Annual report of the Florida State Geological Survey

UNIVERSITY
OF FLORIDA
LIBRARIES

Florida Geological Survey Sixteenth Annual Report-Frontispiece

Pit of Florida Lime Company, Ocala, Florida. Type exposure of the Ocala Limestone.

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FLORIDA STATE GEOLOGICAL SURVEY

Hi-RMAN GUNTER, State Geologist

SIXTEENTH ANNUAL REPORT

1923-1924

ADMINISTRATIVE REPORT
MINERAL INDUSTRIES
LIMESTONE AND MARLS OF FLORIDA

Published for
THE STATE GEOLOGICAL SURVEY
Tallahassee, 1925

LETTER OF TRANSMITTAL

To His Excellency, Hon. Cary A. Hardee, Governor of Florida:

SIR :-In accordance with the law establishing the Survey, I have
the honor to submit herewith the Sixteenth Annual Report of the State
Geologist. The work of the Survey has progressed satisfactorily during
the year closing June 30, 1924. This report contains a statement of
expenditures from July 1, 1923, to June 30, 1924; a paper on the mineral
industries for the year 1923, and a report on the limestones and marls
of the State.
The present report is devoted principally to an economic considera-
tion of a most common mineral resource, namely, limestone and also of
marl. The limestone industry has grown very rapidly in Florida during
the last few years since it is so largely used as a road material. Other
uses are as a building stone, in foundation work, railroad ballast, agri-
culture and in the manufacture of lime. There is another very prom-
ising field for its use in this State-that of the cement industry. Alto-
gether it is thought the report is very timely and will be found of value.
The courteous consideration you have always shown those problems
with which this Department has to do is very much appreciated.
Very respectfully,

HERMAN GUNTER,
December, 1924. State Geologist.

TABLE OF CONTENTS.
PACE

A dm inistrative R report ........................................ ............ 7
Introduction .......... ............................................. 7
Recommendations .......... ......................................... 9
Expenditures of the Survey................. .......................... 12

Statistics on Mineral Production in Florida During 1923, by Herman Gunter.
(O ne M ap ) .......................................................... 17

A Preliminary Report on The Limestones and Marls of Florida, by Stuart
M ossom. (Figures 2 to 52- one M ap) .................... ............. 27

ADMINISTRATIVE REPORT

HER\MAN GUNTER, State Geologist

INTRODUCTION

Establishment.-The present Geological Survey was created by an
Act of the 1907 Legislature. Provision was made for the appointment
of a State Geologist and his duties were specified. The objects of the
Survey were also outlined and a continuing appropriation of $7,500 a
year was made for its maintenance.

Present Appropriation.-The law establishing the Survey has in no
wise been changed until the Legislature of 1923 appropriated for the
maintenance of this Department the sum of $10,345 for the fiscal year
ending June 30, 1924, and a like amount for the year ending June 30,
1925. This was apportioned as follows:
Salary of State G eologist............................... $ 3,000
Salary of Assistant Geologist........................... 2,000
Temporary Assistant ................................. 500
Stenographer .......................................... 1,320
Traveling expense and Field Equipment................. 1,500
Printing, Stationery and Engraving ...................... 1,500
P stage ............................................... 125
Incidental ............................................. 400
$10,345

This is an increase of nearly 14 per cent in the amount appropriated
annually for the support of the Survey in previous years. As a result
it has been possible to more actively prosecute field work and to print
an increased number of the annual reports. Although with this slightly
increased amount it has been possible to undertake some of the more
urgent field work and to have printed a larger edition of annual reports,
experience is proving that the support is far from adequate. Florida is
a large State and is developing at a very gratifying rate, all of which
means that there are more demands made upon the Survey now than
in former years. The Department is bending every effort to supply the
information relative to the natural resources of Florida, but it finds itself
at a serious disadvantage in many instances. A measure of the value

8 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

of a public institution is service. To render efficient and satisfactory
service a department must have tools with which to work, which in turn
means funds for investigations and for getting these results before the
public.
Publications of the Survey.-The present report constitutes the six-
teenth in the series of annual reports issued by the Survey. In addition
two bulletins and twelve press bulletins have been published. These have
been distributed to all sections of our own State and Country as well as
to some foreign countries. Many of them are now out of print, which
indicates the demand for reports having to do with the State's resources.
Distribution of Reports.-The Survey maintains an exchange list to
which all its reports are regularly sent. In addition an active mailing
list is made up from those persons returning the card notices which are
sent out as each new report is ready for distribution. These publications
are not sent broadcast but only to those who return the card notice indi-
cating their desire for the whole report or any one of the separate papers
composing it. The annual reports, in addition to the administrative and
statistical sections, deal with subjects pertaining to the State's varied
natural resources. They might, therefore, and often are, made up of
several separate papers, each devoted to some special subject. For this
reason the issuing of the report as a whole volume and also having a
certain part of the edition issued in the form of the separate papers of
which it is composed has proven an economical practice. This obviates
the necessity of sending the entire report to those who might only be
interested in one or more of the separate papers. Reports are sent free
to the citizens of Florida and upon payment of postage to all others.
Purpose of the Geological Survey.-The law creating the Florida
Geological Survey specifies some of the purposes for which such a depart-
ment was organized. Among these was to make known data pertaining
to "the minerals, water supply and other natural resources of the State,"
as well as the "occurrence and location of mineral and other deposits of
value, surface and subterranean water supply and power and mineral
waters, and the best and most economical methods of development."
The reports of the Survey shall also include "analysis of soils, minerals
and mineral waters, with maps, charts and drawings of the same."
In this connection it is appropriate to call attention to the fact that
the Geological Survey is the only State Department charged with the

ADMINISTRATIVE REPORT

distribution of information relatingto the natural resources just specified.
To such extent therefore this Department is the State's clearing-house
for making information of this character known. It may be said that
the Survey's function is both an educational and an economic one. The
collection of mineral and fossil specimens and their exhibition in the
Survey's Museum, duplicate sets of which shall be deposited in each of
the State Colleges, suggests the very apparent educational value.
Through an understanding of the geology of the State and its bearing
upon the occurrence of mineral and related deposits, the Survey is ex-
pected to contribute to and assist in an intelligent development of the
State's natural resources. That the Survey has endeavored to be of
service the subjects of the reports thus far published stand as evidence.
Furthermore, that the work has been effective is shown by the demand
for publications from the Department, many of them now no longer
available, and also by the number of letter requests and visits to the
office and Museum.
Specimens Submitted for Examination.-The matter of classifying
and reporting upon samples of rocks, minerals and fossils found in
Florida is one of the functions of the Geological Survey. Citizens
are urged to send in specimens of interest which they believe might prove
of value and thereby take advantage of this service which has proven
useful to many already. This applies not only to mineral specimens but
also to fossils. It is perhaps well to call attention to the fact that with
the large amount of excavation work in drainage, in mining and in
large construction of various kinds, there are being brought to light many
remains of vertebrate animals that were present in prehistoric times.
That many of these are lost is evident, but in many instances such remains
have excited the curiosity of the finders and have been preserved by
them. It is to be hoped that whenever fossils are found, both large and
small, they will be cared for and notification of such finds sent to the
State Geologist or the specimens themselves sent in for identification.

RECOMMENDATIONS
Museum.-In previous reports attention has been called to the fact
that Florida should provide for an adequate museum in which to prop-
erly exhibit the varied resources. The law creating the Geological De-
partment makes it the duty of the State Geologist to collect, determine
and label specimens illustrating the mineral and geological features of

10 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

the State and collections have been made since the Survey was organized.
A display of representative mineral specimens and also of many fossils
is made in the one room now available and allotted mainly for such
purpose. The space, however, is entirely inadequate and a large amount
of material suitable for display necessarily remains packed up as col-
lected. It is important that provision be made for the proper preserva-
tion and exhibition of material already on hand as well as to care for
future accessions and to stimulate interest in collecting and saving the
many fossil specimens that are unearthed from time to time.

Clay Testing Laboratory.-A preliminary report upon the clays of
Florida has been made and this has proven of very great interest. The
clay tests contained in this report were made in the laboratory of the
Ceramic Department of Cornell University. That the report has assisted
in directing attention to the possibilities of the Florida clays is evident
from the number of requests made for it and also in the interest shown
in examining the test bricklets on display in the museum. Furthermore,
there is a continued demand on the part of the citizens for additional
clay tests and in order to meet this the State should have a laboratory
for testing clays for brick-making and other purposes. In determining
the adaptability of a clay its physical as well as its chemical properties
should be known. In order to properly test a clay it is therefore neces-
sary to have testing equipment or machinery. A small but well-equipped
laboratory could be installed at an expense approximating $1500.

COOPERATION WITH THE UNITED STATES GEOLOGICAL SURVEY AND THE
UNITED STATES BUREAU OF SOILS

Cooperation is carried on between the U. S. Geological Survey and
the State Survey in the matter of the collection of statistics on the min-
eral production. This is very satisfactory; not only is it a saving in
expense but it assures uniformity of reports on the mineral output of
the State. It is urgently recommended that cooperation with the U. S.
Geological Survey to a greater extent be made possible. There should
be an annual fund available for this purpose. Such subjects as topog-
raphic mapping, the gaging of streams in order that data might be
available for prospective power development as well as to get data rela-
tive to flood control, the matter of the quality of our underground waters,
and other subjects, could be arranged for report on a cooperative basis.

ADMINISTRATIVE REPORT 11

The U. S. Geological Survey will meet the State Survey in work of this
nature upon a basis of an equal expenditure of funds.
There is an urgent demand for soil work in Florida. The U. S.
Bureau of Soils will cooperate with a State organization in mapping
soils. The Florida Survey has in former years cooperated with the
Bureau of Soils, but such work, owing to limited funds on the part of
the State Survey, had to be discontinued. With the continued rapid
development that Florida is making there comes a more insistent demand
for information regarding the soils of the different sections. It is rec-
ommended that a fund of $5,000 annually be made available for coopera-
tion with the U. S. Bureau of Soils. Such an appropriation may be
made contingent upon cooperation with the national bureau and would
thus result in the annual expenditure of $10,000 in the State for this
purpose.

12 FLORIDA GEOLOGICAL SURVEY--16TH ANNUAL REPORT

EXPENDITURES OF THE GEOLOGICAL SURVEY FROM
JULY 1, 1923, TO JUNE 30, 1924

The following itemized list shows the expenditures of the Survey
from July 1, 1923, to June 30, 1924. The total annual appropriation
during this period was $10,345. All bills and itemized expense accounts
are on file in the office of the Comptroller, duplicate copies being retained
in the office of the State Geologist.

LIST OF WARRANTS ISSUED FROM JULY 1, 1923, TO JUNE 30, 1924
JULY, 1923.
Herman Gunter, State Geologist, salary..................... $ 250.00
Herman Gunter, State Geologist, expenses ................... 44.90
R. M. Harper, Assistant, salary, part of July ................ 37.64
Florence M. Epperson, Stenographer, salary ................. 110.00
Sam E. Cobb, Jr., services.................................. 65.00
D. A. Dixon Co., mimeograph .............................. 65.00
Southern Telephone & Construction Co...................... 3.25
American Railway Express Co............................. 1.15
John W iley & Sons, Inc., Books............................. 6.50
Eastman Kodak Co., Flourescein............. ............. 10.00
L. B. M marshall, tabulation................... .............. 5.69

AUGUST, 1923.
Herman Gunter, State Geologist, salary .....................$ 250.00
R. M Harper, Assistant, salary............................ 166.66
R. M Harper, Assistant, expenses.......................... 57.28
Florence M. Epperson, Stenographer, salary ................. 110.00
Sam E. Cobb, Jr., services.................................. 65.00
S. E. Gray, work on shelving.................. ............ 16.05
Pichard Bros., shelving material ........................... 26.45
Leon Electric Co., supplies................................. 3.85
H H Bohler, sign on doors................................ 5.40
Yaeger-Rhodes Hardware Co., supplies ..................... 3.80
Southern Telephone & Construction Co.................. .... .. 3.25
Tallahassee Furniture Co., book cases...................... 147.00
M iddle Florida Ice Co.................................... 3.40
D. A. Dixon Co., supplies ............................ . . 4.10
Charles W illiam s, supplies................................. 11.15

SEPTEMBER, 1923.
Herman Gunter, State Geologist, salary ....................$ 250.00
Herman Gunter, State Geologist, expenses, August and Sept... 130.52
R. M. Harper, Assistant, salary, part of September ........... 38.89
Florence M. Epperson, Stenographer, salary................. 110.00
Sam E. Cobb, Jr., services, part of September ............... 13.00
Southern Telephone & Construction Co...................... 3.25
American Railway Express Co............................. 2.90
D. A. Dixon Co., supplies............. ..... ............ ... 16.95
Seaboard Air Line Railway, transportation .................. 110.15
M iddle Florida Ice Co..................................... 2.40
Florida State Historical Society.............. .............. 10.00

ADMINISTRATIVE REPORT 13

OCTOBER, 1923.
Herman Gunter, State Geologist, salary.....................$ 250.00
Herman Gunter, State Geologist, expenses .................. 16.80
Florence M. Epperson, Stenographer, salary ................ 110.00
Southern Telephone & Construction Co.... ................. 3.25
D. A. Dixon Co., supplies...: ......... .................. . 11.25
Wrigley Photo-Engraving Corporation, chart............... 5.31
Engineering & M ining Journal-Press ....................... 8.00
T he A m erican Fertilizer................................... 3.00
T he O il W eekly...................... ................... 1.00
M iddle Florida Ice Co..................................... 2.30

NOVEMBER, 1923.
Herman Gunter, State Geologist, salary ......................$ 250.00
Herman Gunter, State Geologist, expenses. ................. 46.93
Florence M. Epperson, Stenographer, salary ................. 110.00
Olin G. Bell, expenses..................................... 132.84
Southern Telephone & Construction Co...................... 3.25
American Railway Express Co............................. 2.44

DECEMBER, 1923.
Herman Gunter, State Geologist, salary ....................$ 250.00
Florence M. Epperson, Stenographer, salary ................. 110.00
Southern Telephone & Construction Co...................... 3.25
D. A D ixon Co., supplies.................................. 1.50
Wrigley Photo-Engraving Co., zinc etching .................. 5.50
American Railway Express Co ..................... ...... 1.25
E. Leitz, Inc., 1 Binocular M agnifier........................ 61.98

JANUARY, 1924.
Herman Gunter, State Geologist, salary..................... $ 250.00
Herman Gunter, State Geologist, expenses................... 91.68
D. Stuart M ossom, Assistant, salary ..................... ... 166.66
D. Stuart Mossom, Assistant, expenses ........ .............. 96.26
R. M Harper, Assistant, salary............................. 166.66
R. M Harper, Assistant, expenses.......................... 62.80
Florence M. Epperson, Stenographer, salary ................. 110.00
Southern Telephone & Construction Co...................... 3.25
Service Print Shop............... ........................ 17.75
FEBRUARY, 1924.
Herman Gunter, State Geologist, salary..................... $ 250.00
D. Stuart Mossom, Assistant, salary ........................ 166.66
D. Stuart M ossom, Assistant, expenses ...................... 44.46
D. Stuart Mossom, Assistant, auto mileage .................. 67.50
R. M Harper, Assistant, salary............................. 166.66
Florence M. Epperson, Stenographer, salary ................. 110.00
Southern Telephone & Construction Co...................... 3.25
H. & W B. Drew Co., supplies............................. 6.12
Florida State Historical Society, publication ............... :. 11.00
Economic Geology Publishing Co., subscription. ............. 4.00
W H. M ay, Postmaster, stamps............................ 50.00

MARCH, 1924.
Herman Gunter, State Geologist, salary......................$ 250.00
Herman Gunter, State Geologist, expenses .................. 60.46

14 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

D. Stuart M ossom, Assistant, salary......................... 166.66
D. Stuart M ossom, Assistant, expenses...................... 46.05
D. Stuart Mossom, Assistant, auto mileage .................. 169.70
R. M Harper, Assistant, salary............................. 166.66
R. M Harper, Assistant, expenses................ ......... 76.53
Florence M. Epperson, Stenographer, salary ................. 110.00
Southern Telephone & Construction Co...................... 3.25
American Railway Express Co.................. .......... 15.09
D. A D ixon Co., supplies....................... ......... 2.95
L. B. M marshall, copying tabulation.......................... 4.50
A. R. Livingston, map southern Florida ................ .... 5.00
W western Union Telegraph Co........................... .. 2.97

APRIL, 1924.
Herman Gunter, State Geologist, salary............... .....$ 250.00
D. Stuart Mossom, Assistant, salary ..................... ... 166.66
Florence M. Epperson, Stenographer, salary ................ 110.00
Southern Telephone & Construction Co...................... 3.25
American Railway Express Company ............. ........ 9.09
D. A. Dixon Company, supplies.................. .......... 6.00
Florida Democrat, double cards (3,000) ..................... 20.00
T J. A ppleyard .......................................... 2.25
W H. M ay, Postmaster, stamps............................ 75.00
W. C. Dixon, freight and drayage (15th Annuals) ........... 45.15

MAY, 1924.
Herman Gunter, State Geologist, salary.....................$ 250.00
D. Stuart M ossom, Assistant, salary ......................... 166.66
Florence M. Epperson, Stenographer, salary ................. 110.00
Southern Telephone & Construction Co...................... 3.25
American Railway Express Company ...................... 6.48
The Record Company, printing 15th Annual Report .......... 1,879.69
Commercial Fertilizer, subscription......................... 2.00
University of Chicago Press, subscription ................... 3.60

JUNE, 1924.
Herman Gunter, State Geologist, salary.....................$ 250.00
Herman Gunter, State Geologist, expenses ................... 38.90
D. Stuart M ossom, Assistant, salary ..................... . . . 166.66
D. Stuart Mossom, Assistant, expenses ...................... 3.60
Florence M. Epperson, Stenographer, salary ................. 110.00
Southern Telephone & Construction Co...................... 3.25
American Railway Express Company....................... 4.81
D. A. Dixon Company, supplies............................ 33.40
W. H. May, Postmaster, stamped envelopes. ................ 91.68
Grant Furniture Company................................. 39.00
Wm. Ainsworth & Sons, Brunton Compass .................. 32.50
Wagner Free Institute of Science, Veg. of South Florida ...... 2.50
Rand McNally & Company, 1 Atlas ......................... 9.06
M illhiser Bag Company, Inc., bags ......................... 45.91

N)

ELORIDA

SHOWING PRINCIPAL PHOSPHATE TERRITORY
AND APPROXIMATE LOCATION O0
VARIOUS OTHER MINERAL INDUSTRIES
BY HBERMAN GUNTR
1924

SHard Rock Phosphate

Land Pebble Phosphate

Lime, Limestone; marl
and crushed. flint Plants
Brick and Tile Flant$
0 Kaolin Plants
A Fuller's Earth Plants
SPotteries
a Sand and Gravel Plant6
+ Sana-Li e Brick Plants
Ilmenite,Rutlle,Zircon Plant
/\ Springs producing Mineral Waters

STATISTICS ON MINERAL PRODUCTION IN FLORIDA DURING 1923 17

STATISTICS ON MINERAL PRODUCTION IN FLORIDA
DURING 1923

HERMAN GUNTER

Collected in Cooperation with the United States Geological Survey and
the U. S. Bureau of Census

The total value of the mineral output in Florida during 1923, as
shown by returns from the producers, was $13,230,099. This is $1,785,-
026 more than the total value of production for 1922, or an increase of
a little over 15 per cent. The larger volume of increase comes from
the phosphate and the limestone industries, as can be seen by reference
to the table at the end of this chapter. The outstanding feature in the
State's mineral industries was the remarkable development made by the
limestone industry. The returns for 1923, as compared with those for
1922, show an increase of 98 per cent. Comparable to this are the re-
turns made for sand and gravel showing 96 per cent increase and for
crushed flint rock of 142 per cent. Since these products, limestone,
crushed flint and sand and gravel, enter so largely in the construction
of our highways as well as other structural purposes, these figures re-
flect the rapid development that Florida is making. The mineral indus-
tries of the State as a whole, as judged from the statistical returns,
showed decided improvement and enjoyed a very satisfactory business
year, some of them to the extent of establishing new high records of
production.
CLAY

The kaolin industry of Florida, which is centered in Putnam and
Lake counties, was very active as is indicated by a 28 per cent increase
in the value of the 1923 production over that for 1922. Another feature
is the preparation being made for the opening of a new mine at Crossley,
Putnam County, by the United Clay Mines Corporation of Trenton,
N. J. The Florida kaolin is an exceptionally high grade, very plastic,
white burning clay. The washed clay is shipped to potteries of the

18 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Northern States where it enters into the manufacture of the higher grade
white wares.
Owing to the limited number of producers, production figures and
value are not given separately but they are included in the total for
the State.
KAOLIN PRODUCERS, 1923 /
Edgar Plastic Kaolin Company, Metuchen, N. J., and Edgar, Fla.
Florida China Clay Co., Inc., Leesburg, Fla.
Lake County Clay Co., Metuchen, N. J., and Okahumpka, F'la.

CLAY PRODUCTS
There are a number of clay-working plants in Florida producing
principally common building brick. Some of the plants, however, man-
ufacture hollow building tile, drain tile and face brick. There are also
two potteries in the State producing art pottery of various shapes, such
as vases, bowls and other artistic clay pieces. Although the pottery
industry is a comparatively new one in the State, it constituted a little
more than 5 per cent of total value of clay products in 1'''.';. The total
value of the output of all clay products was : .,.,:, which is 7 per
cent more than that recorded for 1922.

BRICK AND TILE PRODUCERS, 1923
The Build-With-Brick Company, Molino, Escambia County.
J. M. & J. C. Craber, Campville, Alachua County.
E. M. Davis, Lawrence, Gadsden County. (P. 0. Ocklocknee.)
Dolores Brick Company, Molino, Escambia County.
Florida Industrial School for Boys, Marianna, Jackson County.
Gamble & Stockton Company, Jacksonville, Duval County.
Glendale Brick Works, Glendale, Walton County.
G. C. & G. H. Guilford, Blountstown, Calhoun County.
W. J. Hall & Son, Chipley, Washington County.
Hull & Cowan Company, Callahan, Nassau County.
Keystone Brick Company, Whitney, Lake County.
Tallahassee Pressed Brick Company, Havana, Gadsden County.
POTTERY PRODUCERS, 1923
Florida Pottery, 2107 Fourth St., St. Petersburg, Pinellas County.
Orlando Potteries, Orlando, Orange County.

FULLER'S EARTH
Fuller's earth is a clay possessing the peculiar properties of absorb-
ing coloring matters and through the process of filtration removing these
from mineral, animal and vegetable oils and fats. The Florida earth is
largely used in the refining of mineral or petroleum oils, but it is also
used to some extent in the clarifying of vegetable and animal oils. Ac-

STATISTICS ON MINERAL PRODUCTION IN FLORIDA DURING 1923 19

cording to the United States Geological Survey fuller's earth is "said to
be used in the manufacture of pigments for printing wall paper, in
detecting certain coloring matters in some food products, as a substitute
for talcum powder, 'and in medicine as a poultice and as an antidote for
alkaloid poisons."*
In the output of fuller's earth Florida maintains first place (as it
has since the beginning of the industry) in the list of States from which
commercial production is reported. Although the tonnage and value
is not given separately it is included in the total for the State. The
Southern States supply nearly all the domestic earth and of these Flor-
ida, Georgia and Texas are the leading, being credited with 92 per cent
of the 1923 production.

FULLER'S EARTH PRODUCERS IN 1923
Attapulgus Clay Company, Ellenton, Manatee County.
Floridin Company, Quincy and Jamieson, Gadsden County.
Fuller's Earth Company, Midway, Gadsden County.
Manatee Fuller's Earth Corporation, Ellenton, Manatee County.

ILMENITE AND ZIRCON
The production of ilmenite in Florida was begun by Buckman and
Pritchard, Inc., at Mineral City, about five miles south of Pablo Beach,
Duval County, in 191(i. This industry has continued and increased
until Florida is now ranked as one of the leading States in the output
of this mineral.
The sands along the Atlantic Coast of Florida to and probably south
of Palm Beach County contain ilmenite in varying proportions. It is
recovered, however, at only the locality mentioned where the sands are
sufficiently rich to warrant operations on a commercial scale. Minerals
other than ilmenite also occur and of these a small output of rutile, zircon
and monazite have at various times been reported. During the year
1923, however, ilmenite and zircon were the only two products reported.
Ilmenite is now largely used in the manufacture of white titanium
oxide, a pigment used in paints and also for the manufacture of certain
special grades of steel and other alloys. Zircon finds its chief use as a
refractory material, as for instance, in the manufacture of crucibles,
porcelain wares having to withstand high temperatures such as spark
plugs and electrical insulation and vitrified enamels. With continued

*Fuller's Earth in 1923, by Jefferson Middleton; U. S. Geol. Surv., Mineral
Resources of the United States, 1923-Pt. II. Oct. 17, 1924.

20 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

investigation and experimentation the uses of zircon will no doubt be
extended. The 1923 production figures indicate a 35 per cent increase
over those for 1922 and although these are not separately given they are
included in the State total mineral valuation.

LIMESTONE, LIME AND FLINT
The output of limestone in Florida in 1923 amounted to 1,412,410
tons and was valued at $1,236,226. These figures indicate an increase
of 115 per cent in quantity and 98 per cent in value over 1922. The
various purposes for which the limestone was used as reported by the
producers, were: Rock material, stone filler as in asphalt and other uses,
railroad ballast, riprap, building stone, and agricultural. The figures
given indicate the rapid progress Florida is making in the development
of permanent roads and along building as well as industrial lines. To
the above figures for limestone should be added the figures for lime and
crushed flint and miscellaneous stone which brings the total production
of limestone, quick-lime, hydrated lime, crushed flint rock and miscel-
laneous stone to 1,507,999 short tons, valued at $1,572,768, which shows
an increase in output of 82 per cent and of 83 per cent in value over 1922.
The following companies reported limestone in 1923:

Blowers Lime and Phosphate Company, Ocala, Fla.
Brooksville Quarries, Brooksville, Fla.
Commercial Lime Company, Ocala, Fla.
Cummer Lumber Company, Newberry and Jacksonville.
Crystal River Rock Company, Crystal River and Leesburg.
Halifax Rock Company, Volusia and Daytona. (Formerly F. F. Smith.)
Florida Lime Company, Ocala, Fla.
Florida Rock Products Company, Brooksville and Tampa.
Florida Shell Rock Company, Williston.
Marion County Lime Rock Company, Ocala.
The Maule-Ojus Rock Company, Ojus.
Mickler & McLeod Rock Company, Lacoochee.
Ocala Limerock Company, Ocala.
Ojus Rock Company, Ojus.
State of Florida, Pineola.
T. A. Thompson, Branford.
The Volusia Coquina Rock Company, Volusia.

STATISTICS ON MINERAL PRODUCTION IN FLORIDA DURING 1923 21

The following companies reported flint or miscellaneous stone pro-
duction in 1923:

F. J. Baird, Anthony.
Cummer Lumber Company, Newberry and Jacksonville.
Florida Hard Rock Corporation, Ocala.
Levy County Stone Company, Williston.
Long-Pasley Company, Williston.
McDonald Construction Company, Lakeland.
Polk County Rock, Clay, Sand Company.
A. T. Thomas Company, Ocala.

The following companies reported lime production in. 1923:

Commercial Lime Company, Ocala.
Florida Lime Company, Ocala.

MINERAL WATERS
The sales of mineral and spring waters in Florida in 1923 were very
much greater than in 1922, there being an increase of 69 per cent in the
amount sold and 130 per cent in the value of sales. There were eighteen
companies reporting an output of water for commercial purposes in
1923. The total sales amounted to 1,697,197 gallons with a valuation
of $131,781. Production was reported from the following springs or
wells in 1923:

Bracks-Get-Well-Spring, Bradenton, Manatee County.
Crystal Mineral Spring, White House, Duval County.
Crystal Springs, Crystal Springs, Pasco County.
Deep Rock Spring, West Palm Beach, Palm Beach County.
Egret Springs, Fort Pierce, St. Lucie County.
Espiritu Santo Springs, Safety Harbor, Pinellas County.
Flamingo Spring, Orange City, Volusia County.
Good Hope Mineral Spring, Jacksonville, Duval County.
Gra-Rock Well, Miami, Dade County.
Hampton Springs, Hampton Springs, Taylor County.
Heilbronn Spring, Starke, Bradford County.
Peerless Spring, Miami, Dade County.
Pipkins Mineral Well, Safety Harbor, Pinellas County.
Purity Spring, Tampa, Hillsborough County.
Saint Nicholas Mineral Springs, South Jacksonville, Duval County.
Su-no-wa Spring, Bryceville, Nassau County.
Wi-Wauchula Spring, Jacksonville, Duval County.

PEAT
Although there are large deposits of peat in Florida, only one plant
reported a small production in 1923. The peat marketed was sold as
a fertilizer ingredient. The value of the output is included in the total
value of the State's mineral production.

22 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

The following are producers of peat in Florida:
Florida Humus Co., 14 Wall St., New York, and Zellwood, Florida.
Robert Ranson, St. Augustine, Florida.
Standard Agricultural Chemical Corp., 2 Rector St., New York, and Fellsmere,
Florida.
PHOSPHATE
The quantity of phosphate produced in- Florida during 1923, as
compared with the quantity for 1922, increased a little over 23 per cent.
In comparative value, however, there was an increase of approximately
only 9 per cent. By reference to records of past years it is seen that the
1923 output was very nearly the same as for 1913. The value, however,
for the latter mentioned year was about 5- per cent greater than in 1923.
The reported total production for 1923 was 2,547,653 long tons with a
valuation of $9,059,427.
In the hard rock district conditions remained about as for the year
1922. Practically all of the hard rock phosphate is exported and con-
ditions in Europe, while in a measure improved, were far from normal.
There is, however, an apparent great need for phosphate in Europe, so
pressing in fact that the 1923 output amounted to 6 per cent more than
for 1922; but in value there was a decrease of 22 per cent.
Separate statistics on the production of soft rock phosphate begin
in 1918. The maximum reported output came the following year, since
which time production has gradually decreased until in 1923 no returns
were made for this variety of phosphate.
Land pebble phosphate constituted, 92.3 per cent of the 1923 output
and 88 per cent of the total value of phosphate produced in Florida.
Although conditions were far below normal in the pebble fields they
were much better than in the hard rock district. In 1923 pebble phos-
phate showed an increase of 20 .pei cent in output and 12 per cent in
value over that of 1922. .
Florida produced more than four-fifths, or 85 per cent, of the phos-
phate sold in the United States in 1923. Other States reporting produc-
tion of phosphate were Tennessee,:Kentucky, Idaho and Wyoming.
The following table gives the production and value of Florida phos-
phate rock from 1900 to 1923, inclusive. Since the beginning of phos-
phate mining in 1888 to the close of 1923. Florida has produced 46,626,-
172 long tons with a .total, valuation of $184,156,669. These figures are
in accordance with statistics collected by' the United States Geological
Survey and the Florida Geological Surveys

PRODUCTION AND VALUE OF PHOSPHATE ROCK IN FLORIDA, 1900-1923.
(Long Tons)

Land Pebble Hard Rock River Pebble Soft Rock Total
Year -- I 1 Q it
Quantity Value Quantity Value Quantity Value Quantity Value Quantity Value

1900.. 221,403 $ 612,703 424,977 $2,229,373 59,863 $ 141,236 ........ $....... 706,243 $ 2,983,312
1901.. 247,454 660,702 457,568 2,393,080 46,974 105,691 ........ ........ 751,996 3,159,473
1902.. 350,991 810,792 429,384 1,743,694 5,055 9,711 ........ ........ 785,430 2,564,197
1903.. 390,882 885,425 412,876 1,988,243 56,578 113,156 ........ ........ 860,336 2,986,824
1904.. 460,834 1,102,993 531,081 2,672,184 81,030 199,127 ........ ......... 1,072,951 3,974,304
1905.. 528,587 1,045,113 577,672 2,993,732 87,847 213,000 ........ ........ 1,194,106 4,251,845
1906.. 675,444 2,029,202 587,598 3,440,276 41,463 116,000 ........ ........ 1,304,505 5,585,578
1907.. 675,024 2,376,261 646,156 4,065,375 36,185 136,121 ........ ........ 1,357,365 6,577,757
1908.. 1,085,199 3,885,041 595,743 4,566,018 11,160 33,480 ........ ........ 1,692,102 8,484,539
1909.. 1,266,117 4,514,968 513,585 4,026,333 ........ ........ ........ ........ 1,779,702 8,541,301
1910.. 1,629,160 5,595,947 438,347 3,051,827 ........ ........ ........ ........ 2,067,507 8,647,774
1911.. 1,992,737 6,712,189 443,511 2,761,449 (a) (a) ........ ........ 2,436,248 9,473,638
1912.. 1,913,418 6,168,129 493,481 3,293,168 (a) (a) ........ ........ 2,406,899 9,461,297
1913.. 2,055,482 6,575,810 489,794 2,987,274 (a) (a) ........ ........ 2,545,276 9,563,084
1914.. 1,829,202 5,442,547 309,689 1,912,197 (a) (a) ........ ........ 2,138,891 7,354,744
1915. 1,308,481 3,496,501 50,130 265,738 ........ ........ .... ... ....... 1,358,611 3,762,239
1916.. 1,468,758 3,874,410 47,087 295,755 ........ ........ (b) (b) 1,515,845 4,170,165
1917.. 2,003,991 5,305,127 18,608 159,366 ........ ........ (b) (b) 2,022,599 5,464,493
1918.. 1,996,847 5,565,928 62,052 377,075 ........ ........ 8,331 147,103 2,067,230 6,090,106
1919.. 1,360,235 5,149,048 285,467 2,452,563 ........ ........ 14,498 196,318 1,660,200 7,797,929
1920.. 2,955,182 14,748,620 400,249 4,525,191 ........ ........ 13,953 190,551 3,369,384 19,464,362
1921.. 1,599,835 8,604,818 175,774 1,806,671 ........ ........ 4,419 20,153 1,780,028 10,431,642
1922.. 1,870,063 7,035,821 188,084 1,308,201 ........ ........ 446 3,500 2,058,593 8,347,522
1923.. 2,348,137 7,987,752 1 199,516 1,071,675 ........ ........ ........ .. ........ 2,547,653 9,059,427
(a) Included in land pebble.
(b) Included in hard rock.

24 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

PHOSPHATE MINING COMPANIES REPORTING PRODUCTION, 1923
American Agricultural Chemical Company, 2 Rector Street, New York City,
and Pierce, Florida.
American Cyanamid Company, 511 Fifth Avenue, New York City, and Brewster,
Florida.
Armour Fertilizer Works, Chicago, Illinois, and Bartow, Florida.
J. Buttgenbach & Company, 22 Ave. Marnix, Brussels, Belgium, and Dunnellon,
Florida.
C. & J. Camp, Ocala, Florida.
Charleston, South Carolina, Mining & Manufacturing Company, Richmond, Vir-
ginia, and Fort Meade, Florida.
Coronet Phosphate Company, 99 John Street, New York City, and Plant City,
Florida.
Cummer Lumber Company, 453 St. James Building, Jacksonville, Florida.
Dunnellon Phosphate Company, 106 East Bay Street, Savannah, Georgia, and
Dunnellon, Florida.
Florida Phosphate Mining Corporation, P. 0. Box 1118, Norfolk, Virginia, and
Bartow, Florida.
Holder Phosphate Company, 3352 Jefferson Avenue, Cincinnati, Ohio, and
Inverness, Florida.
Independent Chemical Company, Inc., 33 Pine Street, New York City, and
Bowling Green, Florida.
International Agricultural Corporation, 61 Broadway, New York City, and
Mulberry, Florida.
Loncala Phosphate Company, Ocala and Floral City, Florida.
Morris Fertilizer Company, 801 Citizens & Southern Bank Building, Atlanta,
Georgia, and Bartow, Florida.
Mutual Mining Company, 102 East Bay Street, Savannah, Georgia, and Floral
City, Florida.
Peninsular Phosphate Corporation, 215 Fourth Avenue, New York City, and
Fort Meade, Florida.
Phosphate Mining Company, 110 William Street, New York City, and Nichols,
Florida.
Southern Phosphate Corporation, 25 Broad Street, New York City, and Mul-
berry, Florida.
Southern Phosphate Development Company, Inverness, Florida.
Swift & Company, Union Stock Yards, Chicago, Illinois, and Bartow, Florida.

STATISTICS ON MINERAL PRODUCTION IN FLORIDA DURING 1923 25

SAND AND GRAVEL
In common with other construction industries the producers of sand
and gravel enjoyed a very satisfactory business year. This is reflected
by the 108 per cent increase in quantity and 96.3 per cent increase in
value. The total production of sand and gravel in 1923 was 513,245
short tons, valued at $290,082.

PRODUCERS OF SAND AND GRAVEL, 1923
Acme Sand Company, Eustis.
Alafia Sand and Shell Company, Tampa.
Escambia Sand and Gravel Corp., Flomaton, Alabama.
Florida Gravel Company, Quincy.
Interlachen Gravel Company, Interlachen.
Lake Weir Crystal Sand Company, Ocala.
Leesburg Sand and Supply Company, Leesburg.
Tallahassee Pressed Brick Company, Havana.
Tampa Sand and Shell Company, Tampa.
White Sand Company, Orlando.
SAND-LIME BRICK
For a number of years sand-lime brick have been produced in Flor-
ida. During 1923 there was an increase of 12 per cent in the number of
brick produced and an increase of 18 per cent in value. The production
and value are not given separately, but the value is included with the
total for the State.
SAND-LIME BRICK COMPANIES, 1923
Bond Sandstone Brick Company, Lake Helen.
Plant City Brick Company, Plant City and Citizens Bank Bldg., Tampa.

SUMMARY OF MINERAL PRODUCTION IN FLORIDA FOR 1922 AND 1923
1922 1923
Mineral Product. Quantity j Value Quantity I Value

Phosphate (long tons)
Land pebble ................... 1,870,063 $ 7,035,821 2,348,137 $ 7,987,752
Hard rock .................... 188,084 1,308,201 199,516 1,071,675
Soft rock ...................... 446 3,500 ......... .......

Total Phosphates .......... 2,058,593 $ 8,347,522 2,547,653 $ 9,059,427
Ball Clay, Fuller's Earth, Peat, Zir-
con, Ilmenite (short tons)........ 107,684$ 1,666,260 115,990 $ 1,782,718
Lime, Limestone, Flint (short tons).. 824,150 857,913 1,507,999 1,572,768
Common Brick, Pottery, Tile and
Sand-Lime Brick.................. ........ 368,149 ........ 393,323
Sand and Gravel (short tons)........ 246,849 147,924 513,245 290,082
Mineral Waters (gallons).......... 1,004,984 57,305 1,697,197 131,781
Total Value ................... $11,445,073 $13,230,099

A PRELIMINARY REPORT ON THE LIMESTONES AND
MARLS OF FLORIDA

By

STUART MOSSOM

Assistant State Geologist

28 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

TABLE OF CONTENTS
PAGE
Introduction ........ ......................................... ......... 33
Classification of Rocks ................................................. 35
Lim stone ............................................. ..... ..... 36
Varieties of Limestone Found in Florida ......................... . 40-41
Physical Classification ......................................... 40
Chem ical Classification ........................................ 41
Uses of Limestone and Lime ......................... ............. 41-49
Raw Lim estone ............ ..................... ............ 42-47
Road M material ............. ... ........................ 42
Concrete Aggregate ................. ...................... 43
Railroad Ballast .............................. ... .... 43
B building Stone ............................................. 44
Cem ent M making ................................... ........ 45
Agricultural Limestone and Lime ........................... 45
Quicklime and Hydrated Lime .............................. 46
Sand-Lim e Brick ............................... ........... 47
Chem ical Lim e ...................... ............ ............ 47-49
Glass ................................. ................... 47
Lim light ................................................. 48
W ater Softening ........................................... 48
Bleaching Pow der ......................................... 48
C eram ics .................................................. 48
Calcium Carbide .......................................... 48
Illuminating Gas and Ammonia ............................ 48
Sugar R efining ............................................ 49
T manning . ................................................ 49
Glycerine, Lubricants, Soaps, etc............................. 49
O their U ses ............................................... 49
Lim stones of Florida .................... ....................... . 50-62
O rigin ........................ .................. ......... .. 50
T exture ....................... .................. ............. 51
Structure .............................. ...................... 53
W gathering ................................................... 55
Secondary D position .......................................... 62
Topography and Geology ............................................. 65-110
T opography ................ ........... ..................... .. 65
Structure .................................................... 66
Stratigraphic G eology ............................................. 67-110
E ocene Series ................................................. 68-70
Ocala Limestone ........................................... 68-70
Oligocene Series ............................................... 71-77
M arianna Lim estone ....................................... 71
G lendon Form ation ........................................ 73
M iocene Series .............. ................. .............. 77-90
T am pa Form ation .......................... ... ............ 77
Chattahoochee Form ation ................................... 82
A lum Bluff G roup ........................................... 86
C hipola M arl ............................................. 87
O ak G rove Sand ........................................... 87
Shoal R iver M arl ......................................... 88
Choctawhatchee M arl ...................................... 89
Pliocene Series .......................................... 91-95
Caloosahatchee M arl ...................................... 91
N ashua M arl .............................................. 94

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA zu

TABLE OF CONTENTS-CONTINUED
PAGE
Pleistocene Series .......................................... 96-113
K ey Largo Lim estone .......................... ............ 99
M iam i O olite ................... ......................... 102
Key W est Oolite ................................... ..... 108
Coquina ................. .... ........................... i110
Description of Deposits by Counties................. ............... 115-186
A lachua ..................... ........... ....... .......... .. 115
Baker .................................................... 117
B ay ...................... ........... ........ .............. 117
Bradford .................................... ............... 118
B rev ard ..................................... .............. .. 118
B row ard ................... ................. ................ 121
Calhoun ..................................... .. ............. 121
C harlotte ............................ ............ .......... 123
C itrus ..... ........................ ....... ................. 124
C lay ................................... .. ................ .. 127
C ollier ........................................................ 128
Columbia ............... ........ ...... ............. ....... 129
D ade .................... ...... ...... .......... ............ 129
D eSoto .......................... ............... ........... 132
D ixie .................. ....... ........ ......... ........... 132
D uv al .......... ........................................... 133
Escambia .......... ........................... ........ 133
Flagler ............................... ................... 133
Franklin ......... .............. ........ ....... ........ .. 134
G adsden ............ ........ ... ... ............. ........... 134
G lades ....................... ................... .......... 137
H am ilton ..................................................... 137
H ardee ............................... ..... ................. 139
H endry ................................ ..................... 139
H ernando .............................. ..................... 139
H ighlands ............................ ....................... 144
H illsborough .................................................. 144
H olm es ............................... ...................... 145
Jackson ...................... .... ...................... 145
Jefferson ......... ...... .............. ..................... 151
L afayette ...................................................... 153
Lake... .. ................................. 153
Lee ............... ........................ .... ..... ... 154
Leon .................. ........... .............. ...... .... 154
Levy .. ................................................... ... 155
Liberty ..... .................................. ................. 156
M adison .......................... ........................ .. 157
M anatee .............. ........ .............. ... ........... 157
M arion ..................................... ... ......... ..... 158
M onroe .............. ......... ........ ...................... 165
Nassau ........... ............. ...... ... ............ .... 167
Okaloosa ...................................................... 167
Okeechobee .................................................. 169
O range ..................................................... 169
O sceola .... ........................ ........................... 169
P alm B each ........................ ... ...................... 169
Pasco ............... ......................................... 171
P inellas ............. ............... ........... .............. 172

30 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

TABLE OF CONTENTS-CONTINUED
PAGE
Polk ................................. ......... ............. 172
P utnam .......................................... ........... 172
St. Johns ................ ...................... ............. 173
St. L ucie .................. ................. ................ 173
Santa R osa ............................ ....................... 173
Sarasota ............................ ......................... 173
Sem inole ......................... ............................ 174
Sum ter ........................ ........... ................... 174
Suw annee .............................. .... ............... 174
Taylor ..................................................... 177
U union ........................................ ............... 178
Volusia .................................................... 178
W akulla ...................................................... 181
W alton ....................................................... 184
W ashington ................................................. 186
General Summary .......... ........................... ...... .... 190

LIST OF ILLUSTRATIONS
HALF-TONES PAGE
2. Wall Sink, in Ocala limestone, near Sumterville, Sumter County ......... 32
3. Ocala limestone. Pit of Connell and Schultz, near Pineola, Citrus County 42
4. House built of Key Largo limestone, Islamorada, Monroe County....... 43
5. Quarrying the Miami oolite for building stone near Miami, Dade County 44
6. Building constructed of blocks sawed from Marianna limestone. Marianna,
Jackson County ................................................. 45
7. Hydrating plant and limestone pit of Florida Lime 'Company, Zuber,
Marion County ................................................ 46
8. Near view of Ocala limestone in Connell & Schultz pit. Near Pineola,
Citrus County ......................... ......................... 52
9. Weathered Glendon limestone in sink-hole on Dunn property. Cedar
Grove, near Chipley, Washington County ......................... 55
10. "Rise" of the Santa F6 River, Alachua County......................... 60
11. Near view of Glendon limestone in Old Lyle quarry, Live Oak, Su-
w annee County .................................................. 63
12. Drainage canal west of Ft. Lauderdale ............................... 64
13. Outcrop of Glendon limestone on Suwannee River opposite Ellaville,
Suw annee County .............................................. 74
14. Glendon limestone in Falling Water sink, five miles south of Chipley,
W ashington County .................................. ........... 76
15. Tampa limestone in pit of Florida Rock Products Company, Brooksville,
H ernando County ............................................... 80
16. Exposure of Chattahoochee limestone on A. C. L. R. R. Near River
Junction, Gadsden County .................... .................. 82
16a. Upper part of Chattahoochee limestone at Victory Bridge (old Chat-
tahoochee landing) .............................................. 85
17. Typical exposure of Caloosahatchee beds, (Pliocene), Caloosahatchee
River ........................................................ 92
18. Digging Nashua marl for road material, DeLeon Springs, Volusia
C county ......................................................... 94
19. Marl and calcareous sand, Cape Sable, Monroe County................. 96
20. Reef rock overlain by marl, Knights Key, Monroe County............... 97
21. Coral head in Key Largo limestone, Marathon Key, Monroe County ..... 100
22. Drilling dynamite holes in Miami oolite. Naranja pit of Ojus Rock Com-
pany, D ade County.................... ........................ 103

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 31

LIST OF ILLUSTRATIONS-CONTINUED.
HALF-TONES PAGE
23. Quarry in M iami oolite, Dade County ............................... 104
24. Dredging the Miami oolite in Maule Ojus Rock Company pit, Ojus, Dade
County . .... : ................................................ 106
24a. Train load of road material (Miami oolite), Ojus Rock Co. pit, Naranja,
D ade C county ................................................... 107
25. Outcrop of coquina rock near lighthouse, Anastasia Island, opposite St.
Augustine, St. Johns County ...................................... 110
26. Coquina on shore of Mosquito lagoon, north of New Smyrna, Volusia
County ............. ............................................ 112
26a. Coquina in old pit near Indian River City, Brevard County............. 113
27. Ocala limestone in pit of Gainesville Lime Rock Company, Arredondo... 116
28. Shell mound on Indian Riyer opposite Melbourne ..................... 119
29. Coquina in Carl Fay pit, near Eau Galliec............................ 120
30. Ocala limestone in Crystal River Rock Co. pit near Crystal River....... 124
30a. Ocala limestone in hard rock phosphate pit, Ft. White.................. 128
31. Exposure of Miami oolite at Silver Bluff, near Miami.................. 129
32. Rear view of dredge in Ojus Rock Company pit, Ojus.................. 130
33. Miami oolite in pit of Ojus Rock Company, Naranja.................... 131
34. Coquina in county pit near Flagler Beach. ............................ 134
35. Chattahoochee limestone, exposed in pit Y mile east of Insane Asylum,
Chattahoochee .................................................. 135
36. Weathered Glendon limestone along the Alapaha river, near Jennings.. 138
37. Plant of the Florida Rock Products Company, Brooksville ............... 141
38. Cutting building blocks from Marianna limestone in pit of R. D. Daffin,
M arianna ................................................... . 146
39. Flint rock at the surface in the "Pinhook" section of Jefferson County.... 151
40. Glendon limestone exposed in Miccosukee Drain, 2V miles northeast of
L loyd .......................................................... 152
41. Ocala limestone. Pit and crusher of Florida Shell Rock Company, Wil-
liston .............................. ..... .................... 155
42. Pit of Florida Lime Company, Ocala ................................. 159
43. Ocala limestone in Ocala Lime Rock Co. pit, Kendrick .................. 161
44. Florida Lime Company pit No. 2 (old Oakhurst quarry). Ocala........ 163
45. Key Largo limestone in old quarry, Windlys Island.................... 165
46. Rock Spring, Orange County ......................................... 168
46a. Sandy coquina near Blowing Rocks, Jupiter ........................... 170
47. Glendon limestone in old Lyle quarry, Live Oak ...................... 176
48. Digging coquina in Halifax Rock Company's pit, Volusia............... 180
49. Boulders of limestone dugfr.om shallow depth. Near Woodville ........ 182
50. Ocala limestone near Duncan ........................................ 187
51. Flint crusher of "Levy County Stone Co., W illiston..................... 191
52. Graph showing value of limestone, lime and crushed flint produced in
Florida 1913-1923 ................. ....... ....................... 195

TEXT FIGURES '..
1. Solution of limeston .............. ................................. 54
2. Natural fbridg Jormhation by means of sink holes. ...................... 58
3. Natural bridge formation by means of sink holes ....................... 58
4. Natural bridge formation by means of sink holes ....................... 59
5. Natural bridge formation by means of solution channels ................ 61
6. Natural bridge formation by means of solution channels............... 61
7. Natural bridge formation by means of solution channels ................ 62
MAP.
W orkable limestone and marl areas ...................... ............... 114

Fig. 2. Wall Sink, in Ocala limestone, near Sumterville, Sumter County.

A PRELIMINARY REPORT ON THE LIMESTONES AND
MARLS OF FLORIDA

INTRODUCTION

This report is intended to bring before the people of Florida, and
others interested in that State, some knowledge of the native limestone
resources, their general character and' distribution. Time and funds
did not permit a detailed study, but it is hoped that this preliminary work
will be of value as an introduction to these rocks and will serve as a
foundation upon which further investigation may be based.
It was not possible to accurately outline and indicate separate
deposits with estimated tonnage available and other information con-
cerfling the limestone, for the individual will want to secure such data
himself before attempting economic development at any given place.
The aim of this report, therefore, is to aid such persons by outlining the
general areas wherein limestone and marl deposits in workable quantity
occur, and furnishing a brief sketch of the character of the separate
geologic formations that can be recognized in those areas.
Analyses have been made of the material from each formation in
different areas and will serve as a guide to the chemical nature of the
limestone. The first part of this paper discusses the subject of lime-
stones in general, their origin, classification and uses. The second part
takes up the limestones of Florida from several viewpoints and includes
a brief outline of the stratigraphy of the State. The last part of the
report discusses the limestone and marl deposits of the State by counties.

34 FLORIDA GEOLOGICAL SURVEY-16TITH ANNUAL REPORT

The field work for this report was begun late in February, 1924,
and carried on intermittently until October; in all about eighteen weeks
were spent in the field. During that time all the quarries, pits and
known typical exposures were visited and, naturally, many additional
locations were found in the course of the survey. At each location a
representative sample of the material was taken and from these the
more valuable were selected for analysis.
While the calcareous deposits of Florida have previously received
no specific attention, a great deal of general stratigraphic and paleon-
tologic work has been done and the results published in reports of the
State and national geological surveys as well as in various scientific pub-
lications.
The writer has drawn on these different sources freely and given credit
in footnote references in each case; the stratigraphic discussion in this
report is based largely upon the work of Messrs. G. C. Matson, F. G.
Clapp and S. Sanford as published in the Second Annual Report of the
Florida Geological Survey.
The writer wishes to express his appreciation of the aid given by
many individuals whose information and assistance contributed greatly
to the furtherance of this report. Mr. Herman Gunter, State Geologist,
and Dr. R. M. Harper of this department, drawing on their knowledge
of the State, aided greatly in planning the field work and at all times
their friendly criticism was extremely valuable.
Dr. C. Wythe Cooke, of the United States Geological Survey, spent a
few days in the field with the writer and did much to familiarize him
with the stratigraphy of West Florida. Miss Julia Gardner, also of
the United States Geological Survey, very kindly furnished a collection
of data on the status of the Alum Bluff group. Messrs. N. B. Davis and
Dan Dahle, Assistant State Chemists, made the analyses of the various
samples submitted and the results of their painstaking work adds much
to the value of the report. Mr. H. A. Hall, Testing Engineer of the
State Road Department at Gainesville, kindly permitted the use of many
analyses from his files. The owners and foremen of the many lime-
stone pits were all exceedingly courteous, interested in the work of this
department and were of much assistance.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS O1f FLORIDA 35

CLASSIFICATION OF ROCKS
In common use, the term "rock" refers to something hard and firm,
but geologically it is applied to all solid material of which the earth is
composed, whether hard and compact, as granite; soft and yielding, as
clay; or unconsolidated, as loose sand. The rocks which make up the
earth's crust may be divided into three classes: igneous, metamorphic
and sedimentary.
Igneous rocks are those which have solidified from a molten mass
at or near the earth's surface. Examples of this class are: granite,
gabbro and basalt. These are the primitive rocks and from them the
other two classes have been formed.
Metamorphic rocks are those in which the texture and mineral com-
position of the original rock, either igneous or sedimentary, has been
altered by heat, pressure or chemical agency or, as is usually the case,
by a combination of these. To this class belong gneiss, schist, quartzite
and marble.
Sedimentary rocks are composed of the fragments or materials of
older rocks, of any class, that have undergone disintegration on the
earth's surface, and have been deposited either on land or in water by
mechanical, organic or chemical agency, or any combination of these.
Rocks of this class can be seen forming today in lakes, streams or in
the ocean, just as they have in past geologic times. Examples of these
are limestones, sandstones, clays and marls.
All known rocks may be accounted for in the above classification.
The sedimentaries cover much more of the earth's surface than the
igneous and metamorphic, but, considering the total amount present in
the earth, the rocks of sedimentary origin constitute a very small pro-
portion. The earth was entirely composed of igneous rocks before
erosion and deposition began and theoretically might be said to consist
of a sphere of igneous rocks with a thin outer shell of sedimentaries.
The sedimentary rocks occur, as would be expected, only as an outer
coating on the earth's surface, though in some areas their aggregate
thickness is known to be many thousands of feet.
Much of the land surface is covered by loose material, such as sand,
clay, soil or a mixture of all three, the alteration products; beneath this
surficial mantle lie the more compact and less weathered rocks. Igneous
rocks occur in irregular masses of varying size and shape, whereas sedi-

36 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

mentary rocks lie in beds more or less horizontal at the time of depo-
sition, but often tilted, folded and crumpled by subsequent earth move-
ments. All rocks found in Florida belong to this sedimentary group,
and of these only limestones and marls will be considered in this report.

LIMESTONE

Chemically pure lime is the oxide of calcium (CaO), and is widely
distributed throughout -the earth's crust; it is present in almost all
rocks, igneous, metamorphic and sedimentary, though some of these
carry it in very small quantities. Chemically it is rather active and
therefore is not found native but always in combination with other sub-
stances, chief among which is the gas, carbon dioxide (C02), forming
calcium carbonate (CaCOs), the principal component of limestone, the
mineral calcite, clam, oyster and other marine and fresh-water shells.
Pure lime is not readily soluble in water but is soluble in water charged
with C02, i. e., carbonic acid, after the formula:

H20 + CO2 = H2C03
water carbon carbonic
dioxide acid
Rainwater absorbs C02 from the atmosphere and forms carbonic
acid, or water coming in contact with decaying vegetable matter in the
soil forms carbonic acid. Thus, water percolating through the soil is
charged with C02 and when this acidulated water encounters the cal-
cium carbonate it takes it into solution as calcium bicarbonate in accord-
ance with the following:
H2CO3 + CaCOs = CaH2 (C03)2
carbonic calcium calcium
acid carbonate bicarbonate
Still in solution the lime is delivered by streams and rivers to the
ocean where-it finds conditions favorable for deposition.
This deposition of the CaCO3 to form limestone is brought about
through two main processes: First, through the activity of organisms
that cause the precipitation of calcium carbonate (CaC03) in contact
with their soft tissues, i. e., the lime-secreting organisms. Second,
through chemical precipitation by either organic or inorganic agencies
that lead to the supersaturation of water with reference to calcium car-
bonate (CaCOs).

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 37

A large portion of the limestone deposits were probably formed in
the first manner, namely, by the secretions of living organisms: molluscs,
foraminifera, corals, etc. As these different organisms have died their
shells, practically pure CaCOa, have been deposited on the sea floor in
the bed of limestone then forming. By current and wave action most
of these shells have been broken into fragments before reaching their
final resting place, so that no trace of their original form is left; but
some have been laid down in quiet waters and there formed the shell
limestones, beds made up almost entirely of well preserved fossils.
Lime-secreting algae are also important in this organic formation of
limestones, but seldom is the structure of the seaweed preserved in the
rock formed. Thus algae no doubt contribute greatly to the amorphous
lime matter that fills the voids in coral reefs or between fossil forms.
Through the second process, that of chemical precipitation, much
limestone has been formed, and is being formed today in the shallow
tropical sea around southern Florida and the Bahamas. There are sev-
eral methods of chemical precipitation that are all active in the formation
of such deposits, but just what part each plays and how much limestone
is formed by each cannot be determined. It is obviously impossible to
determine the exact method of formation of any given part of a lime-
stone, but the different methods of chemical precipitation discussed
below are all actively contributing factors.

(a) Precipitation through contact with other chemical compounds.
The streams that carry lime to the sea take up large amounts in solution
until they are completely saturated, no longer have an excess of CO2 and
therefore no further solvent action on limestone. When such a stream
empties into the sea, the stream water takes into solution some chloride
and sulphate salts present in sea water which are much more soluble
than calcium carbonate (CaCO3) and therefore some lime is precipitated,
but the water is still saturated with the carbonate and bicarbonate of
calcium.

(b) Precipitation of calcium carbonate (CaCOs) from the sea by the
sun's heat. The sea waters around southern Florida are constantly
receiving large amounts of the carbonate and bicarbonate of calcium
and are saturated. Any means whereby the C02 can be driven off from
the sea water will leave a supersaturated solution and will precipitate
calcium carbonate (CaCO3). This may be done by the sun's heat, for

38 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

it takes only a slight rise in the temperature of the sea water to liberate
the CO2-a violent agitation of the water may help in releasing it
and result in precipitating calcium carbonate (CaCO3). The sun may
also accomplish this same end through the evaporation of sea water,
again, though in a slightly different manner, bringing about supersatu-
ration with reference to calcium carbonate (CaC03) and the resulting
precipitation. This evaporation need only be comparatively slight, for
calcium carbonate is quite insoluble and is the first precipitate from a
supersaturated solution of sea water. Should evaporation continue to
any great degree, as in the cut-off arm of a sea in an arid climate, rock
salt (NaCI) and gypsum (CaS04) in particular and other mineral salts
which are far more plentiful in sea water than CaCOs would be deposited
in such quantities that the CaCO3 would be completely masked.
(c) Precipitation of calcium carbonate (CaCO3) through the action
of bacteria. Working in the Tortugas Laboratories in 1910-12 the late
G. H. Drew found that there were present in the sea around southern
Florida and the Bahamas, great numbers of bacteria capable of convert-
ing the nitrates of sea water into nitrites and thence into ammonia.* It
has been known for a long time that the addition of a strong alkali, as
ammonia, to sea water would produce the precipitation of the carbonate
of lime so that the presence of such organisms accounted in part for the
chalky muds found forming off the Florida Keys and the Bahamas. The
latest work done on this problem is by N. R. Smith, of the U. S. Bureau
of Plant Industry.t In studying samples of the bottom muds around
the Bahamas he discovered that there were present, in addition to the
denitrifying bacteria, ammonifying bacteria which were -more active in
the precipitation of CaCOa. These latter thrive on the organic matter
in the bottom muds and in their growth produce CaCO3 from calcium
sulphate (CaSO4) under conditions where the denitrifying bacteria will
not, viz: in the absence of the nitrates. It has been contended that
denitrification will not take place in pure sea water. This may be true
of the upper layers of the sea, but the bacteria are bottom-living organ-
isms and the organic matter in the bottom muds acts as a nutrient. Just

*G. H. Drew-On the precipitation of calcium carbonate in the sea by marine
bacteria and on the action of denitrifying bacteria in tropical and temperate seas.
Carnegie Institution of Washington, Pub. 182, 1914.
tT. Wayland Vaughan, "Present status of studies on the causes of the precipita-
tion of the finely divided calcium carbonate." In Report of the Committee on Sedi-
mentation-issued by National Research Council, Washington, D. C., 1924.

A .PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 39

how large a part these bacteria play in the formation of calcium carbo-
nate (CaCOa) in the chalky oozes or muds seen forming off certain
islands around southern Florida or what part they may have played in
the formation of the chalky limestones of other geologic ages is not
known, but that they are a contributing factor to the formation of lime-
stone is beyond doubt.
Green plants which use considerable amounts of C02 will also bring
about the precipitation of CaC03 from a supersaturated solution. The
sea plants use C02 for food just as land plants do, but they must derive it
from the sea water; the withdrawal of the C02 from solution brings
about a natural concentration and the precipitation of CaCOa so re-
leased.
In an ideal case with all the methods enumerated above functioning,
the sea floor will be covered with more or less worn and broken shells,
and shell fragments, the remains of lime-secreting algae and a soft ooze-
like mass of calcium carbonate sent down through the different chemical
precipitations. This amorphous mass of finely divided particles of
CaCOs acts as a cement for the unconsolidated beds of shells or shell
fragments and tends to bind them together. Should the sea floor sink
and this bed be buried under newer sediments the increased pressure
causes further consolidation, as limestone will readily go into partial
crystallization under these conditions. On the other hand, should the
floor of the ocean rise and expose the bed, rain water will leach out the
CaCOa from the upper layers and redeposit it in the lower, and water
percolating through the body of soft rock will cause the CaC03 to par-
tially crystallize, thus again through semicrystallization bringing about
further consolidation. The degree of consolidation has much to do with
classifying limestones according to their texture, as can be seen from the
following types of limestones. The term "limestone" includes rocks
differing widely in color, composition, structure, hardness and texture.
The one property common to all is that of consisting chiefly of the min-
eral calcite, CaCO:a.

-10 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

VARIETIES OF LIMESTONE FOUND IN FLORIDA
BASED ON PHYSICAL CHARACTERISTICS
Semicrystalline limestone-A hard, rather compact limestone orig-
inally soft and dense, but recrystallized by the action of water. Fre-
quently this recrystallization has taken place about a fossil mass; some-
times the recrystallization is so complete that no original structure is
left and the resulting material is very hard, uniform and brittle. Many
examples of partial crystallinity are found in all limestone formations
of Florida that have been exposed to weathering or through which
ground water has percolated.
Fossiliferous limestone-Any limestone in which fossil shells or
other animal remains, such as bones, teeth, etc., are prominent. All
Florida limestones are fossiliferous in varying degrees.
Shell limestone-A limestone composed almost entirely of shells or
shell fragments. Parts of the Ocala are excellent examples of this type,
and also some of the younger formations. The coquina is of course a
classic example.
Chalky limestone-Partly consolidated limestone composed of mi-
croscopic shells. The Marianna limestone is mostly of this type.
Oolitic limestone-Limestone made up of tiny nodules or concre-
tions of CaCO3, resembling the roe of fish. Miami and Key West lime-
stones.
Sandy limestone-A limestone which has been deposited near the
shore with the result that the currents have carried in much sandy
material which has been incorporated in the main body of the limestone.
Northern parts of the Miami oolite, and parts of. the Alum Bluff for-
mation.
Cherty or Flinty limestone-Limestone containing nodules or bands
of chert or "flint." Chert is composed of silica (SiO2), and the nodules
have been segregated within the limestone. It is probably of secondary
origin, formed by the action of ground water from the spicules of silica-
secreting sponges and other siliceous matter scattered throughout the
deposit.
Marl-A somewhat indefinite or elastic term, but might be defined
as a soft earthy mass made up of variable" quantities of lime, clay, sand
and carbonaceous material. Part of the lime content is often in the

A PRELIMINARY REPORT ON THE LIMESTONES AND MARS OF FLORIDA 41

form of shells or shell fragments. Marl may be either of fresh-water
or marine origin and is designated accordingly.

BASED ON CHEMICAL COMPOSITION
High-Calcium limestone-A limestone which contains little or no
magnesium carbonate (MgCOs), and very little of impurities as iron,
silica and alumina. It generally carries 93%-99% or more CaCOs.
Magnesian limestone-A limestone containing variable percentages
of magnesium carbonate (MgCOa), up to the theoretical percentage
for a dolomite. (See below.)

Dolomite-A mineral composed of the double carbonate of mag-
nesium and calcium, (MgCO3. CaCO.). It contains 54.35% CaCO3
and 45.65% MgCOa.*

Arenaceous and Siliceous limestone-Siliceous limestones are those
which contain silica in any of its several forms; it may be present as the
spicules of sponges or as other organic forms or as sand grains. In
the latter case it is called arenaceouss" and is the same as "sandy lime-
stone."
Argillaceous limestone-A limestone which contains much clayey
material, as iron, alumina and finely divided silica. Like "sandy lime-
stone," it is formed near the shore where the currents have brought in
impurities to the limestone deposit there forming.
. All the Florida limestones, with the exception of the argillaceous
Chattahoochee, are high-calcium limestones. The weathered surface of
these may contain a varying percentage of magnesium, but the fresh
material probably will not carry more than 34-1/2%. Chert and flint
boulders occur on the weathered surfaces of almost all the Florida lime-
stones, but are much more abundant in the Ocala than in any other for-
mation.
USES OF LIMESTONE AND LIME
The uses of limestone and the commercial preparations derived
from it are too numerous and varied to receive any extended treatment
here, but a short list of the more important applications of this great
natural resource may not be out of place.

*Dana, E. S., A textbook of mineralogy, p. 358. John Wiley & Sons, N. Y., 1900.

42 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

RAW LIMESTONE
Road Material-Crushed limestone is extensively used in road con-
struction, both as a base and as surfacing material. In Florida, where
soft limestones are very abundant and harder limestone somewhat rare,
the common practice is to construct the foundation of soft pure lime-
stone finely ground o that when it is dampened and rolled it will set in
a hard uniform mass, leaving the minimum number of voids. This
base is then treated with oil and a hard surface put on. The surface
may be of several kinds-asphalt, penetration or hard limestone. Ex-
perience has shown that an unsurfaced soft limestone road or even one

Fig. 3.-Ocala limestone. Pit of Connell & Schultz, near Pineola, Citrus
County.

surfaced with hard limestone alone will stand up under ordinary traffic
reasonably well for a limited time, but after that will disintegrate rapidly.
Maintenance costs are high and the practice not satisfactory, for hollows
and ruts started by traffic are enlarged by rainfall and wash and then
hardened; if these worn places are patched with either soft or hard
limestone the newly laid material has no chance to cement and is soon
worn away, leaving the road in as bad condition as ever. The better
practice is to use a comparatively waterproof surface; the penetration
type has generally been found to be most satisfactory for heavily
travelled roads. In this type of surfacing hard rolled limestone or slag

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 43

is 'used, sandwiched between bituminous binders, to cap the soft lime-
stone base. T
Concrete Aggregate-Limestone is much used as a coarse aggre-
gate for concrete work; the size of the material depends naturally on
the character of work in which the material is to be used. Usually the
rock is graded from material that will pass a two and one-half-inch mesh
to that which will rest on a one-half inch. The requirements of such a
rock are that it be hard, tough and of a good crushing strength. There
are many deposits of limestone in Florida that meet the requirements;
flint is also used in many sections.
Railroad Iallast-For railroad ballasting a stone must have a high
crushing strength and must neither dust nor chip easily. Several dif-
ferent Florida limestones have proven quite adaptable for this purpose,
even though they may not come up to the highest desirable specifications
in every case. The Miami oolite from Ojus, the Key Largo limestone,
Glendon limestone from Lyle quarry north of Live Oak, the Ocala rock
from Crystal River and the Tampa limestone from Brooksville have all

Fig. 4.-House built of Key Largo limestone. Islamorada, Monroe County.

been successfully employed for this purpose. In general any concrete
rock will do for ballasting, hut the converse is not true; oftentimes.a
rock that will not quite meet the requirements for a concrete aggregate
can be used in railroad ballast.

44 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Building Stone-The Florida limestones as a class do not possess
the hardness and crushing strength of the older formations that occur
in the more northern States and are famous for their adaptability as a
building stone. Nevertheless considerable use has been made of the
native rock in this State, though this use has in most instances been
restricted to small farm buildings and outhouses. Notable exceptions
to this generalization are the old Spanish fort at St. Augustine, con-
structed of coquina; modern bungalows all along the East Coast made
of the same material, and the beautiful homes in and near Miami built
with the Miami oolite. Limestone from this last-named formation has
in recent years been employed on an increasing scale in construction
work locally; the court house in Miami, Halcyon Hall hotel, the build-
ings on the Charles Deering estate and scores of other fine homes as well
as foundations, sea walls, etc., are built of this native limestone.
The Marianna limestone and, in some localities, the Ocala, are quar-
ried on a small scale and cut into building blocks used locally in different
building uses, especially as house supports and in chimneys for frame
houses. Throughout other areas the weathered boulders of the different
limestone formations are used with cement in building rough founda-
tions or in building small rock cottages where a rustic appearance is

Fig. 5.-Quarrying the Miami oolite for building stone near Miami,
Dade County.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 45

Fig. 6.-Building constructed of blocks sawed from Marianna limestone.
Marianna, Jackson County.

desired. Limestones of the Glendon and Tampa formations are in many
places hard and durable enough for building purposes, but the limestone
occurs in too irregular lenses or masses to make a good building stone,
and these often are not homogeneous but contain many small voids due
to solution or fossil impressions.

CEMENT 'MAKING
Portland cement is the product obtained by burning to the point of
incipient vitrification a mixture of silica, calcium carbonate, alumina
and iron oxide, and grinding the clinker to a powder. The various ele-
ments are present in the raw material in certain definite quantities, so
that the mixture is nearly always an artificial one; seldom is a limestone
found that carries the various impurities in the proper proportions. The
principal ingredients are limestone and clay or very pure limestone and
argillaceous limestone. The Florida limestones are very pure (93-99%
CaCOs) and are widely spread, large and easily worked deposits; they
are very low in magnesium carbonate, which further adds to their de-
sirability as the principal ingredient in cement.

"AGRICULTURAL LIMESTONE AND LIME
Modern scientific farming has brought about the use of lime as a
fertizer. It-has been foupd that the application of lime, either in the

46 FLORIDA GEOLOGICAL SURVEY-16TII ANNUAL REPORT

form of raw limestone (CaCOa), hydrated lime (Ca(OH2), or quicklime
(CaO), will neutralize the acid content in certain "sour" soils and be
beneficial to a great number of crops; but there is much controversy as
to just which form of lime is best. Agricultural lime as produced in
Florida, at or about Ocala, and shipped throughout northern Florida and
southern Georgia, i made by simply grinding or reducing the soft Ocala
limestone to a povde.)

QUICKLIME AND HYDRATED LIME

Pure limestone is *expressed chemically by the formula CaCOa;
when this is heated to a temperature of about 9000 C. the gas, carbon

Fig. 7.-Hydrating plant and limestone pit of
Florida Lime Company, Zuber, Marion
County.

A PRELIMINARY REPORT ON THE LIMESTONE AND MARLS OF FLORIDA 47

dioxide (COz), is driven off, leaving pure lime (CaO), known com-
mercially as lump lime or quicklime. If this material is allowed to
remain exposed to the air for a sufficient length of time, it will crumble
to a powder, owing to the absorption of moisture or water from the
atmosphere by the lime to form calcium hydroxide (Ca(OH)2-air-
slaked or hydrated lime. This same process is more quickly accom-
plished by adding water to the lime as is done when slaking lime to
make building mortar. Lump lime has long been manufactured, chiefly
for use in the building trades. In the last ten to fifteen years hydrated
lime has come into increasing importance, because there are many
industries that use the lime in hydrated form and this hydrating can be
more accurately done by hydrators at the lime plant, thus eliminating
inconvenience and the risk of over or under-burning in the slaking by
unskilled workman. The various uses of lime are too well known to
do more than list them-plaster, mortar, agricultural purposes and with
Portland cement to make a more plastic mortar or a hard, smooth finish-
ing material, as well as other uses.
Sand-Lime Brick-Sand-lime brick have been on the market for
less than twenty-five years and in the last ten have shown an increasing
importance, due to refined methods and the better quality of the finished
product, that bids fair to make it a larger factor in future construction
work. This brick consists essentially of a mixture of lime and sand
molded to brick form and then subjected \to steam pressure which in-
creases the cementing power of the lime.

CHEMICAL LIME
The chemical and industrial uses of lime, either in the form of raw
limestone, quicklime or hydrated lime are almost without limit and
probably no list includes all of them. Below are given some of the
more important and better known uses:

Glass-In the manufacture of glass-window, plate, bottle, etc.-
lime is a very necessary constituent, for glass is composed, in the main,
of the silicates of sodium and calcium. The lime is generally introduced
in the form of pure high-calcium limestone and forms from 10% to
25% of the mixture, depending on the variety of glass. In some types
of glass, quicklime and hydrated lime are used to avoid giving off a
gas at high temperatures.

48 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Limelight-If a strong flame of intense heat is played on a stick or
small block of lime a dazzling white light is obtained. This type of
light is used in the spotlights of theatres and also in lighthouses and
the searchlights of vessels.
Water softening-A "hard" water is one in which calcium carbonate
(CaCO0) is held in solution by excess carbon dioxide (CO02). Any
means whereby this CO2 can be removed will precipitate the CaCO3,
which is quite insoluble; commercially this is done by adding hydrated
lime (Ca(OH)2. The CaO of this added mixture combines with the
excess CO02 in the water to form CaCO3, which together with the insol-
uble CaCOs present is removed from solution.
Bleaching powder-Lime enters into the manufacture of bleaching
powder, known as chloride of lime, as. it does into many other processes
in industrial chemistry because it is the cheapest base available; the
product is manufactured by passing chlorine gas over slaked or hydrated
lime, which has considerable absorbing power. The product is used as
a disinfectant, oxidizing agent, and in bleaching cotton fabrics.
Ceramics-Limestone, or in some cases, the oxide and hydrate of
lime, is used to a small degree in the manufacture of pottery arid por-
celain. The use of the lime is as a flux, for it has been found that in
wares burned at moderate temperature the lime tends to bring the
point of vitrification and fusion nearer .together; magnesia has been
found to be a more desirable base than calcium however. When the
ware is burned at a high temperature the gases given off by the decom-
posing carbonates are undesirable and so in this type of product the
oxide or hydrate is used. Into glazing processes lime sometimes enters
to absorb some of the sulphurous kiln gases, though magnesia again
seems to give better results.
Calcium carbide, which is the source of acetylene, a gas widely used
for illuminating and high-temperature flames, is made by fusing coke
and lime in an electric furnace.
Illuminating gas and ammonia-Ordinary illuminating gas is made
by the distillation of coal; the gas thus produced is passed through
water, which removes the ammonia and ammonia compounds; this solu-
tion is then treated with lime to break up the compounds, heated and
the gaseous ammonia is, driven off and collected. The illuminating gas
that has passed through the water contains many impurities, as carbon

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 49

dioxide and hydrogen sulphide, therefore this gas is passed through
slaked lime and the objectional gases removed.
Sugar refining-The juices extracted either from the sugar beet or
sugar cane contain impurities that would discolor the product or turn
some of it into an uncrystallizable glucose; therefore these juices are
heated almost to boiling in the presence of lime. This reacts with the
acids, breaks up organic compounds and forms various insoluble salts
which can be removed; unfortunately it also forms an insoluble salt with
the sugar itself, so that this must be treated with CO2, which breaks up
the lime-sugar compound, and combines with the lime to form calcium
carbonate, which is precipitated, leaving the fine crystalline sugar.
Tanning-Hides are soaked in lime water to loosen the hair, which
can then easily be removed by scraping.
Glycerine, lubricants, soaps, etc.-In the manufacture of materials
of this class lime is quite important, for by means of it the fatty com-
pounds can be broken up. Glycerine is liberated when the fats are dis-
tilled with lime in water; the lime "soaps" left by this process are mixed
with the heavy mineral oils and sold as lubricants, or else the residue can
be treated with sulphuric acid and the separated fatty acids used in
manufacturing soap, candles and other products of this class. kOther
industrial uses of chemical lime are: Paint manufacture; distillation of
wood to produce wood alcohol, acetic acid and acetone; manufacture of
paper, caustic soda and soda ash; calcium cyanamide and calcium nitrate,
of increasing importance as fertilizers; calcium arsenate; as an asphalt
filler and filler in the paper, textile and rubber industries; in manufac-
ture of various chemicals; in the metallurgy of iron, steel, mercury, gold,
silver, etc., and in many other industrial processes. The Florida lime-
stones are as a rule exceptionally pure (92-99%0 CaCO3), and the quick-
lime and hydrated lime made from them is a very fine product adaptable
to many of the above industrial uses, but the distance from manufac-
turing centers has kept them from being used extensively, though some
material for chemical use has been shipped as far north as Charleston,
S. C., and to points in Alabama and Georgia. Most of the Florida pro-
duction goes into road material and other construction uses.

50 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

LIMESTONES OF FLORIDA
The limestones of the various formations, their distribution, lith-
ology and other characteristics will be considered later in detail under
their formational names. But it is thought fitting, after the foregoing
general remarks on limestone origin and classification, to give here a
brief account of the origin, texture and structure of the Florida rocks.
ORIGIN
The Florida limestones were all laid down in warmntropical waters,
mostly marine, at no time deeper than 100 fathoms; it is probable that
most of the deposition took place at depths of 25-50 fathoms. Deposition
usually took place on a sinking sea-floor, which accounts for the thick-
nesses of the Eocene and Oligocene formations, but the seas in which
these deposits were formed were all shallow. During Pliocene and
Pieistocene time some of the deposits were formed in brackish and fresh
water of very shallow depth-50 feet or so-but the deposits so formed
are of no great extent. The periods of deposition were closed by the
emergence or partial emergence of the sea-floor; erosional agencies set
to work and a new formation began to be laid down. The crustal warp-
ings or deformations which caused the rising and sinking of the sea
bottom have been due to compressional forces acting at right angles to
the axis of the peninsula; these deformations have been comparatively
slight and gentle, and, since they have acted over such a large area, they
have had little local effect on changing the character of the limestones.
The- deformations of the Florida land mass have not always acted uni-
formiy over the entire region-often the movement has been differential
-so that an arm of the sea from the Gulf side might cover one part of
the peninsula, while at the same time another part might be under the
waters from the Atlantic side. Because of this, some formations with
different names in the Florida section are considered contemporaneous.
This is especially true of many of the shallow water limestones and
marls of the Pleistocene.
The ideal condition for limestone deposition is a rather quiet, shal-
low, clear, tropical sea, rich in dentrifying and ammonifying bacteria
and lime-secreting organisms, and receiving much CaCO in the run-off
from the chemical denudation of the surrounding well-wooded lands.
Conditions in southern Florida today are in general much like those
prevailing over this whole region in past geologic time, and it can be
seen that here these ideal conditions are largely realized. There is
much limestone on the land; waters become charged with C02 passing

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 51

over the large areas of decaying vegetable matter; because of the gentle
slope of the land, these waters are long enough in contact with the lime-
stone to take the CaCO into solution and then carry it on to the ocean.
Vaughan1 suggests that in proportion to estimates made in other parts
of the world, the amount of such material poured annually into the bays
and sounds of southeastern Florida may be between 4,000,000 and
5,000,000 tons. Thus we can see that the waters surrounding southern
Florida are receiving large quantities of lime, just as in the past the
warm waters covering all parts of the present Florida received lime
from land masses to the north, west and southwest.
It is very likely that the accumulation of lime in the older seas was
slower than in those of today, because the source of lime was farther
removed and these older formations probably did not yield their lime
as readily or copiously as do the softer, purer deposits of the present
Florida. From solution in the ocean the limestone has been precipitated
and deposited on the ocean floor. This precipitation has taken place both
chemically and through the action of organisms; bacteria, which by their
physiological processes, produce ammonia, which acts on the calcium
sulphate (CaSO4), a salt present in large quantities in sea water, and
forms CaCOa; lime-secreting algae are also especially abundant in the
warmer waters; corals, foraminifera, molluscs and other lime-using
organisms have contributed quite considerably to the deposits, and much
of the CaCO derived in this way is in the form of finely comminuted
shell fragments; in the quiet shallow-water deposits the larger organ-
isms have remained intact or in large fragments. Examples of this can
be seen in any of the shell marls, and indeed all Florida limestones are
very rich in these well-preserved fossil shells, but only in the deposits
formed in rather quiet, shallow water are they found in such quantities
as to make up the main body of the bed. Evaporation of sea water sat-
urated with CaCO3; heating by the sun thus driving off C02; green
plants that use C02, and partial chemical rearrangement whereby
streams laden with CaCOs from the land drop some of their chemical
load to take up more soluble salts which they encounter in the ocean-
all of these play their part in the formation of the Florida deposits.
TEXTURE
The term texture applies to the arrangement, size and shape of the
constituent particles of a rock.
'T. Wayland Vaughan: A contribution to the geologic history of the Floridian
Plateau, Carnegie Institution of Washington. Pub. 133, p. 135, 1910.

52 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

A limestone rock is made up of grains of limestone (CaCO3) and,
depending on the size of these, may be fine, medium or coarse grained.
When the grains are of microscopic size the rock is said to be "dense";
if the grains can be seen with the naked eye, the term "granular" is used.
As has been previously mentioned, the degree of consolidation greatly
influences the texture. Deposits of marl newly formed are unconsol-
idated, porous and exhibit "earthy" texture; should they be a little fur-
ther consolidated, though still porous, they are called "friable." The
degree of porosity depends on the size of the interstices; if large, the
rock is "coarsely porous"; if small, "'finely porous." Limestone made
up of shells, corals and other animal remains more or less broken up
by the erosional agencies which have assembled them, are called "frag-

Fig. 8.-Near view of Ocala limestone in
Connell & Schultz pit, near Pineola,
Citrus County.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 53

mental"; should the different particles be bound together by crystals of
calcite, the texture is "crystalline," the degree of crystallinity depending
on the completeness' of the crystallization. If the rock is without form
or exhibits no crystallinity it is "amorphous." Should all the particles,
grains, fragments and crystals that make up the rock be more or less
uniform the rock is "even-grained"; should there be considerable varia-
tion, "uneven-grained." All of the characteristics may be present in
one rock, so that it would not be unusual to find a limestone which was
"coarsely granular, friable, porous, fragmental and uneven-grained." In
fact, the more characteristics that can be recognized in a rock, the better
it can be described.
STRUCTURE
The term "structure" applies to the features of a body of rock or
formation as a whole rather than its constituent parts and includes both
original and secondary features. Original features are those that a
rock has at the time of deposition; secondary features are those which
have been acquired subsequently, usually through metamorphic agencies.
The limestones of Florida are all of Tertiary and Quaternary age,
therefore geologically young, and all lie within the Coastal Plain prov-
ince, a region of comparatively little crustal disturbance. They have
not been affected by metamorphic agencies (chiefly heat and pressure),
which have folded, faulted and crystallized the older limestones of the
northeastern States, and therefore to a large degree they exhibit original
textures and structures, in places altered somewhat by the action of
ground water.
If at the time of deposition conditions were continuously uniform
for a long time the deposit will show no differences in bedding or strati-
fication, but will have a "massive" structure. If bedding planes can be
seen a foot or several feet apart the formation is "thick-bedded"; if the
planes are only a few inches apart-"thin-bedded." The thinnest sep-
erable layers or sheets in a stratified rock are called "laminoe." These
are not often seen in most of Florida limestones but are quite noticeable
in the impure limestones and the marls that have undergone secondary
deposition. Sometimes within a formation it will be observed that the
bedding planes of particular beds instead of being parallel to the general
planes of stratification of the series, or nearly horizontal in Coastal Plain
formations, are inclined at considerable ,angles, changing markedly in
short distances and sometimes curved; this structure is known as "cross-

uniform as here drawn, but on I scale the honeycombed structure and tortuous irregular winding of these caverns cannot e shown t
If 1 I I > 1 I I1
A I I I I I !II I I I

Text Fig. 1.-The above sketch gives some idea of the solution of the soft Florida limestones and illustrates the manner in which sink- t4
holes, solution cavities, clay pockets, etc., are formed. These underground solution channels are probably not at all as regular and C
uniform as here drawn, but on this scale the honeycombed structure and tortuous irregular windings of these caverns cannot be shown to r
advantage. The solid black represents open cavern spaces, the dotted area the soil mantle of sand and clay. At the left of the sketch z
can be seen an open sink-hole formed by the falling in of the roof weakened by underground solution; at the right a sink-hole formed
in a similar manner but clogged by soil and debris. Solution channels formed by downward percolating waters are shown, many of 0
these are relatively shallow and filled with.sand and clay while others are narrower, open and reach down to the deeper lying caverns.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 55

bedding." Good examples of this are seen in the upper part of the
Miami oolite and in the sandy limestone that forms the backbone of the
barrier beach on which Palm Beach is located, particularly well exposed
in a road cut through the golf links. Cross-bedding usually indicates
deposition in shoal waters by rapid and shifting currents, and is liable
to occur in deltas, bars, spits or barrier beaches where the material is
dropped on the forward slope of an advancing deposit. "Cross-bed-
ding" is sometimes of aeolian origin; no examples of this are found in
the limestones as they were formed under water, but this seolian cross-
bedding can be seen in wind-blown sands that make up the dunes along
the East Coast. "Stratification" is the term applied to deposits where
the material has been well sorted during deposition. Often in the form-
ing of a limestone bed of any considerable thickness, there have been,
from time to time, slight changes in the character of the deposits, so
that a limestone formation may have streaks of clayey or sandy material
or layers of slightly discolored limestone, each indicating a temporary
change in deposition, this is called "banded structure."

WEATHERING

Water, aided by gases of the atmosphere and a warm temperature,
is constantly at work on the limestones, breaking them down into small

Fig. 9.-Weathered Glendon limestone in sink-hole on Dunn property. Cedar
Grove, near Chipley, Washington County.

56 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

particles and removing the CaCO3. This process of disintegration and
decomposition by natural agencies is known as "weathering."
Conditions in Florida, both climatic and geologic, favor rapid
weathering. Owing to a heavy rainfall there is much water present in
the ground; this rainfall, coupled with a warm subtropical climate, has
produced luxuriant vegetation and therefore, in turn, an abundance of
decaying vegetable matter. The limestones are in general all soft and
lying near the surface, as most of them do, are easily accessible to meteoric
waters.
The mineral calcite (CaCOa), which is the main constituent of
limestone, though not readily soluble in ordinary water, is acted on by
water charged with C02, the result of rain water falling through the
air or coming in contact with the decaying vegetable matter in the soil,
and in this way the CaCO3 is removed from the formation. Roots of
trees, vines and other forms of vegetation all aid in giving water access
to a limestone formation; water will also seep in along planes of weak-
ness. Since the limestones are so soft, the water will find its way
through the formation easily enough once it is started in any quantity,
so that the hole made by the roots of an overturned tree or the cracks
made by the roots of vines will serve to start an extended "pot-hole" or
solution channel. On a large scale, in time, a whole formation may be
eroded away by this process of weathering, all the CaCO3 being carried
off in solution by the ground water and only the insoluble impurities left.
In the case of a very pure limestone, a formation 100-200 feet thick may
entirely disappear, leaving only a relatively thin soil mantle of clay and
sand-the insoluble impurities of the limestones; should the limestone be
more impure the residual mantle will be thicker. If the rock outcrops on a
hillside or where there is a slope of considerable grade, there will prob-
ably be no mantle present since the material left by the weathering
process will have been washed down into a region of lesser slope and
there deposited. It is for this reason that limestone is often found at
or near the surface on rises and hills while in lower places or valleys
the rock is covered with a variably thick mantle of clay and sand. This
weathering of the soft limestones, both at the surface and underground,
hasfi advanced stages, greatly affected the topography and, in the initial
stages, produced peculiar and grotesque results.
To explain some of the more common phenomena caused by lime-
stone weathering, let us take a hypothetical case and follow it through.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 57

Imagine a soft rather pure limestone lying level, exposed at the surface,
and supporting a sparse vegetation; as rain water falls on it the CaCO:1
is leached out of the upper few inches and redeposited in the lower foot
or so because there are no channels or openings whereby the lime-
laden waters can escape. This results in an indurated layer of lime-
stone at the surface-such a layer is seldom more than 1-3 ft. thick in
the Florida rocks; examples of this can be seen in any surface exposed
limestone, particularly the Miami oolite and the Ocala limestone. This
first surface weathering and redeposition is not absolutely uniform and
often results in pitted, jagged, uneven surfaces as well shown by the
Miami oolite in the pinelands south and west of Miami. Here the rock
outcrops at the surface with no soil covering and makes walking ex-
tremely difficult; occasionally small debris-filled depressions 3-4 feet
deep are encountered, but for the most part the surface is made up of
rough, hard, uneven limestone. As the weathering continues, water
finds its way down the cracks made by roots or gathers in hollows
formed by overturned trees, and in time dissolves the limestone and
reaches ground-water level. As the result of this vertical solution, hol-
lows with an inverted cone shape are formed, or, in other cases, merely
a small channel extending from the surface to water level. As water
passes down these openings it seeps into the main body of the rock and
hardens the adjacent limestone. Often these channels are lined with
crystals of calcite and aragonite (pure crystallized CaCO3) deposited
by the descending waters. These hollows and channels later become
filled with clay, sand and debris washed in by heavy rains and floods,
as can be seen in exposures in almost any of the lime pits. In some
localities there may be only a few of these "pot holes," ranging up to
10 or 20 feet in diameter in an area of several hundred square yards;
while in others an equal area may be so honeycombed with small holes
(1 to 3 feet in diameter) that it is impossible to walk more than a few
feet without encountering one. Most of these small solution cavities
or holes only extend 8 to 10 feet below the surface, but many of them.
particularly the larger ones, reach down to water level and are a great
nuisance to the limestone operators since they must be cleaned out before
the main body of the rock can be mined. Waters percolating through
a limestone formation will often leach out the silica (SiO2) contained
in the deposit as the spicules of silica secreting sponges or in other forms,
and deposit it in old channels, thus forming the nodules and beds of
chert encountered in limestones.

58 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

In some instances the whole mass of a one-time soft limestone may
be so dissected by a large number of solution channels more or less con-
nected that the rock has become semicrystalline by the water permeat-
ing all through it. These channels may be only a few inches wide in
the upper part, but frequently near water level they form chasms 3 to 6
feet wide.

Text Fig. 2.-Early stage of solution; stream flowing in underground cavern
with sink-hole and roof weakened in several places.
Ground plan: Broken lines represent course of stream in underground cavern,
diagonal lines represent solid rock at surface; small open area represents sink
hole.

11 I

Text Fig. 3.-Solution has continued and the weakened roof has fallen in in
many places until now stream runs through line of sinks.
Ground plan as in Figure 2.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 59

Immmmmmm

Text Fig. 4.-Advanced stage of solution; all but one segment of roof has
fallen in, forming a natural bridge. Stream runs in narrow channel with
steep sides, but has become a surface stream covered in only one place by the
remaining portion of the roof.
Ground plan as in Figure 2.
The above ideal sketches represent one method of natural bridge formation quite
common in the soft limestones of Florida.

Fossil shells, should they be present in large quantities, act as a
center of crystallization; in the Ocala limestone especially, this phenom-
enon is well illustrated and many examples are seen where the fossil
masses are indurated and semicrystalline while the surrounding lime-
stone, locally sparsely fossiliferous, is still soft and unaffected. This
type of weathering takes place only as far down as ground-water level,
for by that time the waters have lost most of their acidity and power to
take any more CaCOs into solution and they join the ground water.
The principal work of the ground water, made up of this downward
percolating rain water, is to take material into solution, transport and
deposit it elsewhere. Where the solution has become concentrated along
a bed or channel it may form an underground stream in a cavern; such
a cavern may be several miles long and over a hundred feet in diameter.
As the roof of this cavern becomes weakened by the continuous wearing
away of the.limestone, it will fall in and form a sink-hole; this is well
seen in many parts of Florida, especially in the country around Gaines-
ville and bordering the rivers in the northern part of the State. In Flor-
ida the soft porous limestones are frequently covered by a rather thick
mantle of clay and sand which, though porous and permitting the water
to filter through, masks the limestone, so that these sink-holes are often
lined with clay and sand and the rock itself is not always seen.

FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Through the activity of underground waters natural bridges are
also formed, a well known example being on the main highway at Arch
Creek, 14 miles north of Miami. The principle of natural bridge for-
mation is quite simple, but often produces seemingly impossible results:
as the descending meteoric waters leach out the CaCOs and feed the
underground streams, the roof is weakened and finally falls in; this
progresses until the underground stream becomes automatically a sur-
face stream with here and there portions of the roof still in place. These
remaining segments are the natural bridges (see figures on pages 58 and
59). Another method of natural bridge formation is illustrated on pages
61 and 62 ; many of the "disappearing streams" of the State belong to this
latter type: a small sink or solution channel appears in the bed of a surface
stream and some of the water is drained off through it. As time goes
on this new drain will become increasingly larger until it has become
the main drain and only in flood times will there be sufficient water in
the stream bed to overflow it and use the old surface channel downstream
from the underground drainage opening. The water that passes beneath
the surface through an opening of this kind may appear some distance

Fig. 10.-"Rise" of the Santa Fe River, Alachua County. The stream
enters the ground two or three miles away, emerging again at this
point.

x60

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 61

farther on, pouring forth as a spring or as the "rise" of the river. Un-
doubtedly there are many bridges of this type that are not recognized since
they are of too great size, for all the land passed under by such a stream
must be a natural bridge, but on account of the length of the span and
the low height, such a phenomenon is seldom noticed by the casual
observer.
The weathering power of water is generally considered to stop at
ground-water level or slightly below; this may be true as a general state-
ment, but it seems certain from the meager evidence at hand that even
below water level some changes take place in the limestone. Most lime
operators cease mining when water level is reached, but two pits in the
vicinity of Ojus use dredges to mine the Miami oolite 20 feet or more
below water level and the material brought up is a hard, jagged lime-
stone, certainly differing from the oolite lying above water level. It
may be that this is explained by the ease with which calcite recrystal-
lizes, so.that even though water below ground-water level has lost most
or all of its solvent power, still its presence throughout the formation
will bring about a molecular rearrangement.

Text Fig. 5.-Flowing surface stream with a small part of the flow passing
out by way of a small subterranean solution channel.

Text Fig. 6.-Solution channel has grown larger and is now main drainage
except in flood time, when surface channel takes care of the overflow.

62 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Text Fig. 7.-Solution channel has dissolved the limestone and retreated up-
stream, leaving limestone mass (X) as natural bridge.
In a region of low relief, as Florida, the process here illustrated will not
continue beyond an advanced stage of Figure 6. The end result will be a
long natural bridge with a very low span.
The above sketches show on an exaggerated scale a second method of natural
bridge formation. (Modified after Chamberlain & Salisbury.)

Because of the geologic youth, the softness of the rock and the
low relief of the country, there are no huge caverns in Florida compar-
able to those found in Virginia, Indiana and Kentucky. Nevertheless,
in the high south central and northern portions of the State there are
grottoes of considerable size and the lime-sink region around Gainesville
offers mute testimony to the solvency of underground streams; that all
the limestones underlying the State have at some time been subjected
to this same action is evidenced by the repeated reports of drillers de-
scribing the "pockets" that they have passed through in the deeper lying
formations. In and north of the Marianna-Chipley area sink-holes and
grottoes are quite common and in southern Wakulla and Jefferson
counties as well as southwestern Taylor these phenomena accompanied
by disappearing streams are well shown.

SECONDARY DEPOSITION

Under "Weathering," the power of downward percolating water
to leach out lime and deposit it at a lower level, thus forming an indu-
rated top layer, has been discussed. This same process if carried on in
an area of fairly high relief sometimes will cause the whole deposit to
be hardened and made semicrystalline. Good examples of this are the
Ocala limestone at the Crystal River Rock Company pit and the Glendon
limestone in the old Lyle quarry just north of Live Oak. Both of these
formations were originally soft limestones, but through this leaching-out
process have been altered to semicrystalline. The No. 1 pit of the

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA

Fig. 11.-Near view of Glendon limestone in old Lyle quarry, Live Oak,
Suwannee County.
Florida Lime Company at Ocala is a third instance of this. Examples
of the partial working of this secondary deposition or redeposition are
found all through the Ocala limestone, the hardened masses occurring
very irregularly. There is some doubt as to whether this partial recrys-
tallization within the body of the deposit is due to redeposition, as surely
the indurated surface layers are, or is the recrystallization of calcite in
the presence of water. The latter is probably true of most of the irreg-
ular hardened masses in the Ocala limestone, but the hard material in
the Crystal River pit and Lyle quarry seems to be due to redeposition
since the whole body of rock is affected and in both cases a 10 to 15 foot
bed of loose, chalky, somewhat impure material overlies the deposit and
seems to be limestone from which much of the calcium carbonate has
been leached.
When a marl is subjected to this process the results are bizarre indeed.
Most of the marls in southern Florida are composed principally of
unconsolidated sand and clay with considerable quantities of shells and
shell fragments; when these marls are exposed at the surface much of
sand and clay are removed by erosion, but the heavier shell matter re-
mains, thus increasing the ratio of lime to impurities (silica, iron and
alumina, etc.) in the deposit. Gentle rains provide the water which
percolates down through the marl taking the lime into solution and de-
positing it at a lower level, because of the low relief of the country and

64 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

the activity of ground water this "lower level" may be only two or
three feet. Due to the quantity of impurities present in the marl the
resulting deposition is an impure limestone, often weathered into gro-
tesque shapes. This limestone is usually quite brittle, dense, rings under
the hammer and often shows considerable laminations, due largely to
the impurities, which, because of the interrupted, or rather, successive
deposition are not always horizontally parallel but may be curved, wavy
and often irregularly concentric.
In dredging the drainage canals in south Florida, marl is often
encountered which is an oozy mass so soft that it runs out of the dipper.
This marl is dumped on the spoil bank and soon becomes a hard brittle
rock that is very difficult to break up and remove. Throughout the

Fig. 12.-Drainage canal west of Ft. Lauderdale showing marl on spoil bank.

whole of extreme southern Florida and particularly in the Everglades
this same phenomenon is naturally exhibited, that is the material as
originally laid down was a soft, oozy marl, but owing to differing condi-
tions much of it has been hardened to an impure limestone. These masses
are not regular in areal distribution and probably the marls from
which they are formed are not, but it is almost impossible to trace out
the separate formations. All were deposited during Pleistocene time
and are essentially the same, consisting of variable percentages of CaCO.i
(limestone) and Si02 (sand), and show all transitions from the uncon-
solidated marl to the hard impure siliceous limestone.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 65

TOPOGRAPHY AND GEOLOGY
TOPOGRAPHY

All of Florida lies within the Coastal Plain province and is under-
lain by soft, chiefly calcareous formations of Tertiary and Quaternary
age. The highest elevation is only about 350 feet, but in spite of this
there is an unexpected variety of topographic expression.
Everywhere south of the northern end of Lake Okeechobee and
bordering the peninsula, farther north on both the Atlantic and Gulf
sides, are the lowlands, a strip of country of variable width all lying
below the fifty-foot contour line and composed mostly of Pliocene and
Pleistocene sands, limestone and marls. This section, which comprises
over one-half of the total area of the State, has been practically unaf-
fected by erosional forces and crustal disturbances and, except for sand
dunes and stream channels, lies on a level, in the same position as when
it was formed.
In parts of the upland section of the State the relation of erosion to
topography can be readily seen, for here the rainfall aided by humic
acids has had a solvent effect on the underlying limestones, thus pro-
ducing a characteristic solution topography rather difficult of descrip-
tion, for the topographic features seem to follow no regular lines, but
are a series of basins or depressions of variable width and depth with
accompanying hills of variable height and breadth. Two areas in par-
ticular are worthy of mention in the "highlands" which extend down
the axis of the peninsula and are underlain by calcareous material: the
"lime-sink" region which lies chiefly along the west flank and the "lake
region" trending toward the east side of the peninsular axis. In the
former the limestones lie near the surface and the process of solution
has resulted in a series of shallow dry or water-filled basins or fluctuating
temporary lakes connected by underground drainage. In the "lake
region" the limestones lie deeper and the lakes are not known to have
subterranean outlets and are of a more permanent nature.
In western Florida, including Escambia and Santa Rosa counties,
as well as in Gadsden and the northern part of Liberty counties, the
limestones lie at considerable depth and exert little or no influence on
the surface features. Here the topography is determined by natural
drainage courses and normal erosion,

66 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

STRUCTURE
The Floridian plateau, jutting out and separating the Gulf of
Mexico from the Atlantic Ocean, presents an unusual structural feature
in coastal plain geology. The exact time of its formation has not been
determined. Uniform sediments of Eocene (Jackson) age are wide-
spread over all of the peninsula and constitute the oldest exposed forma-
tion. From a broad, low-domed structurally high area in the northern
central part of the peninsula around Gainesville and Ocala, the Ocala
limestone, the oldest exposed formation in Florida, dips south and south-
west at about 6 feet to the mile; in the Tampa elibayment this dip seems
to be increased and the direction changed to south and southwest. The
younger formations resting conformably or with but slight unconform-
ities upon the Ocala seem to have the same general dip.
In that part of Florida west of the Choctawhatchee river the lime-
stones lie at considerable depth beneath the surface and there are not
enough well records to give any detailed description of the structural
conditions. It is probable, however, that with very low folds, the Ocala
dips gently toward the south and southeast.
Between the Choctawhatchee and Apalachicola rivers, with its axis
nearer the former, is a broad structurally high area that brings the
Marianna limestone (lower Oligocene) to the surface at the town of
Marianna and also exposes in the same area the underlying Ocala
limestone of uppermost Eocene age. From this point these formations
dip to the south and southeast, forming a broad shallow syncline or
trough between the Apalachicola and Ocklocknee rivers. East of the
Ocklocknee in southern Wakulla County and to the northeast around
Live Oak in Suwannee County are slight structurally high areas whose
extent and size are as yet not well defined. The mere presence of the
Ocala limestone at the surface does not, in itself, mean that there have
been crustal disturbances resulting in the formation of a broad anticline
or dome. Without a doubt erosion has played a considerable part in
molding the topographic features of the Floridian plateau; so that al-
though certain areas are considered structurally "high," erosion, as well
as crustal deformations, must be considered as an important factor.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARS OF FLORIDA 67

STRATIGRAPHIC GEOLOGY
The geologic column as discussed in this report is given below; the
exact position of many of these formations is somewhat doubtful, as
some are in large part contemporaneous. This matter is discussed more
fully in the text.

Coquina
Marls (undifferentiated)
Key West oolite
PLEISTOCENE Miami oolite
Key Largo limestone

(
I.

Nashua marl
Caloosahatchee marl

Choctawhatchee marl

Shoal River marl
Oak Grove sand
Chipola marl

Chattahoochee formation
Tampa formation

Glendon formation
Marianna limestone

EOCENE (Jackson)

PLIOCENE

MIOCENE

OLIGOCENE

Ocala limestone

68 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

EOCENE SERIES
OCALA LIMESTONE

Name-This name was first applied by Dall1 in 1892 to the Num-
mulitic limestone beds exposed around Ocala in Marion County. Eleven
years earlier Eugene A. Smith2 had given an account of limestone under-
lying large areas in western and peninsular Florida which he correlated
with the Vicksburg limestone of Alabama and Mississippi and to which
he applied the name "Vicksburg limestone."
Two years later, or in 1883, Heilprin described these Nummulitic
rocks and discriminated between them and the Orbitoides or Vicksburg
limestone, which both he and Dall considered to lie beneath the Num-
mulitic beds. In 1903 Dall3 proposed the abandonment of the name
Vicksburg as applied to the limestones of the Floridian peninsula and
the adoption of the name "Peninsular" for the former Vicksburg or
Orbitoides rock; this was done because the limestone that forms the
mass of the plateau was felt to be different from the typical Vicksburg,
possibly occupying a position intermediate between it and the Ocala.
In 19094 Matson and Clapp, and later in 19135 Matson and Sanford
followed Dall's opinion and considered, with exact correlations doubtful,
the Ocala limestone to overlie the "Peninsular" and the Marianna and
included all three in the Vicksburg group of Upper Oligocene age.
In 1915 Cooke6 gave the results of a study of these formations in
the course of which he discovered the Marianna-Ocala contact on the
Chipola river near Marianna and thus determined the correct strati-
graphic position. On paleontologic evidence he assigned the Ocala
limestone to the upper Eocene (Jackson), quoting from his paper: "It
has been shown that the'Ocala limestone is the equivalent in age of the
upper part of the Jackson formation as defined in Alabama and Missis-
sippi and that it underlies Vicksburgian limestone in western Florida.

1Dall, W. H.: The Neocene of North America. U. S. Geol. Survey Bull., 84,
pp. 103-104, 1892.
2Smith, Eugene A.: On the Geology of Florida. Am. Jour. Sci., 3rd ser., vol.
21, pp. 292-309, 1881.
3Dall, W. H.: Wagner Inst. Trans., vol. 3, pt. 6, 1903.
4Matson, G. C., and Clapp, F. G.: Florida Geol. Survey, 2nd Ann. Report, 1909.
5Matson, G. C., and Sanford, Samuel: U. S. Geol. Survey, Water-Supply Paper,
319, 1913.
6Cooke, C. W.: U. S. Geol. Survey Prof. Paper 95, i, 1915,

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 69

As the relations are conformable, the Oaala must represent at least the
upper portion of the Jackson formation, but whether the lower portion
of the Jackson in peninsular Florida is different from the Ocala, either
lithologically or faunally, is at present unknown."
In this report all the soft pure limestone found in the State bearing
Lepidocyclina, Orthophragmina and other associated fossils character-
istically present at the type locality in the rocks near Ocala is considered
to belong to that formation.

Lithologic description--The Ocala consists of a light-colored almost
white, cream-yellow to gray very pure limestone. When fresh this rock
is cream-white, soft, porous and granular, but on exposure to the air
may bleach out chalk-white. Because of its softness and porosity it
readily permits the formation of solution channels and pot-holes by
descending water, with the accompanying leaching out and redeposition
of CaCOa. Thus, some of the limestone, especially that exposed at the
surface, is hard and semicrystalline and throughout the main body of
the rock, about masses of fossil shells, which occur in great profusion,
and where water has percolated downward, the limestone may also be
of a semicrystalline nature. Nodules and layers of chert occur and in
some localities a large part of the surface rock has been silicified. The
rock is extremely uniform in texture and chemical purity, and it has
been known to run as high as 99.6 per cent CaCOs.
Paleontologic description-The Ocala contains many Orbitoides
(chiefly of the genera Orthophragmina. and Lepidocyclina), Numimulites
and other foraminifera as well as bryozoa, molluscs, echinoids and gas-
tropods. The most common molluscan and echinoid forms found in
this formation and more or :less peculiar to it are: Amusium ocalanumn,
Plicatula (Ocala sp.) Pecten perplanus, P. suwanneusis, Cassidulus
haldermani and C. wetherbyi.
The foraminifera are exceedingly abundant in the Ocala limestone
and in many places make up the main body of the rock; particularly
abundant and characteristic are: Lepidocyclina ocalana Cushman (macro-
and microspheric forms), L. floridauna Cushman, and L. ocalana var. sub-
decorata Cushman.
Structure and thickness-No complete section of the Ocala has ever
been taken, as the lower boundary is nowhere exposed. The greatest

70 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

thickness observed was at the quarry of the Crystal River Rock Company
near Crystal River, Citrus County, where there is a working face of
115 feet. Well records are unreliable, but judging from lithology alone
the thickness given by several deep borings in various parts of the State
is from 150 to 400 or more feet. The Ocala, from a structurally high
area around Gainesville and Ocala, dips very gently to the south and
southeast. To the north of this area and in western Florida east of the
Apalachicola river are other slightly high areas as explained under
"Structure" at the beginning of this chapter.
Physiographic expression-Because of its softness and porosity,
the Ocala has given rise to a topography marked by sink-holes, caves,
underground channels, disappearing streams and large springs. Silver
Springs, a few miles east of Ocala in Marion county, pours forth from
this limestone, and many of the temporary lake basins have been formed
in it. Its influence is strongly felt in the Payne's Prairie region south-
east of Gainesville, and in general all through this central portion of the
State. Natural Bridge, Natural Cave and the rock masses around
Waddell's Mill Pond in Jackson county north of Marianna are all in
Ocala limestone, considerably altered by weathering.
Areal distribution-Although the Ocala limestone presumably
underlies the whole State, it has in comparison only a small areal extent.
It is exposed in the northern part of Jackson county, and in the center
of the State it outcrops or immediately underlies a large area consisting
of southern Suwannee, eastern and southern Lafayette, western and
southern Union, western Alachua and Marion, northern Hernando and
practically all of Dixie, Levy and Citrus counties. (See Map.)
Economic uses-The greatest tonnage of Ocala limestone quarried
goes into highway construction, though one plant quarries a hard phase
of the stone for railroad ballast and three plants use the rock in the
manufacture of agricultural, hydrated, lump and quicklime. Once on
the market as hydrated or quicklime the material has innumerable uses
in the building, chemical and industrial world. As one of the principal
ingredients of Portland cement this rock would be of considerable value
because of its low magnesium content and other impurities as well as for
its softness, the size, accessibility and uniformity of the deposits.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 71

OLIGOCENE SERIES
MARIANNA LIMESTONE
Name and Stratigraphic Position-The name Marianna limestone
was given by Matson and Clapp in 1909 to the "soft, porous, light-gray
to white limestones of western Florida, which are characterized by an
abundance of Orbitoides mantelli and other foraminifera associated with
many other fossils, prominent among which are Pecten poulsoni and P.
perplanus."I
The formation received its name from the type locality, around the
town of Marianna in Jackson County, Florida, where for many years
the limestone has been sawed into building blocks used principally in
building chimneys, so that popularly the limestone is called "chimney
rock." Matson and Clapp distinguished it from the Ocala and "Penin-
sular" limestones, believing it to underlie these; all three formations
being placed in the Vicksburg group of lower Oligocene age; the exact
correlations were doubtful. In the stratigraphic discussion it was in-
cluded with the "Peninsular" limestone because of the close lithologic
resemblance and the 'fact that no defining contact had been found. In
reporting thickness the two formations were again given together or
in many instances simply called "Vicksburg limestone." These thick-
nesses ranged from 225 feet at Quincy to 250 feet at Alachua and 325
at Bartow.
Since that time additional work has been done on these pure soft
limestones which has solved many of the problems of stratigraphic rela-
tionship. Cooke2 gives the section on the Chipola river at Marianna
where he found 33 feet of the Marianna limestone resting upon the
Ocala. The discovery of this contact made clear the stratigraphic
relation of the Marianna to the Ocala, as well as giving the first definite
thickness to the Marianna formation. The Marianna is now considered
to represent in Florida the lowermost formation of the Vicksburg group
of lower Oligocene age, and, at the type locality, to rest conformably
upon the Ocala of Eocene (Jackson) age.
Lithologic description-The Marianna is a very pure, soft, chalk-

1Matson, G. C., and Clapp, F. G.: Second Annual Report of the Florida Geo-
logical Survey, p. 52, 1909.
2Cooke, C. W.: "Age of the Ocala Limestone," U. S. G. S. Prof. Paper 95, i,
p. 109, 1915.

72 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

like limestone, quite close-even-grained and exceedingly homogeneous.
When fresh it has a slightly cream-yellow appearance; sometimes this
discoloration is in streaks, but upon exposure to the air and sunlight the
limestone bleaches out to a chalk-white. Though not quite as pure as
the Ocala the Marianna will analyze 93%-95% in CaCOa. Along the
Chipola river or in other stream bottoms where the formation has been
exposed to the long continued action of water and other weathering
agencies, the normal soft "chimney-rock" phase has been altered to a
hard and compact light-colored limestone, in places locally semicrys-
talline. Because of its fine, even texture and homogeneity the stone has
for years been sawed out by hand with regular timber saws and used in
the construction of chimneys, house supports and, lately, as a regular
building stone. The stone in its natural occurrence is quite "damp" and
easily cut, so that simply by the addition of a small steady stream of
water at the sawing surface it cuts smoothly and uniformly.
Paleontologic description-The Marianna at and around the type
locality is not abundantly fossiliferous, and no critical study of complete
collections has been made, so that not a great deal is known of the fauna.
Probably the most characteristic fossil is the large orbitoid foraminifer
Lepidocyclina inantelli (Morton). Pecten poulsoni (Morton) also
occurs, but ranges through the entire Vicksburg group and is not re-
stricted to the Marianna; Clypeaster rogersi (Morton) has also been
reported from this locality, but it, too, ranges through the entire Vicks-
burg group and is not restricted to the Marianna.
Structure and Thickness-The 33 feet of the Marianna as exposed
at the type locality is the greatest known thickness attained by this for-
mation in Florida. In structure, the formation is of too limited areal
extent and too greatly eroded to secure any definite data. It seems to
lie practically horizontal, or, following the underlying Ocala, have a
slight dip to the south and southeast.
Physiographic expression-As would be expected of such a pure
soft limestone, the Marianna shows a surface topography greatly influ-
enced by solution and characterized by caves, irregular depressions,
rounded hills and underground streams, as evidenced by the springs
pouring forth from the limestone. In many places the formation is
covered by a thick mantle of sand and sandy clay and here the country
takes on a more rolling appearance with gentle slopes, as in Rabb's
valley southeast of Chipley.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 73

A4real Distribution-In areal extent the Marianna is one of the
smallest formations in the Florida section, its occurrence being noted
in but one county, Jackson, and only in a relatively small area there.
The outcrop of this formation is in shape roughly elliptical on a northwest-
southeast axis, with the town of Marianna in the center; north of this
place the limestone extends only three or four miles and a much less dis-
tance to the south ; to the east about seven and to the west, just beyond
Cottondale. To the northwest the limestone can be seen in scattered out-
crops on the Marianna-Campbellton road up to about three miles south of
Waddell's Mill Pond. The Marianna here must not be confused with the
Ocala, which is seen along the same road but two or three miles farther
north. In this vicinity both formations have been quarried on a small
scale for chimney blocks and may be confused upon hasty examination.
The limestone at and around Duncan in Washington County is now
known to belong to the Ocala formation, and the rock in the vicinity of
Chipley and southeast of there is now referred to the Glendon: both of
these localities were formerly believed to belong to the Marianna.
Economic Uses-The popular name, "chimney rock," gives a clue
to the most important economic use of this soft limestone. For years,
farmers in the vicinity of Marianna have sawed out slabs of soft stone,
piled the "green" blocks up to season them and built chimneys, house
supports and in many instances whole buildings of this chalk-white
stone. So far as is known the rock has been very little if ever used for
road material, in the manufacture of quicklime or any of the numerous
uses of a soft pure limestone; this has probably been due to many
different reasons, chief among which are the limited demand and the
quantity and accessibility of substitutes.
GLENDON FORMATION
Name-The Glendon formation was named by Cooke1 from a vil-
lage in Clarke County, Alabama, and was first described as the Glendon
limestone member of the Marianna limestone. Upon further investiga-
tion it was found that beds of Glendon age have a wider distribution
than the typical Marianna, that they transgress older formations and
contain a large and characteristic fauna, so that now the Glendon is
regarded as of formational rank.2
1Cooke, C. W.: "Correlation of the deposits of Jackson and Vicksburg ages in
Mississippi and Alabama." Journal, Washington Academy Science, vol. 8, p. 195, 1918.
2Cooke, C. W.: "The Correlation of the Vicksburg Group." U. S. G. S. Prof.
Paper 133, p. 3, 1923.

74 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Much of the "Hawthorne formation" of Dall3 as well as most of
the limestone in north and west Florida formerly considered Chatta-
hoochee are now included in the Glendon. Dall referred the limestone
exposed in the Suwannee river at Ellaville to the Hawthorne and also
the thin boulder beds found in the phosphate workings at High Springs
and other points in this vicinity. The type locality was near the town
of Hawthorne in Alachua County where the silicified and cherty lime-
stone was formerly quarried. He noted the frequent occurrence of thin
silicified boulder beds as the sole representative of this formation in
peninsular Florida and the occurrence of "an echinoid belonging to the
genus Cassidulus," in the limestone at White Springs and elsewhere.
This seems without a doubt to be the Cassidulus gouldii (Bouvy) which
is quite profusely distributed throughout the Glendon formation and,
so far as is known, limited in occurrence to this one horizon.
Stratigraphic Position and Thickness-Stratigraphically the Glen-
don conformably overlies the Marianna (though the actual contact has
not been seen in Florida), and represents in this State the uppermost for-

Fig. 1 3.-Oulerop of Glendon limestone on Sunannee Riher, opposite Ellaville,
Suwannee County.
3Dall, Wm. H.: "The Neocene of North America." U. S. Geol. Survey, Bull.
84, pp. 105-123, 1892.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 75

mation of the Vicksburg group (Oligocene). On the Suwannee river
at Ellaville the Glendon limestone can be seen resting unconform-
ably upon the Ocala limestone. The bas6 of the Glendon is not exposed
in the western part of the State, and consequently no accurate measure-
ments of the thickness can be given. In sink-holes southeast of Chipley
the exposed thickness varies from 38 feet to 45 feet. At Falling Water
southwest of the same town the formation has an exposed sheer face of
66Y2 feet; this latter is the greatest thickness observed.
Lithologic description-.The Glendon consists of two facies-where
the cover has been removed and the weathering active, the formation is
represented by thick beds of variegated red-yellow residual sands and
clays, usually light-colored, with lumps of chert; this phase is well de-
veloped in northern Holmes County, particularly in the country border-
ing the Choctawhatchee river.
Under cover or where the weathering agencies have not been so active
the limestone phase is seen. The Glendon limestone is soft, pure and
compact, cream to light yellow in color when fresh and bleaching out
chalk-white. It is largely made up of the shells of foraminifera and other
minute organisms, these harder particles bound together by soft amor-
phous lime material, with the result that the whole mass is much more
compact and not at all as granular or powdery as the Ocala limestone.
When struck with the hammer the stone fractures irregularly and in
all directions, leaving rough, jagged faces. Weathering agencies act
easily on this limestone, as is evidenced by the hard, tough cavernous
surface boulders in the west Florida exposures. In the vicinity of Live
Oak, Suwannee County, the whole limestone mass has been altered and
made semicrystalline by these weathering agencies to a depth of at least
forty feet. This limestone so affected is not uniformly hardened, but
consists of irregular rounded and lenticular masses of semicrystalline
material with interspaces of somewhat softer material. Northward all
along the Suwannee river and particularly in the vicinity of Suwannee
Springs this hardening of the limestone by water action can be seen.
Paleontologic description-The fauna of the Glendon has not been
fully studied, but from. the work done so far only one form, an echinoid
Cassidulus gouldii (Bouv6) is considered restricted to the formation.
The following1 species occur in the formation:

1Ibid., p. 7.

76 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Lepidocyclina chattahoocheensis (Cushman).
Lepidocyclina supera (Conrad).
Ostrea vicksburgensis (Conrad).
Pecten poulsoni (Morton).
Pecten n. sp. aff. P. poulsoni (Morton).
Pecten anatipes (Morton).
Pecten n. sp. aff. P. gabbi (Dall).
'Spondylus dumosus (Morton).?
Pteria argentea (Conrad).
Clypeaster rogersi (Morton).
Calcareous algae.
Bryzoa.
Areal Distribution and Dip-Most of the area in northern Florida
formerly mapped as Chattahoochee is now considered of Glendon age.
The formation outcrops in a wide belt over most of northern Holmes
County, part of northeastern Washington and southern, southeastern
and southwestern Jackson. The limestone phase is present in a com-
paratively small area around Chipley in northeastern Washington
County; dipping gently to the southeast it passes out beneath the sands

Fig. 14.-Glendon limestone in Falling Water sink, five miles south of Chipley,
Washington County.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 77

and clays of the Alum, Bluff. Just east of the Chattahoochee river the
Glendon has not definitely been traced; it probably lies below the Alum
Bluff sediments here and does not appear at the surface. Outcrops of
this lintestone are seen in the vicinity of Lake Miccosukee in northern
Leon and Madison counties and to the east all the rivers, Withlacoochee,.
Alapaha and Suwannee, have cut down through the younger beds and
have their channels in the Glendon limestone. In the area around Live
Oak to the east and north, the Glendon lies very close to the surface and
outcrops in many places. East of Live Oak the Glendon is again cov-
ered by Alum Bluff deposits; to the south the Glendon is absent, prob-
ably due to erosion of sediments down to the Ocala limestone, for in
phosphate workings at High Springs and as far south as Dunnellon,
residual boulders of Glendon limestone are found. The limestone
around Brooksville in Hernando County has many features in common
with the Glendon, but the exact stratigraphic relations require more
study before they can be stated with any accuracy.
Economic Uses-The hardened phase of the limestone has led to
its use for railroad ballast and, on a small scale, as a concrete aggregate,
building stone and in the manufacture of quicklime. The softer phase
has not been used but is first-rate material for highway purposes and
also in the manufacture of quicklime and cement.

MIOCENE SERIES
TAMPA FORMATION
The limestone exposed around Tampa was examined by Conradi
as early as 1846. Subsequently many other geologists-Allen,2 Tou-
rney,3 Kerr and Mitchell4 and Heilprin5-all visited the locality and
published accounts of their investigations. Dall published an account
of his studies of this area in 18926 and this, together with his later papers,
give more complete descriptions of the Tampa exposures and show that
there are two beds represented which he designated the Tampa silex

IConrad, T. A.: Observations on Eocene formations and descriptions of 105 new
fossils of that period from the vicinity of Vicksburg, Miss. Proc. Philadelphia Acad.
Sci., vol. 3, pp. 19-27, 1848. Am. Jour. Sci., 2nd ser., vol. 2, pp. 36-48, 1846.
2Allen, J. H.: Am. Jour. Sci., 2nd ser., vol. 2, pp. 36-48, 1846.
"Tuomey, M.: Notice on the Geology of the Florida Keys and the southern coast
of Florida. Am. Jour. Sci., 2nd ser., vol. 11, pp. 390-394, 1851.
4Mitchell, Elisha, and Kerr, W. C., Scientific Soc., p. 87, 1884.
5Heilprin, Angelo: Explorations on West Coast of Florida. Trans. Wagner
Free Inst. Sci., vol. 1, pp. 10-11, 1887.
6Bull. No. 84, U. S. Geol. Survey, pp. 112-113, 1892.

78 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

bed lowermostt) and the Tampa limestone (uppermost). Because
the "silex bed" is characterized by the presence of the gastropod Or-
thaulax pugnax, Dall called this the "Orthaulax bed" and the limestone
above the "Cerithium rock"7 on account of the many specimens of that
genus there present. Matson in 19098 obtained additional information
concerning these rocks; he shows the presence of a limestone belowthe
silex bed and the existence of clay beds at both the top and base of the
formation. The clay at the top of the formation was later, in 1913,9 by
Matson believed to belong to the Alum Bluff group. The limestone
underlying the "silex bed" he thought to be the same as that above
("Cerithium rock"of Dall) and the "silex bed" merely to be a zone of
replacement in this limestone formation. This last account is now
accepted as correct.
Stratigraphic position-Matson10 bases his evidence of an uncon-
formity upon the results of wells drilled in the city of Tampa. In one
well after passing through thirty feet of limestone and chert the drill
encountered forty-one feet of clay, while in a second well, two hundred
feet away, at about the same depth sixty-four feet of the same clay was
drilled through. This variation was interpreted to mean that the under-
lying Ocala limestone has an irregular surface produced doubtless by
erosion.
The present writer saw the contact of the Tampa and the Ocala
limestones in a narrow prospect shaft on the Tournley property about
two and a half miles southwest of Istachatta, Hernando County. The
hard Tampa limestone outcrops at the surface here and rests with seem-
ing unconformity upon the soft pure Ocala at a depth of thirty-nine and
a half feet. The exact relation could not be well observed as the pros-
pect pit was very narrow and consequently the light was very poor at
the bottom and the soft Ocala had only just been encountered. The
post-Oligocene beds present above the Tampa limestone rest upon it
unconformably.
The exact relation of the Tampa to the Glendon is not clear by any
means, the presence of Orthaulax pugnax and certain corals in both for-
mations has led to the assumption that they are, in part at least, contem-
poraneous. The fossils on which this information was based were col-
TOp. cit.
SMatson, G. C., and Clapp, F. G.: Florida Geol. Survey, 2nd Ann. Report, pp.
85-86, 1909.
9Matson, G. C.: U. S. Geol. Survey, Water Supply Paper 319, p. 103, 1913.
10Idem, p. 103.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 79

elected from the Tampa at Ballast Point and nearby places and from the
Glendon (then considered Chattahoochee) in southern Georgia. The
limestones found in other areas and referred to these two formations
have not been studied paleontologically, but were examined during the
course of field work for this report and certain similarities noted. In
the Glendon in Hamilton and Suwannee counties the fossils are predom-
inantly pelecypods preserved as casts and impressions and the echinoid
Cassidulus gouldii (Bouv6), considered restricted to this formation, is
fairly abundant. In the limestone, considered here Tampa, in Hernando
County the general faunal assemblage is strikingly similar, both in man-
ner of preservation and individual character, as far as can be determined
in a cursory field examination; moreover, in the Florida Rock Products
pit just west of Brooksville many specimens of the Cassidulus gouldii
were collected. Further detailed stratigraphic and paleontologic work
is necessary to throw nmore light on this difficult problem and additional
information may result in furthering the theory of contemporaneousness,
with definite boundaries to each formation or else will include all these
similar limestones in one formation with definite faunal zones.
At the present time the limestone around Tampa Bay is typically the
Tampa formation of lowest Miocene age. The rock near Brooksville is
tentatively referred to this formation. The restricted Chattahoochee is
thought to be contemporaneous with the true Tampa.
Lithologic description-In the vicinity of Tampa the rock is usually
a fairly hard, compact but not semicrystalline, light gray to yellow lime-
stone. Fossils preserved as casts and molds which have been left by
the solution of the original shells are abundant in most exposures. The
"silex bed" represents a silicified zone in this limestone and is therefore
a zone of replacement, nodules of chert occur at other horizons through-
out the limestone. The fossils in this "silex bed" are replaced by the
siliceous mineral chalcedony which gives them a beautiful and delicate
coloring as well as faithfully reproducing the minute details of the
original structures. These weathered out of the limestone and were
found lying upon the ground or else imbedded in a soft "rotten" matrix;
Ballast Point was a famous collecting ground in former days, and this
place and the specimens gathered there were carefully studied, but tour-
ists and collectors have long since exhausted the available material and
collections of these famous forms can no longer be made.
The limestone in Hernando County, particularly accessible in quar-

80 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Fig. 15.-Tampa limestone in pit of Florida Rock Products Company,
Brooksville, Hernando County.

ries in the Brooksville area, is referred to the Tampa formation, but
differs in lithology from the type area and shows variations even in
this region. The usual phase is an almost semicrystalline cream to light
gray rock, sometimes with many voids due to casts and molds of fossils,
other times quite dense and homogeneous, but always has an irregular
fracture much like that of fuller's earth; on the fresh face the rock often
has a slight greenish color and inorganic stains, again reminiscent of
fuller's earth. Another phase of the Tampa is a rather soft amorphous
white limestone that shows the same fuller's earth-like fracture; scat-
tered irregularly through this softer material are small masses or lenses
of dense light to dark brown crystalline limestone. In northwestern
Hernando County the Tampa limestone outcrops in hard indurated sur-
face boulders with considerable flint; one artificial exposure in this sec-
tion shows about nine feet of limestone in a fresh face; this material
occurs in irregularly fractured masses of almost completely crystalline
dense fine-grained limestone, light gray to white in color that weathers
into easily crumbled material with a light green to yellow color and the
characteristic fuller's earth-like fracture. In these two last mentioned
phases no fossils in any form were seen.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 81

Paleontologic description-The paleontologic record of the Tampa
formation is almost entirely based on Dall's studies of the "silex bed"
fossils since these forms are beautifully preserved, in marked contrast
to the organic remains in other parts of the limestone. Orthaula.v pug-
nax is characteristic of the "silex bed" of the Tampa limestone and this
horizon has furnished a great number of species of corals, gastropods,
pelecypods and a few Orbitolites floridanus which are quite abundant in
the limestone overlying this bed at Ballast Point. The complete list of
fossils from the "silex bed" was given by Dall," who noted the closeness
of relation to the Oak Grove and Chipola formations as well as the
assembly of land shells present in the formation which is predominantly
marine.
Areal distribution-Limestone of the Tampa formation outcrops at
Ballast Point on the north side of Hillsborough Bay, at Six Mile Creek
east of Tampa, and at intervals along the Hillsborough river in the
north-central portion of Hillsborough to the Pasco County line. In the
east side of Hillsborough Bay, Pleistocene marls mask the limestone and
over the eastern portion of the county unconsolidated sands and clays
of the Alum Bluff overlie it. Limestone referred to this formation out-
crops in small amounts in northern Pinellas County around Sutherland
and Tarpon Springs though covered in many places by a heavy sand
mantle; it also underlies all of Pasco and Hernando counties with the
exception of a narrow strip along the eastern boundaries from Istachatta
to Dade City and Richland. In the northern part of this area the Ocala
limestone outcrops and in the southern part around Dade City and south-
ward the Alum Bluff enters the section. In a small area over most of
extreme southern or southwestern Citrus County, the Tampa limestone
outcrops or lies beneath a sand and soil mantle of variable thickness.
Economic uses-The limestone of the Tampa is most accessible for
economic development in western Pasco and central and northwestern
Hernando counties. In this area the predominant phase is a hard, almost
semicrystalline limestone showing an abrasion test with a per cent of
wear of 6.3% and a French coefficient of the same figure. At present
the material is quarried for railroad ballast, topping material in road
surfacing, concrete aggregate and other uses of hard crushed stone. The
11Dall, W. H.: Tertiary fauna of Florida. Trans. Wagner Free Inst. Sci., vol.
3, pt. 6, pp. 1564-1568, 1893. Also Dall, W. H., A monograph of the molluscan fauna
of the Orthaulax Pugnax zone of the Oligocene of Tampa, Florida. U. S. Nat.
Museum Bull. 90, 1915.

82 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

material does not occur in large enough uniform beds to be used as a
building stone, though some small use is made of the irregular boulders
in foundations, etc., in construction work. This limestone is of a higher
specific gravity and greater density than the usual Florida limestones
and should be of value as a cement ingredient. Though not quite so
chemically pure as the Ocala, these same qualities should make it valuable
in manufacturing building lime, for it would obviate the "fines" pro-
duced by handling the soft Ocala rock in quarries and kilns.
CHATTAHOOCHEE FORMATION
Name-The varying lithology of the limestones, marls and sandy
clays exposed along the Apalachicola river has been very puzzling to
geologists studying this area and, has led to several different groupings
of the formations. The paucity of fossil remains has further added to
the difficulty of the problem.
Langdon' first applied the name Chattahoochee to the beds of im-
pure limestone underlain by thinner beds of purer limestone exposed
along the Apalachicola river between the towns of Chattahoochee,
Ocheesee and River Junction. Foerste2 included these same beds under
the name "Chattahoochee beds proper." In 1892, Dall3 called this for-

Piig. 16.--Exposure or Chattahoochee limestone on A. C. L. R. R. near River
Junction, Gadsden County.
lSome Florida Miocene. Am. Jour. Sci., 3rd ser., vol. 38, pp. 322-324, 1889.
2Am. Jour. Sci., 3rd ser., vol. 48, pp. 41-54, 1894.
3U. S. Geol. Survey Bull. No. 84, p. 87, 1892.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 83

nation "Ocheesee beds," but in a later paper he notes the absence of
exposures at Ocheesee4 and uses the names Chattahoochee formation5
and Chattahoochee limestone.6 Matson and Clapp7 retained the name
Chattahoochee formation and restricted it to "those limestones and marls
of northern and western Florida which lie stratigraphically between the
limestones of the Vicksburg group and the Chipola Marl member of the
Alum Bluff formation." The Chattahoochee has generally been consid-
ered of upper Oligocene age, but now is considered lowest Miocene.
In the present discussion the definition of Matson and Clapp is fol-
lowed in the main; i. e. the name Chattahoochee formation is applied to
those beds of argillaceous limestone and mottled sandy calcareous clays
as are seen exposed at the type section, the new highway. bridge (for-
merly Chattahoochee ferry-landing) over the Apalachicola river one-
half mile west of the town of Chattahoochee in Gadsden County. The
separation of the Ocala limestone from the Marianna and Glendon
(Vicksburg group) in northwest Florida has done much to solve the
problem, for the earlier geologists included what is now known as Glen-
don in the Chattahoochee formation and thus gave it a much larger
areal distribution than it properly has. Also, the actual contact was
never seen, and, since the Glendon is a very pure quite fossiliferous lime-
stone and the Chattahoochee very impure, and sparsely fossiliferous,
their true relation was further clouded.
Areal Distribution-The Chattahoochee, as now defined, has a very
limited distribution of a few miles in extent along the Apalachicola river
in the vicinity of Ocheesee, Rock Bluff, Chattahoochee and perhaps a
short distance north of the latter place. No outcrops are to be seen
much more than a mile or so from the river in an east-west direction; in
all probability the formation has a lenticular outline, which fact coupled
with other evidences of lithology, etc., suggests that the Chattahoochee
might not be a separate formation as many have thought, but represents
a local variation of the Chipola.marl of the Alum Bluff group, or'else is
the stratigraphic equivalent of the Tampa.
Thickness and Lithologic description-The type locality of the
Chattahoochee formation is at the Chattahoochee Landing on the Apa-

4Dall, W. H., and Stanley-Brown, Joseph: Cenozoic geology along the Apalachi-
cola River. Bull. Geol. Soc. America, vol. 5, p. 154, 1894.
5Idem, p. 152.
"Idem, p. 155.
7Fla. Geol. Survey, 2nd Ann. Report, p. 74, 1909.

84 FLORIDA GEOLOGICAL SURVEY-16TII ANNUAL REPORT

lachicola river in Gadsden County. The following generalized section
was taken there:

Red, coarse mottled sandy clay, and some small gravel, upper ten to fifteen
feet at least, terrace m aterial......... ............... ............. 50 feet
Sandy greenish clay somewhat resembling impure fuller's earth; exhibits
jointing and conchoidal exfoliation, in places slightly indurated....... 10 feet
Varying lithology, chiefly argillaceous limestone grading upward into sandy
greenish-gray impure calcareous clay............................ 17 feet
Mottled sandy clay, red-purple to yellow and gray........................ 17 feet
Argillaceous limestone, lower twenty feet is massive light yellow-green,
soft and compact, weathers in sloping banks with "mud-crash" appear-
ance. Upper forty-five feet is harder, more brittle, chalk-white, exhibits
jointing and weathers in vertical banks with some still harder ledges
showing an exfoliated surface.............................. : ....... 65 feet
Alluvium of river bottom composed of reddish sands. No exposures of beds
beneath this alluvium were seen.................................... 15 feet
164 feet

The thickness of the limestone of the Chattahoochee is therefore
sixty-five feet at this location, though the entire formation is one hundred
and eight feet at least and probably a little more if the base could be seen.
The limestone itself is very impure and variable in composition; analyses
show that it carries 14-15 per cent CaCO3; 9-11 per cent MgCOs and
from 69-72 per cent SiO2. Iron and alumina are present, usually about
five per cent. Where the material has been exposed and weathered, as
in the railroad cut at River Junction, the combined carbonates seldom
amount to more than five per cent and the iron and alumina also are
greatly reduced. Silica, as would be expected, is very high (90-95%).
In a fresh face the limestone has a dull greenish-gray color and is quite
"damp" and soft, though very homogeneous and fine even-grained.
Upon weathering it bleaches to a chalky white and becomes hard and
brittle. The limestone is fairly well stratified in hard and soft ledges
and jointed throughout. It fractures in large masses and breaks with
sharply demarked but curved faces. The jointing also shows curved
outlines, and the faces exposed by this rounded fracturing are stained
a deep yellow green-black. Practically no organic remains are seen,
but occasionally a poorly preserved cast or small flaw of hazy outline is
found in the usually smooth uniform rock.
Sections of outcrops of the Chattahoochee show a great variation
and are difficult to correlate; this rapidly changing lithology is believed to

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 85

be due chiefly to the weathering of the underlying impure limestone, in
part perhaps to local changes at the time of deposition.
Economic Uses-At one time this limestone was hailed as the
world's greatest natural cement,1 but it was later found that the deposit
was quite variable and unsuitable for this purpose. Since that time
practically no use has been made of this soft impure rock except as bulk
material in local fills or dam construction.

~i,.

Fig. 16a.-Upper part of Chattahoochee limestone at Victory Bridge (Old
Chattahoochee Landing). Photo by N. B. Davis, 1925.

120th Ann. Report, U. S. Geol. Sur., pt. VI (Cont.), p. 547, 1899.

86 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

ALUM BLUFF GROUP1

The name "Alum Bluff" was first used in 1892 by Dall,2 who applied
it to certain gray sands, in part non-marine, conformably overlying the
Chipola marl at Alum Bluff on the Apalachicola river in Liberty County,
Florida. The sands were considered lower Miocene in age.

Matson and Clapp in 19093 first proposed Alum Bluff as a forma-
tional name; they believed it to be of Oligocene age and defined it as
follows:

"The name Alum Bluff formation as here used includes those beds
which belong stratigraphically between either the Chattahoochee forma-
tion or the Hawthorne formation and the marls and limestones of Mio-
cene age. This usage differs from that of Dall, who appears to have
regarded the Chipola marl and the Alum Bluff as distinct formations.
The Alum Bluff formation includes two different, though closely related,
members which have been known respectively as the Chipola marl and
the Oak Grove sands. To these is added a third member, recently dis-
covered by Vaughan in West Florida, and called the Shoal River marl
member, from the stream where it is best exposed."

In 1915 vertebrate fossils were discovered fifteen miles north of
Tallahassee at a depth of twenty-five to fifty feet below the surface in
gray phosphatic sands of the Alum Bluff formation. E. H. Sellards,4
at that time State Geologist of Florida, studied these remains and on
their evidence reinstated the Alum Bluff in the Miocene. The Alum
Bluff is now considered by Miss Gardner as a group and the three former
members are raised to formational rank.

1The Alum Bluff Group is of the greatest importance to the geologist interested
in the stratigraphy of Florida and presents a problem that for the last thirty years,
at least, has received much attention by leading paleontologists and stratigraphers.
However, it possesses little intrinsic economic value for the purpose of this report
and so the group will be treated in the briefest manner. Miss Julia Gardner of the
United States Geological Survey has spent several seasons in the field on this prob-
lem and has prepared several professional papers covering fully the fauna and
stratigraphy. The writer is indebted to her for the following information.
2Dall, W. H.: Bull. U. S. Geol. Survey No. 87, p. 112, 1892.
3Matson, G. C., and Clapp, F. G.: Florida Geol. Survey, 2nd Annual Report,
p. 67, 1909.
4Sellards, E. H.: Florida Geol. Survey, 8th Annual Report, p. 92, 1916.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 87

CHIPOLA MARL
The type locality of the Chipola marl is on the farm of Mr. John
McClelland, one mile below Bailey's Ferry on the Chipola river, Calhoun
County, Florida; however, the exposure at Alum Bluff was the first to
be studied and it along with an exposure at Rock Bluff received the
most attention by Langdon,5 Dall6 and other workers. The marl has a
large fauna distinct from both the Tampa and Oak Grove and indicates
a warmer climate than the two succeeding formations of the group. Its
thickness is estimated from one hundred and thirty to one hundred and
fifty feet. The Chipola marl includes with its equivalent, limestones, marls,
sands, sandstones and fresh-water deposits and has a very wide distribu-
tion in northern Florida. The fuller's earth beds in Gadsden and Leon
counties are placed in this formation. Marls and some local limestones
along the Choctawhatchee river just above Miller's landing and on
Holmes creek are of Chipola age, as is the limestone at Sopchoppy in
Wakulla County. The stratigraphic relations of the Alum Bluff between
the Ocklocknee and Aucilla rivers are not obvious and the limestone
there has not been definitely placed, but in the northern parts of Leon and
Jefferson counties the red sandy clays are taken as the typical develop-
ment of the Alum Bluff.
Cooke and Vaughan studied the extent of the Alum Bluff in north-
ern peninsular Florida and placed much of the old "Hawthorne beds"
in this group. Cooke7 believed that at White Springs the Alum Bluff
rests on the Glendon (formerly called Chattahoochee) but farther south
overlaps and rests upon the Ocala limestone. The presence of a fuller's
earth bed in Manatee County has served as the evidence that beds of the
Alum Bluff group underlie much of Hillsborough, Polk and Manatee
counties.
OAK GROVE SAND
The first mention of the Oak Grove is by Johnson :8 "The younger
Miocene . is perfectly and largely developed on the bluffs of the
Yellow river, from the Alabama line to Milligan, in Florida, the most
northern of these beds being the low shell landing at Oak Grove, six
miles south of the line." Dall recognized in the Oak Grove fossils, a
fauna distinct from that of the Chipola marl and suggested a correlation

5Langdon, Daniel W., Jr.: Am. Jour. Sci., 3rd ser., vol. 38, p. 322, 1889.
GDall, William Healey: Bull. U. S. Geol. Sur., No. 84, p. 122, 1892.
7Cooke, C. Wythe: Unpublished notes.
8Johnson, Lawrence C.: Science, vol. 21, p. 91, 1893.

88 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

of the Oak Grove with the Rock Bluff.9 No evidence, however, has so
far been offered which has established the presence of the Oak Grove
in Florida east of the Choctawhatchee river.
The Oak Grove at the type locality on the Yellow river in Okaloosa
County is a compact dark bluish gray sand weathering brown
and forming a well-defined platform that stands at ordinary water level
about a foot above the river and extends down into the stream for
eighteen inches or so. Another exposure is at Tanner's grist mill on
Senterfitt creek, two miles northeast of Oak Grove. The marl there is
grayish-blue, weathering brown and abundantly fossiliferous, it outcrops
eighteen inches to two feet above the water's edge. The marl at that
locality according to Vaughan is thirty feet above the Oak Grove expos-
ure and it contains a larger Shoal River element than the Oak Grove,
but the relationship to the Oak Grove is considered closer. The total
thickness of the Oak Grove is a little less than thirty-five feet. Miss
Gardner believes the Oak Grove to be the least significant of any of the
Alum Bluff formations; its fauna contains only a little more than two
hundred species and is intermediate between the Chipola and the Shoal
River.
SHOAL RIVER MARL
In the same report in which he mentions the shell bed at Oak Grove,
Johnson10 makes note of another fossiliferous deposit which seems to
be the locality now known as Shell Bluff on the Shoal River. Vaughan
was the first to recognize the Shoal River as a distinct member of the
Alum Bluff and gives the following section from Shell Bluff :11
8. Gravel-covered slope, gravel elipsoidal, V2 inch probably usual length,
rarely 1 inch, mostly quartz, in rather coarse red sands.............. 30 feet
7. Gray, finer sand, blotched yellow, decidedly argillaceous. ............ 10 feet
6. Greenish shell marl, matrix arenaceous, fine fossiliferous (Shoal River
m arl m em ber) .................................................. 27 inches
5. Non-fossiliferous, coarser greenish sands, becoming argillaceous at base 3 feet
4. G reen clay ....................................................... 6 inches
3. Coarser sands, gray, greenish, last 2% feet loose, purple and white sands 6 feet
2. U exposed ....................................................... 15 feet
1. Non-fossiliferous green sands, oxidized yellowish on surface (Oak
G rove sand m ember) ........................................... 10 feet
Total of section, about............................ .... go80
Miss Gardner states that bed number one, which Vaughan correlates
with the Oak Grove, carries a small but diagnostic Shoal River fauna;
9Dall, W. H.: Bull. Geol. Soc. Am., vol. 5, p. 166, 1893.
10Johnson, Lawrence C.: Science, vol. 21, p. 91, 1893.
"Vaughan, T. Wayland, Florida Geol. Survey, 2nd Annual Report, p. 105, 1909.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 89

it contains a perceptibly larger number of Oak Grove species than the
upper, but is referable to the Shoal River. The upper and lower beds
at Shell Bluff are much the same lithologically except that the upper
bed is more sandy and contains less argillaceous material.
A few outcrops of the Shoal River marl are found near Shell Bluff,
but no others are known to occur in Walton County north of the L. & N.
railroad. South of DeFuniak Springs and south of Argyle marls that
are considered to represent both the upper and lower beds are exposed
in several creeks-Euchee or Bruce creek, Alaqua, Folks, and White's
creek. These outcrops are usually rather thin, about four feet in thick-
ness, and are not exposed for any considerable distances in the creek
bottoms. The marl seems to underlie, at a comparatively shallow depth,
all this section, for wells thirty or forty feet in depth all pass through it.
The thickness of the Shoal River marl is best seen at Shell Bluff,
where about forty feet of marl and sand are exposed; the marl has a
rather limited distribution as it has not been recognized outside of Walton
County. No contact has as yet been seen between this marl and the
overlying Choctawhatchee.
CHOCTAWHATCHEE MARL
Name-In 1892 Dall referred all the Florida beds of true Miocene
age to the Chesapeake group; the subdivisions of this group were the
Jacksonville limestone in east Florida and the "Ecphora bed" in the
western part of the State. He states1 that "at Alum Bluff the group is
represented by what I have termed the Ecphora bed, of gray marl, with
over 100 species of fossils, many of which are common to North Caro-
lina, Virginia and Maryland. It has a thickness here of 30 feet or more."
Later, Dall2 applied the name aluminouss clay" to the 10 to 15 feet of
gray unfossiliferous clay overlying the "Ecphora bed" on the Chipola
river. Matson and Clapp3 in 1909 included both these beds in the Choc-
tawhatchee marl, the name being taken from the Choctawhatchee river,
where, in the vicinity of Red Bay, the formation is well exposed.
Stratigraphic Position and Thickness-At Alum Bluff, according
to Vaughan, the Choctawhatchee rests uncomformably upon the wavy
erosion surface of the sediments of the Alum Bluff group. It is uncon-

1Dall, Wm. H., and Harris, C. D.: Neocene of North America, U. S. Geological
Survey, Bull. 84, pp. 123-124, 1892.
2Dall, Wm. H., and Stanley-Brown, Joseph: Cenozoic Geology Along the Apa-
lachicola River. Bull. 5, Geol. Soc. Amer., pp. 168-169, 1894.
MFlorida Geol. Survey, 2nd Ann. Report, pp. 114, 1909.

90 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

formably overlain in turn by unfossiliferous red and yellow sands of
probably Pliocene and Pleistocene age. The average thickness of the
Choctawhatchee is probably not much over 15 to 25 feet, though in places
it may be over twice that. The following exposed thicknesses were
noted: Jackson's Bluff (Ocklocknee river), 10 feet; Red Bay (Gomillion
property), 19 feet; Darling's Slide (Chipola river), 31 feet; Four Mile
creek, 10 feet, and Econfina creek, 3 miles southeast of Betts, 15 feet.
Miss Julia Gardner gives the formation in the vicinity of Red Bay a
total thickness of at least 90 feet.
Lithologic description-The Choctawhatchee is usually greenish
gray to light gray in color and consists of varying quantities of quartz
sand and shell; in some places the marl contains a little organic matter
and is slightly phosphatic. The shells vary in profusion, at Jackson
Bluff they are quite plentiful, well distributed throughout the marl and
are large and massive; at Four Mile creek they are practically confined
to the lower two feet of the section and here are closely packed; at Dar-
ling's Slide the small rather fragile shell, Mactra congesta, forms 80 per
cent of the fossil shell matter and the more massive and larger forms are
subordinated. The clay bed which at this last locality occupies the
upper eight to twelve feet is light steel gray in color, unfossiliferous and
quite plastic; it is also present at Four Mile creek and at Alum Bluff.
Paleontologic description-The Choctawhatchee marl contains an
abundant fauna of nearly 200 species. The most numerous is Mactra
congesta. Other prominent mollusca are: Ecphora quadricostata, Venus
rileyi, Arca acutilaqueatum, Cardita arata and various species of Cor-
bula, Pecten, Phacoides, Dentalium, Turritella, etc.
Areal Distribution-The Choctawhatchee is found at the surface
in a narrow belt six to twelve miles wide, extending from south of De-
Funiak Springs, Walton County, east and slightly southward into south-
west Leon County to about the Ocklocknee river or a little beyond. The
formation does not exert any particular topographic influence on the
country it underlies on account of its thinness and a heavy mantle of
younger sands and clays, but does form the walls and chief support of
the narrow strip between stream channels in this area. In the Deadens,
Washington County, S. 18, T. 1 W., R. 13 W., it forms the rims of the
shallow sink holes.
Economic Uses-The marl is used locally as a fertilizer or soil-
corrective. Its chief value is the lime content; phosphate is only present
in very small quantities.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 91

PLIOCENE SERIES
CALOOSAHATCHEE MARL
Name-The first account of Pliocene beds in Florida was given in
Heilprin's report of 1887.1 He described the shell marls exposed along
the Caloosahatchee river and gave them the name "Floridian." The
name "Caloosahatchee marl" was applied by Dall to the Pliocene beds
along the Caloosahatchee river and the streams entering Charlotte Har-
bor.2 He described the shell marls in this area and agreed with Heilprin
in referring them to the Pliocene. In subsequent papers3 Dall called
these marls "Caloosahatchee beds" from the type locality on the river of
that name, thus including the "Floridian" of Heilprin. The proximity
and close resemblance of the "Arcadia marl"4 of Dall seems to warrant
regarding it as a phase of the main formation and it has been included
under the name "Caloosahatchee marl" which is retained for the Pliocene
marl beds of the Caloosahatchee river and neighboring streams as de-
scribed by Dall.

Stratigraphic Position and Thickness-The contact of the Caloosa-
hatchee marl with the underlying Miocene has not been seen. Phos-
phatic marls referred to the Alum Bluff group (Miocene) are known to
underlie large areas in the region north of Lake Okeechobee and it may
be that they have been eroded from the land now covered by the Caloosa-
hatchee. The considerable change of the fauna from the Miocene to the
Pliocene would seem to indicate an erosion interval. The Caloosahat-
chee is overlain by variable thicknesses, usually thin, of Pleistocene marls
and sands. This contact is sometimes fairly clear and when so shows
an unconformity; usually it is obscured due to a reworking of the marl
by the advancing Pleistocene sea. The exposed thickness of the Ca-
loosahatchee is seldom over six to eight feet and generally less than this;
a consolidated marl containing Pliocene fossils was encountered at a
depth of nine feet at the St. Lucie lock on Lake Okeechobee and was

IHeilprin, Angelo: Explorations on the West Coast of Florida. Wagner Free
Inst. of Science, Trans., vol. 1, pp. 26-33, 1887.
2Dall, Wm. H.: Notes on the Geology of Florida. Am. Jour. Sci., 3rd series,
vol..34, p. 169, 1887.
3Dall, Wm. H.: The Neocene of North America, U. S. Geol. Survey Bull. No. 84,
pp. 140-149, 1892, and Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, pp. 1603-1605, 1893.
4Dall, Wm. H.: The Neocene of North America, U. S. Geol. Survey Bull. No. 84,
pp. 131-132, 1892.

92 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

Fig. 17.-Typical exposure of Caloosahatchee beds (Pliocene), Caloosahatchee
River, Florida.

dredged to a depth of 18 feet without reaching the base, so that the max-
imum thickness of the formation may be as much as 25-30 feet.

Paleontologic description-The total number of species of shells
from the Caloosahatchee is listed by Dall5 as six hundred and thirty-nine,
of which two hundred and fifty-six are peculiar to this formation and
three hundred and fourteen are known to be Recent. The fauna is typically
that of a shallow tropical sea. Dall recognized the fact that the upper
part of the Caloosahatchee contains forms more closely related to present
ones than does the lower part, and especially the profusion in the upper
beds of Chione cancellata, Planorbis, Physa and other fresh-water or
estuarine species.

Lithologic description-The Caloosahatchee consists of a light gray
shell marl which is often interbedded with nearly pure sand. The matrix
is usually calcareous, made up of fragmental shells, though in places
light-colored sand takes their place; even in a calcareous matrix, sand is
quite abundant. The formation is remarkable for the state of preserva-
tion of the shells as well as for the profusion in which they are found.

5Dall, Win. H.: Tertiary Fauna of Florida, Wag. Free Inst. Sci., Trans, vol. 3,
pt. 6, pp. 1604-1605, 1893.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 93

The Caloosahatchee if subjected to weathering agencies will form a hard,
impure, compact limestone; this has been well shown in digging the St.
Lucie Canal, where the material at a depth of 10-15 feet frequently
necessitated blasting in order for the dredge to handle it.
Areal Distribution-The farthest northward outcrops of the Caloo-
sahatchee are in Pinellas and Hillsborough counties around Old Tampa
and Hillsborough bays. South of there it immediately underlies a large
area consisting of most of Sarasota, DeSoto, Highlands and Glades coun-
ties and a small part of northern Charlotte. In all probability this for-
mation underlies Lake Okeechobee and most of the Everglades. It has
been encountered at a depth of nine feet at the St. Lucie lock on Lake
Okeechobee and probably in other canals on the east side of the lake, but
no fossil determinations have been made from these localities.
Economic Uses-The marl consists chiefly of variable quantities of
Si02 and CaCOs with a small percentage of iron .and alumina. Its
main commercial use is as road material; the consolidated marl phase
has been used to construct the new Conners Highway from Okee-
chobee City to Twenty Mile Bend on the West Palm Beach Canal. The
softer marl is also much used locally for roads.

94 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

NASHUA MARL
Name-The name "Nashua marl" was proposed by G. C. Matson
and F. G. Clapp,' for the beds of Pliocene marl extensively developed
in the valley of the St. Johns river; the beds were believed to. have cer-
tain faunal elements which distinguished them from other Pliocene beds
of Florida. They were designated Nashua marl from a locality on the
St. Johns river in Putnam County.
Stratigraphic Position and Thickness-It was formerly believed
that the Nashua marl might rest unconformably upon the Miocene at
DeLand, but further study of the fossil collections shows the absence of
diagnostic species of Miocene age. Miocene sediments may be present,
but are at a depth and will only be encountered in well borings. White
and brown sands of the Pleistocene unconformably overlie the Nashua
marl. In addition to the undulating erosion surface of the marl, the
abrupt change from the profusely fossiliferous marl to the barren sands
emphasizes the break between the two. The thickness of the Nashua
marl is usually about four to seven feet, though locally it may be thicker.

'~- ~'r
~

Fig. 18.-Digging Nashua marl for road material, DeLeon Springs, Volusia
County.

1Matson, G. C., and Clapp, F. G.: Florida Geol. Survey, 2nd Ann. Report, pp.
128-130, 1909.

A PRELIMINARY REPORT ON THE LIMESTONES AND MARLS OF FLORIDA 95

In some marl pits west of DeLeon Springs it attains a thickness of ten to
eleven feet. Samples from a well drilled at DeLand indicate that the
sand and marl of the formation here may be as much as thirty-two feet
thick.
Lithologic description-Lithologically the Nashua marl bears a
close resemblance to the Caloosahatchee, though it appears to have a
slightly more clayey matrix. The matrix is usually light yellow in color
and made up of sand with a large amount of finely broken shell particles.
Large and massive shells and shell fragments are closely packed but not
consolidated. Toward the southern limits of the formation, around
DeLand and Orange City, the material seems more broken up and inti-
mately mixed with larger amounts of yellow clayey sand. To the north
the large shells predominate and the matrix is composed of a smaller
amount of nearly white-cream colored sand.
Paleontologic description-The fauna of the Nashua marl is very
much like that of the Caloosahatchee but has in addition many forms in
common with the Waccamaw marl of the Carolinas. Since the original
paper by Matson and Clapp, two publications by Mansfield2 have added
immensely to the paleontologic record of this formation.

Arcal Distribution-The Nashua marl is developed, as far as is
known, only in the valley of the St. Johns river and for a short distance
to the southeast. It underlies the following counties: southeastern Put-
nam, southwestern Flagler, northeastern Volusia and the narrow eastern
edge of Marion and Lake. Wherever found the marl is covered by six
to twenty feet of unconsolidated sand. The best exposures are in the
marl pits at DeLeon Springs.
Economic Uses-The marl has been extensively used in Volusia
County for road building and has proven highly satisfactory.

2Mansfield, W. C.: Molluscan fauna from the calcareous marls in the vicinity
of DeLand, Volusia Co., Florida. Fla. Geol. Survey, llth Ann. Report, pp. 111-
123, 1918.
A Contribution to the Late Tertiary and Quaternary Palentology of Northeast-
ern Florida. Fla. Geol. Survey, 15th Ann. Report, pp. 25-51, 1924.

96 FLORIDA GEOLOGICAL SURVEY-16TH ANNUAL REPORT

PLEISTOCENE SERIES
During Pleistocene time about half of the present Florida land mass
was under water. The area submerged includes parts of Escambia,
Santa Rosa, Okaloosa, Walton, Bay, Calhoun, Franklin and Wakulla
counties, in the western portion of the State. In the south the margin
of the Pleistocene sea extended a little north of Hillsborough Bay, pass-
ing thence southward to the southern end of the divide between the
Peace and Kissimmee rivers. It followed the west side of the valley of
the latter stream, and probably the land lying east of the St. Johns river
was also submerged; certainly the valley of this stream and the whole
east coast strip up into Georgia were under water.
In this extensive sea many different types of deposits were laid
down; in the cooler waters to the west and north, lying near the older
northern land masses sands and some impure clays were the principal
deposits, but in the more tropical areas abounding with marine life and
farther removed from the older land masses, limestones and marls pre-
dominated. Some of these deposits are wholly or in part contempora-
neous, while others are clearly older and younger. To accurately differ-
entiate all of them and map their limits is well nigh impossible, for since

Fig. 19.-Marl and calcareous sand, Cape Sable, Monroe County.

	Front Cover
	Front Matter
	Frontispiece
	Title Page
	Letter of transmittal
	Table of Contents
	Administrative report
	Statistics on mineral production...
	A preliminary report on the limestones...
	Index
	Back Matter
	Back Cover
	Back Cover

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