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 Front Cover
 Front Matter
 Title Page
 Letter of transmittal
 Table of Contents
 Administrative report
 Statistics on mineral industries...
 The pebble phosphates of Flori...
 The natural resources of an area...
 Soil survey of Bradford County
 Soil survey of Pinellas County
 General index
 Back Matter
 Back Cover


FGS



Annual report
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Permanent Link: http://ufdc.ufl.edu/UF00000001/00007
 Material Information
Title: Annual report
Portion of title: Annual report of the Florida State Geological Survey
Physical Description: v. : ill. (some folded), maps (some folded, some in pockets) ; 23 cm.
Language: English
Creator: Florida Geological Survey
Publisher: Capital Pub. Co., State printer,
Capital Pub. Co., State printer
Place of Publication: Tallahassee, Fla
Publication Date: 1913-1914
Copyright Date: 1930
Frequency: annual
regular
 Subjects
Subjects / Keywords: Geology -- Periodicals -- Florida   ( lcsh )
Genre: Periodicals   ( lcsh )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
serial   ( sobekcm )
 Notes
Additional Physical Form: Also issued online.
Dates or Sequential Designation: 1st (1907/08)-24th (1930-1932).
Numbering Peculiarities: Some parts of the reports also issued separately.
Numbering Peculiarities: Report year ends June 30.
Numbering Peculiarities: Tenth to Eleventh, Twenty-first to Twenty-second, and Twenty-third to Twenty-fourth annual reports, 1916/18, 1928/30-1930/32 are issued in combined numbers.
Statement of Responsibility: Florida State Geological Survey.
 Record Information
Source Institution: 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 - AAA0384
ltuf - AAA7300
oclc - 01332249
alephbibnum - 000006073
oclc - 1332249
lccn - gs 08000397
System ID: UF00000001:00007
 Related Items
Succeeded by: Biennial report to State Board of Conservation

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Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Front Matter
        Front Matter 1
        Front Matter 2
        Front Matter 3
        Front Matter 4
    Title Page
        Page 1
    Letter of transmittal
        Page 2
    Table of Contents
        Page 3
        Page 4
    Administrative report
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
    Statistics on mineral industries of Florida
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
    The pebble phosphates of Florida
        Page 25
        Page 26
        Page 27
        Page 28
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    The natural resources of an area in Central Florida, including a part of Marion, Levy, Citrus and Sumter counties
        Page 117
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    Soil survey of Bradford County
        Page 253
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    Soil survey of Pinellas County
        Page 293
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    General index
        Page 333
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    Back Matter
        Page 343
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    Back Cover
        Page 347
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Full Text


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- ,:i :: UNIVERSITY OF MICHIGAN


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Original from
UNIVERSITY OF MICHIGAN










FLORIDA(STATE)GEOLOGICAL SURVEY
E. H. SELLARDS, Ph. D., State Geologist

















SEVENTH ANNUAL REPORT

















PUBLISHED Fox
THE STATE GEOLOGICAL SURVEY
TALLAHASSEE, 1915


Original from
UNIVERSITY OF MICHIGAN


Ic ~i























LETTER OF TRANSMITTAL.


To His Excellency, Hon. Park Trammell, Governor of Florida.
SIR:-In accordance with the Survey law I submit herewith
my Seventh Annual Report as State Geologist of Florida. This
report contains the statement of expenditures by the Survey for the
year ending June 30, 1914, together with those investigations by
the Survey that have progressed far enough to be available for
publication.
Permit me to express in this connection my appreciation of the
interest you have shown in the work of the State Geological Survey.
Very respectfully,
E H. SELLARDS,
State Geologist.















IJHE E.O. PAINTER PRINTING CODE LAND. FL;N 10456
Original from
.. O :UNIVERSITY OF MICHIGAN












CONTENTS.
PAGE
Administrative Report ---------------------------------------- 5
Statistics on Mineral Industries of Florida, by E. H. Sellards------------- 13
The Pebble Phosphates of Florida, by E. H. Sellards------------------- 25
The Natural resources of an area in Central Florida, including a part
of Marion, Levy, Citrus and Sumter counties, by E. H. Sellards,
Roland M. Harper, Charles N. Mooney, W. J. Latimer, Herman Gun-
ter and Emil Gunter.....--------. -------.....--------------- --. 117
Soil Survey of Bradford County, by W. C. Byers, Arthur E. Taylor, J. B.
R. Dickey and 1N. M. Kirk- --------- ------------------- 253
Soil Survey of Pinellas County, by Grove B. Jones and T. M. Morrison... 293
ILLUSTRATIONS.
Fig. I. Map to show the location of phosphate deposits in Florida------ 30
Fig. 2. View to show overburden of the land pebble phosphate--------- 42
Fig. 3. Mining River pebble phosphate ----- ------------------ 44
Fig. 4. Diagrammatic sketch to show the structure of Florida------------ 53
Fig. 5. Diagrammatic sketch to show conditions under which the land
pebble phosphates were accumulated------------- ------- 59
Fig. 6. Unconformity in the phosphate bed------------------------- 62
Fig. 7. Top view of land tortoise------------------------ 70
Fig. 8. Part of lower jaw of a gavial ----------------- ------ 74
Fig. 9. Side view of land tortoise------------------------------- 75
Fig, 1o. Jaw and teeth of Chlamytherium-- ------.....-------------- 80
Fig. i Ostrea from the Bone Valley formation.-----.. ------.---.. --- 83
Fig. 12. Tooth of the elephant-----.. ------------------------ 85
Fig. 13. Alum Bluff on the Apalachicola River-...---------..------.... 87
Fig. 14. View in Pit of Pembroke mine----.----....---------...---..-- 89
'- Fig. 15. Mining Phosphate Rock by Hydraulic Method--------------- 89
Fig. 16. Phosphate Washer ---------------------------.----------. 89
Fig. 17. Pit of Palmetto Phosphate Company------------------------ 91
Fig. 18. Pit of the Pierce Phosphate Company. --------------------- 91
Fig. 19. Plant of the Pierce Phosphate Company. ----------------- 91
Fig. 20. Sample of Phosphatic Marl from Black Creek--.--.--.. ----..--. 93
Fig. 21. Sample from Phosphate Bed----------- ----------------- 93
Fig. 22. Phosphate Pebbles washed from the bed rock------------------ 95
Fig. 23. Phosphate Pebbles from the phosphate bed------------------- 95
Fig. 24. Phosphate pebbles from the Bed Rock----------------------- 97
Fig. 25. Phosphate pebbles from the Phosphate Bed--------------- ---- 97
Fig. 26. Shark's teeth .---.....--.--.....-------------------.. 99
Fig. 27. Phosphate Pebble ---------- ---------------------------- 99
Fig. 28. Shark's Teeth .......------. ------ -------....-----------.. 99
Fig. 29. Skull of Gavial, top side--------------------------------- Io
Fig. 3o. Skull of Gavial. lower side--------------------...--------- 1 rot
Fig. 31. Snout of the Cetacean ----- -------------------------- 0o3
Fig. 32. Part of the skull of a Cetacean ---- ---------------------103
Fig. 33. Vertebrae of a Cetacean ------------------ ------5----- o
Fig. 34. Tooth of a Mastiodn -.-I_-, c.irjrLaltirila___- Io05
f : 3 UNIVERSITY OF MICHIGAN

285164








4 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

Fig. 35. Tooth of a Mastodon--- ------------- ----------
Fig. 36. Tusk of Mastodon------------ ------------------------
Fig. 37. Lower jaw of Rhinoceros --------
Fig. 38. Tip of jaw of Rhinoceros----- --------------- ----
Fig. 39. Base of Lower Jaw of Rhinoceros--------------------------
Fig. 40. Equus, first or second right upper molar---...------. -----.. --
Fig. 41. Equus, second left lower premolar----- ---- ------------
Fig. 42. Equus, first left upper molar--------------------------------
Fig. 43. Equus, left lower molar or premolar ------------------
Fig. 44. Hipparion ------------------ ----------- --
Fig. 45. Mammut americanum ----------------------------------
Fig. 46. Elephas columbi var. ---------
Fig. 47. Equus, lower tooth ...... ------------ -------
Fig. 48. Chlamytherium septentrionalis, plates and tooth --------. ----
Fig. 49. Chlamytherium septentrionalis, lower jaw from above -------
Fig. 50. Capybara-like rodent teeth -----------------------
Fig. 51. Chlamytherium septentrionalis, right lower jaw, exterior view.--
Fig. 52. Chlamytherium septentrionalis, right lower jaw, interior view--
Fig. 53. Sketch map showing the location of the Ocala area......------
Fig. 54. Lime pit near Ocala-----------..... -----..---- --........
Fig. 55. Mining phosphate rock by floating dredge near Dunnellon--....
Fig. 56. Silver Springs in Marion County.-----------------
Fig. 57. Small prairie surrounded by pine woods, near Wildwood------
Fig. 58. Prairie Vegetation in Lake Tsala Apopka------- -------
Fig. 59. Scrub thicket on peninsula of Lake Tsala Apopka_---------
Fig. 6o. Open scrub about five miles west of Inverness--- ---------.
Fig. 61. Burned area in scrub, one and one-half miles northeast of Silver
Springs--- -------------
Fig. 62. Interior of dense scrub on a peninsula of Lake Tsala Apopka .-.
Fig. 63. Flatwoods west of Wildwood---- --------- --------
Fig. 64. High pine land with scattered oaks, west of Inverness-..-----...
Fig. 65. Red oak woods near Ocala......------. --------- ----........
Fig. 66. Sandy hammock, about six miles west of Ocala----.... ----.....
Fig. 67. Hammock, about one mile southeast of Ocala-- ---.----..... .-
Fig. 68. Swampy spot in low calcareous hammock, near Wildwood.---..
Fig. 69. Swamp a few miles west of Wildwood----------------
Fig. 70. Short-leaf pine and cabbage palmetto bottoms.......--------....
Fig. 71. Sketch map showing the location of Bradford County------
Fig. 72. Sketch map showing the location of soil surveys in Florida ___--
Fig. 73. Water and grass pond east of Tarpon Springs _____---------
Fig. 74. Orange grove on Norfolk fine sand----------- ----------
Fig. 75. Change from Portsmouth fine sand to Norfolk fine sand-----
Fig. 76. Characteristic topography and growth on Norfolk fine sand-----
Fig. 77. Swamp phase of Portsmouth fine sand-------------------
Fig. 78. Characteristic growth on Leon fine sand------------- ----
Fig. 79. Character of vegetation on Parkwood fine sandy loam------------
Fig. 80. Tidal marsh between Ozona and Sutherland-----------------

MAPS FACING
Map showing the distribution of the native vegetation ----- --------
Soil map of the Ocala Area ..........--------------------- ---.
Soil map of BrddTogrit 'j ...y---------- _tgiRal asJJr01-
Soil' ma of Pmeniras ..nt.----------UNlVE S.--------


1o7
107
107
log
109
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ITI
III
III
III
III
113
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115
115

116
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122
149
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155

155
157
157
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161
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163
163
163
255
295
309
309
311
311
313
315
315
316

PAGE
134
251
291
332












ADMINISTRATIVE REPORT.


E. H. SELLARDS, STATE GEOLOGIST.



PUBLICATIONS ISSUED BY THE STATE GEOLOGICAL SURVEY.

The following is a list of the publications issued by the State
Geological Survey since its organization:

ANNUAL REPORTS.

First Annual Report, 1908, 114 pp., 6 pls.
This report contains: (i) a sketch of the geology of Florida; (2) a
chapter on mineral industries, including phosphate, kaolin or ball clay, brick-
making clays, fuller's earth, peat, lime and cement and road-making materials;
(3) a bibliography of publications on Florida geology, with a review of the
more important papers published previous to the organization of the present
Geological Survey.

Second Annual Report, 1909, 299 pp., 19 pls., 5 text figures, and
one map.
This report contains:' (I) a preliminary report on the geology of Florida,
with special reference to stratigraphy, including a topographic and geologic
map of Florida, prepared in co-operation with the United States Geological
Survey; (2) mineral industries; (3) the fuller's earth deposits of Gadsden
County, with notes on similar deposits found elsewhere in the State.

Third Annual Report, 1910, 397 pp., 28 pls., 30 text figures.
This report contains: (i) a preliminary paper on the Florida phosphate
deposits; (2) some Florida lakes and lake basins; (3) the artesian water supply
of eastern Florida; (4) a preliminary report on the Florida peat deposits.

Fourth Annual Report, 1912, 175 pp., 16 pls., 15 text figures,
one map.
This report contains! (i) the soils and other surface residual materials
of Florida, their origin, character and the formations from which derived;
(2) the water supply of west-central and west Florida; (3) the production of
phosphate rock in Florida during I91o and 1911.

Fifth Annual Report, 1913, 306 pp., 14 pls., 17 text figures,
two maps.( C Ori cinal from
:: ,:: :, ,) UNIVERSITY OF MICHIGAN







FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.


This report contains: (i) Origin of the hard rock phosphates of Flor-
ida; (2) list of elevations in Florida; (3) artesian water supply of eastern
and southern Florida; (4). production of phosphate in Florida during 1912;
(5) statistics on public roads in Florida.

Sixth Annual Report, 1914, 451 pp., 90 figures, one map.
This report contains: (I) mineral industries and resources of Florida;
(2) some Florida lakes and lalke basins; (3) the relation between the Dunnellon
formation and the Alachua clays of Florida; (4) geography and vegetation of
northern Florida.

Seventh Annual Report (this volume).

BULLETINS.

Bulletin No. I. The Underground Water Supply of Central
Florida, 1908, 103 pp., 6 pls., 6 text figures.
This report contains: (i) Underground water; general discussion; (2) the
underground water of central Florida, deep and shallow wells, spring and arte-
sian prospects; (3) effects of underground solution, cavities, sinkholes, disap-
pearing streams and solution basins; (4) drainage of lakes, ponds and swamp
lands and disposal of sewage by bored wells; (5) water analyses and tables
giving general water resources, public water supplies, spring and well records.

Bulletin No. 2. Roads and Road Materials of Florida, 1911,
31 PP., 4 pls.
This bulletin contains: (i) An account of the road building materials of
Florida; (2) a statistical table showing the amount of improved roads built by
the counties of the State to the close of 19io.

PRESS BULLETINS.

In addition to the regular reports of the Survey as listed above,
press Bulletins have been issued as follows:
No. I. The Extinct Land Animals of Florida, February 6,
1913.
No. 2. Production of Phosphate Rock in Florida during 1912,
March 12, 1913.
No. 3. Summary of Papers Presented by the State Geologist
at the Atlanta Meeting of the American Association for the Ad-
vancement of Science. December 31, 1913.
No. 4. The Utility of Well Records, January 15, 1914.
No. 5. Production of Phosphate Rock in Florida during 1913,
May 20, 1914- -., I R Or iginal from
Lb :!"' "' > O UNIVERSITY OF MICHIGAN






ADMINISTRATIVE REPORT


No. 6. The Value to Science of the Fossil Animal Remains
Found Imbedded in the Earth, January, 1915.
No. 7. Report on Clay Tests for Paving Brick, April, 1915.
Press Bulletin-No. 6 is included herewith. Press Bulletin No. 7
is included under Mineral Industries. The other press bulletins, with
the exception of No. 3, are included in the preceding reports of the
Survey.
DISTRIBUTION OF REPORTS.
The reports issued by the State Geological Survey are distrib-
uted upon request, and may be obtained without cost by addressing
the State Geologist, Tallahassee, Florida. Requests by those living
outside of the State of Florida should be accompanied by postage,
or if desired the reports will be sent express collect.

THE VALUE TO SCIENCE OF THE FOSSIL ANIMAL RE-
MAINS FOUND IMBEDDED IN THE EARTH.*
The value to science of the fossil animal remains found imbedded
in the earth is sometimes not fully appreciated. To the geologist,
fossils are not curios or objects of temporary interest, but are work-
ing tools, since it is chiefly by them that the age of the deposits in
which they occur is determined. Each formation and geologic time
division is characterized more or less definitely by the animals and
plants that were then living. In passing from one formation to an-
other a change is observed in the animal and plant life, which among
other things determines the limits of the formation. In some of the
European countries the value of fossils to science is much more fully
recognized than in America, and it is required by law that fossils
when found be preserved. It is very much to be hoped that in this
country the true value of fossils may be more fully appreciated, and
that all that are found may be cared for. This is especially to be de-
sired in Florida where the rapid developments that are now in prog-
ress result in extensive excavations, not only in connection with min-
ing operations, but also in connection with the drainage of lands, har-
bor and river dredging, and other general improvements. These op-
erations are bringing to light many animal remains that have been
imbedded in the earth for ages, and it certainly would be exceeding-
ly unfortunate if these were allowed to be destroyed.

*First published as Press Bulletin No. 6. January, 106 i.inal from
: : UNIVERSITY OF MICHIGAN







8 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

Some progress has been made in the study of the extinct life of
Florida and already we have record of the presence in the State dur-
ing earlier times of many animals which are now either entirely
extinct or are found only in remote parts of the earth. Among the
land animals that formerly lived in Florida the following may be
mentioned as of special interest. The list here given, however, is by
no means complete.
THE ELEPHANTS.
In former times the elephants, now found native only in Africa and Asia,
were present in North America, and extended their range into Florida, their
remains having been found at many localities throughout the State. The parts
of the skeleton most commonly found are isolated bones, grinding teeth and
tusks, the large size of which invariably attracts attention. The elephant found
in Florida is not the mammoth of the northern states, but is the Columbian ele-
phant, Elephas columbi. Some of the teeth, however, closely resemble those of
the Imperial elephant which was formerly abundant in the western part of the
United States and it is possible that both species were present in Florida. In
addition to the true elephants, there were present in Florida, as shown by their
fossil remains, at least two species of the mastodons or primitive elephants. One
of these, the American mastodon, known as Mammut americanum, was contem-
poraneous with the elephant, or possibly endured on this continent longer than
did the elephant. The other mastodons of Florida, of which there may be more
than one species, existed at a time previous to the appearance either of the true
elephants or of the American mastodon, and are found only in deposits older
than those in which is imbedded the remains of the elephant.

THE HORSES.
Florida was evidently the home, through long geologic periods, of various
species of the horse family. In the comparatively late formations is found re-
mains of the true horse, Equus, which, however, differs from the domestic horse,
which was re-introduced from Europe after the horses native to America had be-
come extinct. In the somewhat older formations are found earlier, smaller and
more primitive horses which were evidently the associates of the early masto-
dons, being imbedded in the same deposits. These early members of the horse
family are placed under the genus Hipparion.

THE RHINOCEROSES.
It is of much interest to find that the rhinoceroses at one time made up an
important element in the land fauna of Florida, being found in the Pliocene de-
posits of central Florida in association with those of the early horse and masto-
don, the remains of all of which have been brought to light in connection with
phosphate mining. Two species of rhinoceroses are recognized, one of which
included stocky and heavy built animals, while the other kind was more nearly
of the proportions of the modern rhinoceroses of Africa and Asia. Neither,
however, were identical with any of the species now living.
S ') Original from
... :! O UNIVERSITYOF MICHIGAN







ADMINISTRATIVE REPORT


CAMELS, LLAMAS AND TAPIRS.
The camels, another group of animals now found only in Asia and Africa,
and their relatives the llamas, now confined to South America, were formerly
present in the United States and extended their range into Florida. The tapirs,
likewise, were formerly native to Florida. The camel remains are found in as-
sociation with those of the rhinoceros and pertain to species not now in exist-
ence. The tapir and llama remains are found for the most part in comparatively
recent geologic deposits and represent species closely related to, if not identical
with those now living.

SLOTHS AND ARMADILLOS.
Among other animals formerly present in Florida should be mentioned
members of the sloth tribe, the modern representatives of which are now found
only in South America. With the sloths is associated an armadillo-like animal,
much larger, however, than the modern armadillos. The sloths found fossil in
Florida were also larger than those now living. The Glyptodons, now entirely
extinct, is another group closely related to the armadillos, which are also repre-
sented by fossil remains in Florida.

While some progress has been made, it is evident that much yet
remains to be learned of the animals of the past in Florida. It is
sometimes supposed that only the larger animals are of interest.
This is not true since for geologic purposes the small animals are
equally as important as the large. Fragmentary remains are also
frequently of value, since the presence of a single tooth or bone may
prove the presence of a species in a formation. Vertebrate and in-
vertebrate, land and marine animals are all of value in the study of
the geology of the State.
Will you not lend your aid to the work of the State Geological
Survey by preserving the fossils that are found in your neighbor-
hood or in connection with your own work and submitting them to
the State Geologist?
Valuable assistance has already been rendered the Survey in this
w-ay by the various mining companies and by individuals, all of
which help is very much appreciated.









Q ) Oricginal from
... :! O UNIVERSITY OF MICHIGAN







1O FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

EXPENDITURES OF THE GEOLOGICAL SURVEY FOR
THE YEAR ENDING JUNE 30, 1914.

The total appropriation for the State Geological Survey is $7,500
per annum. No part of this fund is handled direct by the State
Geologist, as all survey accounts are paid upon warrants drawn up-
on the Treasurer by the Comptroller as per itemized statements ap-
proved by the Governor. The original of all bills and the itemized
statements of all expense accounts are on file in the office of the
Comptroller. Duplicate copies of the same are on file in the office of
the State Geologist. The warrants when paid are on file in the
office of the State Treasurer.
List of warrants issued during the year ending June 30, 1914:

JULY, 1913.
Alex Walton, janitor service--------- ---------------------$ Io.oo
Dan Allen, drayage------------ ----------------------------- 4.50
D. R. Cox Furniture Company, supplies ------------------------ 8.25

AUGUST, 1913.
E. H. Sellards, State Geologist, expenses, August, 1913----------- 49.04
Alex McDougall, postage--------------------------------- 25.00
E. H. J. Lorenz, maps ------------------------------ --- 80.00
Alex Walton, janitor services--------- ------------------- 10.00

SEPTEMBER, 1913.
E. H. Sellards, State Geologist, salary for quarter ending September
30, 1913 ---------------------------------------------------- 625.00
E. H. Sellards, State Geologist, expenses, September, 1913--------- 38.40
Herman Gunter, Assistant, salary for quarter ending September
30, 1913 -----------------------------------------------------37500
Laura Smith, stenographic services---------------------- ----- 75.00
F. C. Gilmore, carpenter work------------------------------ 2.00
Alex Walton, janitor services.---...------------.-----------.... o.oo

OCTOBER, 1913.
A. Hoen & Company, maps of Florida--------------------------- 37.00
Alex McDougall, postage-- ---------------------------- 25.00
Dan Allen, freight and drayage------------------------------- 4.94
Alex Walton, janitor services --------------------------------- .00
Herman Gunter, assistant, expenses. October, 1913 ------------ 22.40
E. H. Sellards, State Geologist, expenses, October, 1913----------- 51.13

NOVEMBER, 1913.
E. H. Sellards, State Geologist, expenses, November, 1913--------- 101.58
Herman Gunter, assistant, expenses. November, 1913-------------- 64.85
Southern Expres ,ComnI~i. l---------j.crinLrjaoc------- 1.60
j- d- ^ UNIVERSITY OF MICHIGAN








ADMINISTRATIVE REPORT II

Dan Allen,- freight and drayage ------------------------------- 2.32
Alex Walton, janitor services--------------------------------- 10.oo
Alex McDougall, postage...-------------------------------- 125.00
The Lettershop ---------------------- ----------------- -- 2.25

DECEMBER, 1913.
E. H. Sellards, State Geologist, salary for quarter ending December
31, 1913 -------------------------------------------- 625.00
Herman Gunter, assistant, salary for quarter ending December
31, 1913 ----------------------------------------------------- 375.00
Laura Smith, stenographic services--------------------------- 75.00
Alex Walton, janitor services------------....---------------- -- 1o.oo
Collins Printing Company, printing----------------------------2.50
Southern Express Company ------------------------------ 5.36
Alex McDougall, .postage------------ ----------------------- 25.00

JANUARY, 1914.
E. H. Sellards, State Geologist, expenses ---------------------- 14.95
Herman Gunter, Assistant, expenses, January, 1914---------------- 28.75
Alex McDougall, postage -------------------------------------- 2.75
Southern Express Company ----------------------------- 2.71
A. Hoen & Co. ------------------------------------- ----- 20.00
H. & W. B. Drew Company-------------- ------------------ 15.47
The Letter Shop ------------------------------------- -- 5.25
Engineering & Mining Journal, subscription---------------------- 5.00
Economic Geology Publishing Co., subscription------------------- 3.00
American Journal of Science, subscription----------- ---------- 6.00
T. J. Appleyard, State Printer----------------------------- 71.00
Dan Allen, freight and drayage------------------------------ 7.54

FEBRUARY, 1914.
E. H. Sellards, State Geologist, expenses---------- -------- 68.55
Herman Gunter, Assistant, expenses------------------ ---------- 41.05
Alex McDougall, postage----------------------------------- 50.00
Ware Bros., Subscription American Fertilizer------------------- 5.00
Alex Walton, janitor services -------------------------------- 2o.oo

MARCH, 1914.
E. H. Sellards, State Geologist, salary for quarter ending March
31, 1914 ----------------------------------------- ---- 625.00
Herman Gunter, Assistant, salary for quarter ending March 31, 1914 375.00
Laura Smith, stenographic services ---------------------------- 75.00
Ed Lomas, janitor services ----------------------------------- o.oo
Alex McDougall, postage--------------------------------- 25.00
J. K. Small, publications--.------..... ------.---. ----........6.50
G. E. Stechert & Co., publications------------------------- 7.-50
D. R. Cox Furniture Company, supplies----------------------- 18.40
American Peat Society, publications--------------------------- 3.00
Southern Express Company ------_----------------------- 3.25
MacMillan Company, publications ---- ---------------- 12.75
R. M. Harper, salar T~.~f irl~.p1 $iio.oo; expensQri $. fi 2.~oL I. 143.60
,- .' .,: ... ,,f UNIVERSITYOF MICHIGAN







12 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

APRIL, 1914.
R. M. Harper, salary, April, 19r4--------------------------------- 125.00
Southern Express Company -----------------........ ---------. 2.86
McGraw-Hill Book Co., publications_--__----- ---------------- 4.oo
Dan Allen. freight and drayage--------------------- ---------- 427
Standard Supply Company, supplies-------------------------- 9.97
University of Chicago Press, publications---...---.---------...... 245
Wi B. Scott, publications---------------.------------ 19.43
Dodd, Mead & Co., publications ------------- ------------- 1.83
D. R. Cox Furniture Company, supplies---.---------------...- 78-40

MAY, 1914.
E. H. Sellards, State Geologist, expenses, March, April and May,
1914 ------------------------------------------------------- 128.93
Herman Gunter, Assistant, expenses, May, 1914------------------ -- 36.1i
R. AL Harper, salary, May, 1914, $125.0o; expenses, $16.62.------. 141.62
T. J. Appleyard, State Printer----- -------------------------- 15.00
University of Chicago Press, subscription-------------------- 3.60
Dan Allen, freight and drayage------------------------------- 10.31
Andrus & Church, supplies......------....-------......------ 22.30
Southern Express Company- -------------------------------------- 20
David S. Woodrow, agt. Phosphate Industry.----..... -----.. --.- 6.00
Alex McDougall, postage ------------------------------------- 25.00
F. C. Gilmore, supplies ------------ ---------------------- 4.75

JUNE, 1914.
E. H. Sellards, State Geologist, salary for quarter ending June 3o,
1914 ---------------------------------------------- 625.oo
Herman Gunter, Assistant, salary for quarter ending June 30, 1914 375.00
R. M. Harper, salary, June, 1914-------------------------- ------ 125.00
Laura Smith, stenographic services--------------------------- 75.00
Alex McDougall, postage ----------------------------------- 98.68
Ed Lomas, janitor services -------------------------------- 30.00
Max Schmidt, bookdealer -------------------------------- 241
H. & W. B. Drew Co., supplies--.-----------.. ------------- ..2.95
Dan Allen, freight and drayage--------------------- ----- 3.31
D. R. Cox Furniture Company. supplies..-----.. --------...-----.. 129.50
E. O. Painter Printing Co., printing-....----.----...------------ 2,247.75

Total ..--------.. -----------.........---------- -----..- $9.309-79

Appropriation for the year -- -----------------------$7.5oo.oo
Available from the preceding year ------ -------- ------ 2.418.47

$9.918-47
Total expenditures for the year ending June 30. 1914----------------- 9.309.79

Balance -------------- ------------------- ----$ 608.68



l 'LR Origlinal from
.. UNIVERSITY OF MICHIGAN


















STATISTICS ON

MINERAL INDUSTRIES OF FLORIDA

CALENDAR YEAR, 1914.


BY E. H. SELLARDS.

STATISTICS COLLECTED IN CO-OPERATION WITH THE UNITED STATES
GEOLOGICAL SURVEY.


CONTENTS.


PAGE
Clay and Clay Products ---------------------------------------- 14
Ball clay or plastic kaolin ---------------------------------------- 14
Brick and tile ---------------------------------------- 14
Clay tests for paving brick --------------------------------------- 15
Fuller's earth ---------------------------------------- 19
Lime ------------------------------------------ 20
Phosphate .----------------- --------------------------- --- 20
Sand and gravel --------------------------------------- 23
Sand-lime brick ---------------------------------------- 23
Water ------------------------------------------ ----- 24
Summary statement of mineral production in Florida during 1914--------- 24


Q ,0~vcj


Original from
UNIVERSITY OF MICHIGAN











STATISTICS ON MINERAL INDUSTRIES OF FLORIDA
FOR THE CALENDAR YEAR, 1914.

E. H. SELLARDS.




CLAY AND CLAY PRODUCTS.

BALL CLAY OR PLASTIC KAOLIN.

Two plants, The Edgar Plastic Kaolin Company and The Lake
County Clay Company, were engaged in mining ball clay in Florida
during 1914. In addition The Richmond China Clay Company had
a plant under construction with the expectation of operating during
1915. The value of the ball clay produced, although not separately
given, is included in the total mineral products of the State.

BRICK AND TILE.

The total number of common brick manufactured in Florida
during 1914 was 41,901,000, valued at $230,377. The quantity of
tile, hollow block brick and other clay products is not separately
given, but is included in making up the total mineral products of
the State.
The following firms in Florida have reported production of
brick or tile during 1914:

Barrineau Brothers, Quintette.
Campville Brick Company, Campville.
Clay County Steam Brick Company, Green Cove Springs.
Florida Brick Company, Brooksville.
Florida Industrial School for Boys, Marianna.
Gamble and Stockton Company, ro8 West Bay St., Jacksonville.
Hall and McCormac, Chipley.
Keystone Brick Company, Whitney.
McMillan Brick Company, Molino.
O. O. Mickler Brick Company, Callahan.
Ocklocknee Brick Company, Ocklocknee.
Platt Brothers, South Jacksonville.
Tallahassee Pressed Brick Company, Havana.
S L Origcinal from
.. : 14 UNIVERSITYOF MICHIGAN







ADMINISTRATIVE REPORT


REPORT ON CLAY TESTS FOR PAVING BRICK.*
As a country develops, the demand for information regarding
the clay products as well as the other natural resources, becomes the
more insistent. This is.particularly true in Florida where the exten-
sive use of brick for road paving has created a large demand for a
product that is not now being made in the State. At the present
time all the paving brick used in Florida is imported, and the ques-
tion is constantly being asked whether or not there exists in the
State a clay suitable for the manufacture of vitrified brick. A source
of domestic supply, if such can be found, will not only effect a sav-
ing in freight rates, but in addition will bring an important new in-
dustry into the State. In view of these facts the State Geological
Survey has undertaken to find, if possible, a clay in the State suit-
able for the manufacture of paving brick. Even should no paving
brick clay be found, the general information regarding clay deposits
of the State that will be obtained in. connection with these investiga-
tions will abundantly justify the undertaking."
In this work the State Survey has been particularly fortunate in
having secured during the past year the assistance of the United
States Bureau of Standards. This Federal Bureau maintains at
Pittsburgh, Pennsylvania, an excellently equipped clay testing lab-
oratory in which, through the generous co-operation of the Director
of the Bureau, the actual burning tests of the Florida clays have been
made. For this purpose twenty-five samples were collected by the
State Geological Survey and submitted to the Bureau during the
summer of 1914. Twenty-one counties in Florida are represented
in these tests. Each sample as shipped consisted of approximately
250 pounds of clay and was representative, as nearly as could be
judged, of the clay of the locality from which it was taken. The
burning tests have been made by experienced ceramists under favor-
able conditions and the results may be accepted with confidence.

PREPARATION OF SAMPLES.
After being received at the Pittsburgh laboratory the samples
were prepared by the ceramists who were making the tests as fol-
lows :
"Preparation of the Sample.-Each sample as received was
ground in a Stevenson pan and screened through a Io-mesh sieve.
.t*Fir" pkj---_ T7Y-ina Ffr--ltA
*First pqblishedapprs, tp t, A, IJIoRSITIY OF MICHIGAN
C MIR1 _Y F 1pCH IA,







16 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

A portion of the samples was tempered with water and wedged on
a marble slab until it acquired stiff mud consistency.
"Preparation of Test Pieces.-Twenty-four briquettes were
molded from each clay by pressing in the stiff mud condition on a
hand repress machine, the test pieces being'numbered consecutively
from I to 24. Test pieces Nos. I, 2, 3, and 4 from each batch were
weighed in the moist state and after drying, and the water of plas-
ticity calculated in terms of the dry weight of the clay. Linear
measurements were also made on test pieces Nos. I, 2, 3, and 4 and
the linear shrinkage in terms of the wet length of the briquettes de-
termined.
"Drying Treatment.-Each series of briquettes were allowed to
dry at room temperatures until they had acquired leather hard con-
sistency, the final drying being in an electrically heated drying oven
at 750 and 110o C.
"Burning.-The test pieces were burned in a down-draft test
kiln fired with natural gas. The duration of burning was about 36
hours, the kiln temperature being increased at the rate of 250 C.
per hour above 8500 C. The kiln temperatures were measured by
platinum-platinum rhodium thermocouples and recording millivolt
meters. Four burns were made on the 24 samples. The twenty-
four test pieces molded from each sample were arranged in the kiln
so that two could be drawn at regular temperature intervals. Thus
two briquettes from sample No. I were drawn at 8500 C., 9500 C.,
980 C., and so on to the final burning temperature. The briquettes
were dropped into hot sand as they were drawn from the kiln.
"Porosity Determinations.-The porosities of the briquettes
burned to the different temperatures were determined by the use of
W-D
the formula, -- x Ioo = 7% porosity. in which W = the weight
W-S
of the briquette saturated with water, D = the dry weight of the
briquette, and S the suspended weight of the briquette. Before
determining the wet weights the pieces were boiled two hours in
water in vacuo."
The examination of the clay samples thus prepared included the
determination of: The molding behavior; the water of plasticity in
percentage of dry weight: the drying behavior; the linear drying
shrinkage in terms of wet length; the linear burning shrinkage in
terms of dry lerrath _t, color after burning alrtfdthe percentage of
UNIVERSITYOF MICHIGAN







ADMINISTRATIVE REPORT


porosity at temperatures ranging from 850 to 1320 degrees C.
(15620 to 24080 F).
RESULTS.

Although, as will be seen in the report which follows, the tests
thus far made are negative, so far as paving brick are concerned, yet
the results obtained are such as to justify the continuation of the
investigation.
With regard to the tests as a whole it is of interest to find that
a fair number of the Florida clays of which samples were submitted
show satisfactory molding, drying and other working properties.
and may be used in making building brick, some being suitable also
for tile and face brick.
It is apparent that the progress of the investigation of Florida
clays would be much facilitated if the State Survey could have its
own testing plant. This applies not only to tests of clays for paving
brick but to the general study of clays for building and face brick
and tile, and of kaolins for pottery purposes. At present space in
which to install clay testing machinery is not available and the State
Survey can not make its own clay tests until adequate office and lab-
oratory space is provided. For the tests that are here reported the
Survey is indebted, as already stated, to the co-operation of the
United States Bureau of Standards.

REPORT ON SAMPLES.
The following report on individual samples will serve to illus-
trate the properties of the clays that have been tested. In reading
these returns it is well to remember that the tests were made pri-
marily to determine whether or not the clays would vitrify at tem-
peratures practicable in commercial kilns. It is doubtless true that
more favorable results may be obtained in many cases by the mixing
of various clays; this, however, remains to be tested.

Sample No. I, Jackson County. The clay works with some difficulty in the
stiff mud condition; water of plasticity in per cent of dry weight, 40.80%;
warped and cracked during the drying treatment; linear drying shrinkage in
terms of wet length, 9.95%; linear burning shrinkage in terms of dry length, at
850 degrees C., o.77% at ro0o C., 4.59%; at 1.130 C., 6.60%; at 1250 G., 7.55%;
color after burning, light red at lower temperature, changing to dark red at
higher; per cent porosity, at 850 degrees C.. 36.75%; at 950 C., 40.55%; at 980
C., 34.30%; at 1010 C., 30.30%; at o140 C., 24.20%; at 1070 C., 24.00%; at nxoo
C., 26.o1%; at 1130 C., 25.15%; at xx6o C., 23.65% ; at 1190 C., 23.60%; at 1220
C., 23.85% ; at 1250 C., 20.79%. A somewhat plastic and s fPltGkqf0 igh dry-
. : UNIVERSITY OF MICHIGAN







18 FLORIDA GEOLOGICAL SURVEY-SEVENTI ANNUAL REPORT.

ing and burning shrinkage. The clay retains a porous structure at 1250 degrees
C. (2282 degrees F.), and cannot be used in the manufacture of vitrified ware
burned in commercial kilns. The clay may be used in the manufacture of com-
mon and building brick.
Sample No. 2, Washington County. The clay possesses good-working plas-
ticity and molding behavior; water of plasticity, 36%; a few cracks developed
*by drying; linear drying shrinkage, 9.42%; linear burning shrinkage, at 850 de-
grees C., 0.55%; at 1oro C., 1.57%; at 1130 C., 7.75%; at 1250 C., 8.io%. A good
light buff color is developed by burning; per cent porosity, at 85o degrees C.,
36.80%; at 950 C., 35.30%; at 98o C., 34.75%; at 1olo C., 34.5o%; at ro40 C.,
30.75% ; at 1070 C., 25.70% ; at LIoo C., 22.45%; at 1130 C., 19.70%; at 11.6o C.,
17.95%; at 1190 C., 15.70%; at 1220 C., 14.60%; at 1250 C.. 12.55%. A buff
burning clay of good plasticity and a relatively high drying shrinkage. May be
used in the manufacture of buff colored face brick, although care must be ex-
ercised in drying. The clay must be burned above 1250 degrees C. in order to
attain low porosity.
Sample No. 3, Santa Rosa County. The clay has good working plasticity
and molding properties; water of plasticity, 28.90%; no drying difficulties; lin-
ear drying shrinkage, 6%; linear burning shrinkage, at 850 degrees C., 0.64% ;
at 1010 C., o.21%; at 1130 C., 1.44%; at 1250 C., 1.17% ; burns to salmon color,
changing to buff at higher temperature; per cent porosity, at 85o degrees C..
35.30%; at 95o C., 35.80%; at 980 C., 36.2o%; at to0o C., 34.86%; at 0o4o C.,
33.6o%; at o107 C., 32.15%; at 100o C., 31.10%; at 1130 C., 29.55%; at ii6o C.,
29.o5%; at 190o C., 28.80%; at 1220 C., 28.05%; at 1250 C., 27.30%. A clay pos-
sessing good working and drying qualities but which cannot be vitrified at the
burning temperatures of commercial kilns. Test pieces burned to 1250 degrees
C. are easily cut by a knife. This clay is of value only in the manufacture of
porous common building brick, etc.
Sample No. 4, Escambia County. Appears to have good working behavior
and plasticity; water of plasticity, 21.95%; drying behavior satisfactory; linear
drying shrinkage, 5.75%; linear burning shrinkage, at 850 degrees C., 1.28% ;
at Io0o C., o.o5%; at 1130 C., o.26%; at i25o C., 1.16%; color after burning, light
to dark red; per cent porosity, at 850 C., 28.65%; at 950 C., 29.30%; at 98o C..
28.2o%; at Io010 C., 27.9o%; at o4o0 C., 27.75%; at lo0o C., 25.85%; at Ioo C.,
26.95%; at 1130 C., 25.70%; at ii60 C., 27.95%; at 1190 C., 26.8o%: at r22o C..
19.90o%; at 1250 C., 20.2o%. A clay possessing good working and drying be-
havior, but one which retains a porous structure at temperatures as high as 1250
degrees C. The clay is suitable for common and face brick, etc., but not for
paving brick or other vitrified ware.
Sample No. 5, Walton County. Plasticity and working properties good;
water of plasticity, 28.30%; drying behavior satisfactory; linear drying shrink-
age, 6.75%; linear burning shrinkage, at 850 degrees C., o.34%; at ro0o C..
0.35%; at 113o C., 2.17%; at 12.50 C., 2.25%; color after burning, salmon to
light red; per cent porosity, at 850 degrees C., 33.6o%; at 950 C., 33.20% ; at 980
C.. 35.40%; at ioio C., 34.35%; at 1040 C., 32.80%; at xo70 C., 30.50%; at IToo
C., 29.85%; at 1130 C., 28.60%; at ii6o C., 27.55%; at x1go C., 27.80%; at 1220
C., 27.10% ; at 1250 C., 26.oo0. A red burning clay having good working and
drying behavior, but retaining a porous structure. Test pieces burned to 1250
SC. are easily scratched by a knife. This clay is suitable for the manufacture of
porous common and building brick. Not practical to vitrify in commercial kilns.
Sample No. r,.Duz'al Cqnty. Fairly plastic, ; j pgqo working qualities;
S : : UNIVERSITY OF MICHIGAN







ADMINISTRATIVE REPORT


water of plasticity, 27.4%; dries satisfactorily; linear drying shrinkage, 9.6%:
linear burning shrinkage, at 99o degrees C., o.o5%; at 1iIo C., 0.82%; at 1230
C., 2.34%; at 1320 C., 3.97%; red burning; per cent porosity, at 850 degrees C.,
28.1%; at 950 C., 26.8%; at 980 C., 25.7%; at oo10 C., 25.8%; at o040 C.,
24.8%; at 1070 C., 24.6%; at Ioo 'C., 22.5%; at 1130 C., 22.5%; at iI60 C.,
20.4%; at 1190 C., 16.6%; at 1220 C., II.5%; at 1250 C., 7.5%. A sandy surface
clay of fair working and drying behavior. A decrease in porosity is noted with
increase in temperature, although it is doubtful whether a vitrified product may
be manufactured from this material, owing to the relatively high temperatures
necessary.
Sample No. 12, Clay County. Very plastic and possesses fair working qual-
ities; water of plasticity, 34.4%; excessive drying shrinkage; linear drying
shrinkage, 12.22%; linear burning shrinkage, at 990 degrees C., 1.45%; at irIo
C., 3.48%; at 1230 C., 4.87%; red burning; per cent porosity, at 85o degrees C.,
24.4%; at 950 C., 22.7%; at 98o C., 19.6%; at Ioo1 C., 18.7%; 1040 C.,
18.7%; at 1070 C., 17.4%; at IIoo C., 17.3%; at 1130 C., 16.8%; at Ii6o C.,
16.9%; at 119o C., 16.o%; at 122o C., 14.4%; at 1250 C., 13.8%. A plastic red
burning clay having a high drying shrinkage. Care must be exercised in drying
heavy pieces. This clay has a relatively low porosity at commercial kiln tem-
peratures and attains a fairly dense structure.
Sample No. 21, Jefferson County. Medium plastic with fair working prop-
erties; water of plasticity, 32.6%; no drying difficulties; linear drying shrink-
age, 9.77%; linear burning shrinkage, at 990 degrees C., 0.22% ; at IIio C., r.o9% ;
at 1230 C., 0.55%; at 1320 C., 0.49%; buff burning; per cent porosity, at 990
degrees C., 35.6%; at 1o20 C., 34.0%; at 1050 C., 33.2%; at io8o C., 33.4%;
at IIIo C., 33.8%; at 1140 C., 33.6%; at 1170 C., 33.6%; at 12oo C., 33.7%;
at 123o C., 32.8%; at 12.60 C., 344%; at 1290 C., 33.7%; at 1320 C., 33.5%. A
sandy buff burning clay which retains an open porous structure at temperatures
up to r32o degrees C. (2408 degrees F.). May have some use in the manufacture
of soft porous common building brick.
Sample No. 22, Polk County. Medium plastic with fair working properties;
water of plasticity, 24.9%; no drying difficulties; linear drying shrinkage 6.28%;
linear burning shrinkage, at 950 degrees C., 0.37%; at Ioo C., 0.47%; at 1220
C.. 0.08%; at 1310 C., 0.24%; burs red; per cent porosity, at 950 degrees C.,
35.6%; at o010 C., 35.8%; at 1040 C., 35.6%; at 1070 C., 36.0%; at iwoo C.,
34.8%; at 1130 C., 33.8%; at II6o C., 33.8%; at 1190 C., 33.7%; at 1220 C.,
33.6%; at 1250 C., 33.7%; at 1280 C., 33.4%; at 1310 C., 33.6%. A sandy red
burning material which retains an open porous structure at temperatures up to
132o degrees C. May have some use in the manufacture of soft porous common
building brick.
FULLER'S EARTH.

The total production of fuller's earth in the United States dur-
ing 1914 was 40,981 short tons, an increase over the preceding year
of 2.387 tons. In addition to that produced, there was imported in-
to the United States during the year 22,302* short tons, a substan-
tial increase over the imports of the preceding year. Some fuller's

*From quarterly statement of imports, U. S. Department of Commerce.
Bureau of Foreign and Domestic Commerce. Original from
... K UNIVERSITY OF MICHIGAN






20 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

earth is exported from the United States, although the amount can
not be determined owing to the fact that this product is not listed
separately from other clays.
Florida is the chief producer of fuller's earth in the United
States, more than 75% of the total production during 1914 being
credited to that State. The other states which contributed to the
total output during 1914 were Arkansas, California, Colorado,
Georgia, Massachusetts, and Texas. The production in Florida,
although not separately listed, is included in making up the total
mineral production of the State. The fuller's earth of Florida is
used chiefly in clarifying mineral oils. although some is being pre-
pared also for vegetable oils.
The following companies are engaged in mining fuller's earth
in Florida: The Atlantic Refining Company, Ellenton; the Floridin
Company, Quincy, and Jamieson; the Florida Fuller's Earth Com-
pany, Ellenton; and the Fuller's Earth Company, Midway.

LIME.
The total' quantity of quick and hydrated lime made in Florida
during 1914 amounted to 12,376 tons. valued at $64,531. The com-
panies reporting production of lime in Florida during 1914 were as
follows:
Florida Lime Company, Ocala, Florida.
Live Oak Limestone Company, Live Oak, Florida.
Marion Lime Company, Ocala, Florida.
Standard Lime Company, Kendrick, Florida.

PRODUCTION OF PHOSPHATE ROCK IN FLORIDA
DURING 1914.*
Owing to the interruption of European shipment the produc-
tion of phosphate rock in Florida for the year 1914 shows a de-
crease over that of the preceding year. The output for 1913 was
2,584,794 long tons, while during 1914 the output, as reported
by the producers, was 2.097,864 long tons, a decrease of 486,930
tons. The decrease occurred in both the land pebble and the hard
rock districts; the percentage of decrease, however, is greater
for the hard rock phosphate deposits. That the reduced output
is due to the interruption of foreign shipment is shown by the
fact that while the export shows a marked decrease, the amount

*First published'as wdirlce statement, Aprilqjil trif roIm
*s UNIVERSITY OF MICHIGAN







ADMINISTRATIVE REPORT


of phosphate consigned for domestic shipments during 1914 is
greater than during 1913, by about 28,918 tons.
The total shipment of phosphate rock for 1914 as reported
by the producers was 2,138,891 long tons, of which 1,829.202 tons
were land pebble (including a small consignment of river pebble),
and 309,689 tons were hard rock phosphate. The river pebble
included in the shipments represents rock on hand from previous
years, as no river pebble is being produced at present. Of the
total shipments, 928,993 tons were consigned for export, while
1,209,898 tons were consigned for domestic use within the United
States. The export shipments were made up of land pebble
625,821 tons, hard rock 303,172 tons. The domestic shipments
consisted of land pebble 1,203,381 tons, hard rock 6.517 tons.
The production of land pebble phosphate was 1,787,597 tons as
against 2.107,256 tons during the preceding year, a reduction of
319,659 tons. The production of hard rock phosphate during 1914
was 31o,267 tons, as against 477,538 tons during the preceding
year, a reduction of 167.271.

SUMMARY OF PRODUCTION AND SHIPMENT OF PHOSPHATE IN FLORIDA
FOR THE YEAR 1914, BASED ON DATA SUPPLIED BY THE PRODUCERS.
Pebble Phosphate- Long Tons.
Production .------......-- ---........ -----------------..... 1,787,597
Consigned for export ------------------------------------ 625,821
Consigned for domestic shipment-------------o--------------- ,203,381
Total shipments ---------- --------------------------- ,829,202
Hard Rock Phosphate-
Production ---------------------------------- ---- 310,267
Consigned for export ------------------------------------ 303,172
Consigned for domestic shipment..------...----------.-- -- 6,517
Total shipments ------------------------------------- 309,689
Pebble and Hard Rock Phosphate Combined-
Production ----------------------------------------- 2,097,864
Consigned for export ------------------------------------ 928,993
Consigned for domestic shipment -....--....-------------------.. ,209,898
Total shipments ------ --------------- --------- 2,138,891
The value of the phosphate shipped from Florida during 1914
was as follows: Land pebble, including a limited amount of river
pebble, $5,442,547; hard rock. $r,912,I97. Total, $7,354,744.
The following is a list of the phosphate mining companies
of Florida. Of the companies on this list a few were idle in 1914;
most of these, however, carried rock in stock from which sales were
made, and wil, coiti eq pfrations when condkWff r e'Taavorable.
S4 .' UNIVERSITY OF MICHIGAN









22 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.


The number of companies that actually produced phosphate rock in

Florida during 1914 was twenty-five. Of these fourteen mined land

pebble phosphate and eleven mined hard rock phosphate.


LIST OF THE PHOSPHATE MINING COMPANIES OF FLORIDA.

Acme Phosphate Co. ......................Morriston. Fla.
Amalgamated phosphate Co. ..............25 S. Calvert St., Baltimore, Md., and Chi-
cora, Fla.
Armour Fertilizer Works ..................Bartow, Fla.. and Union Stock Yards, Chi-
cago, Ill.
P. Bassett (Successor to Central Phosphate
Co.) ...................................... Newberry, Fla.
Peter B. and Robert S. Bradley ..........92 State St., Boston, Mass., and Floral City,
Fla.
J. Buttgenbach & Co. ................... Holder. Fla.
C. & J. Camp .............................Ocala. Fla.
Charleston, S. C., Mining and Manufactur-
ing Co. ................................. Richmond, Va., and Ft. Meade. Fla.
Compagnie Generale des Phosphates de la
Floride ................................ Paris. France, and Pembroke, Fla.
Coronet Phosphate Co. ....................Lakeland, Fla., and 99 John St.. New York.
Cummer Lumber Co ..................... Jacksonville and Newberry, Fla.
Dominion Phosphate Co. .................. Bartow, Fla.
Dunnellon Phosphate Co. .................. Rockwell, Fla.
Dutton Phosphate Co. .....................Gainesville, Fla.
Export Phosphate Co. ....................Mulberry. Fla., and 53 State St., Boston,
Mass.
Florida Mining Co. ........................165 Broadway. New York, and Mulberry,
Fla.
Florida Phosphate Mining Corporation ....Norfolk, Va., and Bartow. Fla.
Franklin Phosphate Co. .................. Newberry, Fla.
Holder Phosphate Co. .................... Ocala and Inverness. Fla.
International Phosphate Co. ...............27 State St., Boston, Mass.,'and Ft. Meade.
Fla.
Interstate Chemical Corporation ...........Charleston, S. C., and Bowling Green, Fla.
Istachatta Phosphate Co. ................. Istachatta, Fla.
Lakeland Phosphate Co. ..................Lakeland, Fla.
Mutual Mining Co. ........................Savannah. Ga., and Floral City, Fla.
Meredith-Noble Phosphate Co. ............Romeo, Fla.
Palmetto Phosphate Co. .................. Baltimore. Md., and Tiger Bay. Fla.
Peace River Phosphate Co. ................ Arcadia, Fla.
Pebbledale Phosphate Co. .................Mulberry. Fla.
Phosphate Mining' Co. ...................55 John St.. New York, and Nichols. Fla.
Pierce Phosphate Co. ...................... 2 Rector St.. New York, and pierce. Fla.
Prairie Pebble Phosphate Co. ............ 16 Broadway. New York, and Mulberry.
Fla.
Schllmann & Bene ........................Ocala. Fla.
Societe Franco-Americalne des Phosphates
de Medulla (Successor to Standard Phos-
phate Co.) .............................. Christina, Fla.
Southern Phosphate Development Co. ....... ala and Inverness. Fla.
T. A. Thompson ........................... Ft. W white. Fla.
Swift & Co. ................................ Bartow. Fla.

SUMMARY OF PRODUCTION AND SHIPMENT OF FLORIDA PHOSPHATE

FOR THE YEARS 1908, 1909. 1910. 1911. 1912, 1913

AND 1914 (LONG TONS).

Pebble Rock- 19V9. 1910. 1911. 1912. 1913. 1914.
Production .......... 1..334,569 1.637,709 2,020.478 2,043.486 2,107.256 1.7.7,597
Exported .............509,341 606.110 703,589 732,651 887,398 625.821
Domestic ............ S19.701 995.728 1,274,056 1,204,502 1.168,084 1,203,381
Total shipments .... 1,329,042 1,601,838 1,977.645 1,937,153 2,055,482 1,829,202
Hard Rock-
Production .......... 527.582 392,088 474,094 536.379 477,538 310,267
Exported ............ 496,645 461,353 462.072 470.354 476,898 303.172
Domestic ............ 17,456 18,745 16.723 15,425 12.896 6.517
Total shipments ..... 514.101 480,098 478,795 485,779 489,794 309,689
Pebble and Hard Rock Combined-
Production ......... 1,862,151 2,029,797 2,494,572 2,579.865 2,584.794 2,097,864
Exported ............ 1,005,986 1,067.463 1.165,661 1,203,005 1,364,296 928,993
Domestic .......... 837,157 1,014,473 1,290,779 1,219.927 1.180,980 1,209,898
Total shipments ..... 1.843,143 2,081.936 2,456,440 2,422.932 2,545,276 2,188,891
Total phosphate produced in Florida 1908 to 1914 inclusive ................ 15.567.054
Total phosphate exported 1908 to 1914 inclusive. .......................... 7,836.675
Total domestic shipments 1908 to 1914 Inclusive ....................... 7,184,895
Total recorded shi nen ts 19 8 t 1.914 Inclusive ....... .. lC iaf .lOc l.l .... 15,021.870
Total driiobnt: of, iofht' ced In FloriJ9p-I A 27,962,78f
mining in 1888 to 1914(1.lcluslve. ....... JLJ t. U 27,962,785







ADMINISTRATIVE REPORT


SAND AND GRAVEL.
The sand produced in Florida is used chiefly for building pur-
poses, although a limited amount is used as moulding sand. The
gravel produced finds its chief use for road-making and road ballast.
The total production of sand and gravel for 1914 was 177,241 tons,
valued at $54,12o.oo. Of this amount 98,435 short tons, valued at
$1o,637.00, was gravel, the balance being sand of the grades men-
tioned.
The companies reporting the production of sand and gravel in
Florida during 1914 are the following:
Atlantic Coast Line Railroad Company.
Florida Sand and Shell Company, Tampa, Fla.
Interlachen Gravel Company, Interlachen, Fla.
Logan Coal and Supply Company, Jacksonville, Fla.
W. E. Long, Orlando, Fla.
R. L. Martin, Ocala, Fla.
Walter L. Wescott, Orlando, Fla.
Woodmar and Company, Ocala, Fla.
SAND-LIME BRICK.
The materials used in the manufacture of sand-lime brick are
sand and lime. The bonding power of the brick is due to the chem-
ical reaction between these ingredients. The chemical changes oc-
cur in presence of heat, pressure and moisture and result in the
formation of hydro-silicates of calcium and magnesium.
The sand used in the manufacture of sand-lime brick should be
comparatively pure and preferably with some variation in the size
of the grains. The mixture of lime, sand and water, is cut in the
form of bricks and conveyed to a hardening cylinder. Necessary
heat and pressure are obtained in the hardening cylinder adapted
for the purpose. The sand-lime bricks are placed in this cylinder
and subjected to a pressure and temperature which vary according
to the method of treatment.
Four companies were actively engaged in the manufacture of
sand-lime brick in Florida during 1914 as follows: The Bond Sand-
stone Brick Company, Lake Helen, Fla.; The Composite Brick
Company, 425 St. James Bldg., Jacksonville, Fla.; Plant City Com-
posite Brick Company, Plant City, Fla.. and the Valrico Sandstone
Company, Valrico, Fla.
The total production of sand-lime brick in Florida during 1914
was valued at $,(5,43-M.(M h( sis an increas&b'i$ ~'.oo in
value over that of 1913 UNIVERSIT-OFMrHIGA







24 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

WATER.

The springs of Florida are famous for their large volume of
flow as well as for the clearness and beauty of their waters. Many
of these springs are used as health resorts, while from others the
water is sold for medicinal or table use. The total sales of mineral
and spring water in Florida during 1914, as shown by the returns
from the owners of springs and wells, amount to 231,I60 gallons,
valued at $24,738. The average price thus approximates ten cents
per gallon. The total sales are divided as follows: Medicinal wa-
ters, $3.315; table waters, $21,423.
The following is a list of those who report having sold spring or
well water during 1914, together with the name of the spring or well
from which taken:
Chumuckla Mineral Springs and Hotel Company, Chumuckla Mineral Springs,
Chumuckla, Florida.
Espiritu Santo Springs Company, Espiritu Santo Springs, Safety Harbor, Florida.
Lackawanna Water and Ginger Ale Company, Lackawanna Springs, Jackson-
ville, Florida.
L. H. McKee, Quisisana Spring, Green Cove Springs, Florida.
Magnesia Spring Water Company, Magnesia Spring, Grove Park, Florida.
Magnolia Springs Hotel Company, Magnolia Spring, Magnolia Springs, Florida.
Nathaniel Brewer, Jr., Newport Springs, Newport, Florida.
Orange City Mineral Springs Company, Orange City Mineral Springs, Orange
City, Florida.
Panacea Springs Company, Panacea Springs, Panacea, Florida.
Ponce de Leon Springs.Corp., DeLeon Springs, DeLeon Springs, Florida.
Purity Springs Water Company, Purity Spring, Tampa, Florida.
Tampa Kissengen Wells Company, Stomawa Mineral Well, Tampa, Florida.
Vincent Bros., Wekiva Springs, Apopka, Florida.

SUMMARY STATEMENT OF MINERAL PRODUCTION
IN FLORIDA DURING 1914.
Common or building brick. 41,901 MI., valued at--------------$ 230.377.00
Lime, including quick and hydrated lime. 12,376 tons, valued at----.... 64,531.00
Limestone, including ground limestone for agricultural use and
crushed rock for railroad ballast, concrete apd road material---- 343.779.00
Mineral waters. 231.160 gallons. valued at--------------------- 24,738.00
Phosphate rock, 2,097.864 long tons, valued at ----------------- 7,354744.00oo
Sand and gravel, including building and moulding sand and gravel,
177,241 short tons, valued at ----------------------------- 54.12o.00
Sand-lime brick, including common and front brick, 18476 thousand,
valued at ---------------------------------- -----o105.435.00
Mineral products not separately listed, including ball clay, drain tile,
vitrified block, diatomaceous earth, fuller's earth-----..------ 443,964.00

Total mineral production valued at------------1~4i.m-f-f_- t-----$8,621,688.00
- UNIVERSITY OF MICHIGAN































THE PEBBLE PHOSPHATES OF FLORIDA.


BY E. H. SELLARDS.


OriQinal from
UNIVERSITY OF MICHIGAN


~1 Ti-













CONTENTS.
PAGE
Introduction --------------- ----------------------------- --- 29
Location of Deposits ---------------------------------------- 29
Problems to be Accounted For ------------------ --------------- 31
Summary of Explanation Offered ------------------------------ 31
Geology of Southern Florida -------------------------------------- 32
Stratigraphic Succession -------------------------------------- 33
Eocene -------------------------------------------- 33
Ocala Formation ---------------------------------------- 33
Oligocene ---------------------------------------- 33
Tampa Formation ---------------------------------------- 33
Alum Bluff Formation ---------------- -------------------- 34
Pliocene ---------------------------------------- 41
Bone Valley Formation ----------------- ------------------- 41
Pleistocene ---------------------------------------- 44
Geological Structure ---------------------------------------- 45
Succession and Thickness of Formations as shown by Well Records 45
Geologic History ---------------------------------------- 54
Period of Deposition of Eocene Sediments ---------------------- 54
Post-Eocene Period of Emergence and Erosion ----------------- 54
Period of Deposition of Upper Oligocene Sediments -------------- 54
Post-Oligocene Period of Emergence and Erosion ---------------- 55
Period of Deposition of Pliocene Sediments ---------------------- 55
Changes in Level during Pleistocene Time ----------------------- 55
Summary of the Geologic History ----------------------------- 56
The Land Pebble Phosphate Deposits ----------------- -------------- 57
The Phosphate Bed a Pebble Conglomerate Accumulated under Marine
or Estuarine Conditions ------------------------------------- 58
Structural Features and Local Details in the Phosphate Bed, the Over-
burden, and the Bed Rock ----------------------------------- 61
Unconformity within the Phosphate Bed ------------------------ 6r
Irregularities in the Top Surface of the Bed Rock ---------------- 63
Absence of Formations of the Miocene Period ------------------- 63
Lack of Continuity of the Phosphate Bed ----------------------- 64
Variations in the Vertical Section ---------------------------- 64
Variations in the Phosphate Bed when Traced Laterally ---------- 64
Variation in Percentage of Phosphate Pebble to Matrix ------------ 64
Variation and Thickness of the Pebble Conglomerate ------------- 65
Color of the Rock -------------------------------------- 65
Variation in the Grade --------------------------------------- 65
Sink Holes --------------------------------------- --- 66
Stream Beds ----------------------------------------- 66
Clay Beds Beneath the Pebble Phosphate Conglomerate ------------ 66
Sand and Fine Pebble Beneath the Pebble Phosphate Conglomerate-- 67
Iron Rock in the Overburden -------------------------------- 67
Incoherent Surface Sand and Soil ---------------------------- 68
Hardpan i the Sub-Soil --------------.a.rr n'---------- 68
-" 2(6 UNIVERSITY OF MICHIGAN








CONTENTS AND ILLUSTRATIONS 27
PAGE
Vesicular and Calcareous Sand Rock in the Overburden ------------ 68
Overburden Absent or Reduced in Thickness -------------------- 68
Bog Iron Ore in the Overburden ----------------------------- 68
Secondary Enrichment in the Phosphate Bed ---------------------- 69
Fossils of the Land Pebble Phosphate Deposits -------------------- 71
Derived from the Bed Rock ------------------------------------ 71
Derived from Miocene Stream and River Deposits -------------- 71
Contemporaneous with the Phosphate Deposits------------------ 72
Land Dwelling Animals----------------------------- 72
Marine Animals ---------------------------------------- 73
The River Pebble Phosphate Deposits ----------------- ------------- 76
Fossils from the River Pebble Phosphate Deposits ------------------ 76
Local Deposits of River Pebble Phosphates ----------------------- 78
Peace Creek ---------------------------------------- 78
Alafia River ------------------------------------------ 81
Manatee River ---------------------------------------- 82
North Creek -------- ------------------------------- 82
Caloosahatchee River --------------------------------------- 82
Black Creek --------------------------------------- 83
Olustee Creek ---------------------------------------- 83
Allapaha River ---------------------------------------- 83
Sopchoppy River --------------------------------------- 83
Relation Between the Hard Rock and the Pebble Phosphates of Florida--- 84



ILLUSTRATIONS.
PAGE
Fig. i. Map to show the location of phosphate deposits in Florida ------ 30
Fig. 2. View to show overburden of the land pebble phosphate ---------- 42
Fig. 3. Mining River pebble phosphate ----------------------------- 44
Fig. 4. Diagrammatic sketch to show the structure of Florida ---------- 53
Fig. 5. Diagrammatic sketch to show conditions under which the land peb-
ble phosphates were accumulated ------------------------- 59
Fig. 6. Unconformity in the phosphate bed ------------------------- 62
Fig. 7. Top view of land tortoise ----------------------------------- 70
Fig. 8. Part of lower jaw of a gavial---------------------.------- 74
Fig. 9. Side view of land tortoise--------------------------- ---- 75
Fig. xo. Jaw and teeth of Chlamytherium-------------------------- 8o
Fig. ir. Ostrea from the Bone Valley formation ------------------- 83
Fig. 12. Tooth of the elephant -------------------- --------------- 85
Fig. 13. Alum Bluff on the Apalachicola River ----------------------- 87
Fig. 14. View in Pit of Pembroke Mine ----------------------------- 89
Fig. I5. Mining phosphate rock by hydraulic method ------------------- 89
Fig. 16. Phosphate washer -------------------------------------- 89
Fig. 17. Pit of Palmetto Phosphate Company ------------------------ 91
Fig. 18. Pit of Pierce Phosphate Company --------------------------- 91
Fig. 19. Plant of the Pierce Phosphate Company --------------------- 91
Fig. 20. Sample of Phosphatic Marl from Black Creek ---------------- 93
Fig. 21. Sample from Phosphate Bed ----------------------------- 93
Fig. 22. Phosphate PebblQs wasw e om the Bed Rock Clural ui-fci. 95
; UNIVERSITY OF MICHIGAN








28 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

PAGE
Fig. 23. Phosphate Pebbles from the Phosphate Beds ------------------ 95
Fig. 24. Phosphate Pebbles from the Bed Rock ---------------------- 97
Fig. 25. Phosphate Pebbles from the Phosphate Bed -------------------- 97
Fig. 26. Sharks' Teeth -------------------------------------- -- 99
Fig. 27. Phosphate Pebble -------------------------------------- 99
Fig. 28. Sharks' Teeth ------------------------------------ --- 99
Fig. 29. Skull of Gavial, top side ------------------------------------ lot
Fig. 30. Skull of Gavial, lower side ------------------------------ 1o
Fig. 31. Snout of the Cetacean ------------------------------------- o3
Fig. 32. Part of the Skull of a Cetacean --------------------------- 10o3
Fig. 33. Vertebrae of a Cetacean ----------------------------------- 05
Fig. 34. Tooth of a Mastodon ------------------------------------- o5
Fig. 35. Tooth of a Mastodon ----------------- ------------------- 107
Fig. 36. Tusk of Mastodon ---------------------------------------- 07
Fig. 37. Lower Jaw of Rhinoceros ---------------------------------- 107
Fig. 38. Tip of Jaw of Rhinoceros ----------------------------------- og
Fig. 39. Base of Lower Jaw of Rhinoceros ------------------------ og
Fig. 40. Equus, First or Second right upper Molar -------------------- I
Fig. 41. Equus, Second left lower Premolar ------------------------ 11
Fig. 42. "Equus, First left upper Molar ------------------------------ IIt
Fig. 43. Equus, Left lower Molar or Premolar ---------------------- rI
Fig. 44. Hipparion --------------------------------------- ----
Fig. 45. Mammut americanum ------------------- ---------------- 113
Fig. 46. Elephas columbi var. ----------------------------------.--- 113
Fig. 47. Equus, lower tooth ------------------------------------- 1 13
Fig. 48. Chlamytherium septentrionalis, plates and tooth ---------------- 115
Fig. 49. Chlamytherium septentrionalis, lower jaw from above ---------- 115
Fig. 50. Capybara-like rodent, teeth ------------------------------------ 115
Fig. 51. Chlamytherium septentrionalis, right lower jaw, exterior view--- II6
Fig. 52. Chlamytherium septentrionalis, right lower jaw, interior view---- I16






















S I Original from
UNIVERSITY OF MICHIGAN










THE PEBBLE PHOSPHATES OF FLORIDA.
E. H. SELLARDS.

The phosphates of Florida are known commercially as hard rock,
land pebble, and river pebble. An explanation of the origin of the
hard rock phosphate was suggested by the writer in a paper published
in 1913*. The present paper relates to the origin, location and con-
ditions of deposition of the land and the river pebble deposits of the
State.
LOCATION OF DEPOSITS.
The land pebble phosphate deposits of Florida known to be
workable are found in southern Florida, in Hillsboro, Polk and De-
Soto counties. The belt of country in which mines are now operat-
ing extends from near Plant City on the north to near Bowling
Green on the south, a distance in a north-west to south-east direction
of approximately thirty miles. The width of the productive belt
probably nowhere exceeds ten or fifteen miles. The formation, of
which these workable beds are a part, has, however, as will be
shown, a much greater extent.
The term river pebble is applied to phosphates that have accumu-
lated along streams. The best known of the river pebble deposits
and the only ones that have been worked commercially are those
found in the valley of the Peace River in DeSoto County and in
the valley of the Alafia River in Hillsboro County, although smaller
deposits are known at many other localities in the State.
The hard rock phosphate deposits are found in north central
Florida forming a belt paralleling the Gulf Coast for a distance of
about Ioo miles. The approximate location of the different types
of phosphate in Florida is shown on the accompanying outline map.
Phosphate mining in Florida was begun on Peace River in 1888,
the first rock produced being river pebble; in that year, also, the
hard rock phosphates were discovered and were rapidly developed.
Production of land pebble phosphate in Florida was begun probably
in 189o, the first shipment having been made in 1891. No river
pebble is now being mined in Florida; of the hard rock phosphate the
output for some years past has approximated one-half million tons
per annum, while of land pebble, the production at the present time
under normal conditions is in excess of two million tons per annum.
*Fla. State. Gkv. r .j 6tWpi Rept., pp. E1T il trOMCIGAN
VE29 OF MICHIGAN







30 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.


MAP 01F L

PLOR IDA


Showing the location
of the phosphate
aeposits.

*B Hard Rook
Phosphate

WLand Pebble
H hosphate

*0 River Pebble
bhodphate


Highlands
of Florida


Fig. I.-Sketch map of Florida showing the location of phosphate deposits.


OrigJinal from
UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


PROBLEMS TO BE ACCOUNTED FOR.
Among the problems to be accounted for in connection with
the origin of the pebble phosphate deposits are the following: (I).
The source of the phosphate pebble found in the land and river
phosphate deposits. (2). The source of the materials of the
matrix, including sand, clay, vertebrate, invertebrate and plant fos-
sils. (3) The conditions under which the formation accumulated.
(4). The minor problems of the formation, such as variation in
grade of rock, irregularities in the beds, lack of continuity of the de-
posits, variation in the thickness of the phosphate stratum and in the
richness of the matrix. While all of the many perplexities met
with in mining may not be explained in this report, it is believed that
there is presented here a rational basis from which the causes of
many of the seemingly erratic variations in the phosphate beds may
be understood.
SUMMARY OF THE EXPLANATION OFFERED.
The explanation offered, briefly summarized, is as follows: The
land pebble phosphate bed is a conglomerate of pebble, sand and clay
formed by the sea advancing probably with minor oscillations in
level across the exposed surface of the great phosphatic marl known
to the miners as the "bed rock." The immediate source of the phos-
phate rock as well as the other materials of the matrix is therefore
from the "bed rock" marl. The sands of the overburden represent
the part of the formation that was deposited following the accumula-
tion of the pebble conglomerate. Within the phosphate bed the grade
of rock is enhanced through secondary enrichment brought about by
the agency of surface waters moving downward and laterally
through the formation. The minor variations in structure in the
beds find their explanation in the varying conditions that prevail in
shallow water deposits. The fossils in the phosphate deposits are
derived in part from the earlier formations, and in part represent
animals that were living at the time the deposits accumulated. The
original source of the phosphorus is the primitive rocks of the earth's
crust through which it is widely disseminated and from which it
finds its way into sedimentary rocks by diverse processes, some of
which have been enumerated by the writer in an earlier paper of this
series.* The river pebble deposits were accumulated in the beds of
streams during either Pleistocene or recent time, the pebble having
been washed out of the older formations.
tae"e. SixthAi RptiOr iginal f romi
*Fla. State Geol. Suv.,Sixth A. Rept.. pp. 71iWV;TY OF MICHIGAN







32 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

GEOLOGY OF SOUTHERN FLORIDA.
If the origin of the phosphate deposits is to be understood it
becomes necessary first of all to obtain a clear conception of the
geology of the country in which they are found. The areal and
structural geology of southern Florida is now known with a reason-
able degree of completeness and from this may be deduced the geo-
logical history. The formations exposed at the surface in this part
of the State include the following: The Tampa and Alum Bluff
formations which are of Oligocene age; the Bone Valley formation,
which contains the land pebble phosphates and is of Pliocene, or pos-
sibly late Miocene age; and the Peace Creek beds which contain
the river pebble phosphates, and are of Pleistocene age. The Ocala
limestone although not seen at the surface in southern Florida, as
it lies buried to a considerable depth by these later formations, has
nevertheless an important relation to the phosphate industry since
it is reached by all the deep wells of the region, and from it chiefly
is obtained the water supply for hydraulic mining.
It is a pleasure to acknowledge in this connection the credit that
is due those whose investigations have contributed to a knowledge
of the geology of southern Florida. Among these should be men-
tioned in particular Allen (1846), Conrad (1846), Tuomey (1850),
Smith (1881), Heilprin (1887), Dall (1890-1903, 1915), Eldridge
(1893), Shaler (1893), Matson and Clapp (1909) and Vaughan
(1910). Without the knowledge of the general geology of Florida,
to which these writers have contributed, an explanation of the origin
of the pebble phosphate deposits could not be given at this time.
A bibliography of the geology of Florida may be found in the
First Annual Report of the State Survey pp. 54-o08. In addition
the papers relating specially to the phosphates of Florida are listed
and reviewed in the Fifth Annual Report of the State Survey, pp.
67-o8, 1913.









S .O. ) ricginal from
: -UNIVERSITYOF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


STRATIGRAPHIC SUCCESSION.
EOCENE.
OCALA FORMATION.

Of the formations mentioned the Ocala is the earliest or oldest,
being probably of Eocene age.* This formation consists largely of
very pure and for the most part light colored limestones which have
been fully described in the earlier reports of the State Survey.
These limestones lie at or near the surface over a large area in west
central Florida, the hard rock phosphate resting upon them, as ex-
plained in the writer's paper relating to those deposits. To the
south, north and east of the hard rock phosphate area and probably
to the west als6 the Ocala passes beneath the surface. In Sumter
County limestones' of the Ocala formation are seen as far south as
Panasoffkee and as far east as Wildwood. In Hernando County
these limestones are seen somewhat south of Croom. The south-
ward dip of the formation is further indicated by the fact that at
Tiger Bay in Polk County the Ocala is first encountered at a depth
of at least 360 feet. That the formation dips to the east has been
shown by numerous well records.

OLIGOCENE.
THE TAMPA FORMATION.
The Tampa formation which consists chiefly of impure clayey
limestones together with notable flint beds, is well exposed along
the Hillsboro River at and above Tampa and on Hillsboro Bay.
The silicified beds of this formation exposed at Ballast Point and
elsewhere on Tampa Bay have received the name of the Tampa
Silex beds, while the limestone and marls of the formation in the
vicinity of Tampa are known as the Tampa limestone. In general
the Tampa limestone may be expected to dip in passing to the south
and east. This is doubtless true although the formation is with dif-

*Unpublished manuscript of C. W. Cooke and R. S. Bassler. As early as
1888 Mr. Joseph Willcox obtained Zeuglodont remains from the Ocala limestone
at Ocala. A second specimen of a Zeuglodont was obtained at Ocala in 1913
by C. W. Cooke of the U. S. Geological Survey and Herman Gunter of the
Florida Geological Survey. In 1914 the writer obtained through Mr. Franz
Weston from pit No. 12 of the Cummer Lumber Company near Newberry some
whale vertebrae which have been determined by J. W. Gidley as Basilosaurus
brachyspondylus. Mr. Gidley adds that the specimen should be of Eocene age
(Letter of ov. T. OriginalI fro m
-_ A UNIVERSITY OF MICHIGAN







34 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

ficulty recognized from well samples. The term Tampa formation
is here used as defined in the Second Annual Report of this Survey.
1909.
With regard to the exact equivalence in the Oligocene series, of
the Tampa Silex beds and the Tampa limestone, there may be as yet
some doubt. In their study of the geology and stratigraphy of Flor-
ida published in the Second Annual Report of the State Survey.
1909, Messrs. Matson and Clapp expressed the view that the
Tampa formation of southern Florida is contemporaneous with the
Chattahoochee formation of the Apalachicola River section. This
view is supported also by Vaughan*. Dr. W. H. Dall, however, is
of the opinion that the Tampa limestone is of later age than the
Chattahoochee limestone.t While the determination of the relation
of these beds is of importance in the study of the stratigraphy of
Florida, the problem does not enter essentially into the study of the
phosphate deposits. For this reason the correlation of these forma-
tions will not be further discussed at this time, since for the present
it is sufficient to recognize that the Tampa formation, as the term is
here used, represents the earliest upper Oligocene deposits of south-
ern Florida.
THE ALUM BLUFF FORMATION.
The Alum Bluff formation in Florida represents the uppermost
or latest of the Oligocene series. As now understood the formation
is a very extensive one reaching from the Apalachicola River in
west Florida, east and south through the peninsula to the Gulf.
forming a broad belt lying north and east of the older formations
previously described.
The relation of the Alum Bluff formation to the Chattahoochee
limestone of northern Florida as well as to the Tampa limestone of
southern Florida is probably throughout that of conformity, the
change from the one formation to the other being gradual. The
Alum Bluff, however, contains a larger amount of sand and clay
than do the other formations, thus indicating a marked change in
the conditions of deposition. Another notable feature of the Alum
Bluff formation to which reference will be made later, is the fact

*Vaughan, T. W., a contribution to the Geologic History of the Floridian
Plateau. Carnegie Institution of Washington, Publication No. 133, pp. 99-185,
1910.
tDall. W. H., U. S. Geol. Surv. Bull. 84, IP92; Wag. Free Inst. Sci., Vol. 3,
Pt. 6, 1903; U.. &National luseum Bull. 90. I qgginal from
l ( :" 4 UNIVERSITY OF MICHIGAN








PEBBLE PHOSPHATE DEPOSITS.


that it contains throughout more or less phosphatic material. The
formation is of special interest in connection with the pebble phos-
phate from the fact that it forms the bed rock of the phosphate
mines and, as will be subsequently shown, is the parent formation
from which the pebble phosphate deposits were derived.
The type locality of the Alum Bluff formation is at Alum Bluff
on the Apalachicola River. At this place the Alum Bluff consists
chiefly of gray phosphatic and calcareous sands. Among the de-
tailed sections on the Apalachicola River described by the writer and
Herman Gunter in the Second Annual Report of this Survey were
the following:
Section at Rock Bluff.
Rock Bluff lies five and one-half miles in a direct line south of southwest
of Aspalaga Bluff, or twelve and one-half miles from the State line. It is the
second point at which the river in Florida strikes the east border of the river
valley. That part of Rock Bluff which faces the river lies near the southwest
corner of Section 17, R. 7 west, T. 2 north. The basal part of the following
section is made near the north end where the river channel first strikes the bluff.
From this point the level was transferred north across a small stream to that
part of the bluff which does not now directly face the river.


Thickness Height above river
of stratum. (stage of Mar. 5. 5909).


1i. Covered in the line of the section to the
top of the bluff from the river, about
% mile ----------------------- oo
Io. Fuller's earth (exposed) -------------- 3
9. Ledge with shells -------------------- I
8. Gray sand ---------------------- 5
7. Ledge with shells -------------------- 2
.6. Gray sand with lime inclusions ------- 5
5. Covered --------------------------- 2
4. Light gray calcareous sand containing
a trace of phosphate (by transfer-
ring the level across a small branch
to the north the section is continued) 30
3. Bluish green to gray sands, variable in
character. Lime inclusions begin to
appear in these sands at 20 feet from
the base. These become more num-
erous until the material passes
gradually into the sandy-marl above- 34
2. Compact sandy marl with concretions
near the base and with an ostrea
layer 6 feet above the base ------ 8
I. Chattahoochee limestone above water
level ------------------------- o
Q 0 )cb


feet
feet
foot
feet
feet
feet
feet



feet


feet


feet


feet.
feet.
feet.
feet.
feet.
feet
feet


52 to 82 feet.





18 to 52 feet.


o1 to 18


feet.


feet o tri r IO feet.
On cRinal rom I
UNIVERSITY OF MICHIGAN








36 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

While the dividing line between the Chattahoochee limestone and
the Alum Bluff formation is not well marked, it is probable that
in this section about 90 feet of the Alum Bluff formation is exposed
including Nos. 2 to Io of the section.

Section at Alum Bluff, Liberty County.
The following section was made at Alum Bluff a short distance north of the
middle of the bluff at a point where a recent landslide (reported to have oc-
curred in 1905 or 1906) has left the bluff bare of vegetation. The measurements


of this section were made by hand level.
Thic
of stral
8. Pale yellow incoherent sand ---------- 30
7. Reddish and purple sands and sandy
clays partly covered toward the base 70
6. Covered --------------------------- 6
5. Dark colored sandy non-fossiliferous
clays, in places tasting of alum ----- 17
4. Dark or gray marls, highly fossiliferous 14
Unconformity.
3. Laminated and cross bedded sands and
clays, and blue sands; in places
absent ------------------------- 3
Apparent unconformity.
2. Light gray calcareous sands or sand-
stone -------------------------- 16
I. Sands, slightly indurated and weathering
yellow upon exposure -------------- o


kness Height above river
turn. (stage of Mar. 5, 1909).


feet

feet
feet

feet
feet



feet


feet


feet


r36 to 166 feet.


to 136 feet.
to 66 feet.


to 60
to 43


feet.
feet.


26 to 29 feet.


10 to 26 feet.

o to io feet.


The light gray sandstone (No. 2) of this section is apparently the same as
No. 4 of the Rock Bluff section, the stratum having been recognized at several
intermediate localities along the river bluff between the two localities and on
tributaries entering the river. Samples from this stratum gave the following
analyses. No. I is from Rock Bluff (No. 4 of the section). No. 2 is from Alum
Bluff (No. 2 of the section). No. 3 from an exposure on a tributary to Sweet
Water Creek Sec. 5, T. I N., R. 7 W. All samples were collected by the writer.
Analyses made for the State Survey in the office of the State Chemist, B. H.
Bridges, Analyst.
No. i. No. 2. No. 3.


Silica (SiO,)---------------- ----------------
Calcium carbonate (CaCO)1 -------------------
Magnesium carbonate (MgCO3) ----------------
Iron and Alumina (FeOs and AO) ----------------
Phosphoric acid (PO) -----------------------
Sulphate (SO) ---------------------------------
Moisture (Too degrees F.) -------------------------


48.44
38.57
1.68
2.88
Trace
Trace
1.37


53.02
38.57
1.84
3.96
0.22
Trace
1.60


34.03
35-35
26.00
3.20
Trace
Trace
1.32


'Calculated from the oxides. No. I, Calcium oxide, 21.60; magnesium oxide,
0.80. No. 2, Calcium oxide, 21.60; magnesium oxide, 0.88. No. 3, Calcium oxide,
r80; magnesim o I39. Oriinal from
UNIVERSITY OF MICHIGAN








PEBBLE PHOSPHATE DEPOSITS.


Above this stratum at Rock Bluff is found gray and blue sands leading up
to the workable fuller's earth stratum. At Alum Bluff the fuller's earth fails to
appear, and the top surface of the calcareous sand stratum is irregular as if by
erosion. In some parts of the bluff fossiliferous Miocene marl rests directly
upon these sands. Usually, however, the calcareous sands are separated from
the Miocene by laminated or cross bedded sands and clays often carrying vege-
table remains. At Rock Bluff the calcareous sands have a total thickness of 30
feet. At Alum Bluff, owing to the irregular top surface, the thickness is vari-
able. At one point near the middle of the bluff this stratum is lacking although
elsewhere it has a thickness of 9 to i6 feet.
The cross bedded sands and laminated sands and clays lying above the
calcareous sands are extremely variable in thickness, being not infrequently
absent. They seem in fact merely to occupy irregularities in the top surface of
the calcareous sands. An exposure about 300 feet from the north end of the
bluff gives the following section:
Covered to the top of the hill.
Dark colored alum tasting clays -------------------------------- Jo feet.
Fossiliferous Miocene marl ----------------------------------- 1o feet.
Unconformity.
Laminated clays and sands with plant remains, and blue sands ------ 7 feet.
Irregularity or unconformity.
Calcareous sands ------------- ------------------------------13 feet.
Sloping from the water's edge --------------------------------- 5 feet.
A small stream enters just below this section. At this point is seen sands
with buff colored clay partings, and plant remains, grading at the base into blue
sands, having a total thickness of 8 feet. The greatest thickness observed, 21%/
feet, is at a point near the middle of the bluff. * * The cross bedded sands
here rest directly upon the fossiliferous Chipola beds, the calcareous sand
stratum being as previously stated absent at this point.

In Gadsden County where the fuller's earth beds are worked,
may be seen numerous partial sections of the Alum Bluff formation.
The fuller's earth and the associated gray sands are also seen at
Jackson Bluff and elsewhere on the Ocklocknee River between Gads-
den and Leon Counties.
East of the Ocklocknee River in Wakulla County the Alum Bluff
is believed to be represented by the gray phosphatic and calcareous
stratum which has received the local name of the Sopchoppy lime-
stone, exposures of which are found near the town of Sopchoppy.
The red hills of Leon. Jefferson and Madison Counties with little
doubt represent the Alum Bluff formation. Throughout these coun-
ties remnants of calcareous and phosphatic sandstones are found
scattered through the partially disintegrated surface materials.
Samples of this phosphatic sand rock taken near Tallahassee were
found to contain from 34.3 to 37.47% tri-calcium phosphate. A
sample taken twor:miel(nortl Monticello o Ias







38 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

found to contain 40.45% tri-calcium phosphate. A sample of the
calcareous and phosphatic marl taken from the property of C. A.
Griscom near Lake lamonia in Leon County at a depth of Io feet
below the surface gave the following analysis.

Analysis made by the State Chemist, L. Heimburger, analyst.
Moisture ---------------------------------------- 22.73%
Insoluble matter ----------------------------...------ 43.97%
Phosphoric acid (POs6) 11.56, equivalent to tricalcium phosphate --- 25.27%
Calcium oxide (CaO) 5.06, equivalent to calcium carbonate ------ 9.o3%

In Hamilton County calcareous and phosphatic sands probably
of this formation are found exposed in the sinks and along the
stream beds west and north of Jasper. A limited amount of pebble
phosphate derived from the same formation, is found in the stream
beds at Jennings, near the State line. In Columbia County typical
gray phosphatic and calcareous sands of the Alum Bluff formation
are seen well exposed at Langston sink about four miles northwest
of Lake City. A similar rock containing an abundance of light and
dark colored phosphate pebble is found in Columbia and Bradford
Counties on Olustee Creek near Lulu. Here also in the small
streams tributary to Olustee Creek are found quite considerable sec-
ondary deposits of phosphate pebble derived from this rock. Another
locality in Bradford County in which the phosphatic marls probably
representing the Alum Bluff formation may be seen is the large sink
near Brooker. The following section of this sink is from the
writer's report on phosphates in the Second Annual Report of this
Survey, pp. 239-240.

Section at the sink three miles southeast of Brooker.
13. Covered and sloping 4--------------------------------- 14 feet.
12. Cream or light colored marl full of small shells--..--..- --..... 23V feet.
II. Yellowish sand matrix holding black pebble phosphate --------- 5 feet.
Io. Sandy limestone ledge with fossils ------------------------- % foot.
9. Yellow sand matrix with pebble phosphate ------------------- 4 feet.
8. Concretionary limestone ledge ---------------------------- 1-2 feet.
7. Steel gray colored sand-clay oxidizing yellow ----------------- 5 feet.
6. Concretionary ledge containing pebble phosphate ------------ I foot.
5. Sandy matrix with pebble phosphate ------------------------- 4 feet.
4. Concretionary ledge ------------------------------------ 5 feet.
3. Clayey matrix holding black pebble phosphate ---------------- 5 feet.
2. Concretionary ledge -----------------------------------__ 1 feet.
I. Clayey matrix holding black pebble phosphate ---------------- 4 feet.

.-, Totl de6tfi ,t eater's edge --- ji ,.OAJjfIM.J------ 75 feet.
UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS. 39

The sink at which this section is made is circular in outline and is possibly
200 feet across. The depth of the sink to water level is 75 feet; the depth below
water level has not been determined, although it is reported to be more than
Ioo feet. With the exception of the entrance of a small stream from the east
the sides are almost perpendicular. This stream has cut its channel through to
the hard ledge of stratum No. 4, over which it forms a waterfall. Strata num-
bers one to four of the section stand vertical entirely around the sink. The sands
of numbers five to eight weather brownish in color, forming a conspicuous band
surrounding the sink, except where cut across by the stream. The sands of
number nine and eleven slope slightly from the lack of supporting ledges. The
marl. number twelve, stands vertical or nearly so.
From its considerable thickness the phosphate pebble-bearing formation of
this section may be expected to be found underlying a considerable area in this
part of the State.

In this connection should be mentioned the phosphatic marls and
limestones found on Black Creek in Clay County. This marl is
identical in appearance with the similar phosphatic marls which
underlie the land pebble phosphates. These beds on Black Creek,
however, are regarded as of Miocene age, and correlated from the
invertebrate fossils with the Jacksonville formation.
It may be of interest to note that the Black Creek phosphatic
marls together with secondary pebble deposits derived from them
were at one time worked to a limited extent by the late Governor
N. B. Broward. The development of the deposits, however, was
found not commercially practicable.
The phosphatic beds at Hawthorne which served originally as
the type locality of the Hawthorne formation appear with little
doubt to represent the Alum Bluff formation.* These beds are also
found capping the hills in central Marion County.
In southern Florida the phosphatic marls believed to represent
the Alum Bluff formation are found along Alafia River and thence
east through Hillsboro and Polk Counties to Peace River, and
probably lie comparatively near the surface as far east in Polk
County as the margin of the lake region. In Manatee County these
phosphatic marls are seen along Manatee River and its tributaries.
On Little Sarasota Bay they are exposed at White Beach and on
small streams entering the Gulf.
It is thus evident that the Alum Bluff formation underlies a
large area in Florida. Its great thickness is shown by well records

*Correlation of the Hawthorn Formation, by Thomas Wayland Vaughan
and Charles Wythe Cooke, Journal of the Washington cadem'. of Sciences,
Vol. IV, NQ. ,ppz.250.-2,4 a _gi., p gO in a rom
0 UNIVERSITY OF MICHIGAN







40 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

at Tiger Bay where it is found to be from 275 to 350 feet thick. Its
south-eastward extent is indicated by well samples from Fort Myers
as well as by the secondary deposits of pebble phosphates found
along Coloosahatchee" River and its tributaries.
Lithologically the Alum Bluff formation is extremely variable.
At the type locality the formation consists as already stated chiefly
of calcareous and slightly phosphatic sands. Below the sand is
found shell marl, while above is found cross-bedded sands and clays
containing plant fossils. Elsewhere the formation holds clay beds,
including the workable fuller's earth beds of Florida. In its east-
ward and southward extent the formation consists chiefly of a sandy
phosphatic marl, th1 phosphate being found in the form of pebbles
and probably also in a finely divided condition.
The phosphate pebbles in the formation vary in color from shiny
black to pure white. In size they vary from exceedingly minute
pebbles not larger than sand grains to masses two or three inches in
diameter. In shape they are usually more or less rounded or flat-
tened. The small ones are as a rule nicely rounded, smooth and
shiny, while the large ones are often angular or very imperfectly
rounded. The pebbles, especially the larger ones, when broken are
found to be by no means homogeneous in structure, but include sand
grains, casts of shells and minute phosphate pebbles. In structure
the large pebbles'are essentially the same as the matrix, and it would
seem that the pebbles took their present shape and size at the time
the marl was being accumulated, and that the large ones represent
mud balls made of the material that was then accumulating in the
ocean.
The following analyses are of pebbles from the Alum Bluff for-
mation. Analyses by the State Chemist of Florida.

Analysis of phosphate pebbles washed from the bed rock of the Pierce Phos-
phate Company, Pierce, Florida. Air dried sample.
Moisture -------------------------------------------. .97
Insoluble matter, sand etc. -------------------------- .10- ro.75
Phosphoric acid. 19.41, equivalent to tri-calcium phosphate------ 42.39
Iron and alumina ----------...-----------..---.-_________ o.19
Calcium oxide. 16.79, equivalent to calcium carbonate----------- 38.20
Analysis of phosphate pebble washed from bed rock marl of the Phosphate
Mining Company, near Mulberry, Florida. Air dried sample.
Moisture ---------------------------.--. --------------- 94
Insoluble matter, sand, etc. -------- --------------- 6.1I
[; o r cc 1e uivalent to Maw~ 54-34
I IN M







PEBBLE PHOSPHATE DEPOSITS.


Iron and alumina -------------------------------------- 0.27
Calcium oxide, 7.58, equivalent to calcium carbonate------------17.24
Analysis of phosphate pebble washed from the Alum Bluff marl near Lulu,
Florida. Air dried sample.
Moisture ---------------------------------------- 1.84
Insoluble matter, sand, etc. ------------------------------- 22.46
Phosphoric acid, 26.93, equivalent to tri-calcium phosphate ------- 58.82
Iron and alumina --------------------------------------- 3.02
Calcium oxide, 1.85, equivalent to calcium carbonate------.---.... 4.21
Analysis of phosphate pebble washed from the phosphatic ma.l on Black
Creek, Florida. Air dried sample.
Moisture ---------------------------------------- .88
Insoluble matter, sand, etc --------------------------------- 18.94
Phosphoric acid, 24.45, equivalent to tri-calcium phosphate---- 53.40
Iron and alumina --------------------------------- 0.23
Calcium oxide, 5.07, equivalent to calcium carbonate------------ 11.53

The matrix in which the pebble phosphate is imbedded, is pre-
vailingly a light colored yellow or sandy phosphatic marl, varying
in texture from soft and granular to hard and compact. The sand
consists of clear grains of quartz. The following is an analysis of a
sample of this marl:

Analysis of sample of the bed rock marl from pit No. 5 of the Phosphate
Mining Company, near Mulberry, Florida. Air dried sample.
Moisture ---------------------------------------- 5.03
Insoluble matter, sand, etc. --------------- ---------------- 43.45
Phosphoric acid 6.77, equivalent to tri-calcium phosphate ----..... .79
Iron and alumina -------------------------------------- 0.25
Calcium oxide, 10.41, equivalent to calcium' carbonate----------- 23.64

PLIOCENE.

THE BONE VALLEY FORMATION

The upper Oligocene in the land pebble phosphate section of
southern Florida is succeeded by the Bone Valley formation which
is of late Miocene or early Pliocene age, a part or all of the Miocene
being absent in this part of the State. The lower member of this
formation contains the land pebble phosphate beds. That part of
the formation above the phosphate bed consists chiefly of gray phos-
phatic sands, variable in thickness. At some localities owing to
surface erosion they are almost entirely removed, although else-
where they attain a thickness of thirty feet or more. As a rule the
sands are but slightly indurated. Locally, however, they form a
hard rock with innul re'ab sri cavities whihggigi efranvesicular
:.,., ::. UNIVERSITY OF MICHIGAN







42 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

appearance to the mass. A sample of the rock of this kind was
found to contain 15.56% phosphoric acid (equivalent to 33.9770
tri-calcium phosphate).
At the surface is found as a rule incoherent pale yellow sand,
which although variable has an average thickness of five to ten feet.
It seems probable that these loose surface sands are merely residual
having been derived by disintegration from the phosphatic and for
the most part slightly indurated sands beneath.




















Fig. 2.-View in the Pembroke mine of the Coronet Phosphate Company,
showing the gray more or less indurated phosphatic sands which lie above the
workable phosphate bed. The gradation of the phosphatic sand into the loose
surface sand and soil may be seen in this view.

Although variable from place to place the phosphate beds have
an average thickness of from eight to twelve feet; the maximum
thickness over considerable areas, is possibly from eighteen to twen-
ty feet, although locally, owing to depressions in the bed rock the
phosphate may be much thicker.
The phosphate beds are more or less definitely stratified, the bed-
ding planes being frequently continuous for the full length of the
exposures in the pit, some of which are a half mile or more in extent.
Elsewhere the stratification is irregular and cross bedding is evident.
The phosphate in this formation consists of rounded, flattened or
angplar pieces Qorof rlk9 pebble, togethei)rroithlfragments of bones
c :: UNIVERSITYOF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


and casts of shell. The phosphate rock presents no regularity or
uniformity in size or form and from the same matrix may be washed
pieces varying from I mm. or less to 50 mm. or more in diameter,
or in weight from a few milligrams to several ounces. The larger
pieces when examined under a lens are usually found to contain
grains of sand, small phosphate pebbles and casts of shells imbedded
in a matrix of nearly uniform texture. The small phosphate pebbles
are often well rounded.
In color the phosphate rock is likewise variable. Some of the
pieces are white, while others are tinged with yellow, cream colored,
brown, amber colored, gray and black. A few of the pebbles, es-
pecially the smaller ones, are of uniform texture throughout. With
many of the pebbles, however, the outer layers are more compact
and probably more highly phosphatized than is the interior.

Analysis of phosphate pebbles washed from the phosphate bed at the mine
of the Pierce Phosphate Company, Pierce, Florida. Air-dried sample.
Moisture ---------------------------------------- 1.8
Insoluble matter, sand, etc.--------------------------------- 6.62
Phosphoric acid, 3o.67, equivalent to tri-calcium phosphate------ 66.98
Iron and alumina ---------------------------------- 1.32
Calcium oxide, 3.05, equivalent to calcium carbonate ---------- 6.94
Analysis of phosphate pebbles washed from the phosphate bed at the mine
of the Prairie Pebble Phosphate Company near Mulberry, Florida. Air-dried
sample.
Moisture --------------------- ---------------------1--- .33
Insoluble matter, sand, etc. -------------------------------- 6.87
Phosphoric acid 35.34, equivalent to tri-calcium phosphate--------77.I8
Iron and alumina ------------------------ -------- 0.93
Calcium oxide, 1.39, equivalent to calcium carbonate-------------- 3.16
Analysis of phosphate pebbles washed from the phosphate bed at the mine
of the Phosphate Mining Company, near Mulberry, Florida. Air-dried sample.
Moisture ------------------------------------------ 3.22
Insoluble matter, sand, etc.------------------------------- .35
Phosphoric acid 34.73, equivalent to tri-calcium phosphate--------75.85
Iron and alumina ----.....-----.........---------------.. --. o.28
Calcium oxide, 3.73, equivalent to calcium carbonate-----.----... 8.49

The matrix in which the phosphate pebbles are imbedded in-
cludes chiefly sand, clay, corals, rock fragments, flint pebbles, fossil
bones, shells and petrified wood. The following analysis is of the
matrix including the phosphate pebbles.
S.~O. Lricginal from
... UNIVERSITY OF MICHIGAN







44 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

Analysis of the matrix of the land pebble phosphate. Sample from mine of
the Prairie Pebble Phosphate Company near Mulberry. Air-dried sample.
Moisture --------------------------------------- .78
Insoluble matter, sand, etc.----------------------------------25.18
Phosphoric acid 26.73, equivalent to tri-calcium phosphate---------58.38
Iron and alumina ------------------------------------- 751
Calcium oxide, I.02, equivalent to calcium carbonate ----------- 2.32

The relation of the Bone'Valley formation to the Oligocene de-
posits beneath is that of unconformity throughout. Of the other
Pliocene formations of Florida, the Caloosahatchee and Nashua
marls, it will not be necessary to speak at this time since they lie for
the most part south and east of the phosphate area, and moreover
have been described in the preceding reports of the Survey.

PLEISTOCENE.
The Pleistocene of southern Florida west of the Everglades is
confined to deposits lying near the coast. Of these it will be neces-
sary to consider only those in the stream valleys which hold the river
pebble phosphate, the best known being the Peace Creek beds.
Before continuing the description of the formations holding the
phosphate deposits, however, it may be well to give some further
account of the structure and geologic history of southern Florida.


Fig. 3.-Mining river pebble phosphate on Peace Creek.


Q ,~)OJ


Original from
UNIVERSITY OF MICHIGAN








PEBBLE PHOSPHATE DEPOSITS.


STRUCTURE OF SOUTHERN FLORIDA.
THICKNESS AND SUCCESSION OF FORMATIONS.

With regard to the thickness and succession of the formations
underlying the pebble phosphate deposits in southern Florida, the
best record that is at present available is that which has been ob-
tained through the study of samples from wells drilled at and near
Tiger Bay by the Palmetto Phosphate Company, at Christina by the
Phosphate Mining Company, and at Fort Myers by the Ohio Well
Drilling Company.

Description of samples from well No. 3 of the Palmetto Phosphate Com-
pany, Tiger Bay, Florida.
Depth of sample from the surface.
73 feet. The rock at this depth is a light colored phosphatic marl or limestone.
In texture and appearance it is like the marl which lies beneath the land
pebble phosphates. The phosphate is in the form of smooth, rounded black,
brown, and white pebbles. While this is the prevailing material of the sam-
ple, at least one fragment consists of clear grained quartz, held together by
a phosphatic or calcareous cement and resembling Alum Bluff sands. Acid
test showed this piece to be but slightly if at all calcareous. There are
also some fragments of dark blue hard rock which effervesce but slightly
in acid. No fossils were seen in this sample.
85 feet. This is also a phosphatic marl or limestone. It is similar to the 73-
foot sample except that it is lighter in color, being light gray or nearly
white. The phosphatic pebbles are mostly black in color, the black pebble
in the light colored marl giving a grayish cast to the rock. The hard blue
rock that effervesces scarcely at all in acid is rather more abundant in this
than in the preceding sample. This hard rock also contains black phos-
phate pebbles and it is probable that it is merely a silicified phase of the
marl. Some casts of fossils but no determinable specimens. A considerable
amount of clear grained siliceous sand is seen among the finer material.
150 feet. The material at this depth is also calcareous and phosphatic. The
phosphate pebbles are black or brown and are smooth and rounded. The
rock contains numerous small cavities giving it a porous appearance. Only
one fossil is seen, this being part of a small gastropod.
i6o feet. A phosphatic limestone or marl with some fossil gastropods and bi-
valves preserved as casts. The rock at this depth is in general similar to
the x5o-foot sample. The fossils seem more abundant perhaps because the
sample is larger. The phosphate pebbles are black, brown, and white in
color.
i80 feet. Compact brown, phosphatic limestone. The phosphate pebbles are not
abundant in this limestone and are in the form of small black pebbles im-
bedded in the rock. While the rock is prevailingly compact some porous
fragments are seen. A few broken fossils preserved as casts.
1 )r l nriainal from
.. ... UNIVERSITY OF MICHIGAN








46 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

9go feet. This sample includes compact phosphatic limestone with about equal
admixture of pure white siliceous sand. Whether the sand is from a sand
stratum or from the six-inch cavity found at this depth, or possibly acci-
dentally mixed from the surface, is not known.
195 feet. A sandy, calcareous and phosphatic clay. In water this material falls
to pieces and becomes slippery. In acid it effervesces. The sand is in the
form of clear grained silica. The phosphate is mostly in the form of small
black pebbles. Material is light colored when dry, although slightly bluish
when wet.
200 feet. This material is similar to that at 195 feet although there is perhaps
less phosphate, and the sand is perhaps smaller grained.
205 feet. A gray sandy phosphatic limestone. The calcareous material seems
to predominate, although the rock is rather sandy. The sand grains are
small and well rounded. The phosphate is in the form of very minute dark
specks and the rock possibly also has a phosphatic cement. No fossils seen.
240 feet. A gray sandy phosphatic limestone. The calcareous material seems
to predominate although the rock is rather sandy,.the sand grains are small
and well rounded. The phosphate is in the form of very minute dark specks
and the rock possibly also has a phosphatic cement. No fossils seen in this
material, except some imperfect casts in fragments of a porous limestone
which may have fallen down from a higher stratum. These porous pieces
occur also in the sample at 205 feet.
250 feet. Light colored sandy and phosphatic limestone. The sand grains are
clear silica. The phosphate pebbles are dark colored. A few fragments
of casts of fossils. This rock is not materially different from that at 205
and 240 feet except that it is lighter in color.
255 feet. Bluish gray, sandy, phosphatic limestone together with loose calcar-
eous sand probably representing the ground-up rock. No fossils seen ex-
cept echinoderm spines.

255 to 260 feet. Gray or blue calcareous sandy phosphatic clay. No fossils.
This material is similar to that at 200 feet.
265 feet. Bluish gray sandy phosphatic limestone together with loose calcar-
eous sand probably representing the ground-up rock. No fossils seen except
echinoderm spines.
272 feet. Light colored sandy phosphatic limestone. This is very similar to
the rock above the blue clay. A few fossils including fragments of Pecten.
Also one flattened water-worn pebble of the same material as the rock above.
275 feet. The greater part of the material of this sample is the bluish gray
sandy phosphatic limestone similar to that already described. With this is
found a light colored compact limestone, very slightly phosphatic as shown
by test. The sample also contains several pieces of red iron ore. Of fossils
only a few fragments were seen.

320 feet. Light colored phosphatic and slightly sandy marl or limestone. The
phosphate is in the form of smooth dark pebbles imbedded in the marl.
,The rock is fosi ep although the fos ,lASAEil@ ff g broken.
: :: UNIVERSITY OF MICHIGAN








PEBBLE PHOSPHATE DEPOSITS.


350 feet. Light colored phosphatic marl or limestone more or less sandy. One
small fragment of chalcedony holding cast of shell. A few fossils mostly
broken bivalves and gastropods. The sample includes some bluish gray
sandy phosphatic limestone.

360 feet. Light colored phosphatic sandy marl, also some bluish gray sandy
phosphatic marl or limestone. Some broken fossils are included.
400 feet. Light colored, finely powdered marl or limestone. Fragments of
echinoderm spines are present and other small or broken fossils. A few
phosphatic pebbles are seen, being black and shiny in appearance. A clear
grained quartz sand occurs sparingly. This material is less phosphatic than
that which lies above and resembles the Chattahoochee limestone as seen
at Newland Spring near Falmouth in Suwannee County and near Bass in
Columbia County. Test showed this powdered material to contain a small
amount of phosphate.

4ro feet. Light colored finely powdered marl or limestone. Fragments of echin-
oderm spines are seen, and also other small fossils including a few bryozoa.
This material is similar to that at 400 feet, although there seem to be no
phosphatic pebbles and little if any sand.
420 feet. Light colored, nearly white limestone not so finezi powdered as the
preceding two samples. Fragments of broken shells are abundant. Bryozoa
are numerous. Some foraminifera are present, the mose common being
Orbito'des. This limestone is with little doubt the Ocala. Ttet shows it to be
not phosphatic.

450 feet. The limestone at this depth is practically the same as that at 420
feet. It is light colored or nearly white, fragments of broken shell are
abundant, among which Pecten is recognized. Small foraminifera are nu-
merous, and there are also broken pieces of larger specimens. Bryozoa are
present.
500 feet. Foraminifera abundant, chiefly Orbitoides, including large specimens,
most of which are broken by the drill.

550 feet. Foraminifera abundant. The material is similar to that at 500 feet.
600 feet. At this depth foraminifera are abundant. The predominating form is
Nummuilites. Orbitoides present but not abundant. The sample includes also
some pieces of a soft, granular white marl.
630 feet. Limestone, probably hard and compact, the sample being finely pow-
dered by the drill. Both Nummulites and Orbitoides are present, although
only the small specimens escaped being powdered by the drill. This com-
pact limestone has a slightly brownish cast.

636 feet. Hard compact limestone with brownish cast powdered exceedingly fine
by the drill. Few fossils escaped being powdered up, although some fora-
minifera and bryozoa are present.
650 feet. This sample shows a mixture of finely powdered material with brown-
ish cast together with coarser material from a softer rock. With the coarser
material is included some small pieces of bluish colored chert. Foraminifera
are presepwt :. ), rii l rinal from
-' UNIVERSITY OF MICHIGAN








48 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

665 feet. A limestone breaking into coarse fragments. The predominating fos-
sil is a small flat echinoderm, the internal cavity of which is in most cases
filled with calcite crystals. Foraminifera are also present, although not
numerous.
67o feet. A compact limestone with slightly brownish cast. The same small
flat echinoderm is present, although broken up by the drill, and is not
abundant. Foraminifera are present, although not abundant.
68o feet. A brown limestone rather hard but not very compact. Few if any
fossils are preserved. It is probable that the minute fossils in the rock have
dissolved out, and the cavity partially refilled by calcite crystals. This gives
the rock a porous and partially crystallized appearance and causes it to
break into medium coarse fragments by the drill.

6go feet. The material is chiefly light brown or grayish brown porous lime-
stone partially crystallized, the fossils having been destroyed. With this
is included light colored rock.

710 feet. This sample consists chiefly of soft white limestone in which is in-
cluded a few foraminifera. A limited amount of the harder brownish rock
from the stratum above is present.

720 feet. A light colored, rather hard, although porous, limestone which stems
to be made up of a mass of broken shells and other fragments of fossils.
One small flat echinoderm present, although broken.

740 feet. White granular limestone. Fossils not numerous, although a few
foraminifera are seen; also broken pieces of a small flat echinoderm.
760 feet. Grayish brown limestone, rather hard and partly crystallized. A few
fossils, including a small gastropod.

770 feet. Grayish brown limestone, rather hard and partly crystallized. Few,
if any, fossils.

790 feet. The greater part of the material of this sample is brown or grayish
brown powdered up by the drill medium fine. With this are several large
pieces of ground rock which consists almost entirely of a mass of small
calcite crystals. The sample contains also some light colored material in-
cluding a few foraminifera.
8oo feet. The material of this sample is similar to that of the last. The large
fragments consist chiefly of a mass of small calcite crystals, the mass being
brown in color.

814 feet. The rock at this depth is not unlike that at 8oo feet, although it is
darker in color, being very dark brown, somewhat compact and partly crys-
tallized.
82o feet. A light colored limestone which powders up medium fine in drilling.
Foraminifera present.
830 feet. A light colored limestone which powders up medium fine in drilling.
Foraminifera present, although not abundant.
838 feet. The feeate r of this sample isClitjia aaidtrorather soft limestone;
UNIVERSITY OF MICHIGAN








PEBBLE PHOSPHATE DEPOSITS. 49

there are also some pieces of a white limestone consisting chiefly of broken
fragments. With this are some dark colored pieces which probably scaled off
of the side of the cavity. A small flat echinoderm is present.

Description of samples from well No. 3 of the Palmetto Phosphate Com-
pany, near pit No. i about 24 miles northwest of Tiger Bay.
Depth of sample from the surface.
8 to 16 feet. The material from this depth represents the Bone Valley for-
mation.

3o to 40 feet. Yellow sandy and clayey phosphatic marl. The phosphate is
chiefly in the form of smooth rounded light or dark pebbles. Smooth silic-
eous pebbles are also present. This material represents the "bed rock,"
which is the Alum Bluff formation.

40 to 50 feet. Light colored marl with some bluish calcareous clays and pebble
phosphate.

50 to 6o feet. Gray phosphatic sandy marl.
6o to go feet. Light colored limestone, including some phosphate pebbles and
broken pieces of chert.

go to o05 feet. Light colored limestone, light and dark phosphate pebbles and
broken pieces of chert.

115 to 125 feet. Phophate pebbles and pieces of broken chert, and light col-
ered limestone.

141 feet. A rather hard light brown limestone, including phosphate pebbles and
some light colored limestone and broken pieces of chert.
143 feet. Porous limestone and marl with an abundance of black phosphate
pebbles.
160 feet. Light colored porous limestone or marl with black phosphate pebbles.

170 to 9go feet. Rather hard brownish limestone, with some phosphate pebbles
and occasional casts of shells.
200oo to 210 feet. Rather hard, light colored or gray sandy phosphatic limestone.
The phosphate is chiefly in the form of minute black pebbles.
218 to 223 feet. Slightly greenish sandy phosphatic and calcareous clays. This
clay is much like a part of the sample obtained from well No. 3 at 255 to
260 feet.

223 to 226 feet. Light colored or gray phosphatic limestone or marl very simi-
lar to the rock at 210 feet.
226 to 252 feet. Slight greenish sandy phosphatic clay, much like that at 218
to 223 feet.

253 to 260 feet. The material at this depth consists chiefly of a greenish, very
sandy phosphatic marl. The fossils observed include several sharks' teeth
and casts of shells. Alsoteeth of the ray. In addition to the greenish marl,
is found some f ght, cporo dliniretLt or marl ~ iil airsl
3








50 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

275 to 290 feet. This sample consists in part of greenish sandy phosphatic marl
similar to that at 253 and 260 feet, containing teeth of sharks and rays. The
sample also includes a light colored nearly white limestone, containing small
shells, bryozoa and spines of echinoderms.

300 to 320 feet. Light colored or white granular limestone including broken
shells, spines of echinoderms, bryozoa and other fossils.

330 feet. Hard brownish limestone powdered fine in drilling.

337 and 350 feet. Light colored or white granular porous limestone, shells pre-
served as broken fragments.

360 to 530 feet. Ocala limestone consisting of a mass of broken shells, among
which Orbitoides predominates.

540 to 560 feet. Ocala limestone in which Nummulites as well as Orbitoides are
abundant.

570 and 580 feet. Echinoderm horizon, the samples consisting almost wholly
of a small echinoderm.

590 feet. Rather hard limestone with brownish cast. Nummulites and Orbitoi-
des present although not abundant.

6oo feet. This sample, like those at 570 and 580 feet, consists of a mass of
small echinoderms.
620 to 660 feet. The samples throughout this interval consist chiefly of a hard
limestone of brownish color which is powdered fine by the drill.

670 feet. This sample consists largely of very small brownish calcite crystals.
After the well had been completed and allowed to stand for some time,
8 to to bushels of this material was pumped from the well, having been
carried into the well from the cavity in the rock.

68o to 740 feet. The samples throughout this interval are from a hard lime-
stone, brownish in color, which as a rule is powdered rather fine by the drill.

750 and 770 feet. Small calcite crystals which were pumped from cavities.
Description of samples from the well of the Phosphate Mining Company.
Well located at Christina, Florida. Depth of well 8oo feet.
Depth of sample from the surface.

ioo feet. The rock at this depth consists of sand with slightly greenish tinge
together with fragments of a light colored marl containing small black
phosphate pebbles.

120 to 300 feet. Samples at twenty-foot intervals. The rock throughout this
depth is a light colored limestone having an appearance of a mass of broken
fragments.

320 to 460 feet. samples at twenty-foot intervals. The rock throughout this
interval is a light colored limestone containing an abundance of foramin-
ifera.
48p ard 520 fet.; (tigihtcL ored granular lirm7'sF lI from
.. .. UNIVERSITY OF MICHIGAN








PEBBLE PHOSPHATE DEPOSITS.


540 feet. Light colored limestone with small, flat echinoderms.
560 to 680 feet, samples at twenty-foot intervals. Light to brownish colored
limestones.
8oo feet. Light colored granular limestone.

Description of samples from the city well, Ft. Myers, Florida, drilled 1914.
driller Ohio Hiell Drilling Company; Jacksonville, Florida. Size To and 8 inches:
casing io-inch, 14 feet; 8-inch. 203 feet; principal water supply 875 feet; flowing
yields 650 gallons per minute, depth 950 feet; in charge of drilling. G. P. Peppard.
Depth of sample from the surface.
200 feet. Light colored limestone with fragments of fossils, also some sand
and dark, shiny phosphate pebble. Fossils include bryozoa, broken shell
fragments, etc.
210 feet. Much the same rock. Shark's tooth, some phosphate pebble, broken
shells, some echinoderm spines and many bryozoa.
220 feet. Similar light colored limestone. Some fine black phosphate pebble
imbedded in the. rock.
230 feet. Similar light colored limestone.
280 feet. Similar light limestone consisting of broken shell fragments together
with fragments of rock containing minute black phosphate pebble.

300 feet. Similar light colored limestone consisting of broken fragments of dif-
ferent shells together with some pieces of hard, dark colored rock.

320 feet. Similar light colored limestone consisting of shell fragments.
360 feet. A similar light colored limestone containing also small shiny black
phosphate pebbles.

340 feet. Similar light colored limestone with an abundance of small shiny
black phosphate pebbles.
380 feet. Similar light colored limestone consisting of a mass of broken shell
fragments, rather more finely broken up than the preceding. Phosphate
pebbles somewhat less abundant than in last sample.

400 feet. Similar light colored limestone consisting of a mass of shell fragments
broken up finely.

42o feet. Similar light colored limestone, some phosphate pebble as in preceding.
44o feet. Similar light colored limestone, including phosphate pebble, also one
small oyster shell.
460 feet. Similar light colored limestone, although not so finely broken up and
including pieces of rock with the small phosphate pebbles imbedded.
480 feet. Buff calcareous clay, some phosphate pebble and some shell fragments.

500 feet. Light colored limestone consisting of shell fragments with an abun-
dance of black phosphate pebble and with small fragments of the sandy
marl with slightly, g8re Qae ) or. .rgl nai rromT
UNIVERSITY OF MICHIGAN







52 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

52o feet. A somewhat harder limestone, containing, however, phosphate pebble.
54o feet. Limestone similar to that at 520. This limestone is not so light in
color and does not contain so many shell fragments as the limestone above
320 feet.
60o feet. Very fine, siliceous and calcareous sand containing minute black
phosphate pebble.
640 feet. Same as 6oo.
68o feet. Similar finely powdered material containing, however, less quartz
sand.
720 feet. Limestone with slightly brownish color and finely powdered by the
drill.
760 feet. Finely powdered calcareous material similar to that at 6oo feet.
8oo feet. Light colored limestone consisting of a mass of broken fossils.
840 feet. Same as at 800 feet.
88o feet. Same as at 8oo feet.
900 feet. Finely powdered rock including fine quartz sand much like that at
6oo feet.
950 feet. Limestone consisting of a mass of broken fossils.

The thickness and succession of formations underlying the peb-
ble phosphate beds as indicated by these records is as follows:
I. Bone Valley formation. The thickness of this formation is
not shown by the samples, but the formation is always comparative-
ly thin and when mined is worked to the bottom where it rests upon
the phosphatic marl known as the "bed rock."
2. Beneath the land pebble phosphate beginning with the "bed
rock" as the term is used in the mining operations, is found a suc-
cession of phosphatic marls extending at Tiger Bay to a depth of
about 360 feet. At Christina, about 16 miles north of Tiger Bay
the formation is not more than ioo feet thick, while at Fort Myers
about 70 miles south of Tiger Bay it is at least 600 feet thick. The
material throughout this whole thickness, while by no means uni-
form, apparently represents a single geologic formation which is
locally variable, the phosphate pebbles which occur throughout the
whole thickness are black, brown or white in color and are rounded,
smooth and shiny. The pebble is imbedded in a marl, the prevailing
color of which is light buff or grayish. The marl is throughout more
or less sandy, so much that in some of the samples it becomes almost
a calcareous sandstone Locally the n riq fin his marl has be-
S- OO UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


come compact and close gained, probably in the form of small
boulders which are broken up in drilling. Boulders of this type may
be either calcareous or flinty. While fossils are not abundant it is
probable that this phosphatic marl is of Upper Oligocene age. The
marl is with little doubt the parent formation from which by re-
working and concentration the pebble phosphate conglomerate of
the Bone Valley formation was formed.
3. Beneath the phosphatic marl is found limestone in which all
the wells terminate. At Tiger Bay the first 50 feet of this limestone,
360 to 410 feet from the surface, consists largely of a mass of small
pieces having the appearance of broken fragments of fossils. Below
410 feet the prevailing phase is a light colored limestone, often gran-
ular in appearance. containing 'many foraminifera. Occasional
strata are found which are hard and compact and usually of a brown-
ish-color, the material being finely powdered by the drill. Locally
also flint masses occur which represent silicified limestone and may
or may not be encountered in any particular well. Locally also the
limestone is partially crystallized, this phase being due to solu-
tion and redeposition by underground water. At Christina the
limestone beneath the marl is reached at a depth of about 120 feet,
and foraminifera become abundant at about 320 feet. At Fort
Myers the non-phosphatic limestones are reached at about 700 feet.
The rock in which foraminifera are abundant is believed to repre-
sent the Ocala limestone and it may be that all of the non-phosphatic
limestones beneath the phosphatic marl are of that formation.
The generalized sketch (fig. 4) has been drawn to illustrate
the geologic structure as found on a line through the State from
north to south passing through the pebble and hard rock phosphate
section. The relation of the phosphate deposits to the underlying
formations is well shown by this sketch. The foundation rock is
the Ocala limestone which comes to the surface over a limited area
in the central peninsula section. The hard rock phosphate deposit
rests directly upon this limestone. To the south and also to the
north the limestone dips below the surface and disappears beneath
the later formations. The upper Oligocene formations lie upon the
Ocala limestone in extreme northern and southern Florida. The
Bone Valley formation, including the land pebble phosphate, in turn
rests upon these upper Oligocene deposits. In extreme southern
Florida Pliocene and Pleistocene marls and sands form the surface
materials. ( ~ Ori:iinal from
... : UNIVERSITY OF MICHIGAN







54 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

GEOLOGIC HISTORY OF SOUTHERN FLORIDA.
If the areal and structural geology has been correctly described,
the geologic history of southern Florida may be readily interpreted,
so far at least as it affects the problem of the formation of the phos-
phate deposits. Several periods of deposition are recognized sepa-
rated by more or less well marked intervals of emergence and
erosion.

PERIOD OF DEPOSITION OF LATE EOCENE SEDIMENTS

The Ocala limestone which underlies the Florida peninsula and
is probably of Eocene age is of marine origin having accumulated
in sea water of medium depth, and under conditions that were uni-
form over large areas, and for a long period of time.*

POST-EOCENE PERIOD OF EMERGENCE AND EROSION

The conditions which permitted the accumulation of the Ocala
formation continued probably into the Oligocene, and was then fol-
lowed by a period of emergence during which the Florida plateau
was lifted above sea level, becoming dry land. It is difficult to de-
termine the extent of this uplift. That dry land areas existed, how-
ever, is shown by the fact that the top surface of the Ocala limestone
is irregular having been worn uneven by erosion. Moreover, the
earliest of the upper Oligocene deposits that accumulated in the vi-
cinity of Tampa contain a very conspicuous element of land and
fresh water fauna, particularly mollusks,t thus showing that the
shore line at that time was at no great distance from that locality.

PERIOD OF DEPOSITION OF UPPER OLIGOCENE SEDIMENTS

A widespread submergence permitted the extension of the sea
over large areas during upper Oligocene that for a time had been
dry land. The deposits that accumulated in Florida at the time of
this submergence include the Chattahoochee, Tampa and Alum Bluff
formations, the characteristics and extent of which have already been
described. The distribution of these formations is such as to leave

*Vaughan, T. Wayland, A Contribution to the Geologic History of the
Floridian Plateau, Carnegie Institution of Washington, Publication No. 133,
pp. 99-185, 1910.
tDall, W. H., Contribution to the Tartiary fauna of Florida. Wag. Free
Inst. Sci. Trans.Vl. (V li, P.3-4, 1890; U. S. NSir.ijmaJ Bgkln9go, pp. 18-19, 1915.
.- : .,: UNIVERSITY OF MICHIGAN






PEBBLE PHOSPHATE DEPOSITS.


little doubt, but that at the time of maximum depression the whole
of the peninsula was submerged.

POST-OLIGOCENE PERIOD OF EMERGENCE AND EROSION
The upper Oligocene time was followed by a period of emer-
gence which evidently was very extensive bringing much of the
present peninsula above water level. Evidence of this emergence is
found in the fact that the top surface of the upper Oligocene deposit
is irregular indicating surface erosion. Moreover, the succeeding
formations without exception where the contact is observed, rest un-
conformably upon the upper Oligocene. A partial re-submergence of
Florida occurred during Miocene-time as is shown by thefact that
marine Miocene formations are found over quite extensive areas in
western Florida, being exposed along the Choctawhatchee, Apalach-
icola and Ocklocknee rivers. Miocene deposits are also found along
the Atlantic slope at Jacksonville in Duval County and at Rock
Springs in Orange County, as well as on Black Creek in Clay County.
As already noted, however, the Miocene formations, unless the Bone
Valley formation itself is Miocene, are not found in the land pebble
phosphate section of the State, from which it is inferred that this
section was dry land during most, if not all of the Miocene period.

PERIOD OF DEPOSITION OF PLIOCENE SEDIMENTS
It was not until near the close of the Miocene or perhaps early
in the Pliocene that the area in southern Florida in which is found
the pebble phosphate deposits was again submerged. The marine
formations that accumulated in Florida during the Pliocene include
in addition to the Bone Valley formation, which contains the land
pebble phosphates, the Caloosahatchee and Nashua marls. That the
submergence at this time was extensive is shown by the wide distri-
bution of these formations in southern and eastern Florida.
The Pliocene period was closed in Florida by an uplift, which if
of no great extent vertically, was at least sufficient to add materially
to the land area of the peninsula.

CHANGES IN LEVEL DURING PLEISTOCENE TIME
With the events of Pleistocene time, we are not so directly con-
cerned in this paper. It is apparent, however, that appreciable
changes in level occurred during the Pleistocene, to some of which
S i Ori:ginal from
... :! *UNIVERSITY OF MICHIGAN






56 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

it will be necessary to refer. Early Pleistocene deposits are found
fringing the Gulf shore of southern Florida and the Atlantic border
of eastern Florida. Marine Pleistocene shell beds are found on Six-
Mile Creek in Hillsboro County; near Bradentown, and at North
Creek in Manatee County; on the Caloosahatchee River and gener-
ally over the Everglades, and thence north along the Atlantic Coast.
Following the deposition of these early Pleistocene shell marls, the
peninsula was lifted probably by successive minor oscillations to a
level somewhat above its present elevation.
Finally, a slight depression probably during the late Pleistocene,
brought the peninsula to its present level. Undoubted evidence of
this late Pleistocene depression is found in the fact, long ago noted
by Shaler,* that the important harbors of Florida, among which
may be mentioned Charlotte Harbor and Tampa Bay, represent
flooded river valleys. Additional confirmatory evidence is derived
from many sources. Captain O. N. Bie of the United States Engin-
eering Corps reports that while dredging the channel to Tampa
there was encountered about seven miles below Tampa at a depth of
20 feet a mass of cypress limbs and branches, indicating probably the
location of a Pleistocene cypress swamp which existed at a time
when the land area stood not less than 25 or 30 feet higher than at
present. On the Florida Keys Mr. W. J. Krome, Construction En-
gineer of the Florida East Coast Extension, reports the existence of
swamp and peat deposits at places along the Keys at a depth beneath
the marls of as much as 20 feet.

SUMMARY OF THE GEOLOGIC HISTORY
By way of summary of that part of the geologic history of
southern Florida which specially concerns the origin of the pebble
phosphates, it may be well to repeat, that during the late Oligocene
time there accumulated over a part of Florida the great phosphatic
marl known to the miners of pebble phosphate as the "bed rock."
The phosphate in this marl existed in the form of pebbles of various
sizes, shapes, and colors, and probably also as soft, or finely divided
phosphate. Following the deposition of this marl a very large part
of Florida became dry land. The marls were thus subjected to sur-
face erosion, by which the top surface came to present the irregulari-

*Shaler, N. S., The Geological History of Harbors. U. S. Geol. Sur. 13th
Ann. Rept., pt. 2, pp. 190-192, I893.
S. Original from
... :! UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


ties characteristic of and common to exposed land surfaces. This
period of emergence and erosion continued apparently during the
greater part, if not all of the Miocene period. Near the close of the
Miocene or early in the Pliocene came a period of submergence per-
mitting the sea to cover large areas of Florida that had previously
been-dry land.. In connection with and following this Pliocene sub-
mergence was accumulated the Bone Valley formation, the first or
lowest member of which holds the land pebble phosphates. With
these facts regarding the geologic history of southern Florida in
mind it becomes possible to understand and account for the pebble
phosphate deposits, and to explain many of the peculiarities of the
formation.

THE LAND PEBBLE PHOSPHATE DEPOSITS

\ith regard to the genesis of the land pebble phosphate deposits
Eldridge in 1893 wrote as follows:*

The resemblances in texture, color, fossil casts, and general appearance
which the pebbles of this deposit occasionally bear to the hard-rock type are in
a measure suggestive of their derivation from a limestone of pre-Pliocene times
possibly older Miocene. On the other hand the prevailing white color, the often
earthy appearance of the fresh surfaces, the lower percentage in phosphate of
lime, the softness and the condition of preservation of included fossils suggest
their origin from a marl or at least a very earthy friable limestone. In either
case they may be the rolled fragments of pre-existing beds, a possibility enhanced
by the character of their matrix and by the occasional presence of well-rounded,
white quartz pebbles.

Shaler was of the opinion that the land pebble phosphates of
Florida should be placed in the category of Residual Ablation De-
posits. He says, as quoted by Eldridge (1. c.) :

In the case of the pebble phosphates it is evident that the fragments have
been to a certain extent swept from the uplands into the valleys. Thus on the
low divides between the Alafia river district and the neighboring portions of
Florida, the phosphatic pebbles may form but a thin layer or be altogether want-
ing, while in the valleys the accumulations of pebbly material may have a thick-
ness of 30 feet or more. This segregative process has probably in part been
accomplished by the work of the streams themselves, but it is in my opinion
mainly due to the action of the sea during the time or times when this part of
the peninsula has sunk beneath and risen above the ocean level. The action of
the sea in this concentrative work appears to be indicated by the frequent occur-

*A Preliminary Sketch of the Phosphates of Florida, by George H. Eldridge.
Am. Inst. Min. Eng. Trans .xxi, pp.96-231, 1893. Original from
UNIVERSITY OF MICHIGAN






58 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

rence of shark's teeth and other remains of marine forms in a state of preser-
vation which seems to me to clearly indicate that they were formed since the
phosphatic pebbles took their shape. They appear indeed to be mere accidental
and exceedingly modern elements of the deposit. They have evidently experi-
enced no such attrition as has affected the pebbles themselves.

Dr. W. H. Dall regarded these deposits as of marine origin and
of Pliocene age.* Messrs. Matson and Clapp, however, while rec-
ognizing the possible estuarine origin of a part of the beds, were
inclined to regard the Bone Valley formation as chiefly fluviatile.f
Aside from the papers referred to above few serious at-
tempts have been made to account for the origin of the land pebble
phosphates. This is in marked contrast to the literature on the hard
rock phosphates, for the origin of which a multiplicity of conflicting
and often fantastic theories were offered during the early days of
mining. With regard to the fluviatile origin of the beds, while the
deposits were clearly accumulated in shallow water, it has seemed to
the writer that the characteristics of the formation as given in the
following pages indicate estuarine or shallow water marine deposits.

THE LAND PEBBLE PHOSPHATE BED A PEBBLE CONGLOMERATE
ACCUMULATED UNDER MARINE OR ESTUARINE
CONDITIONS.
When the sea advances across an area that previously had been
dry land the first deposits accumulated are of local origin, being de-
rived from the residual materials of the land surface, together with
inclusions, fragments, and pieces broken or washed from the rock
beneath. The material thus accumulated is usually coarse in texture,
and in that case forms a conglomerate. If subsidence continues the
conglomerate layer is followed by sediments that, having been trans-
ported a greater distance, and lodged in deeper waters, are finer,
more uniform in texture, and more thoroughly assorted, than those
first deposited. The stratum of coarse material at the base of a for-
mation accumulated under these conditions is known as a basal con-
glomerate.
If the geologic history of southern Florida has been correctly
interpreted, the sea, probably in early Pliocene time, advanced
across the upper Oligocene phosphatic marl, and in doing so accumu-
alted first of all a conglomerate layer, the materials of which, de-

*Neocene of North America. U. S. Geol. Surv. Bull. 84, pp. 141-142, 1892.
tFla. Geol. Sorv. ASeco annual Report, Ipri S&aOfIaoq.
; UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


rived chiefly from the marl beneath consisted of phosphate pebble,
pieces of the marl, casts of invertebrates, sand, clay, worn bones and
teeth. This conglomerate, which is the land pebble phosphate bed,
makes up the basal member of the Bone Valley formation. That
part of the formation above the conglomerate includes the sands of
the overburden. These as previously noted are as a rule phosphatic,
although the phosphate is either in a finely divided form or is the
cementing material in the sand, little or no phosphate pebble or
other coarse material being included in this part of the formation.
The change from the conglomerate to the sands is rather abrupt but
is not marked by evidence of a time break.
It is usually found that the coarse material of a conglomerate,
grades to finer material above. This is true of the pebble phosphate
conglomerate which as already stated grades into the sands above.
Within the bed itself, however, it is usually found that the coarsest
part of the conglomerate is that near the top. The assorting of the
materials near the base is also frequently less complete than near the
top of the bed. This seemingly exceptional feature finds its expla-
nation without doubt, in the conditions under which the beds ac-
cumulated.











Fig. 5.-The accompanying sketch has been prepared to illustrate conditions
that may have and probably did exist in this region at the time the phosphate
bed was being formed. The sketch is drawn to represent a stage in the ad-
vance of a sea across a land surface, the country rock of which, a marl, pre-
sents the numerous minor irregularities characteristic of a marl or limestone
country which for a time has been subjected to sub-areal erosion. The land
area, not yet invaded by the sea is shown at () ; the phosphate bed that is being
accumulated, shown at (2); the bed rock marl, some parts of which still project
above sea level, shown by (3). That part of the land area not yet reached by
the sea retains its usual covering of soil and residual material. From that part
which has been invaded by the sea, however, the soil and loose materials have
been shifted about, washed and more or less perfectly sorted. The organic
matter of the soil has largely been removed, while the clays, sands and coarse
fragments are dropped iti t def espions. Original from
l C UNIVERSITY OF MICHIGAN







60 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

A conglomerate partakes of the characteristics of the rock from
which it is derived. In regions where the country rock is resistant,
and especially where it is shattered by the action of frost, the resid-
ual material on the hillsides and in the stream beds is likely to
contain a large proportion of coarse rock fragments. The rock
from which the conglomerate of the pebble phosphate beds was de-
rived, however, is for the most part a rather soft marl with a vary-
ing amount of sand, clay and phosphate pebble. The residual ma-
terial that accumulates when a rock of this character is submitted
to a sub-areal erosion consists, as may be seen in sections where this
formation is now the country rock, chiefly of sand and clay, there
being only a limited amount of phosphate pebble in the sub-soil.
Under these conditions it is not surprising to find that the materials
first accumulated in the depressions contain frequently a considerable
proportion of sand and clay, while that which follows may include
a larger amount of phosphate pebble and rock fragments washed
or broken by the waves or streams from the bed rock. However,
as each depression is differently located with regard to the sweep of
waves and the force of the currents, endless variations in the de-
posits accumulated must be expected. When the sea but partly
covers the land and is shallow, obviously the force of the waves is
slight. If depression continues until a larger part of the land is
submerged, the waves gain a greater sweep. With progressing
submergence, there comes a point of maximum effectiveness of wave
action in washing and moving materials. Finally, however, the
shore line is removed to such a distance that the phosphate pebble
are no longer carried in quantities sufficient to make up workable
beds. In other words the' phosphate beds then give place to the
phosphatic sands of the overburden.
Moreover, it is quite possible that the submergence of the land
area was attended by minor oscillations in level. It is not improbable
for instance, that following partial submergence and the accumula-
tion of deposits near the shore line, the land area may have been
slightly elevated. If so, the shore line was changed, and the streams
of the adjacent land area rejuvenated. The phosphate deposits that
had accumulated near the former shore line were then reworked,
the finer materials removed, and the coarse rock reaccumulated in
shallow water near the shore, the deposits resulting from this second
concentration being more thoroughly washed and richer in pebble
phosphate thanwere theqbds first depos-(idinalfrnseems quite pos-
; :.,: ::UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


sible that to some such slight oscillations in level accompanied by
the reworking of the shore deposits may be due the accumulation of
the conglomerate to a workable depth over the limited area in which
the bed is minable.
That such minor oscillations occurred, is not only in the nature
of the case probable, but is possibly indicated by an unconformity
found in the phosphate bed, an account of which is given in the para-
graph which follows.

STRUCTURAL FEATURES AND LOCAL DETAILS IN THE PHOS-
PHATE BED, THE OVERBURDEN AND THE BED ROCK.

If the view as to the origin of the phosphate deposits here pre-
sented is correct it should be possible to apply the principles involved
in the explanation of some of the many irregularities in the phos-
phate beds, and in doing so to further test the validity of the theory
itself.
UNCONFORMITY WITHIN THE PHOSPHATE BED.

The northernmost plant in the land pebble section at the present
time is that of the Coronet Phosphate Company located in Hillsboro
County three miles southeast of Plant City. The following sections
were observed in pits Nos. I and 2 of this plant.

Section in pit No. i, Coronet Phosphate Company.
I. Pale yellow incoherent sand ------------------------ 4 feet.
2. Gray indurated sand ------------------------------------ 4 feet.
3 Conglomerate of phosphate pebble, bone fragments, water
worn flints and pebbles --------------------------- to 11/ feet.
4. Buff yellow and olive green clay with phosphate pebble ------ 2 to 5 feet.
5. Yellow clay and marl, "bed rock" at bottom of pit.
Section in pit No. 2, Coronet Phosphate Company.
r. Incoherent sand ---------------------------------------- 6 feet.
2. Indurated sands --------------------------------- 2 feet.
3. Conglomerate of phosphate pebble, bone fragments, water worn
flints and coral ------------------------------------- 14 feet.
4 Buff yellow and olive green clay matrix in which phosphate pebble
is imbedded --------------------------------------- 5 feet.

The superficial pale yellow sand is of medium fine texture and is
non-fossiliferous. The indurated gray sand is also non-fossiliferous
in the upper part. Towards the base, however, this sand grades into
the conglomerate previously mentioned, the lower one to one and
S one-half feet being a very rich phosphate conglomerate. (No. 3 of
the sections). ,. ,, I Origrinal from
.. .. UNIVERSITY OF MICHIGAN







62 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

Evidence of an unconformity is seen in these pits between Nos.
3 and 4 of the sections. The material above the break is a coarse
conglomerate consisting of phosphate pebble, water-worn flint peb-
ble, bone fragments and worn corals. Immediately on the contact
line is found a considerable amount of worn coral, some pieces of
which were estimated to weigh as much as eight or ten pounds.
At no other place in the phosphate beds are worn corals so numerous
or so large as at this locality.
The phosphate matrix of No. 4 beneath this break contains much
clay and is chiefly of a bluish color which upon exposure oxidizes
to a light buff yellow. Occasional bones and flint pebbles are found
also in this part of the formation. The water worn corals, however,
were not observed below the unconformity. That part of the phos-
phate matrix below the break in deposition contains also much clay
and many rounded pieces of soft phosphate while that above the
unconformity contains hard pebble rock only.
This unconformity may be purely local and due merely to the ac-
tion of tides or of streams in the shallow waters which after wash-
ing out a part of the phosphate bed, reaccumulated coarser material
in the depression. It seems probable, however, that the uncon-
formity, together with the observed fact that coarse conglomerate















Fig 6.-Section in pit No. I of the Coronet Phosphate Company showing
unconformity in the phosphate bed. (i) Soil and incoherent surface sand.
(2) Somewhat indurated phosphatic gray sands, grading below into (3) a
coarse conglomerate of phosphate pebble, worn bones, flint pebbles and silicified
corals. (4) Phosphate bed containing sand, clay and phosphate pebble. .5) Bed
rock marl. An unconformity is found in this section within the ph ,sphate bed
between (3) and (4), as well as at the chase of the phosphate bed between (4)
n(1OC UNIVERSITY OF MICHIGAN
i.: : .',.. ':, ( "' '' r,: na f ro







PEBBLE PHOSPHATE DEPOSITS.


lies near the top of the phosphate beds throughout the whole field,
indicates a change of conditions during the time of the deposition of
the phosphate beds, a slight uplift having brought about a second
concentration resulting in deposits of greater thickness and richer
in the percentage of pebble phosphate to the matrix than would
otherwise would have accumulated over this area.
In pit No. 3 of the Prairie Pebble Phosphate Company near Mul-
berry the following section was observed:
i. Incoherent sand ------------------------------------- 2 to 4 feet
2. 'Indurated gray sand grading below into phosphate matrix----- 12 to 16 feet
3. Workable phosphate stratum -------------------------- o to 12 feet
4. Yellow clay marl, "bed rock" (exposed) -------------------- 5 feet

The following section was observed in the pit of the Medulla
Phosphate Company at Christina:
x. Incoherent pale yellow sand and soil --------------------- 2 to 5 feet
2. Gray sand, iron stained near surface ------------------------ 8 feet
3. Phosphate bearing matrix ------------------------------- 12 to 20 feet
4. Yellow clayey marl, "bed rock" (exposed) ------------------- 4 feet

The gray sands of the overburden pass gradually into the work-
able phosphate bed, the upper one or two feet of which is a coarse
pebble conglomerate, while that beneath contains considerable clay.
The stratification lines in this pit are well marked.

IRREGULARITIES IN THE TOP SURFACE OF THE BED ROCK.

That the top surface of the bed rock is extremely irregular is a
fact observed in practically all pits that have been worked, the rock
presenting in fact all of the irregularities of an original land sur-
face. This is to be expected since it is believed that the bed rock
marl was subjected to erosion for a time previous to the deposition
of the phosphate.

ABSENCE OF FORMATIONS OF THE MIOCENE PERIOD.

The bed rock marl is believed as has already been noted to rep-
resent deposits accumulated during the upper Oligocene time. The
formation holding the land pebble phosphates on the other hand was
formed as shown by the fossils which it contained either very late
in the Miocene period or more probably early in the Pliocene. There
is thus an-almopt if4oqoi npcolp te absence Uof F1 1 nattins.
is.thus....- U UNIVERSITY OF MICHIA







64 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

This fact is in accordance with the belief that this area was dry
land during the greater part or all of the Miocene period.

LACK OF CONTINUITY OF. THE PHOSPHATE BEDS.

From the prospecting records it seems probable that the con-
glomerate representing the phosphate bed is not continuous over the
whole area. This is doubtless true and is certainly to be expected.
The old land surface represented by the bed rock being irregular, it
is apparent that when submerged the accumulation of the phosphate
conglomerate would take place in the original valleys and depres-
sions while the higher lands were yet submerged. The materials
of the phosphate stratum are derived not from the marl immediately
beneath, since that particular spot was quickly covered by the ac-
cumulation of debris, but rather from nearby marls that were as
yet exposed to the force of the waves or were subjected to the action
of stream currents. It is to be expected, therefore, that there are
spots and doubtless considerable areas over which a pebble con-
glomerate of sufficient thickness to be workable did not accumulate.

VARIATIONS IN THE VERTICAL SECTION.
The phosphate conglomerate is itself by no means uniform in
vertical section. The variations, however, are such as are of com-
mon occurrence in shallow water deposits. If, as is here assumed,
the phosphate beds were accumulated at the time of the advance of
the sea across the land surface, it is apparent that the conditions of
deposition including depth of the water, force of the waves, and
proximity to land must have 'been constantly changing, thus account-
ing for variations in the vertical section.

VARIATION IN THE BED WHEN TRACED LATERALLY.
If the lack of continuity of the beds, as well as their variation in
vertical section, has been accounted for, little in addition need be
said in regard to their variation when followed laterally, since such
variations follow as a matter of course.

VARIATION IN PERCENTAGE OF THE PHOSPHATE PEBBLE TO MATRIX.
Under the theory here proposed it requires no special explana-
tion to appreciate reasons for extreme variation in the percentage
of phosphate pebt1l 4itematrix. The fiacttihaltftheimaterials of the
S' 'UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


beds have been subjected to the sorting power of water is of itself
sufficient to account for such variations as occur.

VARIATION IN THICKNESS OF THE PEBBLE CONGLOMERATE.
The thickness of the pebble conglomerate constantly varies from
place to place. This variation of thickness is due first of all to the
irregularities of the bed rock. The top surface of the pebble phos-
phate stratim,' where it grades into the overlying sands is as would
naturally be expected much more nearly uniform than is the bottom
of the stratum which necessarily conforms to the irregularities of the
bed rock.
COLOR OF THE PEBBLE ROCK.
The pebble phosphate in the "bed rock" marl is black, amber,
Brown, gray or white, while the rock itself is prevailingly yellow.
Accordingly the pebble conglomerate derived from the "bed rock"
presents a similar range of variation in color.

VARIATION IN THE GRADE OF ROCK.
Of the many variations in the phosphate beds none is more per-
plexing nor of more direct concern to the phosphate operators than
that of variation in the grade of rock. The variation in grade is
doubtless influenced by many factors some of which as least may be
accounted for. First of all it must be remembered that deposits that
have accumulated through the agency of water are necessarily more
or less assorted, and this is true whether the material is accumulated
by surface streams or by wave action, or by both agencies combined.
This partial sorting of materials while the pebble phosphate stratum
is being accumulated would almost necessarily result in variation
from place to place in the grade of the rock.
There is moreover another factor involved in this problem that
as yet has not been specially mentioned, but which affects the grade
of rock and also helps to account for some of the other variations
in the beds. From the generalized geologic section given on page
53 it will be seen that the Bone Valley formation cuts across the
eroded bed rock. From this it appears that the pebble phosphates
are derived not from any particular stratum in the bed rock but
from many different strata. It is not to be expected that the pebble
from different strata in the bed rock are of the same grade. It thus
follows that the gradenoi(r iJ y any partic ular'-ftll
UNIEI I MIC







66 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

be influenced by the grade of the pebble in the bed rock stratum from
which it chiefly received its supply of pebble, the grade being fur-
ther modified as already stated by washing and sorting in connec-
tion with the redeposition of the pebble.
Still another factor that is even more difficult to estimate is that
of secondary enrichment of the rock after it has reached its present
location. That the secondary enrichment of the pebble has been
more effective at some localities than at others is doubtless true.
even though the particular conditions that have brought about this
result may not be understood. This subject is discussed in a suc-
ceeding paragraph.
SINK HOLES.
Sink holes, although not numerous in the land pebble phosphate
beds, are occasionally met with in mining, one such having been
seen by the writer in the pit of the Pierce Phosphate Company at
Pierce. The break in this sink is through both the overburden and
the phosphate bed, as is shown not only by the fact that the phos-
phate bed drops abruptly, but by the presence of "slickensides"
formed as the clay moved downward into the sink.

STREAM BEDS.
In the same pit and near the sink, an old stream bed was cut
through in mining. In the bed of the stream is found fine, loose.
more or less well stratified sand, which is usually dark, although in
places it is gray or light colored. This stream had cut down to the
phosphate matrix, and at one point had almost cut out the coarse
or upper part of the deposit; in other words the stream had cut
almost entirely through the Bone Valley formation. Subsequently
owing to changed conditions the stream valley had been filled with
sand. It is quite possible that both the sink hole and the stream bed
were formed during the time of the Pleistocene elevation when the
land stood higher than at present.

CLAY BEDS BENEATH THE PEBBLE PHOSPHATE CONGLOMERATE.
In pit No. o1 of the Prairie Pebble Phosphate Company near
Mulberry, some 12 or 15 feet of clay matrix carrying but little phos-
phate was found to lie beneath the pebble conglomerate, the sump
hole of the pit being sunk into the clay. This clay matrix apparently
does, rt reep(fe jga 1h ed rock but bl b 4faITihthe Bone Valley
.. UNIVERSE OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


formation. The accumulation of this amount of clay with little
coarse pebble may be readily understood. Doubtless this particular
depression was so located that when the area was partially sub-
merged it did not receive the strong wash of either waves or stream
currents, but received only the clay or mud from the wash of the sur-
rounding lands. These conditions continued until some 12 or 15
feet of mud with little coarse material accumulated at this spot.
Afterwards, however, the conditions changed somewhat so that a
conglomerate of pebble accumulated of sufficient thickness to form
the workable beds of the pit. Similar conditions may be expected at
other localities.

SAND AND FINE PEBBLE BENEATH THE PEBBLE PHOSPHATE
CONGLOMERATE.
In one of the pits of the Pierce Phosphate Company that was
being worked some years ago, there were to be observed lying be-
neath the workable phosphate beds, one to three feet of quartz sand
intimately'mixed with black phosphate pebble. A deposit of this
kind lying near the bed rock is not uncommon, and by the miners
is called "pepper and salt." As in the case of the clay beds the
"pepper and salt" is evidently the result of local conditions. The
material in this particular case was fairly well sorted, the sand
grains and the minute phosphate pebble being of approximately the
same weight.
IRON ROCK IN THE OVERBURDEN

Occasionally the overburden, or several feet of it next beneath
the soil, becomes firmly cemented. Under these conditions the rock
may become very hard necessitating blasting. The cementing sub-
stance in most instances is iron oxide, carried into the sand by sur-
face water. This phase of the overburden was observed in the pit
of the Florida Mining Company near Mulberry, where the section
was as follows:
I, Incoherent sand and soil----------------------------------- 6 feet
2. Indurated sands, reddish in color and probably cemented with iron
oxide ------------------------ ------------------- Io feet
3. Phosphate bed ----------------------------------------- 15 feet
4. Yellow marl, "bed rock."


S:,O. :ricginal from
... UNIVERSITY OF MICHIGAN







68 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

INCOHERENT SURFACE SANDS AND SOIL.
The loose surface sands are believed to have been derived by
disintegration from the phosphatic sands beneath. Accordingly
they are found to be variable in thickness depending upon the local
conditions. As a rule an irregular line produced by decay separates
the loose sands from the more or less indurated sands beneath. At
places, however, the phosphatic sand passes gradually into the sur-
face sand and soil.
HARDPAN IN THE SUB-SOIL.
Hardpan which is frequently present in the sub-soil consists as
a rule of sand held together more or less firmly by either organic
matter or iron oxide acting as a cement. The hardpan is prevail-
ingly dark brown or chocolate colored and may be from two to
several feet in thickness.

VESICULAR AND CALCAREOUS SAND ROCK.
Occasionally the phosphatic sand rock of the overburden is found
to be vesicular and calcareous. This phase of the formation was ob-
served in the pit of the Dominion Phosphate Company, and in one
of the pits of the Medulla Phosphate Company.

OVERBURDEN ABSENT OR REDUCED IN THICKNESS.
It is not unusual to find the overburden locally much reduced in
thickness, and in some instances entirely absent. This is due evi-
dently to surface wash and erosion which has removed the sands
of the overburden, and in some instances has cut into the phosphate
beds. Elsewhere the overburden increases in thickness and finally
reaches a point beyond which the phosphate beds under present con-
ditions cannot be economically worked.

BOG IRON ORE IN THE OVERBURDEN
Local small deposits of bog ore are not uncommon. These
are found near the surface and as a rule mark the location of small
ponds. An unusual phase of iron rock lying practically at the sur-
face is that seen in pit No. 4 of the Phosphate Mining Company
one half mile northeast of Mulberry where the rock although hard,
contains many cavities.

S*: .. O. :ric final from
.. :.O *' UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


SECONDARY ENRICHMENT IN THE PHOSPHATE BED.
The manner of accumulation, structural details, and local varia-
tions of the land pebble phosphates having been described, there yet
remains for consideration the very important factor of secondary
enrichment within the bed itself. That secondary enrichment has
occurred in the phosphate bed is shown by the fact that the phos-
phate pebbles washed from the bed rock contain only from 42 to
58 per cent tri-calcium phosphate, while those washed from the
phosphate bed contain from 66 to 77 per cent tri-calcium phosphate.
In fact this tendency to phosphatization is general in the beds, and
with the exception of oyster shells and pieces of wood, which are
silicified, has affected the pebbles and rock fragments, the bones
and teeth of vertebrates, and the casts of the invertebrates.
The agency through which secondary enrichment has been ac-
complished in this formation is with little doubt the surface waters
which move downward through the phosphatic sands of the over-
burden, and laterally through the phosphate bed. A similar process
contributed as has been shown in a previous paper to the enrichment
of the hard rock phosphate.
Secondary enrichment of phosphate rock is doubtless due to the
fact long since demonstrated by Reese* that when waters holding
calcium phosphate in solution, come in contact with calcium car-
bonate, a reaction takes place by which the phosphate replaces the
carbonate. In view of this fact it seems not at all impossible that
the phosphate pebbles of. the bed rock itself may have their origin on
this process of enrichment, the original pebbles of sandy marl having
under favorable conditions become phosphatized possibly from phos-
phoric acid in solution in the sea water.

*Chas. L. Reese, Amer. Journ. Sci., 3rd Ser., Vol. 43, p. 402, 1892.










S ) L Origlinal from
..O :UNIVERSITY OF MICHIGAN







70 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.


Fig. 7.-Top view of a land tortoise found in pit No. 5 of the Phos-
phate Mining Company, Nichols, Fla. The front part of the carapace
is wanting having been destroyed at the time the specimen was imbedded. The
part of the carapace restored in the drawing is indicated by dotted lines. A part
of the plastron is also preserved. Fla. Geol. Surv. collection No. 5oo0. One-
twelfth natural size. Donated by the Phosphate Mining Company.


: Q ) L Orriginal from
.. UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


FOSSILS OF THE LAND PEBBLE PHOSPHATE DE-
POSITS.

It is not the writer's purpose to include in this paper a descrip-
tive or monographic treatment of the fossils of this formation. It
is necessary, however, in order to fully understand the beds, to
make mention of the common fossils and to account for the asso-
ciation of land and marine forms, as well as for the inclusion within
the beds of fossils of different geologic periods.
The fossils of the land pebble phosphate deposits include: (I)
Those that were derived from the underlying formations and hence
represent animals that lived at a time antedating the phosphate-
bearing formation; and (2), those that are contemporaneous with
the formation, having lived at the time when the phosphate beds
were being accumulated. It is sometimes assumed that the fossil
bones found in the phosphate beds are the source of the phosphoric
acid. This assumption obviously is entirely erroneous.

FOSSILS DERIVED FROM THE "BED ROCK."
The fossils from the "bed rock" in this formation include chiefly
teeth of sharks and rays, worn pieces of ribs, casts of invertebrates,
and silicified corals. Of these fossils the sharks' teeth and silicified
corals are highly resistant; the pieces of ribs also, have sufficient
endurance to withstand removal from one formation to another
The casts of the invertebrates although not particularly resistant will
nevertheless withstand fully as much attrition as the fragments of
the "bed rock" marl with which they are associated. Since these
fossils are found in the "bed rock" marl it is scarcely to be doubted
that some of them now found in the phosphate beds were derived
from that formation.

FOSSILS FROM MIOCENE STREAM AND RIVER DEPOSITS.
The geologic history of southern Florida leads to the belief that
the upper Oligocene marl. the "bed rock," was exposed as a land
surface during a part or all of the Miocene period. If this is true,
it is evident that residual material, stream and river deposits were
accumulated during that time in which doubtless the remains of
Miocene land animals were preserved. If so, it is apparent that
when the area was again submerged, the more resistant of the
Miocene f6ssils .may .h vet liitcluded alMfi p^al







72 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

materials in the pebble phosphate conglomerate. While this is rec-
ognized as a possible source of certain of the Miocene forms of the
land pebble phosphate conglomerate, the study of the fauna has not
progressed far enough to permit one to determine whether or not
any considerable number of the fossils were so derived.

FOSSILS CONTEMPORANEOUS WITH THE PHOSPHATE DEPOSITS.
The fossils representing animals contemporaneous with the phos-
phate deposits include both land and aquatic forms. The land ani-
mals in the beds no doubt represent forms that were washed in from
the nearby shore, or were carried in by streams, while the aquatic
forms are those that inhabited the shallow waters in which the beds
were accumulating.

LAND FOSSILS OF THE PHOSPHATE BED.
The land animals of the land pebble phosphate beds include
mastodons, rhinoceroses, horses and land turtles. The mastodons
found in this formation are not unlike the form described by Leidy
from near Archer as Mastodon (Trilophdon) floridanus. The parts
commonly found include teeth, vertebrae, broken ribs, and occasional
leg bones. Skulls are seldom preserved. The mastodon teeth
found in the deposits present considerable variation and it is prob-
able that more than one species is represented.
Rhinoceroses are found in this formation, two or more species
being present. According to Mr. James Gidley Teleoceras fossiger
has been definitely identified by him from a tooth obtained from this
formation near Mulberry.* On the other hand specimens represent-
ing parts of the jaws and teeth presented to the Survey by the
Amalmagated Phosphate Company are clearly distinct from T. fos-
siger.

*Statement before the Palaeontology Society, Dec., 1914.








Co)I Lc Original from
... : :! *UNIVERSITYOF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


The presence of rhinoceroses in the formation is believed to
establish definitely the fact that the beds cannot be later than early
Pliocene, since rhinoceroses in America apparently did not survive
beyond that time.
A few horse teeth have been obtained from the pebble phosphate
beds, all of which are referable to the genus Hipparion, horses of
the modern genus Equus not being present.
The tree trunks which are occasionally found silicified both in
the phosphate beds and the overburden no doubt floated in from
the nearby shore, or were carried in by streams. The cellular struc-
ture of the wood is not well preserved and the species has not been
identified.
Turtle remains are found not infrequently in the Bone Valley
formation. As a rule scarcely more than fragments or plates from
the carapace are found. The Phosphate Mining Company, how-
ever, fortunately recovered a considerable part of the carapace and
plastron of a very large land tortoise from their pit at Nichols. This
specimen has been presented to the State Geological Survey and is
preserved in the State Survey collection. An illustration of the
specimen is given on page 70.

MARINE AND ESTUARINE FOSSILS OF THE PHOSPHATE BEDS.
The marine fossils of the phosphate beds include several verte-
brate types and a few invertebrates. The aquatic vertebrates in the
formation include cetaceans, crocodilians, and fishes. The most
common cetaceans are long snouted forms belonging probably
in the family Platanistidae. Fragments of the skull and jaws,
and also the vertebrae are not uncommon. It seems probable also
that the broken ribs found in such abundance in the phosphate beds
pertain to these small cetaceans.
Crocodilian teeth, vertebrae and bones are not uncommon in
the phosphate beds, and the members of this order were no doubt
abundant in the shallow waters in which the land pebble phosphates
were accumulating. Among the best preserved of the specimens
that have been obtained is a part of the upper and lower jaw of a
gavial from the pit of the Amalgamated Phosphate Company, pre-
sented by the Company to the State Geological Survey. The species
being new, the writer has suggested for it the term Tomistoma
americana.* The discovery of these fossils in the Bone Valley for-
*A New Gavial from he(thkt i i tiary of Fl1 xt,
Aug., 1915.







74 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.


Fig. 8.-Tomistoma americana Sellards, a gavial found in the land pebble
phosphate deposits. Approximately one-third natural size. Fragment of the
lower jaw.

mation is of interest since it affords evidence of the existence of
gavials in North America as late as the Miocene or early Pliocene,
although they have since disappeared from the Western Hemisphere,
the modern gavials being found in Asia and Africa. That the spe-
cies found in the pebble phosphate beds is to be placed with the
gavials rather than with the crocodiles is indicated not only by the
long narrow snout, but also by the fact that the first mandibular
tooth bites on the outside and not in the inside of the upper jaw.
The fish remains in the phosphate bed include chiefly teeth of
sharks and rays. Sharks' teeth in particular are extremely abund-
ant. It is difficult, however, to determine whether the teeth are
from sharks that were living at the time the phosphate pebble ac-
cumulated, or represent teeth residual from the marl beneath. Since
the sharks' teeth are highly resistant they would readily withstand
the slight amount of erosion incident to their reaccumulation in the
phosphate beds without showing any appreciable attrition, and it
seems probable that most of these teeth have been washed in from
the "bed rock." The range of the species of sharks as identified by
their teeth is considerable, and it is doubtful if it can be definitely
determined whether the teeth in this formation are those of Oligo-
cene, Miocene or Pliocene sharks. Plates from the teeth of the
rays are also found both in the "bed rock" and in the phosphate
beds. It is very probable that the teeth of sharks and rays taken
from these beds represent a mixture of Oligocene and Pliocene
forms.
SOriginal from
... :!' UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


Phosphatized casts of invertebrates are rather numerous in the
phosphate beds. Most, if not all of these, however, are washed in,
as previously stated, from the bed rock beneath. Among the in-
vertebrates in the phosphate beds, which seem to be contemporaneous
with the deposits, are silicified oysters found in the pit of the Pem-
broke mine of the Coronet Phosphate Company, where they occur
in some abundance making up a well marked stratum within about
two feet of the top of the workable phosphate bed. Dr. W. H. Dall
of the U. S. National Museum who has kindly examined specimens
of this oyster writes that it is probably Ostrea mauriciensis Gabb,
differing from the ordinary 0. virginica by the deep pit under the
hinge line.* The two species, however, are very closely related.




I I
/ I



!i S I \






Fig. 9.-Side view of land tortoise. Same specimen as figure 7. One-twelfth
natural size. The part restored is indicated by dotted lines.

If this oyster is 0. :nauriciensis it would seem that it must have
been washed into this formation from the Alum Bluff formation.
However, from the fact that the oysters occur in abundance, and in
soine cases in large masses near the top of the workable phosphate
bed, it seems probable that they actually belong to the Bone Valley
formation. 0. mauriciensis, it may be noted (Dall, Bull. 90, p. 123,
U. S. Nat. Mus.) is itself a species of doubtful validity.
The fossils that have been obtained from the formation indicate
that the land pebble phosphate deposits were accumulated during

:- T f i nial from -
*Letter of, May c14j ,i. Ic -0 r t S I
UNIVERSITY OF MICHIGAN







76 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

THE RIVER PEBBLE PHOSPHATE DEPOSITS.

The river pebble phosphates are found in Florida in varying
amounts wherever streams have cut their channels into the phos-
phatic marls either of the Alum Bluff or of the Jacksonville forma-
tion, or across the phosphate conglomerate of the Bone Valley for-
mation. The pebbles may be found in recent bars in the streams, or
in the bars of an earlier channel or valley. The age of the deposits,
therefore, on any one stream, may range from Pleistocene or earlier
to recent. The immediate origin of these local, river deposits is
obviously the formation across which the stream flows. In grade
the river pebble deposits seldom exceed 66% tri-calcium phosphate.

FOSSILS FROM THE RIVER PEBBLE PHOSPHATE DEPOSITS.
The vertebrate fauna of the river pebble phosphate deposits of
Florida includes elephants, mastodons, horses of the genus Equus,
bison, deer, tapir, manatee, sloths, glyptodonts, and armadillos.
With this assemblage of clearly Pleistocene forms is associated in
some localities probably by accident the Pliocene horse'Hipparion.
The deposits contain also cetaceans, turtles, crocodiles and fishes.
Elephants were present in Florida during the Pleistocene and
possibly during a part of the late Pliocene, their remains being
found at many localities throughout the State in the river pebble
phosphate deposits and elsewhere. The Florida elephant has usually
been identified as Elephas columbi Falconer. It would seem, how-
ever. that the enamel folds or plates in the teeth are coarser and far-
ther apart than are those of E. columbi. According to Lucas*
the number of cross folds in the teeth of E. columbi average eighteen
in a space of ten inches, while in the teeth of the Imperial elephant
the cross folds average twelve in the same space. The number of
cross folds or plates in the elephant teeth that have been obtained by
the writer from Florida will seldom exceed twelve to fourteen in a
space of ten inches.
The mastodon commonly found in the river pebble phosphate
deposits is that known as the American mastodon, Mammut ameri-
canum, a species that extended during Pleistocene time over a con-
siderable part of North America. This mastodon is distinguished
from those found in the land pebble phosphate deposits by the fact

1M-Gql S(rv TVjlpien Pliocene and MT4t~iiSg, 1906.
M ..... P UNIVERSITY OF MICHIGAN






PEBBLE PHOSPHATE DEPOSITS. 77

that the valleys across the teeth as seen on the unworn grinders,
are open, not being blocked by buttresses from the conules. The
tusks likewise lack the band of enamel which characterizes the ear-
lier mastodons. Associated with the American mastodon in the river
pebble phosphate deposits may be found occasionally teeth of the
earlier forms washed in from the older formations. This associa-
tion is found, however, only in streams that cut across the Pliocene
cr Miocene formations.
Horses of the genus Equus were present in Florida during Pleis-
tocene and possibly also during the late Pliocene, their remains be-
ing found in numbers in the river pebble phosphate deposits and
elsewhere throughout the State. The parts preserved include for
the most part the teeth and occasional bones. Several species of
Pleistocene horses have been described from Florida as follows:
Equus caballas, E. Icidyi and E. littoralis. Associated with the
horses of this modern genus is found in the river pebble deposits
horses of the extinct genus Hipparion. As in the case of the masto-
don this association is noted only in the bed of streams that cut into
Pliocene formations.
The bison obtained from the river pebble phosphate deposits rep-
resents an extinct species, probably Bison latifrons. The deer, tapir
and manatee, however, are scarcely distinguishable from the living
species.
The sloths, now confined to South America, extended in Plei-
stocene time over a considerable part of the United States, their re-
mains being found at different localities throughout the State in
the river pebble phosphate deposits and elsewhere. Glyptodonts,
a division of the Edentates now extinct, likewise extended their
range into North America during Pleistocene time. They are
found in Florida in the river pebble phosphate deposits and at some
other localities.
Armadillos, or armadillo-like animals, are represented in the
Florida Pleistocene by the genus Chlamytherium, which in some
respects is intermediate between the Glyptodonts and the Arma-
dillos. Parts of the skeleton or plates from the carapace of a species
of this genus have been obtained from Peace Creek, White Beach,
Hillsboro River, and Vero. Distinctive characters of the genus.are
found in the molar teeth which are elongated from front to back,
the larger teeth being two or three times as long as broad. On the
exterior of the tooth is a broal deep furrow which partially divides
': .'! *UNIVERSITYOF MICHIGAN







78 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

the crown into an anterior and posterior pillar. On the inner sur-
face of the tooth is seen two or three faint furrows, which, however,
scarcely appear on the crown. The cross section of the molar is
thus that of an ellipse slightly compressed at the center more strongly
so from the outer side.
The lower jaw is more or less pointed in front and contains
nine teeth. Of the teeth the posterior six are molariform in appear-
ance and function, while the anterior three are reduced and are more
nearly circular in across section. In general appearance the jaw
is distinctly glyptodont. From the glyptodonts, however, the genus
is distinguished not only by the structure of the teeth which lack
the tripartite division of the crown and base, but by the fact that the
ramus of the jaw is inclined gently backward, and does not turn up
at a right angle, or more than a right angle as in the glyptodonts.
Moreover, the shield consists of an anterior and posterior buckler
with several movable transverse bands between similar to those of
the armadillos. Although referred to the Dasypoda, the genus is
recognized as in many ways intermediate between the armadillos
and the glyptodonts.*

LOCAL DEPOSITS OF RIVER PEBBLE PHOSPHATE.
The localities in the State where small deposits of river pebble
phosphates have accumulated are rather too numerous to describe
separately. A number of the important localities, however, may
be referred to. For the location of the deposits see the map on
page 30.
S PEACE CREEK.
Peace Creek originating in the northern part of Polk County.
flows south across both the Alum Bluff phosphatic marl and the
land pebble phosphate deposits. The conditions for the accumula-
tidn of pebble phosphate in the valley of this stream, therefore, have
been particularly favorable, and it is on this stream that the most
extensive river pebble phosphates in Florida have been found. The
Peace Creek beds have also a historic interest since it was here in
1888 that phosphate mining in Florida began.
Owing doubtless to the mixed condition of the fossils, some dif-
ference of opinion has been expressed as to the age of the Peace

*Sellards. E. H., Chlamytherium septentiionals, an Edentate from the
Pleistocene of Flofdi.(# &.ourn. Sc. Vol. xq)rI lif~g :
-2 -: UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


Creek beds. From his examination of these beds in 1891 Dr. W. H.
Dall was led to believe that, on the evidence of stratigraphy and
invertebrate Palaeontology, the beds were to be referred to a mid-
Pliocene stage.* The account given by Dall, however, does not
appeal to the writer as being conclusive on this point. At the
mouth of Mare Creek, six miles above Arcadia, Dall observed a
marl, designated by him as the Arcadia marl, from which, however,
no characteristic fossils were obtained. Lying upon this marl was
observed a calcareous and phosphatic sand rock, which was identi-
fied from the marine shells that it contained as lower Pliocene.
With this phosphatized rock is associated a bone bed. Dall states
(1. c., p. 132) "The mammalian bones at this point appear to lie
on this stratum, and where it is broken up, as is most commonly
the case, are mingled with its fragments and blackened in the same
way." Three miles down stream at Singleton's Landing an oyster
bar was observed which proved from its invertebrate fauna to be
late Pliocene. Moreover, near Zolfo Springs, this marl was ob-
served to overlie the "phosphate stratum." From these exposures
Dall .was led to believe that the Peace Creek bone bed lay between
the lower Pliocene phosphatic sand rock and the upper Pliocene shell
marl.
It is to be nbted, however, that the bone bed is found on top of
the phosphatic sand rock, and that there is no evidence that the
bone bed is present beneath the upper Pliocene shell marl. It is
true that the upper Pliocene is reported to overlie the phosphatic
stratum at Zblfo Springs. It is not shown, however, that the bone
bed is present between the upper Pliocene and the phosphatic sand
rock.
It is apparent that both Pliocene and Pleistocene deposits lie
along Peace River, and have been and are being reworked and re-
accumulated by stream action. It necessarily follows, therefore,
that the fossils of these formations, or such of them as are sufficiently
resistant to withstand slight erosion, are intimately mixed in the de-
posits along the river. Moreover, since Peace River cuts into the
Alum Bluff marl it is to be expected that some of the resistant fos-
sils from that formation, particularly sharks' teeth, have persisted
in the river pebble deposits. It is hardly necessary to add that only

*U. S. Geol. Surv. Bull. 84, pp. 130-I33, 1892.

)' Ori jirl al from
... :.OO *UNIVERSITY OF MICHIGAN







80 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

under very exceptional circumstances can a formation be older than
the latest of the fossils that it contains.
The following section is found on the east bank of Peace River
about three hundred yards up stream from the Brownsville Bridge,
and one-half to three-quarters mile above the Mare Creek section.
I. Soil and incoherent gray sand ------------------------------- 4 feet
2. Yellow sand, somewhat indurated ---------------------------- 5 feet
3. Fine black phosphate pebble, interbedded with sand, and containing
also leaves, branches and partly decayed logs to water's edge -- 3 feet

This exposure is clearly a river deposit, and can hardly be older
than Pleistocene. From this exposure in addition to the decayed
wood and leaves was taken the usual Peace Creek fossils including
teeth of the elephant, E. columbi, tooth of the deer, Odocoileus,
broken ribs and teeth of sharks and rays.

1 2



---~---















Fig. Io.-Chlamytherium humboldtii, left jaw, interior view. A tracing
taken from Lund's original illustration. One-half natural size. Introduced for
comparison with specimens found in Florida. (2) Chlamytherium septentrionalis.
Two teeth from the right lower jaw. At the left, the third tooth from the
back of the jaw (presumably the seventh from the front); the grinding surface
of the tooth measures 22 by 6 mm. At the center, the fourth tooth from the
back, (presumably the sixth from the front); the grinding surface of the tooth
measures 23 by 6 mm. At the right, median section through the fourth tooth
from the back of the jaw, showing by diagrammatic section the cavity at the
base of the tooth. All from specimen No. 1722, Fla. Geol. Surv. Natural size.
From Vero, Fla. Oriiginral from
l Q 0 UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


The fossil vertebrates identified by Dr. Leidy from the river
pebble phosphates on Peace Creek, include the following:* Tapirus
terrestris (T. americanus); Equus sp.; Hipparion (Hippotherium)
ingenuum; Hipparion plicatile; an upper molar tooth compared with
Bison americanus; Antler bones and teeth of deer not differing from
those of Odocoileus (Cervus) virginianus; Elephas columbi; Chla-
mytherium septentrionalis (Chlamydotherium humboldtii); dermal
plates resembling those of Hoplophorus euphractus; Glyptodon peta-
liferous; Megalonyx jeffersonii; Manatus antiques; several ceta-
ceans; Emys cuglypha; one or two species of Trionyx; Testudo
crassiscutata; two vertebrae of a large serpent; dermal plates of a
crocodile; Ephippus gigas; dermal turbercles of ray; and teeth of
Diodon, Myloiobates, Oxyrhina, and Galeocerdo.
Of the species of this list several evidently represent fossils
washed in from the Alum Bluff and Bone Valley formations through
or into which the stream has cut its channel. This applies to some
at least of the fish teeth. The Hipparion remains in these beds are
probably also derived from the older formations. The teeth of
this horse are quite resistant to erosion and although rather numer-
ous in the Peace Creek beds it is probable that they have been car-
ried into the deposits either from the reworking of Pliocene stream
deposits immediately along the river or from the land pebble phos-
phate deposits, across which the stream flows and in which Hippa-
rions are found. This view is supported by the fact that the teeth
of Hipparion are found in the deposits in all stages of erosion, in
many instances reduced to a mere fragment of their former size.
Moreover, Hipparion in association with the Pleistocene fauna is ob-
tained in Florida only from those streams that cut across Pliocene
beds. At some other localities, notably at Vero in St. Lucie County,
the Peace Creek Pleistocene vertebrate fauna is found in a stream
that flowed across early Pleistocene shell marl deposits. From this
locality no Hipparion remains have been obtained.

ALAFIA RIVER.
Pebble phosphates similar to those in Peace Creek, are found
and have been worked to some extent on the Alafia River. This
stream originates in the land pebble phosphate area of Polk County

*Description of Vertebrate Remains from Peace Creek, Florida. Wag.
Free Inst. Sci. Trans. Vo :j, o. I889. Original from
0- UNIVERSITY OF MICHIGAN







82 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

and flows west to Tampa Bay. It therefore cuts across the land peb-
ble phosphates and in the lower part of its course cuts into the Alum
Bluff marl, from both of which formations the river pebble is de-
rived.
MANATEE RIVER.
A limited amount of pebble phosphate is found along Manatee
River and its tributaries derived largely from the Alum Bluff marl
into which the river has cut its channel.

NORTH CREEK.
North Creek in Manatee County affords an interesting illustra-
tion of the accumulation of pebble phosphate in successive forma-
tions. This stream cuts into the Alum Bluff marl which at this lo-
cality contains a considerable amount of phosphate pebbles. Rest-
ing directly upon the marl is found a Pleistocene shell marl, which
is likewise phosphatic, the pebble having been derived from the
Oligocene marl beneath. Finally in the recent bars of the stream is
found a mixture of shell, pebble phosphate and sand.

CALOOSAHATCHEE RIVER.
Dark colored phosphate pebbles similar to that on Peace Creek
are found in the bed of Orange and Caloosahatchee Rivers in
Lee County. That found along Orange River is derived from a
yellow phosphatic marl which rises two or three feet above water
level. The marl exposed here contains an abundance of large
oysters, pectens and other invertebrates. The pebble phosphate of
the Caloosahatchee river is probably derived from the same phos-
phatic marl. If so, however, it lies beneath the typical Caloosa-
hatchee marl and is nowhere exposed above water level. The Ca-
loosahatchee marl, itself, contains occasional phosphate pebble and
phosphatized casts of shells, but probably not in sufficient abundance
to account for the accumulation of the phosphate in the bed of the
river, particularly in the lower course of the stream. The phosphate
pebble found in this river and its tributaries is doubtless derived
either directly or indirectly from the Alum Bluff formation which
although not exposed, probably lies at no great depth below the sur-
face.


S: v , Original from
... : *UNIVERSITY OF MICHIGAN







PEBBLE PHOSPHATE DEPOSITS.


BLACK CREEK.
The pebble phosphates on Black Creek in Clay County are de-
rived from the phosphatic marls through which the stream has cut
its channels. This marl, as previously stated, has been referred, on
the basis of the invertebrate fossils, to the Jacksonville formation.

OLUSTEE CREEK.
Pebble phosphate is found on some of the tributaries of Olustee
Creek in Bradford and Columbia counties, and probably in the
creek itself. The pebble is derived from phosphatic marls which
probably represent the Alum Bluff formation.

ALLAPAHA RIVER.
A limited amount of pebble phosphate is found on the Allapaha
River near Jennings in Hamilton County. This pebble is derived
without doubt from the Alum Bluff formation.

SOPCHOPPY RIVER.
Pebble phosphate has been found to some extent in the valley of
Sopchoppy River and some other streams in Wakulla County, the
pebble being derived from the Alum Bluff formation. The local
beds of phosphate in Wakulla County were among the first reported
in Florida, having been described by Dr. J. Kost in his report to
Governor Perry in 1887.















Fig. i .-Ostrea from the Pembroke mine of the Coronet Phosphate Com-
pany. Silicified oysters ate-found at this locality in cgj4j#f4rbaundance
within about it'ft f. t O' workable ft t F( I"i(Y ey1
formation).







84 FLORIDA GEOLOGICAL SURVEY-SEVENTH ANNUAL REPORT.

RELATION BETWEEN THE HARD ROCK AND THE
LAND PEBBLE PHOSPHATES.
It may be of interest in this connection to note some points of
similarity as well as of contrast between the hard rock and the land
pebble phosphates of Florida. First of all both the hard rock and
the land pebble deposits are contemporaneous in time and are de-
rived from the same source, namely, the phosphatic marls of the
Alum Bluff formation. However, in the accumulation of the hard
rock phosphate chemical action has predominated, resulting in the
formation of boulders of very high grade. The land pebble phos-
phates on the other hand represent primarily a mechanically accumu-
lated pebble conglomerate, although as in the case of the hard rock,
the grade has been subsequently improved by secondary enrichment.
The relation of the deposits to the underlying formations is like-
wise different. The hard rock phosphates rest upon the Ocala lime-
stone, the upper Oligocene formations having entirely disintegrated.
The pebble phosphate deposits on the other hand rest upon the
eroded top surface of the Alum Bluff (upper Oligocene) formation.
Land animals are present in some abundance in both formations.
but it is only in the land pebble phosphate deposits that such dis-
tinctly aquatic forms as cetaceans have as yet been found.*

*The Zeuglodont taken from the hard rock phosphate deposits referred to
on an earlier page is residual from the Ocala formation.

















O. 'ricginal from
UNIVERSITY OF MICHIGAN








ILLUSTRATIONS.
To Accompany Paper On
THE PEBBLE PHOSPHATES OF FLORIDA.
Figures 12-52.


Fig. 12.-A part of the grinding surface of the tooth of the elephant, prob-
ably Elephas columbi var. Natural size. Fla. Geol. Surv. collection, No. 2234.
Dredged from the Withlacoochee River. Width of tooth 8 cm. About five plates
per 0oo mm. The Florida elephant differs from the typical E. columbi in that the
plates are much coarser tha -Tnhat. is. This elephan O&ilfa'ia ritrnPleisto
cene deposits. c UNIVERSITY OF MICHIGAN













VIEW SHOWING EXPOSURE OF THE ALUM BLUFF
FORMATION.









Fig. 13.-Alum Bluff on the Apalachicola River. Made from a photograph
taken by Dr. E. A. Smith, Oct. 29, 1890. This bluff, at the base of which is found
the type exposure of the Alum Bluff formation, is about 166 feet high.





The Alum Bluff formation is extensive in Florida and is exposed
at many localities from the Apalachicola River to Sarasota Bay.
This formation, which is more or less phosphatic throughout, is of
special interest in connection with the phosphate deposits since from
it directly or indirectly has been derived the workable phosphate beds
of Florida.


Q ,0~vrj


Original from
UNIVERSITY OF MICHIGAN

































































I.


Oric inal from
UNIVERSITY OF MICHIGAN


<<.


Al


V,"-


Co o lc
87


4 __ ^


c,,
~d'T;:? ri r










VIEWS SHOWING METHODS OF MINING
PHOSPHATE IN FLORIDA.


PEBBLE


Fig. 14.-View in the pit of the Pembroke mine of the Coronet Phosphate
Company, showing in the back ground, removal of overburden by steam shovels.
In the foreground may be seen one of the hydraulic guns used in mining the
land pebble phosphate. The phosphate rock, together with the matrix, is washed
into sump holes and is then pumped through pipe lines to the washer plant.


Fig. 15.-A near view in the same pit. Mining phosphate rock by the hy-
draulic method. This method is used in many of the mines in removing the
overburden as well as in mining the rock.


Fig. 16.-Phosphate washer.
phate Company.



















E l


View taken at the plant of the Dominion Phos-



















Oriqinal from
UNIVERSITY OF MICHIGAN

















-'a











VIEWS SHOWING THE LAND PEBBLE PHOSPHATE DE-
POSITS, AND THEIR RELATION TO THE BED
ROCK MARL.












Fig. 17.-View in pit of the Palmetto Phosphate Company near Tiger Bay,
showing an inclusion near the base of the phosphate bed (Bone Valley forma-
tion) of a large mass of the bed rock marl (Alum Bluff formation). (i) Sur-
face soil and loose sand. (2) More or less indurated sands of the overburden.
(3) Workable phosphate bed. (4) Inclusion of the Alum Bluff phosphatic marl
within the phosphate bed. (5) Bed rock marl.


Fig. 18.-View in the pit of the Pierce Phosphate Company showing the un-
conformity between the phosphate bed (Bone Valley formation) and the bed
rock marl (Alum Bluff formation). (i) Workable phosphate bed. (2) Bed
rock marl.


Fig. 19.-General view of the pit and plant of the Pierce Phosphate Com-
pany, Pierce, Florida


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UNIVERSITY OF MICHIGAN
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VIEWS SHOWING CHARACTERISTICS OF THE LAND
PEBBLE PHOSPHATE DEPOSITS AND OF THE
PHOSPHATIC MARLS WHICH LIE BENEATH.






Fig. 20.-Phosphatic marl. The sample here illustrated was taken from
Black Creek. A similar marl, however, lies beneath the land pebble phosphate
deposits and is known as the "bed rock."
The analysis of the phosphate pebbles washed from this sample is as follows:
Moisture ---------------------------------------- .88
Insoluble matter, sand, etc. ------------------- ------------ 18.94
Phosphoric acid, 24.45, equivalent to tricalcium phosphate ------ 53.40
Iron and alumina -------------------------------------- 0.23
Calcium oxide, 5.07, equivalent to calcium carbonate ----------- 1.53


Fig. 21.-Sample from the land pebble phosphate bed showing light colored
phosphate pebbles imbedded in the matrix. From the pit of the Prairie Pebble
Phosphate Company near Mulberry.
The following is an analysis of this sample of matrix:
Moisture -------------------------------------------- .78
Insoluble matter, sand, etc. ------------------------------- 25.18
Phosphoric acid, 26.73, equivalent to tricalcium phosphate ------- 58.38
Iron and alumina ----------------------------------- 7.5
Calcium oxide, 1.02, equivalent to calcium carbonate ------------ 2.32

The following is an analysis of phosphate pebbles washed from this matrix:
Moisture ---------------------------------------- 1.33
Insoluble matter, sand, etc. -------------------------------- 6.87
Phosphoric acid 35.34, equivalent to tricalcium phosphate ------- 77.18
Iron and alumina --------------------------------------- 0.93
Calcium oxide, 1.39, equivalent to calcium carbonate ----------- 3.16














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VIEWS SHOWING CHARACTERISTICS OF THE PHOS-
PHATE PEBBLES OF THE BED ROCK MARL AND
OF THE PHOSPHATE BED.











Fig. 22.-Phosphate pebbles, shark and ray teeth washed from the bed rock
from the pit of the Phosphate Mining Company near Mulberry.


The analysis of these pebbles is as follows:
Moisture------------------ -------------------------
Insoluble matter, sand, etc.-- ------------------------
Phosphoric acid, 24.88, equivalent to tricalcium phosphate ------
Iron and alumina-------------- ----------------------
Calcium oxide, 7.58, equivalent to calcium carbonate ------------


.94
6.Ix
54.34
0.27
17.24


Fig. 23.-Phosphate pebbles from the phosphate bed (Bone Valley forma-
tion). From the pit of the Phosphate Mining Company, Mulberry.
The analysis of these pebbles is as follows:


Moisture-------------------- -----------------------
Insoluble matter, sand, etc.-- ------------------------
Phosphoric acid, 34.73, equivalent to tricalcium phosphate -----
Iron and alumina-------------- ----------------------
Calcium oxide, 3.73, equivalent to calcium carbonate ----------


3.22
.35
75.85
0.28
8.49


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94 UNIVERSITY OF MICHIGAN