... 99
12826'-12867'. Amygdule in basalt ......... 100
Continental Oil, Carlton et al. 12600'-12609'
top. Altered basaltic ash with veinlets ...... 102
12600'-12609' bottom. Basalt with
calcite bands ......................... 103
12614'-12630' lower middle. Zoned
chlorite amygdule in basalt. ............ 105
12641'-12630' lower middle. Amygdaloidal
basalt with veinlets. .................... 106
12629' bottom of hole.
Amygdaloidal basalt with chalcedony (?)... 107
12614'-12630' bottom. Amygdaloidal basalt. 108
Humble, Keen No. 1, 11853'-11857'.
Basalt with quartz veinlet ................ 110
11867'-11877'. Basalt with quartz chlorite
amygdule, ordinary light and crossed nicols. 111
11867'-11877'. Amygdular brecciated
basalt, ordinary light and crossed nicols .... 112
11932'-119:33'. Basalt, ordinary light and
crossed nicols ......................... 114
Humble, Jameson No. 1, 9995'-10003'.
Arkosic sandstone, ordinary light and
crossed nicols......................... 115
10003'-10010. Grit or arkose, ordinary
light and crossed nicols. ............... 116
10010'-10019. Rhyolite .................. 117
10010'-10019'. Rhyolite flow structure ..... 118
10025'.Rhyolite ........................ 120
10040'-10043'. Rhyolite or welded tuff. .... 121
10043'-10053'. Rhyolite ................. 122
10115'-10125'. Basaltic rock .............. 123




TABLES


Tables


Page


la Location M ap ........................................................xi
1 Florida wells drilled into Igneous or Metamorphic rocks ... .. ............ .. xii
2 Isotope dating of Florida (and Georgia) rocks ............................. 5
2a Age determinations Amerada Petroleum Corp. Cowles Magazine No. 1......5
3 Chemical analyses of Florida Igneous-Metamorphic rocks ................... 10
3a Florida igneous-metamorphic rock norms ................................ 11






ACKNOWLEDGMENTS


This work was begun in 1949, with study of the petrography of
the cores and cuttings from Florida, Georgia, and Alabama reported
on by Paul L. Applin (1951) in "Preliminary Report on Buried pre-
Mesozoic Rocks in Florida and Adjacent States" (U.S. Geol. Survey
Circular 91). This was the basic compendium of data than available.
For Florida, the present report may be considered as final or compre-
hensive summary report on these igneous rocks, with inclusion of
much data accumulated during the two decades following the 1951
circular. Mr. Applin and the Bureau of Geology have continued their
helpful interest in this study, and furnished part of these additional
data. George V. Cohee gave valuable counsel and assistance, and Miss
Jean Berdan also of the U. S. Geological Survey contributed paleonto-
logic-stratigraphic data, besides critically reviewing this report. I am
indebted to Dr. A. A. Meyerhoff, Publication Manager of the Ameri-
can Association of Petroleum Geologists for permission to use mater-
ial from a brief account of these rocks published in the Bulletin (Milton
and Grasty, 1969). A grant from the National Science Foundation pro-
vided facilities which were used in the preparation of this report.







PREVIOUS STUDIES


The basic reference work on the petrology of the igneous-metamor-
phic rocks beneath the coastal plain of Florida, Georgia, and Alabama
is by Applin (1951), who gave data on 100 wells drilled in those three
states. Sixty-five wells were drilled in Florida (of which 3 were reported
to have reached granite or diorite, 8 to have reached rhvolitic or other
volcanic rock, and 10 to have reached basalt or diabase). Applin sug-
gested a Precambrian age for the granite-diorite rocks, as well as for
the Peidmont metamorphic rocks in Georgia and Alabama not far
south of the Fall Line. This report indicates no ages greater than Pale-
ozoic, and most of them are much younger.
Data of fossiliferous Mesozoic strata underlying the Florida coastal
plain have been summarized by Applin and Applin (1965, 1967). As
only a few wells have penetrated igneous rocks since Applin's (1951)
publication, comparatively little is added to previous knowledge of Flor-
ida igneous-metamorphic petrology, and most of their discussion is of
previously published data. They describe the coastal plain floor in north-
ern and central Florida as a truncated surface of igneous and sedimen-
tary rocks of "mostly Precambrian(?) and early Paleozoic" age, and
in northern Florida as "late Triassic(?)" igneous rocks. Additional data
on Florida wells, in part unpublished, have been given to us by P. L.
Applin (written common., 1967).
Milton and Hurst (1965) described samples from 13 wells in Georgia
which were drilled into Paleozoic or older granite and crystalline
schist, and from another 26 wells which were drilled beneath the coastal
plain formations into volcanic or sedimentary rock more or less
metamorphosed by igneous contact.
Grasty and Wilson (1967) discussed the Florida igneous rocks
with reference to continental drift. Several of the age determinations
given here were made for their study.
Bass (1969) reported on the petrography of nine Florida basement
rocks and gave three age determinations, cited here in Table 1.
















0

/
I /

--x










Table 1. Florida Wells Drilled into Igneous or Metamorphic Rocks




Depth to Thickness
Top of Of Igneous
Well Applin Type of Igneous or or Meta- Total
Locality (1951) County Rock Meta- Morphic Depth of Bottom Rock Remarks
Fig. I No. morphic Rock Well (ft)
Rock Penetrated
(ft) (ft)


67 Nassau Diabase

42 Columbia Diabase





62 Madison Diabase


4 82 Taylor

5 83 Taylor


Diabase

Basalt
"gabbro"
diabase


6 54 Jefferson Diabase or
basalt


7 Franklin Diabase


4,808


4,824 Diabase


Intrudes lower Paleozoic black
shale.


4,444 Black shale Samples labeled 4,181-4,206 ft
and 4,231-4,281 ft are amygdaloi-
dal basalt. Black shale overlying
diabase at 3,529 ft contains
abundant sercitized andalusite
(?) (Fig. 2a)
5,385 Paleozoic black Sampleslabeled 5,200-5,201 ft are
shale hydrothermally altered diabase.


:3,529*
3,564*
4,1910
4,193*
4,218-
4,267*
1,589-

5,438

6, 153





7,690

7,763*
7,850.
10.4600


5,517 Diabase or
basalt
6,254 Diabase


7,913 Sandstone


10,566
(Driller)
10,507
(elec. log)


Diabase


Altered diabase or basalt.

Upper 12 ft is basalt; lower 89 ft
is diabase gabbro (Applin, 1951).
Upper 10 ft of basalt highly cal-
citic and strongly brecciated. An-
alysis 5: diabase, 6,162 ft. Analy-
sis 6: diabase, 6,216-6,219 ft.





California Co. and Coastal Petro-
leum Co. No. 2 State Lease
224A. Data from P. L. Applin
(written common., 1967) Loca-
tion: Lat. 2947'03"N long. 810
22'51"W, about 13 mi offshore
from Carrabelle, Florida.






Table l. (Continued)


Depth to Thickness
Top of Of Igneous
Well Applin Type of Igneous or or Meta- Total
Locality (1951) County Rock Meta- Morphic Depth of Bottom Rock Remarks
Fig. 1 No. morphic Rock Well (ft)
Rock Penetrated
(ft) (ft)


8 53 Jackson Porphyritic
hornblende
Basalt
(Applin, 1951)
9 Walton Strongly
altered
porphyritic
rhyolite

10 19 Flagler Basaltic and
rhyolitic tuff

11 25 Putnam Volcanic ash


12 23 Marion Rhyolite or
rhyolitic ash


13 60 Levy


Diabase


14 26 Volusia "Rhyolitic(?)
volcanic rock"
(Applin, 1951

15 7 Volusia Metabasalt


16 5 Lake


"Alaskite" or
"granite"


8,890-
8,970-

11,910





4,588



3,873


4,615

4,317



5,403



5,910
5,951-
5,952

6,103


9,245 Middle Devonian
siltstone


11,948 Rhyolite ash
or prorphyry




4,632 Volcanic agglom-
erate of rhyolitic
and basaltic debris
3,982 Ash or rhyolite

4,637 Ash or rhyolite


4,609 Lower Paleozoic
quartzite and
shale
5,424 Rhyolite



5,958 Metabasalt, etc.



6,129 "Alaskite"
(II, L. Tomlinson,
unpub. data)
"Granite"
(Applin, 1951)


Basalt is amygdaloidal.



Pan American No. 1 J. E. Sealey.
Data from Applin (written com-
mun., 1967), cited in letter from
R. T. Violette to P. L. Applin,
June 3, 1960.
Analysis 8: volcanic agglomerate,
4,624 3/4 4,626 ft.

Fossils (?). Analysis 9: ash or
rhyolite, 3,879-3,881 ft.



Top of igneous rock is clayey,
bottom fresh diabase.


"No cores taken in volcanic
rock." (Applin, 1951) cuttings
(5,424 1/2 T.D.) are fresh rhyo-
lite,
Also altered calcareous shale (?).
Volcanic rock altered to clay.
Analysis 7: metabasalt, 5,919-
5,922 ft. Age more than 480 m.y.
Meta-arkose (?) "not studied
petrographically" (Applin, 1951)
(Fig. 2b).









Table 1. (Continued)


Depth to Thickness
Top of Of Igneous
Well Applin Type of Igneous or or Meta- Total
Locality (1951) County Rock Meta- Morphic Depth of Bottom Rock Remarks
Fig. 1 No. morphic Rock Well (ft)
Rock Penetrated
(ft) (ft)


17 Orange


Indian
River


"Granite"






"Andesite"


19 St. Lucie Basalt
Granite
Diorite







20 24 Osceola Rhyolite
21 6 Osceola "Granite"
Arkose(?)

22 Okeechobee "Volcanic"
rocks


6,550






9,410




12,725
12,744
12,748







8,740
8,035
8,035

10,750


6,589 "Granite"






9,488 Diabase




12,748 "Diorite"









8,798 Rhyolite
8,049 "Granite"
8,042 (Applin, 1951)
Arkose (?)
10,838 Basalt


Warner Petroleumn Co. No. 1
George Terry. Data from Applin
(written commun., 1967). Well
61 of Applin nmd Applin (1965).
C SW'. SEA. Sec. 21, T23S,
R31E. No samples available.
Amerada Petroleum Corp. No. I
Frondren Mitchell. Data from
Applin (written common., 1967).
Sec. 28, T31S, R35E.
Amerada Petroleum Corp. No. 2
Cowles Magazine. Well 68A of
Applin and Applin (1965). Anal-
ysis 2: basalt, 12,734 ft, age 89.3
- 2.2 m.y. (Fig. 2d). Analysis 3:
"granite," 12,744 ft, age226 6m.
y. (Fig. 3a). Analysis 4 "dior-
ite," 12,748 ft, age 308 -5 m.v.
(530 + m.y., Bass, 1969) (Fig. 3h).
Age 173 4 m.y.
Analysis 1: granite or arkose,
8,031-8,042 ft, age 530 m.y.
(Bass, 1969) (Fig. 2c).
Amerada Petroleum Corp. No. 1
Marie Swenson. Data from Ap-
plin writtene n common., 1967).
Well 60 of Applin and Applin
(1965). Sec. 5, T36S, R34E.





Table 1. (Continued)

Depth to Thickness
Top of Of Igneous
Well Applin Type of Igneous or or Meta- Total
Locality (1951) County Rock Meta- Morphic Depth of Bottom Rock Remarks
Fig. 1 No. morphic Rock Well (ft)
Rock Penetrated
(ft) (ft)


Okeechobee Rhyolite
porphyry


24 21 Highlands Amygdaloidal
basalt, rhyolite,
porphyry, etc.
(Applin, 1951)
25 Highlands "Volcanic
rock"



26 20 Hardee Basalt "lava
and pyroclastic
rocks" (Applin,
1951)
27 22 Hillsborough Rhyolite tuffs
and flows (Fig.
3c), and meta-
basalt (?)


9,682





12,618




12,601




11,828



10,010


9,840





12,985 Basalt




12,630 Diabase




11,934 Basalt




10,129 Metabasalt (?)


"Depth reported by Applin (1951).


Sun Oil Co.-Amerada Petrole-
um Corp. No. 1 Harris Iolmes.
Data from Applin (written com-
mun., 1967). No samples avail-
able. Sec. 8, T33S, R34E.
Basalt, 12,664 ft, age 183 10
m.y.


Continental Oil Co. No. 1 G. C.
Carlton et al. Data from Applin
(written common., 1967). Well
45 of Applin and Applin (1965).
Basalt, in part hydrothermally
altered and brecciated, also ash
(?). Altered basalt, 11,853 ft., age
143 + 3m.y.
Rhyolite and welded tuff overlies
metabasaltic (?) agglomerate
(Fig. 3d). Analysis 10: metaba
saltic agglomerate, 10,115-10,125
ft. Analysis 11: rhyolite, 10,019-
10,022 ft.











INTRODUCTION


This report describes in detail all the cores and cuttings available from
a large collection of wells which were drilled in the Florida Coastal Plain,
which penetrated rocks older than the Late Cretaceous, Tuscaloosa For-
mation. It summarizes the literature concerned with these rocks. A simi-
lar account of the corresponding rocks in Georgia was given by Milton and
Hurst (1965). The Florida rocks have recently been listed and briefly de-
scribed by Milton and Grasty (1969).
The specimens described number several hundred, from 27 drill holes
in 21 counties over most of Florida north of Lake Okeechobee, and in-
clude nearly all of the deep tests that have penetrated igneous rocks of
the basement during a half century of drilling. To the south of Lake Okee-
chobee, wells have been drilled to greater depths, but only two have
reached rock of pre-Mesozoic age, or of igneous-metamorphic character.*
Although many wells have been drilled into the Florida pre-Cretaceous
basement, and Paleozoic strata have been recognized widely in the northern
part of the state, the nature of the truly metamorphic basement underlying
Paleozoic sedimentary rocks still may be considered virtually unknown.
Twenty-seven wells have penetrated igneous or metamorphic rocks which
appear mostly to be either Mesozoic of Paleozoic intrusive and related vol-
canic sedimentary rocks, or contact-metamorphic rocks affected by such
volcanic activity. Because drilling generally was terminated when such
rocks were penetrated, little or nothing is known of what may underlie
them, or the extent and thickness of the basement rocks themselves.



*Editor's Note: Those are Humble O & R Co. No. 1 Lehigh, the discovery well of Le-
high Acres Field in Lee County, which bottomed in diabase, and Mobil Oil Co. No. 1
224-B F.S.L., a dry hole drilled about 6 miles SW of Englewood in the Gulf of Mexico.
This well bottomed in rhyolite. Age determinations by potassium-origin percentages in-
dicate late Triassic or early Jurassic intrusives for both diabase and rhyolite recovered
in cores from the wells.




BUREAU OF GEOLOGY


The petrography of basement*rock from 27 Florida wells is described
(Table 1); also some 14 isotopic dating from 6 wells in Florida and "
in Georgia (Table 2); and chemical analyses of rocks from 7 Florida
wells are given.
Figure A is a map of Florida showing the locations of the 27 wells
and the counties in which they were drilled. Eight wells in Table 1 not
listed by Applin (1951) are named and located under "Remarks,"
where the source of information also is indicated.
The collection of specimens described in this report, together with
125 thin .sections, have been deposited with the Florida State Bureau
of Geology in Tallahassee.


PETROGRAPHY OF FLORIDA
IGNEOUS-METAMORPHIC ROCKS

The igneous rocks of Florida and southern Georgia include a (prob-
ably) time-related group of diabases, basalts, and rhyolites that are
present from the state line south as far as Lake Okeechobee. Their
K-Ar dating-from 89.3 2.2 to 183 10 m.y.-indicate a Mesozoic
age, and the volcanism is presumably correlative with the widespread
Mesozoic volcanism of the North American Atlantic seaboard and the
Gulf Coast.
These Florida igneous rocks appear to be a southward continuation
of the rocks penetrated in southern Georgia (Milton and Hurst, 1965).
In Glynn County, Georgia, just north of well No. 1 (Table 1; Fig. 1),
which was drilled into diabase, the Humble Oil and Refining Co. No. 1
W. C. McDonald penetrated granophyre from 4,732 to 4,737 ft.
Granophyre commonly is found as a border phase, normally at the top,
of large bodies of diabase. In Clinch County, Georgia, Timber Pro-
ducts Co. No. 1 Wiley P. Ballard, Jr., penetrated amygdaloidal basalt
from 4,210 to 4,232 ft; Brady Belcher et al. No. 1 Lem Griffis pene-
trated rhyolite and welded tuff from 4,348 to 4,588 ft. In contiguous
Echols County, Georgia, in Hunt Oil Co. No. 1 Superior Pines, dia-
base intrudes Paleozoic black shale from 4,115 to 4,150 ft (approx.).
Table 1 and Figure 1 show the presence of very similar rocks in the
northern Florida counties.

"The term "basement" is used variously by different writers; for the purposes of this
report, we define it as crystalline, igneous, metamorphic and unmetamorphosed sedi-
mentary rocks of early Paleozoic or older age, underlying unmetamorphosed (post-
Paleozoic) sedimentary rocks that may contain oil or gas. Some Paleozoic and post-
Paleozoic pre-Cretaceous sedimentary rocks in Florida are intruded locally by ig-
neous rocks, some of which have been dated by radiometric methods and are described
in this report. Unquestioned regionally metamorphosed rocks (e.g., mica, garnet, staur-
olite, kyanite, sillimanite schists, or marbles) have not been found in Florida.







BULLETIN NO. 55


12


Baked shale
Figure 1. Columbia County, Florida, J. P. Cone No. 1, Humble Oil and Refining
Company, 3520'-3529' Top 7 feet.
Carbonaceous shale, with disseminated andalusite (?) Ordinary light,
X22.5.


The association of diabase or basalt, tuff, rhyolite, and granophyre
is so characteristic of many regions of the world that it does not re-
quire emphasis here.
These rocks are found as far south as Lake Okeechobee (e.g., basalt
in St. Lucie County on the east coast, basalt and rhyolite in Highlands
County in southern central Florida, and rhyolite in Hillsborough County
on the west coast). Evidently Mesozoic volcanism extended across
most of the state.
Bass (1969) refers to "The two wells known to penetrate basalt, the






BUREAU OF GEOLOGY


(Hardee County Humble) Keen and (Highlands County Humble) Carl-
ton" as the southernmost "and speculates as to a distinct province
of mafic extrusive rocks in southern or southwestern Florida .. ." which
"may be considerably younger than the rhyolitic rocks ." However,
it may be noted that basaltic rocks exist in northern Florida (Milton and
Grasty, 1969) not to mention Georgia (Milton and Hurst, 1965).
The terms "diabase" and "basalt" are used in this report with the
understanding that they may in some cases refer to essentially the same
rock, crystallized under varying conditions from the same body of
magma. The chilled upper margin may have a basaltic aspect, whereas
the more slowly cooling deeper magma may have the diabasic (ophitic)
texture.
Similar considerations apply as to Gough's (1967) geophysically-based.
interpretation of a northeast-southwest "Appalachian" belt of volcanics,
some two hundred kilometers wide, across Florida, through the Gulf of
Mexico to the Campeche region; the northern boundary of this belt is
held, following Applin (1951) to divide Silurian and Ordovician sedi-
mentary rocks from rhyolitic lava, pyroclastic rocks, and granite-diorite.
Bass cites the two basalts mentioned above as part of such a belt.
All this suggests the futility of basing broad conclusions on meager
data.
In central Florida, another group, giving much earlier dates, includes
metabasalts in Volusia County, "granites" or "alaskites" in Lake and
Orange Counties, "granite" and dioritee" in St. Lucie County, and
"metabasalt" in Hillsborough County. Age determinations on this group
range from 226 6 (or 224 3) m.y. through 308 5 m.y. to 480
100(?) m.y. or from Early Triassic or Late Permian through Middle Penn-
sylvanian to Early Cambrian. In two wells volcanic rock overlies meta-
morphic rock types-in St. Lucie County basalt overlies "granite" and
dioritee," and in Hillsborough County rhyolite and welded tuff overlie
metabasaltic agglomerate.
The relation of the basalt overlain by unaltered Upper Jurassic or
Lower Cretaceous sediments (Applin and Applin, 1965) in St. Lucie
County to the "granite" and dioritee" just below is an unsolved
problem. Is the basalt a flow over a granite-diorite floor? The age of the
basalt, which is similar in general appearance to other presumably Meso-
zoic southeastern basalts, has been determined (89.3 2.2 m.y. = Late
Cretaceous), but the underlying "granite" has been dated as Early Tri-
assic and the dioritee" as Early-Middle Pennsylvanian (Table 2). These
two disparate ages, however, may reflect decreasing thermal metamor-
phism downward from a basalt flow, with correspondingly diminished
argon loss as demonstrated by Westcott (1966). Differential argon loss
due to the degree of alteration of the dated specimens also could cause
the variation in ages.





Table 2.-Isotope dating of Florida (and Georgia) rocks.


Vol. of
Radiogenic
K20 Argon-40
%, (nmm:;l/ of
sample)


7 Age
Atmos. and
Contam. Error
(m.y.)


24 Highlands County, Florida
Humble Oil and Refining Co.
No. 1 G. C. Carlton Estate




26 Hardee County, Florida
Humble Oil and Refining Co.
No. 1 B. T. Keen

19 St. Lucie County, Florida
Amerada Petroleum Co.
No. 2 Cowles Magazine


12,664 0.308 0.007 1.96 X 10-3


19.0 183 10 RG-I. Rock is very fined-grained. holocrystalline
hasalt, with rare phenocrysts of plagioclase. Con-
tains 60 percent fresh feldspar, 25 percent cloudy
clinopyroxene, and 15 percent olive-green-brown
serpentine after olivine(?). Slightly altered.
Whole rock. Grasty.


11,853 3.49 0.05 1.71 X 10-2 8.2 143 7 RG-2. Very fine-grained basalt which has suf-
1.77 X 102 11.2 147 3 fered low-grade metamorphism with no fresh
feldspar and all mafic minerals chloritized.
Highly altered. Whole rock. Grasty.


12,734 2.085 0.048 3.59 X 10-2


12,744


12,744-8
12,748


39.4 89.3 2.2 Basalt, dark-gray granular rock with calcite
blebs up to several millimeters across. Dia-
basic texture; mostly plagioclase laths with
large olivines completely replaced by bluish-
green chlorite and ore grains. Some calcite re-
placing pyroxene(?). Whole rock. Grasty.
399 Chloritized biotite K-Ar Bass
148 Plagioclase
530 Chloritized biotite Rb/Sr
470 Hornblende K-Ar


12,744 2.29 0.01 1.79 X 10-2 13.5 226 + 6 RG-8. Rock has acid composition and granite
1.80 X 10-2 10.3 224 t 3 texture with 10 percent quartz, 30 percent bio-
tite, and 30 percent plagioclase of which 30-50
percent has been altered to sericite. Biotite shows
slight alteration to chlorite. Quite altered. Whole
rock. Grasty.
12,748 1.24 0.01 1.38 X 10-2 10.4 308 i 5 RG-9. Diorite with 20 percent quartz, 30
percent brown-green hornblende, 10 percent
pale brown biotite associated with horn-
blende, and 30 percent fresh plagioclase. Rock
is fresh. Whole rock. Grasty.


No.
(Table 1)


Location
Operator
Well


Depth of
Sample
(ft)


Remarks









Table 2. (Cotntinued)


Vol. of
Radinogcniu
K2() Argon-1
m', (m3/g pl
sample)


Age
Atoills. arld
Contain. Error
(cl.cU.)


20(1 (O)cc a Ci.(..ntl lFloridal
Hliumli Oil and cHfinicig Co.
No. 1 Hfaynima





21 Ostola Count),. Floridat
Hunimbl Oil .and 1Rfinini C(o.
Carrccll No. 1
15 Volisia Countv, Florida
Sun ()il Co.
No. 1 P'o'll L.and Co.


Mitchliel County. Georgia
Stanolind Oil and Gas Co.
No. 1. J. H. Pullen


8,781 5.32 -0.01 3.19X 10-


.,9.53-.5,95 1







5,955.5-5. ,95S
5,951-5,955


.5,95.5.5-5,9.5


7,375 0.558 o.010 .56i X 1lo-:


18.6 17:3 l(G;- 11. lihyolitic ttl' with very fine-graimed
Matrix probably of quartz and feldspar. (on-
lains rounded crystals. \.nocrasts or frag-
lmnt, of (%\r. conlllll)on quartz, (commnonl al-
tcred alkalic feldspar, and (rari ) plagioclase
alnd rock fragments of( slightly alerted bas.all.
Whole rock. (;rasl.
53;0 Felhispar Rh/Sr Bass



K2(). 0.93 )percent. K41 ppm ).93. Ar-41 p)pm
0.03:2. r.icltmo nic Ar4" 92 percent. Ar40/K40
0.032.5. Age 180I m.%. (Age ma hei los Icn 20
prcentcct or mort because (of variable argon re-
tenltivity of K-lwaering mineral. o'f sample., 11.
Thoma's. H. Marn in. P. Elimore. and H. Smitlh,
analysts, US(;S.
6:31 1lornfels biolile Hb/Sr Bass
159 Hlornblend( indiorite K-A.r Bass
c 12 P'laioclas,
524 Hiotite indioritc hornfils K-Ar Bass
:39:3 lornblendcnd ndiorite hornfels K-Ar Bass

17.5 182 5 H(G-3. Dialas sho\ ing typical dark aiglitic
pyrox\enil, and light iplialgoclase fci'(spar. Holo-
crystalline, frc e of alteration. Very fresh rock.
\'holc rock. G(ratly.


No.
(Table 1)


Location
0()f)rator
\V'.ll


Depth qof
Sampll
(ft)


HRioark.




Table 2. (Continued)


Vol. of
Radiogenic
K20 Argon-40
(% (unml3lg of
sample)


'7 Age
Atmos. and
Contain. Error
(m.y.)


Echols County, Georgia
Hunt Oil Co.
No. 2 Superior Pines















Chattahoochee County,
Georgia
Cusseta (water well)


4,130 0.813 0.037 5.42X 10 :

















1,200-1,205 0.43 0.007 4.69 X 10-3


61.7 191 15


HG-5. Rock chips from same rock type but
with one fine-grained phase and one medium-
grained phase. May he from chilled margin and
coarser grained interior of either dike or flow
or, more likely, a basalt and a diabase. Fine-
grained phase has 20 percent plagioclase phe-
nocrysts in matrix of very-fine grained
opaques and pyroxene (?) with needles of pla-
gioclase and some iddingsite after olivine (?).
This phase is slightly altered. The medium-
grained phase has a diabasic texture with 30
percent fresh plagioclase, 40 percent augite,
and 10 percent interstitial iddingsite after
olivine (?). Opaques occur as accessories. This
rock is slightly altered, with 10-20 percent
material which is probably devitrified glass.
Whole rock. Grasty.


67.5 303 15 RG-6. Hornblendite consisting essentially of
Slue-green hornblende, clear quartz, cloudy al-
kalic feldspar, brown biotite, and pale-green
chlorite. Rock was run as hornblende separate
of 70-120 mesh. Whole rock. Grasty.


Table 2a. Age determinations Amerada Petroleum Corp. Cowles Magazine No. 1


Sample
Depth Material


127:34 Basalt Grast)
1274 Granite

Chloritized biotite from schist Bass
and quartz diorite gneiss


Plagioclase from quartz diorite
gneiss
12748' Diorite
Hornblende in diorite (amplhio-
lite)


Grasty
Bass


Analyst Method Age


K-Ar 89.3:2 m.y.
226 6 inm..
224 i-3 m.y.

Sr /Sr 86 53i ni.y.

K-Ar 399 m.y.
148 m.y.

308 5 m.y.
470 m.y.
503 m.y.


No.
(Table 1)


Location
Operator
Well


Depth of
Sample
(ft)


Hemarks







BUREAU OF GEOLOGY


Another question is whether the "granites" of Florida are really gran-
ites, or arkose altered by contact metamorphism. Altered sedimentary
rocks are well known in regions of Triassic volcanism in many localities
in the eastern United States; they are associated with major tectonic
disturbances that exposed large volumes of granitic rocks both to rapid
erosion, and, in places, to hydrothermal alteration. The "granite" in
the Pierce County, Georgia, Adams McCaskill wells (Milton and Hurst,
1965) may have such a history. Further, granophyres of superficially
granitic aspect and composition are well known as differentiates of large
diabase bodies, and many of the so-called "basement granites" in Georgia
strongly suggest a granophyric origin (e.g., Glynn County, Georgia,
Humble Oil and Refining Co. No. 1 W. C. McDonald).
No unambiguously metamorphic rocks-such as mica schist, garnet
schist, chlorite-kyanite-sillimanite schist, or marble-have been found
in Florida. The rocks termed "granite" or dioritee" may be contact-
metamorphosed sedimentary rocks, or thermally altered phases of
igneous intrusives. Whether or not drilling in Florida has penetrated a
truly metamorphic basement of Precambrian or even early Paleozoic
age is, in our opinion, still an open question.


DATING OF FLORIDA AND GEORGIA
IGNEOUS-METAMORPHIC ROCKS

The K-Ar dates in Table 2 were determined at the University of Tor-
onto by Robert Grasty and M. N. Bass (1969), with the exception of
that for the Volusia County, Florida, hornblende diorite or metabasalt,
which was determined at the U. S. Geological Survey. For the rocks
dated by Grasty, duplicate potassium determinations were made on each
sample, with lithium as an internal standard and sodium as a buffer.
Argon, extracted in a bakable glass fusion system, was mixed with
"spike" argon-38 and analyzed by an MS 10 mass spectrometer, as
described by Farrar et al. (1964). Six measurements of the argon-isotope
ratios were made on each gas sample. The limits of error are standard
deviations deduced from the errors in both the potassium and argon
measurements. In the University of Toronto laboratory, the standard
deviation of repeated measurements on the same sample is generally less
than 2 percent and analyses of interlaboratory standard samples show
that systematic errors are also less than 2 percent (Baksi et al., 1967, p.
6306). Repeat measurement on RG-2 and RG-8 confirmed this accu-
racy. Constants used in the calculations are XB = 4.72 X 10-10yr-1, xe =
0.584 x 10-10yr-1, K40 = 1.19 X 10-2 atom percent.
The K-Ar ages range from Late Cretaceous to Early Ordovician or
Early(?) Cambrian. Except for the youngest and the three oldest, the ages





BULLETIN NO. 55


are within a range from Late Jurassic to Early Triassic. The two dates
(middle Carboniferous) for homblendite from Chattahoochee County,
Georgia, and diorite from St. Lucie County, Florida, are similar to dates
from late Paleozoic volcanic rocks recognized elsewhere in the Appala-
chians.
The youngest age whether or not valid, 89.3 + 2.2 m.y., is by no means
the youngest to be reported in the Applachian region; Fullagar and Bottino
(1968) give a Tertiary age (30 15 m.y.) for felsite from HighlandCounty,
Virginia.
The oldest age, 480 +- 100(?) m.y. (or 524 m.y.) from Volusia County,
Florida, "metabasalt," is within the range of the Cambrian to Ordovician
age of the North Carolina "Slate Belt" rhyolites determined by Hills and
Butler (1968). Some workers have referred the Georgia-Florida volcanic
rocks in part to the "Slate Belt" series. Three ages obtained by Bass (1969)
on samples from Humble Oil and Refining Co., No. 1 Carroll, Osceola
County, Sun Oil Co., No. 1 Powell Land Co., Volusia County, and Amerada
Petroleum Corp. No. 2 Cowles Magazine Inc., St. Lucie County, are re-
spectively, 530, 524, 530+ m.y. These determinations indicate a Middle
Cambrian age.
The K-Ar and Rb/Sr dates of Bass (1969) cited in Table 2 are discussed
in detail in his paper.


CHEMICAL ANALYSES OF FLORIDA
IGNEOUS-METAMORPHIC ROCKS

Table 3 gives the chemical composition of 11 Florida igneous-metamor-
phic rocks. Because these results are from small and generally isolated spec-
imens, their present value is limited; however, as more information on the
Florida subsurface becomes available, comparative studies may be found
useful.
The analyses have been computed in terms of normative minerals, in
Table 3a. This often gives a somewhat clearer picture of what meaning the
analyses may have, although it must be emphasized that the data presently
available is altogether insufficient for any meaningful generalizations.
To illustrate this we may compare the analyses or rather the norms, 9 and
11, or volcanic ash and rhyolite, respecitvely, from Putnam County and
Hillsborough County, 150 miles apart. The two norms are indeed similar
- high normative quartz, substantial normative corundum orthoclase, and
albite plagioclase; normative hematite and magnesite. It would appear that
these two rocks are part of one body. Yet a second specimen of the Hills-
borough County rock, analysis 10, unquestionably from the same body,
shows neither normative quartz nor corundum, strongly calcic plagioclase,
much, not little, mafic minerals, and neither hematite nor magnesite.
Again, the two very similar analyses of diabase, 5 and 6 from Taylor







Table 3. Chemical Analyses of Florida Igneous-Metamorphic Rocks' '

1 2 3 4 5 6 7 8 9 10 11

SiO2 63.7 46.8 68.7 57.0 50.9 52.8 51.7 57.1 73.3 48.3 59.1
A1203 15.1 17.1 15.4 16.8 16.6 15.3 17.3 13.9 13.8 11.0 13.0
Fe20)3 3.3 3.5 .74 3.0 4.3 2.2 10.2 4.1 2.5 :3.1 3.8
FeO 2.6 6.1 2.6 4.9 4.6 9.9 .72 3.4 .51 5.7 1.2
MgO 3.3 10.5 :3.0 5.6 6.2 1.4 3.1 7.2 .93 9.2 3.0
CaO 1.1 3.2 3.7 6.8 6.3 8.9 .54 1.3 .02 8.3 4.1
Na2O 3.0 1.2 1.9 1.6 3.3 2.5 1.1 2.7 2.4 1.5 4.3
K20 2.6 3.3 .95 .90 .57 .68 5.5 2.2 3.2 3.1 3.6
H20 .32 .55 .14 .06 2.5 .46 3.5 .37 .13 1.1 .35
H2O+ 2.9 5.4 2.1 1.9 1.9 1.1 3.6 2.1 1.7 2.9 .15
T102 .62 .8.3 .45 .75 1.2 1.1 1.2 .73 .32 .94 .32
P20s .20 .12 .28 .28 .17 .17 .36 .22 .08 .16 .04
MnO .11 .11 .07 .17 .08 .22 .07 .14 .03 .19 .23
CO2 .75 .52 <.05 < .05 .46 <.05 .15 .45 <.05 .95 6.1
Sum2 100. 99. 100. 100. 100. 100. 99. 9 9. 9. 99. 99.
Powder density by
sink float 2.72 2.72 2.72 2.80 2.60 2.95 2.52 2.80 2.72 2.80 2.70

SAnalyses by Paul Elmore, L. Artig, S. Botts, G. Chloe, H. Smith. J. Kelsey, and J. Glenn, U. S. Geological Survey, using methods described by
Shapiro and Brannock (1962), supplemented by atomic absorption techniques.
2 Rounded to nearest whole number
3 For location, lab. no., and remarks see below.

Well
Analysis Locality Lab. No. Remarks
No. (Fig. 1)


21 W168611


19 W168612



19 W168613
19 W168614
5 W168615
5 W168616


Osceola County, Florida; Humble Oil and Refining Co. No. 1 Ray Carroll; 8,034-8,042 ft. "Al-
tered and veined biotite granite" (F. F. Grout in Applin, 1951). Possibly hydrothermally
altered arkose (C. M.) (Fig. 2c).
St. Lucie County, Florida, Amerada Petroleum Co. No. 2 Cowles Magazine, amygdaloidal ba-
salt, 12,734 ft. dated 89.3 2.2 m.y. (Fig. 2d).


"Granite," 12,744 ft. dated 226 6 m.y. 224 -3 m.y. (Fig. 3a).
"Diorite," 12,748 ft. dated 308 5 m.y. (Fig. 3b).
Taylor County, Florida. Humble Oil and Refining Co. No. 1 G. H. Hodges, 6,162 ft. diabase.
Diabase, 6.216-6.219 ft.





Table 3. (Continued)


Anallyis Iocality Lah. No. Remarks
No. (Fig I)



7 15 WI68fil7 Volusia County. Florida. Sun Oil Co. No. I Powell Land Co.. 5,919-5.922 ft. "weathered"
volcanic rock now clay.

8 10 W\li6Nfil Flagler County. Florida. Ilumble Oil and Refining Co. No. I j. W. Campbell. 1.62 0'.- .626 ft.
Hydrothermally altered basalt and rhyolte tuffT.

9 II W f861(9 'utnam County. Florida. Sun Oil Co. No. I II. E. W\estiury et al. 3,879-3,n8! ft. Volcanic
ash.

10 27 W 1\\ 620 IHillshorough County Florida. Humble Oil and Refining Co. No. I T. S. Jameson. IO019-10.022
ft. Hhyolite or welded tuff.

11 27 \VWfi621 Rhyolite, 10.115i-10.125 It.

Table 3a. Florida igneous-metamnorphic rock norms


1 22
3)9.9 9 3.18H9
7.351 7.228
I5..6(i 19.501l
25. 183 101.1. I
11.8011

1h,(16 26i.150
1.229 7.I 11


Ap.aite .171 .28I
Cal ite 1. 19 I. I I
M%.il site .179 -

Snlic 79.019 5.1,875
FImiic 17.312 11. 112

9(6i.92* 9.3.2N7
lhis and other totals a;re c onlputer figures.
T1hi norm has beiin ctliolputed with .ON', I'2o() a;td


1 .1
40.923 19.709
5.305 1.617
5.f61 5.318
16.077 1 .539
16.21(0 11.589

7.172 1 1.917
3.530 5.597


.5
7,121
.573
1. 6N8
27.921
27.2 16

15. 11
1.0(62


6 7
6.901 183.022
9.0 1 I
1.018 12.501
21.151 1 I.N16
28.517
5.933
10.958 7.1I96
14.955


1.07:3 1.350 6.235 3. 190

.855 1.121 2.279 2.089

.66( 3 .6 .3 .103 .103
.11 .11 1 1.0 16 .114


81.129 71.771 66.221 (60.591
1:3.726 236,095 28, 165 37.611

97..55 97.66( 9 1.690 98.231


10.200
1.i70
1211
.N5 I
.INN
.188

71. 113
20.M 16

92.2594


13.01100
22.817
17.450

17.9312
1.911


5.915

1. 186

.521
1.021


67.735
28,718

96. 153


9"0 10


18.91(0 Is. 19
20. 10S 12.6193
22. i12

2.202 1 .512
5.711
2. 38
.769
.911 1. 195
I.872 -
.(60 1.785

179T
2.1il1
.096 -

91.382 53.32:3
5.688 12.127

97.070 95.151


11
19.S32
2.030
21.273
36.385


.802



3.691
1.255.
.fiON

.095
7.221
5.612

79.520
19.275

98.795


.02'; CaO. ati h reduced to .IMI',. lo conforn with thi t oiiputer program.


Qu,)aIirtz
Corunldum
Orthotlase
Albite
Anorthite
\Wollastonite
Enist.tite
Ferrosilite
Forsterite
IFyiilite
Mlagnetitr
Henmatite
Ilinenit,
Hulltl.


1.785

1.17S


5.075

1.576







BUREAU OF GEOLOGY


County, referred to above (pages nmm...) do show definite difference
from the St. Lucie County amygdaloidal basalt, some 250 miles distant;
first being presumably Triassic-Jurassic, the second dated as much
younger, namely upper Cretaceous (89.3 m.y., Table 2). However, com-
paring all three analyses of the St. Lucie County rocks, while the three an-
alyses (2, 3, 4) are remarkably similar, their isotopic ages are widely dis-
parate.
Thus we may conclude by observing that the value of these analyses is
for the present limited to what they may contribute to the understanding of
the individual rock specimen, and that attempts to use them for broad cor-
relative purposes are futile.


DESCRIPTIONS OF
FLORIDA "BASEMENT" ROCKS

NASSAU COUNTY
ST. MARY'S RIVER OIL CORP.
HILLIARD TURPENTINE CO. NO. 1 4824' T.D.
Completed 1940 Well locality 1 Applin (1951) No. 67
Triassic diabase in Paleozoic shale
Cole (1944) reports that this well was begun in 1936, and completed
eight years later at a depth of 4817 feet. He briefly reviewed earlier ac-
counts by Campbell, Schuchert, and Munyon, and discussed extensively
the micropaleontology of the well. He also considered in detail the non-
fossiliferous rocks, below the marine sediments (Upper Cretaceous Tus-
caloosa).
Below the Tuscaloosa, which in this well consists of 380 feet of gray,
hard, calcareous and glauconitic sandy shale, with shark's teeth, is 155 feet
of dark gray, hard shale, devoid of fossils, followed by diabase to the bot-
tom of the well. Applin (1951) states that the diabase underlies Paleozoic
black shale, later confirmed by paleontologic studies by J. Bridge and J.
Berdan.
Cole, after considering all the evidence, observed, "It is the opinion of
the writer that the section from 4640 to I7'>, (the 155 feet of unfossili-
ferous shale) represents a non-marine phase and that the age of the rocks
is Triassic. The writer believes that they are equivalent to the Newark ser-
ies." As for the diabase which intrudes the shale, a study by T. Osborn
Fuller, cited at length by Cole, convinced him that it is of Newark (Tri-
assic) age.
Nevertheless, Applin (1948) referred to the published data as "conflict-
ing and inconclusive" but correctly included the well as among those which
entered "Paleozoic black shale."
Berdan (written communication, May, 1970) states that "a sample of






BULLETIN NO. 55


rather large chips of dark gray shale from a depth of 4700-4800 feet con-
tains a small fragment of eurypterid integument which shows the charac-
teristic scales of the genus Pterygotus. This genus ranges from the Ordovi-
cian into the Devonian. However, a core of dark gray shale from Sun Oil
Company J. H. Tillis No. 1 well in Suwannee County also contains Ptery-
gotus, which was considered to be Silurian in age by Kjelleswig-Waering
(Jour. Paleont., v. 24, no. 2, p. 229-231, 1950), who described it as P.flor-
idanus. It seems probable that the shale in the Hilliard well is correlative
with that in the Tillis well, and is also Silurian."
Two thin sections of the diabase, one from 4818'-4819', the other 4823'
are both fresh unaltered diabase; the lower one is somewhat more fine
grained.



COLUMBIA COUNTY
HUMBLE OIL AND REFINING CO.
J. P. CONE NO. 1 4444' T.D.
Completed 1949 Well locality 2 Applin (1951) No. 42
Diabase in Paleozoic shale
Applin (1951) lists six occurrences of diabase and amygdular basalt
sills in black shale of Paleozoic age at
3529'-3562' 4193'-4195'
3564'-3565' 124'"-4251'
4191'-4192' 4267'-4270'
Cores are available from 3520' to 4281'.
Core 115 3520'-3529' recovery 8'
Top 7' is gray carbonaceous (burns white) shale, with pyrite and a
little sphalerite along bedding planes. Microscopically the shale is seen to
contain innumerable clear colorless sericitic grains, with rectangular or
hexagonal cross section (Figure 1). Most show concentration of the dusty
shaly matrix material in the interior of the grain, with clear borders; this
suggests that the grains may be sericitized andalusite, in which such seg-
regation is normal.
Bottom 1' is at the contact of black shale and underlying diabase. It is
a light colored fine grained rock with calcite layers and numerous small
rounded pyrite nodules. In thin section (Figure 2) the rock is seen to
consist almost wholly ofplagioclase laths and calcite (replacing augite?) and
pyrite (replacing iron-titanium oxide?).
Core 119 3541'-3543' top part of core is hard fresh diabase.
Core 120 3543'-3555' top part of core.
This is a perfectly normal diabase, with typical mineralogy calcic
plagioclase laths and subhedral augite; with minor black ilmenite grains
and greenish chlorite (Figure 3).






BUREAU OF GEOLOGY


Altered diabase
Figure 2. Columbia County, Florida, Humble Oil and Refining Company J. P. Cone
No. 1, 3520'-3529'. Bottom foot of core.
Shows (white) plagioclase feldspar. The dark areas represent mostly cal-
cite (replacement of pyroxene?) and (most of large black aggregate left of
center) pyrite, which may have replaced ilmenite-magnetite. Ordinary light,
X28.5.

Core 121 3555'-3562' top and bottom of core, hard fresh fine
grained diabase. No different from preceding.
Core 122 3562'-3589' Sample from second 10 ft. of core. Greenish
gray shale with calcite-pyrite layers; also red heulandite(?). Orthoconic
cephalopods occur in this shale (Roland Brown, J. M. Berdan, U.S.G.S.).
Core 149 4181'-4206' Sample from bottom of core, amygdaloidal
basalt. This is a fine grained gray-green vesicular rock, with blebs of coarse
white calcite up to an inch across; some of the smaller ones are reddish in
part. There are also small pyritic segregations.







BULLETIN NO. 55


tilb
",

"'4 3j~~


t. .
-C 4


'" -'** .< ^ *
kA R.'


Diabase
Figure 3. Columbia County, Florida, Humble Oil and Refining Company J. P. Cone
No. 1, 3543'-3555'. Top part of core.
Normal diabase, with typical laths of calcic plagioclase and euhedral
augite between the feldspars. Ordinary light, X28.5.

In thin section, the rock shows a poorly crystallized dark turbid ground-
mass, in which are strewn in abundance small colorless or faintly reddish
augites. A few of these are larger than the others, and consist of interpene-
trating twins of several individuals. Iddingsitized (?) euhedral olivines
are small but numerous. The more definitely colored augites are reddish-
violet, show axial dispersion and are probably titaniferous. The calcite
segregations often show an irregular peripheral zone of brown substance,
perhaps serpentine, and some have spherulitic development (Figures 4
and 5).
Core 151 4231'-4256' middle third, gray amygdular basaltic rock,
with irregular calcitic amygdules.


** ;?'


P' da8:"'
--. ...







BUREAU OF GEOLOGY


Amygdular basalt
Figure 4. Columbia County, Florida, Humble Oil and Refining Company J. P. Cone
No. 1, 4181'-4206' Sample from bottom of core.
Amygdular basalt; at the lower right is a large amygdule of radially fi-
brous calcite, at the upper right, a similar amygdule with olive brown ser-
pentine and calcite. The crystals in the basalt are mostly serpentinized oliv-
ine and unaltered augite. Ordinary light, X14.

Core 152 4256'-4281' Sample from middle of core. Recovery 24'
"1 ft. of core is like material submitted, remainder is black shale" Louise
Jordan (Sun Co. geologist, now deceased).
The sample of the 1' zone consists of two somewhat different rocks, one
in contact with black slaty shale. The contact phase, about one inch wide,
is light gray-green, markedly pyritic and vesicular; it grades into a darker
more uniformly-textured rock, like the second specimen, which, however,







BULLETIN NO. 55


4 x2t~ *I.,
4.44


Basalt-calcite (hydrothermal) contact
Figure 5. Columbia County, Florida, Humble Oil and Refining Company J. P. Cone
No. 1, 4181'-4206'. Sample from bottom part of core.
Shows contact of basalt and coarse (hydrothermal) calcite. Near the center
is a mass of calcite partly enclosed by olive-brown serpentine. (The clear
area is where the section broke apart during grinding.) Crossed nicols, X14.


also shows scattered pyritic-calcite amygdules. In thin section, the contact
shows a poorly crystallized turbid '.r -I I., with small poorly-developed
plagioclase crystals, and no well-developed augite. There are large ill-
defined light colored areas, with skeletal magnetite and thin laths of brown
hornblende. Often the middle of these areas is calcitic. (Figure 6). The
darker rock, however, away from the contact, is well crystallized, and
consists largely of reddish-violet tinted augite in stubby prisms, some
larger than the others. There are also chloritized olivines, and inconspic-
Uous poorly-developed feldspar in the groundmass. The few large calcite







BUREAU OF GEOLOGY


Amygdular basalt
Figure 6. Columbia County, Florida, Humble Oil and Refining Company J. P.
Cone No. 1, 4256'-4281'. Sample from middle of core. Ordinary light, X14.




vesicles contain euhedral pyrite and are associated with a colorless iso-
tropic mineral, possibly analcite.
In this well basalt-diabase sills are found from 3529' to 4281', or through
about 750 feet. The sills are intruded into 962 feet of fossiliferous black
shale considered to be Late Silurian or Early Devonian in age (Berdan
and Bridge, 1951, p. 69). The association of typical diabase with typi-
cal basalt suggests that the two rock types reflect differences of physical
conditions under which these bodies crystallized, from a common mag-
matic source.







BULLETIN NO. 55


MADISON COUNTY
HUNT OIL COMPANY
J. W. GIBSON NO. 2 5385' T.D.
Completed 1945 Well locality 3 Applin (1951) No. 62
Diabase in Paleozoic shale
Igneous rock was not noted by Applin (1951) but cuttings from ,"i'-
5210' are greenish granular diabasic rock. It appears to be weathered,
but microscopic examination indicates hydrothermal alteration rather
than weathering. Calcite and bright green chlorite are abundant; very
little feldspar remains, it being replaced by fine grained serpentinic or
chloritic material. Black magnetite grains are numerous. Figure 7 shows
the microscopic aspect of this rock.


~,
"' i*-~:


~~~?t%"r


I.. :4 .'.'
''i 8'0 :
.% 5-'vU.


Y'u

K 'x:~~t"


Diabase (hydrothermally altered)
Figure 7. Hunt Oil Company J. W. Gibson No. 2, Madison County, Florida, 5200'-
5210' (cuttings).
This is volcanic rock, still showing original texture though the constituent
minerals have been altered considerably. Ordinary light, X28.





BUREAU OF GEOLOGY


The rock is a hydrothermally altered diabase. A core above it, at the
depth of 5154-5162 feet, is dark gray shale containing the trilobite Colpo-
coryphe exsul Whittington, 1953, which is considered late Early or early
Middle Ordovician in age (Berdan, 1970, written communication).


TAYLOR COUNTY
GULF OIL COMPANY
BROOKS SCANLON BLK. 42, NO. 1 5517' T.D.
Completed 1949 Well locality 4 Applin (1951) No. 82
Diabase-basalt
"5438'-5517' T.D. is diabase, probably a lava flow. Underlies elastic
rocks of Triassic (?) or Jurassic (?) ages." Applin (1951)
Specimens from Core 39 5448'-5453' (recovery 2 ft.) to Core 43 5512'-
5517' T.D. (4 ft. recovered, top) were studied. All are of very similar rock,
namely brown basalt with conspicuous green serpentinic material. Zeoli-
tization (red heulandite?) is locally conspicuous.
In thin section Core 43, 5512'-5517' T.D. (sample from bottom of
core), it is seen to have the characteristic texture of a basalt or diabase;
the calcic plagioclase feldspars and augite remain little altered, but the
larger crystals of olivine have been completely replaced by iron oxide and
iddingsitic material (Figure 8).







BULLETIN NO. 55


Figure 8. Gulf Oil Company Brooks-Scanlon Blk. 42, No. 1, Taylor County, Florida,
5512'-5517' (bottom of core).
Olivine (?) diabase. The black areas are limonitic replacements of olivine
(?) which is also represented by olive-brown serpentinic areas. Calcic
plagioclase and augite are fairly unaltered. Ordinary light, X22.

TAYLOR COUNTY
HUMBLE OIL AND REFINING CO.
HODGES NO. 1 6254'T.D.
Completed 1948 Well locality 5 Applin (1951) No. 83
Diabase-basalt
Applin (1951) states that this "well terminated in diabase gabbro. Un-
derlies early Mesozoic plastic rocks" and "6153'-6165' basaltic rocks; un-
derlies elastic rocks of Triassic (?) or Jurassic (?) age. 6165'-6254' T.D.
diabase gabbro."
Core samples are available representing some 96 feet of igneous rock,
from 6153'/ to 6249', all igneous rock.







BUREAU OF GEOLOGY


The upper ten or twelve feet of the volcanic rock differs from the
eighty-five feet of volcanic rock drilled below. The upper zone is highly
calcitic, with abundant calcite veins, micro-breccia, and other evidence
of possible contamination by ingested limestone. The lower zone is nor-
mal diabase. In detail:
Core 111 6151'-61' recovery 71', sample at 6153!2'
This is a light gray granular volcanic rock, cut by a vertical vein of cal-
cite, a quarter of an inch wide. (Fig. 9)
Gray or green volcanic rock, sample at 6155', and another core frag-
ment, somewhat coarser, with abundant oligoclase-andesine, are almost
completely chloritized and calcitized mafics. (Fig 10)
6156' calcitic agglomerate
6159'-60' gray green volcanic, with calcite veins


Figure 9. Humble Oil and Refining Co., Hodges No. 1, 6153;2', Taylor County,
Florida.
Basalt with calcite contact (?); somewhat calcitized basalt-diabase on
left, fine grained calcite on right. Ordinary light, X22.







BULLETIN NO. 55


Core 112 6161'-6.2' recovery 1' sample at top gray green volcanic
Core 113 6162'-80' recovery 18', sample at 6162' top gray green
volcanic agglomerate, with pyrite and calcite veins.
at 6162' bottom gray volcanic rock, chloritized mafics but feldspars
(oligoclase-andesine) perfectly fresh. Some fresh brown biotite. Calcite
veins. Texture rather coarse, grading into diabase.
This rock has been analyzed (Tables 3 and 3a, No. 5)
at 6165,2' gray volcanic rock, highly calcareous, probably a volcanic
breccia. (Fig. 11)
at 6167' coarse diabase
at 6175' coarse diabase


Figure 10. Humble Oil and Refining Co., Hodges No. 1, 6155', Taylor County, Florida.
Basalt-diabase. The pyroxenes, etc. are completely calcitized, but the
plagioclase feldspar is unaltered. Ordinary light, X22.5.








BUREAU OF GEOLOGY


S-J

Figure 11. Humble Oil and Refining Co., Hodges No. 1, 616533', Taylor County, Flor-
ida.
Calcitic explosion breccia? The rock consists of a calcite matrix with
rounded fine grained ash (?) and chloritic debris, as well as coarse fresh
angular particles of pyroxene, calcic plagioclase, highly altered biotite
and micro-pegmatite. Most of the lighter area in the figure is calcite; sev-
eral rounded ash (?) grains are shown. Ordinary light, X17.








BULLETIN NO. 55


Figure 12. Humble Oil and Refining Co., Hodges No. 1, 6216'-6219', Taylor County,
Florida.
Coarse fresh normal diabase, completely unaltered. Ordinary light, X17.


Core 115 6204'-6219'
at 6216'-19' diabase, no chlorite or calcite in thin section; a per-
fectly fresh normal diabase. (Fig. 12) This rock has been analyzed (Tables
3 and 3a, No. 6)
Core 116 6229'-6254'
at 6246'-49' diabase, with pyrite along cracks.
The two rock analyses are in general quite similar, as might be expected,
both being of diabase; however, the first shows both more oxidation of
iron and considerably more water especially H20-.


:
~L~4~
ti
i..






BUREAU OF GEOLOGY


JEFFERSON COUNTY
COASTAL PETROLEUM CO.
E. P. LARSH NO. 1 7913' T.D.
Completed 1949 Well Locality 6 Applin (1951) No. 54
"Diabase and related kinds of volcanic rocks (7763'-7792' and 7850'-
7890'). Sills or dikes in elastic rocks of Triassic (?) age."
Applin (1951)
Samples (cores and cuttings) were examined from 7650' to 7913', in-
cluding the two igneous intrusives.
They are as follows:
7650'-7660' cuttings mostly red sandstone; no igneous rock.
7680'-7690' cuttings red and gray sandstone; no igneous rock.
7690'-7700' cuttings much diabase with red and gray sandstone.
This indicates a third sill or dike, besides the two indicated above.
7720'-7730' cuttings These are fresh unweathered diabase.
7760'-7770' cuttings diabase
7789'-7791' core (1 ft. recovered). This is fresh unweathered diabase,
similar to that from 7720'-7730', but somewhat finer grained. Figure
13 shows the typical diabasic micro-structure of this rock.
Another sample from this depth is cuttings, containing much diabase.







BULLETIN NO. 55


Diabase
Figure 13. Coastal Petroleum Company, E. P. Larsh No. 1, Jefferson County, Florida,
7789'-7791'.
This shows the characteristic texture ("ophitic") and mineralogy (essen-
tially augite, calcic plagioclase and ilmenite). The rock is practically un-
altered, the only replacement being of olivine (?) by chloritic or ser-
pentinic material. Crossed nicols, X28.







BUREAU OF GEOLOGY


7791'-7795' core (3 ft. recovered). Top foot this is a very fine
grained gray micro-porphyritic basaltic rock, showing some alteration -
calcitization and chloritization. It is illustrated in Figure 14. This abrupt
change in texture and composition within a few feet indicates that a given
magma may crystallize either as basalt or diabase in response to very lo-
cal conditions; and that correlations based on one or the other type of rock
are likely to lead to error. Below this, only sedimentary rock was found.
middlefoot. This is a shaly sandstone.
bottom foot. This is similar to the preceding, with less quartz. It may
be baked shale (Fig. 15).


Calcitized basalt
Figure 14. Coastal Petroleum Company, E. P. Larsh No. 1, Jefferson County, Florida,
7791'-7795'.
Although the plagioclase feldspars are unaltered, the mafic minerals
of the basalt are replaced by calcitic material. Ordinary light, X 28.







BULLETIN NO. 55


Baked shale (?)
Figure 15. Coastal Petroleum Company, E. P. Larsh No. 1, Jefferson County, Florida,
7791'-7795'.
Shows angular quartz particles in very fine grained dark crystalline
matrix. Ordinary light, X 28.

7909'-7911' (1,' recovery) This is a whitish sandstone, almost wholly
quartz, with strong evidence of recrystallization almost all the quartz
grains show peripheral secondary growth, and clay is recrystallized to seri-
cite. There is also green tourmaline, in minute grains, also probably auth-
igenic (Fig. 16 a, b).
7911'-7913' (1' ft. recovery) Sample from bottom 1 ft. 10 in. of core.
Two different specimens: One is hard rather coarse sandstone, light col-
ored; the matrix of the quartz grains however is well recrystallized into
pale green chlorite. The other specimen is rounded pebbles (1 cm. across)
of red very fine grained shale, possibly volcanic ash.











v ;
'S



,."*7

.6.

*~', "**'
-s

e : '*


4.


1rtP'V~ .4 t(

"S9~


* t


A '



A


Vt. -


Ft


0 5 mi!
L _. .. Ji


At.~


Figures 16 a, b.


Sandstone

Coastal Petroleum Company, E. P. Larsh No. 1, Jefferson County, Florida, 7909'-7911'.
This shows features which may perhaps be related to thermal metamorphism. Many of the quartz grains show second-
ary enlargement, the original detrital grains being outlined by the dark rims seen in the illustrations, with new quartz


I .


2

p .

%~,-


0. .'

I S5 mm
! -- I


\

^


- V
*^'






BULLETIN NO. 55


In summary, a series of sandstones and shales was intruded by diabase
or related rock at (or not far above) 7690', 7720'-7730', and again at
7789'-91', 7791'-95'. Below this to 7913' T.D. there are indications of
volcanic activity, but no specimens of actual volcanic rock.

FRANKLIN COUNTY
CALIFORNIA CO. AND COASTAL PETROLEUM CO., NO. 2
Well locality 7
State Lease 224a. Latitude 29047'03" N Longitude 84'22'51" W
South Shoal area about 13 miles offshore from Carrabelle, Florida T.D.
10566' (driller), 10507' (electric log). Completed 1961.
This well drilled into 10 feet of diabase at 10460 ft. (Data from P. L.
Applin, written communication 1967).
Specimens are available as follows:
10318-19 10324-25
10320-21 *10325-26
10321-22 10326-27
10322-23 10327-28
10323-24 *10328-3212
These are all pinkish quartzitic sandstone (cored), well-indurated some
with white clayey specks. Figure 17 illustrates 10325'-10326'. The Sand-
stone from 10328'-1033212' contains much calcite.
S10460-70 10510-20
10470-80 *10520-30 (Figure 18, basalt-diabase). Figure19 baked shale.
10480-90 10530-40
10490-10500 10540-50
10500-10 10550-60
These all contain diabase fragments, admixed with sandstone.
"Thin sections



JACKSON COUNTY
HUMBLE OIL AND REFINING COMPANY
C. W. TINDEL NO. 1 T.D. '-2 1-,
Completed 1949 Well locality 8 Applin (1951) No. 53
Applin (1951) refers to this as follows:
"8890'-8932' Porphyritic hornblende basalt. A small intrusive or flow in
Paleozoic rocks," with a thickness of 42 feet. However, the overlying sand-
stone 8881'-8891' (top 5'2 feet) is a fine grained reddish sandstone show-
ing structures interpreted as being due to contact metamorphism, indi-
cating an intrusion rather than a surface flow. A specimen from the bottom
632 feet of this core is hard fresh fine grained basalt, showing marked
calcitization.






BUREAU OF GEOLOGY


Six specimens of the core from this well are:
Core 100 8521'-8526' (sic) fine grained red siltstone
Core 120 8737'-8742' fine grained gray siltstone
Both of these are similar to the siltstone specimens below the igneous rock.
Core 130 8881'-8891' (top 5, feet) fine grained light reddish brown
siltstone. It shows disturbance and internal dislocation (fig. 20), and is
interpreted as a mildly contact-metamorphosed siltstone overlying the
intrusive rock, represented by the following specimen.
Core 130 8881'-8891' (bottom 1 ft. of 62 ft. recovery) This is hard
fresh fine grained basalt, strongly calcitized. Abundant calcic plagioclase
is fairly fresh, as is also minor brown hornblende; but large areas in the


7'-.
4.


a-ye


--A


1


I,
I, sy


4'

'fryC


I


~'




.irp& -.s 4,


I .


AtI.


:1' ''- i;
- V:.- ^c

K
..I-^. '
*1 ^''v


4


I'
*'' .d 5



Ac 4
rI
; f ~ -: .^^
*': -u '. '

"*r/ "' ti


- a..


Figure 17. California Co. and Coastal Petroleum Co. No. 2, Franklin County, Florid2
10325'-10326'.
Sandstone with rounded quartz grains showing secondary growth. Wel
crystallized calcite and dickite (?) aggregates occur interstitially. Ordi
nary light, X36.


IS


4


~ -~s
wr ...""?


r i

% e;..





BULLETIN NO. 55


thin section, formerly pyroxene or olivine, are now vague brownish ag-
gregates of calcite, chlorite, and clayey material. Small brownish euhedral
opaque ore grains, with somewhat large masses of pyrite, are fairly
abundant; and quartz filled amygdules are present. Figures 21a, b illus-
trate this rock.
Core 136 8987'-8997' is fine grained red standstone.
Core 141 9232'-9237' is fine grained gray calcareous siltstone, uni-
form in thin section, unlike the siltstone overlying the basalt.
Core 142 9237'-9242' is similar.


0.5 mm" ,

Figure 18. California Co. and Coastal Petroleum Co. No. 2, Franklin County, Florida
10520'-10530'.
Calcitized Basalt. The basalt consists almost wholly of fresh plagioclase
inan obscure matrix largely calcite; with some ilmenite. Ordinary light
X29.







BUREAU OF GEOLOGY


In summary, these four samples indicate that a 42 foot basaltic sill in-
truded a siltstone series in which the well bottomed 313 feet below the
igneous rock, at ''24- T.D. The siltstone contains plant fragments iden-
tified by S. IH. Mamay as Psilophyton s.l., indicative of an Early or Mid-
dle Devonian age (Berdan, written communication, May, 1970).


Figure 19. California Co. and Coastal Petroleum Co. No. 2, Franklin County, Florida
10520'-10530'.
Baked shale. The dark areas are calcareous, and appear to represent
foraminifera. The gray matrix is a mud-stone with minute angular quartz
particles. Ordinary light X17.






BULLETIN NO. 55


Figure 20. Humble Oil and Refining Company C. W. Tindel No. 1, Jackson County,
Florida, 8881'-8891' (top 5%).
Fine grained siltstone overlying basalt and showing flowage and other
metamorphic effects. Ordinary light, X13.











4. -. *


444 :t- 4-
44 iZ'
Vr~


ri 1..4 444 4
*' 4 44-/

,r
r',1 .-'w .;




444 t44 4 4 j .

** 4 .r i 4


4; 4 444 44
74 r 4


y^ *54-


4.(
*l *"it'y'A a i


. 't ^ St'',"<


r,^ 1;~ 7.^ *^
W "% ''. t'
44 444' ',


'1 "




'44
44 7444
.r~


44*'>
4 4444



44


444 4,, .
4444


4,*


2' ,.
' r; ^ t


444 4 .a "
N-,



44 4 5 4s; *; | '1


's4'S.444 J',n4 .
t: '*"'^ f^H f:
?'r t % 2
'. ~a




'9,


U* 4 4X,





4 t4 .4 '



..' :: .' .; :" ^
C







^.A "" ;' b ka


i *: :.. ,.
4 ls 44' Q
2'
i '
44Y^ 4 4;]^a ^n ^* 44: 4444' 44 a "


Amygdaloidal (quartz) Basalt
Figures 21 a, b. Humble Oil and Refining Company C. W. Tindel No. 1, Jackson County, Florida, 8881'-8891'.
Quartz amygdule (bottom) surrounded by highly calcitized zone in basalt. Another large calcitized area, with very
minor quartz, is seen upper left. The slightly darker smaller areas are calcitized pyroxenes. Ordinary light and
crossed nicols, X28.


*r*K **.-W .*- "pl~ *-. .2v- ff*f;, *

i444..4 4..: i




*-44. 4N 4 '* '- f .' "
r ': ^ -, a' :^



^ ::- ,,^i' t 'K:*


4" 4 -~ i:4 :


.~ ..
~~_ c.






BULLETIN NO. 55


WALTON COUNTY
PAN AMERICAN PETROLEUM CO.
J. R. SEALY NO. 1 T. D. 11948 FT.
Sec. 9 T1S R18W Center SEk SE }.
Completed 1950. Well locality No. 9.
Top ofvolcanic rocks 11910 ft. Fragments (cuttings) 11935'-11940' heav-
ily altered porphyritic rhyolite.
Data from P. L. Applin (written communication 1967). Specimens were
examined as follows:
11920'-11930' Sandstone, arkose and felsite
11930'-11935' Sandstone, arkose and felsite
11935'-11940' Rhyolite porphyry ash with obscure shard structures in
trix of plagioclase, phenocrysts. Also much sandstone,
etc. Figures 22, 23.


Figure 22. Pan American Petroleum Sealey No. 1, 11935'-40'; Walton County, Flor-
ida.
Sericitized rhyolite porphyry or ash, with feldspar phenocrysts. Ordinary
light X35.








BUREAU OF GEOLOGY


Figure 23. Pan American Petroleum Sealey No. 1, 11935'-40', Walton County, Florida.
Sericitized rhyolite or ash. Ordinary light X35.

11940'-11945' Rhyolite porphyry ash with obscure shard structures in
matrix of plagioclase, phenocrysts. Also much sandstone,
etc.
11945'-11950' Rhyolite porphyry ash with obscure shard structures in
matrix of plagioclase, phenocrysts. Also much sandstone,
etc.


HUMBLE OIL AND REFINING COMPANY,
J. W. CAMPBELL NO. 1 FLAGLER CO., FLORIDA
Completed 1947 T. D. 4632' Well locality 10. Applin (1951) No. 19.
"Mixed tuff derived from an igneous complex. Origin, sedimentary or ex-
plosive igneous action." F. F. Grout. P. L. Applin (1951) Applin notes that
the igneous rock was encountered at 4588' and drilling continued in such to
4632' T. D.






BULLETIN NO. 55


The samples available have two recorded depths, one of them "corrected"
12' less than the other. The depths cited above are "corrected."
Cores for the interval 4560' to 4575' were studied as follows:
Core 67 4560'-70' recovery 83' feet top, middle and bottom, all
friable white sandstone.
Core 68 4570'-75' top friable white sandstone; middle buff to red
friable sandstone; bottom hard indurated red sandstone.
The top of the igneous rock in this well is at 4588'. Possibly the change
noted in the last core 68 may be caused by the igneous rock found 13 feet
lower down; but this interval is not represented by any sample.
Cores beginning at 4601' in the igneous section were studied as follows:
Core 69 (top) 4613'-18' recovery 3 ft. corrected measurement 4601'-06'
(bottom) 4613'-18' recovery 3 ft. corrected measurement
4601'-06'
Both samples are rather fine grained volcanic rock, the first reddish, the
second darker. Whitish clayey material coats the surfaces and veins the core
pieces.
Core 70 (top) 4618'-4624' recovery 3' corrected measurement
4606'-12'
(middle)
(about 6" above bottom)
These three samples are similar to preceding.
(bottom 6" approximately) This is dark gray fine grained rock, showing
(in 1 inch fragments) no agglomerate structure or clay veining or coatings.
Core 71 4624'-4624%' recovery 6" corrected measurement 4612'-
4612%' This is a fine grained dark gray rock.
Core 72 4624V'-4626' corrected measurement 4612%'-4614' This
specimen is a fine grained gray rock, with white clayey patches. In thin sec-
tion shows a heterogeneous agglomerate of heavily altered basaltic debris
and quartzite particles, seamed with veinlets of calcite and, possibly, pum-
pellyite. Figure 24 illustrates this rock. Without the thin section, the rock
could be termed fine grained basalt, but this rock, and presumably the
others above it, are almost certainly altered volcanic ash.
Core 73 No recovery
Core 74 4627'-29' recovery 6" corrected measurement 4615'-
4617'
No thin section is available, but careful inspection under a binocular micro-
scope suggests that it is like the preceding.
Core 75 4627'-29' recovery 1' corrected measurement 4615'-17'
Similar dense dark gray fine grained.
Core 76 4630'-31' recovery 1' corrected measurement 4618'-19'
Similar
Core 77 4631'-32' recovery 1' corrected measurement 4619'-20'
Similar







40 BUREAU OF GEOLOGY







41... :V





/ t, .,




















Figure 24. Humble Oil and Refining Company, J. W. Campbell No. 1, Flagler
County, Florida. 4624 -4626.




This is a volcanic agglomerate, perhaps hydrothermally altered ash.
Calcite hornblende veinlets cut the rock. The two light colored areas at the
left edge are aggregates of acicular pale green hornblende; the clear
areas at the right are granular quartz. The dark areas are mostly aggre-
gates of extremely fine black opaque material; a few are magnetite-
ilmenite. Under high i, ,,,,.,. r..... yellow epidote (?) and brown sphene
in irregular grains are seen. Ordinary light, X22.

Core 78 4632'-33' recovery 1' corrected measurement 4620'-21'
Similar
Core 79 4633'-34' recovery 6" corrected measurement 4621'-22'
Similar
Core 80 4634'-35' recovery 10" corrected measurement 4622'-23'
Similar
Core 81 4635'-36' recovery 1' corrected measurement 4623'-24'
Similar
Figure 24.. Hubl OladRfngCopanJ .CmbllN.1 ge

This~~~~~~~~~~;~ isavlcncaglmrte ehashdrtemll lerdah
Calit horblnd venesctterok h wih clrdaesa h
let dg ae g regte o aciula pale gre horblne th la
areas- attergtaegaua urz h akaesaemsl gr
gats f xtemlyfie bac oaqe atril; fw remaneit
ilmenite Une ihi...,,,..yllweioe()adbonshn








Similarlai agoeatpras yrteral ltrdah






BULLETIN NO. 55


Core 82 4636'-37' recovery 1' corrected measurement 4624'-25'
Similar. Some of the preceding have white, greenish, or in this core,
reddish veinlets. Some veinlets are mostly calcite; this one is a zeolite.
Core 83 ,I.:; -38' recovery 8" corrected measurement 4625'-26'
Similar
Core 84 4638'-39' recove:7 1' corrected measurement 4626'-27'
Similar; fine grained dark gray, with greenish veinlets one or two
millimeters wide. In thin section, an aggregate of rhyolitic and other igne-
ous fragments, including altered feldspars and pale green hornblende. Some
of the rhyolite fragments have micro-pegmatitic structure. (Fig. 25)
Core 85 4639'-40' recovery 1' corrected measurement 4627'-28'
Similar




















S .-A


S,~ ,-.. -o ... .








Figure 25. Humble Oil and Refining Company, J. W. Campbell No. 1, Flagler
County, Florida. 4638'-4639'.
Volcanic agglomerate-ash. The clear areas are quartz; the finely dotted
area, lower left, devitrified glass. Coarse feldspar grains, and greenish
pyroxene (?), both heavily altered, can be seen. Ordinary light, X22.








42 BUREAU OF GEOLOGY

Core 86 4640'-41' recovery 1' corrected measurement 4628'-29'
Similar
Core 87 4641'-42' recovery 1' corrected measurement 4629'-30'
Similar
Core 88 4642'-43' recovery 9" corrected measurement 4630'-31'
Similar, with fine salmon colored zeolite in veinlets.
Core 89 4643'-44' recovery corrected measurement 4631'-32' T.D.
Similar. In thin section an agglomerate of shattered quartz grains,
basaltic fragments, altered feldspars and mafic minerals, and black opaque
dust and iron oxide. (Figs. 26a, b)
Bass (1969) gives petrographic date for a sample designated as
"4641-4642 ft. A sample of Core 87, from this depth, 1 ft. recovery is
fine grained dark gray tuff."











































Figures 26a. b.


Humble Oil and Refining Company, J. W. Campbell No. 1, Flagler County, Florida. 4643'-4644'.
Volcanic agglomerate ash. The clear areas are mostly quartz, others are feldspathic. Large Carlsbad twinned
feldspars are seen in thin section, as large or even larger than the quartz aggregates, suggesting that the latter too
are of volcanic origin (phenocrysts) and not fragments of engulfed sedimentary quartzite or sandstone. Ordinary
light and crossed nicols, X22.







BUREAU OF GEOLOGY


PUTNAM COUNTY
SUN OIL COMPANY
H. E. WESTBURY ET AL. 3892' T.D.
Completed 1949. Well locality 11 Applin (1951) No. 25
"Volcanic ash and tuff." Applin (1951).
Bass (1969) has described core specimens from this well, as noted
below.
This well drilled into 19 feet of volcanic ash. Samples are available
from 3872' to 3892' T. D.
Core 190 3872'-74' recovery 7" mid 3 inches (specimen).
Hard reddish clayey rock with rounded quartz grains. The clay swells
and disintegrates in water, suggesting bentonitic volcanic ash.
bottom 3 inches: rather friable white clayey rock, no quartz grains.
Bass (1969) describes the material from 3871.5 to 3874 ft. as perhaps
a silty mudstone or a thoroughly weathered tuff; from 3876 to 3878 ft.
as microcrystalline welded tuff or pumice.
Core 193 3878'-3879' recovery 12" hard very fine grained reddish
rock.
Bass (1969) describes this rock as laminated tuff.
Core 194 3879'-3881' recovery 20" like the preceding with ellip-
soidal bleached areas a centimeter or two across. In thin section, it is
seen to be volcanic ash (Figure 27). It contains a marine (?) fossil.
This sample has been analysed (Table 3).
Core 195 3881'-3883' recovery 24"
top 1 inch: similar to preceding.





BULLETIN NO. 55


27. Sun Oil Company, H.S E. Westbury et al. 1. Putnam County, Florida.
'I .,





3879'-3881'.
Ash with fossil, upper right. The other structures seem to be intensely
altered fine-grained volcanic fragments. The dark areas are iron-stained.
Ordinary light X2232.


Figure







46 BUREAU OF GEOLOGY

Bass (1969) describes this core as lithic-crystal tuff with relict shard
structure.
bottom 1 inch: similar to preceding, grading from reddish to white.
Core 196 3883'-3885' recovery 12" Similar to preceding. In thin
section the reddish areas in the specimen are seen to be colored by red-
dish hematitic (?) dust, whereas the white areas are pale green, and
chloritic. A few highly altered fragments of coarser volcanic rock are
imbedded in an extremely fine grained clayey/matrix.
Core 197 3885'-3887' recovery 17" This is more grayish in color,
but otherwise like the preceding. In thin section it shows shard structures.
Bass (1951) gives further details. (Fig. 28)




















Figure 28. Sun Oil Company, H. E. Westbury et a.No. Putnam County Florida.


















Fine-grained rock, with scattered sodic plagioclase feldspar crystals
(white). The white streaks are minute fissures filled with quartz. Ordinary
,light X ,.



I -


S-, '. : .




.3885' 3887'.





Fine grained rock, with scattered sodic plagioclase feldspar crystals
(white). The white streaks are minte fissures filled with qartz. diary




light X17'2.
light X17:2.






BULLETIN NO. 55


Core 198 3887'-3889' recovery 12" This is bluish gray ash, with
numerous reddish grains a millimeter or two across. They are usually feld-
spar, either single large crystals, or granular aggregates, or highly feld-
spathic rhyolite. Some fragments consist of aggregates of almost color-
less spherulitic chlorite.
Bass (1969) describes this core: Clastic vaguely laminated welded tuff.
Core 199 3889'-3890' recovery 10" Similar to preceding with fairly
large (several millimeters or more) fragments of well crystallized rhyolite
and single unaltered plagioclase feldspars; also quartz grains.
Bass (1969) describes this core as plastic volcanic conglomerate or ag-
glomerate. (Fig. 29)


Figure 29. Sun Oil Company, H. E. Westbury et al. No. 1, Putnam County, Florida.
3887'-3891'.
Shows heterogeneous character. The large fragment (lower left) sug-
gests either a shattered quartz crystal or a fine-grained sandstone. Ordinary
light X17;2.






48 BUREAU OF GEOLOGY

Core 200 3890'-3892' T.D. recovery 24" Similar to preceding. (Fig.
30)
Bass (1969) describes this as similar to his preceding sample, with
laminated welded tuff.












4AT;V4






























Figure .30. Sun Oil Company, H. E. Westbury et al. No. 1, Putnam County, Florida.
3890'-3892' T.D.
Shows variegated structure (fine and coarse). The coarse is largely quartz.
Ordinary light X17I.
Fiue:0 unOlCmayH .Wsbrye l o 1 unr outFoia
3890'-392'T.D
Shw areae srcue fn adcase.Tecoreislrey urz
Ordnay lgh X132







BULLETIN NO. 55


MARION COUNTY, FLORIDA
SUN OIL COMPANY
HENRY N. CAMP NO. 1 T.D. 4637'
Completed 1947 Well locality 12 Applin (1951) No. 23
"Vocanic agglomerate or tuff of rhyolitic composition. 'Mixed tuff de-
rived from an igneous complex.' F. O. Grout." Applin (1951)
Applin gives 22 feet of volcanic rock beginning at 4615 ft.
Bass (1969) describes specimens from this well, as noted below. He
describes cuttings from 4500 to 4610 ft. and core from 4574 to 4584 ft.
as coarse grained conglomeratic sandstone loosely cemented by chlorite;
about 1 percent or less of the sandstone is rhyolitic ash.
Only two samples are available:
Core 22 4574'-4584' (two different rock types)
a) fine grained ash?
b) coarse grained agglomerate or arkose fragments a milimeter or two
in size. (Figure 31)
There is such a difference between these two specimens that it is pos-
sible that the coarse grained rock (b) is mislabeled. It shows definite indi-
cations of metamorphism by igneous contact, and contains fragments of
rhyolitic rock (fig. 28) with coarse quartz and feldspar. The matrix has
been recrystallized to micaceous aggregates.
Core 23 (bottom) 4623' Again there are two somewhat contrasting
specimens, one a coarse volcanic agglomerate, the other rhyolitic welded
tuff or rhyolite, with large quartzes and sodic feldspars. Both however,
could well represent variant phases of a single ash fall, shifting winds and
variations in explosive activity in the crater causing marked changes in
material deposited at any one point.
Ross (1958) cited by Bass (1969) found 4618 to 4653 ft. to be welded
tuff. Bass also found cuttings from 4610 to 4630 ft. to be rhyolitic welded
tuff.
Dorothy Carroll (1963, p. All, Fig. 6) found her heavy mineral assem-
blage A in quartzite at the Camp well at a depth of 4376-4383 feet below
sea level (core 121). This assemblage also occurs in quartzite in Humble
Oil and Refining Co. C. E. Robinson No. 1 (Levy County) which is con-
sidered to be Early Ordovician in age on the basis of fossils. The quart-
zite in core 121 from the camp well is also probably Early Ordovician (Ber-
dan, 1970, written communication).
Three other wells have been drilled in Marion County in none of which
igneous rock was reported. They are:
J.S. Cosden, W. L. Lawson No. 1 4334' T.D.
Ocala Oil Corp., Clark-Ray-Johnson No. 1 (York) 6180' T.D.
Sun Oil Co., H. T. Parker No. 1 3845' T.D.
All are reported to have bottomed in quartzitic sandstone (P. L. Applin,










I S
aV






l o'

'-7' k-hII


*1


4.
N.


Figure 31. Sun Oil Company, Henry N. Camp No. 1, 4574'-4584', Marion County, Florida.
Coarse agglomerate or arkose. Shows large quartz grains with micro-brecciated structure. The dark grain lower right
is rhyolite, with typical rounded quartz phenocryst. Ordinary light X14.







BULLETIN NO. 55


1951), of probable Early Ordovician age (Berdan, 1970, written com-
munication).
The Sun Henry N. Camp N. 1 with volcanics at 4623' is only about
20 miles east of Ocala Oil Corp. Clark-Ray-Johnson No. 1 (York), which
reportedly found no igneous rock down to 6180' T.D.


LEVY COUNTY, FLORIDA
HUMBLE OIL AND REFINING CO.
C. E. ROBINSON NO. 1 T.D. 4609'
Completed 1949 Well locality 13 Applin (1951) No. 60
"4317'-4344' decomposed igneous rock; underlies lower Cretaceous
sandstone. 4344'-4377' basalt; overlies altered black shale of Paleozoic age."
(Applin 1951)
Three very small samples are available. There is some question as to
exactly which cores they represent. The depths, however, are believed to
be correct.
Core 59 (?) 4331'-4336' This is a rather coarse granular aggregate,
mostly greenish, but also brownish grains. In thin section, the rock is seen
to consist of a chlorite-clay(?) matrix with abundant carbonate (dolomite?)
areas, both with rather obscure radial crystallization. Coarse opaque
grains, some ilmenite, other leucoxene and limonite, are numerous. Quartz
is almost absent. (Figure 32).











i:r

IA""e


y i,,
-i *2 ,''
fl^ ,ps


-* t


t4~t


Calcitized basalt
Figure 32. Humble Oil and Refining Company, C. E. Robinson No. 1, Levy County, Florida, 4331'-4336'.
Radially crystallized masses of dolomite (?) in a chloritized matrix. Feldspars are replaced by obscurely radial clay (?)
material, mafic minerals by pale green chlorite. Ordinary light, X2232.


_ _


6.'49









BULLETIN NO. 55


Core 59 (or 60?) 4344'-4356' near top "overlain by 8 ft. of red clay"
- Applin. This is a fairly hard light gray rock. In thin section, it is seen
to be a diabasic rock, with fresh plagioclase and calcitized augite. It shows
to a relatively minor degree the same type ofhydrothermal alteration seen
in the preceding specimens (Fig. 33). Pyrite unaltered to limonite, and
ilmenite unaltered to leucoxene, are present. The "red clay" of Applin
may represent an intensely altered part of the igneous body.
Core 59(?) 4358'-4359' This is augite diabase, showing none of
the alteration of the preceding samples (Fig. 34).


I~ I


;Ii

'to


"


K, 'C:


'I I.

7 '. ; / '. 5
."I



a'"
-" -i^

I~ '. ^: .r


*~~~~ : f^^''


7-f'I .- ,A' tt I'^
% '. '; ''w ,, 14 .^ ^ '
A -- i -

I .-*" '


-" .' ,.* ^ t 1 ^ -
,r g i ri. :7 A! P -'

'I --


-L"'


A


I"
-? r
-; 72'
/1.
'.4: )
1'r:~ '4'~~~ .*
4., '4'f dr
.Lr7 ct


Calcitized basalt or diabase
Figure 33. Humble Oil and Refining Company, C. E. Robinson No. 1, Levy County,
Florida, 4344'-4356' (near top).
Although the plagioclase is unaltered, nearly all the augite is replaced
by calcite. The black areas are mostly fresh magnetite-ilmenite with a
little pyrite. Minor quartz is present and green chlorite. Ordinary light,
X22.5.


t






































Almost unaltered diabase
Figure 34. 'Humble Oil and Refining Company, C. E. Robinson No. 1, Levy County, Florida, 4358'-4359'. Ordinary light, X22.5


I


~








BULLETIN NO. 55


Although the 28 feet of igneous section appears to show a progressive
degree of alteration from top to bottom, this may not be the result of
weathering, but ofhydrothermal alteration.
"The diabase in the Robinson well overlies 232 feet of quartizitic sand-
stone with minor amounts of shale, which is dated as Early Orodivician
on the basis of linguloid brachiopods" (Berdan and Bridge, 1951, p. 70).


VOLUSIA COUNTY
GRACE DRILLING CO.,
RETAIL LUMBER CO. NO. 1 T.D. 5424'
Completed 1949 Well locality 14 Applin (1951) No. 26
"Rhyolitic (?) volcanic rock" Applin (1951).
Applin (1951) reports that this well drilled 21 feet in volcanic rock. A
specimen of cuttings from 5-124'. T.D. show arhyolitic rock almost
wholly plagioclase feldspar (near oligoclase-andesine) with a little quartz
and little or no mafic minerals. It is illustrated in Figure 35.
This well is less than 20 miles NNW of the Sun Co. Powell Land Co.
No. 1, which at a depth (! ','-i-22 drilled rock reported as over 400 m.y. age.










BUREAU OF GEOLOGY


'.


44.


=-4


-- "


.% *. 4

.' .4

.rr ^
* "" ; I 2.


r~F Mla
6~


I,


,1


r ,A


~2<


'it
.4 ~ -. 1
5. ) P' -


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4., 4i


* .1
.1


*11
- 4 h '


.4, Is -'
'<-~ V- ,5'li


S ..

k *' *:, ."
ri ,


*~~~~~1 4 _,tA .-. .


^4' ..- ; A
.7"`~


Rhyolite

Figure 35. Grace Drilling Co., Retail Lumber Co. No. 1, Volusia County, Florida.
542432 T.D.
The volcanic rock consists almost entirely of moderately sodic plagioclase
in interlocking aggregates of lath shaped crystals, some porphyritic and
euhedral, and very minor interstitial quartz. The feldspar is slightly
sericitized, with reddish dust giving it a brownish tint in section. Some
black ore grains, and a little calcite, are present. The large rectangular
crystal is plagioclase feldspar. Ordinary light, X27.


4t'
V.


S-* I It


44




4)

4f


,' .1


a



1W


0"
*


/* -
-. If








BULLETIN NO. 55


VOLUSIA COUNTY
SUN OIL CO.
POWELL LAND CO. NO. 1 5958 ft. T.D.
Completed 1946 Well locality 15 Applin (1951) No. 7
Hornblende diorite (Applin 1951)
This is one of the three wells in east central Florida that Applin (1951)
considered to have reached the "metamorphic basement," the others being
Lake County, J. Ray Arnold No. 1 and Osceola County, N. Ray Carroll
No. 1. Later the St. Lucie County, Amerada Cowles Magazine No. 2
and Hillsborough County, Humble T. S. Jamison No. 1 drilled into similar
"metamorphic" rock.
Bass (1969) has studied specimens from this well in great detail as
noted below.
Nineteen specimens from this well, representing depths from 5903' to
5958' T.D. have been studied. "According to D. J. Munroe (Sun Co.
Geologist*) this well encountered a weathered zone? beginning at 5910'
S. .memo to Watson Monroe from Applin, April 3, 1947. The follow-
ing are notes on the samples studied:
Side Wall Core 5903' White Sandstone
Side Wall Core 5906' White sandstone
Cuttings 5910'-20' White sandstone, etc.
Cuttings 5920'-30' White sandstone, etc.
Core 178 5922'-25' 3' recovery, top ofcore. Soft coarse volcanic
rock, now clay, but with original texture.
(Figure 36)
Core 178 5922'-25' has been interpreted as possibly a weathered zone,
and indeed there is a striking contrast between the white sandstone and
the underlying volcanics, with no indication that the sandstone has been
metamorphosed by the volcanics. In other words, the sandstone deposi-
tion is subsequent to the consolidation of the igneous rock. In thin section,
the rock is seen in Figure 36. Rather than weathering, intense hydrother-
mal alteration is possible. The rock is illustrated in Figure 36. Minute ang-
ular fragments of fairly fresh alkalic feldspar are seen sparingly, surrounded
by clay. Vivid green, strongly pleochroic (yellowish to bright green) platy-
fibrous chlorite-like mineral may be ferrostilpnomelane. Small apatite crys-
tals are present.
Bass (1969) classes the rock from >'-22-25 ft. as "either transported
material or weathered basement rock that was mixed with overlying ma-
terial during mass movement."
Cuttings 5930'-40' White sandstone, volcanic debris
Cuttings 5940'-50' Volcanic debris, white sandstone, etc.
Cuttings 5950' Volcanic debris, white sandstone, etc.


"Deceased.







































"Weathered" igneous rock
Figure 36. Sun Oil Co., Powell Land Co. No. 1, 5922'-5925', Volusia County, Florida.
The light colored areas are cryptocrystalline clayey material; the dark, chloritic aggregates; and the black, limonitic
material. Shattered quartz grains (white) suggest explosive hydrothermal activity. The limonitic material may have re-
placed ferromagnesian silicates; a few black ore grains are unaltered. Ordinary light, X15.5.







BULLETIN NO. 55


MARION COUNTY, FLORIDA
SUN OIL COMPANY
HENRY N. CAMP NO. 1 T.D. 4637'
Completed 1947 Well locality 12 Applin (1951) No. 23
"Vocanic agglomerate or tuff of rhyolitic composition. 'Mixed tuff de-
rived from an igneous complex.' F. O. Grout." Applin (1951)
Applin gives 22 feet of volcanic rock beginning at 4615 ft.
Bass (1969) describes specimens from this well, as noted below. He
describes cuttings from 4500 to 4610 ft. and core from 4574 to 1i~4 ft.
as coarse grained conglomeratic sandstone loosely cemented by chlorite;
about 1 percent or less of the sandstone is rhyolitic ash.
Only two samples are available:
Core 22 4574'-4584' (two different rock types)
a) fine grained ash?
b) coarse grained agglomerate or arkose fragments a milimeter or two
in size. (Figure 31)
There is such a difference between these two specimens that it is pos-
sible that the coarse grained rock (b) is mislabeled. It shows definite indi-
cations of metamorphism by igneous contact, and contains fragments of
rhyolitic rock (fig. 28) with coarse quartz and feldspar. The matrix has
been recrystallized to micaceous aggregates.
Core 23 (bottom) 4623' Again there are two somewhat contrasting
specimens, one a coarse volcanic agglomerate, the other rhyolitic welded
tuff or rhyolite, with large quartzes and sodic feldspars. Both however,
could well represent variant phases of a single ash fall, shifting winds and
variations in explosive activity in the crater causing marked changes in
material deposited at any one point.
Ross (1958) cited by Bass (1969) found 4618 to 4653 ft. to be welded
tuff. Bass also found cuttings from 4610 to 4630 ft. to be rhyolitic welded
tuff.
Dorothy Carroll (1963, p. All, Fig. 6) found her heavy mineral assem-
blage A in quartzite at the Camp well at a depth of 4376-4383 feet below
sea level (core 121). This assemblage also occurs in quartzite in Humble
Oil and Refining Co. C. E. Robinson No. 1 (Levy County) which is con-
sidered to be Early Ordovician in age on the basis of fossils. The quart-
zite in core 121 from the camp well is also probably Early Ordovician (Ber-
dan, 1970, written communication).
Three other wells have been drilled in Marion County in none of which
igneous rock was reported. They are:
J.S. Cosden, W. L. Lawson No. 1 4334' T.D.
Ocala Oil Corp., Clark-Ray-Johnson No. 1 (York) 6180' T.D.
Sun Oil Co., H. T. Parker No. 1 3845' T.D.
All are reported to have bottomed in quartzitic sandstone (P. L. Applin,









BUREAU OF GEOLOGY


-~ ~ A.:'\ '"1'


C


*; a k' **

,t F *



? r -j, ..~ ;
.'* t **'. ". ', *< 5
A4 '








~i
tr A .'





.f/| tA^ A( : tA



..~~ *A'," ^'^
t.I
-. : '., ,.. c '^ > -
"i c .'. .- I (

*^- .r' -'"^,": ^^* "R. *



< .;a 3 -^ 1t ". *'


q


1
"s;

I"
t,~:


r.-n*-,--


Figure 37. Sun Oil Co., Powell Land Co. No. 1, 5954'-5955', Volusia County, Florida.
The small smooth rectangular area bottom center is green chlorite;
another area is at the center. The clear areas are quartz, the darker
hornblende; the gray mostly feldspar. Ordinary light, X27.


WA
A'
~ 34
-4


'A

(>111


'' ?jr sl


B~tl


; a








BULLETIN NO. 55


Diorite with epidote
Figure 38. Sun Oil Co., Powell Land Co., No. 1, 5954'-5955', Volusia County, Florida.
Shows epidote veinlet (lower left). Ordinary light, X20.5.







6r'- F*


0.5 m h









0.5 g" .

Hornfels
Figures 39a, b. Sun Oil Co., Powell Land Co. No. 1, 5955'-5956', Volusia County, Florida.
Shows brown biotite and pale green hornblende with quartz-sodic plagioclase. Concentrations of either or both
together, the ferromagnesian minerals are seen; here the quartz-feldspar is finer grained (lower left). All grains
are anhedral, and the texture is granitic. Ordinary light and crossed nicols, X27.


e'T










i _e^ ?yi *. ItC, *1





.. .., ,.-- ,, ; :
t .%'r-r *' "
-. -





r- : "V R r't
a -r



-. a..- ..... .





W b1 t" -'" .*
1.-










Figure 40. Sun Oil Co., Powell Land Co 1, 5957,'-5958', Volusia County, Florida.
Rock similar to preceding figures, showing ma concentration. Orindary light, X16.
Fig e; o.U 1, 5 8 lu N id.







BUREAU OF GEOLOGY


Rock from core 180 5953-5954 ft. has been dated by H. Thomas, R.
Marvin, P. Elmore, and H. Smith of the U. S. Geological Survey (Meuhl-
burger, W. R., et al., 1966) as |sii- m.y. (by K-Ar).
Bass (1969) found for the rock from 5951 to 5958 ft.
5951'-5955' Hornblende in diorite 459 m.y. (K-Ar)
5951'-5955' Plagioclase in diorite 342 m.y. (K-Ar)
5955.5'-5958' Biotite in hornfels 524 m.y. (K-Ar)
5955.5'-5958' Hprnblende in hornfels 393 m.y. (K-Ar)
5955.5'-5958' Biotite in hornfels 634 m.y. (Rb-Sr)
Bass offers various explanations of these discrepancies.
To summarize these data, it appears that these dates aggree in indicating
an age for the rock in excess of 342 m.y., that is, an age older than Miss-
issippian.


LAKE COUNTY, FLORIDA
LAKE COUNTY OIL DEVELOPMENT COMPANY OF FLORIDA
SOUTH LAKE NO. 2, (J. R. Arnold No. 1) T.D. 6129'
Completed 1937 Well locality 16 Applin (1951) No. 5
"Granite at 6103" Applin (1951)
In a letter to Watson Monroe, Applin (Nov. 4, 1937) wrote ".... in
1937 a sample was submitted to W. H. Tomlinson at Swarthmore, Pa.,
who reported it to be alaskite, 'a granitoid rock having 50 percent ortho-
clase, 40 percent quartz, 10 percent oligoclase, and 2 percent biotite.'
Tomlinson's opinion expressed at that time was to the effect that the alas-
kite was probably a dike ... ." Later, a few tiny fragments of this rock
were inspected by Charles Milton who agreed with Tomlinson's findings
as to lithology.
A thin section obtained from Mr. A. P. Bennison, of the Sinclair Oil and
Refining Company labeled "Oil Dev. Co. of Fla. South Lake Well Core
6107'-'1 Granite 17-24S-25E" made by Tomlinson, is definitely the same
rock. It shows no trace of weathering (Figures 41a, b).
It may be noted that this type of rock is quite similar to "granitic" rock
encountered by drilling in Perce County, Georgia.
This is one of the most controversial of the Florida wells. Schuchert
(1943) mentions a miliolid limestone, referred to middle Cretaceous at
5383'; anhydrite between 5383' and 6050'; followed by red clays, gravels,
sands and then granite. The owner of the well denied the presence of
granite. Campbell (1939) observes that "granite or not, the miliolid lime-
stones at 5383', some beds of anhydrite, and the red sands and gravels

"The original report to Charles Milton, dated Nov. 1, 1962, noted that "this age may
be low by 20 percent or more due to the variable argon retentivity of the potassium-bear-
ing minerals of this sample."











*T
Sf_


0.5 mr
w_


Figures 41a, b.


Oil Development Company of Florida South Lake No. 1,6107'-28'
The clear areas are quartz, the grey mostly microcline and oligoclase. A very little brown biotite and black mag-
netite is present. Very similar rock is known to be arkose more or less metamorphosed by nearby doleritic intrusives.







BUREAU OF GEOLOGY


are regarded in this paper as representing middle Cretaceous rocks, and
the well is assumed to be in Jurassic at the bottom of the hole. In this con-
nection it might be mentioned that Schuchert regards granites in Central
Cuba as having been intruded at the end of the Jurassic. Dickerson also
notes the association of granite with his Oxfordian."


ORANGE COUNTY
WARREN PETROLEUM CORP. GEORGE TERRY NO. 1
Sec. 21 T23S R31E Center SWi SEi T.D. 6589'
Completed 1955 Well locality 17.
Top of granite at 6550'. Only cuttings. No samples available.
Data from Applin (personal communication, 1967).


INDIAN RIVER COUNTY
AMERADA PETROLEUM CORP.
FONDREN MITCHELL NO. 1 T.D. 9488'

Section 28, T31S R35E 1980' S and 1980' E of NWM Sec. 28
Completed 1956 Well locality 18.
Top of weathered (?) igneous rocks at 9410'. Rock reported as "ande-
site". Applin (personal communication, 1967).
Samples (cuttings) available as follows:
9424-29 9454-64
9429-34 9464-69
2434-39 '9469-74 Figures 44, 45
9439-44 9474-79
*9444-49 Figures 42, 43 9479-84
9449-54 *9484-89 T.D. Figure 46 All in volcanic rock.
* Thin sections as follows.
9444-49 Brown basalt, consists of fresh calcic plagioclase laths with
colorless to greenish or reddish monoclinic pyrogene, and black ilmenite.
Green to brown chlorite with ilmenite forms small segregations in the
rock.
9469-74 Amygdaloidal calcitic basalt; basalt with much calcite veins
and chlorite amygdules.
Figures 44 and 45 (?)
9484-89 Amygdular basalt. Much calcite, chlorite and quartz in
amygdules.
Figure 46
The rock could be termed a moderately altered amygdaloidal basalt.
It appears to be very similar to the amygdaloidal basalt from Appling
County, Georgia, described and illustrated by Milton and Hurst (1965);









BULLETIN NO. 55


Basalt
Figure 42. Amerada Fondren Mitchell No. 1, Indian River County, 9444'-9449',
Ordinary light x 35.









BUREAU OF GEOLOGY


3a .~a 1, tr N

I _st*$v1&4




t "-~" L ~ A


'' ""zagi
i ~
f
r.
,. ,1 ;~5

.cF
"F"jb t ~~-;


Diabase with interstitial chlorite-ilmenite.
Figure 43. Amerada Fondren Mitchell No. 1, Indian River County, 9444'-9449'.
Shows plagioclase laths and augite with ilmenite, and green chlorite
with black ilmenite aggregates. The chlorite varies in color from green to
brown. Ordinary light x 150.








BULLETIN NO. 55


Figure 44. Amerada Fondren Mitchell No. 1, Indian River County, Florida 9469'-
9474'.
Calcite-chlorite-quartz segregations in basalt. The large mass (left of
center) is calcite, bordered with (clear) quartz. Ordinary light x35.







BUREAU OF GEOLOGY


0 1ni


Figure 45. Amerada Fondren Mitchell No. 1, Indian River County, Florida, 9469'-
9474'.
Detail of Figure.
Amygdaloidal basalt. Shows amygdaloid in center of picture with green
chlorite (gray areas), plagioclase laths, quartz, and ilmenite; the large
grey areas at top, left and right are calcite, and the clear areas bordering
the calcite are quartz. Ordinary light x 150.








BULLETIN NO. 55


'1t2r AI "~~i.


Figure 46. Amerada Fondren Mitchell No. 1, Indian River County, Florida, 9484'-
9489' T.D.
Basalt, with considerable quartz (most of the light-colored areas in the
picture). Green chlorite, calcite, and ilmenite are also abundant. The
plagioclase feldspar is fairly fresh, but the augite is mostly altered to ob-
scurely crystallized chloritic aggregates. Ordinary light, x12.


and indeed, to the amygdaloidal basalts of northern Florida dk. IIIl .- i
elsewhere in this report.
Figures 47a and 47b show the appearance of the rock in thin section. A
chemical analysis is given in Table 3.
Dating by Grasty (Table 2) gave a K-Ar age of 89.3 + 2 m.y. (middle
Cretaceous).
12744' In hand specimen resembles the preceding. In thin section how-
ever it is markedly different. The texture is fine grained granitic, and the
rock consists essentially of quartz and moderately sodic plagioclase, near








































'C1


0.5 mm
I 1


Figures 47a, b.


.5 mm
_ _j


Amygdaloidal basalt
Amerada Petroleum Co., Cowle Magazine No. 2, St. Lucie County, Florida, 12734'.
47a (ordinary light). Shows proportion of black ore grains and feldspar, and shape and size of amygdules which
contain pale green chlorite apparently identical to the interstitial chlorite replacing augite, etc. which is completely
gone.
47b (crossed nicols). The twinned plagioclase feldspars are the most abundant mineral; the black areas are
mostly pale green chlorite and ilmenite. Ordinary light and crossed nicols, X16.






BULLETIN NO. 55


andesine in composition. It shows little alteration, usually no more than
a few minute chloritic flecks. There is very little of the green chlorite
abundant in 12734'; what there is, is mostly associated with opaque ore
grains, surrounding and filling cracks in these. One or two areas suggest
olivine now replaced by ore and chlorite. No hornblende, abundant in
the following 12748' rock, is present; but there is much brown biotite
mostly heavily altered to brown chlorite? serpentine? Often the biotite
and its alteration product contain a network of rutile needles, hexagon-
ally oriented. Apatite is a minor accessory. Many of the rather coarse
black ore grains are shattered and chlorite-serpentine fills the cracks.
Figures 48a and 48b show the microscopic aspect of this rock; and a
chemical analysis is given in Table 3.
Dating by Grasty (Table 2) of this rock by K-Ar gave 226 6 m.y. and
224 3 m.y. (late Permian or early Triassic). Bass, however (Table 2, ob-
tained two widely different K-Ar ages for samples from this core from
148 m.y. (middle Jurassic) to 399 m.y. (late Silurian or early Devonian),
and for a third, by strontium isotopes, 530 m.y. (middle Cambrian).
12748' This rock also resembles the two preceding superficially, but in
thin section differs markedly from both.
It has a rather coarsely granular texture, and consists essentially of un-
altered green hornblende, quite fresh calcic plagioclase, and quartz. The
coarse black ore grains (ilmenite?) are unfractured. A little brown bio-
tite is present, some fresh, but most heavily altered to vague brown chlor-
itic material. Very few and small areas of pale green chlorite similar to
that in 12734' and 12744' with irregular outlines are present. Typical
areas in thin section are shown in Figures 49a and 49b.
This rock has been K-Ar dated by Grasty (Table 2) 308 5 m.y. (upper
Mississippian or lower Pennsylvanian) and the hornblende from it by
Bass, also K-Ar (Table 2) 470-503 m.y. (upper Cambrian or lower Ordovi-
cian).
Obviously, these dates do not agree too well, and their precise signifi-
cance is uncertain.




, ,_ .W 1. :: .l^ _*'*' *" '. .
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4 1-.:




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^. "" 'As '
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-, ,if tr -' i '' "
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t- ~~E .. I L ;*
1:15 m A r rf. ?.- i~ *.
I_______ F x*,B *-.. .* *


Figures 48a, b.


Granite
Amerada Petroleum Co., Cowles Magazine No. 2, 12744', St. Lucie Co., Fla. Thin section, ordinary light and crossed
nicols, X6.
The light colored areas (ordinary light) are quartz and andesinic plagioclase; the gray areas are brown alteration
produces of hornblende, now mainly altered biotite, serpentine or chlorite. The small black areas (lower right) are
mostly black iron (titanium) oxide, probably ilmeni, with a little pyrite. They have been shattered and the cracks
filled with serpentinic-chloritic material.



































Diorite
II















Figures 49a, b. Amerada Petroleum Co., Cowles Magazine No. 2, 12748', St. Lucie Co., Fla. Thin section, ordinary light and crossed
nicols, X6.
Shows abundant unaltered green hornblende and calcic plagioclase, with minor quartz and black opaque ilmenite (?). c.a






BUREAU OF GEOLOGY


ST. LUCIE COUNTY
AMERADA PETROLEUM CO., COWLES MAGAZINE NO. 2
Completed 1957 Well locality 19 12749'T.D.
Three specimens of large size core were received from Paul L. Applin,
through E. J. Henderson, Geologist, Amerada Petroleum Co., August 20,
1957, from 12734', 12744', and 12748'. The three rocks, although they
cover a range of only 14 feet, show remarkable diversity. Whereas the up-
permost rock, 12734', can be readily identified as basaltic, the middle
specimen 12744' has a granitic aspect, and the bottom rock 12748' would
pass as common diorite. The two lower core samples have been studied in
considerable detail by Bass (1969) with age determinations; similar studies
of all three cores are given here.
12734' is a hard gray rock, mottled with white flecks of calcite a centi-
meter across, and showing black slickensided surfaces.
In thin section it shows a uniform aggregate of andesinic plagioclase
laths, with abundant small euhedral black iron oxide (ilmenite?) grains.
Almost as abundant as the plagioclase is green chlorite, interstitial to the
feldspar and evidently a replacement of pre-existing mafic minerals,
probably pyroxene. Similar chlorite showing low bluish interference
colors under crossed nicols, also forms spherical vesicles or blebs, a couple
of millimeters across. Around and contiguous to these, the black ore grains
are replaced by brown sphene. Irregular small patches of calcite are strewn
through the rock. The feldspars in this rock are fairly fresh, mostly appar-
ently unaltered. They are somewhat fissured, the fissures being filled with
greenish chlorite.

OSCEOLA COUNTY, FLORIDA
HUMBLE OIL AND REFINING CO.
W. P. HAYMAN NO. 1 T.D. 8798'
Completed 1946 Well locality 20 Applin (1951) No. 24
This is one of two wells in Osceola County (the other being the
Humble Oil and Refining Co., Ray Carroll No. 1). Samples are available
from 8619' to 8793%', with interruptions.
Rhyolite from 8781' has been K-Ar dated 173 4 m.y. (Lower Jurassic)
by Grasty (Table 2).
58 feet of rhyolite, to 8798' (T.D.) were drilled.
Core No. Depth
253 8619'-8629' Friable gray sandstone
254 8655'-8658' Gray slickensided shale with coarse quartz
grains. In thin section, seen to be largely
volcanic debris, probably ash. The quartz
grains show no rounding, and many show
secondary enlargement.







BULLETIN NO. 55


255 8734'-8744'
recovery 5 ft.


256 8744'-8750'
257 8750'-8756'


8753'-8756'
8756'-8759'
8759'-8765'
8765'-8770'


8770'-8772'
8772'-8775'
8775'-8778'
8778'-8780'
8781'-87811%'


273 87812'-8783'
275 8786'-8787'


276 8789'-8790'


"Top 4 ft. of core is gray and black con-
glomerate sand. Bottom 1 ft. of core is por-
phyry with sand intrusions." (Drillers' log).
Sample consists of small hard gray igneous
rock fragments with sandy debris.

Top 1 ft. gritty clayey rhyolitic arkose.
Consists largely of sub-angular fragments
of quartz, micro-pegmatite, and sodic feld-
spar, with interstitial clayey matrix. An-
other sample of the same piece of core in-
cluded both sandstone and volcanic rock
fragments. Next to the top 1P ft. rather
firm carbonaceous (coal?) material. Bottom
six inches rhyolite fragments.

Slate-gray stony tuff (?) with small aphani-
tic inclusions and white kaolinized feld-
spars.
Microscopic: quartz and oligoclase-ande-
sine phenocrysts in feldspathic ground-
mass. Quartz euhedral (rhombohedra and
prisms), also spheroidally rounded. Plag-
ioclase in part calcitized; no albite twin-
ning, only Carlsbad. No mafics, very
scanty chlorite and apatite. (Fig. 50, Rhyo-
lite)


Very much like core 257 8750'-8753' -
very small hornblende and biotite, calcite
patches. (Figs. 51a and 51b)




"Rhyolite 173 4 m.y." Lower Jurassic
(Table 2)

Dark gray stony rock with red feldspar
phenocrysts. Quartz and albitic-oligoclase
phenocrysts in microcrystalline matrix. No
mafics. (Figs. 52a and 52b)
Same






BUREAU OF GEOLOGY


277 8790'-87903i'
279 8792%'-8793%'
280 8795%'-8796'1


Same


Rhyolite
Figure 50. Humble Oil and Refining Company, W. P. Hayman No. 1, Osceola
County, Florida, Core 257, 8750'-8753'
Rounded and sub-rounded quartz phenocrysts in fine grained felsic
groundmass. Near the center is a small sodic plagioclase phenocryst.
Ordinary light X17%.





































0 5 mm 0.5 mm


Porphyritic rhyolite
Figures 51a, b. Humble Oil and Refining Co., W. P. Hayman No. 1, Osceola County, Florida, Core 262, 8765'-8770 ft.
Shows rounded quartz phenocrysts and large sodic plagioclase in fine-grained felsic groundmass. Ordinary
light and crossed nicols X17,.







00

i,


























Rhyolite
Figures 52a, b. Humble Oil and Refining Co., W. P. Hayman No. 1, Osceola County, Florida, Core 275, 8786-8787 ft.
Rounded quartz and sodic plagioclase phenocrysts in a fine-grained felsic groundmass, which is coarser in
irregular streaks. Ordinary light and crossed nicols X17l.






BULLETIN NO. 55


OSCEOLA COUNTY
HUMBLE OIL AND REFINING CO. J. RAY CARROLL NO. 1
80441' T.D. Well locality 21 Applin (1951) No. 6
Applin ( 1951) lists the 14 feet of bottom rock in this well as "altered
and veined biotite granite" as determined by F. F. Grout. He also gives
T.D. as 8049 ft.
This is one of the three "metamorphic basement" wells in central eastern
Florida (the other two Volusia County Powell Land Co. No. 1 and Lake
County Oil Development Co. South Lake No. 2 J. R. Arnold No. 1)
which led Applin (1951, Fig. 1) to indicate a triangular area of several
thousand square miles, including all or part of Volusia, Seminole, Lake,
Orange, Osceola, Polk, and Brevard Counties as underlain by "pre-Cam-
brian granite, diorite, and metamorphic rocks."
Bass (1969) describes rock from this well as quartz monzonite.
Material studied from this well is:
Core 174 7904'-7914'
Core 175 7965'-7975'
Core 176 7975'-7984'
All of these are sand and friable sandstone.
Core 177 8034'-8042' The top of the igneous rock is in this core
(P. L. Applin).
Core 178 8042'-80421' T.D.
Both of the last two cores are of similar rock, granitic in appearance,
with much coarse pink feldspar and green chloritic areas. Microscopically
it resembles a hydrothermally altered aplite, containing abundant quartz
and kaolinized-sericitized albite-oligoclase with veins and replacements
of calcite; potash feldspar, with small optic angle (sanidine?) is sparingly
present. Green chlorite, strongly pleochroic, apparently originally biotite
is the only mafic mineral. Minor accessories are magnetite ilmenite,
leucoxene, apatite, and an occasional zircon.
Three thin sections show little variation.
This rock has been dated by Bass (1969) by Sr87/Sr86 as 530 m.y. The rock
is shown in Figures 53a and 53b.






06
Asn


5? P


-U




a 0
,i: 0
0


*'-
3 ,


1 mn r


~. *,


Figure 53a. Humble Oil and Refining Company, Ray Carroll No. 1, Osceola County, Florida, 8042'-8042%'
The light colored areas are anhedral quartz, whose sutured aggregates are shown well under crossed nicols. The
gray areas are euhedral sodic plagioclase; the black area, right center, is magnetite-ilmenite, with many fractures
filled with green chlorite; the dark mass just to the right of this is chlorite with many small inclusions of leucoxene,
originally magnetite-ilmenite. Ordinary light X15.


.Ar


* ^
i"" '-


J ,i.
''- ~~
~


L:.~J~L~d-,T~il... V


r;'


PMAS*
'7'. A
WhLl IN
























'. V


Figure 53b. Humble Oil and Refining Co., Ray Carroll No. 1, Osceola County, Florida. 8042'-80421'.
The light colored areas are anhedral quartz, whose sutured aggregates are shown well under crossed nicols. The
gray areas are euhedral sodic plagioclase; the black area, right center, is magnetite-ilmenite, with many fractures
filled with green chlorite; the dark mass just to the right of this is chlorite with many small inclusions of leucoxene,
originally magnetite-ilmenite. Ordinary light X15.


r: :5~1~4~:; 1iA


-.i

~~ ~~~~- i


.:,"~?i~'
2~ i-i-


: 'ii~~~*i:-EC~
i .Z -~
-;

~1 ~



~; "i;







BUREAU OF GEOLOGY


OKEECHOBEE COUNTY
AMERADA PETROLEUM CORP.
MARIE SWENSON NO. 1 T.D. 10838'
Completed 1955 Well locality 22 Sec. 5, T. 36 S., R. 34 E.
Center NW.'. N \\
"Top of volcanic rocks 10,750 ft." P. L. Applin (written commun.,
1967).
Reference: Applin and Applin (1965)
9 samples (cuttings) available:
10750'-60' All mostly grains of quartz, anhydrite and more or
*10760-70' less igneous rock, with contact rock ("baked shale")
*10770'-80' fragments.
10780'-90'
10790'-10800'
10800'-10'
10810'-20'
10820'-30'
*10830'-40' "Thin sections
10760'-10770' Thin sections were made of 6 grains; these were basalt,
consisting of fairly fresh calcic plagioclase laths with green chlorite, cal-
cite, and ilmenite; the fourth was perhaps a chilled phase of this basalt
with obscurely crystallized feldspar in a heterogeneous fine grained ma-
trix with much ilmenite; the other two were hydrothermally altered
shale (Figures 56 and 58).
Fig. 54 shows a chlorite-quartz amygdule in the basalt. Fig. 55 shows
another calcitic basalt fragment, not amygdular.
10770'-10780' Thin sections were made of 8 grains, all basalt, some
amygdular. Figure 59 shows an amygdule consisting of quartz and chlor-
ite. The basalt consists of plagioclase feldspar (reddish in thin section),
chloritized amphibole, chlorite, with much rather coarse black ilmenite.
10830'-10840' Includes 6 thin sectioned grains, all but one basalt sim-
ilar to the preceding. The other consists of chalcedonic quartz with pale
greenish chlorite or clay mineral with calcite and black ilmenite; per-
haps hydrothermally deposited. Figure 60.


OKEECHOBEE COUNTY
SUN OIL CO.
AMERADA PETROLEUM CORP.
HARRIS-HOLMES NO. 1 T.D. 9840 ft.
Completed 1966 Well locality 23 Sec. 8, T. 33 S., R. 34 E.
"Top of rhyolite porphyry 9682 ft." P. L. Applin (written commun.,
1967).
No specimens available.







BULLETIN NO. 55


Amygdular basalt
Figure 54. Okeechobee County, Florida, Amerada Swenson No. 1, 10760'-10770'.
Amygdule, consisting of quartz and chlorite. The basaltic matrix is
obscurely crystallized with much ilmenite. Ordinary light X150.




Full Text

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INTRODUCTION This r eport d e scribes in d e t ail a ll th e co r e s and cnttin gs availabl e from a large co ll ec ti o n of w e ll s which w e r e drille d in th e F l o rida Coas t a l Plain, which penetrate d ro cks o l d e r than th e Late Cretace ous Tuscal oosa Formation. It summarizes th e lit e r ature concerned with t hes e rocks. A similar account of th e corresponding rocks in G eo rgi a was give n by Milton and Hurst ( 1965 ) The Florida r oc k s have r ece ntl y been lis t e d and briefly described by Mi lton and Grasty ( 1969 ) The specimens d esc rib e d numbe r seve r a l hundre d from 27 drill h o l es i n 21 coun ties over most of F l orida north of Lak e Okeechobee, and include nearly all of th e d e P t e sts th a t have p e n etrate d i g n e ou ro cks of th e base m ent durin g a half century of dri llin g To th e south of L a ke Oke e chobee, wells have b ee n d rill e d t o great e r d epths, but only t wo have reached rock of pre-Meso zo i c age, o r of i g n e o u s-m tam o rphi c c h a r ac t er." Although many w e ll s h ave b ee n drille d into th e Florida pre-Cretaceous basement, and Pal eozo i c strata have b ee n r ecog niz e d wide l y in th e northe rn part of th e sta t e, th e nature of th e trul y m e tamorphic bas ement unde rl ying Paleozoic sed im enta r y ro c k s s till m ay be co n s id e r e d v irtu ally unknown. Twenty-seve n w ells have p e n etra ted ign eous o r m e t amorphic r oc k s whi ch appear mos tl y to b e e ith e r M esozo i c of Pal eozo ic intrus iv e and r ela t e d vo l canic sediment a ry rocks or contact-me t amo rphi c r ocks a ff e c t e d by s uch volcan i c activity. Becaus e drilling gener a ll y was t e rmin a t e d when suc h rocks were p e n e tr a t ed, littl e or nothing i s known of what may unde rli e th e m or the e x t ent and thic kn e ss of th e base m ent r oc k s th e ms e l ves. "Editor 's Note: Those are Humble 0 & R Co. 1 o. 1 L e hi g h th e di scovery w ell of L e h igh Ac r es F i e ld in Lee County, which bottomed in d i a b ase, and Mobil Oi l Co. No. 1 22-4-B F.S.L., a dry ho l e drille d about 6 mil es W of Engl ewoo d in th e Gu l f of M ex ico. This well bottomed i n rhy olit e Ag e d e t erminations b y potassium -ori g i n p e rcentages i n dicate lat e Tri ass i c o r early J urassic intrusives for b o th d iabase a nd rhyo l it e recov e r e d 111 cores from th e wells 1

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.. 2 BUREAU OF GEOLOGY The p etrog raph y of basement0r ock from 27 Florida wells is desc ribed ( T ab l e 1); a l so some 1 4 iso t opic datings from 6 wells in Florida and 3 in Georgia (Table 2); and c h e mical a n a l yses of r oc k s from 7 F lori?a we ll s a r e given Figure A is a map of F lorid a s howing th e l ocations of th e 27 we ll s an d the co unti es in w hi c h they wer e drill e d. Eight we ll s in Table 1 not li s t e d b y Applin ( 19 51) a r e named and locat e d unde r R e marks," w h e r e the source of information a lso is indicate d. Th e collec ti on of specimens descr ib e d in this r e port tog ethe r w ith 125 thin s ec tions, h ave b ee n d e posit e d with th e Florida Stat e Bureau ofGeol ogy i n Tallahass ee. PETROGRAPHY OF FLORIDA IGNEOUSMET AM ORPHIC ROCKS The ign eo us rocks of Florida and sou th e rn G eo rgia in c lude a (prob abl y) tim e -r e l a ted g r ou p of diabases basalts and rh yo lit es that are present from the stat e lin e south as far as L ake Ok ee chobee. Th eir K-Ar datin g from 89.3 2.2 to 183 10 m.y.-indicate a Mesozoic age, and th e vo l canism i s pres umably cor r e l a ti ve w ith the widespread M e sozoic vo l can ism of th e North Ame rican Atlantic seaboard and the Gulf Coast. Thes e Florida ign eo u s rocks appear t o b e a sou thward continuation of th e rocks p enetrate d in sou th e rn G eo rgia (Milton and Hurst, 1 965). In G l ynn County, G eo rgia, just n o rth of well No. 1 ( Tabl e 1 ; Fig. 1), whic h was drill e d into diabase, th e Humble Oil and R e fining Co. No. 1 W. C. McDo n ald p e n etrated granophyre from 4,732 to 4,737 f t Grano ph y r e com monl y is found as a borde r phase, normally a t th e t op, of large bodies of di abase. In Cli n c h County, G eo rgia, Timbe r Pro ducts Co. No. 1 Wil ey P. Ballard Jr., p enetrate d amygdaloidal basalt from 4,210 t o 4,232 f t ; Brady B e lch e r e t al. No. 1 L e m Griffis p e n e trate d rhyolit e and w e ld e d tuff from 4,348 to 4,588 ft. In con ti g uou s Echols County, G eo rgia in Hunt Oil Co. No. 1 Sup e rior Pin es, dia bas e intrudes Pal eozo i c b l ac k sha l e from 4,115 t o 4,150 ft (a pprox. ) Table 1 and Figure 1 show the prese nc e of very s imil a r rocks in th e nmthern Florida counties. "The term "basement" i s used various1y by different writers; for the plllposes of this report, we d e fin e it as crystallin e, igneous m etamorphic and unmetamorphosed se di mentary rocks of earl y Pal eozo ic or o lder age, unde rlyin g unme t a mor p hosed ( post Paleozoic) sedimentar y rocks that may contain oil o r gas. Some Paleozoic and post Paleozoic -pre-Cr e taceous sedimentary rocks in Florida a r e intrude d locally by ig neous rocks some of which h ave been dated by radiometri c m e th ods and a r e describe d in this report. Unquestioned regionally metamorphosed rocks (e.g., mica, garnet staur o lit e, kyanite, sillimanite sch i s ts, or marbles) h ave not been found in Florida.

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BULLETIN NO. 55 3 Baked shale Figure 1. Columbia County, Florida, J. P. Cone o. I, Humble Oil and R e fining Company, 3520' -3529' Top 7 fe e t Carbonac eo us s hale, with disseminated andalusite (?) Ordinary ligh t X22.5. The association of diabase or basalt, tuff, rhy. o lit e, and granophyre is so characteristic of many regions of the world that it does not re -quire e mphasis here. These rocks are found as far south as Okeechobee (e.g., basalt in St. Lucie County on the east coast, basalt and rhyolite in Highlands County in southern central Florida, and rh yolite in Hillsborough County on the west coas t). Evidently Mesozo i c volcanism extended across mos t of the state. Bass (1969) refers to "The two wells known to penetrate basalt, the

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.. 4 BUREAU OF GEOLOGY (Hardee County Humble) K ee n and ( Highl ands County Humble) Carlton" as th e southernmost ... "and sp eculates as to a distinct province of mafic e xtrusiv e rocks in south e rn or southwestern Florida ... which may b e considerably younge r tha n the rh yolitic rocks ... However, it may b e note d th a t basaltic ro cks exist in northe rn Florida ( Milton and Grasty, 1969 ) not to m e ntion G e orgia ( Milton and Hurst, 1965 ) The terms "diabase" and basalt are us e d in this r eport with the that th ey may in som e cases r e f e r to ess entia lly th e sam e rock, c rystalliz e d unde r vary ing conditions from th e same body o f magma. The chill e d uppe r margin may have a basaltic aspect, whereas th e more s lo w l y coo lin g d ee p e r magm a ma y have the diabasic (ophitic) t e xture. Similar considerati ons appl y as to Gough' s ( 1967 ) g eo physically-based int erpretation of a northeas t-southw es t "Appalachian" b e lt of volcani cs, some two hundre d kilom e t e rs wide, across Florida, through the Gulf of Mexico to th e Camp ec h e region ; the northe rn boundary of this belt i s h eld, following Ap plin ( 1951 ) to divid e Silurian and Ordov i c i a n sedi m entaiy rocks from rh y olitic lava pyroclastic rocks and granit e-diorite. B ass cites the two basalts m e ntion e d above as part of such a b elt. All this sugg es ts the futilit y of basing broad conclus ion s on meager data. In central Florida, anoth e r group, giving much earli e r date s includes m e tabasalts in Volusia County, "granites" or "al as kit es" in L a k e and Orange Counties, "granite" and "diorite" in St. Luci e County, and m e tabasalt in Hillsborou g h County. Age determinations on thi s group range from 226 6 (or 224 3) m.y. through 308 5 m.y. to 480 100 (? ) m.y. or from Early Triassic or Late P e rmian through Middl e P enn sy lvanian to E a rl y Cambrian. In two w e lls volcanic rock overlies m e tamorphic rock t y p es-in St. Luc i e County b asalt ov e rli es "granite" and diorit e," and in Hillsborough County rh yolite and w e ld e d tuff overli e m etabasaltic agglomerate. The !:elation of th e basalt overlain by unalte r e d Upp e r Jura ssic or Lower Cretaceo u s s e dim e nts ( Applin and Applin, 1965 ) in St. Luci e County to the "granite and "diorite" just b e low is an tmsolv e d problem. I s th e basalt a flow ov e r a granite-diorite floor ? The age of th e basalt, whic h is similar in ge n e r a l appearance to other presumably M eso zoic southeastern basalts has been d e t e rmin e d (89.3 2.2 m .y = L a t e Cret aceous), but th e unde rlying "granite" h as b ee n date d as E arly Tri assic and the "diorite" a s Early-Middle P ennsy lv a nian (Table 2 ) These two disparate ages, ho wever, may r eflec t d e creas in g th erma l m e tamor phism downward from a basalt flow with co rr e spondingly diminish e d argon loss as demonstrated by Westcott ( 1966 ) Diffe r e ntial argon loss due to the degree of alte ration of th e dated s p ec im e ns a l so could caus e the variation in ages.

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No. ( T able 1 ) Locatio11 O p e r a t o r W e ll 24 26 ] f) H ig hland s Count y, Florida Humble Oil and R e finin g Co. N o. 1 G. C Carlton E s t a t e H a rdee County, Flo rid a Humbi P Oil and Rtfinin g Co. No. 1 B T. Keen St L u c i e Count y, Fl or i da Arnerada P etro l eum Co. No.2 C o w les Magazinl' Table 2 .-Isotope dating of Florida (and Georgia ) rocks. Depth of S a111ple (jl) 12,661 12, 73-1 12, 74-1 12,7-14-8 12, 7-18 1 2,7-14 12:148 Vol of H.adiOP,CIIiC K20 1-\r}.!on-..JO % r'm"' l t g sample) 0 3 0 8 0 007 1.96X w-:J 3 -WO.Oi5 1. 7 1 X w-t 1.77X10-2 2 0 8. 5 O.O.JH 3.59 X .10-2 2.29 o .o1 1.79 x ro -2 1.so x w 2 1.24 o 01 l.-18 x w-2 '7,-A t mos. Contan1. 19.0 H 2 11.2 39.4 13.5 10.3 10.-1 Age a n d Erro r (111. u .! JH3 1 0 1..J3 7 14 7 :: 3 89.3.2 399 1-18 5 3 0 470 503 226 6 22-1 :: 3 3 0 8 s Remarks H.G-1 Ho<.:k is ve t ) f ined-grai nl'd h o locryst a l l in< b as alt. w ith ran phl:'nocr ys t s o f p lagi oclasP. Cont ain ..; GO p t r cl'nt fr<'.Sh fl'ldspar 2.5 p e rcent cl oudy dino p y roxen<'. and 1 5 p e r ce nt o liveg reln -hrown Sl'rpPnt-i n e afte r o li v inl't ? ) S li g htl y alte r ed. \V h ol< rock Crast y HG-2. VC'r y finc g r a inC'd b asa lt whic h h as suf f c n cl low-gr a d e m e t a m o rphi s m with n o fresh fC'lds p a r a n d all m afi c mine r a l s c h l oritized Hi g hl y alte r !' d : Who l e rock. Gras t y B asalt, d ark-gray g r anular r oc k w ith calcite hiC"h s up t o seve r a l millirne t e r s acr oss. Oiaha s i c lt""'xture; mostly p l a g i oclase l ath s w ith l a r gt' oliv incs compl e tel y r e p laced b y bluis h g rf'{'11 c hl o rit e and or e grai n s S o m e calcite rep lacin g p yroxe ne(?). W h ole rock Grast y C hl oritiz<'d biotite K -Ar Bass Plagi o clase C hloritized biotite Hb/Sr 1-lornb!Pnde K -Ar R G 8 Roc k has acid compositio n and g r anite t<'xture w ith f O p e r c('nl quariz, p e rc<-'nt bio tite, and 3 0 p e rcent plag i o cl a s < o f whic h : J 0 5 0 p{-'r c cnt h a s been a ltf'rl'd t o sericite. B iotite s h o w s slight alteratio n t o c h l orite Quite alte n d Who l e r oc k. Gra s t y. RG -9. Dio .rite with 20 p e rcent quartz, 3 0 p e rcent br own-green h o rnbl ende, 10 p e rc e nt pa l e br own bio tit e associat e d with h o rnbl ende, and 3 0 p e rcent fresh p lagi oclase. Hock i s fr es h. Who l e rock. Gras t y CJl CJl

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Table 2. (Continued) No. (Table 1 ) 20 21 1!; f.Oc(J/ion Otu rntor \I'd/ Deplll of Sam1i< (j'l) O;t tnla Count), Florida 8,71> I llundJIP Oil and R lfining Co. I llayman o,ctula Counh. Florid<\ 1>,0-12 1 Humblt Oil an d flpfimn)( Co. Carroll l\o. I Vol u s ia Countv. l "iorida .=J,H5.1-.=),H.5 I Sun Oil Co. Xo. J Po" ell Land Co. .3,H5 3 3 -.3,9.3h 5,951 .5,955 \lot of Rndiol{euic K20 \r/!,011-IO (1111>13//!, of .wmple) !5.32.01 .\litdwll Count), Ctorgia Stanolind Oil and Ca; Co. ="o. l. }. H. Pullt n 7 :3/.3 0 .5.58 tl.OlO x w-a Atmch. Cn11tam. J H,(; -1/ =j A/!,e mad t :rrnr (11/. y.) 17:3 1 .BO 631 15!-J 521 Rl"mnrks H G 1 I Hhyolitic lull' with vtt y l-ine-graint.d matri>. prnb.tbl) of quart'/ and ft ldspar. Contam.., roundc'tl crystah. e nO<. 'r) '" or nHnt' of ( n r) common) quarf'l, (common) nltt>n d a lkultt fr 11<\Ss K20. 0.93 Jlt'rctnl. K4 0 ppm ll.'n. Ar40 ppm 0.0302, radW)(< nic Ar1 0 9 2 Ar40/K 10 0.0.12.5. A !(t' I H O m.)'. (AgP ma) ht low h) 20 rwn .. ln t or m o r l' o f vari n h l( l't'ltntivity o f K -hla.rin)! mint:'rab of II. rrwm .,, H Manin. 1' Elmore. rnft'i> bio i ite llb/Sr Bas. llurnblt.ndt indiorite K-Ar Biotite indio rilt. hornfl'l:-t K-Ar Bass 393 llornblt'llde indiorit<' hurnft'l s K-Ar 1 2.5 HC-:3. Dio1b1ht sho" ing typical dark auJ,tit a c p y ro xl' nc, and li!(ht pln!(inclasP ftldspar. llo loc r yslullinc, f're<' o f altPration. Vt r y fresh roc:k \\'ho lt rock. Cra,ty.

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Table 2. (Continued ) No. (Tabl e 1 ) Location Operator Well Echols County, GPorgia Hunt Oil Co. No. 2 Supt>rior PirH' s Chattahoochee County, GPorgi a CusS4.-'t a (water w e ll ) Depth of Sample ( { I ) 1,130 1 ,2001,205 Vol. of HadiOJ.! '1lic K20 1\rJ!,on-..JO ry,! (n1111a/g of sam fJ/e) O.H 1 3 0 037 5.-12X 10 :s 0.-13 0 .007 -1.69 X 10-: J '7, AI OHM. Cnnlam. 61.7 67. 5 1\g'<' and Erro r (111.u. l!H 1.5 llemarks HC-5. Hof..'k ehips from sarnl' roc:k t y p e hut with ont finc'-$-!rainl'd phasP and on<' m edium grained phast'. r Jay h< fr o m c:hi l h d margin and coarser g r a intr! inl:>r i u r o f <'it h<'r d i kP o r flow or, m o r<' a basalt and a d i abasE'. F ineg r a ined phas h c ts 20 P<'T<.:<'nt plagioclase phenocrys t s matrix o f g r ai n e d opaques and pyrox<'ll<:" ('?) with nC'edles o f pla g i o cl ase' and SOillt' idcling:sitc a ft e r o Jivinf' e). Thi s ph.\se i s s li)!htly al t erC'cl. The m cdium phas<' ha!a d iabas i e texturt> \vith 3 0 fn ... s h plagi odase, -tO augit(', and 1 0 percent int<>rstitia l iddingsit c a ft e r o l i vine (?). Opaques occur as accessories. This roc k i s slig h t l y a l t e r P d with 1 0-20 pcrc.:C'n t matt'rial which i s probab l y dt v i trifi c d g lass. W hok rock. G rasty. 3 0 3 1.5 HG-6. H ornbl<>ndit< con s i s t in g esst n t i ally o f 6 J ue-green hornblende, clear quartz, cloudy a l kalic f eldspar, b rown biotite, and p a lc-gn--'en c h l orite. Rock was run as hornbl ende separ at<._. o f 70-1 2 0 mesh Whol e ro c k. Grasty. Tabl e 2a. Age d e t ermina ti o n s A m e r a d a P etro l eum Corp Cowl es M ag a z in e No. l S o u11plt D pth 127:)-1" 1 27-11" 127-IH" Basal t (;ran itt' Chloritized hio tit< from :-.c:his t and (Juartz cli o rit<" }.!n t' iss P l a}.!ioc lase f rom quartz diorik gneiss Oiorit p Hornhhnclt in diot ilt (nmphiholi tt') Analyst C:ras t y Grasty Bas:-. M d hod K A r 1HJ 1 2 m .y. 2:2li :t: fi m .y. : :J m .y. SrH7/S r H(i 530 m.y. K:Ar 31J>J m.y. m.y. 30H m.y. -170 m y. .50:3 m.y.

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8 BUREAU OF GEOLOGY Another que stion is whethe r the "granite s" of Florida are r e ally gran it es, or arkose alte r e d by contact m etamorphism. Altered s edimentary rocks are w e ll known in regions of Triassic volcanism in many localittes in the eastern Unite d States; the y are associated with major tectonic disturbance s that exposed large volumes of granitic rocks both to rapid e rosion, and, in pla c e s to alteration. The "granite" in the Pierce County, G e orgia, Adams McCaskill w e lls (Milton and Hurst, 1965 ) may have such a history. Furthe r granophyres of superficiall y granitic aspect and composition are w e ll known as differenti a t e s of large diabase bodies, and many of the so-call e d "basement granite s in Georgia strongly suggest a granophyric origin (e .g., Glynn County, Georgia, Humble Oil and R e fining Co No. 1 W. C. McDonald) No unambiguously metamorphic ro cks-such as mica schist garne t schist, chlorite-kyanite -sillimanit e schist or marble-have b een foun d in Florida. The ro c ks terme d "granite or "diorite" may b e contactm etamorphose d s edimentary rocks or thermally altered phase s o f igne ous intrusives. Whether or not drilling in Florida has p e n etrated a truly metamorphic basement of or e v e n e arly Paleoz oi c age is, in our opinion, still an ope n question. DATING OF FLORIDA AND GEORGIA IGNEOUS-METAMORPHIC ROCKS The K-Ar dates in T able 2 w e r e d e t ermine d at th e Univ e rsity of Toronto by Robert Grasty and M. N. Bass (1969), with th e e xc eption of that for the Volusia County, Florida, homblende diorite or m etabasalt, which was d etermine d at the U S. G eological Survey. For the ro c ks date d by Grasty, duplicate potassium d e t erminations were made on sample, with lithium a s an internal st andard and sodium a s a buffe r. Argon extracted in a bakabl e glass fusion s y st e m was mix e d with "spike" argon-38 and analyzed by an MS 10 mass spectrometer, as d escribed by e t a!. (196 4) Six m easurements of th e argon-isot o p e r a tios w e r e made on each gas sample The limits o f error a r e standard d e viations d educe d from the e rrors in both the potassium and argon m easureme nts. In th e Unive r sity of T oronto laboratory, the standard d e viation of r epeate d measur e m e nts on th e same s ample is g e n e rally l e ss than 2 p e rcent and analy s e s of interla b oratory s t andard samples show tha t syst ematic errors are also l e s s than 2 p e rc ent ( Baksi e t a!., 1967 p. 63 06). R e p eat m easurement on RG-2 and RG-S c onfirm e d this a ccur acy. Consta nts us e d in the calculations a r e ;>.B = 4 .72 X 10 -10 y r -1 A.e = 0.584 X 10 tOyr-1 K40 = 1.19 X 10 -2 ato m perce nt. T h e K A r ages range from Late Cre t a c e ous to Early Ordov ician o r Earl y (?) Cambrian. Except for the younge st and th e thre e o ldest the a ge s

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BULLETIN NO. 55 9 are within a r ange from L a t e Jurass i c to E arly Triassic. Th e two d a t es ( middle Carb o nif e rous ) for homblendite fro m Chattahoochee County, Georgia, and diorite from St. Luc i e County, Florida, are s imil a r t o d a t es from lat e Paleozoic vo lcani c r oc ks r ec ogniz e d e ls ew h e r e in th e Appala chians. The yo un ges t ag e whethe r o r not va lid 89.3 2.2 m.y is by no means the youngest to be r eporte d in th e Applachian r e gion ; Fullagar and B ottino ( 1 968) g iv e a T ertiary age ( 30 1 5 m.y. ) for f e lsit e from Hi g hl and1County, Vir ginia. The o ld es t age, 480 100 (?) m.y. (or 524 m.y.) from Volusia County, Flurida, m e tabasalt," i s within the range of the Cambrian to Ordov i c i an age of th e .\Torth Carolina Slate B elt" rh yo lit es d e t e rmin e d by Hill s and Butler ( 1968 ) Some wo rk ers have r e f e rr ed th e Georgia-Fl orida volcanic r ocks in part to th e "Sl a t e B e lt series. Three ages obtained by Bass ( 1969 ) on samp l e s from Humble Oil and R e finin g Co No. 1 Carroll, Os ceo l a County, Sun Oil Co. No.1 Pow ell Land Co., Volusia County, and Amerada P.etrol e um Corp. No. 2 Cowl es Magazine In c., St. Luc i e County, are r e s p ective l y, 530, 524 530+ m. y The se d e t e rminations indicate a Middle Cambrian age. The K-Ar and Rb/Sr dates of Bass ( 1969 ) cited in Tabl e 2 are disc u ssed in d etail in hi s p a p er. CHEMICAL ANALYSES OF FLORIDA IGNEOUS METAMORPHIC ROCKS Tabl e 3 g i ves the c h e mical com po s ition of 11 Florida i g n eo u s-m e tamorphic r oc k s B eca u se th ese r e sults are hom sma ll and ge nerally isolat e d spec imens th eir present va lu e i s limit e d ; h oweve r as more inf o rmation on th e F lorida subsurface b ec om es availabl e, comparative studies may b e found useful. The ana l yses h ave been compute d in t e rm s of norm a ti ve min e rals, in Tabl e 3a This oft e n g iv es a somewhat clearer picture of wh a t m eaning th e anal yses ma y h ave, a lth o u g h it mus t b e emphasized th a t th e data prese ntl y availab l e is a ltogeth e r insuffi c i ent for any m ea ningful ge n eralizatio ns. To illustrat e thi s w e may compare the anal yses or rath e r th e norms 9 and 11. or volcani c as h and rh yo lit e, r es p ec itv e l y, from Putnam County and Hlll .sbo rou g h County, 150 mil es a p a rt. The two norms are indee d s i mi l a r h1g h nonnative quartz, substantia l nonnative corundum orthoclas e, and a lb ite pl ag i oclase; normative h e m atite an d magn esite It would appear th a t th ese tvvo rocks a r e part of one body. Y e t a second sp e cimen of th e Hillsborough County rock an a l ysis 10 unquestionabl y from th e sa m body, shows n e ith e r norma tiv e quartz nor corundum, strongly cal c i c pl ag ioclas e, much, n o t littl e, mafi c min e rals and n e ith e r h e m atite nor magn esite. Agam, the two v e ry similar a n a l yses of diabase, 5 and 6 from Taylor

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Table 3. Chemical Analyses of Florida lgneous-Metamorphic Rocks' : 2 3 4 .5 6 7 R 9 10 11 Si02 63.7 -!6.8 68.7 .57. 0 50.9 .52.8 .51. 7 57.1 73.3 -18 .. 3 59.1 A I203 15.1 17.1 1.5.4 16.8 16 6 1.5 3 17.3 13.9 1 3 8 l 1.0 1 3. 0 F e203 3 3 3 .5 .7-1 .3.0 1 .. 3 2.2 10.2 -1.1 2.5 3 .1 3.8 F P O 2.6 6.1 2.6 -Ul -1.6 .72 3.-1 .5I .5.7 1. 2 MgO 3 3 10.5 3.0 5 6 69 I.-I 3 .1 7.2 .93 9.2 3. 0 CaO 1.1 3 .2 3 .7 6.8 6 .. 3 8 9 .5 I -1.3 .02 8.3 -1.1 Na20 3 0 1.2 1.9 1. 6 3.3 2. 5 1. 1 2.7 2.-1 1.5 -1.3 K20 2.6 3.3 .95 .90 .57 .68 5.5 2 .2 3. 2 3 .1 3.6 H20-. 3 2 .:55 .1-l .06 2.5 .-16 3.5 3 7 -!3 l.l 3 5 H2o+ 2. 9 5.-1 2.1 1.9 U l 1.1 3.6 2. 1 1. 7 2. 9 .1.5 T102 .62 .83 1 5 .7-5 1. 2 1.1 1. 2 .73 .. 3 2 .94 32 P205 .20 1 2 .28 .28 1 7 .17 .36 .22 .08 .16 .01 MnO .11 .ll .07 .17 .08 .22 .07 .J1 .03 .19 .23 C02 .7.5 .52 <.05 < .05 .-16 < .05 .15 .-1.5 <.05 .9.5 6.1 Sum2 100. 89. 100. 100. 100. 100. 99. 99. 99. 99. 98. Powder d e n s ity by sink float 2.72 2.72 2.72 2.80 2 .60 2.95 2.52 2.80 2.72 2.80 2.70 1 Analyses b y P a ul Elmore, L ArtiS, s. B otts, C. Chloe, H. Smith, I K e lsey, a nd J. Glenn, U. S Geological Survey. u sing m etho d s clescrib<>d by Sh apiro and Brannock ( 1962) supplemente d by atomic absorption techniques. 2 Rounded to neares t whol e number 3 F o r location, l a b. n o an d r e mark s see b e low. Analys is No. 2 3 -l s 6 W e ll Loc a/.it y (Fig 1 ) 21 1 9 19 19 5 5 Lab. No. W168611 W168612 W16861 3 W16861-l W1686J5 W168616 Rentatks Osceol a County, Florida; Humble Oil and R e fining Co. No. 1 Ra y Carroll; 8, 0.31-8,0-12 n. "Al t e r e d and v e in e d bioti t e granite'' ( F F Crout in Applin, 19.51 ) Po ss ibl y hydroth ermally a lt e r e d a rkose !C. M.) (Fig 2 c) St. Luc i e County, Florida, Am erada P etroleum Co. 1 o 2 Cowles Magazin e, amygdaloiclal ba salt 12,73-1 fl. elat e d 89.3 2.2 m.y. (Fig. 2d). "Granite," 12,7-l-1 fl. clatt>d 226 6 m y. 22-1 3 m. y ( F i g. 3a). "Diorite," 12,7-18 fl. elat e d 308 5 m.y. (Fig. 3b). Taylor County, F lorida. Humble Oil and R efining Co. No. 1 C H Hodges, 6 ,162 H. diabase. Dia base, 6.216-6.21 9 fl.

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II d/ ,\,nlrtsi.\ l.rwnllllt l ,o/J .\'o No. IJ 7 ); \\ 11>'>6 17 ICI \\ I(; 61 f) II \VIIlllll lfl 10 27 \\ lll!oO(i:!O II 27 \\ I 6"16:! I l ... Qunr t z : ), 1 /lf ) orundum I 7 .22 I '\.:l(i I lfl'j(JI Albr!t H.l 10. 13 I II. 01 t o nil<" t::n l.tlrt .()(16 26.130 l > rr.xrlitt' 1 22'1 7 111 F or-. l t r it Fu)lll l t t 1.7/l 5 .';,()75 lltmntrll lim nah I 17 l .:;;r; Rutrlt \patti 171 :! ;tkr!t I I'J 'l I I .179 Sa l le ifJ. O lfl 5 1 ,li75 F \1m i c 'JCJ.:J f)20 91.-7 1nd othe r t o t Ill ur, B"un: Table 3. Coutmunl) \ulu"a Count) Flurtd.t un Orl Cu. :\n. I l'o,HII Lund Cu. >.'IHJ-.3.11.:!1 It ''\\r.tllwnd" 'nlt..uuc.: rO<:l. flU\\ l'l.tfotl<'r llnntl.t llumblt Orl tntl lkfmrnl( n. '\u I J \\ Camplxll, l h.:!l 1.626 n lhclrotht>rmall) .tllt rr d h.h.th and rh)ulrtr tuff l'utn.tm County, Florrdu. un Or I Cu '\u I II. E. \\'t,thury 1'1 a/. : l.li7fJ ., J Iili I fl \ o lcanr c oh lit II horough uunl) rlnrida. Humhlt Otl ohte or "dtkd tufT llh 10. 1 H 1 0 LH n Table : Ja. Florida igneou m lamor}>hic rod. norm s ..1 .:L .5 !i -10. !)2.1 I fl.7 0fl 7. 1 2 1 (j,!)OI I.(H7 .57l 1 ).:}1 /j J..!Oii 1 01 16.077 1 : 1..; 1 9 17.Hll 21.1.51 16.210 11. :; 'l :21. 2 1 2 .. "5JI .5. 9 33 7 172 1 1.917 1') .111 IO .H. .).570 3 .. 39'7 .1.0(J::! 1.07:3 1.:350 (1. 21.5 .1.1HO .'). 3 I. 1:2 I 2 .17q 2 0 f) .661 >3 .IU:J .103 111 Ill 1.0 Ill .II I 81.12fl 71.771 60.22 I (i0 .591 I :3.7 2() 2CI.OfJ.5 2M. l(i. 3 : 37.611 97. H !17. 1i6(j '11.6')0 Hll.231 l 11. IIUI22 I 1.00\J fJ.Oit ./l2/l 11 'iO I l 'l .IHHI II '> l(i :!Viii I l o:;u 7 l l( i li. 9 l 2 1.911 5 HI '\ 1 0 ;2()() I 1;70 l,.j!;(; .}::!() 3 1 .'i11 II 1 .0:23 I I> 7 1 II' ) (i7 7:):) 2 0 ./l 16 28.7.1 H fl2 1 .)11 fl6 goo 1 .'\.77 6 fi.'3Hii 1/l. fJIO 10. JO'> 1 :202 .fll 1 I. 72 .(iO .096 H 1 .11i2 :';,6/lli H7.070 lQ IIi I I 'I 11 h11 l :2:!.111 1.'111 l l .'il2 3 .711 :2.1 1 .711H 1.1!1!) 1.7 o; 7'J :2 l(jj :; : 1.1:2.1 1:... 127 fl!). l '\ 1 1 1 lffs.12 2.0: ) 0 21.273 "5 02 .).6!)1 1.:!.5. 3 .60 .Oll 3 i .22' .5.602 79 ):!0 I H.27.5 Hll. 7fl .') Tiu norm h bt-tn tumput d '' ith 0 .. lnd t.ou. h t u .UO t o (''Om f o rm w&th tiu-pr()Jr!ram

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12 BUREAU OF GEOLOGY County, r e f erre d to above (pages ) do show d e finit e difference from th e St. Luci e County amygdaloidal basalt, some 250 mil es distant; first being presumably Triassic-Jurassic the second dated as much younger, namely upper Cretaceous (89.3 m.y., Table 2 ) Howe ver, comparing all three analyses of the St. Luci e County rocks, while the three an a lyses (2, 3, 4) are remarkably simil ar, their isotopi c ages are widely disparate. Thus w e m ay conclude by observing that the valu e of these analyses is for the present limited to what they may contribute to the understanding of the individual rock specim e n, and that attempts to us e them for broad cor relative purposes are futile. DESCRIPTIONS OF FLORIDA "BASEMENT" ROCKS NASSAU COUNTY ST. MARY'S RIVER OIL CORP. HILLIARD TURPENTINE CO. NO. 1 4824' T.D. Comple t e d 1940 Well locality 1 Applin (1951) No. 67 Triassic diabase in Paleozoic shal e Cole ( 1944 ) reports that this well was begun in 1936, and compl e ted eight years later at a depth of 4817 f eet. He briefly r eviewed ea rli e r ac counts by Campbell, Schuchert, and Munyon, and discussed ex t e nsively the microp aleon tolog y of the well. He also considered in detail th e non fossiliferous rocks below the marine sediments (Uppe r Cretaceous Tuscaloosa). Below the Tuscaloosa which in this well consi sts of 380 feet of gray, hard, calcare ous and glauconitic sandy shale, with shark' s teeth, is 1.55 feet of dark gray, hard shal e, d evoid of fossils, followed by diabase to the bottom of the well. Applin (19.51) states that the diabase underlies Paleozoic black shale later confirm e d by paleontologic studies by J. Bridge and J Berdan. Cole, after considering a ll the evidence, observed, "It is th e opinion of the writer that the section from 4640 to 4795 (the 155 feet of unfossili ferous shal e) r epresents a non-marine phase and that the age of the rocks is Triassic. The writer beli e ves that th ey a r e equival ent to the Newark ser i es." As for the diabase which intrudes the shale a study b y T. Osborn Fuller, cited at length by Cole, convince d him that it is of Newark (Triassic) age. Nevertheless, Applin (1948) referred to the publishe d data as "confl ict ing and inconclusive" but correctl y included the well as among those which entered "Pal eozo ic black sha l e." Berdan (written communication, May 1970) states that "a sample of

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BULLETIN NO. 55 13 rather large chips of dark gray shale from a depth of 4700-4800 feet con tains a small fragment of eurypterid integument which shows the characteristic scales of the genus Pterygotus. This genus ranges from the Ordovician into the Devonian. However, a core of dark gray shale from Sun Oil Company J. H. Tillis No. 1 well in Suwannee County also contains Ptery gotus, which was considered to be Silurian in age by Kjelleswig-Waering (Jour. Paleont., v. 24, no. 2, p. 229-231, 1950), who described it as P. Jlor idanus. It seems probable that the shale in the Hilliard well is correlative with that in the Tillis well, and is also Silurian." Two thin sections of the diabase, one from 4818'-4819', the other 4823' are both fres11 unaltered diabase; the lower one is somewhat more fine grained. COLUMBIA COUNTY HUMBLE OIL AND REFINING CO. J.P. CONE NO. 1 4444' T.D. Completed 1949 Well locality 2 Applin (1951) No. 42 Diabase in Paleozoic shale Applin (1951) lists six occurrences of diabase and amygdular basalt sills in black shale of Paleozoic age at 3529'-3562' 4193'-4195' 3564' -3565' 4248' -4251' 4191' -4192' 4267' -4270' Cores are available from 3520' to 4281'. Core 115 3520' -3529' recovery 8' Top 7' is gray carbonaceous (burns white) shale, with pyrite and a little sphalerite along bedding planes. Microscopically the shale is seen to contain innumerable clear colorless sericitic grains, with rectangular or hexagonal cross section (Figure 1). Most show concentration of the dusty shaly matrix material in the interior of the grain, with clear borders; this suggests that the grains may be sericitized andalusite, in which such seg regation is normal. 1' is at the contact of black shale and underlying diabase. It is a hght colored fine grained rock with calcite layers and numerous small rounded pyrite nodules. In thin section (Figure 2) the rock is seen to almost wholly of plagioclase laths and calCite (replacing augite?) and pynte (replacing iron-titanium oxide?). Core 119 3541' -3543' top part of core is hard fresh diabase. 3543'-3555' top part of core. Is a perfectly normal diabase, with typical mineralogy calcic plagwclas: laths and subhedral augite; with minor black ilmenite grains and greemshchlorite (Figure 3).

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14 BUREAU OF GEOLOGY Alt('red diabase Figure 2 C olumbia County, Florida, Humble Oi l and R e finin g Company J. P. C o n e No. l 3 5 2 0 -3 529' Bottom foot of core Shows (white) plagioc l ase feldspar. The dark are as r epresent mo s tly cal cite ( r e p lac em ent of pyrox e ne?) and ( most of large blac k aggregat(' l e ft of c ente r ) pyrite, w hi c h ma y hav e r e p l a ce d ilm enite-m ag n e tit e Ordinary light, X28. 5. Core 121 3 555 -3562 top and bottom of core, hard fresh fine graine d diaba s e No diff e r ent from preceding. Core 122 3562 -3589 Sample hom s econd 10 ft. of core. Gree nish g r ay sha l e with calcit e-pyrite lay e rs ; a l so r e d h eulandite(?) 01thoconic cepha lopods o ccur in this shal e (Roland Brown J. M. B erda n U.S.G.S.). Core 1 4 9 4 1 81'4206 S ample from b ottom of core, a m ygdaloida l basalt. This i s a fin e gra in e d gray-gree n v es i cular rock with ble bs of c oars e white c alcit e up to an in c h across; som e of th e small e r on e s are reddish in part. The r e a r e a lso sm a ll p y ritic s egre g a tions.

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BULLETIN NO. 55 1 5 Diabase Figure 3. Columbia County, Florida, Humble Oil and Refinin g Company J. P. Co n e No l 3543' -:3555'. Top part of co re. No rmal diabase, with typic a l lath s o f ca l c ic plagioc l ase and e uh edral a u g it e b e tween the feldspars. Ordinary light, X28.5. In thin s ec tion, the rock shows a poorly crystallized dark turbid groundmass, in which are strewn in abundance small co lorl ess or faintly reddish au gites. A few of these are larger than the others, and consist of interpe n e trating twins of several individuals. Iddingsitized (?) euhedral olivines are small but nume rous. The more d e finit e l y colored augites are r eddishviolet, show axia l dispersion <1nd are probably titanife rous. The calcite segregatio ns often show an irregular p eriphe ral zone of brown substance, perhaps serp entine, and som e have spherulitic development (Figures 4 and 5). Core 151 4231 4 256' middle third, gray amygdular basaltic ro ck, with irregular calcitic amygdule s

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16 BUREAU OF GEOLOGY A m yg dul a r b asa lt Fi gure 4 Columbi a County, Florid a Humbl e Oil and R e finin g Compan y J P Con e o 1 4 1 8 1 -42 06' Sampl e fr o m b otto m of co r e. Amygdula r b asalt; a t th e l owe r rig h t i s a l a rge amygdul e of r adia ll y fi brous ca l c it e, a t th e uppe r rig ht, a s imil ar amygdul e w i t h o liv e brown se r p e ntin e and ca l c i te The crys t a l s in th e b asalt a r e mostly se rp e ntini ze d o liv i ne a nd un alte r e d a u g ite. Ordinary light, Xl4. Core 1 52 425 6 428 1' S a mpl e f r o m midd l e o f co re. R ecove r y 24' 1 ft. o f core i s lik e m a t e rial submitted, r e m ainde r is bl ac k s hal e'' L o uis e J o rd an ( Sun Co. geo l og i s t now d ecease d ) The sam pl e o f th e 1 zo n e co n s i s t s of t wo somew h a t di ff e rent r oc ks, o n e in contact w ith black s l a t y s h a l e. Th e contact phas e, a b out o n e inc h w id e, i s li ght g r ay-g r een, m a rk e dl y p y riti c and ves i cula r ; it g r a d es into a d a rker more uniforml ytexture d ro c k lik e th e second s p ec im e n whi c h h oweve r

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BULLETIN NO 55 17 Basalt-cal c it e (hydrothe rmal) contact F i g ur e 5. Columbia County, Florida, Humble Oil and Re finin g Company J. P. Con e No. 1 4181 '-4 206'. Sampl e from bottom part of co re. Shows contact of basa lt and coars e (hydroth e rmal ) calc;ite Near th e cente r i s a mass of ca l cite partly e n c l os e d by oliv e-brown serp entin e (The clear area i s w h e r e th e section broke apar t during grindin g ) Crosse d ni co l s Xl4. a l so show s scattere d pyritic-calcit e amygdul es. In thin sectio n the contact shows a poorl y crys t a llized turbid agg regate, with s mall poorly-develope d pl agioclase crystals and no well-d e v eloped augite. There are large ill defined light colo r e d areas with sk e l etal magnetite and thin laths o f brown hornblende. Often th e middle of th ese areas i s cal citic. (Figure 6 ) The darker rock, however, away from the contact is w ell cryst a llized and consists largely of reddishviolet tinte d augite in stubby prisms, som e larger than the othe rs. The r e a r e a l so chloritized o li vin e s and inconspic uous poo rl y-develop e d feld spar in th e groundmass. The f e w l a r g e calcite

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18 BUREAU OF GEOLOGY Amygdular basalt Figure 6 Columbi a County, F l orida Humbl e Oil and R e fining Company J. P. Cone No. 1 4256' -4281'. Sample from middle of cor e Ordinary light, X14. vesicles contain euhedral pyrite and are associated with a colorless iso tropic mine ral possibly analcit e In this well basalt-diabas e sills are found from 352 9 to 4281', or through about 750 feet. Th e sills are intruded into 962 fee t of fossiliferous black shal e conside red to b e Late Silurian or Early Devonian in age (Berdan and Bridge, 1951 p 69). The association of t ypical diabase with typi cal basalt suggests that the two rock types r eflect differences of physic a l conditions under which th ese bodies crystallize d from a common mag matic source

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BULLETIN NO. 5 5 MADISON COUN TY HUN T OIL COM PA N Y J. W GIBSON NO. 2 538 5 T.D. 19 Completed 1 9 4 5 Well locality 3 Applin (l9Sl) N o 62 Diabase in Pal e ozoi c shale Igneous r oc k was not noted by Applin ( 19Sl) but cuttings from 5200'.5210' are g r eenish granular diabasic rock. It appears to be weathered, but microsc opic examination indic ates hydrothermal alteration rathe r than weatherin g Calcite and bright gree n chlorite are abundant; very little feldspar r e mains, it being repl aced by fin e graine d s erpentinic or chloritic material. Black magnetite grains are numerous. Figure 7 shows the microscopic aspect of this rock. F igure 7. Diabase (hydrothermally altered) Hunt Oil Company J. W. Gibson No. 2, Madison County, Florida, 5200'-5210' (cuttings) This is volcanic rock, still showing original texture though the constituent minerals have been altered considerably. Ordinary light, X28.

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20 BUREAU OF GEOLOGY The rock is a hydrothe rmally alt ered diabas e A cor e abov e it at th e d epth of 5154-5162 f ee t, is dark gray shale containing th e trilobite Colpo coryphe exsul Whittington, 1953 which is consid e r e d late Early or e arl y Middle Ordovician in age ( Berdan 1970 written communication ) TAYLOR COUNTY GULF OIL COMPANY BROOKS SCANLON BLK. 42, NO. 1 5517' T.D. Compl e t e d 1949 W ell locality 4 Applin ( 1951 ) No. 8 2 Diabas e -basalt 5438 -5517' T.D. is diabase, probably a lava flow. Unde rlies clasti c rocks of Triassic (?) or Jurassic ( ? ) ag es." Applin ( 1951 ) Specim e ns from Core 39 5448 -5453 ( recovery 2 ft.) to Core 43 5512 5517' T.D ( 4 ft. r e cov e r e d, top ) were studied. All are of v e ry similar rock namely brown basalt with conspicuous gree n serp e ntinic mate rial. Z e oli tization (red heulandite ? ) is locally conspicuous. In thin section Cor e 43, 5512 -5517' T.D. ( sampl e from bottom o f core), it is se e n to hav e the characteristic t exture of a basalt or diabas e ; the calcic plagioclas e feldspars and augit e remain little altered, but th e larger c1ystals of olivin e have been compl e t e ly r e plac e d by iron oxid e an d iddingsitic mate rial (Figure 8 )

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B ULLETIN N O 55 21 F igure 8. G ul f O i l Compan y B roo ksS c a n l on Blk. 42 No. 1 T ay l o r County Fl o rid a 5512 -5517' ( b ottom o f co r e ) Oli v in e (?) di abas e Th e a r e as a re lim o nitic r e p lacem e nt s o f o livine (?) w hi c h i s a l so r epre s ente d b y o liv e -b rown se r p enti n i c a r eas. Cal c i c p l agioclase a n d a u g i t e a r e fairl y unalte re d. Ordina r y lig ht, X22. T A YLOR C O UN T Y H U MBLE OIL AN D REFIN IN G CO HODG ES 0. 1 625 4 T.D. Completed 1 948 W e ll l oc alit y 5 A pplin (195 1 ) No 8 3 Di abaseb asa lt Applin ( 1 9 5 1 ) s t a t e s th a t this "w e ll t e rmin a t e d in di a b ase ga bbro. U n derl ies ear ly M e s o zo i c cl as ti c roc k s and "6153 -616 5 b asa lti c roc ks; un der li es clas t i c r oc k s o f Triass i c ( ? ) or Jurass i c ( ? ) age 6165 '-62 54 T.D dia b ase ga bbro." Core sam pl e s a r e a v a il ab l e r epre se nti ng som e 96 f e e t o f i g n e o us r oc k from 6153Jr to 624 9 a ll ign eo us ro ck.

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22 BUREAU OF GEOLOGY The uppe r ten or t welve feet of th e vo lcanic rock differs from the eighty-five f ee t of volcanic rock dri ll e d below. The uppe r zone is hi ghly ca l citic, with abundant ca l cite veins, micro-brecc ia and o ther evidence of p oss ibl e contamination by inges ted lim estone. The lower zone is nor mal diabase In d e t ail: Core 111 6 151'-61 recovery sampl e a t 6153W This is a light gray granular volcanic ro c k cut b y a ve rti ca l vein of cal c it e, a quarte r of an in c h wide ( Fig. 9) Gray or green vol ca nic r ock, sampl e at 6155 and anothe r core fragm ent, somewhat coars e r with abundant o ligocl ase -and esine, are a lm os t compl e t e l y chl o ritized and calciti zed manes. (Fig 10 ) 6156' calcitic agglomerat e 6159'-60 gray green vo l canic, with ca l c it e veins Figure 9. Humble Oil and R e fining Co. Hodges No. 1 615:3)2', T ay lor County, F l orida. Basalt with calcite contact (?); so mewhat cal c iti ze d basalt-diabase on l eft, fine graine d calcite on right. Ordinary light, X22.

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BULLETIN NO. 55 23 Core 112 6161'-6 2 r ec overy 1' sa mpl e a t top g r ay green vo lcanic Core 113 616 2'-80' r ec overy 18', sampl e at 6162' top gray green volcanic agglomera te with pyrite and c alcit e v e ins. at 6162' bottom gray volcanic ro c k chl o ritiz e d mafi cs but f e ldspars (oligoclase-ande sine) p erfec tl y fr e sh. Som e fre sh brown biotite Calcite veins. Texture rather coarse, grading into diab ase This rock has b ee n anal yze d (Table s 3 and 3a, No. 5 ) at 6165W gray volcanic tock highly calcare ous probably a volc a nic breccia. (Fig. ll) at 6167' coa rs e diabas e at 6175' coa rs e diabase Figur e 10. Humble Oil and R e fining Co., Hodges No. l 6155 ', T a ylor County, Florida. B asa lt -diabase Th e pyroxe n es, e t c a r e comple t e ly c alcitiz e d but th e plag i o cl ase f e ldspar i s unalte r ed. Ordina ry li ght, X22 .5

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24 BUREAU OF GEOLOGY F igure 11. Humble O il and Refining Co., Hodges No. 1, 6165W, Taylor County, Flor i da. C alciti c ex plosion breccia? The roc k co n sists of a cal c it e matri x w it h r ounded fine graine d ash (?) and chloritic d ebris, as well as coa r se fr es h angu lar p a rticl es of pyroxene, calci c p l agioc l ase highly a lt e r e d biotite and micro-pegmatite. Most of th e lighte r area in the figur e i s cal ci te; s ev e ral rounded ash(?) gra in s a re shown Ordinary light, X17

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BULLETIN NO. 55 25 Figure 12 Humbl e Oil and R e finin g Co., Hodges No. 1 6216' -6219 ', T ay lor County, F l o rida. Coarse fresh norm a l diabase, comple t e ly unaltered. Ordina ry light X17. Core 115 6204 '6219' at 6216' -19 diabase, no c hlorite or ca lcit e in thin section; a per fectly fres h norma l diabase ( Fig. 12 ) This ro c k has been analyzed (Tables 3 and 3a, No. 6) Core 11 6 6229 -6254 at 624 6 -49 diabase, with pyrite along cracks. The two rock a nalyses are in g e n e ral quite similar, as might b e expected, both being of dia base; however, the first shows both more oxidation of iron and c on siderably more water espec i a ll y H20-.

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26 BUREAU OF GEOLOGY JEFFERSON COUNTY COASTAL PETROLEUM CO. E. P. LARSH NO. 1 7913 T.D. Co mpl e ted 1949 W e ll Localit y 6 Applin ( 1951 ) No. 54 Diabas e and r e l a t e d kinds of volcanic rocks ( 7763 -7792' an d 7850'-7890'). Sills or dikes in clasti c rocks of Triassic ( ? ) ag e Applin ( 1951 ) Samp les (c ores and c uttings ) were exa min e d from 7650' to 791 3', in cluding th e two ign e ous intrusives. They are as follows: 7650 -7660 cuttings-mostly r e d sandstone; no ign eous r ock. 7680 -7690 cuttings-red and gray sandstone; no i gneous rock. 7690 -7700 cuttings-mu c h di ab as e with red and gray sandstone. This indicat es a third s ill or dike, b es ides th e two indi ca t e d above. 7720 -7730' cuttings-These are fres h unw ea th e r e d di a base. 7760' -7770 c uttings -diabase 7789'-7791' co r e ( 1 ft. r eco v e r e d ) This is fie sh unwea th e r e d diab ase, sim ilar t o that from 7720 -7730' but somewhat finer grained. Figure 1 3 shows th e typical di abasic micro structur e of this rock. Another sample from this d e pth is c uttings containing much diabase.

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BULLETIN NO. 55 27 D iabas e Figure 13 Coas tal P e trol eum Compa n y, E P. L a r s h No. 1, Jeff e rson County, F lorida, 7789 '7791' This shows th e charac t e risti c t exture ("ophitic") and mine ra logy (e ss e n tiall y augite, ca l c i c plagiocla se and ilm enite). The rock i s practic a ll y un a lt e r e d th e on l y r e placem ent b e ing of olivine (?) b y c hloriti c or ser pentinic material. Cross e d nicols X28.

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28 BUREAU OF GEOLOGY 7791' -7795 core (3 ft. r ecove r ed) Top foot this is a very fin e grained gray micro-po1phyritic b asa lti c rock showing some alteration calcitization and chloritization. It is illustrated in Figure 14. This abrupt change in t exture and composition within a few f ee t indicates that a given magma ma y crysta11ize e ith e r as basalt or diabase in r esponse to very lo cal conditions; and that correlations bas e d on one or the other type of roc k are lik e ly to lead to error. Below this only sedimenta1y rock was found. middle foot. This is a shaly sandstone. bottom foot. This is similar to th e preceding, with l ess quartz. It may be baked shale (Fig. 15). Calcitiz e d basalt Figure 14. Coasta l P e tro l e um Company, E. P Larsh No 1 J effe rson County, Florida, 7791'-7795 Although th e plagioclase f e ldspars are unalte red, th e mafic minerals of th e b asa lt are r eplaced by ca lciti c material. Ordina1y light, X 28.

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BULLETIN NO. 55 29 Baked shale(?) Figure 15. Coastal Petroleum Company, E. P. Larsh No. 1, Jefferson County, Florida, 7791'-7795'. Shows angular quartz particles in very fine grained dark crystalline matrix. Ordinary light, X 28. 7909'-7911 (IJf recovery) This is a whitish sandstone, almost wholly quartz, with strong evidence of recrystallization almost all the quartz grains show peripheral secondary growth, and clay is recrystallized to seri cite. There is also green tourmaline, in minute grains, also probably authigenic (Fig. 16 a, b). 7911'-791 3' (IJf ft. recovery) Sample from bottom 1 ft 10 in. of core. Two different specimens: One is hard rather coarse sandstone, light col ored; the m atrix of the quartz grains however is well recrystallized into pale green chlorite. The other specimen is rounded pebbles (I em. across) of red very fine grained shale, possibly volcanic ash.

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A" "< ... 0 5 mm Sandstone Figures 16 a, b. Coastal P e trol eum Company, E. P. Larsh No. l J e ff e rson County, F lorida, 7909' -79ll' This shows f eature s which may p erhaps b e r e l a t e d to thermal m e t amorphism. M a n y of the quartz grains show second..:.:....:oo;... ____ .. d etrital grains b :ing n e d by dark rims ,in t!1e illus.trations, with w 0

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BULLETIN NO. 55 31 In summary, a series of sandstones and shales was intruded by diabase or related roc k at (or not far above) 7690', 7720'-7730' and again at 7789'-91', 7791' -95' Below this to 7913' T.D. there are indications of volcanic activity, but no specimens of actual volcanic ro ck. FRANKLIN COUNTY CALIFORNIA CO. AND COASTAL PETROLEUM CO., NO. 2 Well locality 7 State Lease 224a. Latitude 29'03" N Longitude 84'51" W South Shoal area about 13 miles offshore from Carrabelle, Florida T.D. 10566' (dr ille r), 10507' (electric log). Completed 1961. This well drilled into 10 feet of diabase at 10460 ft (Data from P. L. Applin written communication 1967). Spec imens are available as follows: 1031 8-19 10324-25 1032 0-21 <> 10325-26 10 321-22 10326-27 103 22-23 10327-28 1032 3-24 <> These are all pinkish quartzitic sandstone (cored), well-indurated some with white clayey specks. Figure 17 illustrates 10325'-10326 The Sand stone fro m contains much calcite. <> 10460 -70 10510-20 10 470-80 "10520-30 (Figure 18, basalt-diabase) Figure19 baked shale 10480 -90 10530-40 1049 0-10500 10540-50 1 0500 -10 10550-60 These all contain diabase fragments, admixed with sandstone. "Thin section s JACKSON COUNTY HUMBLE OIL AND REFINING COMPANY C. W. TINDEL NO. 1 T.D. 9245' Completed 1949 Well locality 8 Applin (1951) No. 53 Applin (1951) refers to this as follows: "8890' 8932' Porphyritic hornblende basalt. A small intrusive or flow in Paleozoi c rocks," with a thickness of 42 feet. However, the overlying sand 888 1'-88 91' (top 5)f feet) is a fine grained reddish sandstone show mg. structures interpreted as being due to contact metamorphism, indicatmg an intrusion rather than a surface flow. A specimen from the bottom 6)f of this core is hard fresh fine grained basalt, showing marked calcitizatio n

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32 BUREAU OF GEOLOGY Six sp e cim e ns of th e core from this w ell are: Core 100 8521'-8526 ( sic ) fine grain e d r e d siltston e Core 120 8737'-8742' fine grain e d gray siltston e Both of the s e are similar to the siltston e sp e cim e ns b e low th e ign e ous ro ck. Core 130 8881 8891 (top feet ) fine graine d light r e ddish brown siltstone. It shows disturbance and inte rna l dislo cation ( fig. 20), and i s interpre t e d as a mildl y contac t-m etamorphose d siltston e ov e rl y in g th e intrusiv e rock r epre s ente d by th e following sp e cim e n C o r e 130 8881' 8891 (bottom 1 ft. of ft r ec ov e ry ) i s h ard fr e sh fine graine d basalt, strongly cal citi z ed. Abundant calcic pl a giocl a s e is fairl y fre sh as is also minor brown hornblende; but large are as in th e .... I -'1' \ l .... "i"'/ "'- l '4' .Qo. Fi gure 17. Californi a Co. and Coast a l P e trol eum Co. No. 2, Fra nklin County, Fl o rid a 103 25 10326 Sandston e with rounde d quartz g r a in s sho wing s econda ry g rowth W ell crystalliz e d ca lcit e and di c kit e (?) aggregate s o ccur inte rstitially. Ordi n a ry light X36.

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BULLET! 0 55 33 thin stc:tion, formerly pyroxene or olivin a r e now vagu e browni h ag gregates of calcite, chlorite, and clay y material. Sm a ll brownish e uh edra l opaque ore grains with somewhat large mass e s of p y rit a r fairly abundant ; and quartz filled amygdul es a r pre e nt. Figures 21a, b illu s trate t his rock. Core 136 8987'-8997' is fine grained r ed t a ndston Core 141 9232'-92.37' is fine g r ain d g ra y calcareous siltston uni form in thin se tion unlike the si ltston e ove rl ying th e basa lt. Core 142 9237'-9242 is similar. Figure 18. 0 5 mm I California Co a11d t 1 p 1 1 F k 10520 o as a et10 e um o. o. 2, r an lm County Flonda -1053 0'. a lcitized B a a lt. The b asa l t consists almost wholly of fresh plagi oclase obscure matrix largel y ca l c it ; w ith so m e ilm e nit e. Ordin a ry light

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34 BUREAU OF GEOLOGY In summary, these four sampl e s indicate that a 42 foot basaltic sill i ntrude d a siltston e s e ries in which the w e ll bottomed 313 feet below the ign e ous ro c k at 9245 T.D. The siltstone conta ins plant fragments iden tified by S. H. Mamay as Psilophyton s.l. indicativ e of an Early or Mi ddle D evonian age ( B erdan, writte n communication, May, 1970 ) 0 5 mm L-......1 Figure 19. California Co. and Coastal Petroleum Co. No. 2 Franklin County, Florida 10520' 105.30'. Bak e d sha le. The dark areas are calc areous, and appea r t o represent foraminife ra. The gray matrix i s a mud-stone w ith minute angular quartz particles. Ordinary light Xl7.

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BULLETIN NO. 55 35 Fi gure 20. Humbl e Oi l and R efining Company C. W. Tinde l No. 1 J a c k s on Coun t y F lorid a, 888 1 '8 8 91 ( t o p Fine g r aine d s ilt s t o n e overlying b asa lt and s howin g flo wage and oth e r m e ta m o rph ic e ff ec ts. Ordina r y light, Xl3

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Amygdaloidal (quartz) Ba sa lt Figures 21 a b. Humble Oil and Refining Company C. W Tindel No.1, J ac kson County, Florida, 8881 -8891 Quartz amygdule (bottom) surrounded by highly calciti ze d zone in basa lt. Anotber large calcitized area, with very minor quartz, i s seen uppe r l e ft. The slightly darker small e r areas are calcitized pyroxe n es. Ordinary light and crossed nicols, X28.

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BULLETIN NO. 55 37 WALTON COUNTY PAN AMERICAN PETROLEUM CO. J. R. SEALY NO. 1 T. D. 11948 FT. Sec. 9 TIS R18W Cente r SE J4. Completed 1950. W e ll lo cality No.9. Top ofvoTcanic rocks 11910 ft. Fragments (cuttings) 11935'-11940 heav ily altered porphyritic rhyolite. Data from P. L. Applin (written communication 196 7) Specime ns were examin e d as follows: 11920'-11930' -Sandstone, arkose and felsite 11930 -11935' -Sandstone, arkose and felsite 11935 '11940 Rhyolit e porphyry ash w ith obscure shard structure s in trix of plagioclase, phenoc1ysts. Also much sandstone, e tc. Figures 22, 23. Figure 22. Pan American P e trol eum S ea ley No. 1 11935'-40'; Walton County, Flor ida. Seri citized rhyolite porphyry or as h with feldspar phe nocrysts Ordinary light X 3 5.

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38 BUREAU OF GEOLOGY Figure 23. Pan Ame rican P e trol e um Seal ey No.1, ll935'-40', Walton County, Florida. S eric iti ze d rhy o lit e or ash. Ordina ry light X35. 11940 -11945 Rh yo lit e porphyry ash with obscme shard structures in matrix of plagioclas e, phe nocrysts. Also much sands t one, e tc. 11945 -ll950' Rhyolit e porphyry a h with obscur e s hard structur e s in m a trix of plagioclase, phe nocrysts. Also much sandstone, e tc. HUMBLE OIL A D REFINING COMPANY J. W. CAMPBELL NO.1 FLAGLER CO., FLORIDA Compl e ted 19 47 T. D 4632 W e ll lo ca lit y 10. Applin ( 1951 ) o. 19. Mixed tuff d e rived from an i gneous comp l ex. Ori gin sedimentary or ex plosiv e i g n eous ac tion." F F. Grout. P. L. Applin ( 1951) Applin not es that th e ign eous rock was e n countere d at 4588 an d drillin g continue d in such to 4632 T. D.

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BULLETIN NO. 55 39 The sam pl es avai lable have t wo r eco rd ed d epths, o n e of th e m "co rr ec t e d 12 l ess th an th e o th er. The d epths cite d a bo v a r e "correc t e d. Cores for th e interv a l 456 0 to 4575' we r e s tudied a s follows : Core 67 456 0 -70 r ecove r y 8)4 f ee t top middle and bottom all fri a bl e white sa ndstone. Co r e 6 8 457 0 -75 t o p fr iabl e white sa ndston e; middle buff to r e d friab l e sandstone; bottom hard indura t e d r e d sandston The top o f th e ign eo u s r oc k in this we ll i s a t 4588 Possib l y the c hange noted in th e l as t co r e 68 may be ca used by th e ign eou rock found 1 3 f ee t low e r down ; but this inte rv a l i s not r epresente d by any sample Co r es beginning at 4 601 in th e ign eo u s s c tion w e r e studie d as f o llows: Core 69 (top) 461 3'1 8' r ecove r y 3ft. correc t e d measurement 4 601 -06 ( b ottom) 461 3'-18' r ec ov e 1 y 3 ft. corrected m easure m ent 4601'-06' Both samples a r e rath e r fin e grained volcanic rock th e fir s t r eddis h th e second d a rk er. Whitish clayey m a t e ri a l coats the surfa ces and v e in s th e co r e pieces. Core 7 0 ( t op) 461 8'-4 62 4' recove r y 3' correct d measure m ent 4 606 -12 (middl e) (about 6 abo v e bottom) These three samples a r e s imilar t o prece ding. (bottom 6 a pproxim a t e l y) This is d a rk g r ay fin e g rain e d rock showing ( in 1 in c h frag m e nts ) no agg lom e r a t e structure o r cl ay veining or coa tin gs. Core 71 4624' 4624%' r ecove ry 6 cor rected m easure m ent 4612 4612%' Thi s is a fin e g rained dark gray r ock. Core 72 4 624g4'-4626 correc ted mea ure m ent 4612%'-4614 This s p ec im e n i s a fin e g r a ined g r ay rock w ith whi t e cla yey patches In thin sec ti o n s h ows a h e t e ro geneo u s agglomerat e of heavil y al t e r e d basalti c d e bris and qua1tz it e pa1ticles, sea m e d with veinl e ts of cal ci t e and, possibly, pum p e ll yite. Figur 24 ill ustra t es this ro ck. With ou t the thi n sec ti on, the ro c k could b e t e rm e d fin e g r a in e d b a s a lt but thi s ro ck, and pre sumably the others a bov e it, are a lmost cer t ai nl y alte r e d volcani c ash. Core 73 T o r ecove r y Core 74 4627'-29' r ecove r y 6 correc t e d m easure m ent 4 615 4617' o thin sec t ion is av ailab le, but ca reful in spectio n under a binocul a r mi c ro sco p e s u gges t s tha t it is lik e the preceding. Core 75 4 627'-29 r ecove r y 1' correc t e d m easuremen t 461 5' -17' Simil ard e ns e dark gray fin e grained. Core 76 463 0'3 1' r ecove ry 1 co rr ec t e d m easure m ent 4618 -19 Simil a r Core 77 463 1 32' r ecove r y 1 correcte d m easure m ent 4619 -20 Simil a r

PAGE 40

40 BUREAU OF GEOLOGY Figure 24. Humble Oil and Refining Company, J. W. Campbell No. l, Flagler County, Florida. -4626'. This is a volcanic agglomerate, perhaps hydrothermally altered ash. Calcite hornblende veinlets cut the rock. The two light colored areas at the left edge are aggregates of acicular pale green hornblende; the clear areas at the right are granular quartz. The dark areas are mostly aggregates of extremel y fine black opaque material; a few are magnetiteilmenite. Under high magnification, yellow epidote (?) and brown sphene in irregular grains are seen. Ordinary light, X22 Core 78 4632'<33' recovery 1' corrected measurement 4620'-21' Similar Core 79 4633'-34' recovery 6" corrected measurement 4621'-22' Similar Core 80 4634'-35' recovery 10" corrected measurement 4622'-23' Similar Core 81 4635'-36' recovery 1' corrected measurement 4623'-24' Similar

PAGE 41

BULLETIN NO. 55 41 Core 82 4636'-37' recovery 1' corrected measurement 4624'-25' Similar. Some of the preceding have white, greenish, or in this core, reddish veinlets. Some veinlets are mostly calcite; this one is a zeolite. Core 83 4637'-38' recovery 8" corrected measurement 4625'-26' Similar Core 84 4638'-39' recove:? 1' corrected measurement 4626 -27' Similar; fine grained dark gray, with greenish veinlets one or two millimeters wide. In thin section, an aggregate of rhyolitic and other igneous fragments, including altered feldspars and pale green hornblende. Some of the rhyolite fragments have micro-pegmatitic structure. (Fig. 25) Core 85 4639'-40' recovery l' corrected measurement 4627'-28' Similar Figure 25. Humble Oil and Refining Company, J. W. Campbell No. l, Flagler County, Florida. 46.38' -46.39'. Volcanic agglomerate-ash. The clear areas are quartz; the finely dotted area, lower l eft, devitrified glass. Coarse feldspar grains, and greenish pyroxene(?), both heavily altered, can be seen. Ordinary light, X22

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42 BUREAU OF GEOLOGY Core 8 6 464 0' -41' r ec overy 1 correc ted m easure m ent 4628 -29 Similar Core 87 464 1'-42' recovery l' corrected m easurement 4629 '-3 0 Similar Core 88 4642'-43' r eco very 9 corrected measure m e n t 4630' 31' Similar with fin e sa lmon colored zeolite in v e inl e ts. Core 89 4643'-4 4 r ecove r y corrected m easure m ent 4 631'32 T.D. Similar. In thin sec tion an agg lom erate of shattered qua rtz g rains b a saltic fr ag m e nts alt e r e d f e ldsp a rs and mafic min e rals and bl ac k opaque dust and iron oxide (Figs. 26a b ) Bas s ( 1969 ) gives p etrographic date for a sam pl e d es i g n a t e d as "4 641-4642 ft. A sample of Core 87, from this d epth, 1 ft r ecove ry is fine grained dark gray tuff."

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Figures 26a. b. Humble Oil and Refining Company, J. W. Campbell No. l, Flagler County, Florida. 4643' -4644'. Volcanic agglomerate ash. The clear areas are mostly quartz, others are feldspathic. Large Carlsbad -twinned feldspars are seen in thin section, as large or even larger than the quartz aggregates, suggesting that the latter too are of volcanic origin (phenocrysts) and not fragments of engulfed sedimentary quartzite or sandstone. Ordinary light and crossed nicols, X22. CJI CJI

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44 BUREAU OF GEOLOGY PUTNAM COUNTY SUN OIL COMPANY H E. WESTBURY ET AL 3892 T.D Comple t e d 1 949. Well loc a lity 11 Applin ( 1951 ) No. 25 "Vo l canic ash and tuff. Applin ( 1 951 ) B ass ( 1969) has d esc rib e d co r e s p ec im e ns from this w el.l, as note d b e lo w. This w e ll drill e d into 19 f ee t of vol ca ni c ash Samp les are ava ilabl e from 38 72 to 3892' T. D Cor e 190 387 2 -74' r e cove r y 7" mid 3 inc h e s (sp ec im e n ) Hard r e ddi s h cl ayey rock with rounde d qua1 t z gra ins. The cla y swells an d disint eg r a t e s in wate r s ug ges tin g b ento niti c volc anic as h bottom 3 inc hes: rath e r friab l e white cl ayey ro c k no quartz grains. B ass ( 1969 ) d esc rib e s the m a t e ri a l from 38 71.5 t o 3874 ft. as p e rh a ps a s ilt y mudston e or a thorou g hl y weathered tuff; from 387 6 to 3878 ft as microcr ys t a llin e w e lded tuff or pumice Cor e 193 3878 -3879 r ec overy 12 h ard very fine g rain e d r eddis h r oc k B ass ( 1969 ) describes this ro c k as l aminat e d tu ff Core 194 38 79'-3881 r ec ov ery 20 lik e th e preceding wi th e llipsoidal bl eached areas a c entime t e r or two across. In thin section it is see n to b e vo l ca nic ash ( Fi gure 27). It contains a marin e (?) foss il. This samp l e h as b ee n a n a l ysed ( T a bl e 3 ) Core 19 5 3881' 3883 r ec ov e ry 24 t op 1 inch: simila r to pre ceding.

PAGE 45

BULLETIN NO. 55 45 Figure 27. Sun Oil Company, H E Westbury e t a!. No. 1. Putna m County, Florida. :3879' -:3881'. w ith fossil upper right. The othe r structures seem to b e intense l y altere d fine-gr a in e d vokanic fra g m e nts. The dark a reas are irons t aine d. Ordinary light X22Jf.

PAGE 46

46 BUREAU OF GEOLOGY Bass ( 1969 ) describes this co r e as lithic-c 1yst a l tuff w ith r e li c t shard structure bottom 1 inc h: s imilar to preceding, grading from r eddish t o white. Cor e 196 3883 3885' recov e 1 y 12 Similar t o preceding. In thin section the reddish areas in the specim e n a r e seen to b e colore d b y r e d dish h ematitic (?) dust, whereas the white areas a re p a l e g reen, and c hloriti c A few highly a lt e red fiagments o{ coarse r volc a ni c rock are im b edde d in an extre m e l y fine graine d clayey)matrix. Core 197 3885 -3887' r ecovery 17" This is more grayis h in co l o r but other wise lik e the preceding. In thin se ction it shows shard structures B ass ( 1951 ) giv es fmther d e t ai ls. (Fi g 28 ) Pyroc: l astic: Figure 28. Sun Oil Compa n y H E. Westbury e t al. No. l. Putnam County Flo rid a. 3885 -.3887". Finegrained roc:k with sc:atte red sodic: plagiodase f e ldspar c:rysta l s ( w hi t e). The whit e streak s are minut e fissures fill e d with quartz. Ordinary li ght X l 7 J t

PAGE 47

BULLETIN NO. 55 47 Core 198 3887'-3889' r ecovery 12 This is bluish gray ash, with numerous reddish grains a millimeter or two across. They a r e usua lly feld spar, either single large crystals, or granular aggregates, or highly feld spathic rhyolite. Some fragm ents consist of aggregates of almost color l ess spherulitic chlorite Bass (1969) describe s this co r e : Clastic vague ly laminate d welded tuff. Core 199 3889 -3890 r ecovery 10 Similar to preceding with fairly large (severa l millimeters or more) fragments of well crystallized rhyolite and singl e unaltered plagioclas e feldspars; also qua1tz grains. Bass (1969) describe s this core as clastic volcanic conglomerate or ag glomerate. (Fig. 29) Figure 29 Sun Oil Company, H. E Westbury e t al. o. l Putnam County, Florida. 3887'-3891' Shows h e t eroge n eo us character. The l a rg e fragment (low e r l e ft) sug gests e ither a shattere d quartz crystal or a line g rain e d sandstone. Ordinary light

PAGE 48

48 BUREAU OF GEOLOGY Co r e 200 38 90 389 2 T D. r e co v e r y 24" Simil a r to preceding ( Fi g 3 0 ) B ass ( 1 9 6 9 ) d escrib e s t h i s as s imilar t o hi s pre c e ding sam ple, wi th l a min a t e d w e ld e d tuff Fi gure :30 Sun Oil Compa ny, H. E W estbury e t a!. N o 1 Putnam County, Florida :3890 -.3892' T.D. Sh ow s variegate d structure (fine and c.;o a r se ) The c.;o a r se i s l a rg e l y q u a rtz. Ordinary light Xl7)2

PAGE 49

BULLETIN NO. 55 MARION COUNTY, FLORIDA SUN OIL COMPANY HENRY N. CAMP NO.1 T.D. 4637' 49 Comple t e d 1947 Well locality 12 Applin (1951) No. 23 "Vocanic agglom e r a t e or tuff of rhyolitic composition. Mix e d tuff d e riv e d from an igneous complex.' F. 0. Grout. Applin ( 1951 ) Applin 22 f ee t of volcanic ro c k beginning a t 4615 ft. Bass ( 1969) describ es specim ens from this w e ll, as note d b e low. H e describes cuttings from 4500 to 4610 ft. and core from 4574 to 4584 ft. as coarse grained conglomeratic sandstone l oose ly cemented b y chlorite; about 1 p ercent or l ess of the sandstone is rhyolitic ash. Only two samples a r e available: Core 22 4574 -4584' (two differ ent rock types) a ) fin e grained ash? b ) coarse graine d agglomerate ()r arkose fragments a milim e ter or two in s i ze. (Figure 3 1 ) The r e is such a diff e r ence b etween these two specimens that it is pos sibl e th a t the coarse grained rock ( b ) is mislabe l e d. It shows d e finite indications of metamorphism by igneo us contact, and contains fr a gments of rhy oliti c rock (fig. 28 ) with co a rs e quartz and f eldspar. The matrix has bee n r ec r ys talliz e d to micaceous aggregates. Core 23 (bottom) 4623' Again the re are two somewhat contrasting specim e ns one a coarse volCani c agglomerate, th e other rhyolitic welded tuff or rhyolite, with large quartzes and sodic f e ldspars. Both however, could well represent variant phases of a singl e ash fall shifting winds and variations in explosive activity in the crater causing marke d c h a nges in mate ri a l d eposite d at a n y one point. Ross ( 1958 ) cite d by Bass (1969) found 4618 to 4653 ft. to b e welded tuff. B ass also found cuttings from 4610 to 4630 ft. to be rhyolitic welded tuff. Dorothy Carroll ( 1963 p All Fig. 6 ) found h e r heavy min eral assemblage A in quartzite at the Camp well at a d epth of 43764383 f ee t below sea level (core 121 ) This assemblage also occurs in quartzite in Humble Oil and R e fining Co. C. E. Robinson No. 1 (Levy County) which is considered to be Early Ordovician in age on the basis of fossils. The quartzit e in co r e 121 from the camp well is also probably Early Ordovician ( Berdan, 1970, written communication). Three other wells h a v e been drill e d in Marion County in none of which igneous rock was r eported. They a r e: JS. Cosden, W L. L a wson No. 1 43 34 T.D. Ocala Oil Corp., Cl a rk-Ray-Johnson No 1 (York) 6180 T.D. Sun Oil Co., H. T. Parker No. 1 3845' T.D. All a reieported to h ave bottome d in quartzitic sandstone (P. L. Applin,

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Figure 31. Sun Oil Company, Henry N. Camp No. 1, 4574' -4584', Marion County, Florida. Coarse agglomerate or Shows large quartz grains with micro -brecciated structure. The dark grain lower right is rhyolite, with typical rounded quat-tz phenocryst. Ordinary light Xl4. c.n 0

PAGE 51

BULLETIN NO. 55 51 1951); of probable Early Ordovician age ( B erdan, 1970 written co mmunication) The Sun Henry N. Camp N. 1 with volcanics at 4623 is onl y about 20 mil e s east of Oca l a Oil Corp. Clark-Ray-Johnson No. 1 ( York ) which repmte dly found no igneous rock down to 6180' T.D. LEVY COUNTY FLORIDA HUMBLE OIL AND REFINING CO. C. E. ROBINSON NO. 1 T.D. 4609' Compl e t e d 19 49 W e ll locality 13 Applin ( 1951 ) No. 60 "43 17' -4344 decomposed igneous rock; unde rlies low e r Cretaceous sandstone. 4344 4377' basalt; overlies a lt ered black sha l e of Pal eozo ic age. (Applin 1951) Three very small samples are availabl e The r e is som e question as to exactly whic h cores th ey represe nt. The depths, however, are believ e d to be correct. Core 59 (?) 4331'-4336 This is a rather coarse granular aggregate, mostly greenish, but also brownish grains. In thin section th e rock is seen to consist of a chloriteclay(? ) matrix with abundant carbonate ( dolomit e?) areas, both with rathe r obscure radial. crystalli za tion. Coarse opaque grains, some ilm e nit e other l e ucox e n e and limonit e a re nume rous. Quartz is almost absent. (Figure 32 )

PAGE 52

Calcitized basalt Figure 32. Humble Oil and R e fining Company, C. E. R ob in son N o l L evy County, Florida, 4331' 4336'. Radially cry s t a llized masses of dolomite (?) i n a ch loriti zed matrix. F e ldsp ars are rep laced by obscure ly radial day (?) material, mafic mineral s by pale green chlorite. Ordinary li g ht, X22%. I \

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, BULLETIN NO. 55 53 Core 59 (or 60?) 4344' -4356 near top "overlain by 8 ft of red clay" Applin. This is a fairly hard light gray rock. In thin section, it 1s seen to be a diabasic rock, with fresh plagioclase and calcitized augite. It shows to a relatively minor degree the same type of hydrothermal alteration seen in the preceding specimens (Fig. 33). Pyrite unaltered to limonite, and ilmenite unaltered to leucoxene, are present. The "red clay" of Applin may represent an intensely altered part of the igneous body. Core 59(?) 4358'-4359' This is augite diabase, showing none of the alteration of the preceding samples (Fig. 34). Calcitized basalt or diabase Figure 33. Humble Oil and Refining Company, C. E. Robinson No. l, Levy County, Florida, 4344' -4356' (near top). Although the plagioclase is unaltered, nearly all the augite is replaced by calcite The black areas are mostly fresh magnetite-ilmenite with a little pyrite Minor quartz is present and green chlorite. Ordinary light, X22.5.

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Almost unaltered diabase Figure :34. \Humble Oil and Refining Company, C. E. Robinson No. l, Levy County, Florida, 4:358' 4:359'. Ordinary light,

PAGE 55

BULLETIN NO. 55 55 Although the 28 feet of igneous s e ction appears to show a progressiv e degree of alteration from top to bottom, this may not be the result of weathe ring but of hydrothe rmal alt e ration. "The diabase in the Robinson w e ll overli e s 232 fee t of quartizitic sand stone with minor a mounts of shale, which i s dated a s Early Orodivi c i a n on the basis of linguloid brachiopods (Berdan and Bridge 1951 p 70 ) VOLUSIA COUNTY GRACE DRILLING CO., RETAIL LUMBER CO. NO.1 T.D. 5424' Compl e t e d 1949 W e ll lo c alit y 1 4 Applin ( 1951 ) No. 26 "Rhyolitic(?) volcanic rock Applin (1951). Applin ( 1951 ) r epmts that this w e ll drill e d 21 fee t in volc a nic rock. A specimen of cuttings from 5424Jf' T.D. show arhyolitic ro c k alm o st wholly plagioclas e feldsp a r (near oligoclas e -andesin e) with a littl e qua rtz and littl e or no m afic min e rals. It is illustrat e d in Figure 35. This w e ll is l ess than 20 miles NNW of the Sun Co. Pow e ll Land Co. No. 1 which at a d epth of 5922 drill e d rock r epmte d a s over 400 m .y. age.

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.,.,. / 56 BUREAU OF GEOLOGY Rhyolite Figure 35. Grace Drilling Co., Retail Lumber Co. No. l Volusia County, Florida. T.D. The volcanic rock consists a lmost entirely of moderately sadie plagioclase in interlocking aggregates of lath shaped crystals, some porphyritic and euhedral, and very minor int ers titial quartz. The feldspar is slightly sericiti zed, with reddish dust giv ing it a brownish tint in sect ion. Som e black ore grains, and a littl e calcite, are present The l arge rectangular crystal is plagioclase feldspar. Ordinary light, X27.

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BULLETIN NO. 55 VOLUSIA COUNTY SUN OIL CO. POWELL LAND CO. NO.1 5958 ft. T.D. 57 Comple t e d 1946 Well locality 15 Applin (1951) No 7 Hornblende diorite (Applin 1951 ) This is one of the three wells in eas t central Florida that Applin ( 1951 ) considere d to have reach e d the "metamorphic bas e m ent," the others being Lake County, J. Ray Arnold No. 1 and Osc eo l a County, N. Ra y Carroll No. 1. Later the St. Lucie County, Amerada Cowles Magazine No. 2 and Hillsborough County, Humble T. S. Jamison No. 1 drilled into similar "metamorphic" ro ck. Bass ( 1969 ) has studied specime ns from this well in great detail as noted below. Nin e teen specimens from this w e ll, representing depths from 5903' to 5958' T.D. have been studied. "According to D. J. Munroe (Sun Co. Geologist") this w e ll encountered a weathered zo n e? beginning at 5910 ... memo to W a tson Monroe from Applin, April 3, 1947. The follow ing are notes on the samples studied: Sid e Wall Core 5903 White Sandstone Sid e Wall Core 5906 White sandstone Cuttings 5910'-20' White sandstone, e tc. Cuttings 5920'-30 White sandstone, etc. Core 178 5922'-25' 3 recovery, top of co r e Soft coarse volcanic rock now clay but with origin a l texture. (Figure 36) Core 178 5922' -25 has been interpre t e d as possibly a weathered zone, and indee d there is a striKing contrast between the white sandstone and the unde rlying volcani cs, with no indication tha t the sandstone has been metamorphosed by the volcanics. In other words, the sandstone deposition is subsequent to the consolidation of the ign eo us rock. In thin section, the rock is seen in Figure 36. Rathe r than weathering, intens e hydrothermal alteration is possibl e The rock is illustrate d in Figure 36. Minute angular fragm ents of fairly fresh alkalic feldspar are seen sparingly, surrounded by clay. Vivid green, strongly pleochroic (yellowish to bright green) platy fibrous chlorite-like mineral may b e ferrostilpnomelane. Small apatite crys tals are prese nt. Bas s ( 1969 ) class es the rock from 5922-25 ft. as "either transported material or weathered b asement rock that was mixed with overlying material during mass mov e ment.'' Cuttings 5930' -40' Cuttings 5940' -50' Cuttings 5950' "Decease d. White sandstone, volcanic debris Volcanic debris, white sandstone, e tc. Volcanic debris, white sandstone, etc.

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"Weathered" ign eous rock Figure 3 6. Su n Oil Co., Powe ll Land Co. No 1 5922 -5925', Vol usi a County, Florida. The light color e d areas are cryptocrystalline clayey material; the dark, chloritic aggregates; and the black, limonitic mate rial. Shattere d quartz grains (white) suggest e xplosiv e h ydrothermal ac tivit y. The limoniti c materia l may have r e placed f erromagnes ian silicates; a few blac k ore g r a ins are unalterecl. Ordinary li ght, Xl5.5. Cll 00

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BULLETIN NO. 55 MARION COUNTY, FLORIDA SUN OIL COMPANY HENRY N. CAMP NO.1 T.D. 4637' 49 Completed 1947 W e ll loc a lity 12 Applin ( 1951 ) No. 23 "Voca nic agglomerate or tuff of rhyolitic composition. 'Mix e d tuff de riv e d from an igneo us compl ex.' F. 0 Grout. Applin ( 1951 ) Applin gives 22 f ee t of volcanic rock beginning a t 4615 ft Bass ( 1969 ) describes specim ens from this w e ll as noted below. He d esc ribes cuttings from 4500 to 4610 ft. and core from 4574 to 4584 ft. as coarse grained conglomeratic sandstone loos e ly cemented by chlorite; about 1 percent or l ess of the sandstone is rhyolitic ash Only two samples are avail able: Core 22 4574 -4584' (two diff erent rock types) a) fine grained as h? b) coarse grained agglomerate or arkose fragments a milim e t e r or two in size. (Fi gure 31) The re is such a diff erence between these two specimens th a t it is possible that the coarse grained rock ( b ) is mislabe l ed. It shows d e finite indications of metamorphism by ign eo us contact, and contains fragments of rhyolitic rock (fig. 28) with coarse quartz and feldspar. The matrix has been recrystalliz e d to micaceous aggregates. Core 23 (bottom) 4623' Again there are two somewhat contrasting s p ecimens, one a coa rse volcanic agglomerate, the other rhyolitic welded tuff or rhyolite, with large quart zes and sadie f e ldspars. Both however, could well r epresent variant phases of a singl e ash fall, shifting winds and variations in explosive activity in the crater causing marke d changes in mate rial deposite d a t any one point. Ross ( 1958 ) cited by Bass ( 1969 ) found 4618 to 4653 ft. to b e welded tuff. Bass also found cuttings from 46 10 to 4630 ft. to be rhyolitic welded tuff. Dorothy Carroll ( 1963, p. All, Fig. 6) found h e r heavy mineral assem blage A in quartzite at the Camp well at a d epth of 4376-4383 feet below sea level (core 121 ) This assemblage a lso occurs in quartzite in Humble Oil and Refining Co. C. E. Robinso n No. 1 ( L evy County) which is considered to be E a rly Ordovician in age on the basis of fossils The quartz it e in core 121 from the camp well is a lso probably Early Ordovician (Ber dan, 1970, writte n communication). Three other w e lls have been drilled in Marion County in none of which igne ous rock was reported. They are: J.S. Cosden, W L. Lawson No. 1 4334 T.D. Ocala Oil Corp. C lark-Ra y-Johnson No.1 ( York ) 6180' T.D. Sun Oil Co., H T. Parker No. 1 3845' T.D. All are reported to have bottome d in quartzitic sandstone (P. L. Applin,

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BUREAU OF GEOLOGY Figure 37. Sun Oil Co., Powell Land Co. No. 1, 5954' -5955', Volusia County, Florida. The small smooth rectangular area bottom center is green chlorite; another area is at the center. The clear areas are quartz, the darker hornblende; the gray mostly feldspar. Ordinary light, X27. \

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BULLETIN NO. 55 61 Diorit e with epidote Figure 38. Sun Oil Co., Pow ell Land Co. No. 1 5954 5955 Vol usi a County, F l o rida. Shows ep idote v e in l e t (low e r l eft). Ordinary li ght, X20.5

PAGE 62

r f ""'' .. Hornfels Figures 39a, b. Sun Oil Co., Powell Land Co. No. 1 5955' -5956', Volu s ia County, Florida. Shows brown biotite and pale gree n hornbl ende with quartz-sodic plagiocla se Concentrations of eithe r or both together, the t erromagne sian mine r als a r e see n; h e r e th e quartz-felds p a r is fine r grain e d (low e r l e ft ) All gra in s are anhedra l and th e t exture is granitic. Ordina ry light and c rossed.ni c ols, X27

PAGE 63

Hornfels Figure 40. Sun Oil Co., Powell Land Co. No. 1, 5957Jr -5958', Vol usia County, Florida. Rock sim ilar to preceding figures, showing mafic concentration. Orindary light Xl6.

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64 BUREAU OF GEOLOGY Rock from core 180 5953-5954 ft. has been date d by H. Thomas, R. Marvin, P. Elmore, and H. Smith of the U. S. Geological Survey ( Meuhlburge r W R., et al., 1966 ) as 480" m.y. (by K-Ar). Bass ( 1969 ) found for the rock from 5951 to 5958 ft. 5951'-5955' Hornblende in diorite 5951 -5955 Plagioclase in diorite 5955.5'-5958' Biotit e in hornfels 5955.5' -5958' J6ornblende in hornfe ls 5955.5 -5958' Biotite in hornfels Bass offers various explanations of these discr epancies 459 m.y. (K-A1) 342 m .y. ( K-Ar ) 524 m.y. (K-Ar) 393 m.y ( K-Ar ) 634 m.y. (Rb-Sr) To summarize the se data, it appears that these dates aggree in indicating an age for the rock in excess of 342 m.y., th a t is, an age older than Miss issippian. LAKE COUNTY, FLORIDA LAKE COUNTY OIL DEVELOPMENT COMPANYGFFLORIDA SOUTH LAKE NO.2, (J. R. Arnold No. 1) T.D. 6129' Complete d 1937 Well locality 16 Applin (1951) No. 5 "Granite at 6103 Applin ( 1951 ) In a lette r to Watson Monroe, Applin ( Nov. 4, 1937 ) wrote .... in 1937 a sample w as submitted to W. H. Tomlinson at Swarthmore, Pa., who reporte d it to be alaskite a granitoid rock having 50 percent ortho clas e, 40 percent quartz, 10 p ercent oligoclase, and 2 p ercent biotite.' Tomlinson's opinion expressed at that time was to the effect that the alas kit e was probably a dik e .... Late r, a few tiny fragments of this rock were insp ected by Charles Milton who agree d with Tomlinson' s findings as to A thin section obtained from Mr. A. P. Bennison, of the Sinclair Oil and R e fining Company labele d "Oil Dev. Co. of Fla. South Lake Well Core 6107'-28 Granite 17-24S-25E made by Tomlinson, is definitely the sam e rock. It shows no trace of weathe ring (Figures 41a, b). It may b e note d that this type of rock is quite similar to "granitic ro c k encountered by drilling in Perc e County, Georgia. This is one of the most controversial of the Florida wells. Schuchert ( 1943 ) mentions a miliolid lim e ston e, referred to middle Cretaceous at 5383'; anhydrite between 5383' and 6050'; followed by red clays, gravels sands and then granite. The owner of the well denied the presence of granite. Campbell (1939) obs e rves tha t "granite or not, the miliolid lim e ston es at 5383' some beds of anhydrite, and the red sands and gravels "The original report to Charles Milton, date d Nov. l, 1962 noted that "this age may b e lo w by 20 percent or more due to the variable argon retentivity of the potassiumb ear ing minerals of this sample."

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0.5 mm L.__j "Granite" Figures 41a, b. Thin section plane polarized light and crossed nicols x 16. Oil Development Company of Florida South Lake No. 1,6107' -28' The clear areas are quartz, the grey mostly microcline and oligoclase. A very little brown biotite and black magnetite is present. Very similar rock is known to be arkose more or less metamorph-os e d by nearby doleritic intrusives.

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66 BUREAU OF GEOLOGY a r e regarded in this pape r as r epresenting middle C r e t aceo us r oc k s and the we ll is ass um e d to b e in Jurassi c a t the bottom of the hole. In this c on n ec tion it might b e m entioned th a t S chuc h ert r e gards granit es in C entra l C uba as having b ee n intrude d at the end of the Jurass ic. Dic k e rson also not e s the assoc iati on o f g r anite with his Oxf o rdi an." ORANGE COUNTY WARREN PETROLEUM CORP. GEORGE TERRY NO 1 S ec. 21 T23S R 31E Cente r SWJ4 SEJ4 T.D 65 89' Com pl e t e d 195 5 Well localit y 17. Top of gran it e a t 6550'. Only cuttings. No samples a v a il a bl e D ata from Applin (per so n a l c ommunication 1 967 ) I NDIAN RI VER C O UNTY AME R ADA PETROLEUM C ORP. FONDREN MITCHELL N O. 1 T.D. 9488 S ec tion 28, T31S R35E 1980 S an d 1980 E of NWJ4 S ec. 28 Compl e t e d 1 95 6 W e ll l oca lit y 18. T o p of weathe r e d (?) i g n eo us r ocks a t 9410 Ro c k r e po1t e d as andesit e' Applin ( p e r sona l commun ic a tion, 1 9 6 7 ) Sampl es (cuttin gs) av ail ab l e as f o ll ows: 9424-29 9454-64 9429-34 946469 2434-39 "9469-74 Figures 44 45 9 4 39-44 94 7 4-79 "9444-49 Figures 42 43 9479-84 9449-54 "9484 -89 T.D. Figure 46 All in vo lcanic ro ck. Thin sections as follows 9444-49 Brown basalt, consists of fresh calci c plagioclas e l a ths with co lorl ess to greenis h or reddish monoclinic p y rogen e and blac k ilm eni te. Gre e n t o brow n chlo rit e with ilmenite forms s mall seg reg ations in the rock. 9469-7 4 Amygdaloidal cal ci ti c b asa lt; basalt with muc h calcit e v e ins and c hl ori t e amygdules. Figures 44 and 45 (?) 9484-89 Amygdula r basalt. Muc h calcite, c hlorit e and quartz in amyg dules. Figure 46 The r oc k co ul d b e t e rm e d a mode r a t e ly a lt e r e d amygdaloida l bas alt. It app ears t o b e very s imil a r to th e amygdal o idal basalt from Appling County Georg i a and illustr a t e d by Milt o n and Hurs t ( 196 5);

PAGE 67

BULLETIN NO. 55 67 Basalt Figure 42 Amerada Fondren Mitch e ll No. 1 Indian Riv e r County, 9444'-9449 ', Ordinary li ght x 35.

PAGE 68

68 BUREAU OF GEOLOGY Diabase with inte rstitial chlorite-ilmenite. Figure 4 3. Am e r a d a Fondre n Mitch e ll No 1 India n River C o unty, 94 4 4 -9449 Shows plagiocla s e laths and augite with ilm enite and g r een chlorite w ith bl a ck ilm enite aggre g a t es. The chlorite vari es in color from green to brown. Ordinary li ght x 150.

PAGE 69

BULLETIN NO. 55 69 -Figure 44. Amerada F ondre n Mit c h e ll No. 1 Indian Riv e r County, Florida 9469'-9474'. Calcite-chlorite-quartz segregations in b asa lt. The large mass (left of center) is cal c ite, bordered with (clear) quartz Ordinary light x35.

PAGE 70

70 BUREAU OF GEOLOGY Figure 45 Amerada Fondre n Mitch e ll No. l Indian River County, Florida, 9469' 9474'. D e tail of Figure Amygdaloid a l b asa lt. Shows amygdaloid in cente r of picture with green ch l orite (g ray a r eas), pl ag i oclase l a ths qua rtz, and ilmenite; the large grey areas at top l e ft and right are calcite, and the clear areas bordering the calcite a r e quartz. Ordina ry light x 150.

PAGE 71

BULLETIN NO. 55 71 Figure 46. Amerada Fondren Mitchell No. 1 Indian River County, Florida, 9 484'9489' T.D. Basalt, with considerable quartz (most of the light-colored areas in the picture) Green chlorite, calcite, and ilmenite are also abundant. The plagioclase feldspar is fairly fresh, but the augite is mostly altered to ob scurely crystallized chloritic aggregates. Ordinary light, xl2. and indeed, to the amygdaloidal basalts of northern Florida described elsewhere in this repmt. Figures 47a and 47b show the appearance of the rock in thin section. A chemical analysis is given in Table 3. Dating by Grasty (Table 2) gave a K-Ar age of 89.3 + 2 m y (middle Cretaceous). 12744' In hand specimen resembles the preceding. In thin section however it is markedly different. The texture is fine grained granitic, and th,e rock consi sts essen tially of quartz and moderate ly sodic plagioclase, near

PAGE 72

A m ygda l o id a l b asa l t Fi g ur s 47a, b Amerada P e tro leum Co., Cowie Magazin e o 2, St. Luci e County, F lorida, 127 34'. 47a ( ordin a ry light) Show s p r oportion of black ore grains and feldspar, a nd s h a p e a nd s iz e of whi c h contai n pal e green ch l orite apparentl y i d e ntica l to t h e inte r t i t i a l c hlori t e r e pla c ing augi t e, e tc. wh i ch i s compl e t e l y gone. 47b (c ross e d n i co ls). T h e tw i nn e d p lagi o c l as e f e l d s pars are the mo s t abundant min e ral; th e blac k areas are most l y pal e green chlori t e and ilm enite O r d i nary light and c ros se d ni o ls, Xl6.

PAGE 73

BULLET! 0 55 73 andesin e in com p osition It shows little alte ration usually no more than a f e w minute c hl oritic flecks. The r e is v e 1 y little of the green chlorite abundant in 1273 4'; what th e r e is, is mostly assoc iated with opaque ore grains, surrounding and filling c racks in these One or two are as sugges t olivine now r eplace d by ore and chl o rite. No hornblende, abundan t in th e following 12748' rock i s present; but there i s much brown biotite mostly h e avily altered t o brown chlorit e? ser p entine? Often the biotite and its alte ration produc t contain a n e twork of rutil e needl es h exago n a ll y orient ed. Apati t e is a minor accessory. Many of the rather coa r se black ore grains are shattered and chlorite-serpentine fills th e cracks. Figures 48a and 48 b show the microscopi c aspec t of this rock ; and a c h e mi ca l anal ysis is given in Table 3. Dating by Grasty (Table 2 ) of this ro c k by K-Ar gave 226 6 m.y. and 224 3 m.y. ( late P e rmi a n or ea rl y Triassi c ) Bass howeve r (Table 2, ob t a ined t wo widel y diff e r ent K Ar ages for samples from this core from 148 m.y (middle Jurassi c) to 3 99 m.y. (la t e S iluri an or earl y D evonian) and for a third, by strontium isotopes 530 m.y. (middle Cambrian). 12748 This rock a l so r esembles the two preceding superfi cia ll y, but in thin section diff e rs markedly from both. It has a rath e r coar sely granula r t exture and consists esse ntially of un alte r e d green hornblende, quite fresh calcic plagioclas e, and quartz. The coarse black ore grain s ( ilm enite?) are unfracture d A littl e brown bio tite is present, som fr es h but most heavil y a lt e red to vague brown chlor itic mate rial. Very f e w and small areas of pale green c hlorit e s imilar to tha t in 127 34. and 12744' with irregular outlin es are prese nt. Typical a r ea s in thin section a r e s hown in Figures 49a and 4 9b. This rock has been K-Ar dat e d by Grasty ( Tabl e 2) 308 5 m.y. (upper Mississippian o r lower Pennsylvanian ) and the hornblende from it by Bass also K-Ar (Table 2 ) 470-503 m.y (uppe r Cambrian or low e r Ordovi cian ) Obviously th ese dates do not agree too well, and their precise signifi ca nc e is unc e rtain.

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Granite Figures 48a, b Am erada P etroleum Co. Cowle s Magazin e No. 2, 12744', St. Luc i e Co., Fla. Thin section, ordinary light and c ross e d ni co l s X6. The light colored a re as (ordinary light) a r e quartz and ande sinic plagioclas e ; the gray areas are brown a lt e rati o n produce s of hornblende, now mainly alte r e d biotite, or chlorite The sma ll blac k areas (low e r ri ght) a r e mostly black iron (titanium) oxide, probably ilm e n, with a littl e pyrite. They have been s h atte r e d and the crack s fill e d with serpentinic-chloritic material.

PAGE 75

Diorite Figures 49 a, b Am e rada P e trol e um C o Cowl es M agaz in e No. 2, 12748' St. Luci e Co., Fla. Thin sec tion, ordin a ry light and c ross e d ni c ols X6. Sho ws abundant un alte r e d g reen hornbl ende and c alci c plagiocl ase, with minor quartz and black opaque ilm enite(? ) CJl CJl

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76 BUREAU OF GEOLOGY ST. LUCIE COU TY AMERADA PETROLEUM CO. COWLES MAGAZI E NO.2 Completed 195 7 W e ll lo ca lit y 19 12749 T.D. Three sp ec im ens of larg e size cor w e r e r eceiv d from Paul L. Applin through E. J H nd e rson G eo l ogist Am e r ada P trol e um Co. August 20, 1957 from 127 34, 12744 ', and 1274 8' Th thre rock a lthough th y cover a r ange of only 1 4 feet show r e mark able div e rsity. Wh r eas th e up P rmost roc k 12 734', ca n b r ea dil y id e ntifi e d as bas a lti c, th e middl e sp cimen 12 744' has a granitic as p ec t and th e bottom roc k 12 748. would p a s as c ommon diorite. The two low e r core samples hav e b ee n studie d in considerab l e d t ail b y B ass ( 1969 ) with age determinations ; simil a r tudies of a ll three cor s are given h e r e 12734 is a h ard gray ro c k mottled with white flecks of ca lcit e a c nti m e t e r across and hawing bl ac k s li c k e nsid d SUJfaces In thin ec tion it how a uniform aggr gate of andesinic plagioclas laths with abundant small e uh e dral bl ac k ir o n oxide ( ilm e nit "?) grains. Almost as abundant as th e plagioclas e is green ch l orite, inte rstitial to th e f eldspar and evide ntly a r eplacement of pre e xisting mafic min e r a l probably p y roxene. Similar ch lorit e showing low bluish int e1fe r e nce colors under crossed nicols -al so forms sph e rical vesicles or bl e bs a coup l e of millim e t e r across. Around and contiguous to th e se, the black ore grains ar r e pla ce d b y brown sph e ne. Irregular small p a t c hes of ca lcit e a r e strewn through th e ro ck. The f elds p a r s in this rock a r e fairly fresh mo s tly appar e ntl y unalte r d. Th y are somewhat fissure d th e fissur es being fille d w ith g r ee nish c hlorit OSCEOLA COU TY, FLORIDA HUMBLE OIL A D REFI I G CO. W. P HA YMA 0. 1 T.D. 8798' Compl e t e d 1946 W e ll lo ca lity 20 Applin ( 1951 ) o. 24 This is on e of two w lls in Osc eo la County ( th e other being th e Humble Oil and R efinin g Co Ra y Carroll o. 1 ) Sampl es are avai l able from 8619 to 8793!2', with inte rruptions Rhyolit e from 8781' has b ee n K-Ar dated 173 4 m.y. ( Low e r Jurassic ) b y Grasty ( Tab] 2 ) 58 f ee t of rhyo lit e, to 8798 ( T D. ) wer drill e d. Co-re No. D epth 253 619 -8629 254 8655' -8658 Friable gray sa ndston e Gra y slickensided shale with coarse qua1tz grains. In thin section seen to b e large l y volcanic d e bris, probably as h. The quartz grains show no rounding a nd many show secondary en l argement.

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255 256 257 258 259 260 262 8734' -87 44' r ecove ry 5 ft. 87 44' -8750 8750 -8756 8753 -8756 8756 -8759' 8759' -8765' 8765 -8770 263 8770 -8772' 264 8772 -8775 265 8775 -8778' 266 8778' -8780' 271 273 275 276 8781' -8781!f' 8781 W -8783' 8786 -8787' 8789 -879 0 BULLETIN NO. 55 77 "Top 4 ft. of core is gray and black con glomerate sancl Bottom 1 ft. of core is por phyry wi th and intrusions. ( Drillers log ). Sample con i ts of small hard gray igneou rock fragm e nts with sandy debris. Top 1 ft. gri tt y clayey rhyolitic arkose. Consists l argely of sub angu lar fragm e nts of quartz, mi ro-pegmatite, and sodic f e ldspar, with int e rstiti a l clay ey matrix. An oth e r sample of th e same pi ce of core included both sandstone and volcanic rock fragments. ext to the top 1!f ft. rather firm carbonaceous (coal? ) material. B ottom six inches rhyolite fragm e nts. Slat e-g ray stony tuff(?) with smal l aphani ti c inclusions and white kaolinized feld spars. Microscopic: quartz and o li goclase-ande sine phe nocrysts in feldspathic ground mass. Quartz euhedral (rhombohedra and prisms), a l so ph e roidally t:ound ed. Plag ioc l ase in part calcitized; no albi t e twin ning, only Carlsbad. No mafics very scanty ch lorit e and apatite. ( Fig. 50, Rh yo lit e) Very much lik e core 257 8750' -8753 very small homblende and biotite calcite patches. ( Figs. 51a and 51b) Rh yo lit e 173 4 m. y Lower Jurassic ( Tabl e 2 ) Dark gray stony rock with r e d feld par ph enocrys ts. Quartz and albitic-oligoclase phenocrysts in microcrystalline matrix. o mafics. (Figs. 52a and 52b) Same

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78 277 279 280 BUREAU OF GEOLOGY 8790' 8792:11' 879sJr -8796W Sam e Rhyolit e Fi g ur e 50. Humbl e Oil a nd R e fining Company, W. P. H ay m a n o. l Osceo l a County, Florida Cor e 257 8750' -8753' R ounded a nd s ub round e d qu a rt z p h e n oc ry s t in fine graine d f e l sic groundmass. Near th e center i s a s mall sod ic p la gioclase ph e nocry st. Ordinary li ght Xl7Jt

PAGE 79

Porphyritic rhyolit e Figures 5la, b. Humble Oil and Refining Co. W. P. H ay man N o. l O sceo l a County, Florida, Cor e 262, 8765 -8770 ft. Shows rounded qua rtz phe noc r ysts and l a r ge sodic plagiocl ase in finegrain e d felsi c groundmass. Ordinary light and c ro sse d ni c ol s c.n c.n

PAGE 80

Rhyolite Fi g ur es 52a b. Humbl e Oil a nd R e fining Co., W. P Hayman No 1 O sceo l a County, Florid a Co r e 275, 8786-8787 ft. R ounde d quart z an d sodic plagioclas ph e nocrysts in a fine-g r aine d fel s i c g r oundmass, which is oarse r in irr eg ular st reak s Ordinary light and c r ossed nicols Xl7)f. 00 0

PAGE 81

BULLETIN NO. 55 81 OSCEOLA COUNTY HUMBLE OIL AND REFINING CO. J RAY CARROLL NO.1 8 044W T.D. W e ll locality 21 Applin ( 1951 ) No. 6 Applin ( 1951 ) lists the 14 feet of bottom rock in this w e ll as "altered and veined biotite granite" as d etermined by F. F. Grout. H e also giv es T D. as 8049 ft. This is one of the three "metamorphic basement" wells in central eastern Florida (the other two Volusia County Powe ll Land Co. No. 1 and Lake County Oil Development Co. South Lake No. 2 -J. R. Arnold No. 1 ) which led Applin (1951, Fig. 1) to indicat e a triangular area of several thousand square miles including all or p art of Volusia S e minole Lake, Orange, Osceol a, Polk, and Brevard Counties as underlain by "pre-Cam brian granite, diorite and metamorphic ro c ks." Bass ( 1969 ) describes rock from this well as quartz monzonite. Material studied from this well is: Core 174 7904 -7914' Core 175 7965 -7975' Core 176 7975 -7984' All of these are sand and friable sandstone. Core 177 8034' -8042' The top of the ign eo us rock is in this core (P. L. Applin). Core 178 8042'-8042Jf T.D. Both of the last two cores a r e of similar rock, granitic in appearance, with much coars e pink f eldspar and green c hloritic areas. Microscopically it resembles a hydrothermally altered aplite, containing abundant quartz and kaolini ze d-s ericitized albite-oligoclase with veins and replacements of calcite; potas h feldspar, with small optic angle (sanidin e?) is sparingly pre sent. Green chlorite, strongly pleochroic, apparently originally biotite is the only m a fic mineral. Minor accessori es are magnetite -ilmenite l eucoxene, apatite, and an occasional zircon. Three thin sections show little variation. This rock h as been date d by Bass (1969) by Srs7/Sr86 as 530 m.y. The rock is shown in Figures 53a and 53b.

PAGE 82

Figure 53a. Humbl e Oil and R efining Company, Ray Carroll No. l Osceola County, Florida, 8042' The light co lored a r eas a r e anhedra l quartz, whose suture d aggregates are s h own w e ll under crosse d nicols. Th e g r ay a r eas a r e euhedral so di c pl ag iocla se; th e black a r ea, righ t cen t er, i s magnetiteilm enite, w ith many fractures filled with g reen c hlorit e; th e dark mass jus t t o the right of thi s i s c hl o rit e with many s m a ll inclu s ion s o f l e u coxe n e, o rigin a lly ma g n e tit e-i lm enite. Ordina ry li ght Xl5.

PAGE 83

Figure 53b. Humble Oil and Refining Co. Ray Carroll No. 1, Osceola County, Florida. 8042'-8042Jr. The light colored a r eas are anhedral quartz, whose suture d aggregates are shown well under crossed nicols. The gray areas are euhedral sodic plagioclase; the black area, right center, is magnetite-ilmenite, with many fractures filled with green chlorite; the dark mass just to the right of this is chlorite with many small inclusions of leucoxene originally magnetite-ilmenite. Ordinary light Xl5. C!l C!l

PAGE 84

84 BUREAU OF GEOLOGY OKEECHOBEE COUNTY AMERADA PETROLEUM CORP. MARIE SWENSON N0. 1 T.D. 10838' Completed 1955 Well locality 22 Sec. 5, T. 36 S., R. 34 E. Center "Top of volcanic rocks 10,750 ft." P. L. Applin (written commun., 1967). Reference: Applin and Applin (1965) 9 samples (cuttings) available: 10750' 60' All mostly grains of quartz, anhydrite and more or "10760 70' less igneous rock with contact rock ("baked shale") "10770' -80' fragments. 10780'-90' 1 0790' 1 0800 10800' 10' 10810' 20' 10820'-30' "1 0830' -40' "Thin sections 10760'-10770' Thin sections were made of 6 grains; these were basalt, consisting of fairly fresh calcic plagioclase laths with green chlorite, cal cite, and ilmenite; the fourth was perhaps a chilled phase of this basalt with obscurely crystallized feldspar in a heterogeneous fine grained ma trix with much ilmenite; the other two were hydrothermally altered shale (Figures 56 and 58) F i g 54 shows a chlorite-quartz amygdule in the basalt. Fig. 55 shows another cal citic basalt fragment, not amygdular. 10770'-10780' Thin sections were made of 8 grains, all basalt, some amygdular. Figure 59 shows an amygdule consisting of quartz and chlor ite. The basalt consists of plagioclase feldspar (reddish in thin section), chloritized amphibole, chlo r ite, with much rather coarse black ilmenite. 10830' 10840' Includes 6 thin sectioned grains, all but one basalt sim ilar to the preceding. The other consists of chalcedonic quartz with pale greenish chlorite or clay mineral with calcite and black ilmenite; perhaps hydrothermally deposited. Figure 60. OKEECHOBEE COUNTY SUN OIL CO. AMERADA PETROLEUM CORP. HARRIS-HOLMES NO.1 T.D. 9840 ft. Completed 1966 Well locality 23 Sec 8, T. 33 S., R. 34 E. "Top of rhyolite porphyry 9682 ft." P L. Applin (written commun., 1967). No specimens available.

PAGE 85

BULLETIN NO. 55 85 Amygdular basalt Figure 54. Okeechobee County, Florida, Amerada Swenson No. l, 10760' -10770' Amygdule, consisting of quartz and ch lorite. The b asa ltic matrix is obscurely c ryst a llized with mu c h ilmenite. Ordinary light Xl50.

PAGE 86

86 BUREAU OF GEOLOGY Fi g ur e 55. m e rad a S wenso n o 1 Ok eec h obe County Fl o rid a 10760' 10 770 Show s thre frag m ent of b asa lt non-amygdu l a r Ordinary lig ht x35

PAGE 87

BULLETIN NO 55 87 Figure 56. Am e r a d a Sw e n s on No 1 Okeec h o b ee County Florida. 10760 10770'. Shows three fragm ents, a ll diffe r e nt. L e ft sandy hydro th e rm ally a lt e r e d s h a l e, lower center, fine-g r a ined clay ey alte r e d s hale; right a m ygdu l a r basalt, a l so shown in Figure 54 Ordinary light x32.

PAGE 88

88 BUREAU OF GEOLOGY B a s a lt Fi gure 57. Amer ada Sw e nson No. 1 Ok eechobe e County, Florida. 10760 -10770'. Sh ows plagi oclase l aths, ilm enite, w ith c hl orite and ca lcit e This g r ain i s a l s o shown in Figure 55. Ordinary light xl50.

PAGE 89

BULLETIN NO. 55 89 B a k e d shal e Figure 58 Amerada Swenson No l, Okeechobee County, Florida. 10760' -10770' S ho ws a n gular quartz particles in ob scure se ric iti c fine graine d clayey (?) mat rix. Ordinary light xl50.

PAGE 90

90 BUREAU OF GEOLOGY Amygdular basalt Figure 59 Am erada Sw e nson No l, Okeechob ee County, Florida. 10 770 '10 78 0 Amygdu l e cons ists of clear rounde d quartz (white) with bright green bands of platy ch l orite Figure ... a l so illu strates this grain. Ordinary light Xl50.

PAGE 91

BULLETIN NO. 55 91 Figu r e 60. Amerada Sw e n so n No. 1 Okeechobee County, Florida. 10830 108 40' T.D. H ydrothermal quartz (c h alce donic) c hl o rit e ca l cite ilm enite ro ck. Ordin a r y li ght X150.

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92 BUREAU OF GEOLOGY HIGHLA DS COUNTY HUMBLE OIL A D REFI I G CO G. C. CARL TO ESTATE NO.1 Compl e t e d 1946 Well l oca lit y 24 Applin ( 1951 ) o. 2 1 This well drill e d 367 ft. in ign eo u s r oc k th e grea test thickness p e n e trated b y any w e ll in Florida. Applin ( 1951 ) r eports th a t it drill e d in "amyg d a loid a l b asa lt rhyolite porphy 1 y and r e l a t e d kind s of i g n eous ro ck." It is a l so th e sout h e rnmost of th e w e ll s in F lorid a that hav e e n counte r ed i g n eo u s ro c k, as well as th e d ee p e st. A very l a rg e co ll ection of s a mpl es, from core No. 335 12563 -1267 3' t o Cor e o. 379, 12982 -12 98 5' ( T .D. ) i s ava il ab le. DESCRIPTION OF SAMPLES Core 335 1256 3 -73' r ecovery 6)f ft. top ft. is friable pinkish white sandston e bottom 1 ft. i s r e ddi s h powdery ea 1th y m a t e rial mostly sand g r a in s as in top ft. Th e r a r e a l so frag m en ts of brown sha le, and at l eas t o n e mall f r agme nt of mate ri a l som ew h a t lik e th a t o f th e n e xt co re. Core 336 1261 8'-25' ("top of i g n eo us a t 12618 '," Applin) top 3 ft. i s brown fine-g r a in e d sha l e .(?) ash (?) or a lt e r e d vol ca nic ro ck. It is now f e rruginous clay wi th gree n seco n dary c lay min e rals a long s li c k e nsided surfaces. Bott o m 4 ft. is g r ee nish vol ca ni c ro c k int e rlay e r e d with calc ite. Core 338 12664 -67' r ecove r y 2 ft. is gr ee nish grey volcani c ro c k, with sparse f eldsp a r phe no crys t s and zeo liti c coa tin g o n fractur e pla n es Roc k from 1 2664 ft. h as b ee n d a t e d 1 83 10 m.y. Trias s i c Jur ass i c ( T a bl e 2 ) Core 339 12667'-72 r ecove 1 y 8 ft. (? C.M. ) is fine g rain e d r e d volca ni c (ash ? ) In thin ec tion appear s t o b e a hi g hly a lt e r e d as h now es sen ti ally f e rru ginous clay H oweve r it may b e a lt e r e d massive volcanic Core 340 12672 -78 r ec ov e ry 6 ft. This is a highly amygda loid a l brown volcanic r ock. Core 341 12678 -84 r ec ov e ry lJ f ft. sim ilar to prece ding. Cor e 343 12689 -94' r ecove r y 5 ft much lik e co r e 338 above. Core 344 12694 99' r ec ov e1 y 4 ft. S a m e as preced ing. In thin section shows a n ori gina l fine g r a in e d b asa lti c structu re, with m a rk e d hydr o th e rm a l a lt e r a ti on of th e original co nstitu e nts. Th e o rigin a l g la ssy ( ? ) m a trix i s n o w a g r ee nish-brown obscure agg r ga t e of ch l oritic, am phib o le ( ? ) bio tit e (?) ca lcite, e t c Ori gina l ilm enit i s no w le u coxe ne. Th e f eldspa r lath s are on l y s lightl y a lt e r ed. V e inl e t s of g r ee n ch lorit e ( ? ) o r se rp e ntine(?) trav e r se th e r ock. ( Fig. 61) Core 345 12699 -1270 8' R e cov e ry 4Jf ft. Sam e rock as prece ding. Cor e 346 1 2708' -12715 R e cov e r y ft. Simil a r to prece ding, with mark e d a lt e rati o n e ff ects ze oliti za tion ca lciti za ti o n e t c with shearing

PAGE 93

Figure 61. Humble Oil and R e finin g Company, G. C. Carlton Esta t e No.1, Hig hlan ds County F l orida. 1 2694'-12699'. Bas alt w ith gree n v e inl et. XIS.

PAGE 94

94 BUREAU OF GEOLOGY Core 347 12715'-12721 top 3 ft. fin e grained brown basalt. In thin section shows obscurely crystallized groundmass with scattered smal l chl o ritized plagioclase (?) crys tals. ( Fig. 62 ) Bottom 3 ft. similar to preceding. Core 348 12721' -12722' Composite volcanic rock, part brown, part green. The green appears to cut th e brown, and may b e of h ydrothermal origin. In thin section the green mat e rial i s seen to be c hloritic calcite. (Figs. 63 and 64 ) Core 350 12766'-12771' R ecovery 23f ft. grey green fin e grained volcanic. Core 351 12771 -12775 Sam e as preceding. In thin section shows the usual fine grained felsic groundmass, crowded with black opaque iron oxide particles. A chloritized mafic phe nocryst i s present; they are not common in th e rock from thi s well. (Fig 65 ) Core 352 12775 -12778 recovery 3 ft. H eav ily slickensided greygree n vo lcanic rock. Core 353 12778'-12783' recov ery 4 ft. fin e grained grey volcanic. Core 354 127 83'-12786' r ecovery ft. fine grained grey and brown volcanic, showing the usual hydrothermal al t eration. Core 357 128033f' -12805' gr y volcanic. Core 358 12824'-12827' r ec ov e ry ft. green and brown volcanic. 12826 '-12827' amygdaloid a l basalt ( Figures 66 and 67). Core 360 12837'-12847' recovery 23f ft. brown vo l canic, with green (c hloritic ) amygdul es. Core 362 12852'-12857' same as prece ding. Core 363 12857'-12862 same as preceding, with pink amygdul es ( h eulandite?) Core 367 1287 8'-12885' recov e ry ft. Sam e as prece ding. Core 368 12928'-12932 Sam e as prece ding. Core 369 12932'-12936 Sam e as prece ding. Core 370 12937'-12940 Sam e as preceding. Core 371 12940'-12945' heavily slickensided (sheared) volcanic lik e preceding. Core 373 Core 374 Core 375 Core376 12948 -12949 Sam e as prece ding. 12970'-12972 r ecove r y ft. 12972 -1297 4' recov e ry ft. 12974'-12976 "recovery 6ft?" (thin section-see b e low ) Core 377 12976'-12979' recov e 1 y ft. (thin section-see b e low ) Core 378 12979'-12982 recov e ry ft. Core 379 12982 -12985 T.D. r ec ove1y ft. All of th ese cores are of similar mate rial diffe ring markedly from th e preceding.

PAGE 95

Figure 62. Humble Oil and Refining Company, G. C. Carlton Est. No. 1, Highlands County, F l orida, 12715 -12721 CJ( CJ( Fin e grained basalt with microporphyritic f e ldspars (?) r eplaced by quartz-c hlorite. The roc k is stained r e d by fine grained limonit e X18. 3i

PAGE 96

96 BUREA U OF GEOLOGY Ba a lt Fi gure 6 3 Humble Oil and R e finin g Company, G C. Carlt o n E s t a t e o. 1 Hi g h lands County, Florida 12721 '1 2 72 2' The ve in (upper right) i most l y ca l cite with a littl e g reen ch l o rit e. Xl8.

PAGE 97

Figure 64. Humble Oil and R e fining Company, G. C Carlton Est. No.1, Hi ghlands C ounty, Flo rid a, 12721' 12722' B asa lt w ith qua rt z-c hl o rite-cal c it e ve ins. Chlorite i s the m a j o r min e r a l in th e v u gs a n d veins s hown N o t e bro k e n ve in lower l eft. Ordinar y li ght X18. Cl1 Cl1

PAGE 98

98 BUREAU OF GEOLOGY B a s a lt Fi g ur e 65 Humbl e Oil a nd R e finin g Comp a n y C a rlt o n No 1 Hi g hl ands C ounty Fl o rida. 1 2 771 -12 775 '. Show s typi c al o b scure l y crys t a lli z e d g r oundmass o f vo lcani c ro c k w ith a c hl o riti z e d p h e n oc ry s t o ri g in aily._,?liv in e o r a u gite Ordin a r y light

PAGE 99

Am yg d a l o id a l B asa lt Fi gu r e 6 6 Humble Oil a nd R e finin g Compa ny, G C. Carlt o n E st. No.1 Hi ghla nd s County, Fl orida, 1 2 8 2 6 1 282 7'. Sh ow three o f abundant a m yg d u l es in thi s p a rt o f th e basa lt The m a trix i s th same a s i n th e o th r s p ecim ns, but a m ygdul s wer e found on l y i n t hi s o ne. Th ir miner a l ogy i s r a th e r compl e x ; t he major mine r a l s a r e c h a l c doni e (?) q u a rtz, r a di a l g reen c hl o rit e a nd zeo lite. The d ark a rea (right in uppe r a m ygdule) i s lim o nit e, w hi c h i s abundant in th e m a trix, to ge ther w ith mag n etite g r a ins. Ordina r y light X18.

PAGE 100

Figure 67. Humble Oil and Refining Company, G. C. Carlton Estate No 1, Highlands County, Florida, 12826 -12827' Amygdaloid in basalt. Shows a large amygdaloid, about a centimete r across, w ith complex structure and min e ralogy. The light color e d a r e a with (two ) good cleavages a t right angl e s a r e c oarsely crys t a lli ze d zeolit e ; th e darker areas a r e chlorite; there is also limonite (black) and chalcedonic quartz (whit e are a). X27. ...... 0 0

PAGE 101

BULLETIN NO. 55 101 Th e specim e ns are coa rs e grained, pink, and to a l esse r ex t ent, g r ey in co lor and sup e rficiall y r esemble w eathe r e d orthoclas e g r an ite. Howe v e r they a r e all vo lcanic ro c k appare ntl y a gg lomerate wi th d e finit e volcanic ash (shard structure) Core 376 12974-12976 consists of equal amounts of coa r sely crystallized r e d zeoli t e, stony g r ey r oc k and a g reen c hloriti c mate ri al. The ston y grey ro c k is a fin e grained rh yolitic tuff, with scarce quartz phe no c rysts. Th e s e ar e s h atte r e d and partl y r e sorb e d. The matrix of the s e phe no crysts s hows characte ristic shards, indicativ e of e xp losi v e r e l e as e of in t e rnal gas -pr essures. Calcite is pre s ent in thin vein l e ts. Core 3 77 12976-12979 This is a rh yo lit e porphy r y, with nume rous phenocry sts more or l ess r esorbe d but c h em ically unalte r e d of albitic plagioclas e and quartz. Th e f e w mafics ( p y rox e n e?) are c hloritized. HIGHLANDS COUN TY CONTINENTAL OIL CO. G. C. CARLTON, e t al. T.D.1263 0' Comple t e d 1955 W e ll locality 25 Sec. 20 T. 38 S., R. 28 E C ente r "Top of volc a ni c ro c ks (?) core 1 3 at 12,601 ft P. L. App lin (writte n commun. 1 967 ) R e f e r e nc e App lin and Applin ( 1965 ) Sp e cimens availabl e and exa min e d as follows: 12600 -12609 Top Fine grained bl ac k ash (?) with r eddish areas ( h ematitic) and w hitish ( cl ayey) streaks. In thin s ection, s ee n to b e a lt e r e d b asa lti c ash, with mu c h fine l y -di vide d r e d t o black h ematitic dust, and irregul a r sch li e r e n and vesicles of whitish clay e y mate ri al. No m afic min e r a l s r e main and th e pla g ioclas e l a ths are alt e r e d and outlin e d b y h e ma titi c dust. Figure 68 Middl e R e d bas a lt with c l ay and ca lcit e Bott o m Brown finel y gra nul a r b asalt with co nspi c uous lighter colored ca l c it e bands 1 o r 2 mm wide The cal c it e is granular, and is associat e d with white or g reeni s h c lay ey v e sicles and schlier e n. The se are a l so abundant in th e bas a lt in w hich the r e is littl e calcit e No maffic min e r a l s r emain in the. b asa lt whic h is h eav il y impregnated with black h ematitic dust. Figure 69.

PAGE 102

102 BUREAU OF GEOLOGY Figur e 68. Contin ental Oil Co. G. C. Ca rlt o n No 1 Hi ghlands Coun ty, 12600 1 2 609 top. H e t e r ogeneous a lt e r e d b asa l tic as h w ith claymin e ral v e inl e t s Ordin a ry l ight X23.

PAGE 103

BULLETIN NO. 55 103 Figure 69. Continental Oil Co., G. C. Carlton No.1, Highlands County, 12600 '12609' bottom. B asa lt with ca lcite bands. Ordina ry light X13.

PAGE 104

104 BUREAU OF GEOLOGY 1261 4'1 2630' Top Middl e Lower middle Bas alt, with c h a lcedony (?) a mygdul es and veins and dissemina tions of ca lcit e 1 o m afics a ll r eplaced b y chlorite and calcit as is a lso much o f th e f e ldspar. A littl e quartz is associated with th e calciti c v e ins. The l a rger a m yg dul es have a n inne r g r ee ni s h co r e within a fin e-g r a in e d co l orl es s zo n e (Figure 70 ) Complex ve inl e t s containing green chlorite, r e d h e ul a ndite (?), quartz and c al c it e c ut the basalt (Figure 71) B ottom B asalt with c h alcedo n y (?) amygdul es and minor ca l c ite. No unalt e r e d mafics ( n o t ca l citi ze d but r epresente d by o bscure d ebris and bl ac k ilm e nit e) The l a rger a mygdul e s con t a in an inne r co r e of o li ve g reen chlorite surrounde d b y fine l y c r ys t a lli ze d white chalcedony ( ? ) (Figure 72 ) 12629 T.D. Amygd a l oidal b asa lt (Figure 73)

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BULLETIN NO. 55 105 Figure 70 Continental Oil Co. G. C. Carlton No. 1 Highlands County, 12614 126 30' lower middle. Zon e d c hlorit e amygdul e in bas alt. Much of the lath s haped feld spa r has been calcitized. Ordinary light X13 0.

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106 BUREAU OF GEOLOGY Figure 71. Continental Oil Co. G. C. Carlton No. 1 Hi ghlands County, Florida, 12614 '126 3 0 lo w e r middle. Amygd a loidal basa lt with complex vein l e ts, c on t a inin g green chlorite, r e d h eulandite (?) quartz, and ca lcit e Ordinary light X28.

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BULLETIN NO. 55 107 Figure 72. Continental Oil Co. G. C. Carlton No 1 Highlands County, Florida, 12614 -12630 bottom. Basalt with large (gre y ) quartz (white ) amygdul e s Ordinary light X23.

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108 B UREAU OF GEOLOGY Fi gu r e 7 3. Co nti n enta l Oil Co G C. Carlt o n No. 1 Hi g hl and s Co u n t y, Fl orida 1 2 629 B o tt o m o f h o le. Amyg d a l oid a l b asa l t w i th oli ve-g r ee n ch l o rit e a nd w h it e c h a l ce dony(?). O r dina r y lig h t X29.

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BULLETIN NO. 55 HARDEE COUNTY HUMBLE OIL A D REFI I G COMPA Y B. T. KEEN 0. I 11934 T.D. 109 Complete d 1 948. W e ll localit y 26 Applin (1951 ) No. 20. Applin puts th e top of th e ign e ous rock at 11828 ft. Sampl e s are avai labl e from 11853 t o 119 3 3 as follows: Co r e 1 81 11853 -11857' This is a fine g raine d dark g reenish gray volcani c ro c k with reddi sh stains on fractured surfa ces. No phe nocrysts are s ee n. In thin s e ction (Figure 7 4 ) an aggr e ga t e of turbid plagioclas e lath s wi th inters titi a l gre e n ch lorite ( r eplacing augite ?), rathe r abundant black ore grains scatte r e d qua1 t z ( a l so in v e inl e ts), and a littl e cal cit e i s s een. A f e w large grains a r e now who ll y chlori ti z e d and a f e w chl orit e amygdul e s are pre s e nt. This rock has been date d b y R. L. Gras t y as 1 43 7 m.y. or 147 3 m.y. (Uppe r Jurrasi c) Core 1 82 11857'-11867' This i s som ewhat coa r s e r and more g r ay than g r ee n. Co r e 183 11867'-11877' r e cov e r y 8 W Agg l om erate of rounde d dark gray mass e s up to an in c h across in a li ghte r co lore d matrix. In thin s ec ti on is seen an aggregat e of fin e g raine d or g l assy basalt fragm e nts, mostly opaque b ecause of black iron oxid e dusty pa1ticl es, but c rowde d w ith l aths of unalte r e d pl a gioclas e f eldsp ar. The matrix of th e s e fragm e nts i s p a l e gree n ch lorite with fine l y c1ysta lli zed quartz. Chl o rit e a l so fills nume rou s irregular v e s icl e s in the basalt fragnients. The r e are a l so fragm e nts of quartzite with a rim of ch l o rit e around th e fragm e nt. A f e w of th e basalt fragm e nts have large r po1ph y riti c f elds par, compl e tely un alte r e d. Figure s 75a b and 76a b show the s e f e atures. Core 1 85 11874' -11 881 fine graine d d a rk gray basalt Cor e 189 11886 -1188 8 r ecovery 2 V e ry fine graine d dark gray basalt. One pie c e of co r e h as a l arg e qua1t z lin e d vug ov e r an inc h across. The quartz is coarse ly crys t a lli z e d and th e v u g has a bande d s tru cture a t th e contact. In thin s e ction uniform fine graine d basalt, with fre sh augit e intersti ti a l t o plagioclase laths. A v e ry few larger f elds p ars and vugs with chal c edonic si li ca and bright orange-brown zeo lit e ('?) are presen t. Sim il a r r eddish brown isotropic ('?) mate rial is stre wn through th e rock with nume rous sma ll b l ack ore gra ins. The large quartz amygdul e m entione d above has a comp l e x structure, including a thin reddish zeolite band. In thin sec tion: Core 190 11888 -11890 fine g rained dark gray basalt

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llO BUREAU OF GEOLOGY B asalt with quartz v e inl e t Figure 74. Humble Oil and R e fining Company, B. T. Keen No l Hardee County, Florida, 1185 3'11857 X28.

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Figures 75a, b. Humble Oil and R e fining Company, B. T K ee n N b 1, Hardee County Florida, 11867 '11877 '. Ba sa lt with ch lorite-quartz arilygdule. The inte rior of th e amygdule i s granular quartz, th e b orde r pale gree n chlorite. The basalt h as been brecciat e d th e fissur es filled with c hlorite. Ordina r y light and c r ossed ni co ls, Xl7.

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Amygdula r brecciate d basa lt Fi gures 76a, b Humble Oil and R e fining Company, B. T. K ee n No.1, Hardee County, Florida, 11867 '11879 An o th e r a rea in sa m e thin sec tion showing porphyritic f e ldspars in basaltic fragm ent ( bl ac k ) surrounded by chlo r ite-quartz aggregat e. Ordinary light and crossed nicols X23

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BULLETIN NO. 55 Core 191 11890 11 892 same Core 192 11892 '-11895 same Core 194 11898 -11 902' same Core 195 11902 -11906' same 113 Cor e 197 11908 -11918 r e covery 4 The rock is r e d-brown and d ecomposed to an e arthy mass but miscroscopica ll y it is about th e same as core 183 ( 11863 -11877' ) above, a lthough quite v e sicular. Core 19 8 11918 -11923 fine g r a ined dark basalt Core 199 11923 -1192 8' d a rk basalt Co r e 200 11928 -119 3 0 dark b asa lt Core 201 11930'-11932 dark basalt Cor e 202 11932'-119 3 3 T.D. r e cov e ry 1 ft. The same as core 189 ( 11886 -11888' ) above, with a f e w plagioclas e phe nocrys t s in addition to the min e rals m entione d. Figure s 77a and 77b. B ass (1969) describes a core sample from 119 30 to 11932 ft. as ba sa lt and comm ents on its l ack of m etamorphism or w eathe ring. HILLSBOROUGH COUNTY HUMBLE OIL AN D REFINING COMPANY T. S. JAMESON NO. 1 T.D. 10129' Compl e ted 1946 W e ll l ocality 27 Applin ( 1951 ) o. 22 "Rhyo lit e and vo lcani c agg lomerate App lin ( 1 951 ) Samples from 9995 to 10125' have bee n studie d The w e ll according to Applin drill e d into 119 feet of vo lca nic rock, begirining at 10010 Core 1 22 9995'-10003 is a gray arkosic gritt y sandstone, most l y slightly round grains of quartz with some microclin e The r e is consid e rabl e isotropic (?) inte rstitial mate ri a l perhaps halloysit e One quartz gra in has numerous tiny pale blue tourmaline cry sta ls. No vol c anic mate rial was seen in thin section (Figures 78a and 78b). Core 123. 10003 -10010 is similar to preceding, howe ver, th e top 2' 10 from which a thin s e ction was made shows that th e clayey ( ? ) matri x i s r ecry s t a lli z e d to a sericitic aggregate ( Figures 79a and 79b ) Core 124 10010 -10019 is a hard r e ddish rhyolitic agglomerate, v e ry si lic eous in thin s e ction show ing large areas of microgranular quart z b e sid e s nume rous euhedral "high-t empe rature quartz crys t als. Large f eldspar cry stals a r e numerous. Flowage is s ee n in thin s ec tion (Figure 80 ) Ross ( 1956 ) has d e sc rib e d this rock as w e l d e d tuff. Core 1 25. 10019 -100 22 simi lar to pre ceding. Under a binocular, specular h ematit e w ith gr e en c hlorit e is s ee n in microscopic vugs. In thin s ection micro-granular quartz wit h som e ca l cite and epidote is se e n Figure s 81a b illustrat e this rock 10025 Similar. The co lor of the cor e changes abruptly ; on e sid e

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Basalt Figures 77a, b. Humble Oil and Refining Company, B. T. Keen No.1, Hardee County, Florida, ll932'-ll933' This specimen is markedly different from the preceding, being much like a normal fine grained diabase. The r e is alteration of the plagioclase or augite or abundant magnetiteilm enite. The veinlet howeve r is the quartz -chlorit e aggregate of the other specimens. In the picture th e quartz i s clear, th e green chlorite appears gray. Ordina1y light and crossed nicols X2 3

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Arko s ic sandstone Figures 78a, b Humble Oil and Refining Company, T. S. Jameson No. 1 Hillsborough County, Florida, 9995 -10003'. Fairly fresh microc line i s seen uppe r ri ght center. Ordinary li ght and c ross e d nicols X15.

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Grit or arkose Figures 79a, b. Humble Oil and Refining Company, T. S. Jameson No. 1 Hills borough County, Florida, 10003' -10010'. Shows matrix material, rec1ystallized to a s e ricitic aggregate. Ordi nary light and crossed nicols, Xl5.

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BULLETIN NO. 55 117 Rhyolite Figure 80. Humble Oil and R e fining Company T. S. Jameson No. 1 Hillsborough County Florida, 10010'-10019' Shows quartz (clear ) in rhyolite. Many of the quartz c ryst a l s are euhedral with stron g rhombohedral d ev e lopment, characte ristic of high t em p erature quartz. The d ark e r gray a r e as are large feldspars the m a tri x mostly microgranular quartz XIS.

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Welded tuff (C. S. Ross) or rhyolite Figures Sla, b. Humble Oil and Refining Company, Jameson No.1, Hillsborough County, Florida, 10019'-10022'. This is linea ted aggregate of rhyolitic fragments, of varying texture with quartz and feldspar grains fused together. The half-circular area (lower left) is a corroded feldspar; to the right of it (center and lower center) are several quartz grains. Ordinary light and crossed nicols, XIS.

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BULLETIN NO. 55 119 reddish, the other gray. Microscopicall y, it is similar t o preceding with no evident compositional change (Figure 82 ) Core 129. 100 40' -10043 Simil a r grayish agglomerate. A thin section (Figure 83) shows charac t e risti c corroded euhedra l high t emperature quartz, and similar feldspar. Hematite is relativ e ly coars e ly crystalliz e d in patches. 10043' -10053 This shows in thin section lithophysae ("ston e bubbles") in the finely granular quartz areas. Som e contain calcite with green chlorite, most are fill e d with granular quartz. They a r e illustrated in Figure 84. 10115'-10125 This is different from the preceding ; it is a gray crystalline rock with reddish areas, ze olite or carbonate, obviously volcanic agglom erate but not rhyoliti c as the overlying rock. This is confirmed by a thin s ection (Figure 85), which shows an aggregat e o f different s01ts of fine grained rathe r basic volcanic rock. The r e are no coarse feldspars or quartz crystals, or granular quartz, as in the rh yo litic rocks above. Epidote and g reen hornblende with calcite appear to be secondary. The rock appears to be metabasaltic, rathe r than rhyolitic and resembl es to some degree the m etabasaltic rock from the St. Lucie County well, 12748'. Bass (1969) d e scribes tuff from 10106' to 10115 ; and Ross ( 1958 ) refers to w elde d tuff in three core samples between 10010 and 10034'.

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0.5 mm L___j Rhyolite Figure 82. Humble Oil and R e fining Company, T. S. Jameson No. l Hillsborough County, Florida, 10025'. This i s a typi ca l un a lt e red rhyolit e porphyry wi th quartz ( cl ear) and f eldspar phe no c ry sts (gray center) and c hlori t i c a r eas (dark gray, upper left). The groundmass shows flow lineati on. Ordinary light Xl5.

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BULLETIN NO 55 121 Rhyolite or welded tuff Figure 8 3. Humble Oil an d R e fining C ompa n y, T. S. Jameson No. l 100 4 0 100 43'. Show s euhe dral but p a rtly di sso lved hig h temperature qua rt z ( clear). At th e l e ft edge n ea r th e cen ter i s a n alt e r e d f eldspar. The d a rk spots a r e mos tly h e matitic. Ordinary light Xl5.

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122 BUREAU OF GEOLOGY Rhyolite Figure 84. Humble Oil and R e fining Company, T. S. Jameson No. l Hillsborough County, Florida, 10043'-1005 3 Shows lithophysa e ("stone bubbles") in rhyolitic agg lomerate or welded tuff. Ordinary light X27.

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BULLETIN NO. 55 123 Inte ns e ly alte r e d basaltic ro c k Figure 85. Humble Oil and R e fining Company, T. S. Jameso n No. 1 Hill s borou g h County, Florida, 10115'-101 25'. Rather co ars e ep idot e and green hornblende, with sodi c f eldspar and ca l cite, i s s tr ew n thro u g h this ro c k which r e tain s very littl e o f it s o riginal c haract er. Ordinary light, X27.

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124 BUREAU OF GEOLOGY REFERENCES Applin, P. L. 1951 Preliminary r epo rt on buried pre-Mesozoic rocks in Florida and adjacent Florida and adjacent s tat es: U. S. Geol. Survey Circ. 91 28 p Applin P. L. 1965 (and Applin E.R.) Th e Coman c h e Series and Associated rocks in the sub surfa ce i n central and southern Florida : U.S. Geol. Survey Prof. Paper 447. 84 p 1967 The Gulf Series in the subsurface in north ern Florida and southern Georgia: U.S. Geol. Survey Prof. Paper 524G 35 p. Baksi A. K. 1967 (York, D and Watkins, N. D.) Age of the Steens Mountain geomag neti c polarity transition: Jour. Ceophys. Research, v. 72, no. 24 p. 62996308. Bass, M. N. 1969 Petro g raphy and age s of c rystalline basement rock s of Florida -some ex trap o lat io ns: Am. Asso c. P etrol eum Geolog i s ts M e m. 11 p. 283-310. Berdan, J. M. 1951 (and Bridge, Josiah) Pre liminary notes on th e Paleo zoic strata beneath Levy and Citrus Counti es, Florid -a, in V e rnon R. 0., Geology of Citrus and Levy Counties, Florida : Florida Geol. Surve y Bull. 33, 256 p. Carroll, Dorothy 1963 Petro g raphy of some sands ton es and shales of Paleozo i c age from borin gs in Florida: U .S. Geol. Survey Prof. Paper 454-A, 15 p. Cole, William Storrs 1945 Stratigraphic and pal eo ntologic s tudies of well s in Florid a (No. 1 ) St Farrar, E. Mary 's Oil Corporation, Hillard Turpentin e Company No. 1 well with Ap pendi x A, Int e rpretation of th e ingneous rock in the Hillard Turpentin e Company w ell by james Osborn Fuller : Florida Geological Surve y Bul letin 26. 1964 (Macintyre, R. M., York D. and Kenyon, W. J.) A simple mass s pectro mete r for the analysis o f argon at ultra-high vacuum: Nature, v 20, 4958, p. 5 3 1 533. Fullagar, P. D. 1968 (and Bottino, M L.) T e rtiary Rb -Sr ag e of a f e l si t e intru s ion in th e Vall e y and Ridge province, Virginia ( abs.): G eol. Soc. Am erican Southeastern Sec. Ann. Mtg. (Durham, North Carolina) Prog., p. 37. Gough, D. I. 1967 Magn e ti c anonwlies and crustal st ructur e in easte rn Gulf of M exico: Bull. Am. Assoc P e t. Geol., v 51, p. 200-211. Grasty, R. L. 1967 (and Wilson, J. T.) Ag es of Florida volcanics and of opening of the Atlantic Ocean: Am. Geophys. Union Trans., v 48, p. 212213. Hills F A. 1968 (and Butl er, J. R.) Rubidium-strontium dates for some rhyolites f!'Om the Carolina Slat e Belt of North Carolina Piedmont ( abs.): G e ol. Soc American S ec Ann Mtg. (Durham, North Carolina) Prog. p. 45.

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BULLETIN NO. 55 125 Kje ll es vigWaering, E. N. 1950 A new Silurian eurypterid from Florida : Jour. Paleontology, v. 24 no. 2, p. 229 231. Milton Charles 1965 (and Hurst, V J.) Sub s urfac e basem en t rock s of Georgia: Georgia Ceo!. Sur vey Bull. 76, 56 p. Mu e hlb erge r W. R., e t a!. 1 966 Geo c hronology of th e Midcontin ent r egion. United States; pt. 3, Southern area : Jour. Geophys. R ese arch, v. 71, p. 5 4 09 -5426 Ro ss, C. S. 1958 W elded tuff from d eep-well cores from Clinch County, Georgia: Am. Min eralogist 43, pp. 537545. Shapiro L. 1962 (and Branno c k W. W. ) Rapid analysis of s ilicate, carbon a te, and phosphate rock s : U.S. Ceo!. Surv e y Bull. 1144-A, 56 p. W esco tt M. R. 1966 L oss o r arg on from biotite in a thermal m e tam orp hism : Nature, v. 210, n o 5031, p. 83 84 Whittington, H. B. 195 3 A new Ordo vicia n tril ob it e f1'0m Florida : Breviora No. 17 6 p

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COPYRIGHT NOTICE [year of publication) Florida Geologica I Survey [source text] The F1orida Geological Survey holds all rights to the source text of the B1dletins, Annual Reports, I'!{ormation Cirt:ultln, Letiflets, Miscellanetn/S Snulies, Reports of Investigations, Special P11blications, and Maps and shall be considered the copyright holder for the text and images of these publications. The F101ida Geological Survey has made this publication available to the University ofF1orida, on behalf of the IMLS grant Linking F1orida's Natural Heritage, for purposes of digitization and Internet distribution. The F1orida Geological Survey reserves all rights to this publication. All uses, excluding those made under "fair use" provisions of U.S. Code, Title 17, Section 107 are restricted. Contact the F1orida Geological Survey (http://www.dep.state.fl.us/geol) for additional information and pennissions.

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STATE OF FLORIDA DEPARTMENT OF NATURAL RESOURCES Randolph Hodge s Ex ecutive Dir ec tor DIVISION OF INTERIOR RESOURCES Rob ert 0. V e rnon Dir e ctor BUREAU OF GEOLOGY Charle s W H endry, Jr Chi e f BULLETIN NO 55 IGNEOUS AND MET AM ORPHIC BASEMENT ROCKS OF FLORIDA By Charle s Milton Prepare d by the GEORGE WASHINGTO UN IVERSITY and th e U ITED STATES GEOLOGICAL SURVEY in coope r ation w ith th e BUREAU OF GEOLOGY FLORIDA DEPARTMENT OF NATURAL RESO URCES TALLAHASSEE 1 972

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,, DEPARTMENT OF NATURAL RESOURCES REUBIN O D. ASKEW Governo r RICHARD (DICK) STONE S ec r e tary of Stat e THOMAS D. O MALLEY Treasur e r FLOYD T. CHRIS TIAN Cnmmission e r of Education ROBERT L. SHEVIN Attorney G ene ral FRED 0. DICKINSON JR. Comptroll er DOYLE CONNER Commi sioner of Ag ri cu ltur e W. RANDOLPH HODGES Ex ecutive D irector ii

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LETTER OF TRANSMITTAL Bure au of Geo l ogy Tall a h assee O c tob e r 5, 1972 Honorabl e Reubin O'D. Ask e w Cha irm a n D epartment of Nat ur a l Resources Tallahass ee, Florida Dear Governo r Ask ew : The D epartment of Natural R e sources, Bureau of Geology, is publishing Bulletin No 55 e ntitl e d I gneous and Me tamorphic B asemen t Ro c k s of Florida" by C h a rles Milton U.S. G eo l og i ca l Sur vey This r eport d esc rib es the b ase m ent r ocks that h ave been p e n etra t e d by wells in th e State of Florida. These d ee psea t e d i g n eo u s and m e t amorphic rocks form th e structural backbone of th e p e nin s ul a and can b e inv a lu a bl e in the d e term ination of the struc tural hi story of the St a t e R es p ec tfull y yours, Charles W. H endry, Jr., Chi e f Bureau of Geology

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Complete d m a nu script receiv e d April 2 5 1972 Printed for th e Florida D e p artment of Natural R es ources Division of Inte rior R esources Bureau of G e ology by N e w sJournal Corpora tion Dayton a B e ach Florida Tallahassee 1972 iv

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ACKNOWLEDGMENTS This work was begun in 1949 with study of th e petrography of the cores and cutting from Florida, G eo r g ia and Alabama r eporte d on by Paul L. Applin ( 1951 ) in "Pre limin a r y R e po1t on Buri e d pre Rocks in Florida and Adjacent States (U S G ol. Survey Circular 91) This was the b as i c compendium of data th a n avai l a ble. For Florida, th e present r e port m ay b e conside r e d final or comprehensive summa r y report on th ese igneous rocks with inclu s i o n of much data accu mul a t d during the two d ecades following th e 19 5 1 circular. Mr. A pplin and the Burea u of G o l ogy have continue d their helpful inte r es t in thi s study, and furni s h e d part of th ese additiona l data. George V. Coh e gave va luabl e counse l and ass ist a n ce, and Miss Jean Berdan a l so of th e U. S. G eo lo gica l Surv ey contribute d paleonto logic-stratigrap hi c d a t a, b e sid es critically r ev i ew in g this r e port. I a m indebted to Dr. A. A. M eyerhoff, Publica tion Manager of th Ameri can Associa tion of P e trol e um G eo l og i sts for p e rmission to use mate r ial from a bri e f account of th es ro cks publis h e d in th e Bull e tin ( Milton and Grasty, 1969 ) A grant from th e Tational Sci e nce Founda tion provided facilities which w e r e us e d in th e pre p a ration of thi s r eport. ix

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Acknow l edgments. Previous st udi es CONTENTS Lo cation of w ells in Fl o rid a ( Map Figure lA) Li st of we lls in F l o rid a ( T a bl e l) ....... Introduction. ......... Petrograph y of Florida i g n e ous m etamorphi c ro c k s Dating o f F l o rid a and Georgia ign e ous m etamorphic rock s .. .. ... Che mical a n a ly ses of Florida i g n e ous m etamorphic ro cks ix X xi xii 2 8 9 D esc riptions of F l orid a b asement r oc k s . 1 2 Nassau County, St. Mar y's Riv e r Oil Co rp ., Hilliard Turpe ntin e No. 1 12 Co lumbia County, Humble Con e No. 1 Mad i son County, H unt, Gibson No. 1 Taylor Co unty Gulf, Bro oksScanlon No. 1 Taylor County, Humble, H odges No. 1 J e fferson Count y, Coasta l P e trol eum, Lars h No 1 Franklin County, C alifornia and Coastal P e trol eum, No. 2 State lease Jackson County, Humbl e, Tindel No. 1 ....... Walt o n C ounty, Pan America n, S e a ly No. 1 F l agler County, Humbl e, Campbe ll N o 1 .... Putnam County Sun W estbury No 1 Marion County, S u n Camp No. 1 1 3 19 20 2 1 26 3 1 3 1 3 7 3 8 4 4 49 Levy County, Humble Robin son No 1 ...... ....... ... 51 Vo lu sia County, Grace Drilling R e t ai l Lumbe r No. 1 Volusia County, Sun Powell No.1 .... Lake County, Lak e County Development, South L ak e No 2 .. Orange County, W a rre n T e rry No. 1 Indian County, Ame r a d a Mitch e ll No 1 St. Luci e County, Ame r a da, Cowl es M agaz in e No. 2 Osceo l a County, Humble, H ay m a n No. 1 Osceola County, Humble, Carroll No. 1 Okeechobee County, Ame r a da, Swen so n No 1 Okeechobee County, Ame rada, H arris -Holm es No.1 H i g hl ands County, Humble, Carl ton E s t a t e No.1 Hig hl ands County, Contin ental, C a rlt o n e t al. No. 1 ....... 55 57 6 4 66 66 76 76 81 84 84 92 ...... ... 101 ...... 10 9 Hardee County, Humble, K ee n No. 1 Hillsboro ugh Coun t y, Humbl e, J a m eso n No. 1 ......... .......... 11 3 R e f e r e n ces ................... ... 1 24 v

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Figure Columbia Count y 2 3 4 5 6 7 Madison County 8 Taylor County 9 10 11 12 1 3 Jeff e r son Count y 1 4 15 16a, b 17 Fra nklin County 18 19 20 J ackson County 2 1 a b 22 W a lt on County 2 3 24 Flag l e r Count y 25 2 6 a, b 27 Putna m County 28 29 3 0 3 1 Mari on County 32 L evy County ILLUSTRATIONS Page Humble, Co n e No. 1 352 0 -3529' top 7'. Bak e d s h a l e with andalusite (?). 3 3520' -3529', bottom 1 Alt e r e d diabas e 14 3543' -3555 top. Diabase. 15 4181' -4206 bottom. Amygdular basalt. 16 4 181 -4206' bottom. B asa lt -ca l ci t e (hydrothe rm a l?) contact. 17 4256' -4281 middle. Amy gdular basalt. 18 Hunt, Gibson No. 2 5200' -5210'. Diabase 19 Gulf ; Bro o k s Scanlon No 1 5512' -5517 bottom. Diabase-basalt 21 Humble, Hodges No. 1 6153)2'. Calcitiz e d basalt. 22 6155' Calcitized basaltdi a base. 23 6165W. Calcitized explosion breccia. 24 6216' -6219'. Unalte red diabase. 25 Coas t a l P e trol eum, Lars h No.1, 7789'-7 7 9 1 Diabase. ... ..... .............. 27 7791 -7795' top Bak e d s h a le(?). .. 28 7791 7795 bottom: Calcitized basalt. ... 29 7909 7911'. Sandstone, ordinary light and crossed nicols . 30 Californi a Co. and Coasta l P e troleum No 2 State Lse. 224-A 10325 -10326' Sands ton e w ith calcite and dickite (?). 32 10520' 105 3 0'. Calcitize d basalt ............ 33 10520' 105 3 0'. Baked shale. .. 34 Humble, Tinde l No. 1, 8881 -8891' top 5)4'. Siltston e .. 3 5 8881 '8891 bottom 1 '. Amygdular-quartz basalt, ordinary li ght and crosse d nicol s 3 6 Pan Ameri ca n Petroleum, J. R. Seal e y No. 1 11935' 119 4 0 Serici ti ze d rhyolite porphyry or ash. 37 11935 11940 '. Sericitized r hyolit e, or ash .... 3 8 Humble, Campbell No. 1 -4626 '. Volcani c agglomerate. 40 4638' 4639'. Volcani c agg lomerate-ash .... 41 4643 -4 6 44 '. Volcanic agglomerateash, ordinary li ght and cros se d ni c ols. .. 43 Sun W estbury No. 1 38 7 9' -388 1 Ash w ith fossil. .. 4 5 3885' -3887' .Pyrocla s ti c .. 46 3887' 389l'.Pyroclastic .. 47 3890' -389 2 .Pyro clastic. . 48 Sun, Camp No.1, 4574 -4584'. Arkos e with rhyo lit e . 50 Humble, Robin s on No. 1 4331 -43 3 6 Calcitized b asalt. 52 vi

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Figure 33 34 35 36 37 :38 .39 a, b 40 41 a, b -!2 43 -!4 45 4 6 47 a b -!8 a b 49 a, b 50 5 1 a, b 52 a b 53 a b 54 5 5 5 6 5 7 5 8 59 60 61 Vo lu sia County L a k e County Indi a n Riv e r C ounty St. Lu c i e County Osceo la County Ok eechobee County Hi ghlands County 4 3 4 4 -4356 Cal citized basalt. 4 3 58 -4359 Diabase .. G race Drilling R e tai l Lumbe r No. 1, Page 5 3 54 5424%'. Rhyolit e 56 Sun Powell Land No. 1 5922 -5925' W ea th e r e d ign e ou s rock. 58 595 4 5955 Diorite . 60 5954' -5955 Diorite with epidote 61 5955 -5956 Hornfe ls, ordina ry light and cross e d nicols 62 5957 % -5958 Hornfe l s 6 3 L a k e County Oil D e v el. South Lake No 2 6107' -6128'. "Granit e ", ordinary light and cros sed nicol s 65 Amerada P e tr o l e um Corp. Fondre n Mitch e ll o. 1 94 44' -9449' Basalt. 67 9 4-!4 94 4 9 Diaba s e . 68 9469 -947 4 Amygdu les in basalt. ... 69 9469 947 4 Amygdule in b asalt. 70 9484 9489 T. D. Qu a rt z itic basalt .......... 71 Ame r a da, Cowl es Magazine No. 2 12734'. Amy gdaloida l basa lt o rdinary light and cross e d ni c o l s 72 127 44'. Gr a nite, ordinary light and cross e d ni c ols ..... 7 4 12748 Diorite. ordin a ry light and crossed nicols 75 Humble, H a yman No. 1 8750' -875.3'. Rhyolite. 78 8765 8770'. Rhyolite, ordinary light and .n 8786 8787'. Rhyolit e, ordinary light and cros sed nicols ,80 Humble, J. R a y C a rroll No 1 80-!2 -8042%'. "Gra nit e", ordina1y li ght and c ros se d nichols ......... ....... 82-8 3 Amerada P e trol eum Corp., Mari e Sw e n s on N o 1 10760 -10770 Amygdular basalt. ..... 85 10760 -10770'. Bas a lt, non-amygdular 10760 -10770 Alt e r e d s h a le, and amygdular basalt ( 3 fra g m ents) .... ......... 87 10760 10770 .Ba s a lt. 88 10760 -10770 B a k e d sh a le. 89 10770 -10780 Amy gdular basalt. 90 108 3 0 108 4 0 T. D. Hydrothe rmal qua rtz, et c .. 91 Humble, C a rlton E sta t e No. 1 1269 4' 1 2699 .Ba s a lt .......... .. .... 9 3 vii

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Figure 62 6 3 6.f 65 66 67 68 69 7 0 71 72 7 3 7-1 Hardee County 75 a b 76 a b 77a, b 7 a b Hillsborou g h County 79 a, b 8 0 81 a b 82 8 3 8-1 85 Tabl es 12715' 1 2721'.Basalt. .... 12721 '1 2722 Ba sa lt Page ..... 95 ... 96 12721' 12722' B asa lt with ve i n l ets ......... 97 12771 -12775. Basalt.............. .. 98 12826' 1 28 67 Amygdu l a r basa lt w ith vein l e t s . ... 99 12826 12867'. Amy gdule in basa lt .. 100 Continental Oil, Carlton e t al. 12600 -12609 top. Altered basalti c as h with v ein l e ts. 10 2 12600 12609 bottom. Ba sa lt w i t h calc it e bands. 10 3 1261-f -12630 lower middle. Zon e d ch l orite amygdul e i n b asa lt 105 12641 -126 3 0 l owe r middle. Amygda l oida l basalt w ith ve inl e ts. ... 106 12629 bottom of h o l e. A m ygda l o id a l bas a lt w ith c h a l cedony (?). 107 1 2 614 '126 3 0 bottom. Amygda l o id a l basalt. 108 Humble, Keen No 1 1185 3 -11857 Basa l t with quartz ve in l et. 110 11867 -11877'. B asalt wi th quattz ch l or ite amygdul e, ordinary light and c r ossed nico l s. 111 11867'-11877 Amygdu la r breccia t e d basalt, ordinary light and c rosse d ni co ls. 112 11 932 11933' B asa l t ordimlly light an d c r ossed ni co l s .. 11 4 Humbl e, J ameson o. 1, 9995'10003'. Ar k osic sandstone, ord in ary light an d c rossed nico l s ....... .... ...... .... 115 1000 3' 10010. Grit o r arkose, ordina r y light and c ross e d nico l s 116 10010 '10019. Rhyolit e .... 117 10010 10 019 Rhyo lit e flow structure. 118 10025 Rhyolite..... 1 20 100-fO' -10043 Rhyolit e o r wel d e d tuff. 121 100-13' -1005 3'. Rhyolite. 122 10115' -10125 B asa l t i c rock. 1 23 TABLES Page 1 a Lo ca tion Map . . xi 1 F l o rid a wells drille d into Igneou s o r M e t amo rphi c ro c ks. xii 2 Isotope d ating of F lorida (and Georgia) roc k s. ................ 5 2a Age d e t e rmin ations-Ame rada Petro l e um Corp Cowles Magazin e o. 1 ...... 5 3 h e mic a l anal yses of Florida Igneous-Metamo rphic ro c k s 10 3a Fl o rid a i g n eous-metamorphic ro c k norms . ll v iii

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PRE\ 10 S ST DIE Th b as i c r e f e r n e work on th p etro log of th e ign o u s-m tamor phic rock b neath th e coa t a l plain of Florida eo rgia and l abama is b Applin ( 1951) who gave d a t a on 100 w lis drill d in th os three s t a t e Sixt y-fiv w II w e r e drill e d in Florida (of w h ich 3 w e r e r port d to have reached granit or diorite, t o hav e rea h d rh oliti or othe r val an ic rock, and 10 to have r ached b asalt or diabas ) ppl in s u g g e tld a Precambri an age f o r th e r anite-diorit ro k a -.: II a for th P idmont m tamorphic ro c k in eo rgi a and Alabama not far south of th e Fall Line This r eport in d icat es n o ages great e r th an Pal e ozoi and most of th m a r e much ounger. D a t a of fo ilifcrou M sozo i c tra t a under] in the Florida oastal plain have been ummarized b pplin and pplin ( 1965 1 7 ) on l y a f' well h a p e n etra t d i g n eo us rock ince pplin' s ( 1951 ) publica tion compa r ative l y littl e i added to p r iou s knO\ l edg of F l o r id a i g n e ous m e tamorphi c p e trology, and most of th e ir d i scu s i on i of pr v i o u I publ ish e d d a ta. Th y d escrib th coa t a l plain floor in north e rn and c entra l F l o rid a as a truncat d wface of i n eo u and s dim n t a r rock of "mo tl Pr cambri1n( ? ) and earl Paleozoi c" a e and i n n o rth e rn Fl o rid a a l a t e Tria i c ( ?)" i g n eo u s ro c ks. dditional data on l o r .ida w ells in p a rt unpub lished h av e b e n g iv e n t o u s I y P. L. pplin (writt n co rnrnun. 196 7 ) .Milton and Hurt ( 1965 ) de rib d a m pi es from 1 3 II whi c h wer drill d into Palcozoi or o l d e r g r anite and schis t and from anoth r 26 w ells whi c h were drill d b n a th th pl ain forma t ions int o vo l a ni c o r s dim nta r y rock mar rne t amorphos b y i g n o u s contact. Gra ty and Wil n ( 196 7 ) eli c u d th e Florida igneou rock w ith r r nee t o contine ntal drift. S r a l of th age d e t ermina ti o n g i n h e r e w e r e m a d forth ir tud Ba s ( 1969 ) r e p orted on th p tro g raph of nin e F l o rid a bas m ent rocks and gave thr ag d e t rmina ti o n s, c it d h e r in Table l. X

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/ / I / ... "' J I I I 8,4 83 T ab l e la. The number s a r e those d es i gnating th e well s in Table I and a r e the order in whic h the well s are dis c uss e d in the t ex t xi

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\Ve l/ Locality Fig 1 2 3 .s 6 Applin ( 1951) County No. 67 Nassau Columb i a 62 M a dison 8 2 Tayl o r 83 Ta y l or 5 I J e ff e rs o n F r a nk l in Tabl e 1. Florida Wells Drilled into Igneou s or Metamorphic Rocks Type o f R oc k Diabas e Diabase Diabase Dia base Bas a lt "gabbr o diabas e Di a base o r basalt D i abas e D e pth t o T o p o f I g neou s o r M eta m orphic R o c k (Jt ) 4 ,808 3,529 3,5(N -l, l 9 l 0 -l, JH3 -1, 218 -1.267 1 589 6 l 5 3 7,6 9 0 7,763 7 ,850 1 0.-160 1 'hickness Of Igneou s o r i\l e ta M orphic Rock P e n e t r a t e d (ft) 16 33 l 1 2 3 3 3 9 7 9 lOJ 10 9 10 1 0 T o t a l D epth o f B o tt o m Rock W e ll ({t) -1, 82-l 5,385 5,. 51 7 6 ,254 7,913 10, .566 ( Driller) l0,507 (elec. l o g) Diabase Black s h a l e Pal eozo i c b l ack s h a l e Dia base o r basalt D iabase S a nd s t o n e Diabase R e m a rks Intrudes lower P a leozoi c blac k s h a l e S a m p les l a b e l e d -1,1814 ,206 ft and 1 2 3 1 --!,2Rl ft a r e amygdal o i dal basal t. Blac k shal e o v e r l y in g dia base a t 3,.529 n conta in s abunda nt sercitized a nd a l u site (?) (Fig. 2a) Sampl s liib e l e d .5, 200.5,201 ft a r e h ydrothe rm ally a l t e r e d diabase. Alt e red diabase o r b asalt. Uppe r 1 2 ft i s bas alt; lowe r 89 ft i s dia base gabbro (Applin 195 1 ) Upper 10 ft o f basal t hig hl y cal ci ti c and stro n g l y brecc iat e d An a l y s i s 5 : diabase, 6,162 ft. Anal y sis 6 : d iabase, 6 2 1 6 6 2 1 9 ft California C o and Coastal P etro l eum C o l\:o 2 St a t e Lease 22IA D a t a from i'>. L Appli;, (writte n commun. 1967) Loca-t i o n : L a t. 29-l7'03"N l o n g 8-!0 22'.51"W, a b out 1 3 mi o ff s h o r e fro m C arra b el l e, Flo rida

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Table.,L (Continued) Well Locality Fig. l 8 9 10 11 1 2 1 3 1-l 15 16 Appli n ( 1951) County N o 5 3 Jackson Walton 19 F lagler 25 Putnam 2 3 Marion 60 Levy 26 Vol u sia 7 Vol u s i a 5 Lake Type of R oc k Porphyritic h ornblende Bas alt (Applin 1951) Strongl y a l t ered porph yritic rhy o lit e Bas altic and rhy olitic tuff Volcanic as h Rhy o li t e o r rhyolitic ash Diabas e "Rh y olitic( ? ) v olcanic roc k (Applin, 1951) M e t abas a l t A l a skite" or "granite Depth to Top of Ig n eous or Meta nwrphic R oc k (ft) 8,890 8,970 1UJ10 4 ,588 3,873 -1, 61.3 -1,3 1 7 5,-103 5 ,910 5,951.5,952 6,103 Thickness Qf Igneous o r M e ta j\1.orphic Rock Penetrate d (.ft ) -12 13 38 -!4 19 22 60 21 12 26 Total Depth of Bottom Rock Well (ft) 9 ,245 11,948 -!,632 3,982 -1, 6 3 7 4,609 5 ,424 5 9.58 6 ,129 Devonian s ilt s t o n e Rhyolit e ash or prorphyry V olcanic agglomerate o f rhyolitic a n d b asalti c d ebris A s h o r rhy olite As h o r rhyolite L o w e r P a l eozoi c quartzitt and s h a l e Rhyolite M e t abasalt, e t c "Alaskite" (II. L. T omlinson, unpub. dat a ) "Granite" (Appl in 1 9.51) R e m a rks Basal t i s amygdal oidal. P a n American N o 1 J. E. Sealey. D ata from Applin (written commun., 1967) cite d i n l etter from H. T. V i o l ette t o P. L. Appli n june 3, HJ60. An.-1lysi s 8: volcanic a g g l o merate, 4,624 3/-l --1,626 ft. F ossils ( ? ) An a lysi s 9, ash or rh y olite 3,879 -3,881 ft. Top of i g neous rock i s clayey, b ottom fresh diabase. "No cores take n i n volcani c rock. (Appli n H J51 ) cuttings (.5,-!2-l 1 / 2 T .D.) a r e fresh r hyo l i t e. A lso alte r e d cal care o u s shale (?) V o l canic rock alte r e d t o clay Analysis 7: m e t a basalt, 5,919-.5,922 ft. Age more than 480 m. y. M eta-arkose ( ? ) "not studied p etrographically" (Applin, 1951 ) (Fig 2b)

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Tab l e 1. (Cont-inu e d ) D epth t o T hi cknes s T o p o f Of I g n eous W e ll Applin Type of Igneous o r o r lvl e t a -T otal L o cality ( 1951) Co u nty Rock M etaM orphic D epth of B ottom Hock R e m.ark s Fig. 1 N o ntorphic H ock W e ll (ft ) Hock P e n etrate d ([1) (ft ) 1 7 Orange "Granite'' 6,5.50 fi,5HH "Granite'' \Varne r P e t r ol< urn C o N o Georg e T e rry. Data fr o m Applin (writt<'n commun., 1067) W ell (il o f Appl in and Applin (196. 5). c S\V\4 SE\4. Sec. 21, T23 S H 3 1 E samples availa bl e. 1 8 [n d i c l n A 7H 9 188 Diabase Ame rada Petrol eu m Corp. N o 1 Ri v e r Frondre n Mitchell. Data fr o m Applin (written commun., 1067) >< Sec. 2H, T-3 1 S ::: 19 St. Lucie Basalt 1:2,72. 5 2 3 "'Diorite .. P etro l e u m Corp N o 2 G ranite Cowl es M a gazinP \V el! 68A o f D i o rit e A p plin a n d A pplin Anal -ys i s 2 : b asalt, 1 2 7 3-1 ft, age 8H. 3 2.2 m.y. ( Fi g 2d) Analysi s 3 : 0g r anite,"l 2 7.J.JJ't age226:!:(:;m y. (Fig 3a). Anal ys i s .J: "'di o r -it e,'' ft, ag<' 308. 5 m.y. (.5 3 0 + m .y Ba s s 196H) {Fig 3 b ) 20 2-1 Osceol a Hh y o lit e 8 7-10 .58 8 ,708 Hhyo lit e Age 1 7 3 m y 21 6 Osceol a "Granite" 8 0 3 5 l.J 8, 0-19 ''Granite ., Analysi s 1: g r anite o r arkose, Arko s e (?) 8 0.35 7 8,0-12 (Applin, 1951) ll, 0 3 l-8,0.J2 ft, age 530 Ill.)'. Arkose(?) (Bass, 1 969) ( Fig. 2 c) 22 Okeech o b e e "Volcanic'' 10,7.50 8H 10,838 Ba s alt Ame rada P e trol eum Corp. No. 1 rocks Marie Swe n s on Data from Ap plin (writte n c:ommun., 1 967). Wt'i l 60 o f Applin and Appli n S l'c .. 5 T.36S. H 3 .JE.

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Table l. (Continued) Depth to Thickness Top of Of Igneous Well Applin Type of Igneous or or 1\tletaTotal Localjty (1951) County Rock Meta-Morphic Depth of Bottom Rock Remarks Fig. 1 No. morphic Rock Well (ft) Rock Penetrated (ft) (ft) 2 3 Okeechobee Rhyolite 9,682 1.58 9,840 Sun Oil Co.-Ame rada Pet rol e -porphyry Ul11 Corp. No. 1 Harris Holm