Geology of Jackson County, Florida

STATE OF FLORIDA
STATE BOARD OF CONSERVATION
Ernest Mitts, Director

FLORIDA GEOLOGICAL SURVEY
Herman Gunter, Director

GEOLOGICAL BULLETIN NO. 37

GEOLOGY OF JACKSON COUNTY, FLORIDA

by
WAYNE E. MOORE
Associate Professor
VIRGINIA POLYTECHNIC INSTITUTE

Published for
THE FLORIDA GEOLOGICAL SURVEY
Tallahassee, 1955

/1"

AGRI-
CULTURAL
LIBRARY

Frontispiece
Aturia alabamensis (Morton), lateral view xO.6. Specimen is from the upper
2-3 feet of the Bumpnose member of the Crystal River formation, locality J-5.
(F.G.S. no. 1-7387).
ii

ABSTRACT
This is a report of a detailed study of the geology of Jackson
County, Florida. As a result of limited testing, certain clays ap-
pear to be suitable for the manufacture of common brick, tile, re-
fractory brick, and art pottery. Abundant high calcium limestone
reserves are available, and these, with the Miocene clays, could be
used to manufacture cement. One localized structure may have
produced a trap for petroleum.
The county can be divided into three physiographic units: the
Marianna River Valley Lowlands, the Delta Plain Highlands, and
the Terraced Coastal Lowlands, all minor units of the Coastal Plain
Province. These minor units have been produced by the degrada-
tion and alluviation of streams and by the coastal erosion of the
sea. Although limestone now crops out at the surface, the Marianna
River Valley Lowlands are the result of normal stream erosion of
the plastic sediments that once mantled the area. Three stream
terraces, a high delta plain, and a marine terrace are to be found
in the county.
Six units of Tertiary rocks are shown on the geological map.
The oldest rock cropping out in the county is the Crystal River
formation. Although the Bumpnose limestone, a new stratigraphic
name, was mapped in detail, it is given a member designation since
it is believed to be a facies of the Crystal River formation. The
shallow water fauna of the Crystal River formation grades downdip
into a deeper water fauna that characterizes the Gadsden limestone,
a new formation. The absence of the Marianna limestone at the
surface in eastern Jackson County is caused by a combination of
structure, erosion, and terrace mantle. The Suwannee limestone
thickens rapidly to the south between Dry Creek and Sink Creek.
Erosion of the Suwannee limestone from structural highs before
the deposition of the overlying Tampa formation is responsible for
this thickening.
The Tampa formation in Jackson County consists predominantly
of plastic deposits to the west and north and is essentially calcareous
to the south and east. No deposits that could be assigned to younger
Miocene formations were recognized in the county, but it is possible
that a part of what is considered to be Tampa formation in this
report may be younger than that formation. In particular, beds in
the southwestern part of the county may belong to Miocene forma-
tions younger than the Tampa formation. The age of the highest
sand deposits in the southwestern part of the county is probably
Pliocene ?-Pleistocene.

FLORIDA STATE BOARD

OF

CONSERVATION

LEROY COLLINS
Governor

R. A. GRAY
Secretary of State

J. EDWIN LARSON
Treasurer

NATHAN MAYO
Commissioner of Agriculture

THOMAS D. BAILEY
Superintendent Public Instructhon

CLARENCE M. GAY
Comptroller

RICHARD ERVIN
Attorney General

ERNEST MITTS
Director of Conservation

LETTER OF TRANSMITTAL

Jlorida geological Survey

Callakassee

March 25, 1955

Honorable Ernest Mitts, Director
Florida State Board of Conservation
Tallahassee, Florida

Sir:

This report, being published as Florida Geological Survey Bul-
letin 37, is entitled THE GEOLOGY OF JACKSON COUNTY,
FLORIDA, and it was prepared by Wayne E. Moore, Associate Pro-
fessor of Geology at Virginia Polytechnic Institute while he was
a candidate for the degree of Doctor of Philosophy at Cornell Uni-
versity. This department supervised the field work, and the faculty
at Cornell University supervised the laboratory work and the prepa-
ration of the manuscript.

As originally submitted the manuscript could not be published
and the details of editing were largely unacceptable to the writer.
In order that the locations of the outcrops and the details of the
economic evaluation can be made available to the public, the report
is being published without additional editing although the reader
should keep in mind that the opinions expressed are those of the
writer and do not necessarily reflect those of the personnel of the
Survey.

Moore's interpretation of the "Cypress fault" presented on
pages 26 to 29 of the report and shown on figures 5 and 6 does not
conform to that of the Survey staff nor to that of the geologists of

the several oil companies who have worked the well samples of the
area. The section and discussion are presented as the writer gave
them because he believes that they represent an accurate interpre-
tation. Differences in the interpretation of the stratigraphy, par-
ticularly in the details of the division of the Ocala group of Florida
also exist. It is anticipated that Florida Geological Survey Bulletin
38 will be a comprehensive regional evaluation of the stratigraphy,
paleontology and facies of the Ocala group in Florida.

Respectfully yours,

Herman Cunter, Director

Printed by E. O. Painter Printing Company, DeLand. Florida

FOREWORD

This study of Jackson County was made possible by a coopera-
tive agreement between the Department of Geology, Cornell Uni-
versity, Ithaca, New York, and the Florida Geological Survey,
Tallahassee, Florida. The Department of Geology at Cornell Uni--
versity furnished laboratory facilities; the Florida Geological Sur-
vey provided financial assistance, field equipment, and supervision
of the field work.
The writer was assisted in the field by temporary employees of
the Florida Geological Survey: Mr. T. W. Lins, in the summer of
1947, and Mr. Neil FitzSimmons in the summer of 1948. The late
Mr. Clarence Simpson, Florida Geological Survey, assisted the
writer at intervals during the summer of 1949.
Dr. W. Storrs Cole, Chairman of the Department of Geology,
Cornell University, supervised the research. Dr. C. M. Nevin and
Dr. J. W. Wells of that department gave freely of their time for
discussion and criticism throughout the study. Dr. Herman Gunter,
Director, and Dr. Robert 0. Vernon, Assistant Director, of the
Florida Geological Survey supervised the field work.
The writer wishes to thank the faculty of Cbrnell University and
his colleagues at the Virginia Polytechnic Institute who willingly
gave much time to discussing the problems encountered in this work.
The writer wishes to thank Mr. J. T. Hurst, 1945-49 Supervisor,
and Mr. George Vathis, 1950-54 Supervisor of the State of Florida
Department of Conservation, and Dr. Herman Gunter, Director,
Florida Geological Survey, for their financial aid. Dr. Gunter, Dr.
Vernon, and Dr. J. L. Calver of the Florida Geological Survey ac-
companied the author in the field on several occasions. Dr. Vernon
frequently discussed with the author the problems of stratigraphy
and Pliocene-Pleistocene terrace surfaces in this area.
The author wishes to express his appreciation for the financial
assistance granted him under the Shell Oil Fellowship in Geology
during the academic year 1949-1950.
The late Professor Emeritus G. D. Harris, and Dr. K. V. W.
Palmer of the Paleontological Research Institute examined the
palecypods and gastropods from the Lepidocyclina (Nephrolepi-
dina) chaperi zone. Dr. C. Wythe Cooke, United States Geological
Survey, studied the echinoids collected from the L. (N) chaperi
zone.
The citizens of Jackson County, through their interest and as-
sistance, contributed much to the successful completion of the study.
The water well drillers of Jackson County deserve special thanks

for their assistance in collecting samples from wells. Those who
contributed samples were:

E. J. Carlisle Henry Prestwood
A. C. Clark Gray Artesian Well Co.
B. F. Johnson E. P. Perkins
F. M. Green H. E. Baker

The Coastal Petroleum Finding Company of Houston, Texas,
through Mr. A. D. Aden, supplied many elevations of road corners
and other landmarks, so that the altimeter elevations in this report
are more accurate than would otherwise have been possible.
Mr. Harold Jean Steffan prepared most of the base map for the
geological map, utilizing the Jackson County road map of the Flor-
ida State Road Department as a guide.
Dr. W. D. Lowry, Dr. R. V. Dietrich, and Dr. Mary H. Ross of
Virginia Polytechnic Institute, criticized the manuscript.
The Engineering and Industrial Experiment Station, University
of Florida, Gainesville, Florida, performed the clay tests included
in this report.

CONTENTS

ABSTRACT .. . . . . . . . ..------- ------ .----- iii

LETTER OF TRANSMITTAL .. .............. ...--- --- v

FOREWORD vii

INTRODUCTION ------------- 1
Location --------------- ---- 1
General economy ----------------- 2
Facilities 2-------------------

FIELD METHODS ----------- 3
Location of points -------------- 3
Determination of elevations ------- ------- 4
Maps ------ -------- -- ------------------------------- 4

PREVIOUS GEOLOGICAL WORK IN JACKSON COUNTY -.._-- 4

GEOMORPHOLOGY ------------- 6
General ------------------- 6
Marianna River Valley Lowlands ---------- 7
Delta Plain Highlands -8-. --- ----- ------ 8
Terraced Coastal Lowlands __ --- ----____ __- 9
Development of terraces --------------------------------- 9
Relationship of stream terraces to streams -------- 13
Stream course changes -----------------------. -----....- .- 13
Jointing reflected in stream courses ---- ------- 15
Karst topographic features ----------- 16
Steepheads ...-- ----------------__-- 17

STRATIGRAPHY, PALEONTOLOGY, AND STRUCTURE -----. 18
Introduction -- .-- ..-----...-- ----.. ---- -------_..._.___... -- 18
Eocene Series ... .---------------. -------... . . . . ..-----------.. --- 20
General _--- ----- ---------- 20
Moodys Branch formation and equivalents ----- -- 22
Cypress fault --- .----- -- -- -- __ __- 26
Ocala group -- ------- 29
H history .--- ---------------------.............. -------- 29
Crystal River formation ------------------------... ..--.. .. 30
Historical ------. .--------. -------------------.---------- 30
D definition ..----------- -- -- -------------.... .. ... . .... ....__ __.. 31
Lithology --- _._------.--. -......- ----------------... 31
Thickness and structure ----------- 32
Paleontology ------32
Local details ------------ ----- 32
Bumpnose member of the Crystal River formation --..------ 36
Historical .... - -----------... .. .... 36
Definition -----.... ......------ _. .__....... .._.___ . .._ ....._... ._ 40
Lithology ---.-- ........ ......-- ----- ---. .- ... -... ......... .__... 40
Thickness ------------------... ------ ----- -.._.. ..... 40
Paleontology .---------------- --- ------- -------...... .. .---_ 40
Local details --- ------------... -__ -----.___ -- __--. .... .. . 41

Gadsden limestone ------------- 42
Historical -..------------ ---------------- 4........ . 42
Definition .--.- ----- -- 43
Lithology --... .. .___....... -- 44
Thickness and structure -. --------- --- 44
Paleontology ------------------ -- 44
Local details -..... ---------------------------... --.... _- 44

Oligocene Series ....-------- -- -- - --- 44
Marianna limestone -------------- 44
Historical ...-------------- 44
Definition .----- --------- -----... ..--------.- ----- 44
Lithology .....--- --- ----- -----------.....-----.--... --------- 45
Thickness and structure --------- 45
Paleontology ---------------- 45
Local details -- 45

Vicksburg group and Chickasawhay marl ---- 51
Suwannee limestone -------------51
Historical -.. --------.--_ .. ---- 51
Definition ... ------------- ----- 51
Thickness and structure -- ----------- 51
Paleontology ........---- ---------.. ------- ..- 53
Local details ------------------ 55

Miocene Series ....-------- -----. ----------.-- --..- -.......-- .----- 58
Tampa formation ..... ------------------.-.-..--.----- 58
Historical -- --------- ------------------------ 58
Definition --------- -------- 58
Lithology --------- -- ---- 58
Thickness and structure ...--------- 58
Paleontology --. ----------- -------------- 59
Local details ------------ ------ 59

Post-Miocene deposits _. ------. -----------69
Historical ......--------- ------ 69
General discussion --------- -------- 69
Lithology and thickness ------------ 71
Residual boulders -- 71

SEDIMENTATION, BIOFACIES, AND STRUCTURE .---. 71
Biofacies evidence __..-_.---.-......-.------------------ 73
General --- ... ------------.... ---.....- 77
Crystal River formation -------..------------------ 79
Bumpnose member --.---------------- 80
Marianna limestone --------------80
Suwannee limestone ....... -----------------------------------.- 80
Miocene (Tampa) --------....------------- .--- -------- -.- 81
Post-Miocene .--.---------.-- ----......------- 82
Summary -.. -- --. --... .. ...-----.--. .--------.. ... 82

ECONOMIC GEOLOGY ------.-.....--............. .----.-.. .. --------.. -... 82
General ----- .-.- ..---- .- --.-- -... ..------- ---------------.... 82
C lay -- ... -. . . . ---- ---------------. 82

Exploration for clay ...------------ ----.- 84
Sand and gravel --.---------. -----------------..--- 84
Limestone -...--....-.....-------.---------------...... 84
Ground water ...-- ------- -- ---- 885
Petroleum ---- --.-........------- -- ---..-- 87

SELECTED BIBLIOGRAPHY -- ---..-----... -------....----- -- 90

APPENDIX I .....--- ------..-------... .---- --- ......... -97

APPENDIX II --....- ---...... ---- ........ .. -100

LIST OF ILLUSTRATIONS
Page
Frontispiece. Aturia alabamensis (Morton) --.. ------ ii
Figure
1. Location map showing Jackson County -------- 1
2. Angular stream pattern of Chipola River, probably caused by
jointing .-...---------.----...-..... 15
3. Locality J-141. A steephead just north of Alliance --- 17
4. Geologic formations in Jackson County, Florida ----- 19
5. Structure map of the Claiborne Eocene ------ 27
6. Structure map of the Ocala group ...----------- 28
7. Locality J-5, Marianna Limestone Products, Company. Rock
being quarried is Lepidocyclina (Nephrolepidina) chaperi zone,
the Bumpnose member, and Crystal River formation ------ 37
8. Locality J-12. The uppermost bed is the Lepidocyclina (Nephro-
lepidina) chaperi zone. The lower rock is more typical of the
Crystal River formation _-- ..... ------- 39
9. Structure map of the Marianna limestone ---- ------.. 46
10. Suwannee limestone at locality J-78 is overlain by "bentonitic"
clays and terrace deposits. The dark halo surrounding the
white rock is the "bentonitic" clay. The Marianna limestone at
this locality is not shown in this picture ------------- 47
11. Locality J-14. Marianna limestone at Chipola River bridge
east of Marianna on highway U. S. 90 -------------.---...._.... 48
12. Locality J-13. Marianna limestone overlain by Suwannee lime-
stone ---..-- ..----- ------..--------------- ---- 50
13. One of a series of gentle arches in the Tampa formation just
south of Jackson County in Calhoun County on the Chipola
River. North is to the right in the picture ------------- 52
14. Dip of Suwannee limestone at Sink Creek bridge on the Chipola
River ------------....-------- -- ...... 52
15. Map, top of Oligocene sediments .--..--------.... .---------......... 54
16. Map, probable thickness Tampa formation ----- ---- 60

17. Structure map of Tampa formation --- ------- 61
18. Upper part of Tampa formation as exposed at east end of Jim
Woodruff Dam on Apalachicola River, just north of Chattahoo-
chee. in Decatur County, Georgia ---------- 62
19. Composite section of the Tampa formation at east end of Jim
Woodruff Dam. Elevations at 0 feet, 40 feet, and above 122 feet
are accurate. Elevations shown to the left were determined by
levelling ... --- -----_. ---- ---- --63
20. Locality J-195. Tampa formation clays overlain by "bog iron"
and terrace deposits on highway Fla. 276 east of the Florida
Industrial School for Boys -------. 67
21. Locality J-87. Railroad cut at Round Lake showing Miocene?
clays (Alum Bluff?) overlain by terrace deposits --. --- 70
22. Drainage canal south of Malone cut in terrace deposits. Looking
west from highway Fla. 71 ..-----.-- 72
23. Residual boulders of Suwannee limestone in terrace deposits
forming the sides of the drainage canal south of Malone ----..... 72
24. Camparison of foraminiferal faunas of the Bumpnose limestone
and Gadsden limestone. "Large" Foraminifera omitted .------._- 75
25. Isopach map of the upper Eocene, Oligocene, and lower Miocene
formations --- 78
26. Community House, Marianna, Florida. This building is con-
structed of Marianna limestone .-- _-.- 86
27. The residence of Mr. Cecil Rhyne, Marianna, Florida. This
house is constructed of Marianna limestone blocks faced with
ferruginous sandstone -- ---------------- 86

PLATES
Plate
I Geologic Map ---.--------- --- In pocket
II Terrace Surfaces Map _---------- In pocket
III Structure Section A-A' ----- -----In pocket
IV Structure Section B-B' ----- -.---------- In pocket
V Structure Section C-C' ------------- In pocket

TABLES
Table

1. Some Eocene Foraminiferal zones in Jackson County -21
2. Typical Ocala group foraminiferal faunas ----- 33, 34
3. Suwannee limestone foraminiferal check list 55

Appendix I Formational tops in wells ------------ 97

Appendix II Clay sample test data ...--.--- -.------------.---.-.- 100

GEOLOGY OF JACKSON COUNTY, FLORIDA
by
Wayne E. Moore

INTRODUCTION
Location.-Jackson County is located in northwest Florida and
includes an area of approximately 942 square miles which is
bounded by the State of Alabama on the north, the Chattahoochee
and Apalachicola rivers on the east, Calhoun and Bay counties on
the south, and by Holmes and Washington counties on the west
(Figure 1). The ground surface of the county lies from 100 to 320
feet above sea level except immediately along the rivers where
elevations are lower. The City of Marianna is the county seat.

Figure 1.-Location map showing Jackson County.

FLORIDA GEOLOGICAL SURVEY

The county lies within the Coastal Plain Province, and topo-
graphically may be subdivided into the Delta Plain Highlands, the
River Valley Lowlands, and the Terraced Coastal Lowlands. The
rocks that crop out in the county range from upper Eocene to
Pliocene?-Pleistocene in age. (Plate I). Jackson County is struc-
turally high in a regional sense.

General Economy.-Jackson County is one of the principal agri-
cultural counties in Florida. Field crops, other than vegetables,
fruits, and nuts, are the most important source of farm income with
livestock and livestock products second in importance [Bur. of the
Census, 1951, Jackson Co., (59-032) Series AC50-1]. Listed below
are major agricultural items produced [Bur. of the Census, 1951,
Jackson Co., Fla. (59-032) Series AC50-11:

Item Production
1944-45 1949-50
Value of Farm Products sold $ 4,421,935 $ 5,940,158
Field Crops, other than vegetables, nuts
and fruits $2,953,816 $3,539,051
Livestock and livestock products sold $1,066,822 $1,808,713
Forest products sold $ 45,189 $ 101,544
Cattle and calves, number 26,326 20,493
Whole milk sold, gallons 277,986 778,650
Hogs and pigs, number 54,934 49,013
Chickens, number on hand 119,484 87,229
Corn, bushels harvested for grain 631,869 503,636
Peanuts harvested for picking or
threshing, pounds 32,473,281 26,828,092
Lupine seed harvested, pounds 1,864,200
Irish potatoes harvested, bushels 7,436 5,467
Sweet potatoes harvested, bushels 87,340 46,733
Cotton, bales 2,745 3,603
Tobacco, pounds 105,085 141,488
Sugar cane or sorghum sirup, gal. 124,443
Vegetables harvested, for sale $216,253 $130,005
Pecans harvested, pounds 226,307
Tung nuts harvested, pounds 3,258,418

Facilities.-The 1950 Census of Population Series PC-8 No. 9
and No. 9A gives the following population figures for Jackson
County:
1940 1950
Jackson County 34,428 34,645
Alford 283 375
Campbellton 311 307
Cottondale 719 747
Cypress 212 262
Graceville 1,181 1,638
Malone 442 521
Marianna 5,079 5,845
Sneads 727 1,074

GEOLOGY OF JACKSON COUNTY, FLORIDA

The number of farms with electricity increased from 723 in
1945 to 2,134 in 1950, and during this time the average size of
the farms increased from 97.5 acres in 1945 to 123 acres in 1950.
Transportation facilities in the county are adequate. The Louis-
ville and Nashville Railroad crosses the county in an east-west
direction passing through Cottondale, Marianna, and Sneads. The
Atlanta and St. Andrews Bay Railroad crosses the county from
north to south, passing through Campbellton, Cottondale, Alford,
Round Lake, and Compass Lake. The Marianna and Blountstown
Railroad extends southward from Marianna to Blountstown which
is in Calhoun County to the south.
A number of intercity bus lines serve the area and some 50
buses make stops in Marianna each day. A number of intercity
trucking firms serve the area, and the cities of Atlanta, Birming-
ham, Jacksonville, Mobile, New Orleans, Pensacola, and Savannah,
may be reached by overnight truck haul from Marianna.
The Marianna Airport, which is municipally owned, has 36,000
square feet of hangar space, four 5,000 foot runways, and is
equipped with marker lights for night operation. The field is open
to private planes and charter service is available. Commercial
transportation is provided by the National Airlines which operates
one flight daily each way on the Jacksonville-Pensacola route. A
crop dusting service is maintained at the airport.
Adequate water supplies are available in the county, and mu-
nicipal systems are generally large enough for further expansion.
A modern county-owned general hospital is located in Marianna and
has a 100 bed capacity. A state owned tuberculosis rehabilitation
center with a 200 bed capacity is located near Marianna.

FIELD METHODS

Location of Points.-Since the area included in Jackson County
is large, automobile transportation was used extensively to visit
all portions of the county. This means of transportation was supple-
mented by the use of a boat on the major streams, where necessary.
The map locations of collecting localities were determined either
by plotting automobile odometer distances or by locating the sites
on an aerial photograph mosaic of the county by inspection. All
localities along the Chipola River were determined by very careful
reference to aerial photographs.

FLORIDA GEOLOGICAL SURVEY

Determination of Elevations.-Elevations used in this report
were determined for the most part by means of corrected aneroid
altimeter surveys. The elevations of some wells listed in Appendix
I, however, were determined by instrument leveling done by Mr.
Hal Chittum, the late Clarence Simpson, and Mr. George Benedict
of the Florida Geological Survey. The bench mark control for the
altimeter survey utilized United States Coast and Geodetic Survey
and United States Geological Survey bench marks in areas where
they were available. The Coastal Petroleum Finding Company of
Houston, Texas kindly supplied a large number of elevations along
highways and graded roads which they had determined by stadia
methods.
Frequent altimeter readings through each field day at known
elevations and at field stations permitted the construction of a cor-
rection curve for the readings. The altimeter used in the field was
graduated in ten foot intervals and estimations were made to the
nearest two feet. Elevations determined by altimeter were com-
pared with established elevations a number of times. Discrepancies
of more than ten feet were rare. In critical areas repeated altimeter
determinations of elevations made on different days indicated an
accuracy sufficient to show consistently the gentle dip of the beds.
Maps.-The only map readily available for use in the field was
the Florida State Road Department Highway Map of Jackson
County, which was supplemented by the U. S. Department of Agri-
culture aerial photograph mosaic of the county. The Geological
Map of Florida by C. Wythe Cooke (1945) was valuable in evaluat-
ing the relationship of the county to the entire state and the geo-
logic maps of Holmes and Washington counties (Vernon 1942)
were helpful in determining the relationship of the geology of
Jackson County to these bordering counties. The U. S. Engineer,
Apalachicola River System, Topographic Survey maps were useful
in determining features along and near the rivers.

PREVIOUS GEOLOGICAL WORK IN JACKSON COUNTY

Smith (1881) appears to have been the first to report on the
formations in the county and to describe specific localities of lime-
stone in the vicinity of Marianna, south of Campbellton, at Green-
wood, and at Blue Springs. He prepared a geological map of Florida
which included the Jackson County area. Langdon (1889) described
the rocks exposed at the old Chattahoochee Landing and assigned
the name "Chattahoochee group" to them. Dall and Harris (1892,

GEOLOGY OF JACKSON COUNTY, FLORIDA

p. 107) stated that the limestone exposed along the Chipola River
was not the "Orbitoides" as supposed by Smith.

The first systematic work on the geology of Florida was that
of Matson and Clapp (1909). This preliminary report marked the
beginning of a continuing series of publications by the Florida
Geological Survey which has extended to the present time. Matson
and Clapp (1909) did field work in Jackson County and named the
Marianna limestone from the exposures of the "chimney rock" in
the vicinity of Marianna.

During the next few years work in Jackson County was of
minor nature and consisted of reports on clays, a description of
Ocheesee Lake (Sellards, 1910, p. 67), some data on the artesian
water of the county (Sellards, 1912, pp. 119-122), a report on the
geography and vegetation (Harper, 1914, pp. 193-200), and an
analysis of a brick clay (Sellards, 1915, pp. 17-18).

Cooke (1915, p. 109) described a section on the Chipola River
at Marianna and proved that the Marianna limestone was above
the Ocala limestone. In the same report the upper Eocene age of the
Ocala limestone was established. Cooke (1917) discussed the strati-
graphic range of some larger Foraminifera which he had collected
at Marianna and elsewhere, and in the same paper Cushman (1917)
described some of these larger Foraminifera. In 1920 Cushman
described additional species of these fossils from the Marianna lo-
cality. Sellards (1919, p. 128) showed on a sketch map the struc-
tural high which exists in the Marianna-Chipley area, and this was
expanded in 1922 into a report on the petroleum possibilities in
Florida (Sellards and Gunter, 1922, p. 70; p. 108). Bell (1924,
p. 111; pp. 172-173) discussed some of the clays that 'occur in
Jackson County, and Mossom (1925, pp. 145-151) described the
limestones. In 1926 Mossom (pp. 191-208) reviewed and refined
the structure and stratigraphy of the Marianna-Chipley area.
Cooke (1929) published a new report on the geology of Florida in
which many new outcrops in Jackson County were reported.

Cole and Ponton (1930) described the Foraminifera from the
Marianna limestone, and later Cole (1938) studied the stratigraphy
and micropaleontology of the Granberry well in Jackson County.
MacNeil (1944) did work in Jackson County as part of a study of
the Oligocene stratigraphy of the southeastern United States. He
was the first to question the uppermost Ocala age of the zone charac-
terized by the Foraminifera Lepidocyclina '(Nephrolepidina) cha-

FLORIDA GEOLOGICAL SURVEY

peri Lemoine and R. Douville [L. (N.) fragilis Cushman of Mac-
Neil (1944) and others.]
Periodically from 1915 to the present, Cooke visited Jackson
County in connection with his work on the Cenozoic stratigraphy
of the southeastern United States. Cooke (1945) in the latest edi-
tion of the "Geology of Florida," published by the Florida Geological
Survey, again summarized the geology of Jackson County.

GEOMORPHOLOGY

General.-The entire state of Florida lies within the Coastal
Plain province (Fenneman, 1938). Three predominant topographic
levels make it possible to subdivide Jackson County into three minor
units, the River Valley Lowlands, the Delta Plain Highlands, and
the Terraced Coastal Lowlands (Plate II).
Cooke (1939, p. 4; 1945, p. 8) proposed a terminology for the
geomorphic units in Florida. Vernon (1942, p. 5) proposed two new
terms, the River Valley Province and the Coastal Plains Province,
to replace respectively Cooke's terms, the Marianna Lowlands and
the Western Highlands. Vernon proposed this change with a view
toward making the terms descriptive of the origin of the geo-
morphic units.
Vernon's 1942 terms are undesirable in that they are classed
as provinces, a general term used by Fenneman (1938) in classify-
ing the major geomorphic features of the United States. As any
land forms that may be developed in Florida are minor features
within Fenneman's larger unit, the Coastal Plain Province, it seems
advisable to eliminate the word province from any geomorphic
term which may be applied to units in Florida.
Vernon (1951) proposed a new terminology for geomorphic
units in Florida that eliminates these objections. Consultation with
R. O. Vernon and the staff of the Florida Geological Survey re-
sulted in agreement on these points regarding the origin of geo-
morphic units in Florida:
1. Land forms have resulted in part from the erosion of a plain
of aggradation which was built up during a time of relatively higher
sea level than that which exists today. Remnants of this plain of aggra-
dation are present today in western and central Florida. This plain,
called the Delta Plain Highland by Vernon (1951, p. 16), is underlain
by deposits that have been referred to the Citronelle formation by Cooke
(1945). The development of the constructional plain was terminated in
the Pliocene or early Pleistocene, and since that time sea level has
become progressively lower.

GEOLOGY OF JACKSON COUNTY, FLORIDA

2. Two principal degradational processes have operated since early
Pleistocene to produce the geomorphic units observed today in Florida:
a. Dissection and alluviation by present river systems.
b. Coastal erosion and deposition by the sea.
3. Coastal terraces and stream terraces have developed as a result
of a number of periods of relatively stable sea levels, each stable sea
level occurring at a lower level relative to the land than the preceding
one.
The development of these stream and marine terraces will be
discussed later in this report.
The terminology used here for the geomorphic units is that pro-
posed by Vernon (1951, p. 16). These terms refer to the origin of
the unit, and they provide a means of applying a localizing term
where desired. The Delta Plain Highlands refers to the extensive
remnants of a plain of aggradation which include the highest land
areas in Florida. The Terraced Coastal Lowlands include those
areas where marine terraces are distinctive features of the land
surface. The River Valley Lowlands are the terraced lowlands de-
veloped by erosion and deposition of streams. Vernon's term, the
Tertiary Highlands (1951, p. 16), is not used in Jackson County
because this unit is not represented.

Marianna River Valley Lowlands.-The Marianna River Valley
Lowlands is the largest physiographic unit in Jackson County. This
terraced lowland has resulted from erosion and deposition by a num-
ber of streams, namely the Chattahoochee-Apalachicola rivers, the
Chipola River, Dry Creek, and Holmes Creek. The lowlands along
each of these streams, developed as floodplains and terraces, are
considered as one physiographic unit that was developed in the
Marianna area by a complicated sequence of stream erosion, de-
position, and capture. Elsewhere in the state the lowlands along
streams can be specifically related to the stream now occupying the
valley in which the lowlands are developed. This terraced lowland
extends westward into Holmes and Washington counties where the
Choctawhatchee River and Holmes Creek are responsible for its
development. Although this area is underlain by limestone, solu-
tion is not primarily responsible for the development of the low-
lands. Solution is at present modifying the lowlands, but exposure
of the limestones at the surface, by the removal of overlying plastic
sediments, is so recent that no appreciable lowering of the surface
can be attributed to solution. It is a lowland produced by the dis-
section of the Miocene formations. This erosion was accelerated by
the lowering of sea level during the maxima of continental glacia-
tion.

FLORIDA GEOLOGICAL SURVEY

Most of the sediments deposited in Jackson County from Tampa
time until early Pleistocene time, when active downcutting began,
were increasingly plastic in nature. When a reasonable restoration
of these sediments is made from the dip of the Miocene and post-
Miocene beds in Jackson County, it is apparent that a considerable
thickness of plastic sediments has been removed from the area
occupied by the Marianna River Valley Lowlands.
As a result of this erosion the normal cuestaform topography of
a coastal plain rather than karst topography has been formed.
The configuration of the Marianna River Valley Lowlands is con-
trolled by the location of major surface streams (Plate II).
The Flint River and the Apalachicola River occupy approxi-
mately the position of a subsequent stream when the structure of
the area is considered. The prominent escarpment at Chattahoochee,
which extends northeastward into Georgia along the south side of
the Flint River system is the infacing escarpment that marks the
east boundary of the Marianna River Valley Lowlands.
Erosion by Dry Creek, a subsequent stream in the southwestern
part of Jackson County, has produced a north-facing escarpment
that limits the Marianna River Valley Lowlands to the south.
In the southeastern part of Jackson County the small streams
which are tributary to the Chipola River and which extend east
and northeast from Sink Creek have produced a north-facing es-
carpment which forms the other boundary of the Marianna River
Valley Lowlands. The Marianna River Valley Lowlands extend
westward from Jackson County into northern Washington County
and into Holmes County, but there the lowlands can be specifically
identified with the Choctawhatchee River and Holmes Creek, and
may be called properly the Choctawhatchee River Valley lowlands
(Vernon, 1951, p. 16). With the exception of the westernmost part
of the county where the lowland is related to Holmes Creek, the
lowland in Jackson County is associated with streams of the Apa-
lachicola River system.
Delta Plain Highlands.-The Delta Plain Highlands include
that part of Jackson County south of Dry Creek and north of
Compass Lake extending eastward to about the center of R. 10 W.
This area is characterized by elevations generally above 240 feet.
Elevations as high as 320 feet were measured in sections 25 and 26,
T. 3 N., R. 12 W. between Compass Lake and Round Lake. Cooke's
topographic division, the Western Highlands, and possibly the Cen-
tral Highlands, are remnants of this surface.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Terraced Coastal Lowlands.-The Terraced Coastal Lowlands
in Jackson County lie south of the Delta Plain Highland, and in the
southwestern part of the county extend southward from Compass
Lake. An extensive high flat area that is present east of the Chipola
River southward and eastward from Alliance probably belongs in
the Terraced Coastal Lowlands, but it may have been developed
by streams.
Development of Terraces.-Three stream terraces, one marine
terrace, and an older dissected highland are found in Jackson
County in addition to the present flood plains (Plate II). As prev-
iously pointed out by Vernon (1942, 1951), each marine terrace
has fluviatile equivalents in each major stream valley in Florida.
In Jackson County these stream terraces lie at intervals above the
present flood plain of 30-50 feet (Pamlico), 60-100 feet (Wicomico),
and 145-165 feet (Okefenokee). Vernon (1951, p. 40) uses the
names assigned to the marine terraces by Cooke (1945) as modi-
fied by MacNeil (1950) to apply to the stream terraces as well.
This simplifies the terminology required to discuss these terraces,
and Vernon's practice will be followed here.
The stream terraces in Jackson County have slopes approxi-
mately the same as those of the flood plains of the present streams
which occupy the valleys where the terraces are found. The highest
fluviatile terrace, the Okefenokee, may not have a slope parallel to
the present flood plains, as its slope has not been determined ac-
curately.
The marine terrace, the Coharie, has a maximum elevation in
Jackson County of 240 feet north of Compass Lake, and it slopes
seaward to a minimum elevation of about 170 feet south of Jackson
County (Vernon, 1942, p. 17). Above the marine terrace is an older
dissected highland which has a maximum elevation of 320 feet
and which generally lies above 270 feet.
Similar terraces have been observed in coastal plain areas in
many parts of the world. The widespread occurrence of these ter-
races, separated everywhere by approximately the same intervals,
has caused them to be cited as examples of evidence of changes in
sea level. In recent years the origin of these terraces has been at-
tributed by Antevs (1928, 1929), Daly (1925, 1929), Fisk (1938,
1939, 1940), Russell (1940), Vernon (1942, 1942a, 1947, 1951),
Cooke (1945), and others, to sea level fluctuations during the Pleis-
tocene when large quantities of water were removed from the sea
and locked temporarily in the continental glaciers. In this theory

FLORIDA GEOLOGICAL SURVEY

it is proposed that, while sea level was falling and rising as the
glaciers advanced and retreated, the land gradually stood higher
relative to the present sea level in the areas where these terraces
are preserved. In this way when sea level reached a new maximum
height during glacial minima, it would not reach its former level
on the land and the terraces formed during the previous maxima of
sea level would be preserved. Attempts have been made to cor-
relate these terraces with the various glacial advances.
In Jackson County the three major stream terrace levels are
related in general to the present streams of the area. Between each
of these major levels there are minor terraces, especially between
the two highest terraces.
Above the stream terraces there is present, in the extreme
southern part of the county, a marine terrace, the Coharie, with a
maximum elevation of about 240 feet. This terrace can be traced
in Jackson County (with the exception of the Chipola River Valley)
from the vicinity of Compass Lake eastward to the Sneads area
where remnants of it are preserved as summits of high, flat-topped
hills. The high, flat plain around and immediately south of Alliance,
in the south central part of Jackson County, represents the best
development of the Coharie terrace. The Coharie terrace extends
from Jackson County eastward into Gadsden County and west-
ward into Washington County.
The stream terraces are progressively younger from highest
to the lowest. This is confirmed when the degree of dissection of
the terraces is considered, for the higher surfaces are most dis-
sected and the lower surfaces are least dissected. The higher sur-
faces are frequently represented only by the flattened summits of
isolated hills, and the deposits show evidence of greater weathering,
especially oxidation of iron, as compared to lower surfaces. Lower
surfaces also tend to retain more of the flood plain features than
do the higher terraces.
This arrangement of the terraces, with the oldest at high ele-
vations and the youngest at low elevations, suggests one of three
possibilities: 1, the land has risen intermittently relative to sea
level; 2, the sea level has fallen eustatically in stages; or 3, the land
has risen uniformly as sea level dropped and rose eustatically to
its former level several times. Locally, it is frequently impossible to
separate the effects of the first two possibilities for the end results
may be the same. Sea level changes, however, produce world wide
effects which indicate changes of the same amount taking place in

GEOLOGY OF JACKSON COUNTY, FLORIDA

the same direction at the same time. Vertical movements of the
land are apt to be local, to occur at different times, and to be in
different directions in various places. The third possibility has
been used by Fisk (1938) to explain stream terraces in Louisiana.
According to the theory of stream terrace development outlined by
Fisk (1938, p. 67-72; 1940, p. 57) and extended to Florida by Ver-
non (1942, p. 26), each of the terrace levels represents a period of
valley cutting followed by drowning and alluvial filling of the river
valley. The periods of valley cutting occurred during glacial per-
iods when sea level was lowered, and the period of drowning and
alluvial filling coincided with the warm interglacial periods when
the glaciers retreated.

A period of valley cutting followed by a period of valley alluvia-
tion compose a cycle, and the surface of the alluvial fill would cor-
respond in elevation with the previous flood plain unless uplift of
the landmass occurred during the cycle or unless sea level was pro-
gressively eustatically lowered, in which case the new alluvial fill
would be below the previous flood plain by the amount of relative
uplift which occurred during the cycle.

In Louisiana, Fisk (1938, p. 69; 1939, p. 199) and Russell (1940,
p. 1225) demonstrated tilting based upon the steeper slopes of the
older terraces as compared to the younger terraces. This theory
seems to apply most logically to the origin of stream and delta plain
terraces in Louisiana.
In Jackson County, however, no tilt between the Pamlico and
Wicomico stream terraces could be detected though hundreds of
controlled altimeter elevations were taken. These lower terraces
have a slope that is essentially that of the present flood plain of
the Apalachicola River, the Chipola River, and Holmes Creek. The
slope of the Okefenokee surface is not clearly evident as that surface
is well dissected.
The number of terraces observed in the field do not necessarily
mean that there were a corresponding number of major inter-
glacial periods. It is generally agreed, for example, that the climate
has not become as warm since the last major glaciation as was
normal during previous interglacial times or during the period im-
mediately pre-Pleistocene. Sea level will rise if the ice that is at
present located on the continents melts.
Sellards (1916, p. 109; 1918, pp. 86-87) and Vernon (1942, pp. 7,
19-21; 1942a, pp. 302-311; 1947, pp. 97-99) have given evidence

FLORIDA GEOLOGICAL SURVEY

in Florida that sea level is rising, or has very recently risen, based
upon drowned streams both along the coast and inland where tribu-
taries to major streams have been unable to fill their valleys with
alluvium as fast as the major stream.

Estimates for the further rise in sea level that may be expected,
if the climate continues to moderate and all continental ice caps
melt, range from 66 to 165 feet (Flint, 1947, p. 431). If sea level
should rise slowly to 50 feet above its present level, alluviation
would cover the Pamlico terrace, provided the streams could re-
establish or maintain approximately their present gradiants. Simi-
larly, a sea level rise of 100 feet would alluviate the Wicomico ter-
race. Where attempts to correlate marine or stream terraces with
interglacial periods are made, the expected further rise of sea level
and the probable sea level stands during any interglacial periods
proposed should be considered.

Daly's estimate that sea level was lowered some 250 feet below
present sea level at the height of glaciation seems to be of the right
order of magnitude. Shepard (1948, pp. 244-245), however, has
proposed that sea level may have been lowered more than this,
based upon a more extensive glaciation than is generally accepted
and upon an accumulation of glacial ice to greater thicknesses than
generally proposed. Dr. von Engeln (1950, pp. 161-163) proposed
that subcrustal density changes may have operated to raise the land
masses uniformly. It appears certain, therefore, that a sea level
change did occur; that the lowering of sea level amounted to at least
250 feet during the times of maximum glaciation.

Cooke (1945, pp. 245-248) has suggested that a progressive
lowering of sea level permitted the terraces to be preserved, and
that this resulted from periodic increases in the capacity of the
ocean basins caused by lowering of a large segment of the ocean
floor. Such an eustatic lowering of sea level would have world wide
effects, and the theory does not require any uplift of the land to
preserve the terraces formed during maximum sea level stands
during glacial minima.

Uplift has occurred in Florida, or sea level has been eustatically
lowered, since the deposition of the Delta Plain Highlands. This
uplift probably occurred in late Pliocene or early Pleistocene time.
Fisk's general theory of terrace development, sea level fluctuations
coupled with uplift of the land or eustatic lowering of sea level,
seems to explain best the development of these terraces.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Relationship of Stream Terraces to Streams.-The relationship
of the lower stream terraces, the Pamlico and Wicomico surfaces,
to the present streams within the county is rather clear (Plate II).
These terraces generally parallel the existing major streams in
the county, Holmes Creek, the Chipola River, and the Chattahoochee-
Apalachicola River. The deposits underlying these surfaces are
generally from 30 to 50 feet thick, and they are underlain by Ter-
tiary sediments. Locally, Tertiary sediments may come to the
surface of the terraces as silicified pinnacles, and in some areas the
terrace flats and the surface of the Tertiary deposits apparently
are at the same elevation.

The relationship of the Okefenokee surface to existing streams
is not so obvious. In the western part of Jackson County, for ex-
ample, this surface appears to be level in a north-south direction,
but it is generally so dissected that its slope cannot be determined
with certainty.

Stream Course Changes.-The interconnection between the Ma-
rianna River Valley Lowlands and the Choctawhatchee River Valley
Lowlands to the west, and the apparently anomalous slope of the
Okefenokee terrace suggest that a stream pattern different from
that in existence today may have been present in the past. The
existence of what appear to be unusually deep valley fills supports
the idea that major stream courses have been altered, probably by
capture, during the Pleistocene.

Near the road corner in the NW1/4 sec. 22, T. 6 N., R. 10 W.,
there is a buried channel, or one of many large sinks associated
with an old subterranean stream, that is closely associated with a
high hill which seems to be a remnant of a surface possibly as
high as the Wicomico surface. According to various water well
drillers and the reports of residents concerning the depth of their
wells to bedrock, this buried channel extends north-northeast into
Alabama, a general direction that will join the valley of the Chat-
tahoochee River in the vicinity of Gordon, Alabama. A well drilled
at the road corner mentioned above, indicates that the floor of the
channel was buried to a depth of more than 220 feet below the
present surface, which has an elevation of approximately 130 feet.
A linear topographically low area, not connected with present sur-
face drainage, exists west-northwest of Malone in the center of
the N1/2 sec. 34, T. 7 N., R. 10 W. and it can be seen on the aerial
photograph mosaic, part 3, photograph 11A-39. This topographic

FLORIDA GEOLOGICAL SURVEY

low may be caused by compaction of the sediments filling the buried
channel.
West of the Chipola River, near the top of an abrupt hill which
crosses Highway Fla. 75 in the N.W.1/4 sec. 5, T. 5 N., R. 11 W., wells
were reported which were drilled to depths of nearly 200 feet with-
out encountering bedrock.
The relationships of the stream terraces and the presence of
an assumed stream channel suggest that at some time in the past
a sizeable stream existed where today no stream flows. This sup-
posed stream may have initiated the dissection of the Marianna
River Valley Lowlands. Its buried channel, as inferred from records
obtained from water well drillers, extends northward toward the
present Chattahoochee River. Therefore, it is possible that the
Chattahoochee River once occupied the channel and flowed south-
west across Jackson County.
As pointed out previously, the Apalachicola River and the Flint
River are subsequent streams developed at the base of the north-
west-facing Miocene escarpment at Chattahoochee in Gadsden
County. In this area the presence of the lower stream terraces on
the west side of the river and their absence on the east side of the
river indicate that the Apalachicola River and the Flint River
have been shifting their channels laterally in a southeasterly direc-
tion within relatively recent geologic time.

A submarine valley, the DeSoto Canyon, lies off the Appalachi-
cola delta in the Gulf of Mexico (Shepard, 1948, pp. 213-214, also
fig. 65, p. 179). The depth of this canyon is of the same order of
magnitude as the depth of the buried channel in Jackson County,
if it is assumed that the Jackson County channel was cut from the
surface of the Delta Plain Highland, which has an elevation of 320
feet where it is preserved in the southern part of the county. It
cannot be proved that the buried channel and the submarine valley
are related, because sufficient data are not available at present.
Nevertheless, the magnitude of these valleys suggests the possi-
bility of interconnection.

Shepard (1948, p. 215) notes that the closed depressions in the
bottom of the DeSoto canyon are not typical of most submarine
canyons. A projection of the probable structure of the Oligocene
and Miocene limestone beds, based upon data from the Jackson
County area and the Port St. Joe test well studied by Cole (1938,
pp. 8-16) indicates that Miocene limestone may be present at the

GEOLOGY OF JACKSON COUNTY, FLORIDA

submarine ground surface and that these depressions may be solu-
tion holes developed in Miocene limestone.
Jointing Reflected in Stream Courses.-In certain areas of
Jackson County the stream courses exhibit a rectangular pattern
which can be observed on the aerial photograph mosaic. This pat-
tern suggests a control by fracturing, and may be observed along
the Chipola River and Dry Creek in the area where they join (Fig.
2). In that area both streams are flowing on bedrock of Suwannee
limestone. Southward from this area the regional dip increases and
structural evidence in Jackson County indicates a post-Suwannee-
pre-Tampa flexure or fault may have produced the jointing. In
Calhoun County to the south there is evidence that this structural
movement continued into early Miocene time as indicated by several
small folds in the Tampa formation. The Jackson County portion
of this structure, which is interpreted as a fault, is shown on Struc-
ture Section A-A' (Plate III).

Figure 2.-Angular stream pattern of Chipola River, probably caused
by jointing.

FLORIDA GEOLOGICAL SURVEY

The rectangular stream patterns around the junction of the
Chipola River and Dry Creek are believed to be developed along
tensional fractures and the small folds in northern Calhoun County
are compressional folds developed during the early Miocene. A
mantle of soil and terrace sediments prevented direct observation
of these joints, but structural-stratigraphic evidence and the stream
patterns indicate that the fractures are present.
West of Cottondale a number of creeks exhibit a rectangular
stream pattern, as shown on part 5, photograph TU-13A-63, De-
partment of Agriculture aerial photographic mosaic, and the geo-
logic map, Plate I, in sec. 29, T. 5 N., R. 12 W. Unlike the Chipola
River-Dry Creek area, these creeks flow on alluvium, which is from
30-100 feet thick. Examination of the area failed to reveal any ap-
parent reason for the generally rectangular pattern, but since the
patterns are comparable to those on the Chipola River, it is probable
that fractures in the bedrock extend through the mantle. In south-
ern Jackson County, joints, often clay filled, have been developed
in the sediments of the higher terraces. The average strike of these
joints in southwestern Jackson County and southeastern Washing-
ton County agrees generally with the trends of the rectangular pat-
terns formed by the creeks west of Cottondale. The course of these
creeks may be controlled to a considerable extent by jointing which
has developed in terrace deposits. The joints in the terrace sedi-
ments may have been formed by adjustments of the terrace sedi-
ments to fractures in the underlying Tertiary bedrock.
Karst Topographic Features.-Sinkholes and caves, resulting
from solution of limestone, are developed widely in Jackson County,
and are forming today. Their distribution and their relationship to
the terrace topography indicates that ground water saturation of
the limestone, now and in the past, has controlled their formation
to a considerable extent. Most of the caves are located in the out-
crop area of the Marianna limestone, which frequently forms the
roof rock of the cave. Many caves are formed in the Bumpnose
limestone member of the Crystal River limestone.
Although solution is actively lowering the land surface in
Jackson County, the Marianna River Valley Lowlands do not owe
their elevations to solution processes. As already noted, structural
stratigraphic, and terrace surface relationships indicate that these
lowlands resulted from the development of normal cuestaform
topography by stream erosion. Only during the relatively recent
geologic past has solution assumed a dominant role in lowering the
land surface.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Steepheads.-As indicated by Sellards (1918, p. 27) and Ver-
non (1942, p. 29), these features develop as the result of a combi-
nation of these factors:
1. The development of an escarpment that is:
a. Capped by thick deposits of unconsolidated, permeable sand,
and,
b. Underlain by thick, soft, impermeable clays.
2. Abundant rainfall in the area.
3. Obsequent streams which extend up the face of the escarpment.
The steepheads develop from sapping by springs, which emerge
at the contact of the overlying permeable sand and the underlying
impermeable clay. The water which falls as rain seeps downward
through the permeable sand until it reaches the impermeable clay.
As downward movement is checked by the clay, the water begins to
move laterally, emerging at the surface as springs or seeps which
flow down the face of the escarpment in an obsequent direction. At
the site of a spring the moving water tends to remove some of the
sand and clay, thus undermining the overlying sand which slumps
downward leaving a steep headward termination of the stream.
A steephead developed in the above manner near Alliance in Jack-
son County is illustrated in figure 3. This steephead is actively
eroding headward, and recently has cut across the road.

4

Figure 3.-Locality J-141. A steephead just north of Alliance.

FLORIDA GEOLOGICAL SURVEY

STRATIGRAPHY, PALEONTOLOGY, AND STRUCTURE

Introduction.-The bedrock that crops out in Jackson County
ranges in age from upper Eocene to lower Miocene (Plate I). It is
possible that in the southwestern part of the county deposits of
middle Miocene age are present, but no fossils were found to in-
dicate an age for these deposits, which are not noticeably different
lithologically from deposits of lower Miocene age. The oldest forma-
tion that crops out is the Crystal River formation of Upper Eocene
age, and the youngest is the Tampa formation, of lower Miocene
age. The gravel, sand, and clay deposits underlying the terrace
surfaces represent deposition during the interval between the
Miocene and the Recent. As no fossils were found in these beds,
they are considered to represent the Pliocene-Pleistocene interval.
Figure 4 shows the formations found in Jackson County.

Cole (1938, pp. 19-36) reported in detail the stratigraphy and
paleontology of the older formations underlying the county, based
on the samples from the oil test well, Granberry No. 1. The various
formations penetrated in this well are:

Tertiary formations Depths in feet
Ocala limestone 0-220
Claiborne group 220-723
Wilcox group 723-1726
Salt Mountain limestone 1406-1600
Nanafalia formation 1600-1726
Midway group 1726-1937

Upper Cretaceous formations
Selma formation 1937-2879
Eutaw formation 2879-3454
Tuscaloosa formation 3454-5022

The water well drillers of Jackson County collected many well
samples for the Florida Geological Survey during the course of this
study to aid the interpretation of the subsurface stratigraphy and
structure, but no attempt has been made in this study to determine
the stratigraphy and structure below the Lepidocyclina (Poly-
lepidina) antillea zone of Claiborne age. Most of the water well
samples used in this study were cable tool samples. These wells
will be referred to by the Florida Geological Survey well file num-
ber, and all samples are on file at the Florida Geological Survey.
Appendix I contains logs of the wells referred to in this report.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Figure 4

Geologic Formations in Jackson County, Florida

ER PERIOD EPOCH FORMATION

RECENT

PLEISTOCENE

>-

z

I--
4

a

4
I-

>-

l--

I--

River floodplain alluvium

Marine and fluvial terrace deposits
Pamlico formation

Wicomico formation

Okefenokee formation

Cohorie formation

Possibly sediments of the
Delta Plain Highlands

Tampa formation. Beds of Alum
Bluff age may be present in
southwest Jackson County

OLIGOCENE Suwannee limestone
Marianna limestone

-~ 4

UPPER

Bumpnose Is.mbr.
S- Gadsden Is.
(subsurface
Ocala Crystal only)
Group River
formation

MIDDLE Beds of Cook Mountain age
MIDDLE(subsurface only)
(subsurface only)

PLIOCENE

MIOCENE

L 'J

FLORIDA GEOLOGICAL SURVEY

EOCENE SERIES'
General.-A number of deep wells were completed late in the
preparation of this report which permitted a study of the relation-
ships between the middle and upper Eocene formations in Jackson
County.

Vernon's report on the geology of Citrus and Levy counties
(1952) raised the question of the possible existence of beds of
Moodys Branch age in Jackson County. Further, Puri (1953)
proposed a new classification for the rocks of Jackson age in
Florida by defining the formations within the Ocala group and by
naming formations to subdivide the "Ocala limestone."

No attempt was made to study the middle Eocene for this re-
port, other than to determine the faunal zones that appear in its
upper part so that the nature of the Jackson-Claiborne boundary
in Jackson County could be determined.
Seven Eocene zones are recognized in Jackson County,
and they are shown on the structure sections (Plates III, IV, V).
These zones are based upon the first appearance of the species in
well samples (Table 1).
The Eocene zones in Table 1 require little discussion except
to point out that the Camerina guayabalensis-Lepidocyclina (Plio-
lepidina) ariana zone has been mistaken frequently for the Moodys
Branch formation and in other cases Lepidocyclina (Pliolepidina)
ariana has been misidentified as Lepidocyclina (Polylepidina) an-
tillea (=L. (P.) gardnerae). The zones listed above are Claiborne
in age rather than Jackson because of the presence of Operculi-
noides sabinensis, a species not found in the Jackson stage. Gravell
and Hanna (1940, pp. 412-416) proposed the names Camerina
barker, Camerina mississippiensis, and Lepidocyclina (Lepido-
cyclina) clairbornensis for the species characterizing this zone.
Cole (1944, p. 26) pointed out that Lepidocyclina (L.) claibornensis
was a synonym of L. (Pliolepidina) ariana, and that (Cole 1944,
pp. 39-40) Camerina mississippiensis was a synonym of Camerina
guayabalensis. Cole's practice is followed here. In Jackson County,
Camerina guayabalensis and Camerina barkeri appear to occur to-
gether. Camerina barkeri is dominant in the upper part and Cam-
erina guayabalensis is dominant in the lower part of the middle
Eocene zone.

'Please refer to the Letter of Transmittal.

TABLE 1
SOME EOCENE FORAMINIFERAL ZONES IN JACKSON COUNTY__

SNorthwestern Jackson County Southeastern Jackson County
a 0
rn West of the Cypress Fault East of the Cypress Fault

Crystal Bumpnose member, Lepidocyclina (Nephrolepidina) Gadsden limestone 0
chaperi zone, 0-15 feet. Uvigerina zone, o
b River
o lower member, 0-180 feet.
0
9 formation Operculinoides ocalanus-Asterocyclina
' U zone, 140-160 feet.
40
Operculinoides jacksonensis zone, 30-40 feet

-_-------------- Unconformity ------------------------

a Lisbon Operculinoides sabinensis zone, 10-20 feet

Formation Camerina guayabalensis-L. (Pliolepidina) ariana
b W zone, 50-60 feet

-V L. (Polylepidina) antillea zone, total thickness not determined but at
E E least 40-60 feet.

o Middle Eocene not studied stratigraphically lower.
o

__ ___________________________________________i-

FLORIDA GEOLOGICAL SURVEY

Cole (1944, p. 34) listed the species Lepidocyclina (Pliolepidina)
ariana, Camerina guayabalensis, and Operculinoides jennyi as oc-
curring above the Lepidocyclina (Polylepidina) antillea zone in well
W-336, Nassau County, Florida. Cole (1944, pp. 45-47) expressed
the opinion that 0. jennyi might be a synonym of 0. sabinensis.
These two Operculinoides species are closely related, appear to oc-
cur at the same horizon, and are probably synonyms as suggested
by Cole. Specimens of this type are herein referred to the species
0. sabinensis. In Well W-336, Cole found 205 feet of beds be-
tween the base of the Jackson Eocene and the top of the Lepidocy-
clina (Pliolepidina) ariana zone. These beds, characterized by
Coskinolina floridana, Dictyoconus americanus, and other species,
were not found in Jackson County. The absence of these beds in
Jackson County indicates an unconformity at the top of the Clai-
borne in Jackson County.

The Operculinoides sabinensis zone is distinctive and is the most
useful marker for the top of the middle Eocene in Jackson County.

MOODYS BRANCH FORMATION AND EQUIVALENTS
The presence or absence of beds of Moodys Branch age in Jack-
son County has been a subject of debate. Certain of the Jackson
County well logs on file at the Florida Geological Survey have re-
ferred portions of the Eocene to the Moodys Branch. The beds in
Jackson County generally referred to the Moodys Branch have been
the calcareous, glauconitic sands that underlie the limestones of
the "Ocala limestone." These beds definitely are not of Jackson age
and must be assigned to the middle Eocene. These sandy glauconitic
beds carry Lepidocyclina (Pliolepidina) ariana, Camerina guaya-
balensis, Operculinoides jennyi, and Camerina barkeri, all of which
are middle Eocene fossils and which elsewhere in Florida lie below
the Coskinolina floridana-Dictyoconus americanus zone of accepted
middle Eocene age. It is true that these sandy, glauconitic beds are
lithologically similar to beds of accepted Moodys Branchlage farther
to the west in Alabama. Faunally the beds are not to be correlated,
although the faunal elements are generically similar because of
the similar environments of deposition which are indicated by com-
parable lithologies.

Beds of Moodys Branch age, if present in Jackson County, must
be found in the limestones that have long been referred to the "Ocala
limestone" and which are here referred to the Ocala group (Puri,
1953, p. 34). Puri lists the following faunal zones for the Williston

GEOLOGY OF JACKSON COUNTY, FLORIDA

formation and the Inglis formation in Florida (Moodys Branch
equivalents in peninsular Florida) :

Williston formation
Nummulites moodybranchensis faunizone
Operculina mariannensis-Nummulites jacksonensis faunizone
Inglis formation
Periarchus lyelli floridanus faunizone

In Jackson County no specimens were found that could be referred
to Operculinoides moodysbranchensis (=Nummulites moodys-
branchensis; see Cole 1952, p. 10 for synonymy). Operculina mari-
annensis occurs near the top of the Crystal River formation in
Jackson County, below the Bumpnose limestone member, and has
been identified at a number of lower horizons in the Crystal River.
It remains one of the better markers for the top of the Crystal
River formation in Jackson County. The uppermost beds of the
lower member of the Crystal River ("Ocala limestone") at the
river bridge just east of Marianna, Jackson County, is the locality
from which 0. mariannensis was originally described. Operculi-
noides jacksonensis (=Nummulites jacksonensis, see Cole 1952,
p. 9 for synonmy) does occur in Jackson County in the lower part
of the Ocala group. If Moodys Branch equivalents exist in Jackson
County, they must be represented by the beds containing 0. jack-
sonensis. The O. jacksonensis zone may not be equivalent to the
Moodys Branch formation, however, because:

1. The species of the Moodys Branch formation are not confined
to the 0. jacksonensis zone in Jackson County and some of the
species range as high as the Bumpnose limestone member of the
Crystal River limestone.
2. There is no lithologic reason to separate the zone from the
Crystal River limestone.
3. Faunal indications that the Jackson County area was struc-
turally high during Jackson Eocene and the existence of an un-
conformity at the top of the middle Eocene, suggest that the Jackson
County area may not have been covered by the sea during Moodys
Branch time.

Vernon (1952, pp. 158-159) lists the following Foraminifera
as the most abundant and prominent of the "Ocala (Restricted)"
fauna: Lepidocyclina ocalana, Camerina jacksonensis, C. vander-
stoki, C. moodysbranchensis, Operculinoides vaughani, 0. willcoxii,
and Heterostegina ocalana. Of these species, Puri (1953, p. 34)

FLORIDA GEOLOGICAL SURVEY

cites C. moodybranchensis and C. jacksonensis as zone markers
for the Moodys Branch equivalents. Vernon (1952, p. 111) corre-
lated the Inglis formation with the Applins' (1944, p. 1683) lower
member of the Ocala limestone. The Applins (1944, p. 1684) state,
"In west Florida where the Ocala is chiefly cream-colored chalk, it
is not possible at present to recognize the two members seen in
the peninsular area." Vernon's check list of Foraminifera in the
Moodys Branch formation (1952, table 10) lists Amphistegina pin-
arensis cosdeni as occurring in the Inglis and the Williston forma-
tions, Moodys Branch equivalents. Applin and Applin (1944, p.
1685) state, in referring to the fauna of the lower and upper
member of the Ocala,

Amphistegina pinnarensis Cushman and Bermudez var. lawsoni n.
var. ... is common in the lower member and may be called its key fossil
on the peninsular, but where present in north and west Florida and
Georgia, it apparently mingles with typical species of the upper member
and has there no zonal significance.
Further, Applin and Jordan (1945, p. 130) state,

The lower member of the Ocala is clearly defined in nearly all well
sections studied from the peninsular area of Florida, but could not be
distinguished from the upper member in northern Florida and southern
Georgia, where lower and upper species seem to mingle in a relatively
thin Ocala section.
Gravell and Hanna (1935, p. 330) list the following species as
occurring in the Moodys Branch:
Camerina jacksonensis
C. moodysbranchensis
Operculina vaughani
Lepidocyclina (Lepidocyclina) mortoni (=-L. (L) montgomeriensis)
Discocyclina flintensis
Discocyclina 2 spp.
As indicated above, Camerina jacksonensis and C. moodysbranch-
ensis are not restricted to the Williston formation or to the "lower
Ocala." Lepidocyclina (Lepidocyclina) montgomeriensis occurs
throughout the Ocala group in Jackson County. Cole (1952, p. 4,
locality 140) lists Pseudophragmina (Proporocyclina) flintensis
(-Discocyclina flintensis) and Operculinoides vaughani (=Oper-
culina vaughani) as occurring in the L. (N.) chaperi zone in the
Panama Canal Zone, so that these species can be considered only as
Jackson Eocene markers. Therefore, in Jackson County those
species that have been cited as being characteristic of the Moodys
Branch formation do not have zonal significance for determining
whether beds there should or should not be correlated with the
Moodys Branch. These species do indicate a Jackson age, however.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Faunally, it does not seem wise to attempt to correlate any part
of the Ocala group in Jackson county with the Moodys Branch
formation, with the Inglis formation, or with the Williston forma-
tion. Lithologically, the Ocala group in Jackson County is not
similar to the typical Moodys Branch formation, since it consists
of white to cream colored limestone. No lithologic differences were
noted that would justify the adoption of existing names for Moodys
Branch equivalents or the proposal of new names for such units in
the Jackson County area. The Moodys Branch is believed to be
absent in Jackson County. If it is represented, the Operculinoides
jacksonensis zone is its probable equivalent. The 0. jacksonensis
zone in Jackson County is correlated in this report with the lower
part of the Crystal River formation of Puri (1953). Lithologically
there appears to be no basis for establishing a new stratigraphic
term in Jackson County for the 0. jacksonensis zone, and the beds
should be included in the Crystal River limestone in Jackson County.
The probable absence of Moodys Branch rocks in Jackson County
is not surprising when the stratigraphic sequence is carefully
studied. Beds equivalent to the late middle Eocene Tallahassee
limestone and Avon Park limestone of peninsular Florida are absent
in Jackson County. Wells in Jackson County pass from beds of
upper Eocene age into beds of early middle Eocene (Cook Moun-
tain) age bearing Operculinoides sabinensis, Camerina guayabalen-
sis, and Lepidocyclina (Polylepidina) antillea. The seas evidently
withdrew from the Jackson County area sometime after early
middle Eocene time and prior to late Eocene time. Beds of late
middle Eocene age and Moodys Branch age are therefore absent by
nondeposition or by erosion. The sandy, glauconitic Moodys Branch
formation represents a transgressive lithofacies, and it is my opin-
ion that the Jackson County area was not covered by the sea until
after Moodys Branch time, and that the Operculinoides jacksonensis
zone of the Ocala group represents the initial phase of Crystal
River deposition in Jackson County.
Evidence for a structurally positive position of Jackson County
during late Eocene time, a necessary condition if it is to be the
last area covered by the transgressive Jackson sea, is presented
in more detail later in this report (see p. 71). In Jackson County
the restriction of the Bumpnose limestone (uppermost Jackson
Eocene age) to structurally positive areas, and the occurrence of
equivalent shallow water and deep water biofacies of Crystal River
age indicate that the Jackson County area was structurally positive
during late Eocene time.

FLORIDA GEOLOGICAL SURVEY

CYPRESS FAULT2

A fault that had not been recognized previously was discovered
when the well samples from Jackson County were studied. This
fault is named the Cypress fault because it passes near the town
of Cypress in Jackson County.
The Eocene faunal zones used in this report maintain a rela-
tively constant thickness in Jackson County. A marked disconti-
nuity was observed in three wells, however. Some 40 to 50 feet of
the Ocala group is missing in wells W-1356 and W-1358. The top
of the Ocala group appears at a lower elevation than expected in
well W-1364, and, though a 100 foot interval of sample is missing
at the Ocala-Claiborne group contact, the interval between the top
of the Ocala group and samples of Claiborne age is less than the
normal thickness of the Ocala group. This indicates that either the
lower part of the Ocala group or the top part of the Claiborne group
is missing in well W-1364. These wells lie along a line striking
northeast. Wells to the northwest and to the southeast of this
line appear to have a normal thickness of the Ocala group.
Wells southeast of the above line have thicker sections of the
Suwannee limestone and the Tampa formation than wells northwest
of the line. The displacement necessary to account for the ob-
served thicknesses can be seen on sections A-A' and B-B' (Plates
III and IV). No evidence for thinning caused by an unconformity
could be detected.
A normal fault dipping steeply to the southeast explains best
the thin Ocala group sections along the fault and the thick Suwannee
limestone and Tampa formation sections southeast of the fault.
The Cypress fault is of post-Suwannee-pre-Tampa age. There is
some indication that movement may have continued into early Mio-
cene time while the Tampa formation was being deposited. The
Tampa formation is gently folded in Calhoun County south of
Jackson County in the zone where the steeper dips, caused by drag
near the fault, are returning to the more gentle regional dip (figure
13).
The structure maps of the top of the Ocala group and the Clai-
borne, (figures 5 and 6) and the structure sections A-A' and B-B'
(Plates III and IV) show the details of the fault as they are known.
The dip of the fault cannot be determined with certainty, but it must

2Please refer to the Letter of Transmittal

STRUCTURE MAP

OF THE

CLAIBORNE EOCENE
All doae fr wel itudl i
Contw datum meon 1U 1vel
--.IS. CONTOUR DOTTED WHERE UNCERTAIN
O WELL SAMPLE
X SURFACE OUTCROP
___ PROBABLE PRE TAMPA POST SUWANNEE FAULT

SCALE

w n a w I R 5 W I R 4 W WU

Figure 5.-Structure map of the Claiborne Eocene.

a 14 R I w iw r

"

. . . I D

STRUCTURE MAP
OF THE
OCALA GROUP
Contour dam m.on i.e I.vl
-.6O- CONTOUR OOTTEO WHERE UNCERTAIN
IUAA r LIMIT OF OUTCROP
0 WELL SAMPLE
x SURFACE OUTCROP
PROBABLE PRE TAMPA POST SUNWANEE FAULT

SCALE
4 0 4 ----1254

R 14 w I R is I R .i I R I

S I r t I I r I R 7 I I R W I 4 I

Figure 6.-Structure map of the Ocala group

GEOLOGY OF JACKSON COUNTY, FLORIDA

dip steeply to the southeast. It is reported that the oil test well
W-2777, drilled to the east of the fault, did not encounter the fault,
but it was located almost a mile east of the fault and was drilled to
a depth of only 4113 feet. If the dip of the fault is as much as 45
degrees, well W-2777 would not have encountered the fault at the
total depth reached.
The throw of the fault varies along the strike as shown on the
Ocala group structure map (figure 6). The throw is greater south-
west of the nose shown on the structure map than it is to the north-
east of the nose.
The downthrown block of the fault southeast of the fault trace
seems to have acted as a structurally negative unit prior to the last
recognizable movement. A distinctly deeper water biofacies of the
Ocala group exists southeast of the fault than that found to the
northwest. Further, the Tallahassee and the Avon Park limestones
of middle Eocene age are missing in Jackson County, but they are
present in Gadsden County to the southeast.
The thicker Oligocene section southeast of the Cypress fault
resulted from nondeposition or erosion of the Suwannee limestone
on the upthrown block to the northwest of the fault during faulting
and prior to deposition of the Tampa formation. The slightly
thicker section of Tampa formation on the downthrown block is
further indication that movement associated with the faulting con-
tinued into Tampa time.
OCALA GROUP
History.-The literature pertaining to the "Ocala limestone" is
extensive, has been adequately reviewed in previous publications,
and need not be repeated here. Excellent summaries are contained
in Florida Geological Survey Bulletins 21 and 29. Applin and Applin
(1944 pp. 1683-1685) divided the "Ocala limestone" into an upper
and a lower member, but stated that "In west Florida where the
Ocala is chiefly cream-colored chalk, it is not possible at present to
recognize the two members seen in the peninsular area." Vernon
(1951, p. 111) subdivided the "Ocala limestone" into the "Ocala
limestone (restricted)" and the Moodys Branch formation, the
latter of which he divided into the Williston and Inglis members.
Puri (1953, p. 34), in a paper presented before the Society of Eco-
nomic Paleontologists and Mineralogists used the term Ocala group
and divided the Ocala group into three formations: the Crystal
River formation, the Williston formation, and Inglis formation.
The Williston and Inglis formations are Vernon's members of

FLORIDA GEOLOGICAL SURVEY

the Moodys Branch formation raised to formational rank. The
Crystal River formation for the most part is equivalent to the
"upper Ocala" of Applin and Applin.
Beds younger than the Crystal River of Puri occur in Jackson
County at the top of the Ocala Group. These beds are here named
the Bumpnose limestone member of the Crystal River limestone
for the exposures along and near the Bumpnose road north and
west of Marianna, Florida. Further, there is present in the sub-
surface of southeastern Jackson County a series of beds of Crystal
River age that thicken to the southeast and are characterized by
a deeper water foraminferal fauna. The fauna and lithology of
this unit is so distinctive that it should be given a distinguishing
name. The name Gadsden limestone is proposed for this deeper
water facies of Crystal River age because the fauna and lithology
of the unit was first described by Cole (1944) from the samples
of the City of Quincy water well, W-4, in Gadsden County.
As already noted, the Moodys Branch formation appears to be
absent in Jackson County. This would indicate that the Jackson
County section is minus the lower part of the Ocala Group (Moodys
Branch equivalents) or that the lower portion cannot be distin-
guished from the upper portion, and that it includes beds younger
than those exposed at Crystal River. Because the Bumpnose lime-
stone is equivalent to the youngest Eocene known in the Carib-
bean region, a combination of the sections in Jackson County and
those of the peninsular area of Florida include a complete Jackson
Eocene sequence. It should be pointed out, however, that the Jack-
son County section and the Citrus and Levy county sections of the
Crystal River are separated in the subsurface by the Gadsden lime-
stone so that the Crystal River cannot be traced directly from the
Peninsular area to the Jackson County area.
In this report the term Crystal River will be used to refer to all
of the Crystal River in Jackson County except where the Bumpnose
limestone member is referred to by its own member designation.
The Bumpnose limestone is considered to be a member of the
Crystal River formation, although it is younger than the youngest
Crystal River exposed at the type locality. A member designation
was chosen for the Bumpnose limestone rather than a formational
designation because of the limited geographic extent of the unit.

CRYSTAL RIVER FORMATION
Historical.-Florida Geological Survey Bulletins 21 and 29
should be consulted for more complete summaries of the earlier

GEOLOGY OF JACKSON COUNTY, FLORIDA

work with the Ocala group ("Ocala limestone"). Applin and Applin
(1944, p. 1683) divided the "Ocala limestone" into an upper and a
lower member, Vernon (1951, p. 111.) subdivided the "Ocala lime-
stone" into two formations, the "Ocala limestone (restricted)" and
the Moodys Branch formation. He subdivided the Moodys Branch
formation into a lower member, the Inglis, and an upper member,
the Williston. Puri (1953, p. 34) used the term Ocala group and de-
fined some of the units to be included in the Ocala Group. Puri pro-
posed the name Crystal River formation for Vernon's "Ocala (re-
stricted)" and raised Vernon's Inglis and Williston members to
formation rank.

In his study of the Oligocene stratigraphy of the Southeastern
United States, MacNeil (1944, pp. 1324-1325) questioned the
Jackson age assigned to the Lepidocyclina (Nephrolepidina) chaperi
Lemoine and R. Douvill6 zone (=L. (N.) fragilis Cushman). This
zone is the Bumpnose limestone member of this report. MacNeil
found associated with L. (N.) chaperi the following species:
Clypeaster sp., Pecten anatipes, and Spondylus dumosus, which
farther west in Alabama and Mississippi appear in unquestioned
Oligocene sediments. MacNeil correlates the L. (N.) chaperi zone
with the Red Bluff clay of Mississippi. In this report the L. (N.)
chaperi zone is considered to be of Jackson age, but it is treated as
a separate member of the Crystal River limestone, the Bumpnose
limestone member.

Definition.-The Crystal River formation of this report includes
all limestones containing Jackson Eocene orbitoid and camerinid
faunas that underlie the Marianna limestone or younger beds and
overlie the beds of Cook Mountain (lower middle Eocene) age with
Operculinoides sabinensis. The Bumpnose limestone member of
the Crystal River formation includes those soft, white, limestones
characterized by Lepidocyclina (Nephrolepidina) chaperi and over-
lain by the Marianna limestone with L. (Lepidocyclina) mantelli
and underlain by the harder cream-colored Crystal River limestone
bearing Operculinoides ocalanus, Operculina mariannensis, and
Asterocyclina spp.

Lithology.-The Crystal River formation is a white to cream-
colored, generally soft, granular, permeable, fossiliferous, pure
limestone. It is frequently composed almost wholly of the tests of
orbitoidal Foraminifera and Bryozoa. Frequently it has been
hardened by recrystallization to a dense limestone, and locally the

FLORIDA GEOLOGICAL SURVEY

exposed surface of the formation may be silicified, taking on a pink-
ish or brownish color.

The Bumpnose member is normally softer and whiter than the
Crystal River and is slightly glauconitic. The abundance of large
specimens of L. (N.) chaperi is a characteristic of the lithology of
the Bumpnose member.

Thickness and Structure.-Within Jackson County the Crystal
River formation has a thickness of about 220 feet including the
Bumpnose member. The top of the formation used in constructing
the structure map (Figure 6) is placed at the first appearance of
a Jackson Eocene fauna in the wells studied for this report. A
thin Ocala group section was observed in well W-1356, W-1358, and
possibly W-1364. A normal fault dipping to the southeast is
believed to explain best the observed thicknesses (see p. 26).

The structure of the Crystal River formation can be illustrated
best in sections, plates III, IV, and V (vertical scales exaggerated),
and by a structural map, figure 6. Regionally the Crystal River
formation dips southeast in the eastern part of the county and
south in the central and western parts of the county.

Paleontology.-The Crystal River formation, excluding the
Bumpnose member, is characterized by: Operculinoides ocalanus
(Cushman), Operculina mariannensis Vaughan, Asterocyclina spp.,
Pseudophragmina (Proporocyclina) citrensis (Vaughan), Lepi-
docyclina (Lepidocyclina) montgomeriensis Cole, L. (L.) ocalana
Cushman, and Amusium ocalanum Dall. Many species of echinoids
(Cooke, 1941, 1942) and mollusks are common. A check list of the
Foraminifera identified from various localities and wells in Jackson
County is given in Table 2. The fauna that is characteristic of the
Bumpnose member is listed under the discussion of that member,
and is not included here.

Local Details.-The Crystal River formation lies at or near the
surface over most of the northern half of Jackson County from
about three miles north of Marianna northward to the Alabama
Florida state line (Plate I). Outcrops of the Crystal River forma-
tion are scattered because of a veneer of terrace deposits. This area
has less relief than the southern half of the county where the more
impermeable Marianna limestone, the clayey phase of the Suwannee
limestone, and the clays of the Tampa formation crop out.

GEOLOGY OF JACKSON COUNTY, FLORIDA 33

Crystal River Gadsden
Formation Limestone
TABLE 2 Lower
TYPICAL OCALA GROUP Member
FORAMINIFERAL FAUNAS Bumpnose -5, J-156,
Member J-139, W-1987,
.-5 W-1824 278'-288'
Amphistegina alabamensis Applin & Jordan X X
Asterocyclina georgiana (Cushman) X
Asterocyclina nassauensis Cole X
Angulogerina byramensis (Cushman) X
Angulogerina vicksburgensis Cushman X
Anomalina bilateralis Cushman X X
Bolivina cf B. jacksonensis Cushman & Applin X X
Bolivina paula Cushman & Cahill X
Bolivina caelata Cushman X X
Bolivina byramensis Cushman X
Bolivina striatellata Bandy X
Bulimina ovata d'Orbigny X
Camerina vanderstocki (M. Rutten
& Vermunt) X
Cibicides mississippiensis (Cushman) X
Cibicides pippeni Cushman & Garrett X X
Cibicides pseudoungeriana (Cushman) X
Dentalina jacksonensis (Cushman & Applin) X
Dentalina cf. D. soluta Reuss X
Dentalina vertebralis (Batsch) X
Eponides jacksonensis (Cushman & Applin)
var. X X
Eponides cf. E. ocalanus Cushman X
Eponides cf. E. rutteni Cushman &
Bermudez, var. X
Gaudryina sp. X
Gaudryina gardnerae Cushman X
Globigerina spp. X X X
Globorotalia cocoanensis Cushman X
Guttulina byramensis (Cushman) X
Guttulina gibba d'Orbigny X X
Guttulina irregularis (d'Orbigny) X
Guttulina problema d'Orbigny X
Gypsina globula (Reuss) X X
Gyroidina sp. X
Gyroidina obesa Bandy X
Helicolepidina spiralis Tobler X
Liebusella byramensis turgida (Cushman) X
Lepidocyclina (Lepidocyclina) montgomeriensis
Cole X X
Lepidocyclina (Lepidocyclina) ocalana
Cushman X X
Lepidocyclina (Lepidocyclina) ocalana
floridana Cushman X

FLORIDA GEOLOGICAL SURVEY

Crystal River Gadsden
Formation Limestone
TABLE 2 (Continued) Lower
Member
TYPICAL OCALA GROUP Bumpnose J-5, J-156,
FORAMINIFERAL FAUNAS Member J-139, W-1987,
J-5 W-1824 278'-288'
Lepidocyclina (Nephrolepidina) chaperi
Lemoine & R. Douvill X
Lingulina sp. X
Marginulina cocoaensis Cushman X
Marginulina cf. M. digitalis Bandy X
Nodosaria cf. N. cookei Cushman X
Nodosaria fissicostata (Giimbel) X
Nodosaria latejugata Giimbel X
Operculina mariannensis Vaughan X
Operculinoides jacksonensis (Gravell &
Hanna) X
Operculinoides ocalanus (Cushman) X
Planorbulina larvata X
Planulina cf. P. cocoaensis Cushman X X
Pseudophragmina (Proporocyclina)
citrensis (Vaughan) X
Pyrgo inornata (d'Orbigny) X
Reussella eocena (Cushman) X
Robulus spp. X X
Robulus cocoaensis (Cushman) X
Robulus inusitatus Cushman X
Robulus limbosus (Reuss) X
Siphonina advena Cushman X X
Siphonina jacksonensis Cushman & Applin X
Textularia distinct (Cushman) X
Textularia mississippiensis Cushman X
Textularia seligi Stucky X
Uvigerina cocoaensis Cushman X
Uvigerina cookei Cushman X
Uvigerina dumblei Cushman & Applin X
Uvigerina glabrans Cushman X X
Uvigerina jacksonensis Cushman X
Valvulineria octocamerata (Cushman &
Hanna) X X

Loc. J-2, a sink hole, in the center of the E 1l/ NE 1/4 sec. 31,
T. 6 N., R. 9 W. exposes 12 feet of upper Crystal River formation.
The elevation of the land surface at the side of the sink is about 125
feet. Only a small amount of overburden is present.
Loc. J-5, a quarry, figure 7, near the center W 1/. sec. 23, T. 5 N.,
R. 11 W. exposes approximately 2 feet of Crystal River formation
at the bottom of the pit in the floor of the north quarry with
Amusium ocalanum and Asterocyclina sp. Near the bottom of the

GEOLOGY OF JACKSON COUNTY, FLORIDA

small pit in the floor of the north quarry, the Crystal River forma-
tion is overlain by approximately 15 feet of the Bumpnose member.
This is probably the best locality in Jackson County to study the
relationships between the Crystal River formation, the Bumpnose
member, and the Marianna limestone.
Loc. J-11, an abandoned quarry, at the road corner in the SE
1/4 SW 1/4 sec. 29, T. 6 N., R. 11 W. exposes approximately 15 feet
of the Asterocyclina zone of the Crystal River formation. Echinoids
are abundant in this quarry.
Loc. J-12, an abandoned quarry, just east of the highway (Fla.
75-U.S. 231) in the SE 1/ sec. 13, T. 6 N., R. 12 W. exposes about
15 feet of the uppermost Crystal River overlain by 5 feet of hard
limestone of the Bumpnose member. Figure 8 shows the discon-
formity between the lower portion of the Crystal River formation
and the Bumpnose member. MacNeil (1944, p. 1325) refers the
upper bed to the L. (N.) chaperi zone. Cooke (1945, p. 67) listed
a large thick Lepidocyclina sp., Pecten poulsoni, Clypeaster sp.
(probably C. rogersi) from this bed and regarded it as an unmapped
outlier of the Marianna limestone. Cooke does not now include the
L. (N.) chaperi zone in the Marianna limestone.1
Loc. J-138, a sinkhole, just north of the road in the southeast
corner of the SW 1/4 sec. 23, T. 6 N., R. 9 W. exposes 8 feet of hard
crystalline limestone that contains Amusium ocalanum of Crystal
River age. The elevation of the land surface at the top of the sink
in 128 feet. This limestone trends generally north-south and the
outcrop has a width of about 50 feet.
Loc. J-139, a deep sinkhole, on the west side of the road at NE
1/4 NE 1/ sec. 21, T. 6 N., R. 9 W. exposes 27 feet of the Asterocy-
clina zone of the Crystal River formation. The elevation at the top
of the sink is 130 feet. This is an excellent exposure of the Crystal
River formation and is very fossiliferous.
Loc. J-150, a sinkhole, in a field in the NW 1/ NW 1/4 sec. 10, T. 5
N., R. 9 W. exposes about seven feet of Crystal River formation over-
lain by 3 feet of mantle. The elevation of the land surface at the
top of the sink is 112 feet.
Loc. J-156, an abandoned quarry, north of Waddell's Mill Pond
in the NE 1/ SE 1/ sec. 32, T. 6 N., R. 11 W. exposes about 35 feet
of the Asterocyclina zone of the Crystal River formation. The ele-

1Personal communication.

FLORIDA GEOLOGICAL SURVEY

vation of the top of the limestone is estimated to be 120-130 feet.
In the upper 20 feet Asterocyclina sp. is very abundant. The check-
list (table 2) includes species that have been identified from this
locality. This is one of the best Crystal River formation exposures
in Jackson County (Stop No. 8, Southeastern Geological Society,
Third Field Trip, Western Florida, p. 18, Nov. 9, 10, 1945).

Loc. J-157, a sinkhole, on the south side of the road, SW 1/4 NE
1/4 sec. 36, T. 6 N., R. 9 W., exposes 9 feet of the Asterocyclina zone
of the Crystal River formation. The elevation of the top of the sink-
hole is about 130 feet.

Loc. J-185, a bluff, on the west side of the Chipola River flood-
plain SE 1/4 sec. 28, T. 5 N., R. 10 W. exposes the Asterocyclina zone
of the Crystal River formation. Asterocyclina spp. occur just above
the level of the floodplain.
Thirty-five wells that reached the Crystal River formation are
listed in Appendix I, where the depth at which the formation was
encountered is indicated.

Bumpnose Member of the Crystal River formation
Historical.-The limestone herein called the Bumpnose was first
included in a section published by Cooke (1915, p. 109). The details
of Cooke's section follow:

"Section 200 yards below the wagon bridge east of
Marianna, Fla.
Marianna limestone: Feet
5. White limestone, the same as bed No. 5
of the section at the bridge ------ 33
Ocala limestone:
4. Soft cream-colored limestone with several
species of Orbitoides and some Bryozoa ..--- 1
3. Hard semicrystalline pinkish limestone
with large Orbitoides, Flabellum and
Amnusium ocalanum ____----------- 61/2
2. Soft granular cream-colored limestone
like No. 1 of section at bridge but with
fewer Foraminifera. Contains Orbitoides
(stellately marked species), Flabellum,
Bryozoa, Terebratulina lachryma?, Nati-
ca, Arca, Pecten indecisus, Amusium
ocalanum and Plicatula (Ocala species) --.- 3
1. Concealed to water level in Chipola River 3"

Cushman (1920, pp. 63-64) described Lepidocyclina fragilis
[L. (Nephrolepidina) chaperi of this report] from bed four of the
above section. As Cooke considered this bed to be Ocala in age,
L. (N.) chaperi was thought to be a marker for the upper "Ocala

GEOLOGY OF JACKSON COUNTY, FLORIDA

limestone." The age of this zone was not questioned until MacNeil
(1944, p. 1324) found species associated with L. (N.) chaperi which
farther west appear to be confined to the Oligocene. MacNeil cor-
related this horizon with the Red Bluff clay of Alabama and Mis-
sissippi.
Cole (1945, pp. 17-19) reported Lepidocyclina (Nephrolepidina)
sanfernandensis Vaughan and Cole, var. tallahasseensis Cole and
Helicolepidina paucispira Barker and Grimsdale from the bottom
of the City of Tallahassee water well, W-453. Helicolepidina pau-
cispira at that time was known to occur only at the base of the upper
Eocene in Mexico (Barker and Grimsdale, 1936, pp. 243, 247). L.
(N.) sanfernandensis was known only from the type locality at San
Fernando, in Trinidad, in deposits considered to be of late Eocene
age. As this fauna was not typical of any known locality in the
"Ocala limestone," Cole referred that portion of the well to the
upper Eocene without a specific formational designation. Cole
(1952, pp. 23-27) has shown that L. (N.) fragilis and L. (N.) san-
fernandensis var. tallahasseensis are synonyms of L. (N.) chaperi.
At locality J-5 in Jackson County, Florida, (fig. 7) specimens of
Helicolepidina spiralis Tobler were found in association with Lepi-
docyclina (Nephrolepidina) chaperi Lemoine and R. Douvill6, Lepi-

Srj .k 'L
..w

4* -,~ ...
j M
r'vio

Figure 7.-Locality J-5, Marianna Limestone Products Co. Rock being
quarried is Lepidocyclina (Nephrolepidina) chaperi zone, the Bumpnose mem-
ber, and the Crystal River formation.

FLORIDA GEOLOGICAL SURVEY

docyclina (Lepidocyclina) montgomeriensis Cole, L. (L.) georgiana
Cushman, and L. (L.) ocalana Cushman. Further, the matrix
around a nautiloid specimen, Aturia alabamensis, which came from
the uppermost part of the Bumpnose limestone at this locality,
contained specimens of Helicolepidina spiralis, L. (L.) montgomer-
iensis, and L. (N.) chaperi. The faunal checklist (table 2) indi-
cates the various species which have been found in the Bumpnose
limestone.
The late Professor G. D. Harris and Dr. K. V. W. Palmer kindly
consented to examine the pelecypods and gastropods although pres-
ervation of the latter was so poor that specific identifications were
not possible. Professor Harris' opinion of this pelecypod fauna
is quoted:'
"Our interpretation of your material is that it came from Ocala beds in
which Oligocene species were gradually infiltrated."
When compared with the Crystal River large Foraminifera
fauna immediately underlying the Bumpnose limestone, the fauna
of the Bumpnose limestone indicates a loss of Asterocyclina, Pseudo-
phragmina, and Operculinoides species, the retention of Lepido-
cyclina (Lepidocyclina) montgomeriensis, L. (L.) georgiana, and
L. (L.) ocalana, and the additions of Helicolepidina spiralis, else-
where considered to be restricted to the Eocene, and Lepidocyclina
(Nephrolepidina) chaperi, the first appearance of the subgenus,
but a species which in Panama and elsewhere is associated with
typical Jackson stage Eocene genera and species including Astero-
cyclina species, (Cole, 1952, p. 4). Careful examination revealed
no specimens of previously accepted Oligocene species of large
Foraminifera in the Bumpnose member.
MacNeil (1944, p. 1325) refers the upper limestone member
which unconformably overlies the Crystal River limestone (fig. 8)
in an abandoned quarry (locality J-12 of this report) to the L. (N.)
chaperi zone. Cooke (1945, p. 67) considered this same member to
represent the Marianna limestone.
C. Wythe Cooke (letter, May 1, 1952), after examining two
echinoid species from the Bumpnose limestone at locality J-5, stated:
"The occurrence in this zone of a Clypeaster and Pecten anatipes as
reported by MacNeil is very suggestive of Oligocene age, though I agree
with him that the zone does not belong in the Marianna Limestone. His
suggestion that it should be correlated with the Red Bluff clay, which
is supposed to be early Oligocene, seems very plausible. The known fauna
of the Red Bluff has some Eocene aspects."
tPersonal letter dated November 7, 1950, a copy of which is on file at the
Florida Geological Survey.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Figure 8.-Locality J-12. The uppermost bed is the Lepidocyclina (Nephro-
lepidina) chaperi zone. The lower rock is more typical of the Crystal River
formation.

Cooke reports the two echnoid species as new species of Aniso-
petalus and Clypeaster (closely related to C. rogersi).
It is my opinion that this zone is of uppermost Jackson age,
rather than of Oligocene age as suggested by MacNeil. It must be
recognized, however, that there seems to be an infiltration of Oligo-
cene forms and that this represents a transition between the two
series.
The upper contact of the Bumpnose limestone can be observed
best at locality J-74, where it is conformably overlain by the Mari-
anna limestone. The uppermost part of the Bumpnose limestone is
glauconitic as it is at locality J-5. The base of the Bumpnose lime-
stone can be seen at locality J-5 but quarrying operations tend to
obscure the contact. At locality J-12, however, the base of the
Bumpnose limestone is clearly exposed, and it is slightly unconform-
able (fig. 8) with the underlying Crystal River formation.
The distribution of the Bumpnose limestone in Florida is re-
stricted. It appears to be present at the surface only on the
Marianna-Chipley structural high and in the subsurface in the
Tallahassee area. Wells in Washington County have not been
studied to verify its presence there, but it probably does extend

FLORIDA GEOLOGICAL SURVEY

into Washington County. The Bumpnose limestone was not recog-
nized in well W-1987 at Sink Creek, where a somewhat deeper water
Jacksonian fauna was encountered, but a new species, probably
belonging to the Amphisteginidae, that occurs in the Bumpnose
limestone, was present in the well at the stratigraphic position of
the formation.

This restriction of the Bumpnose limestone to the structurally
higher areas in west Florida, the prolific occurrence of the one
species, L. (N.) chaperi, and the abundant bryozoans of the zone
suggests that this zone represents a distinct biofacies of the upper-
most Jacksonian.

Definition.-The Bumpnose limestone member of this report,
a new name, is the uppermost member of the Crystal River forma-
tion and contains Lepidocyclina (Nephrolepidina) chaperi Lemoine
and R. Douvill&. It occurs above the Asterocyclina zone of the
Crystal River formation and below the Marianna limestone which
contains Lepidocyclina (Lepidocyclina) mantelli (Morton). The
member is named for the many occurrences in the general vicinity
of the Bumpnose road north of Marianna. Locality J-5 is the type
locality for the member.

Lithology.-The Bumpnose limestone is a soft, easily crumbled,
white limestone that is generally more granular than the typical
Marianna limestone because of the presence of many Bryozoa and
Foraminifera. It is generally somewhat glauconitic, especially near
the top of the member.

Thickness.-The thickness of the Bumpnose limestone ranges
from 0 to 15 feet in Jackson County. It apparently thins to the
southeast where it is replaced by the Gadsden limestone southeast of
the Cypress fault.

Paleontology.-The striking and characteristic feature about
the fossils of this horizon is the abundance of specimens of Lepi-
docyclina (Nephrolepidina) chaperi Lemoine and R. Douvill6 with
a virtually bewildering variation in shape. Bryozoa are present
in large numbers and several species are represented. The checklist
(table 2) indicates the species which were determined. A new
amphisteginid species whose affinities are not yet clear appears to
be restricted to this horizon though its areal distribution is greater
than L. (N.) chaperi.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Local Details.-A quarry (loc. J-5) located near the center of
the W 1/2 sec. 23, T. 5 N., R. 11 W. exposes 15 feet of the Bumpnose
limestone. The elevation of the top of this formation is 115 feet.
A small pit located within a larger quarry, is now being mined at
this site. This elevation corresponds with the floor of the large
quarry and the rim of the smaller pit, (fig. 7). This is the best ex-
posure of the Bumpnose limestone in Jackson County since the zone
is overlain by the Marianna limestone and underlain by about 2
feet of Crystal River formation. The following section was mea-
sured at locality J-5 in 1948:

Loc. J-5
Top of quarry face.
Marianna limestone Feet
10. Hard, weathered limestone 2.0
9. Soft, creamy white limestone with scattered
Lepidocyclina (Lepidocyclina) mantelli,
Operculinoides dius, and Pecten. 5.2
8. Hard lenses made up of L. (L.) mantelli 1.0
7. Soft "chimney rock" phase of Marianna ls. 5.4
6. Soft, "chimney rock" matrix with many specimens of
L. (L.) mantelli 2.0
5. Soft, creamy white "chimney rock" as in bed 7 5.4
Unconformity?
Crystal River formation
Bumpnose member
4. Soft to hard, fine to granular white limestone, upper
6 inches glauconitic, becoming less so toward bottom of
member. L. (Nephrolepidina) chaperi and mollusk molds
abundant. Aturia alabamensis collected near top of bed. 5.4
3. Granular, white, very fossiliferous limestone, L. (N.)
chaperi, very abundant with many very large micro-
spheric specimens, and Pecten anatipes. 5.4
2. Harder, creamy white limestone with fossils as in bed 3. 5.4
Unconformity
Lower member of Crystal River formation
1. Hard, buff to cream colored limestone with Amusium
ocalanum. No Lepidocyclina noted. 2.0
Total thickness of section ............ .. ... ------39.2
The checklist (table 2) shows the species which have been identified
from this quarry.

Loc. J-74, a bluff, just northeast of the highway Fla. 73 in the
southeast corner NW 1/4 sec. 25, T. 5 N., R. 11 W. exposes 10 feet
of the Bumpnose limestone. The limestone lying above the Bump-
nose limestone and extending to the top of the bluff is referred to
the Marianna limestone, but the Southeastern Geological Society
(1945, p. 16, Stop. No. 7) referred this to the Byram marl. The
elevation of the top of the bluff is about 135 feet and the elevation
of the contact between the Bumpnose limestone and the Marianna
limestone is 106 feet.

FLORIDA GEOLOGICAL SURVEY

Loc. J-77, a roadside exposure, in the NW 1/4 SE 1/4 sec. 29, T.
5 N., R. 10 W. exposes the contact between the Marianna limestone
and the Bumpnose member. The elevation of the contact, at the
foot of the hill, is 93 feet.
Loc. J-97, a roadside outcrop, at the center of the east side of
the SE 1/ sec. 20, T. 5 N., R. 10 W. exposes an obscure contact be-
tween the uppermost portion of the Bumpnose limestone and the
basal portion of the Marianna limestone. A little over 5 feet of hard
cherty limestone assigned to the Bumpnose limestone is exposed in
the roadbed at the gate to the superintendent's house, Florida
Caverns Park.
Loc. J-149, a sink, in the SW 1/4 NE 1/4 sec. 9, T. 5 N., R. 9 W. ex-
poses 5 feet of the Bumpnose limestone overlain by one or two
feet of mantle rock. The elevation of the land surface at the top
of the sink is 132 feet.
Loc. J-193, a small sinkhole, in a field in the NW 1/4 SE 1/t sec.
15, T. 5 N., R. 9 W. exposes two or three feet of the Bumpnose
limestone. The elevation of the top of the limestone is 116 feet.
The Bumpnose limestone was readily recognizable in wells and
it was logged in the following wells: W-276, W-1356, W-1783, W-
1793, W-1794, W-1824, W-2252, W-2328, W-2415, W-2433, and
W-2531. Appendix I gives the depths at which it was encountered
in each case.
GADSDEN LIMESTONE
Historical.-The Gadsden limestone is a new name introduced
here for some limestones of Jackson age that occur in the subsurface
sections of southeastern Jackson County. These limestones have a
foraminiferal fauna dominated by the families Buliminidae and
Lagenidae. The Foraminifera Lepidocyclina, Asterocyclina, and
Operculinoides are generally absent in the Gadsden limestone.
Dense brown chert is present in the upper part of the Gadsden lime-
stone, and the Gadsden limestone is finer grained than the limestone
of the Crystal River formation because of the absence of the larger
Foraminifera. Well W-4, the City of Quincy water well in Gadsden
County, is designated as the type well, and the interval from 680
feet to at least 900 feet in this well is assigned to the Gadsden lime-
stone. Samples from this well are on file at the Florida Geological
survey. The top of the Gadsden limestone is easily determined in
well W-4 and in most of the wells studied, but, unfortunately, the
bottom of the formation is not so obvious in well W-4. The Applins

GEOLOGY OF JACKSON COUNTY, FLORIDA

(1944, p. 1678) indicate that Eponides aff. cocoaensis is one of the
key fossils for the Tallahassee limestone, which underlies the Gads-
den limestone in well W-4. E. cocoaensis appears at 900 feet in
well W-4, but there is little else to mark the bottom of the Gadsden
limestone, and it may extend deeper than indicated above.
The limestones that are referred to here as the Gadsden lime-
stone were first described by Cole (1944, p. 11-18) from the City
of Quincy water well W-4. Cole applied the name "Ocala" to the
rocks below 680 feet in well W-4, but he noted that the fauna was
not that of the typical "Ocala limestone" elsewhere in Florida, be-
cause it contained no large Foraminifera. Applin and Applin (1944,
p. 1736) accepted Cole's "Ocala" designation for a part of the
Eocene section of well W-4, but they assigned only the interval from
650 feet to 910 feet to the "Ocala." The Applins placed the top of
the "Ocala" thirty feet higher than Cole had placed it, and they as-
signed the lower part of the section, below 910 feet, to the Talla-
hassee limestone. The samples from well W-4 have been examined,
and the top of the Gadsden limestone (="Ocala") is placed at a
depth of 680 feet. The bottom of the Gadsden is placed tentatively
at 900 feet, and it is believed to extend somewhat lower in the well,
but a clearcut bottom for the Gadsden limestone could not be located
in this well. No more than an additional 20 to 30 feet would be in-
cluded in the Gadsden limestone. Not all of the lower part of the
well to the total depth of 1395 feet belongs in the Jackson stage.

Definition.-The Gadsden limestone in Jackson County consists
of those limestones of Jackson age that have no, or few, specimens
of the larger Foraminifera such as Lepidocyclina, Asterocyclina, or
Operculinoides. The Gadsden limestone is known to occur only in
the subsurface at present. The foraminiferal fauna of the Gadsden
limestone is dominated by the families Buliminidae and Lagenidae,
which make up from 40 to 50 percent of the foraminiferal popula-
tion. The Gadsden limestone is overlain in Jackson County by the
Marianna limestone. The Gadsden limestone is the stratigraphic
equivalent of the Crystal River formation, which includes the Bump-
nose member. The Gadsden limestone grades laterally into the Crys-
tal River formation in Jackson County, and the youngest beds of the
Gadsden limestone extend farthest to the northwest (Plate IV). De-
pending upon where the Gadsden limestone is encountered in wells,
it is underlain by the Crystal River formation or by older Eocene
formations. The Tallahassee limestone underlies the Gadsden lime-
stone in well W-4 in Gadsden County.

FLORIDA GEOLOGICAL SURVEY

Lithology.-The Gadsden limestone is a buff to white limestone
that is porous, soft, and fine grained. Near the top of the Gadsden
limestone there is a zone of dense, brown chert that was not noted
in the Crystal River limestone. Selenite occurs in the Gadsden
limestone in well W-4, but none was noted in Jackson County.

Thickness and Structure.-The Gadsden limestone ranges from
0 to 180 feet in thickness in Jackson County. The Gadsden lime-
stone is confined to the area southeast of the Cypress fault, and
from the fault it thickens to the southeast at the expense of the
Crystal River formation, with which it is equivalent. The Gadsden
limestone occurs only on the downthrown side of the Cypress fault,
and aside from the nose, shown on structure map figure 6, the
Gadsden limestone dips to the southeast.

Paleontology.-The Gadsden limestone does not contain the
large Foraminifera that are typical in rocks of Jackson age in
Florida. Instead, it carries a fauna composed primarily of the
foraminiferal families Buliminidae and Lagenidae. The abundance
of Jacksonian species of Uvigerina, Bulimina, Bolivina, Dentalina,
Nodosaria, Marginulina, and Robulus is noteworthy and typical.
These elements of the fauna may constitute 40 to 50 percent of the
total foraminiferal fauna. Table 2 indicates species that have been
identified from the Gadsden limestone.

Local Details.-The Gadsden limestone was encountered in all
wells southeast of the Cypress fault that encountered rocks of
Jackson age. As indicated in Plate IV, the formation thickens to
the southeast at the expense of the Crystal River formation. Ap-
pendix I lists all wells studied that penetrated the Gadsden lime-
stone.
OLIGOCENE SERIES
VICKSBURG GROUP

MARIANNA LIMESTONE
Historical.-Florida Geological Survey Bulletins 21 and 29 con-
tain historical summaries pertaining to the Marianna limestone.

Definition.-The Marianna limestone of this report consists of
the light-colored limestones which carry Lepidocyclina (Lepido-
cyclina) mantelli (Morton), and which are underlain by the Crystal
River limestone or the Gadsden limestone, and which are overlain
by the Suwannee limestone.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Lithology.-The Marianna limestone is always light in color,
ranging from white through cream to light gray. It is slightly
glauconitic, and when this rock has been subjected to alternate wet-
ting and drying, as in a poorly drained quarry, it may have rust
colored specks scattered through it. The Marianna limestone en-
countered in well W-1987 in Sink Creek was especially glauconitic.
The limestone is generally massive and impermeable. The large
Foraminifera which characterize the Marianna limestone may be
virtually the sole constituents of some beds. The Marianna lime-
stone is very soft when fresh, and wood saws are used to cut out
pieces for use as building blocks.

Thickness and Structure.-The Marianna limestone strikes east-
west, where exposed at the surface, with only minor variations
(figure 9). The dip is about 13 feet per mile to the south and
steepens to 64 feet per mile at about the south side of T. 4 N. south
of Marianna. This observation is based upon dips of the Suwannee
limestone measured along the Chipola River north of Sink Creek
and the depth of the Marianna limestone in well W-1987 at Sink
Creek. The steeper dip at Sink Creek probably resulted from
drag associated with the Cypress fault.
The thickness is rather uniform, ranging from at least 25 feet
in well W-1987 at Sink Creek to about 35-40 feet in the outcrop
area.

Paleontology.-The Marianna limestone has an abundant fora-
miniferal fauna. Cole and Ponton (1930, pp. 22-23) reported 58
species and varieties of Foraminifera from the Marianna in their
report but the large Foraminifera, especially Lepidocyclina (Lepi-
docyclina) mantelli (Morton) associated with Operculinoides dius
(Cole and Ponton) remain the best guide to the formation.
Bryozoa are abundant locally and Pecten sp. is found at most
localities.

Local Details.-The Marianna limestone, especially where cov-
ered with either the clayey phase of the Suwannee limestone or Mio-
cene clays, forms an escarpment which extends in an east-west
direction from the vicinity of Blue Springs to Cottondale, Florida.
It is in this area that most good exposures occur. The City of
Marianna is on the top of this escarpment, and excellent outcrops
are to be found especially northeast and northwest of Marianna
along the dissected front of the escarpment (Plate 1). The dense,

STRUCTURE MAP

OF THE
MARIANNA LIMESTONE
cAntou dTSM mao s*e Ilerl
--t0O- COTTOUR TTED WHERE UNfRTAIN
.A.A LWIMT OF OUTCROP
0 WELL SAMPLE
X SURFACE OUTCROP
-- PROBABLE PRE.TAMPA POST SUWANNEE FAULT

SCALE

Z- '; -2,I,

I R 7 I 1 6 I T t T A 4 I R 3 W

Figure 9.-Structure map of the Marianna limestone.

w j R F2 W I N D W R
S-

R sa w ( R a3

- -- I o n

GEOLOGY OF JACKSON COUNTY, FLORIDA

massive character of the "chimney rock" facies of the Marianna
limestone tends to make it impermeable to the general percolation
of water through the rocks so that it reacts as a resistant unit,
especially where overlain by impervious clays. The Marianna lime-
stone was identified in the subsurface as far south as Sink Creek
from well cuttings.
Loc. J-189, a sinkhole on the south side of the road in the NE 1/4
NW 1/4 sec. 22, T. 5 N., R. 9 W., exposes 6 feet of badly weathered
Marianna limestone. The elevation of the road alongside the sink
is 115 feet.
Loc. J-1, a chimney rock quarry west of the highway (Fla. 71)
in the NW 1/ NW 1/, sec. 30, T. 5 N., R. 9 W., exposes 19 feet of
the chimney rock phase of the Marianna limestone, overlain by one
to five feet of red residual soil.
Loc. J-78, a road cut, on highway Florida 164 in the approximate
center of sec. 32, T. 5 N., R. 9 W. shows the Marianna limestone-
Suwannee limestone contact. About five feet of Marianna limestone
is overlain by three or four feet of tan, clayey, dolomitic limestone
(figure 10). The elevation of this Marianna limestone-Suwannee
limestone contact is 127 feet.

Figure 10.-Suwannee limestone at locality J-78 is overlain by "bentonitic"
clays and terrace deposits. The dark halo surrounding the white rock is the
"bentonitic" clay. The Marianna limestone at this locality is not shown in
this picture.

FLORIDA GEOLOGICAL SURVEY

Loc. J-79. At Blue Spring, near the center of the W 1/2 sec. 33, T.
5 N., R. 9 W., 29 feet of Marianna limestone is exposed from the
spring to the top of the hill. The elevation of the water at the spring
is 82 feet. The underground channel from which the spring emerges
is probably in the Bumpnose limestone.
Loc. J-190, a deep sinkhole at the north edge of the road in the
NW 1/4 NW 1/4 sec. 35, T. 5 N., R. 9 W., exposes 20 feet of Marianna
limestone.
Loc. J-14, a road cut on highway U. S. 90 immediately west of
the Chipola River bridge, exposes 19 feet of Marianna limestone
(figure 11). Cooke (1945, p. 80) published the following general-
ized section for this immediate area.
Section on Chipola River at Marianna Feet
3. Byram limestone (Oligocene): finely granular crystalline
limestone like that exposed along Chipola River south of
Marianna. Pecten aff. P. poulsoni and impressions resem-
bling Lepidocyclina supera. Exposed in the cut on High-
way 90. About .-...______--------_____.. -------- 3
2. Marianna limestone (Oligocene) : Massive, homogeneous
white chalky limestone containing Lepidocyclina mantelli
and Pecten poulsoni About ... .....--------- --- 30
Unconformity
1. Ocala limestone (Eocene) : Soft granular white limestone
with hard ledges in upper part. Composed chiefly of cal-
careous organisms locally cemented, including Flabellum
sp., Terebratulina lachryma?, Amusium ocalanum, Plica-
tula sp., and the larger Foraminifera listed on page 67.
Lepidocyclina fragilis at the top to water level, About .---- --- 14

Figure 11.-Locality J-14. Marianna limestone
east of Marianna on highway U. S. 90.

at Chipola River bridge

GEOLOGY OF JACKSON COUNTY, FLORIDA

The upper 12 feet of bed 1 of the above section is the Bumpnose
member of this report and the lower 2 feet of bed 1 is the lower
member of the Crystal River limestone.
The Marianna limestone crops out along the Chipola River as
far south as the SW 1/4 sec. 14, T. 4 N., R. 10 W. There is an abon-
doned chimney rock quarry (J-19) on the west bank of the river
where the L & N railroad bridge crosses the Chipola River near the
center Sl/2 NE 1/4 sec. 10, T. 4 N., R. 10 W.
A number of good exposures of the Marianna limestone and
the overlying Suwannee limestone can be seen along the graded
road north from the western edge of Marianna. One good section
is locality J-76, near the center W 1/2 SE 1/4 sec. 29, T. 5 N., R. 10
W., elevation 122 feet.
The Marjax Co. has a new quarry located in the NW 1/4 SW 1/4
sec. 30, T. 5 N., R. 10 W., not shown on the map, that exposes 12
feet of the Marianna limestone. This quarry was opened after the
field work was completed, and it was not visited.
Loc. J-13, a roadside cut, two miles north of Marianna, measured
from the junction of Florida 167-U. S. 90 on Fla. 167, exposes 28
feet of Marianna limestone overlain by about 16 feet of Suwannee
limestone. The elevation of the Marianna-Suwannee limestone con-
tact is 113 feet. MacNeil (1944, p. 1331) and the Southeastern
Geological Society (1945, p. 19) published sections from this locality,
the best for study of the overlying clayey beds of the Suwannee
limestone (figure 12).
Loc. J-74. A roadside exposure on the north side of the highway
(Fla. 73) in about SE corner NW 1/ sec. 25, T. 5 N., R. 11 W. ex-
poses about 5 feet of Marianna limestone. The elevation of this
roadside exposure is 116 feet. In the woods to the northeast of the
road, a bluff, that cannot be seen from the road exposes about 40
feet of white limestone. The upper 30 feet of this section is re-
ferred to the Marianna limestone, the lower 10 feet is the Bumpnose
member. The elevation of the top of the bluff and top of the lime-
stone is 135 feet. This locality is Stop No. 7 of the Southeastern
Geological Society, Third Field Trip, (1945, p. 16).
Loc. J-5. Two limestone quarries, owned by the Marianna
limestone Products Co., near the center W 1/ sec. 23, T. 5 N., R.
11 W., expose about 40 feet of Marianna limestone overlying the
L. (N.) chaperi zone. The elevation of the top of the Marianna
limestone in the south quarry is 157 feet. A measured section at

FLORIDA GEOLOGICAL SURVEY

Figure 12.-Locality J-13. Marianna limestone overlain by Suwannee
limestone.
the north quarry is to be found on p. 41 of this report. As stated
before, this locality shows the relationships between the Marianna
limestone and the Bumpnose member very clearly.
Several exposures of Marianna limestone are to be found
on a little traveled dirt road running east-west parallel to U. S.
90 and lying about one and one-half miles north. Loc. J-173, a
roadside exposure at the center of the east side of the NE 14 sec.
27, T. 5 N., R. 11 W., exposes about 5 feet of Marianna limestone
overlain by 5 feet of what is believed to be Suwannee limestone.
The elevation of the contact between the two beds is 137 feet. Loc.
J-174, a road cut at about the center of the NE 1/4 sec. 27, T. 5 N., R.
11 W., exposes 20 feet of Marianna limestone overlain by 2 feet of
what is believed to be Suwannee limestone. The elevation of the top
of the limestone in this section is 137 feet.
Loc. J-86, on the side of a hill just north of the L & N railroad
tracks at the southwest corner of the NW 1/ NW 1/ sec. 32, T. 5
N., R. 11 W., 15 feet of Marianna limestone is exposed. The eleva-
tion at the top of the Marianna limestone is 136 feet. A well W-1783,
at the top of the hill just north from this locality encountered the
Marianna limestone at essentially the same elevation. The Marianna
limestone is apparently 40 feet thick at this point (W-1783).

--- 140ft Blow

GEOLOGY OF JACKSON COUNTY, FLORIDA

The following wells penetrated the Marianna limestone: W-l,
W-4, W-276, W-1356, W-1357, W-1358, W-1359, W-1360,
W-1361, W-1362, W-1363, W-1364, W-1783, W-1793, W-1794,
W-1824, W-1987, W-2252, W-2328, W-2329, W-2373, W-2415,
W-2433, and W-2531. Appendix I gives the depth at which the
formation was encountered.

VICKSBURG GROUP AND CHICKASAWHAY MARL
SUWANNEE LIMESTONE
Historical.-Excellent historical summaries relating to the
Suwannee limestone are to be found in Florida Geological Survey
Bulletins 21 and 29. MacNeil (1944, p. 1313-1314, footnote 3)
considered the Suwannee limestone of western Florida to be the
equivalent of the Byram and Chickasawhay formations com-
bined.

Definition.-The Suwannee limestone, as exposed in Jackson
County, consists of tan to buff-colored limestones, dolomitic lime-
stones, and dolomitic to calcareous clays that underlie the greenish-
gray to white Tampa formation. The Marianna limestone under-
lies the Suwannee limestone.

Thickness and Structure. The Suwannee limestone in Jackson
County was subjected to erosion before Miocene deposition began
so that its thickness ranges from 5 to 12 feet in the central area
of the County near Marianna and Cottondale to a maximum thick-
ness in a water well, W-1987, at Sink Creek of about 210 feet.
The Suwannee limestone and the underlying sediments were
gently flexed and faulted during the interval between the Oligocene
and the Miocene, though there is some evidence along the Chipola
River in Calhoun County to the south that this movement may have
continued for some time into the Miocene (figure 13, Plate III).
North of the Sink Creek bridge across the Chipola River the dip
of the Suwannee beds can be observed (figure 14). It is necessary
to use the measured dip of these beds, 64 feet per mile, in construc-
ting a structure section if the observed thickness of the Suwannee
limestone in W-1987 at Sink Creek is to be reconciled with the cal-
culated dip of 12-15 feet per mile on the top of the Marianna lime-
stone in the vicinity of the town of Marianna, (Plate III, see p.
45). South from Sink Creek the dip must lessen once more to
about the regional dip in order to correlate with the section found
in the oil test well, W-7, near Clarksville. That such a flexure has
occurred is further indicated by the rectangular stream course of

FLORIDA GEOLOGICAL SURVEY

Figure 13.-One of a series of gentle arches in the Tampa formation just
south of Jackson County in Calhoun County on the Chipola River. North is
to the right in the picture.

_.,
4 ... ,, '-- --

Figure 14.-Dip of Suwannee limestone at Sink Creek bridge on the Chip-
ola River.

GEOLOGY OF JACKSON COUNTY, FLORIDA

the Chipola River, probably caused by jointing, north of Sink
Creek in the S 1/2 sec. 2, sec. 11, sec. 12, and the N 1/2 sec. 13, T. 3.
N., R. 10 W. This rectangular stream course is best seen on air-
plane photographs, and figure 2 is traced from the aerial photo-
graph mosaic of the U. S. Department of Agriculture photographs
of Jackson County. In sec. 19, T. 2 N., R. 9 W. in Calhoun County
the Chipola River again assumes a more tortuous course than is
normal and small arches of the Tampa formation can be observed
along the river, figure 13.
The nature of the structure of the Suwannee limestone is un-
known in the southwestern part of the country. A few samples
from a well at Compass Lake contained two consecutive samples
which straddled the Suwannee-Tampa contact. Reports from var-
ious water well drillers regarding the top of the "rocks" in wells
along the highway from Compass Lake to Cottondale confirmed
field observations that the top of the Oligocene had been eroded.
The Oligocene-Tampa contact appears to be along an unconformity
in this area (Structure Section, Plate V). The thickness of the
Suwannee limestone in the southwestern part of the county is
unknown. A well at the Florida State Hospital farm, W-276, in
the eastern part of the county shows 115 feet of Suwannee lime-
stone. Figure 15 shows the configuration of the surface of the
Oligocene limestone, usually the top of the Suwannee limestone.

Paleontology.-Table 3 shows the faunas determined for the
Suwannee limestone at various localities and wells.

TOP OF
OLIGOCENE SEDIMENTS
Contour dAolun .Nn s.. level
-'Io- CONTOUR OOTTEL WHERE UNCERTAIN
UIJU4 LIMIT OF OUTCROP
o WELL SAMPLE
X SURFACE OUTCROP
- PROBABLE PRE.TAMPA POST SUWANNEE FAULT

SCALE
4 4 2Mi

R 4 I iFigure 15 I I RO R 9 tp of O cene sedme

Figure 15.-Map, top of Oligocene sediments.

W I R 3 W

- - ^ r I D r u

GEOLOGY OF JACKSON COUNTY, FLORIDA 55

TABLE 3
SUWANNEE LIMESTONE FORAMINIFERAL CHECKLIST

J-32 W-1987 W-2251 W-2194
Textularia mississippiensis Cushman X
Robulus cultrata d'Orbigny X
Robulus gutticostatus d'Orbigny X
Robulus rotulata (Lamarck) d'Orbigny X
Marginulina fragaria (Giimbel) X
Marginulina mexicana Cushman X
Dentalina communis (d'Orbigny) X
Dentalina cocoaensis (Cushman) X
Dentalina jacksonensis (Cushman and
Applin) X
Nodosaria cookei Cushman X
Nodosaria latejugata Giimbel X
Saracinaria italica Defrance X
Guttulina irregularis d'Orbigny X
Nonion umbilicatulum (Montagu) X
Operculinoides antiguensis Vaughan and
Cole X X X
Heterostegina texana Gravell and Hanna X
Bolivina ariana Cole X
Bolivina byramensis Cushman X
Uvigerina gallowayi Cushman X
Eponides mariannensis (Cushman) X
Siphonina advena Cushman X
Cibicides lobatulus (Walker and Jacob) X
Cibicides pseudoungeriana (Cushman) X
Lepidocyclina (Lepidocyclina) asterodisca
Nuttall X
Lepidocyclina (Lepidocyclina) parvula
Cushman X X X X
Lepidocyclina (Eulepidina) undosa
Cushman X X X X

Local Details.-Exposures of Suwannee limestone in Jackson
County are not abundant. The formation is overlain unconform-
ably in much of the county by sandy clays, clays, and marls which
are considered to be lower Miocene in age. An almost continuous
section of the Suwannee limestone is exposed along the Chipola
River south of Marianna.

Oligocene beds are exposed along Rhabb's valley southeast of
Cottondale. Small outcrops are to be found at scattered points south
of a line through Marianna and Cottondale and north of Dry Creek.
In the southeastern part of the county, terrace deposits and the
Tampa formation appear to overlap completely the Suwannee lime-
stone.

At the following localities exposures of the Suwannee limestone
may be seen:

FLORIDA GEOLOGICAL SURVEY

Loc. J-3. A road cut on highway Fla. 73 in the SE 1/ SW 1/4
sec. 30, T. 5 N., R. 10 W., exposes three feet of brownish-gray,
clayey Suwannee limestone with molds of Lepidocyclina sp. and
Pecten sp. below two feet of gray limestone. The elevation of the
top of the limestone is 143 feet.

Suwannee limestone is exposed southward along the Chipola
River between localities J-25 and J-57 from the SW 1/4 sec. 14, T.
4 N., R. 10 W. to the south side of sec. 6, T. 2 N., R. 9 W. A sink-
hole to an underground stream (loc. J-32) on the east bank of the
Chipola River in the south side SW 1/4 NW 1/4 sec. 12, T. 3 N., R.
10 W. contained well preserved echinoids, identified by C. Wythe
Cooke as probably Clypeaster oxybaphon Jackson. Kuphus in-
crassatus was observed in the SE 1/4 NW 1/4 sec. 19, T. 3 N., R. 9
W. (loc. J-46) on the east bank of the river in a hard, crystalline
limestone that extended about five feet above the water. The Su-
wannee limestone beds have a dip of 64 feet per mile (loc. J-51) just
north of the Sink Creek bridge across the Chipola River in the
NE 1/4 SE 1/4 sec. 30, T. 3 N., R. 9 W. (figure 14). Kuphus incrassa-
tus was found in a porous, hardened limestone which extended four
and one-half feet above the water level near the center of the NE
1/4 sec. 31, T. 3 N., R. 9 W. (loc. J-53). Kuphus incrassatus and
Lepidocyclina sp. are to be found on the west bank of the river,
center north side NE 14 NE 14 sec. 6, T. 2 N., R. 9 W., (loc. J-54),
in a tan weathered limestone with drusy cavities and calcite-filled
veins. At a very wide shoal in the river (loc. J-57) at the center of
the south side of the SW 1/ SE 1/4. sec. 6, T. 2 N., R. 9 W. hard, dense
to porous, tan limestone containing Kuphus incrassatus and other
mollusks is exposed. Unquestioned Tampa limestone was found 1/8
of a mile downstream from this point.
Just north of Marianna, along a graded road that joins Fla.
Highway 167 just west of the Chipola River (loc. J-98, J-99, J-102),
greenish bentonitic clays overlie the lowermost bed of the Suwannee
limestone in the road bed. J-98 is located in the NW corner sec. 34,
T. 5 N., R. 10 W.; J-99, at the entrance to an abandoned CCC camp,
SE corner NW 14 NW 1/4 sec. 34, T. 5 N., R. 10 W.; and J-102 SW
1/4 SE 1/ sec. 28, T. 5 N., R. 10 W.
Loc. J-177. A sinkhole in the NE 1/4 SW 1/4 sec. 12, T. 4 N., R.
9 W., just north of the highway (Blue Springs detour) exposes
about 25 feet of Suwannee limestone which is covered by terrace
sands and gravel. The elevation of the land surface around the
sink is 122 feet. Just east of the limestone sink there is a 20 foot

GEOLOGY OF JACKSON COUNTY, FLORIDA

sinkhole in which only terrace sands and gravels were observed
when it was visited in 1948.
Loc. J-166. Residual boulders of Suwannee limestone are found
in the woods east of the road in the northwest corner of the NE 1/4
sec. 3, T. 6 N., R. 8 W. The elevation of the land surface is 121 feet.
Loc. J-175. At a roadside exposure, NE 1/4 NE 1/4 sec. 29, T. 5
N., R. 11 W. about 5 feet of Suwannee limestone, similar to that
at J-13, is weathering to a greenish-brown sticky clay. The elevation
at the top of the Suwannee limestone is 163 feet. Overlying this
limestone and extending to the top of the hill (elevation 185 feet)
are greenish white clays that appear to be the same as those clays
assigned to the Tampa formation in the southern part of the
county. This is the best exposure in central Jackson County of
the clays that overlie the Suwannee limestone.
Loc. J-182. A residual boulder or a pinnacle of Suwannee lime-
stone in which Lepidocyclina sp. was observed is exposed on the
north side of the hill in a roadside ditch near the NW corner NE 1/4
NE 14 sec. 7, T. 4 N., R. 11 W. The elevation of this locality is
estimated to be not greater than 150 feet and this appears to be
the top of the Suwannee limestone in western Jackson County.
Neither residual boulders nor bedrock outcrops that could be re-
ferred to the Suwannee limestone were found in southwestern
Jackson County at elevations above the contact as shown in the
structure section, Plate V.
Loc. J-171. A sinkhole in the woods west of the road in the NW
1/ SW 1/ sec. 28, T. 4 N., R. 11 W. exposes about 5 feet of tan
Suwannee limestone overlain by sandy clays and clay. The eleva-
tion of the top of the limestone is 106 feet. This is one of the best
exposures of the Suwannee limestone in the southwest part of the
county. The clays overlying the Suwannee limestone are believed
to belong to the Tampa formation.
Loc. J-165. At a roadside outcrop, located near the center of the
N 1/2 NW 1/4 sec. 22, T. 4 N., R. 11 W. at the east side of Rhabb's
Valley on Fla. Highway 276, there is exposed, at an elevation of
93 feet, a small patch of tan, clayey marl, overlying chalky white
Marianna limestone, which appears to be lowermost Suwannee.
The clayey marl, of Suwannee age, is similar to that exposed in
the upper bed at loc. J-13.
Loc. J-192. A sinkhole in the woods south of Fla. Highway 276
in the NW 14 SE 1/ sec. 13, T. 4 N., R. 11 W. exposes about 20

FLORIDA GEOLOGICAL SURVEY

feet of tan, clayey, dolomitic limestone. The elevation of the top
of this Suwannee limestone section is 110 feet.
The Suwannee limestone was encountered in the following wells:
W-l, W-4, W-7, W-547, W-276, W-1356, W-1357, W-1358, W-1359,
W-1362, W-1364, W-1478, W-1479, W-1783, W-1793, W-1794,
W-1824, W-1873, W-1987, W-2194, W-2251, W-2260, W-2328,
W-2329, and W-2409. Appendix I gives the depth at which the
formation was encountered.

MIOCENE SERIES
TAMPA FORMATION
Historical.-For a historical summary of the Tampa formation
the reader is directed to Florida Geological Survey Bulletins 21
and 29. Since this formation is primarily clay and clayey marls
in Jackson County, the term Tampa formation will be used in this
report, but stratigraphically the unit is the same as the Tampa
limestone defined by Cooke and Mansfield (1936, p. 71). In the
southwestern part of Jackson County, beds that may belong to
younger formations have been included in the Tampa formation
but these beds lie at elevations that are higher than those expected
for the Tampa formation. No fossils were found in these beds, and
lithologically they are similar to the Tampa formation.

Definition.-The Tampa formation of this report consists of
white, gray, and green clays that are frequently calcareous, and, in
the southeastern part of the county, white, arenaceous and argil-
laceous limestone. The Tampa formation is overlain by the clayey
sands and gravels of the terrace deposits and underlain by the
buff to tan limestones and dolomitic limestones of the Suwannee
limestone.

Lithology.-The Tampa formation is more calcareous in the
southeastern part of the county and along the Chipola River, and
it is more argillaceous in the western and northwestern parts of
the county. The whole formation is characterized by the presence
of fine, scattered quartz grains. The gray and white clays and argil-
laceous limestones commonly have, in addition to the fine sand,
scattered pellets of green clay similar to that which occurs in the
beds within the formation as exposed above Jim Woodruff Dam
near Chattahoochee.

Thickness and Structure.-The Tampa formation at the Jim
Woodruff Dam is 170 feet thick; at Sink Creek it is no more than

GEOLOGY OF JACKSON COUNTY, FLORIDA

100 feet thick; and in the southwestern part of the county near
Round Lake it is about 70 feet thick (figure 16). Figure 17 shows
the configuration of the top of the Tampa formation as reconstruc-
ted from wells and outcrops.

Paleontology.-With the exception of a few calcareous zones,
the Tampa formation as exposed in Jackson County is not very fos-
siliferous. No fossils were found in any of the clays although at
some localities small fossiliferous boulders of silicified clay, or clay
in which secondary calcification had occurred, were found. These
fossils, or their prints, are poorly preserved.
Reference should be made to Mansfield's report (1937, pp. 31-33)
for lists of fossils from four fossiliferous zones in a section exposed
along the road at the east end of Victory Bridge on Highway U. S.
90 in Gadsden County.

Local Details.-The Tampa formation crops out in the southern
part of Jackson County (Plate I) and thick sections occur in both
the southeastern and the southwestern portions of the county. Be-
cause it is predominately clay, the parts of the county underlain by
the Tampa formation have more relief than the areas of the county
underlain by purer limestone. These clays are quite blocky and
tough and are effectively eroded only by stream abrasion.
The course of Dry Creek is controlled by the southward dip of
the Tampa beds and of the underlying Suwannee limestone. The
escarpment south of Dry Creek is a result of the lateral erosion by
this subsequent stream over a long period of time (Plate II). Simi-
larly, both the Flint River and the Apalachicola River are bordered
to the southeast in this general area by a high escarpment that
has resulted from the lateral erosion of these streams down the
regional dip.
The following significant localities show typical expressions of
the Tampa formation in Jackson County:
The most complete Miocene section exposed in the Jackson
County area is to be found along the access road at the east end of
the Jim Woodruff dam, in Georgia, on the Apalachicola River. The
top of the Tampa formation at this locality has an elevation of
169 feet. Mansfield (1937, p. 32) gives an elevation of 165 feet for
station 13854, bed 12 (W. C. Mansfield and F. S. MacNeil), of the
section exposed about one mile south of the Jim Woodruff Dam
along the road at the east end of Victory Bridge in Gadsden County.

PROBABLE THICKNESS
OF THE
TAMPA FORMATION
--0- THICKNESS IN FEET
iJmUL LIMIT OF WOTROP
o WELL SAMPLE
X SURFACE OUTCROP
PROBABLE PRE TAMPA POST SUWANNEE FAULT

SCALE
4 0 4 8 IlMIt

tR I W | R JI w R w pr II 0 I 2 A n I R f W m i

Figure 16.-Map, probable thickness Tampa formation.

0 5 IAL 4 W I ft 3

STRUCTURE MAP
JACKSON OF THE
OF THE
STAMPA FORMATION
S-Conrour datum mean sea lrvel
T '.--50- CONTOWR

0 WELL SAMPLE
-- -4 8 SURFACE OUTCROP
S. __ PROBABLE PRE TAMPA POST SUWANNEE FAULT
W '2252 SCALE
I W- . /W1364 4 06

S251

T i~. i ~ ------ ----- ----- --- ^I ^ r
2z

WASHINGTON o-" "- --.

SBAY CALHOUN
LIBERTY
C

S I R 13 2 2 R I I W I 9 w I I 4 A e W

Figure 17.-Structure map of Tampa formation.

FLORIDA GEOLOGICAL SURVEY

Figure 18 shows the upper part of the section at the east end of
the Jim Woodruff Dam, and figure 19 is a composite section of the
Tampa formation at the east end of the dam. This section was
partially measured when, unfortunately, the excavation in the
floodplain of the river was filled before precise levels and collections
could be made. The elevations from 122 feet to the top of the Tampa
formation section, however, were surveyed with a level and rep-
resent true elevations above sea level. The elevation of 40 feet
shown in figure 19 is also a true elevation obtained from the U. S.
Engineers at the dam, and represents the elevation of one of their
stations in bedrock at the bottom of the foundation cut in the flood-
plain. Several "cuts" of cores from U. S. Engineer core holes at
the dam are on file with the Florida Geological Survey, and eleva-
tions for these core holes are available there.
The white argillaceous limestone exposed in both the Jim Wood-
ruff Dam section and the Old Chattahoochee Landing section at
the east end of Victory Bridge contains fine, scattered quartz sand.
The section at the dam exposes four beds of green clay along the
access road. The lowest of these clays appears to have been de-
posited over the mudcracked surface of the underlying argillaceous
limestone (elevation 135 feet). Two additional green clays were

Figure 18.-Upper part of Tampa formation as exposed at east end of
Jim Woodruff Dam on Appalachicola River, just north of Chattahoochee, in
Decatur County, Georgia.

GEOLOGY OF JACKSON COUNTY, FLORIDA

exposed in the dam foundation excavation below elevation 122 feet
and above elevation 40 feet in about the position shown in figure 19.

Elev.
169'- Unconformity
Grey to brown sandy is., thin cprbonnceous clays at top.
Massive chalky Is., thin bedded at top with some green
clay seams and lenses.
150' White ls., fossiliferous lenses, green and clayey at top.
146' Soft clay, lower part fossiliferous.
19, Thin green bed at base, white marl at ton.
139'- Chalky, sandy, vesicular la.
135' Green clay with fish bones and manatee rib at base.

White, fossiliferous, chalky limestone, upper surface
122' I mud cracked.

Light grey to white clayey, finely sandy marl.

Olive green plastic clay.

Soft, tan to white clayey marl.

-Fossiliferous zone.

S 2 foot bed of green clay

I I Fossiliferous zone.

40'- Base of Trench

I Kuphus incrassatus, top of Suwannee Is?

Figure 19.-Composite section of the Tampa formation at east end of Jim
Woodruff Dam. Elevations at 0 feet, 40 feet, and above 122 feet are accurate.
Elevations shown to the left were determined by levelling.

FLORIDA GEOLOGICAL SURVEY

Loc. J-137. An outcrop at the Tee road intersection in the center
of the NW 1/ sec. 20, T. 4 N., R. 7 W. exposes about 10 feet of white,
siliceous clay. The elevation at the top of these siliceous boulders
is 175 feet.

Loc. J-66. A roadcut near NW corner SE 1/ NW 1/ sec. 30, T.
4 N., R. 7 W. exposes 63 feet of tough stickey, gray clay and marl
that extends almost to the top of a hill which has an elevation of
238 feet. At this locality the clay tends to weather to cherty nodules
and at locality J-67, the crossroads at the center of the north side
NW 1/4 sec. 31, T. 4 N., R. 7 W., at an elevation of 197 feet, a similar
deposit was found.

Loc. J-65, a small waterfall, on a creek near a flooded sinkhole
(Falling Branch Sink) is situated near the center of sec. 30, T.
4 N., R. 7 W. and exposes a tan to white sandy limestone.

Loc. J-112, a roadside outcrop, just north of the railroad crossing
at the approximate center of sec. 36, T. 4 N., R. 7 W. exposes about
5 feet of white fossiliferous Tampa limestone. The elevation at the
top of the limestone is 135 feet.

Loc. J-64, a roadside outcrop, located 2.8 miles south of Sneads
near the center of sec. 9, T. 3 N., R. 7 W. exposes about 5 feet of
pinnacled, sandy, chalky, white Tampa limestone which is overlain
by terrace deposits. The elevation of the top of the limestone at
this exposure is 140 feet.

Loc. J-69, a creek bank, east of the road in the SE 1/ NW 1/
sec. 16, T. 3 N., R. 7 W. exposes 9 feet of greenish clay that grades
upward into a creamy, white marl. The elevation at the top of
the marl is 143 feet.
Loc. J-70, a creek bank, on the east side of the road, NW 1/4
SW 1/4 sec. 16, T. 3 N., R. 7 W. exposes 10 feet of white argillaceous
limestone overlain by a greenish clay. The elevation at the top of
the green clay is 131 feet.
Loc. J-71, a roadside ditch, at about the center of NW 1/4 sec.
21, T. 3 N., R. 7 W. exposes a similar white, clayey, sandy lime-
stone. The elevation of the road at this locality is 133 feet.
Loc. J-111, an outcrop at the south end of Ocheesee Pond at
about the center of the S 1/2 sec. 18, T. 3 N., R. 7 W., exposes 5 feet
of soft, white, sandy marl. The elevation at the top of the marl
is 134 feet.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Loc. J-133, a road cut in Calhoun County, NW 1/4 NE 1/4 sec. 6,
T. 2 N., R. 7 W., exposes white, soft chalky Tampa formation over-
lain by about 5 feet of green clay. The elevation at the top of the
white limestone is 97 feet. The white limestone and green clays
are overlain by terrace sands and gravel.
Loc. J-187, a roadside exposure at the top of a hill on the graded
road near the center of the south section line sec. 18, T. 4 N., R.
8 W., exposes Tampa type clay. The elevation of the road at the
top of the hill is about 150 feet. A series of ponds just west of the
road along a line trending northeast probably marks the Oligocene-
Miocene contact.
Loc. J-140, a sinkhole in the woods at the approximate center of
sec. 21, T. 4 N., R. 8 W., exposes 5 or 6 feet of white, clayey limestone
with greenish clay-ball inclusions which are similar to those at
the Jim Woodruff Dam section near Chattahoochee. The elevation
of the top of the limestone at this sinkhole is 157 feet.
Loc. J-82, a limestone pinnacle at the north edge of the highway
(Blue Springs detour) in the SW 1/4 NE 1/4 sec. 21, T. 4 N., R. 8 W.,
exposes white, hard Tampa limestone overlain by greenish clay. The
elevation at the top of the limestone is 108 feet.
Loc. J-114, the side of a hill around a sink near Shady Grove, at
the approximate center sec. 14, T. 3 N., R. 8 W., exposes small
patches of tan, clayey Tampa limestone and gray clay.
Loc. J-115, a sinkhole at the site of an old grist mill in the NW
1/4 NW 1/ sec. 25, T. 3 N., R. 8 W., exposes 12 feet of Tampa lime-
stone. The elevation at the top of the limestone is 144 feet. This
is a good exposure and the softer, white limestone is rather fossili-
ferous. No road extends to this locality and it is best to inquire for
local directions to the site of the old grist mill.
Loc. J-129, a wagon road and sink hole in the approximate center
of the N 1/2 sec. 27, T. 3 N., R. 8 W. exposes about 14 feet of marl
of the Tampa formation. The elevation of the top of the marl is
136 feet.
Loc. J-131, the creek bed under a bridge in the NW corner NE 1/4
sec. 32, T. 3 N., R. 8 W., exposes an unfossiliferous, white to cream
colored, clayey limestone.
Loc. J-119, a roadside outcrop in Calhoun County in NE 1/4
NW 1/ sec. 11, T. 2 N., R. 8 W., exposes 10 feet of very clayey, white
marl. The elevation at the top of this marl, which is overlain by

FLORIDA GEOLOGICAL SURVEY

terrace deposit, is 120 feet. The marl weathers to a greenish-brown
clay which cracks and crumbles when dry. This is considered to
represent the upper part of the Tampa formation.
Loc. J-132, a road cut in Calhoun County, just south of the
bridge near the center of the west side sec. 3, T. 2 N., R. 8 W., ex-
poses approximately 8 feet of soft, clayey, sandy limestone overlain
by 2 feet of green, plastic clay. The elevation at the top of the
white limestone is 114 feet. This is considered to be uppermost
Tampa formation. Overlying the green clay of the Tampa forma-
tion are crossbedded sands and gravels of a terrace deposit.
Loc. J-141, a steephead near Alliance, near the center of the S
1/2 NE 1/4 sec. 34, T. 3 N., R. 9 W. just west of the church, exposes
8 feet of gray, sandy clay below about 15 feet of crossbedded sands
and gravel of a terrace deposit. The elevation of the top of this
sandy clay is 180 feet. This steephead is of particular interest since
a spring emerges at the contact between the clay of the Tampa
formation and the overlying sands and gravels. The stream channel
has been cut out of the overlying coarser deposit. This steephead is
developing headward and it has recently cut back across the road
(figure 3).
Loc. J-58, at a boat landing on the west bank of the Chipola
River near the center of the W 1/2 NE 14 sec. 7, T. 2 N., R. 9 W., soft,
white, sandy Tampa limestone is exposed. This limestone crops
out along the river to the south into Calhoun County. The lime-
stone is characterized by fine, scattered quartz grains and varies
from white to light brown in color.
Loc. J-195, a roadside outcrop at the north side of Fla. Highway
276 in the center of the NE 1/, sec. 8, T. 4 N., R. 10 W. exposes 10
feet of very plastic, gray to white, clay at an elevation of 130 feet. A
similar clay that weathers to white chert nodules, typical of clays of
the Tampa, can be seen at the southwest corner of the road inter-
section at SE 1/4 NE 1/4 sec. 13, T. 4 N., R. 11 W. at an elevation of
135 feet. These clays are similar in color, texture, and composition
to the clays of the Tampa formation in the southern part of the
county, and they are here correlated with the Tampa formation. The
clay at J-195 is overlain by bog-iron and terrace deposits ( figure
20).
Loc. J-181, a roadside outcrop on the S side SE 14 SE 14 sec.
15, T. 3 N., R. 10 W., exposes 33 feet of plastic, greenish-gray clay
of the Tampa formation. The elevation at the top of this rather
pure plastic clay is 156 feet.

GEOLOGY OF JACKSON COUNTY, FLORIDA 67

Figure 20.-Locality J-195. Tampa formation clays overlain by "bog iron"
and terrace deposits on highway Fla. 276 east of the Florida Industrial School
for Boys.

Loc. J-159, a cut at a road corner at the SE corner sec. 16, T.
3 N., R. 10 W. exposes approximately 15 feet of rather pure, gray,
plastic, blocky clay. The elevation of the road corner is 147 feet.
This clay is placed in the Tampa formation.

Loc. J-155, a sinkhole just south of W. B. Pumphrey's house
in the center W 1/2 SW 1/ sec. 17, T. 3 N., R. 10 W. exposes 5 feet
of greenish-gray, clayey limestone. The elevation of the top of this
limestone is 144 feet.

Loc. J-90, a sinkhole in the SE 1/ SE 1/ sec. 18, T. 3 N., R. 10
W. exposes 10 feet of sandy, white, glauconitic, argillaceous lime-
stone. The sink is west of the road a short distance.

Loc. J-101, a steephead located near center of the SE 14 sec.
20, T. 3 N., R. 10 W. on the east side of the road exposes what is
probably the uppermost clay of the Tampa formation overlain by
about 30 feet of terrace sands.

Loc. J-95, a roadside outcrop in the center of the W side NE 1/
sec. 22, T. 3 N., R. 10 W. exposes about 10 feet of gray-white marl.
The elevation at the top of this marl is 139 feet.

FLORIDA GEOLOGICAL SURVEY

Loc. J-96. Residual boulders at the top of the hill in the woods
west of highway Fla. 73 in the center of N 1/2 SE 1/4 sec. 23, T. 3 N.,
R. 10 W. range from dense and crystalline to soft, porous, white,
sandy limestone. The elevation at the top of the hill is 132 feet.
While badly weathered, these boulders are very fossiliferous.
Loc. J-153, a steephead east of the road at the center of the W
side NE 1/ sec. 27, T. 3 N., R. 10 W., exposes, at an elevation of 225
feet, about 3 feet of tan, sandy clay of the Tampa formation which
is overlain by 50 feet of terrace sands. This is almost certainly
near the top of the Miocene section in Jackson County and this
clay is referred to the Tampa formation, but it is possible that a
portion of it is Alum Bluff in age.
Loc. J-176, a roadside outcrop near the SE corner NW 1/4 sec.
28, T. 5 N., R. 11 W. exposes about 8 to 10 feet of white, blocky,
sandy clay and clay. The elevation of the top of the clay is 155
feet. This locality is referred to the Tampa formation because the
clays are similar to clays in the southern part of the county that
were referred to the Tampa formation. A similar white clay over-
lies the Suwannee limestone at locality J-175 farther west on this
same road.
Loc. J-93. Residual boulders of the Tampa formation occur along
the road and extend to the top of the hill south of the road NW 1/
SE 1/ sec. 7, T. 3 N., R. 11 W. The elevation of the road where
this float is first observed is 143 feet. The elevation at the top of
the hill south of the road is about 175 feet. The top of this hill
appears to have been leveled by terrace development.
Loc. J-92. At the bottom of a sink hole in the SW 1/ NW 1/
sec. 13, T. 3 N., R. 11W., a small patch of soft, white, argillaceous
Tampa limestone is exposed. This sink is about 100 yards north
of the road and the land surface has an approximate elevation of
110 feet.
Loc. J-160, a road cut at the NW corner SW 1/4 sec. 14, T. 3 N.,
R. 11 W., exposes fossiliferous boulders or pinnacles of tan to white
clayey marl. The elevation of the road corner is 150 feet. The
marl is overlain by terrace gravels and sands in which the bedding
is confused by slump. This outcrop may consist only of residual
boulders which represent higher beds. The fossils are poorly pre-
served as external molds.
Loc. J-163, a sinkhole in about the NW 1/4 NW 14 sec. 16, T. 3 N.,
R. 11 W., exposes silicified fossiliferous boulders of the Tampa

GEOLOGY OF JACKSON COUNTY, FLORIDA

formation in rather pure, plastic clay. The elevation of the highest
silicified limestone boulder is 171 feet. Only boulders could be found
in the soil around this sink and it is probable that they represent
silicified zones in the clayey limestone. Augerholes at this locality,
located to one side of the sink and carried below the level of the
boulders, failed to encounter a rock zone, but the clay analysis of
the augerhole samples (Appendix II, loc. J-163) indicated a limey
zone at a depth of 6-7 feet.
Loc. J-188. Boulders of limestone in the field near the center of
the west line NW 1/ sec. 18, T. 3 N., R. 11 W. show occasional faint
mollusk imprints. The elevation of this field is 177 feet.
Loc. J-164. A field outcrop underneath the REA power line on
the A. C. Siefert farm at the SW corner NW 1/4 sec. 35, T. 4 N., R.
12 W. exposes very hard recrystallized limestone at an elevation of
171 feet. Archaias? sp. was noted in this rock and it is referred
to the Tampa formation.
Loc. J-87, a railroad cut at the north edge of Round Lake in the
NE 1/ SW 1/4 sec. 13, T. 3 N., R. 12 W., exposes a clay section which
is assigned to the Tampa formation. The elevation at the top of
this section, 265 feet, seems to be too high for the Tampa formation
when compared with that of other exposures, and this clay section
may represent the Alum Bluff group, or possibly younger Miocene
formations. These unfossiliferous clay beds have been folded,
probably because of subsidence, the result of solution of the under-
lying limestone (figure 21).
The Tampa formation was encountered in the following wells:
W-l, W-4, W-7, W-547, W-276, W-1478, W-1788, W-1796, W-1813,
W-1824, W-1834?, W-1872, W-1874, W-2194, W-2251?, W-2260,
W-2409, W-2433, and W-2531. Appendix I gives the depth at which
the formation was encountered.

POST-MIOCENE DEPOSITS

Historical.-The complicated history of the terminology ap-
plied to the post-Miocene deposits of Florida is adequately reported
in Florida Geological Survey Bulletins 21 and 29 and need not be
repeated here.

General Discussion.-Vernon (1951) suggests that the deposits
underlying each terrace surface be given a formational name the
same as that of the associated terrace. Because of the difficulty of

FLORIDA GEOLOGICAL SURVEY

Figure 21.-Locality J-87. Railroad cut at Round Lake showing Miocene?
clays (Alum Bluff?) overlain by terrace deposits.

dating these deposits in any other way, this seems to be the most
satisfactory system. The terrace deposits underlying the terrace
surfaces are therefore named as follows:

Terrace Surface underlain by Terrace Deposit
Pamlico Pamlico fm.
Wicomico Wicomico fm.
Okefenokee Okefenokee fm.
Coharie Coharie fm.
Cooke (1945) referred the deposits underlying what is here
called the Delta Plain Highlands to the Citronelle formation of Plio-
cene age. Because it is not feasible to rule out an early Pleistocene
age for at least a part of these deposits, no definite age is assigned
to these deposits and they are merely considered to be Pliocene? or
Pleistocene in age (Vernon, 1942, p. 134; 1951, p. 15).
It seems agreed that the highest of these post-Miocene terrace
deposits are the oldest and that the lowest are youngest. Further, in
recent years it seems to be agreed that some, if not all, of the ter-
races lying below the Delta Plain Highland surface are related to
sea level fluctuations of the Pleistocene.
Plate II shows the extent of the various terrace surfaces and
post-Miocene deposits as they occur in Jackson County. The sur-

GEOLOGY OF JACKSON COUNTY, FLORIDA

faces are made irregular by dissection, and when topographic maps
become available for the area, it will be possible to add considerable
detail to the map.

Lithology and Thickness.-The terrace deposits consist of clayey
sands, sands, and gravels that change laterally and vertically within
short distances. Most deposits are cross-bedded. Locally, "limonite"
cements the sands and gravels into a hard, dense, ferruginous sand-
stone.
The stream terrace deposits range in thickness from 30 to 50
feet, but the thickness of deposits of the so-called Citronelle forma-
tion is unknown. It is estimated to be approximately 80 feet thick
in southwestern Jackson County.

Residual Boulders.-The stream terrace deposits have fre-
quently incorporated residual boulders of formations that are strati-
graphically higher than those now cropping out at the surface. The
Suwannee limestone in particular has contributed such boulders to
the terrace deposits. A drainage canal that crosses highway Fla.
71, 1.1 miles south of Malone, exposes these boulders incorporated
in the sands and gravels of the Pamlico formation (figures 22 and
23). Vernon (1942, pp. 130-131) described how these boulders
may be let down by erosion and undercutting during periods of
valley cutting so that they slumped down valley walls and thus be-
came incorporated in the terrace deposits. Cooke (1923, p. 4)
considered many of these larger boulders to be in place and mapped
them as Glendon limestone, and he later (Cooke, 1935, pp. 1170-
1171) applied the name Flint River formation to deposits in Georgia
which he considered to extend into Jackson County (Cooke, 1945,
Plate 1). MacNeil (1946) shows how these residual boulders are
incorporated into the terrace, which he shows on the map as resi-
duum.

SEDIMENTATION, BIOFACIES, AND STRUCTURE

The distribution of two distinct biofacies of Jackson Eocene
age is related to the present structure of the Jackson County area.
These two biofacies are interpreted as indications that the present
structural pattern in Jackson County was in existence, or was de-
veloping, as early as Jackson time. The absence of the upper Clai-
borne and the Moodys Branch formations in Jackson County appear
to indicate that the structural pattern was established at least as
early as the beginning of Jackson time.

72 FLORIDA GEOLOGICAL SURVEY

.. -. :.Ih .

Figure 22.-Drainage canal south of Malone cut in terrace deposits.
Looking west from highway Fla. 71.

Figure 23.-Residual boulders of Suwannee limestone in terrace deposits
forming the sides of the drainage canal south of Malone.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Biofacies Evidence.-Lowman (1949, pp. 1950-1964), in a dis-
cussion of the distribution of Foraminifera in Recent sediments of
the Gulf of Mexico, reported that the family Buliminidae, especially
the genera Uvigerina and Bolivina, were dominant in waters of the
inner bathyal zone and that conspicuous numbers and varieties of
the Lagenidae were characteristic of the outer neritic zone. He
placed the boundary between the neritic and bathyal zones at a
water depth of 600 feet.

During the study of the Ocala group in Jackson County, only
the fauna characterized by the genera Asterocyclina, Lepidocyclina,
Operculina, and Operculinoides was encountered until the samples
from well W-1987 were examined. The strata in this well, although
containing a few specimens of Asterocyclina and Lepidocyclina,
were characterized by many specimens of Uvigerina, Bolivina, Rob-
ulus, Marginulina, and Nodosaria. The abundance of species of small
Foraminifera, the rarity of the orbitoidal and camerinid Foramini-
fera, and the generic composition of the fauna is unlike that which
occurs in most exposures of beds of the Jackson stage throughout
Florida. A similar Ocala group fauna that contained no large Fora-
minifera was described by Cole (1944) from cuttings of the city
of Quincy, Gadsden County, water well, W-4. Published faunal lists
for Ocala group localities near Whatley and Grove Hill, Clarke
County, Alabama (Cushman, 1935, localities 1/38 and 7159, p. 4)
contain a fauna characterized by Uvigerina spp., Bolivina spp., and
several genera and species from the family Lagenidae.
Faunas characterized by the Buliminidae and the Lagenidae
occur in scattered areas and are not distributed generally. Further,
this fauna is found only in districts which appear to be structurally
"low." In Jackson County the fauna characterized by Lepidocyclina,
Asterocyclina, Operculina, and Operculinoides occurs only in areas
which are structurally high.

Because the distribution of these two different faunas in the
Jackson County area appears to be related to the structure, the
possibility exists that the structural highs and lows were in exis-
tence, or were developing, when the Ocala group of limestones was
being deposited, and that the distribution of these faunas was con-
trolled by the depths of the water.

Lowman (1949) Phleger (1951), and others have published
studies of foraminiferal distribution in Recent sediments from the
Gulf of Mexico. Lowman (1949), Bandy (1953) and others have

FLORIDA GEOLOGICAL SURVEY

graphically shown for each genus or species its percentage of the
total population at various depths. A comparison between Eocene
species and Recent species, with regard to depth ranges, is not pos-
sible, of course, and a comparison of the relative distribution of
Eocene and Recent genera might be open to serious question. The
following comparisons between Eocene and Recent foraminiferal
distribution are made at the family taxonomic level because it is
believed that the minimum changes in environmental habit and in
relative abundance are to be expected at this taxinomic level.
Further research in the ecology of the Foraminifera may indicate
that comparisons may be made over the Eocene-Recent time span
between more refined taxonomic groups. For the purposes of this
report, comparisons at the family level are adequate to define the
significance of the two biofacies.
Two samples from the uppermost part of the Ocala group in
Jackson County were selected for a comparison of their foramini-
feral content. The shallower water biofacies of the Crystal River
formation is represented by a sample from the Bumpnose member
of the Crystal River formation at locality J-5. The deeper water bio-
facies of the Gadsden limestone is represented by the sample from
288-298 feet of well W-1987. These two samples are from the same
stratigraphic horizon. The percentages shown in figure 24 are
based upon 236 specimens picked from well W-1987, depth 288-298,
and 328 specimens from locality J-5. Specimens of the "large"
Foraminifera were not picked for this comparison but they are rare
in well W-1987 and abundant at locality J-5, where they often con-
stitute over 90 percent of the total volume of the rock.
The Lagenidae constituted 22.45 percent and the Buliminidae
constituted 27.45 percent of the total specimens in the sample from
well W-1987. By contrast, the Lagenidae constituted only 18.2
percent and the Buliminidae constituted only 10.1 percent of the
specimens from locality J-5., which is structurally higher than well
W-1987. Samples from the City of Quincy well W-4 were not
counted for percentages, but the fauna is similar to that of well
W-1987 except that there are no "large" Foraminifera in well W-4.
The "large" Foraminifera are always more abundant in the samples
with lower percentages of the Lagenidae and Buliminidae, and as
the latter increase in percentage of the total fauna, the "large"
Foraminifera become more scarce. The Lagenidae and Buliminidae
become more frequent downdip to the southeast, and beyond the
Cypress fault they become the dominant elements of the fauna.
Southeast of the Cypress fault the Lagenidae and Buliminidae

Well W-1987 (288-298') upper Gadsden limestone
Family
Polymorphinidoe
Planorbulinidoe
Textuloridoe
Vern eui/nidoe
Valvulinidae
Globigerinidae N
Ro to liidoe
Lagenidoe
Anomaloni/doe
Buliminidoe
Misc.

40%

30%

2

10%

Locality J-5, Bumpnose member
Family
Polymorphinidae
222a Plonorbuini/doe
Textuloridoe
A Ve rneuilinidoe
S/ Vo/vulinidoe
7 Globigerinidoe
//1 Roto//idae
/////////////////// Lagenidoe
2 Anoma/inidoe
/II Buliminidoe
/ //7Misc.
Mostly poorly preserved Anomalinidae or Rotaliidae
10% 20% 30% 40%

Figure .A comparison of the
the upper Gadsden

Foraminiferal Faunas of the Bumpnose limestone member and
limestone. "Large" Forominifera omitted.

I m I I

3

FLORIDA GEOLOGICAL SURVEY

dominate the fauna to lower and lower stratigraphic levels until
at Quincy the entire Jackson Eocene section is dominated by them
and there are no specimens of Lepidocyclina, Asterocyclina, and
Operculinoides to be found.
The Jackson stage foraminiferal fauna of well W-1987 is in-
terpreted as an outer neritic or inner bathyal fauna as these zones
were defined by Lowman (1949, pp. 1950-1964). A comparison of
the data discussed above with Phleger's foraminiferal distribution
charts (Phleger, 1951, tables 10-30) suggests that the sample from
locality J-5 would indicate a water depth of roughly 150-160 feet
at the time of deposition. The same comparison suggests that the
depth of the water at the time of deposition for the sample from
well W-1987 was about 250-260 feet. These are interpreted as mini-
mum depths. The sample from well W-1987 is structurally 331 feet
lower than locality J-5 at the present time. At least 150 feet of the
present structural interval between the two localities can be re-
moved, because of post-Jackson structural movements, mainly the
displacement caused by the Cypress fault, so that a depositional
difference in depth of 181 feet, as a maximum, existed when the
sediments were deposited.
It should be understood that no specific depths in feet are being
formally proposed for the Eocene faunas discussed above, but it
seems that the depth zones mentioned above are reasonable. It is
my opinion that the faunas dominated by the Lagenidae and the
Buliminidae are deeper water faunas than those in which the
Orbitoididae and Camerinidae dominate and in which the Bulimin-
idae in particular are not dominant. Exact depth correlations be-
tween Eocene and Recent faunas cannot be made because different
species are involved. Similarly, exact depth comparisons cannot be
made between Eocene and Recent faunas based upon their generic
frequencies with certainty because of moderate shifts in the generic
frequency composition of faunas during that time interval. It is
probable, however, that relative abundance of most families is
much the same for a given environment today as it was in the
Eocene. Certainly, families should change their overall environ-
ment requirements slower than lower taxonomic units.

The important point is that the water was appreciably deeper
southeast of the Cypress fault than to the northwest during latest
Jackson times. This indicates that the present regional structural
pattern was established as early as Jackson time. The absence of
the upper part of the Claiborne Eocene and the lower Jackson

GEOLOGY OF JACKSON COUNTY, FLORIDA

Eocene in the Jackson County area is more plausible when it is
understood that the present structural pattern was in existence
then. Therefore, it is not too surprising that movement along the
Cypress fault occurred along a zone of flexure after the deposition
of the Suwannee limestone of late Oligocene age, and before, or
during, the first phases of deposition of the Tampa formation of
early Miocene age. All of this indicates structural continuity, re-
flected in both the sediments and the faunas, that began at least as
early as the Jacksonian and which has not been destroyed or ap-
preciably modified. Exactly how early this structural pattern origi-
nated is not known. More deep wells between Jackson County and
Tallahassee must be drilled before sufficient data will be available
to determine when this structural pattern originated. Plate IV
shows diagramatically the faunal relationships to the structure in
the area just discussed.

General.-In considering the Tertiary geological history of this
area, the following features are important:
1. A structural high exists in north central Jackson County, in
Holmes County, and northern Washington county (figure 6).
The Oligocene-Miocene contact is an unconformity in the central
part of Jackson County; the contact becomes more nearly conform-
able to the south and southeast (plate III).
2. Deep water foraminiferal faunas are found in structural
lows northwest, northeast, southeast, and south of the structurally
high area.
Deep water upper Jackson foraminiferal faunas are found in
Clarke County, Alabama (Cushman, 1935, facing p. 60, no. 3),
Jenkins County, Georgia (Cushman, 1935, facing p. 60, no. 2),
Gadsden County (Cole, 1944) and southeastern Jackson County in
Florida. These areas are structurally low.
3. The Tertiary sediments thicken toward the southeast and
south away from the structural high (figure 25).
The Suwannee limestone thickens considerably southward from
Jackson County (Plate III).
4. The Bumpnose fauna appears in an area around and to the
north of Marianna and in an area about Tallahassee and probably
extending as far east as Suwannee County. These areas are struc-
turally relatively high and the fauna indicates shallow water (Plate
IV).

ISOPAGHOUS MAP 0
OF THE
UPPER EOCENE, OLIGOCENE
AND
LOWER MIOCENE FORMATIONS
-600- THICKNESS IN FEET DOTTED WHERE UNCERTAIN
-AA"A LIMIT OF OUTCROP
O WELL SAMPLE
X SURFACE OUTCROP
PROBABLE PRE-TAMPA POST SUWANNEE FAULT

SCALE

0 4 I4 t2AMAs

0

U / o

// 0

GADSEN

Figure 25.-Isopach map of the upper Eocene, Oligocene, and lower Miocene formations.

GEOLOGY OF JACKSON COUNTY, FLORIDA

5. Beginning with the Miocene, the sediments in Jackson County
become more elastic to the west and northwest away from the
structural low in Gadsden and Leon Counties.

Crystal River formation.-The uniform thickness of the Crystal
River formation in Washington, Holmes, and Jackson Counties in-
dicates that uniform conditions of deposition prevailed. In wells
W-4 and W-1987, however, the upper part of the Jacksonian section
has fewer large Foraminifera than usual. Small Foraminifera,
however, are abundant in samples from these wells. In well W-1987
the families Buliminidae and Lagenidae are represented by abun-
dant genera, species, and individuals. Regarding the Ocala section
of well W-4, Cole (1944, p. 16) states:

"Various species of Uvigerina of upper Eocene type were found in
virtually every sample and numbers of these occurred in the last sample
(1370 feet). So easily recognized and typical Jackson species as Buli-
mina jacksonensis Cushman and Hemicristellaria fragaria (Giimbel),
variety texasensis (Cushman and Applin) characterize this section to-
gether with Eponides jacksonensis (Cushman and Applin) and Sipho-
nina jacksoncnsis Cushman and Applin."

Cole (1944, p. 16) also mentioned that large Foraminifera are
not present in the portion of W-4 which he assigned to the Ocala
group,, and, although Ocala group large Foraminifera are present
in W-1987, they are relatively rare. Further, neither of these wells
encountered the Lepidocyclina (Nephrolepidina) chaperi zone.
From Lowman's work, (1949, Table II, p. 1956), based on recent
foraminiferal studies in the Gulf of Mexico, the small Foramini-
fera faunas from wells W-4 and W-1987 indicate deep water, pos-
sibly the outer neritic or inner bathyal zone (figure 24).
Cole (1944, pp. 16-17) was concerned about the apparently ab-
normal thickness (690 feet) of the Ocala group in well W-4, and he
suggested that savings may have obscured a lower unfossiliferous
formation. Applin and Applin (1944, fig. 23, pp. 1736, 1737)
assigned the lower part of what Cole considered to be Ocala in
Well W-4 to the Tallahassee limestone.
That the Marianna-Chipley area was a relatively positive seg-
ment during deposition of the Crystal River formation seems to be
borne out by the faunal distribution (Plates III and IV). In struc-
turally high areas, the Ocala group is characterized by abundant
large Foraminifera. In structurally low areas, small Foraminifera
of deep water types are found. It would appear therefore, that

FLORIDA GEOLOGICAL SURVEY

the present general structural configuration was in existence
during the deposition of the Crystal River limestone, and that there
probably was differential downsinking, Holmes, Jackson, and Wash-
ington Counties sinking less than the structurally low areas to the
east and to the south where the Gadsden limestone was deposited.

Bumpnose Member.-It is suggested that the Bumpnose mem-
ber [Lepidocyclina (Nephrolepidina) chaperi zone] represents a
depositional environment located far from land and shallower than
that of the pre-Bumpnose Crystal River. L. (N.) chaperi was not
transported from some other area by currents, because: a) this
species does not occur at any known horizon except the L. (N.)
chaperi zone; b) where it occurs it does so in great numbers;
c) the fauna of the zone is a peculiar one suggestive of a restricted
facies. It is difficult to account for the absence of the L. (N.) chaperi
zone elsewhere on the basis of erosion because it is absent in those
areas where other formations are most complete and where un-
conformities are fewest and of the least magnitude. L. (N.) chaperi
must be confined to a restricted habitat, apparently shallow water.
At the end of the Eocene, and at the end of the deposition of the
L. (N.) chaperi zone, further shoaling probably occurred to the
extent that there was a period of mild erosion or at least non-depo-
sition. In Jackson County this probably did not proceed far enough
to bring the beds above water.
Marianna Limestone.-Renewed downsinking initiated deposi-
tion of the Marianna limestone in moderately shallow water. The
very fine chalky nature of the Marianna limestone in Jackson County
suggests that chemical precipitation was important in its formation.
Toward the end of the deposition of the Marianna limestone,
shoal conditions began to prevail once more. This brought to an end
the quiet, even deposition of the massive Marianna limestone, and
subaqueous scour and reworking occurred locally. The upper
portion of the section exposed at J-13 is indicative of this (figure
12).
Suwannee Limestone.-With the return to shallower conditions
Lepidocyclina (Eulepidina) spp. appeared with the deposition of
the Suwannee limestone. The trough to the east of Jackson County
may have remained more negative than the Marianna-Chipley area,
for a thicker Oligocene section is found there. This thickening may
be the result of post-Suwannee-pre-Tampa erosion in the Mari-
anna-Chipley area. Throughout the deposition of the Suwannee

GEOLOGY OF JACKSON COUNTY, FLORIDA

limestone the water was shallow. Minor fluctuations about an aver-
age depth produced good bedding and caused faunas to appear, dis-
appear, and reappear at different horizons at any given locality.
This may have resulted in part from structural movements and in
part from variations in the rate of sedimentation. Interbedded
marls, limestones, and sandy limestone suggest the same thing.
Miocene (Tampa).-At the end of the Oligocene, and probably
continuing into the Miocene, renewed uplift and faulting occurred
with the result that the Oligocene sediments were faulted and were
gently arched (plate III; figure 14). The top of this arch was eroded
before Miocene deposition occurred in central Jackson County.
On logs of two core holes at the Jim Woodruff Dam, W-1478,
and W-1479, Vernon expressed the opinion that the Oligocene-
Miocene contact at Chattahoochee was gradational. Along the Chi-
pola River the contact is not clear, but there seems to be no pro-
nounced unconformity. In the central portion of Jackson County
the Miocene beds cut across the bevelled surface of the Suwannee
limestone. The Cypress fault resulted from differential movement
between the positive block to the northwest and the negative block
to the southeast and its position may have been controlled by pre-
vious structure.
From the beginning of Miocene sedimentation to the deposition
of the Plio-Pleistocene formations in Florida, increasingly plastic
deposits were laid down. In going toward the northwest in Jackson
County, Miocene calcareous deposits become progressively scarcer
and clays become commoner. This indicates that the source of sedi-
ments was to the northwest. The depositional area to the east of
Jackson County remained relatively negative and thicker Miocene
deposits accumulated there. Faunas in the Tampa formation are
generally of the inner neritic type and the water at times must
have been very shallow. The green clay at elevation 135 feet at
the east end of the Jim Woodruf Dam on the Apalachicola River
appears to have been deposited over a mud-cracked surface. Tab-
ular flakes and fragments of the underlying white calcareous clay
were deposited in the bottom part of the green clay. Associated with
these flakes are many bone fragments including a manatee rib, fish
vertebrae, and freshwater fish breeding tubercles.3 These beds
represent marginal deposits of a delta which was being extended
into the Gulf of Mexico (Vernon, 1951, p. 184).

3Personal Conversation with Robert Ross and checked with E. C. Raney,
Cornell University, 1950.

FLORIDA GEOLOGICAL SURVEY

Post-Miocene.-Continued deposition extended this delta farther
into the Gulf of Mexico and culminated in deposition of the sands
and sandy clays that form the Delta Plain Highlands. Since that
time uplift, or a lowering of sea level, has raised these areas to
their present height.

Summary.-Central Jackson County has been a relatively posi-
tive area at least since upper Jackson time. Intermittent uplift
and slower sinking of this positive area coupled with dominant
downsinking of the negative area to the east and the south, has
resulted in the development of distinct lithologic and faunal facies.

ECONOMIC GEOLOGY

General.-Limestone, clay, sand, gravel deposits, and ground
water are the mineral resources of Jackson County that have a
proved occurrence in quantities great enough for commercial ex-
ploitation. Water alone is being exploited on a substantial scale.
Limestone is being produced in commercial quantities at only one
quarry, though minor operations for the production of "chimney
rock" occur sporadically. Sand in limited amounts is produced
within the county for use in concrete, but larger operations could
be sustained in the southern part of the county. Clay is being
utilized only in the preparation of roadbeds.

Clay.-The use of clay at the present time is limited to the con-
struction of highway roadbeds. The sandy clay or clayey sands of
the terrace deposits are preferred, because of their good permea-
bility. These sandy clays are generally secured from small borrow
pits.
Certain clays were used in the past for the manufacture of
brick, but no kilns are operating in the county today. Control of
the quality of the finished product was a serious difficulty en-
countered by these early brick manufacturers. Unsatisfactory kilns
and inadequate temperature control primarily were responsible for
the non-uniform product. In general the clays of the terrace de-
posits are most likely to be suitable for the manufacture of common
brick because most are lower in calcium carbonate and are less apt
to bloat during firing. Four clays in Jackson county are known to
be suitable for brick manufacture on the basis of past production
and laboratory tests. These are found at: 1. Locality J-183, 100
yards southwest from the road intersection in sec. 17, T. 4 N., R.
11 W.; 2. A pit on the grounds of the Florida Industrial School for

GEOLOGY OF JACKSON COUNTY, FLORIDA

Boys; 3. The old Blackman clay pit in the SE 14 sec. 6, T. 6 N., R.
12 W.; and 4. Locality J-162 located 100 yards south of the roid
corner in the SW 1/4 SE1/ NW 1/4 sec. 9, T. 3 N., R. 11 W. In Ap-
pendix II test data determined by the Florida Engineering and
Industrial Experiment Station are listed for clays typical of those
found in the county. These clays were selected for testing primarily
with reference to their geological occurrence so that some basis for
further exploration might be available. Test data for clays at lo-
calities J-183 and J-162 are included in Appendix II.

The pit at locality J-183 was operated formerly by Mr. Barbour
of Cottondale to produce clay for the manufacture of brick. The
property, now owned by Mr. J. P. Stanlind, has not been operated
for more than ten years. Brick made from this clay has a very
pleasing gray-white color and good physical properties (Appendix
II). It should also be noted that test data on this clay indicates
that it is suitable for use as a natural art pottery body, for use on
a wheel, and for use as a refractory clay. A brick of similar ap-
pearance was produced a good many years ago at the old Blackman
clay pit located in the SE 1/ sec. 6, T. 6 N., R. 12 W. Both the Bar-
bour and Blackman pits are located on low ground in beds within
the terrace deposits. These deposits of dark colored clay may repre-
sent accumulations in meander loops along the old streams that de-
posited the terrace materials. The altimeter elevation of the Black-
man pit is 152 feet and of the Barbour pit, 151 feet.

Clay from locality J-162, according to the test data, (Appendix
II) is suitable for the manufacture of common brick, hollow tile,
drain tile, and round tile. This locality is on an extensive terrace
flat, the Pamlico surface. The underlying bedrock is clay of the
Tampa formation.

Brick for some of the older buildings at the Florida Industrial
School for Boys was made from clay obtained on the school grounds.
The exact location of the old pit could not be determined, but it was
reported to have been located near the present highway, Fla. 276,
which would have placed it at a lower elevation than the surround-
ing terrain. The elevation of this clay pit probably was not below
115 feet. The Tampa formation-Suwannee limestone contact in
Well W-1824, located north of the highway at the Boys school, was
found to be at an elevation of 116 feet. The clay found in this pit
was probably derived from clays of the Tampa formation that were
leached relatively free of calcium carbonate.

FLORIDA GEOLOGICAL SURVEY

Exploration for Clay.-An analysis of past clay pit operations
and the tests performed by the Engineering and Industrial Experi-
ment Station, University of Florida, indicate that clays suitable
for the manufacture of brick and other fired ware are most likely to
be found underlying terrace surfaces. The best clays appear to
have been found on either the Pamlico or the Wicomico terraces,
and when these are underlain by clays of the Tampa formation
they offer the most promise.
Sand and Gravel.-Gravel is not abundant in commercial quan-
tities in Jackson County. One deposit was worked years ago. This
pit, located on the Henderson farm, 3.8 miles south of Cottondale on
Fla. Highway 75, at an altimeter elevation of 139 feet, produced
gravel composed of well rounded quartzite pebbles that ranged in
size from one to two inches in diameter. The one inch pebbles are
the most common. The gravel occurs in a red, micaceous clayey
sand, and is composed of badly fractured pebbles which are not
suitable for use in concrete subjected to high stresses.
Sand is abundant in most parts of the county, but it generally
requires washing to remove the clay if a high grade product is
desired. Large quantities of rather coarse sand can be obtained
in the Delta Plains Highlands of the southwestern part of the
county. This sand requires very little washing to obtain clean sand.
Limestone.-There is a sufficient quantity of limestone in Jack-
son County to sustain large commercial quarrying operations. In
the past the Crystal River limestone was quarried for use as road
base courses, and the Marianna limestone was quarried in the early
1800's for use as a building stone. Road base materials are used
from the most available and cheapest source and the Crystal River
is used only where it is available along or near a right of way. The
use of the Marianna limestone decreased as production costs, pri-
marily labor, increased, and today concrete blocks have replaced the
Marianna limestone as a building stone.
The only commercial limestone quarry operating in Jackson
County is owned by the Marianna Limestone Products Co. and is
situated near the center of Sec. 23, T. 5 N., R. 11 W. (loc. J-5). This
company produces crushed agricultural limestone from the Bump-
nose limestone.
The important properties of the Eocene limestones are their
softness, their high calcium carbonate content, and their low
magnesium content. These limestones are suitable for' many pur-

GEOLOGY OF JACKSON COUNTY, FLORIDA

poses: burnt lime products, cement, calcium carbonate fillers, and
chemical uses. The softness of these limestones offers several
advantages which have not been fully investigated. When dry,
these limestones can be ground to a very fine state with minimum
power; however, when wet, the limestone does not crush well and
tends to form a lime mud that clogs conventional hard-rock crushers.
If markets for sufficient crushed limestone can be obtained, new
quarrying and processing techniques seem justified. Portable roof
shelters might be used to protect the rock from the rain thus per-
mitting continuous operation of the crushers. Perhaps a large,
high capacity crusher can be developed that is able to handle soft
rock without serious clogging.

The Marianna limestone is available in quantity at the surface
only in the Marianna-Cottondale area. This limestone is one of the
earliest used building stones in Florida. The soft, compact, cream-
colored rock was sawed into blocks by cross cut saws for use in the
construction of buildings and chimneys. As labor cost increased,
the unit cost of the blocks became so high that now concrete blocks
are used instead of Marianna limestone. Because hand labor was
involved in the production of the limestone blocks, they were not
uniform. This fault gave a further advantage to the concrete block
industry. Untreated Marianna limestone is stained an unsightly
black on exposure by what is probably a fungus growth. While
not suitable for all types of construction, properly designed resi-
dence and two story buildings are sound and durable (figure 26).
The light color of the fresh stone is pleasing for architectural use
and the treatment of the stone to prevent the discoloration caused by
the fungus would enhance the beauty and possible sale of the blocks.
A most attractive residence, built by Mr. Cecil Rhyne of Marianna,
was built of Marianna limestone blocks faced with a ferruginous
sandstone (locally known as "iron rock") (figure 27).
Large reserves of high calcium Crystal River limestone and an
abundance of Miocene clays in Jackson County provide raw ma-
terials for cement manufacture.

Ground Water.-Ground water is plentiful in Jackson County,
and large quantities of water are generally produced from wells
that penetrate the bedrock. This water is normally uncontaminated
but is "hard" because of the presence of dissolved bicarbonates.
The Crystal River formation, the most important source of
ground water, lies at or near the surface in most of the county. The

86 FLORIDA GEOLOGICAL SURVEY

Figure 26.--Community House, Marianna, Florida. This building is con-
structed of Marianna limestone.

S./' 1

Figure 27.-The residence of Mr. Cecil Rhyne, Marianna, Florida. This
house is constructed of Marianna limestone blocks faced with ferruginous
sandstone.

GEOLOGY OF JACKSON COUNTY, FLORIDA

Suwannee limestone and the Tampa formation are also aquifers and
are very important sources of ground water in the southern part of
the county. The terrace sands of the Coharie formation are like-
wise important sources of water in the southeastern part of the
county. Most municipalities and industries obtain their water from
middle Eocene formations which are normally too deep for domestic
users.
Ground water in the Crystal River formation aquifer is artesian,
and water in wells that penetrate the aquifer rises to a level where
the column of water in the well balances the hydrostatic head.
The position of the water levels in wells in relation to the land sur-
face is controlled by the location of the well in the county, the
porosity of the aquifer, the elevation of the surface, the hydrostatic
head, and other hydraulic factors. In Jackson County these levels
generally lie 10-50 feet below the ground surface. Springs are
present in the lower portions of the county; some wells located in
these low places might flow.

Petroleum.-Three petroleum test wells, all dry and abandoned,
have been drilled in Jackson County. A number of stratigraphic
test wells have been drilled, and most of the county has been sur-
veyed by some geophysical means. The fact that the Marianna-
Chipley area is structurally high has been recognized for a number
of years, but results of petroleum exploration in this area have been
discouraging.
Oil is being produced in Florida at the Sunniland field from a
porous zone in evaporites and carbonates of Early Cretaceous age.
The oil production nearest Jackson County is at the Pollard field,
Escambia County, Alabama, and at the Gilbertown field in Choctaw
County, Alabama.
In re-examining the petroleum prospects of Jackson County, a
review of the conditions favorable for the occurrence of petroleum
in the earth's crust is in order. Pratt (1944, p. 1507) points out
that,

"... the primary desideratum continues to be a thick marine series
of rapidly accumulated, plastic, or saline sediments, rich in organic
matter."

The three deep petroleum test wells drilled in Jackson County in-
dicate that a thick section of marine rocks exists. Accumulation of
petroleum is dependent upon the existence of a trap and a suitable

FLORIDA GEOLOGICAL SURVEY

geometric arrangement of caprock and reservoir rock that will
localize the accumulation. It is the search for a trap that has been
most difficult in explorations for petroleum in Florida.
The Marianna-Chipley structural high is a regional feature
and any petroleum accumulations that may be found in this area
can be expected to be in smaller local traps located on this regional
structure. Past success in oil discovery in the eastern Gulf Coast
area suggests that Cretaceous formations offer the greatest promise
for petroleum production in Florida. These formations, in Jackson
County, lie at depths greater than 1937 feet (Cole, 1938). The
present report is concerned primarily with the surface and shallow
subsurface geology of Jackson County; the deeper Cretaceous beds
were not studied. A report being prepared by members of the
Survey on the Panhandle will include these rocks. A number of un-
conformities exist between formations exposed at the surface in
Jackson County and those occurring at depth, so that structures
present at the surface are not necessarily present at depth. How-
ever, structures present at the surface can contribute much to the
interpretation of deeper structures located by geophysical methods
or by stratigraphic drilling. Therefore, the following suggestions
are advanced with these limitations in mind.
One localized structure in Jackson County deserves mention as
a possible petroleum trap, the domed structure on the southeast,
or downthrown side, of the Cypress fault that closes against the
fault (figures 5, 6, 9). This structure and the fault appear to have
developed as a result of post-Suwannee-pre-Tampa stresses. The
depth to which this structural closure persists is unknown, and
it could not be determined from the data at hand whether there
was closure on the northwest, or upthrown, side of the fault. A
more complete description of this structure can be found on page 26.
A number of characteristics of the Marianna-Chipley area make
this structure interesting. The area long has been recognized as a
structural high and four oil test wells have been drilled in the area,
one in Washington County (W-l) and three in Jackson County
(W-285, W-1886, and W-2777).' How long the Marianna-Chipley
area has been a structurally positive area is unknown, but there
is the suggestion that this area was structurally positive at least
as early as Midway time, for Applin and Applin (1944, fig. 23, pp.
1736-1737) show a thinning of beds of Midway age and the absence
of beds of Navarro age at the Hammonds No. 1 Granberry well
(W-285) on their structure section. This well, W-285, is located on

	Title Page
	Frontispiece
	Front Matter
	Table of Contents
	Main

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