<%BANNER%>
HIDE
 Front Matter
 Front Cover
 Frontispiece
 Title Page
 Letter of transmittal
 Table of Contents
 List of Illustrations
 Administrative report
 A preliminary report on the geology...
 The topography and geology of southern...
 Mineral industries
 The fullest earth deposits of Gadsden...
 Index
 Back Cover














Annual report
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Permanent Link: http://ufdc.ufl.edu/UF00000001/00002
 Material Information
Title: Annual report
Portion of title: Annual report of the Florida State Geological Survey
Physical Description: v. : ill. (some folded), maps (some folded, some in pockets) ; 23 cm.
Language: English
Creator: Florida Geological Survey
Publisher: Capital Pub. Co., State printer,
Capital Pub. Co., State printer
Place of Publication: Tallahassee Fla
Publication Date: 1908-1909
Copyright Date: 1930
Frequency: annual
regular
 Subjects
Subjects / Keywords: Geology -- Periodicals -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
serial   ( sobekcm )
 Notes
Additional Physical Form: Also issued online.
Statement of Responsibility: Florida State Geological Survey.
Dates or Sequential Designation: 1st (1907/08)-24th (1930-1932).
Numbering Peculiarities: Some parts of the reports also issued separately.
Numbering Peculiarities: Report year ends June 30.
Numbering Peculiarities: Tenth to Eleventh, Twenty-first to Twenty-second, and Twenty-third to Twenty-fourth annual reports, 1916/18, 1928/30-1930/32 are issued in combined numbers.
 Record Information
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier: ltqf - AAA0384
ltuf - AAA7300
oclc - 01332249
alephbibnum - 000006073
lccn - gs 08000397
System ID: UF00000001:00002
 Related Items
Succeeded by: Biennial report to State Board of Conservation

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Table of Contents
    Front Matter
        Front Matter
    Front Cover
        Front Cover 1
        Front Cover 2
        Front Cover 3
    Frontispiece
        Frontispiece
    Title Page
        Page 1
        Page 2
    Letter of transmittal
        Page 3
        Page 4
    Table of Contents
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
    List of Illustrations
        Page 12
    Administrative report
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
    A preliminary report on the geology of FLorida
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
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    The topography and geology of southern Florida
        Page 175
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    Mineral industries
        Page 233
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    The fullest earth deposits of Gadsden county, Florida
        Page 253
        Page 254
        Page 255
        Page 256
        Page 257
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    Index
        Page 293
        Page 294
        Page 295
        Page 296
        Page 297
        Page 298
        Page 299
    Back Cover
        Page 300
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Digitized by GOOSIe




9?







ict. uill ANNUAL REPORT. FRONTISPIEtC. PL. I.


I l:


Photo by Sellards.
ALUM BLUFF, APALACHICOLA RIVER, FLA. LOOKING UP STREAM. THE SECTION" .'" IN THE TEXT (p. 273) WAS
MADE AT THE i: OSUR. a.d.< IN THE DISTANCE.


t k


_


OLORIDA 09UILOGICAL SURVXY.


. -' .....,... .....








FLORIDA STATE GEOLOGICAL SURVEY
E. H. SELLARDS, STATE GEOLOGIST










SECOND ANNUAL REPORT

1908-09











ADMINISTRATIVE REPORT

MINERAL INDUSTRIES

STRATIGRAPHIC GEOLOGY




INCLUDING A TOPOGRAPHIC AND GEOLOGIC MAP OF FLORIDA
PREPARED IN CO-OPERATION WITH THE UNITED
STATES GEOLOGICAL SURVEY.










PUBLISHED FOR
THE STATE GEOLOGICAL SURVEY
TALLAHASSEE, 1990.


V.
"llow"Itmooftft










































THE RECORD COMPANY
ST. AUGUSTINE
FLORIDA
1909


















LETTER OF TRANSMITTAL.


To His Excellency, Hon. Albert W. Gilchrist,
Governor of Florida.
Sir:-I have the honor to submit herewith a report of the opera-
tions of the State Geological Survey for the year ending June 30,
19.09, constituting the second annual report of the State Geologist.
In addition to the administrative report and the report on mineral in-
dustries, there is included a report on the geology of Florida with
special reference to stratigraphy, to which is added a chapter on the
topography and geology of Southern Florida. This report on stra-
tigraphy has been prepared in cooperation with the United States
Geological Survey carried on in accordance with plans mentioned in
my former report. The Florida Survey has derived much benefit
from this cooperative work and is fortunate in having the report for
publication at this time.
Permit me to express my appreciation of the interest you have
taken in the work of the State Geological Survey, and the assistance
you have given in the prosecution of that work.
Very respectfully,
E. H. SELLARDS,
State Geologist.
Tallahassee, Florida.
October 1, 1909.


212961










CONTENTS.


ADMINISTRATIVE REPORT nv E. i. SKI..ARDS .................. 13
Members of the State Survey force .............. .................. 13
Publications issued ............................................ 13
Distribution of reports........................................ 14
Relation of the State Survey to other organizations ................. 14
The Survey library......................... ................ 15
Exhibition of geological material ................................... 15
The relation of the State Survey to the ownership of mineral I)aring
lands ........................................ . ........... 15
Samples sent to the Survey for examination .................. ...... 16
Collection of statistical information ............................... 16
Financial statement ................... ....... ............. 17
SA PRELIMINARY REPORT ON THE GEOLOGY OF FLORIDA.
with special reference to the Stratigraphy, by GEORGE CHARLTON
MATSON AND FREDERICK G. CLAPP. Prepared in cooperation between
the United States Geological Survey and the Florida State Geo-
logical Survey, under the direction of TIfoMAS WAYLAND VAUGIcAN
Topography and drainage .................................... ... 28
General topographic features .................................... 28
River .. ................................... ......... :
Lakes and swamps ............................................ .31
Lake region ............................................. 32
C averns ............... ............................ ....... 2
Sink holes .................................... ............... 34
Natural bridges ......................... ..................... .. 36
Sand dunes ............................. ...................... 37
Springs ................. ........................... 37
North and West Florida .................................. 38
Erosion features .................... ..................... ...... 3
Lakes .................. .............................. 38
Sand dunes ............................................. 39
Coastal region ................. .................. ............... 39
Streams and ponds ..................... ...................... 3
Ridges ................................................... .... .3
Terraces .................................. ............... 3.
Shore lines ...................................................... 40
Coral reefs ...................................... ......... ..... 40
Submerged continental border ................................. 40
B ars ....................................... ...... ... .... 40
Sounds ............................................... 41
Inlets ............ ........ ........................... ......... 41
Tidal runways ........................................ .... 41
Capes ................... ......................... ......... 42
Soils ............................ ........... ... ....... ... .... . 4
O rigin ................................................ 4:1
Classification ............... ............................... 44
Structure .................... ........... .. .................... 4
Stratigraphic geology ................... .... ................... .. 50
T ertiary ...................... ......................... .......... 50
Oligocene ............................................... .'
S i group ..................................:-







6 CONTENTS.


Stratigraphic geology-Continued. PAGE
Marianna and "Peninsular" limestones..................... 52
Stratigraphic position .......... ..... ...... ........ .52
Lithologic character .................................... 52
Thickness .................... .......................... 53
Physiographic expression .............................. 53
Paleontologic character ................. ............... 54
Structure ................................. ......... 54
Local details ......................... ............. ... .54
Ocala limestone .......................................... 59
Stratigraphic position .................................... 60
Lithologic character ........................... .......... 60
Thickness ............................................... 61
Physiographic expression ................... ....... ........ 61
Paleontologic character ................................. 61
Structure ............................................ 61
Local details ............................................. 61
Miliolite limestone .................. ................... 66
Apalachicola group ........................................ 67
Hawthorne formation ............................. ......... 69
Stratigraphic position ................................... 69
Lithologic character ...................................... 70
Thickness .................................... .... .... 70
Physiographic expression ............... .............. 71
Paleontologic character .................................. 71
Structure ......... .................. ............. 71
Local details .. ............. ........................ 71
Chattahoochee formation ............................... 74
Stratigraphic position .................................... 75
Lithologic character ......... ................. ............ 76
Thickness ............... ................ ......... 75
Physiographic expression ................. ............... 75
Paleontologic character ................................ 77
Structure .......... ........ .............. .... ....... 78
Local details ...................... ..................... 78
Tampa formation ..........._ .. ........ ........... ........ 84
Stratigraphic position ............ ...................... 86
Lithologic character ................. .......... ........ 86
Thickness ................ ............................. 87
Physiographic expression ............. ... ... ........ 87
Paleontologic character ................ ............ .. 87
Structure ............... ........ .......... ........ 88
Local details ............................ ........... 88
Alum Bluff formation ............... .................. 91
Stratigraphic position ................................... 2
Lithologic character ................... ................. 92
Thickness ................ .......................... 94
Physiographic expression .................. .............. !94
Paleontologic character .................................. 95
Structure ............... .... .................. ......... 95
Local details .............................................. 9
Chipola marl member ...................... ":






CONTENTS. 7

Stratigraphic geology-Continued. Pr s.:
Oak Grove sand member ............................ 104
Shoal River marl member ........... ..... .......,. 104
Miocene .............. .......................... 106
General remarks ...................................... ... 100
Jacksonville formation ................................ 108
Stratigraphic position .................................. 10
Lithologic character .................................... 10
Thickness .............. ..... ................. ...... . 110
Physiographic expression ............ ....................... Ill
Paleontologic character ................................ Ill
Structure ..................................... ..... 111
Local details ............................... ....... . 112
Choctawhatchee marl .................................... 114
Stratigraphic position .................................... 114
Lithologic character .................................. 11
Thickness ................. ....................... 116
Physiographic expression............................... 116
Paleontologic character ................... ............ 116
Structure ... .. .......... .......... ....... ........... 116
Local details ............................ ................. 117
Pliocene ...................... .................. ............ 123
Caloosahatchee marl ..................................... 123
Stratigraphic position .................................. 124
Lithologic character .................................... 12
Thickness ................................ ....... .... 124
Physiographic expression ............... .... ............ 124
Paleontologic character ................................. 124
Structure ............. ....................... ...... 125
Local details ................................. ......... 126
Nashua marl ................ ........................... 128
Stratigraphic position .................................... 128
Lithologic character .................................... 12q
Thickness ...................... .................. 129
Physiographic expression .............................. 129
Paleontologic character ................................. 129
Structure ............................. ............ 130
Local details ......................................... 130
Alachua clay ............ .............................. 133
Stratigraphic position .................................. 134
Lithologic character ............... ................... 134
Thickness ...................... .................. 134
Physiographic expression ............................... 134
Paleontologic character ................................ 135
Structure ............. .................. ....... 135
Local details .......................................... 135
Bone Valley gravel ................... .......... ....... 138
Stratigraphic position .................................. 139
Lithologic character ...................................... 139
Thickness ............................................... 139
Physiographic expression ............................... 140
Paleontologic character ......................... ...... 140







8 CONTENTS.


Stratigraphic geology-Continued. PAGE
Structure .. .......... ............ .... . . 140
Local details ............................ ...... ... .... 140
Pliocene (?) .......... .......I ..................... 141
Lafayette formation ....................................... 141
Stratigraphic position .................................. 141
Lithologic character ..................................... 142
Thickness ................... .............. ........... 143
Physiographic expression ................................ 143
Paleontologic character ................................. 143
Structure ................... .................... 143
Local details ........................... .. .. ...... .... .. 143
Q uaternary ...................................... ........... 145
P leistocene ...................................... ........... 146
Fossiliferous m arls ............................. ....... 146
General ................ .......... ............... . 146
Local details ............................................ 148
Gray sand .................... ................. .......... 152
Planorbis rock ................. .......... ...... ... ...... 153
Coquina ....................... ............... ........... 153
Vermetus rock .................... ...................... 154
Yellow sand ............. ........................ ..... 155
Stratigraphic position ............ ..................... 155
Thickness ...................................... .......... 156
Physiographic expression .................................. 157
Paleontologic characters ............. ...................... ... 157
Structure .................. .............................. 157
Recent ................... ..................... ......... 157
Alluvial deposits ..................................... .... 157
Lacustrine de )-ns:ts ............................ : .. ........ 15S
Vermetus rock ............................................ 158
Beach deposits .................. ................... ..... 158
Aeolian deposits .................... ...................... 159
Chemical deposits .................. ... ................. .. ..... 159
H um an rem ains ............. ............................... 160
General Geologic History ......................................... 162
TOPOGRAPHY AND GEOLOGY OF SOUTHERN FLORII)DA, by
SAMUEI SANFORD.
Introduction ................. ............................. 177
Acknowledgments ...................... ................... 178
Object of Report ................................... .......... 178
Topography .............................................. 179
General features ............................................... 179
Shape of the land mass ......................................... 180
Features of the mainland ......................................... 180
Pinelands ....................... ........................... 181
Dunes ........ ................ ............................ .. IS
Rolling sand plains ............... ....... ................ ....... 185
Flat lands ....... ..................... ...... .............. ... 186
Rock ridges ..... ............................................ ... 186
Swam ps ........................ ....... ............ 188
Everglades ................................. ................... 189
Elevation .............. ..... ........................... 190








CONTENTS. i


Topography-Continued, pr I.
Bedrock surface .................. ............ .......... I i
O rigin ........................................ ........ 3
Cypress swam ps ............................................. 19i
Coastal swamps ........................................... 194
The keys .................................... ....... ......... 19.
The Florida reef ................................................. 19
Shore line topography .......................................... 19.
Waste and growth of the mainland and keys...................... 200
Recent changes of level......... ................................ 01
Geology .................................... .................... 202
General statement ....................... ........... ......... 202
Pre-Pleistocene formations ........................................ 203
General statement ................................... ..... 203
Evidence from well records ................................... 203
Palm B each ....................................... ........ 204
Key Vaca ................ ............................ 204
Key West ......................................... .. .. . 205
Buck Key ............................................ 206
O ligocene ...................................... .... .......... 207
Thickness .............................................. 207
Miocene and Pliocene ............. ................................ 207
Lithology ....................................... 207
Thickness ....................................... ............. 207
Source of siliceous materials............................ ....... .. 207
P leistocene ................................. .. ..... ... .... ... ... 208
U exposed beds ........................ .................... 208
Exposed beds .................... .... ......... .......... 209
Palm Beach lim estone ........................................ ... 209
Synonymy ............. .... ............ .. 209
Stratigraphic position .. ......... ................................... 20
Lithologic characteristics ................... ..... ........... 210
Thickness ............................ ............. ............ 210
Physiographic expression ............... ..... ................ 210
Palcontologic characteristics ............... .................... 210
A real distribution ........................... ..... ............ 21)
Structure ............... .. ....................... ........ ... 211
Miami oolite ................................................... 211
Synonymy. .......... ..... .......................... ....... ... 11
Stratigraphic position .......................................... -21
Lithologic characteristics ................................. .... 21
T hickness .............. ........................................ 21 :1
Physiographic expression .................................... ... 21
Paleontologic char::cteristics ........................... ........ 21
Areal distribution ................. .. .......... ......... 21
S tru ctu re ....................................... ................ 1
Correlation ............................................ 214
Key Largo limestone ............... ................ ...... 214
....................................................... 214
Stratigraphic position ............................... ........... 21.
Lithologic characteristics .......... ......... ......... ......... . 21
Thickness .................................................
Physiographic expression ....................... ... ....; .








10 CONTENTS.


Key Largo limestone-Continued. PAC,
Paleontologic characteristics ..................................... 217
Areal distribution ............................... ...... ... . . 217
Exposures ................. ......................... . 218
Key West oolite ................... ................... ............ 218
Synonymy ..................................... ............... . 218
Stratigraphic position ................. ................... .... 219
Lithologic characteristics .......................... ............. 219
Thickness ........... .. .. ...... ... .......... 219
Physiographic expression ...................................... 220
Paleontologic characteristics ........... ................... ... 220
Areal distribution ........................ ...................... 221
Origin of Florida oolites ................... ..................... 221
Lostmans River limestone ........... ..................... ....... . 222
Synonymy ......................... .............. 222
Stratigraphic position ................ .......................... 223
Lithologic characteristics ........... ............. ...... ... 223
Thickness ............... ....................................... 223
Areal distribution .................... ..................... ..... 224
O rigin ... ....... .... ........ ............ .... ... . 2.4
Coquina ................................................ 225
Sands ............................. ...................... 22
Lithology of Pleistocene beds ...................................... 227
Thickness of Pleistocene beds...................................... 227
Recent ... .............. ..... ... . ................... .22
Peat .......................................................... 22S
M arl ................................. ..... ... ...... ........ 228
Sands .......... ... ................ ......... ...... .229
Coral reefs ............................................ 229
Worm rock ...................................... ............. 230
Oyster banks ................................... ........ 230
P;cistocene and Recent History of Southern Florida ................. 231
MINERAL INDUSTRIES, by E. H. SELLARDS.
Phosphate ....................................... ...... 235
Varieties ............................... ......... ........ 235
Location .................................... .................. 235
Production for 1908 ............................... ............... 236
Loss of phosphate in mining ................................... 240
Clay ................. .............. ...................... 2!2
Plastic kaolin or ball clay ............... .... ................ 212
Brick making clay ................... .. ...................... 243
Peat .............................. .. .................... 243
Diatomaceous c:arth ........................ ................. 244
Limr :.nd ground limestone .... .. .. ................... 245
Sand-lime brick ............................... ................ 2245
Building stone ..................... . ................. .......... 246
Materials for mortar ;nd concrct" ....... ......... ................ 247
M inerals new to the S:ate.............. .. .................... 250
M alachite ............................ ......................... 250
THE FULLERS EARTH DEPOSITS OF GADSDEN COUNTY,
with Notes on similar Dl)posits found elsewhere in thl State, by
E. H. SEILARDS AND HERMAN GUNT:R.
Preface .............................................. ...







CONTENTS. 11

The fullers earth deposits-Continued. ir\r,.
Introduction ........................ .......... .. .. .............. 257
Mineral constituents of fullers earth........................... 257
Physical properties ............................................ 258
Tests ................. .............. ... ..... ............ 258
U ses ........................ .. ... ..................... 259
Methods of mining ................... ....... ....... ..... 259
Production of fullers earth .................. ................... 260
Discovery of fullers earth in America .............. ........... 260
Fullers earth deposits of Florida ................................. 26t
Gadsden County ........ .................. ............. 261
Geography and topography .................................. 261
Geology ....................................... .... . 26:
The Apalachicola River section................................ 2 i
Section at Chattahoochee Landing and in the vicinity of Chat-
tahoochee and River Junction......................... 257
Section at Aspalaga Bluff .................................. 271
Section at Rock Bluff.................................... 273
Section at Alum Bluff.................................... 275
Minor folds in the Chattahoochee limestone................... 277
Dip of the Chattahoochee limestone........................... 277
The Ocklocknee River section .............................. 279
Fullers earth outcrops in Gadsden County..................... 280
Section in Owl Commercial Co.'s pit at Quincy.............. 282
Section on public road one mile east of Quincy............. 283
Section on Quincy-Attapulgus road, five miles northeast of
Quincy .................................. .......... ?28
Section one mile west of Gatzlaff on west side of Attapulgus
Creek ....................... ..................... 283
Section at public road crossing on Bear Creek ............... 28:
Section on Crooked Creek .................. ............... 283
Section at Nicholson .................................... 284
Amount of fullers earth in Gadsden County................... 285
Liberty County' .. ............ ....... ................... ...... 28:
Notes on fullers earth ................. ......... .......... 2S8
Leon County .............................. . .. ...... 28'i
Notes on fullers ;.rch. ......................................... 286
Colum bia County ................ .......... ... ........ ...... 287
Notes on fullers earth ............. ......... ............. 287
Alachua County ....................... ............. ....... 287
Notes on fullers earth .............. ... .............. ....... 288
Section at "Devil's Mill Hopper.......................... 288
Marion County ................ ....... .................... 288
Notes on fullers earth .............. ......... ............. 289
Section at Belleview................... ..... ............... 280
Manatee County .. ................. ............ 289
Notes on fullers'earth ..................... ............ ...... 289
Sections in pit of Atlantic Refining Company.................. 21
Section at the abandoned pit of the Columbia Fullers Earth
Company .............. ............. ............. 291
Amount of fullers earth in Florida ............................. 291
In d ex ...... .............. ....... . ....... ..... ............ 29







ILLUSTRATIONS.


PLATES.
PLATE. FACING PAGE.
I. Alum Bluff on Apalachicola River, Florida ................ Frontispiece
II. *Fig. 1. Sink hole, southeast of Vernon. Type of topography
of Vicksburg group ............................ 58
Fig. 2. "Falling Water," five miles south of Chipley....... 58
III. Fig. 1. Ocala limestone. Quarry of Ocala Lime Company. 64
Fig. 2. Ocala limestone ledge in pit of Fort White Hard
Rock Phosphate Company, Fort White..'........ 64
IV. Fig. 1. Outcrop of Hawthorne limestone on Suwanee River
opposite Ellaville ........ ..................... 74
Fig. 2. Limestone of Tampa formation, Hillsboro County. 74
V. Fig. 1. Cut on the G. S. and F. R. R., near Kent, Nassau
C county ....................................... 100
Fig. 2. Alum Bluff formation, near White Springs on Su-
w anee R iver ................................... 100
VI. Fig. 1. Land pebble phosphate, showing-bxdded deposit.... 140
Fig. 2. Pleistocene terrace, St. Marys River ............... 140
VII. Fig. 1. Conglomerate of Lafayette formation: Rock Hill.. 154
Fig. 2. Coquina rock, Anastasia Island. St. Augustine..... 154
VIII. Fig. 1. "Rise" of the Santa Fe. River................... 160
Fig. 2. Ancient shell mound, Indian River...: ............ 160
IX. Fig. Quarry in Miami oolite, Keys Station, Dade Count, 212
Fig. 2. Reef rock overlain by-marl.. Knights Key......... 212
X. Fig. 1. Erosion by spray in Key Largo limestone, Knights
K ey ................................. ... .... 218
Fig. 2. Beach ridge of calcareous sand. Cape Sable........ 218
XI. Hard rock phosphate mining region...................... 236
XII. Land and River pebble phosphate mining region........... 238
XIll. Fig. 1. Plate rock phosphate mining, Anthony. Marion
County ...................................... 240
Fig. 2. Removing overburden, land pebble phosphate, Mul-
:rr: .............. .... ... ................. 240
XIV. Fig. 1. Plastic Kaolin mine. Edgar, Putnam County....... 244
F:g. 2. Dredge excavating p-at, North Canal, near Fort
Lauderdale. Photo by Matson..... ............. 244
XV. Fig. 1-6. Sands for mortar .............................. 248
XVI. Fig. 1. Fullers earth plant at Ellenton, Manatee County... 25
Fig. 2. Fullers earth plant at Quincy. Gadsden County... 258
XVI1. Fig. 1. Apalachicola River looking south from Alum Bluff. ::
Fig. 2. Exposure of Chattz:hoochee limestone on A. C. ,.
R. R. River function ......................... ...;
XVIII. Map of fullers earth exposures in Gadsden and Liberty
C ou lnties ..................................... 2S1
XIX. Fig. 1. View i-1 p;t o Owl Commercial Company, Quincy. 2S4
Fig. 2. View in pit of Owl Commercial Compa:ly, Quincy. 284
TEXT FIGURES. PAGc.
Fig. 1. Map showing sink holes ... ............. .............. 3:
Fig. 2. Solution channel in limestone ........................... :If
Fig. 3. Section along drainage canal........................... 193
Fig. 4. Section at Chattahoochee Landing............... .........
Fig. 5. Section at Aspalaga Bluff ...................... ....... 272
NM A P.
Topographic and Geologic Map of Florida....................... In pocket










FLORIDA -STATE GEOLOGICAL SURVEY.
E. H. SELLARDS, STATE GEOLOGIST.


ADMINISTRATIVE REPORT.


The members of the State Survey force during the past year have
been, in addition to the State Geologist, Mr. Herman Gunter, Dr.
R. M. Harper, and during a part of the year Professor N. H. Cox.
The chemical analyses necessary to the work of the State Survey are
made by the State Chemist.
Mr. Gunter has assisted in the preparation of the paper on fullers
earth deposits which accompanies this report. In addition he has had
charge of cataloguing and recording the Survey collections.
Dr. Harper's connection with the Survey began in December, 1908,
since which time he has been engaged in an investigation of the peat
resources of the State. The peat deposits form a natural resource the
value of which can not fail to be appreciated as other fuels become
exhausted, and Dr. Harper's report will do much to further the de-
velopment of this industry. The fuel tests of peat samples for this
purpose are being made in the fuel testing laboratory of the United
States Geological Survey.
Professor N. H. Cox, of the department of civil engineering of
the State University, was engaged during the summer of 1908 in an
investigation of the roads and road making materials of the State.
In addition to the necessary correspondence and administrative-
work of the office, the State Geologist has completed the field investi-
gations for a preliminary report on the fullers earth deposits, and
has carried on field work with a view to the publication of a report
on the phosphate deposits.
PUBLICATIONS ISSUED.
Two publications have been issued during the year as follows:
The First Annual Report covering the operations of the State Geo-
logical Survey for the year 1908-09, and Bulletin No. I of the Sur-
vey, on the underground water supply of central Florida.
The annual report contains: (1) A sketch of the geology of
Florida; (2) a chapter on mineral industries, including phosphate.
kaolin or ball clay, brick-making clays, fullers earth, peat, lime and
cement, and road making materials; (3) a bibliography of publica-
tions on Florida geology with a review of the more important papers





VI.ORIDA STA.TIt (;CF.OLOGICAL SURVEY.


published previous to the organization of the present Geological.
Survey.
The bulletin" contains: (1) Underground water: general dis-
cussion; (2) the underground water of central Florida, deep and
shallow wells, springs and artesian prospects; (3) effects of under-
ground solution, cavities, sink-holes, disappearing streams, and solu-
tion basins; (4) drainage. of lakes, ponds and swamp lands, and dis-
posal of sewage by bored wells. Water analyses are included as well
as tables, giving general water resources, public water supplies, spring
and' well records.
DISTRIBUTION OF REPORTS.
The reports issued by the Survey are distributed upon request to
citizens and to city and to other public libraries. The results of the
Survey thus become permanently available to those interested in the
geology or mineral resources of the State.
RELATION OF THE STATE SURVEY TO OTHER ORGANIZATIONS.
U. S. Geological Survey:-Cooperation with the National Geo-
logical Survey was arranged soon after the organization of the State
Survey. During 1907-08 this cooperative work was devoted chiefly
to an investigation of the general geology and stratigraphy of the
State and the underground water supply. Bulletin No. 1 already
referred to formed a part of the results of this cooperative work. A
special report on the stratigraphy of the State forming a second part
of this cooperative work accompanies this report. During the present
year the State Survey has fortunately been able to extend cooperation
with the National Survey to include testing of peat samples for fuel
purposes. These tests form a part of and will be included in the
report on peat deposits.
U. S. Department of Agriculture:-The Director of the Division
of Roads and Road Materials of the U. S. Department of Agriculture
has very kindly consented to make the necessary tests of samples of
road material of Florida taken in connection with the investigation
of roads and road material by the Florida Survey.
Geological Surveys of Neighboring States: Geological forma-
tions are limited by no such lines as State boundaries, and an intelli-
gent study of a formation often necessitates a knowledge of its extent
and development in a neighboring State. The relationship of a State
Survey is therefore close with neighboring States, and particularly
with adjoining States. This relationship in the case of the Florida
Survey is especially close with Georgia and Alabama. With more
distant States there is a no less real relationship growing out of a
similarity of deposits, and of methods of study and development.






SECOND ANNUAL REPORT.


Office of State Chemist:-The Survey law provides that analytical.
work necessary to the investigations of the Survey shall be done by
the State Chemist. The Survey is thus brought atp -co-operative
relation with the Division of Chemistry ofthe Department of Agri-:
culture and in so far as the work of the. Survey corntibutes to agri-
cultural interests, to the Department of Agriculture as-a whole.
The State Agricultural Experiment Station:-In its study of the.
water supply in relation to agriculture, of soils in their geological.
relations, and in other ways, the work of the State Survey may be.
expected to supplement certain lines of work of the State Experiment.
Station, the two organizations being of mutual aid to each other.
State Colleges and Other Educational Institutions:--The State
Survey law provides that duplicate suits of specimens obtained by the
Survey illustrating the geological and mineral features of the State
shall be deposited with the State Colleges. The publications of the
State Survey are placed in the libraries of all of the educational insti-
tutions desiring them.
THE SURVEY LIBRARY.
A well-equipped reference library is essential to the best results
and an effort is being made to bring together those publications which
are necessary to.the immediate and future work of the Survey. The
Survey library now contains more than 1,500 volumes. These include
the reports of the several State Geological Surveys; the Annual Re-
ports, Bulletins, Monographs, Professional Papers, Water Supply and
Irrigation Papers, and other publications of the Nalional Geological
Survey; the reports of the Canadian, and a few other foreign Geo-
logical Surveys; and many miscellaneous volumes and papers on geo-
logical subjects. Additions to the Survey library will be appreciated.
EXHIBITION OF GEOLOGICAL MATERIAL.
The Survey law provides for the exhibition of geological material.
The space available for this purpose is unfortunately as yet very lim-
ited. A part of one room has, however, been used for- this purpose.
Three cases have been built, designed to serve the double purpose of
storage and exhibition, the lower part of the case being adapted to
the purpose of storing material. In making the collections a system-
atic plan has been followed to secure a representation of the rocks,
minerals, and fossils of each formation in the State. The collections
will be added to as opportunity permits.

THE RELATION OF THE STATE SURVEY TO THE OWNERSHIP OF MINERAL-,
BEARING LANDS.
The relation of the State Survey to the ownership of mineral-bear-
ing lands is specifically defined. The Survey law provides that ii -1, d!





I,.ORIDA STATE GEOLOGICAL SURVEY.


be the duty of the State Geologist and his assistants, when they dis-
cover any mineral deposits or substance of value, to notify the owners
of the land *upon which such deposits occur before disclosing their
location to any other person or persons. Failure to do so is punish-
able by fine and imprisonment. It is not intended by the law, how-
ever, that the State Geologist's time shall be devoted to examinations
and reports upon the value of private mineral lands. Reports of this
character are properly the province of commercial geologists, who
may be employed by owners of land for that purpose. To accomplish
the best results, the work of the Survey must be in accordance with
definite plans by which the State's resources are investigated in an
orderly manner. Only such examinations of private lands can be
made as constitute a part of the regularly planned operations of the
Survey.
SAMPLES SENT TO THE SURVEY FOR EXAMINATION.
Samples of rocks, minerals and fossils will be at all times gladly
received, and reported upon. Attention to inquiries and general cor-
respondence are a part of the duties of the office, and afford a means
through which the Survey may in many ways be useful to the citizens
of the State.
The following suggestions are offered for the guidance of those
submitting samples:
1. The exact location of all samples should Le given. This should
be carefully written out in full and placed on the inside of the package.
2. The statement accompanying the sample should give the con-
ditions under which the specimen occurs, whether an isolated frag-
ment or part of a larger mass or deposit.
3. Each package should be addressed to the Florida State Geo-
logical Survey, Tallahassee. The name and address of the sender
should be plainly written on the outside.
4. Transportation charges, whether by mail, express or freight,
should in all cases be prepaid.
THE COLLECTION OF STATISTICAL INFORMATION.
For many purposes the collection and publication of statistical in-
formation is helpful, both to the industries concerned and to the gen-
eral public. Such statistical information is desired from all the min-
eral industries of the State. Such information will be recognized as
strictly confidential in so far as it relates to the private business of any
individual cr company, and will he used only in making up State and
County totals. The co-operation of the various industries of the
State is invited in order that the best possible showing of the State's
products may he made annually.







SECOND ANNUAL REPORT.


FINANCIAL STATEMENT.

The total appropriation for the State Geological Survey is $7,500
per annum. With the exception of the salary of the State Geologist
the amount of which is fixed by statute, all Survey accounts are paid
upon warrant issued by the Comptroller as per itemized vouchers
approved by the Governor. The following is a list of the expenses
of the Survey for the year ending June 30, 1909. The original of all
bills and the itemized statements of all expense accounts are on file
in the office of the Comptroller. Carbon copies of the same are on
file in the office of the State Geologist:

July, 1908.
E. H. Sellards, salary for the quarter ending June 30, 1008, charge-
able to funds of the year covered by this report................$ 189.46
Herman Gunter, Assistant, salary, June, 1908...................... 75.00
Nellie Mathes, stenographer, salary, June, (half month)........... 30.00
E. H. Sellards, State Geologist, expenses, May and June, 1908...... 57.65
Herman Gunter, traveling expenses, June, 1908 .................... 36.35
John McDougall, postage ....................................... 13.49
Herrick and Cowell, peat testers ................................. 24.00
E. P. Greene, Arcadia, Fla., tripod................... ............. 3.00
Eimer and Amend, supplies........................... ............ 8.90
American Peat Society, journal .................................. 2.00
W. H. Lowdermilk, Washington, publications ..................... 1.87
Hill Publishing Company, publications............................ 8.20
University of Chicago Press, Journal of Geology................... 3.00
S. H. Coleman, Tallahassee, painting sign.......................... 4.10
G. E. Stechert and Company, publications.......................... 14.25
Iowa Geological Survey, publications ...................... ..... 13.75
Economic Geology Publishing Company, Economic Geology........ 3.00
Capital Publishing Company, printing............................. 40.25
N. H. Cox, Assistant, salary ($58) and expenses ($67.35), July 1-18 125.35
Nellie Mathes, stenographer, salary, July (two-thirds month)...... 40.00
Capital City Livery Stables, drayage ............................ 1.80


August, 1908.
E. H. Sellards, State Geologist, traveling expenses, July and August
Nellie Mathes, stenographer, salary, August ......................
Geological Society of America, publications .......................
The H. & W. B. Drew Co., supplies .............................
September, 1908.
E. H. Sellards, salary for the quarter ending Sept. 30, 1908.........
Herman Gunter, Assistant, salary, July to September...............
Nellie Mathes, stenographer, salary, September....................
N. H. Cox, Assistant, salary ($30) and expenses ($30), August 3-13
Minnie Milligan, stenographic work..............................
Capital Publishing Co., printing.................................
Maurice-Joyce Engraving Co., engravings .........................


46.94
60.00
1.40
6.60


625.00
225.00
60.00
60.00
9. 1
573.60
62.98


Carried forward ........................................ 1 ',,







FLORIDA STATE GEOLOGICAL SURVEY.


Brought forward ...................................... ....$2,425.12
October, 1908.
E. H. Sellards, State Geologist, traveling expenses, Sept.-Oct........ 60.01
Nellie Mathes, stenographer, salary, October .................... 60.00
Gilmore and Davis, office supplies............................... 13.45
W. H. Lowdermilk & Co., publications........................... 21.25
Capital Publishing Co., printing .................................. 512.00
Capital Publishing Co., printing ............ ..................... .2.50
John McDougal, Postmaster, postage ............................ 150.00
November, 1908.
E. H. Sellards, State Geologist, traveling expenses, November...... 62.94
Nellie Mathes, stenographer, November .......................... 0.00
Munson Supply Co., typewriter keys............................ 3.50
December, 1908.
E. H. Sellards, State Geologist, traveling expenses, December...... 61.90
E. H. Sellards. salary for the quarter ending Dec. 31, 1908.......... 525.00
Herman Gunter, Assistant, salary, October-December............. 225.00
R. M. Harper, Assistant, salary ($100.00), expenses ($72.24)....... 172.24
SThe D. R. Cox Furniture Co., supplies ........................... 5.03
Engineering and Mining Journal, publications .................... 1.00
J. K. Small, publications ................... ...................... 4.12
Board of Managers, City Water and Light Plants, supplies......... 13.10
January, 1909.
E. H. Sellards, State Geologist, traveling expenses, January........ 41.50
R. M. Harper, Assistant, traveling expenses ($39.81), salary ($100). 139.81
Herman Gunter, Assistant, traveling expenses ($8.65), salary ($75). 83.65
February, 1909.
E. H. Sellards, State Geologist, traveling expenses, February........ 96.89
R. M. Hair, Assistant, traveling expenses ($60.25), salary ($100). 160.25
Herman Gunter, Assistant, traveling expenses ($34.89), salary ($75) 109.89
Nellie Mathes, stenographer .................................... 12.50
The H. & W. B. Drew Co., supplies ........................... 5.00
March, 1909.
E. H. Sellards, State Geologist, traveling expenses, March.......... 81.44
E. H. Sellards, salary for the quarter ending March 31, 1909........ 625.00
R. M. Harper, Assistant, traveling expenses ($2.25), salary (half
month, $50.00) ............................................. 52.25
Herman Gunter. Assistant, traveling expenses ($12.71), salary ($75) 87.71
John McDougal, Postmaster, postage ............................ 10.00
April, 1909.
E. H. Sellards, State Geologist, traveling expenses, April.......... 46.90
R. M. Harper, Assistant, traveling expenses ($60.05), salary ($70).. 130.05
Herman Gunter, Assistant, traveling expenses ($67.35), salary ($75) 142.35
May, 1909.
E. H. Sellards, State Geologist, traveling expenses, May, 1909...... 70.25
R. M. Harper, Assistant, salary ($100), traveling expenses ($56.35) 156.35
H. Gunter, Assistant, salary, May, 1909 ............................ 75.00

Carried forward ....................... ............... .$,6'05.95.







SECOND ANNUAL REPORT.


Brought forward ...................... ....................$6,605.95
Keuffel, Esser & Company, one Abney level...................... 13.93
H. & W. B. Drew Company, supplies............................ 32.56
Alpha Photo Engraving Company, engravings .................... 28.90
American Journal of Science, subscription for 1909 .................. 6.00
June, 1909.
E. H. Sellards, State Geologist, salary for the quarter, ending June
30, 1909 ...................................................... 625.00
R. M. Harper, Assistant, salary ($100), traveling expenses (33.04). 133.04
H. Gunter, Assistant, salary ($75.00).............................. 75.00
E. H. Sellards, State Geologist, traveling expenses.................. 45.15
Maurice Joyce Engraving Co., engravings ....................... 19.17
Ware Bros. Co., publications ................ ............. 6.00
Hill Publishing Co., publications................................ 10.00
Economic Publishing Co., Economic Geology ..................... 3.00
The Macmillan Co., publications................................... 8.52
The University of Chicago Press, Journal of Geology ............. 3.00
Frances J. Bulask, publications.................................. 2.00

Total expenditures .........................................$7,617.22
Overcharge .......................................... .. 117.22

S,5o00o.



























A PRELIMINARY REPORT ON THE GEOLOGY oF FLORIDA

WITH SPECIAL REFERENCE TO THE STRATIGRAPHY

BY GEORGE CHARLTON MATSON AND FREDERICK G. CLAPP.




INCLUDING A CHAPTER ON THE

TOPOGRAPHY AND GEOLOGY OF SOUTHERN FLORIDA

BY SAMUEL SANFORD.




PREPARED IN COOPERATION BETWEEN THE UNITED STATES GEOLOGICAL
SURVEY AND THE FLORIDA STATE GEOLOGICAL SURVEY, UNDER
TIE DIRECTION OF THOMAS WAYLAND VAUGHAN.




















DEPARTMENT OF THE INTERIOR
UNITED STATES GEOLOGICAL SURVEY
WASHINGTON.
OFFICE OF THE DIRECTOR.


Dr. E. H. Sellards, State Geologist of Florida,
Geological Survey of Florida, Tallahassee, Florida.
Dear Sir: I herewith transmit the manuscript and illustrations of
a Preliminary Report on the Geology of Florida, with especial refer-
ence to the Stratigraphy. By George Charlton Matson and Frederick
G. Clapp. Including a chapter on the Topography and Geology of
Southern Florida. By Samuel Sanford. Prepared in cooperation be-
tween the United States Geological Survey and the Florida State
Geological Survey, under the direction of Thomas Wayland Vaughan.
This report has been prepared in accordance with the agreement
entered into by the Florida State Geological Survey and the United
States Geological Survey on the first day of August, 1907, and is
transmitted to you for publication by the Florida State Geological
Survey.
Very respectfully yours,
GEO. OTIS SMITH,
DIRECTOR.











A PRELIMINARY REPORT OF THE GEOLOGY OF FLORIDA

WITH SPECIAL REFERENCE TO THE STRATIGRAPHY

GEORGE CHARLTON MATSON AND FREDERICK G. CLAPP.


INTRODUCTION.

OBJECT AND SCOPE OF REPORT.

Previous Information Regarding the State:-Although Florida
was settled early in the history of colonization, various natural causes
have cooperated to retard the development of the State's resources.
At the present time Florida contains the largest unsettled area in the
eastern part of the United States.
Various papers containing information relating to the geology of
the State have appeared in scientific journals at intervals, especially
during the last twenty years of the nineteenth century.1 Such insti-
tutions as the Wagner Free Institute of Science of Philadelphia have
published the results of extensive investigations, and the U. S. Geo-
logical Survey has at various times sent parties into the State. Numer-
ous scientists, attracted to the South by the delightful climate during
the winter months, have attempted, with varying degrees of success,
to solve some of the geologic problems; but prior to 1907 no State
Geological Survey had been authorized by the legislature and no
stratigraphic report, published by the State, of a popular and compre-
hensive nature has appeared. A prominent object of the present
report is to fulfill this important task.
Insufficiency of Knowledge:-It is a fact that, in many States, the
geologic conditions are so complicated and diverse that few persons
other than geologists and parties engaged in prospecting or develop-
ing the mineral resources have even a fair idea of the character,
sequence, and significance of the strata, and this is true particularly
in Florida. Indeed, this characteristic is more striking in Florida
than in many other States, because the greater part of the State is
low, and the older geological formations are obscured by a thick
mantle of sand. An incorrect belief, still held by many, and unfor-
tunately taught until recently, is that' the Florida peninsula is
entirely a coral formation. Few people who have not made the sub-

'For a bibliography of the geology of Florida see First Annual Report,
E. H. Sellards, 1908.






FLORIDA STATE GEOLOGICAL SURVEY.


ject a study realize that the geologic formations and structure in Flor-
ida are in reality very diversified. It is to throw some light on these
that the present report is .published. An effort has been made to
bring together information relating to the geology of Florida and to
supplement the knowledge already available with such observations
as were possible in the time allotted to the work. However, this
report is to be regarded as preliminary, and it is expected that further
work will not only add new facts, but will also lead to some revision
and modification of the views now held. In the body of the report
several unsolved problems are indicated, but it should be borne in
mind that not all of them are enumerated.
Sources of Information:-As is usually true of reports covering
large areas, the data incorporated here are derived from many differ-
ent sources. All previous literature has been carefully studied and
the different views compared and brought up to date. giving credit
to the respective investigators. Particularly helpful has been the
work of Dr. W. H Dall, of the U. S. Geological Survey, who has
made extensive investigations of the paleontology of the State, and,
in 1892, published a treatise of nearly a hundred pages, incorporated
in Bulletin 84, of the U. S. Geological Survey, in which he outlined
the stratigraphic geology of the State as well as it could then be done.
A later report by Dr. Dall was published in the transactions of the
Wagner Free Institute of Science. This publication is primarily
paleontologic, but it also contains a resume of the geology and the
stratigraphy of the State. These papers have furnished much valu-
able information which has been incorporated in this report and is
specifically acknowledged elsewhere. The work has been carried on
under the immediate supervision of Dr. T. \ayland Vaughan, of the
U. S. Geological Survey. In addition to exercising general over-
sight of the work, Dr. Vaughan has examined and identified the fos-
sils collected during the progress of the investigation. He has very
generously placed his own extensive notes-accumulated during a
series of years-at the disposal of the writers, and has aided both by
advice and assistance in the field and in the office. The investigations
of Drs. Dall and Vaughan have been of great value because they have
formed a basis for all subsequent work. Other geologists, prominent
among whom are Dr. E. A. Smith, Prof. Angelo Heilprin, and Prof.
Louis and Dr. Alexander Agassiz. have added much to the knowledge
of the geology of Florida.
After the first discovery of phosphate in Florida Mr. George H.
Eldridge was sent by the National Survey to make detailed investiga-
tions of the deposits of that material. He obtained much valuable
data, but, unfortunately, did not live to prepare his final report. His







SECOND ANNUAL REPORT.


notebooks have been available and were occasionally drawn upon by
the writers.
The investigations leading to the present report were enabled
primarily through the passage of the act incorporating the new State
Survey. At the same time the National Survey was engaged in a
comprehensive investigation of the geology of the Atlantic and Gulf
Coastal Plain of the United States, and hence cooperation between
the two bureaus enabled a more thorough study than could have
been carried out in a single season by either bureau alone.
In October, 1907, Mr. Clapp began a field study of the stratigraphy
and underground water resources of Florida. In November he was
joined by Mr. Matson, and together they remained in the field con-
tinuously until May 1, 1908, visiting nearly every town in the State
and gathering as many data as time would permit.
Having exhausted the funds available for field expenses, the writ-
ers repaired to the office about May 1, 1908. On July 1, 1908, Mr.
Clapp resigned from the U. S. Geological Survey, and the work of
preparing the manuscript for the report was entrusted to the senior
author. The base map which accompanies the report was prepared
by the Topographic Branch of the U. S. Geological Survey.
ACKNOWLEDGMENTS.

The interest and cooperation of the people of Florida have rendered
this work a pleasure, and the authors wish to make public acknowledg-
ment of the numerous favors and courtesies extended to them while
in the field and office. Several persons deserve particular mention,
among them being Dr. J. N. MacGonigle, of Miami, and Mr. Goff,
J. C. Meredith. Constructing Engineer, Key West Extension, and
other officials of the Florida East Coast Railway, for affording
opportunity to visit the extension of the railroad during process of
construction.
Hon. Frank Clark, of Gainesville, furnished introductions which
greatly facilitated the work. Dr. De Witt Webb, of St. Augustine,
and Dr. E. S. Crill, of Palatka, have interested themselves in the
work. Many well drillers have furnished logs and records which
added valuable data to our knowledge of the underground stra-
tigraphy, and it is a pleasure to mention particularly Capt. Alexander
Near, of Eau Gallie; Mr. H. C. Haven, of DeLand; Mr. W. D.
Holcomb and Mr. Edward Pettigrew, of Manatee; Mr. H. W. Pearce,
of Arcadia; Mr. H. Walker, of St. Augustine, and Mr. Wm. E.
Hughes, of Charleston, S. C. All these and many others, who can not
be mentioned on account of lack of space, have given substantial assist-
ance. Many citizens have interested themselves in acting as guides
and in furnishing specimens and samples from v 1ll. Tinl nt4 tt~;,. M,






FLORIDA STATE GrOLOGICAI. SUIR\VEY.


the Atlantic Coast Line Railroad, the Seaboard Air Line Railway, the
Florida East Coast Railway and the Louisville and Nashville Rail-
road, in Jacksonville, Wilmington, Norfolk and Louisville, have
allowed access to their profiles and other records, which gave valuable
information for use in the construction of the topographic map of
the State.
At the time when the field work for this report was begun Mr.
Samuel Sanford was engaged in geologic work for the Florida East
Coast Railway. The task of investigating the geology of the Keys
and the southern end of the State was entrusted to him. The results
of Mr. Sanford's work are incorporated in a subsequent chapter.

TOPOGRAPHY AND DRAINAGE.
General Topographic Features:-While Florida is a region of com-
parative slight relief, its surface configuration presents considerable
diversity, ranging from the nearly level plain in the coastal region
and the Everglades to the deeply dissected upland in the northern
part of the State, where much of the surface is trenched by steep
walled valleys, and the highlands of the peninsula where the surface
often consists of a series of more or less rounded depressions separated
by narrow divides. The range in altitude varies from sea level along
the coast to over 'O00 feet above tide at various points on the ridge
which forms the center of the peninsula and to about 100 feet above
the same datum near the northern boundaries of Gadsden, \Walton.
Santa Rosa and Escambia Counties.
The accompanying topographic map (in pocket) is intended to
show the approximate areas of land which lie above and below certain
altitudes. The datum plane is mean sea level, and the contour lines
show the variations in altitude for each fifty feet. This map embodies
the results of the earlier topographic surveys, the river surveys of
the U. S. Army engineers, and the various railroad surveys, together
with a large number of barometric determinations which were made
during the 1,.-!, -.. of the field work. While the exact location of
the contours is sometimes more or less uncertain, it is believed that
they are sufficiently accurate to give a good idea of the relative areas
of different altitudes, and to present a general plan of the broader
topographic features of the State. Owing to the small scale of the
map, it was necessary to omit such minor details as sink-holes, valleys
of small streams, narrow ridges and small, more or less, isolated ele-
vations. The U. S. Geological Survey has already published detailed
maps of certain parts of the peninsula, and to these the reader is
referred for local information.'
'Arredondo, Citra, Dunnellon. Ocala, Panasoffkee, Tsala Apopka and
Williston sheets.. .







SECOND ANNUAL REPORT-TOPOGRAIPHY AND DRAINAGE.


An examination of the map will show that the southern part of
the peninsula, comprising an area about 150 miles long and averaging
over 100 miles in width, has an altitude of less than fifty feet above
sea level. In addition to this large area, there are narrow strips of
lowland along the Atlantic and Gulf coasts. It is also apparent that
the valleys of the streams do not rise above the 50-foot contour for
a considerable distance from the coast, and in one case-the St. Johns
River-the stream is nowhere more than thirty feet above tide.
The uplands of the peninsula and adjacent part of north Florida
are separated into two more or less distinct parts by the Ocklawaha
River. Beginning southeast of Arcadia, a belt of high land extends
northward to Summit, in Marion County. This area, which is very
irregular in shape, separates the Kissimmee River drainage from the
various streams to the westward. In this upland at Lakeland, Brooks-
ville, and several other points, the surface is known to rise more
than 200 feet above sea level.
Another broad irregular upland extends from just north of the
(cklawaha River to the Georgia-Florida line. This area forms the
divide between the Atlantic and Gulf drainage basins, and includes a
considerable tract which rises above 150 feet. Its narrowest part is
along the western boundaries of Clay and Duval Counties where it
forms the long north-south divide known as "Trail Ridge." This
upland includes Lake City with a altitude of 201 feet above tide and
Highland on the "Trail Ridge" with an altitude of 210 feet above the
same datum place. Near the Georgia line the upland broadens into
the Okefinokee swamp which occupies a large area in Georgia, but
extends only a short distance into Florida. The western slope of this
highland is cut by the Santa Fe River and its tributaries, while its
eastern slope is deeply dissected by the tributaries of the St. Johns
and St. Marys Rivers.
Near the State line in the northern and western parts of Florida
there is a narrow upland which has been deeply eroded by the
various streams which cross it. On its seaward side this highland
often descends rather abruptly to the low coastal region. The highest
points in this region are near the northern line of the State where
considerable areas rise above the 250-foot contour. Notable examples
of this upland are seen in Gadsden County and in the counties west
of the Choctawhatchee River; and Tallahassee. the capital of the
State, with an altitude of about 200 feet above tide, is situated upon
a remnant which has been isolated by erosion. East of the Apalachi-
cola River, the railroad stations at Monticello, Midway and Quincy
are all reported to be over 200 feet above sea level. West of the Apa-
lachicola River, between Argyle and Holt, on the Louisville and
Nashville Railroad, and at various points on the Yell.-n H', K-.n11






FLORIDA STATE GEOLOGICAL SURVEY.


road, the profiles show that there are considerable tracts of land which
rise above the 200-foot contour, while Argyle, De Funiak Springs
and Mossyhead are all above 250 feet-the last named being 264 feet
above tide. It appears probable that at some localities near the Ala-
bama line the surface may rise somewhat higher and small areas may
exceed 300 feet.
Rivers:-The drainage history of Florida has been somewhat
complex, and the changes in relative positions of land and sea which
have affected the stream are so closely interwoven with the general
geologic and physiographic history that their full discussion is left for
a subsequent report. At this time it is only necessary to note the
general character of the streams and state briefly the factors which
have produced the existing conditions. Some of the rivers are con-
fined to the coastal lowlands where they assumed their courses in
consequence of the initial slope of the land as it emerged from beneath
the sea, and they are therefore known as consequent streams. Their
positions are dependent upon the original slope of the surficial sand,
and their channels are frequently winding. Wherever there were de-
pressions in the sands, lakes were formed and some of the consequent
streams consist of a chain of such lakes joined by more or less well
defined channels. To this class belongs the Kissinmmee-Caloosahatchee
system with its numerous lakes.
Wherever the consequent streams have removed the thin mantle
of surficial sand and cut into the older formations they belong to the
class known as superimposed streams. Thus the Caloosahatchee
River which in parts of its course has eroded a channel through the
surface formations and into the underlying Pliocene and possibly
Miocene marls, is superimposed upon the older formations. In like
manner the St. Johns River north of Sanford has been superimposed
upon the Pliocene and probably the Miocene rocks. The Manatee and
Aucilla Rivers have in parts of their courses been superimposed upon
the Oligocene formations. There are in Florida many other examples
of consequent and superimposed streams and many of the rivers such
as the St. Johns are in part consequent and in part superimposed.
The rivers which cross both the older and younger geological
formations existed before the deposition of the sands which form the
surface of the lowlands. At that time they entered the sea at the
edge of the present highland belt. Where they cross the highland
these streams have broad, deep valleys floored with a deposit of al-
luvium and are often bordered by prominent bluffs. In their courses
across the uplands, they take a direction which was determined by
the slope of the surface; but they have usually removed the surficial
formations and cut deeply into the older rocks upon which they are
superimposed.






SECOND ANNUAL REPORT-TOPOGRAPHY AND DRAINAGE.


As the coastal belt emerged from the sea by successive additions
to its landward margin these streams gradually extended their chan-
nels across this new land and hence became in part what is commonly
known as extended streams. On the coastal belt they flow in broad.
shallow trenches bordered by low banks of sand, and in some cases
they have removed the Pleistocene sand and eroded channels in the
underlying limestones and marls. The most important extended
streams of the State are the Escambia, Black Water, Yellow, Choc-
tawhatchee, Apalachicola, Ocklocknee. Aucilla, Withlacoochee, Hills-
boro, Peace and St. Marys Rivers. With the possible exception of
the Escambia River all of these streams are in part superimposed upon
the Pliocene or older geological formations.
After the deposition of the younger geological formations and the
extension of the streams across the newly emerged land there came
a slight submergence which caused a shortening of the streams and
permitted the sea water to enter the river channels for a distance of
several miles from the coast. In this way the lower parts of the
stream valleys have been transformed into estuaries which contain
brackish water and are affected by the tides. The length of these
estuaries or tidal portions of the rivers varies in the different
streams, and even in a single river it may vary with the strength and
direction of the wind. Strong on-shore winds raise the height of
the water and force the sea water farther up-stream, while off-shore
winds have an opposite effect.
Lakes and Swamps:-Although the State of Florida is crossed by
many large rivers there are numerous tracts of land which are very
imperfectly drained and are occupied by lakes or swamps. The lake
region will be more fully discussed on subsequent pages, and it is
sufficient to note that lakes are very numerous, some of them being
of considerable size. The swamps are of varying size, from a few
rods to many miles in diameter. The most notable undrained area is
in the southern part of the peninsula where the Everglades and ad-
jacent lowlands form a nearly impenetrable wilderness. In this low-.
land tract lies Lake Okeechobee, which is one of the largest and most
interesting lakes in the South Atlantic States. According to the
measurements cited by Sanford the Everglades nowhere rise more
than 22.4 feet above sea level, and the surface has such a gentle slope
that the water which falls during the rainy season forms broad shal-
low ponds and marshes which afford excellent opportunity for the
growth of saw-grass and other aquatic plants. These plants by their
partial decay under water have formed peat and muck deposits several
feet in thickness.
The smaller swamps and marshes occur in all parts of the State,
but they are p" ...i I ..I numerous in the belt of lowland which borders






FLORIDA STATE GEOLOGICAL SURVEY.


the coast, and they become smaller and less numerous in the high-
lands which border the north line of the State. In the coastal belt
there are many small lakes and ponds, some of them permanent, but
most of them lasting only during the rainy season. They seldom ex-
ceed two or three feet in depth and appear to occupy shallow depres-
sions in the surface of the sand.
In the central part of the peninsula and in some localities near
the northern boundary of the State there are lakes and swamps which
appear to be the result either of unequal deposition of the surface
sands or of solution of the subjacent limestone and consequent lower-
ing of the surface in the manner described under Caverns. Some of
these lakes are shallow and resemble those of the coastal belt, but
others are deep basins partially or wholly enclosed by a rim of rock.
The smaller swamps often contain considerable deposits of peat or
muck.
LAKE REGION.

The lake region occupies a large part of the highland in the central
part of the peninsula, but similar topography is to be found in both
North and West Florida. The southern boundary of the lake region
is not sharply defined and it comprises two more or less distinct areas
consisting of the lakes in the elevated portion of the peninsula which
usually have rock basins and those of the coastal and southern low-
lands which occupy shallow depressions in the sand. While the areas
characterized by these two types are more or less distinct, there are
many lakes in the highlands which may be due to depressions in the
sand and there are small lakes in the lowlands which are known to
occupy rock basins. The highland area of the peninsula where rock
basins predominate has commonly been known as the Lake Region,
and for convenience this meaning is retained.
The Lake Region comprises a type of topography common to all
Limestone areas which have been sufficiently elevated to permit the
formation of large underground streams. The character of the sur-
face is well shown by the Williston topographic sheet of the U. S.
Geological Survey. The numerous depressions shown in the accom-
panying text figure, which is taken from this map, are known as
sink-holes and, in order to understand their origin, it is necessary
to consider the development of the underground drainage.
Caverns:-This region is underlain, at no great depth, by several
hundred feet of porous limestones of Vicksburg age. Where surface
water -earing carbonic acid. derived from decaying organic matter,
enters this rock, it gradually dissolves the limestone and thus forms
underground channels.






SECOND -ANNUAL REPORT-TOPOGRAPIY AND DRAINAGE.


A large part of the mineral matter which is thus removed by the
underground water is carried to the surface; and, entering the rivers,
is transported to the sea. In an earlier report by this Survey,1 there is
an estimate of the amount of solid matter removed in this manner.
The quantities given were based upon a consideration of the amount


















0 2 __3 wiles














Fig. 1. Map showing sink holes.
of mineral matter removed in solution in eight of the large springs
of the State. These springs emerge from caverns in the underlying
limestone and they are fed by the rainfall upon the surrounding area.
The percentage of mineral matter in solution was determined by an-
alysis and the volume of flow was estimated. By this method Dr.
Sellards estimated that Silver Spring brought to .the surface 340
pounds of mineral matter per minute. While the quantity of matter
in solution in the water of the other springs varied it was in all cases
Sellards, E. H., A Preliminary Report on the Underground Water Supply
of Central Florida, Fla. State Geol. Survey, Bull. 1, 1908, pp. 47-48.
2g Digitized by GOO gI






* FLORIDA STATE GEOLOGICAL SURVEY.


large. With a conservative estimate of the average mineral content
of the spring water (219 parts per million) and the assumption that
alcut one-half' the rainfall of Florida entered the earth and removed
this amount of material, Dr. Sellards reached the conclusion that the
rate of solution was sufficient to remove, in the limestone section
of Florida, about 400 tons per square mile annually. If evenly dis-
tributed, this would lower the surface of the limestone about one foot
in five or six thousand years. The concentration of this solution along
certain beds oi channels of active circulation would permit the forma-
tion of large underground passages in a comparatively short period
of geological time. These channels, known as caverns, are sometimes
hundreds of feet in diameter and several miles in length. A level sur-
face and a porous soil favor the development of caverns because most
of the rainfall sinks into the earth instead of flowing off over the
surface. In the past the region under discussion appears to have fur-
nished an excellent opportunity for the formation of caverns because
its surface was comparatively level and covered by a mantle of porous
material.
Sink Holes:- As solution progressed the cavern roofs became
weakened at various points and collapsed, forming the depressions
known as sink-holes. In some areas these depressions are so numer-
ous that they occupy a large part of the surface and give the region
its characteristic topography. Splendid examples of ancient sinks
such as the Devil's Mill Hopper are to be found in various parts of
the State, and instances where sinks have been formed by the collapse
of cavern roofs within the memory of persons now living are known
in different parts of the Lake Region. A good example of a recently
formed sink is to be seen on the road between High Springs and the
"Sink" of the Santa Fe River. In the phosphate region a large
quantity of water, which has been used in mining operations, is al-
lowed to enter the ground. That this water frequently has a notice-
able effect in weakening the roofs of the underground drainage chan-
nels is shown by the following quotation from the unpublished notes
of Geo. H. Eldridge:
Sinks have frequently been formed since the mining of phosphate has been
undertaken in the vicinities of the settling ponds, or in the line of drainage from
the mine washers. The writer has passed over an apparently solid road in the
morning to return at night to find in his way a chasm fully 40 feet across, earth,
shrubs and trees engulfed, and with the water pouring down to an underground
passage in the weirdest way. Again, at one of the Southampton mines, the
floor of the old pit, together with an adjoining area of the sand overburden, has
sunk several feet with a rift in the earth 4 or 5 feet across in which is shown
on the one side the smooth walls of lime spires and connecting ridge; on the

'Ibid. p. 16.







SECOND ANNUAL REPORT-TOPOGRAPHY AND DRAINAGE.


other the materials that slipped away, no longer being able to retain their pur-
chase on the walls, their support below having been. removed.
If the bottom of the sink does not contain an opening, the water
which accumulates after a rainfall will usually escape to the under-
ground stream by seepage; but where the amount of rainfall is too
great to be carried away in this manner, lakes or ponds accumulate.
The level of the standing water in such cases fluctuates, rising after
each rainfall and gradually sinking during dry weather. There are
hundreds of lakes in Florida which appear to belong to this class.
Some of the sinks have an opening in the bottom which connects di-
rectly with the underground stream. Into these openings the surface
streams plunge, carrying their loads of sediment and other debris.
This sediment probably aids the underground stream in enlarging its
channel by mechanical wear, but sometimes it accumulates in such
quantities as partially or even wholly to close the passage. In such
cases the surface water remains in the sink to form a lake. Ex-
amples of open sinks receiving the discharge of surface streams are
common, conspicuous among them being the sink of the Santa Fe
River, the sink of the Chipola River, the Lake sink in Jefferson
County and Alachua sink near Gainesville. Alachua sink is import-
ant because it illustrates some of the changes through which sink-
holes may pass. This sink receives the drainage of a large stream
which crosses a prairie (Payne's Prairie). In the early history of
the State this region appears to have been in about the same condition
as it is today.' Later, owing to the outlet becoming closed,2 perhaps
by logs and other rubbish thrown into the stream, a large lake formed
in the depression. About 1891, the sink reopened and the basin was
drained, effectually ending the steamboat traffic which had developed
on the lake.
In some parts of the caverns the water which enters through the
openings in the limestone evaporates, leaving a deposit of calcium
carbonate. By gradual accretion these deposits may form large pend-
ants-stalactites-hanging from the roof or walls. When the water
falls to the floor of the cavern and evaporates, it often forms projec-
tions known as stalagmites. The deposits in caverns are frequently
highly ornamental and form the chief attraction for visitors.
Sometimes the underground streams form new passages and aban-
don portions of their old channels. The abandoned channels are the
caverns which are visited by travelers. In Florida, only a few cav-
erns have been explored and none are reported to be highly orna-
mented. The most important caverns which were noted during the
'Bartram, William, Travels, 1791, pp. 187 et seq.
'Dall, Wm. H., Neocene of North America, U. S. Geol. Survey Bull. 84,
1892, pp. 94-96.. ..






FLORIDA STATE GEOLOGICAL SURVEY.


field work are located near Marianna, Ocala and Alachua. The one
near Alachua is known as Warren cave and is said to be well worth
visiting.
Natural Bridges: -Where the underground stream emerges it
forms a spring and as the roof of the cavern falls it leaves an open
channel through which the spring drains to some surface stream. By
a continuation of this process the underground stream is transformed
into a surface stream. Where a segment of the roof of the under-
ground channel remains after the parts above and below have fallen,
a natural bridge results. In Florida natural bridges may also be








Fig. 2. A D represents the bed of a stream flowing across limestone. The
development of an underground channel from X to Y caused the stream to
abandon its surface channel.
formed in another manner. In text figure 2 A D represents a
longitudinal section of a surface stream flowing toward D and hav-
ing for its bed the limestone A B C D. A'passage, X Y, formed by
solution, may permit some of the river water to take a course through
the underlying limestone. As this channel is gradually enlarged by
solution and mechanical wear, more river water passes through it.
Finally, the surface channel may be unoccupied except during high
water, or if the underground passage is large enough the surface
channel may be entirely abandoned. A surface channel may also be
produced across a natural bridge whenever the underground passage
is partially obstructed.
There are many natural bridges in Florida. small ones being re-
ported near Homosassa, north of Clarksville, in northern Walton
County, and in many other localities. Large natural bridges occur
on the Chipola River above Marianna, on the St. Marks River, south-
east of Tallahassee, on the Santa Fe River, northeast of High Springs,'
and on several other rivers. The natural bridge on the Chipola River
is submerged during high water, and a broad shallow surface channel
which crosses the one near High Springs is said to carry a portion of
the flood waters of the Santa Fe River. The breadth of the surface
channel near High Springs suggests that the natural bridge of the
Santa Fe River may have been formed by the second method outlined

'See Fig. 1, Plate viii. Digitized by Goo Ie
Digitized by jOO lC







SECOND ANNUAL REPORT-TOPOGRAPHY AND DRAINAGE.


above. The natural bridge of the Chipola River was submerged at
the time the field work was done in that vicinity, so that no observa-
tions could be made. However, the broad valley of the river above
the bridge indicates that the upper part of the Chipola River has been
a surface stream for a long period. Since natural bridges in such
rocks are not apt to endure for long periods it appears probable that
this one may also have been formed by the second method.
Sand Dunes:-A large part of the surface of Florida is covered
by a few feet of Pleistocene sand. In the Lake Region this sand has
sometimes reduced the original inequalities of the surface. In other
cases the formation of sand dunes and ridges has increased the top-
ographic irregularities. However, the dunes and ridges are seldom
more than a few feet in height, and hence their effect on the topog-
raphy is not very marked.
Springs: The great development of underground drainage in
many parts of the State has already been mentioned. Where the
streams emerge from their subterranean channels they form springs.
It is impossible to make any exact estimate of the number of springs
in the State, and it is perhaps sufficient to say that they are exceedingly
numerous. They vary in size from mere seeps to springs which give
rise to creeks and rivers large enough to float good-sized passenger
and freight steamers. The best known and largest of these springs
is the Silver Spring in Marion County, which gives rise to a large
stream of remarkable clearness and beauty. The water emerges from
the basin which probably attains a depth of at least thirty-five feet,
and the stream, Silver Spring Run, that flows from this basin, has
an average width of about fifty feet and a minimum depth in the
center of the channel of more than nine feet. The water is so clear
that it is possible to discern objects lying on the bottom and to observe
the fish and other aquatic animals. Among the other large springs of
the region are Wekiva Spring, in Orange County, the source of the
river of the same name: Sulphur Spring, near Tampa; Suwanee
Sulphur Spring, White Sulphur Spring, Blue Spring, near Juliette
Station; Blue Spring, near Orange City Junction; Green Cove Spring,
on the St. Johns; Wakulla Spring, near Tallahassee; Itchetucknee
Spring, near Fort White; Poe Spring near High Springs; Crystal
River Springs which give rise to the Crystal River; Weekiwachee
Spring, near Bayport, and Newland Spring, near Falmouth. All of
these springs are well known and many of them are very large. They
are supplied with water by the underlying limestone which is every-
where so porous and cavernous that it yields large supplies.
A spring at Tarpon Springs is worthy of special mention because
it appears to be in part supplied with water from a -m, ill 1,.- T'h






FLORIDA STATE GEOLOGICAL SURVEY.


water emerges at the bottom of the bay a few feet below mean tide
level. On the opposite side of the town is a small lake with no sur-
face outlet and apparently occupying a sinkhole. Usually the flow of
this spring is comparatively insignificant, but at times the discharge
is enormous. Observations made upon the lake just before and after
one of these outbursts of the spring appear to show that the lake dis-
charges water into the spring through some underground channel,
for the surface of the lake is said to have been lowered several inches
while the spring was flowing rapidly.
Aside from the large springs mentioned above there are many
others which yield quantities of water, and springs of moderate size
are to be found in nearly all parts of the State. Some of the smaller
springs are supplied with water from the superficial sands, but many
of them derive their supplies from the limestones.

NORTH AND WEST FLORIDA.

In West Florida and in parts of peninsular and northern Florida,
the surface configuration has been largely determined by the erosion
of surface streams. However, sink-hole topography is common as
far west as Walton County, and many of the depressions are occupied
by small lakes.
Erosion Features: From Leon County westward the major
streams cross the upland in wide level-floored valleys bordered by
well-defined bluffs. The depth of these valleys is due to the erosive
action and the width to the meandering of the streams. The valleys
usually contain a deposit of sand and mud, which rises but little above
the level of the streams and is partially overflowed when the rivers
are high.
The small streams of the uplands flow in narrow valleys having
steep walls and high gradients. In most cases erosion has not ex-
tended far from the main streams, and hence there are many com-
paratively level areas which form the divides between the principal
rivers. On approaching the rivers, the areas of level land become
smaller and the number and depth of the valleys increase until the
surface is largely reduced to steep slopes. It is also worthy of note
that the amount of dissection which the upland has suffered increases
toward the south. Thus the largest level tracts of upland are usually
found near the northern line of the State. At its southern edge, the
upland sometimes descends abruptly to the coastal belt which borders
the Gulf of Mexico. In some cases, however, the transition to the
coastal lowlands is by a gradual slope.
Lakes:-The uplands are usually covered by a few feet of white
Pleistocene sand which masks the minor inequalities of tli erosion






SECOND ANNUAL REPORT-TOPOGRAPHY AND DRAINAGE.


topography. Moreover, it is frequently difficult to determine whether
shallow depressions are sink-holes or are merely due to irregularities
in the surface of the sand. However, in the case of such deep de-
pressions as the lake at De Funiak Springs, the sink-hole origin of
the basin appears to be unquestionable.
Sand Dunes: Sand dunes and ridges are common, especially
along the southern edge of the uplands, but they are seldom more than
a few feet in height. Wind blown sands are probably much more
widespread than is indicated by the surface topography. However,
at the present time, the heavy precipitation, together with abundant
vegetation, prevents the development of an extensive dune topography.

COASTAL REGION.

Streams and Ponds:-The coastal region of Florida comprises a
belt of lowland which seldom rises above the 50-foot contour, and
over large areas its surface is only a few feet above high tide. Its
emergence from the sea took place after the drainage of the uplands
had been well developed, and the rivers gradually extended their
channels across it as new areas were added to the land. The Pleisto-
cene sand which forms a large part of the surface has a gentle slope
toward the sea and is occasionally crossed by small streams which
flow in shallow valleys. Minor irregularities in the surface of the
sand have given rise to shallow lakes and ponds which cover large
areas during the rainy season. The difference in elevation between
the bottoms of some of these ponds and the surrounding areas is fre-
quently less than two feet.
Ridges:-Scattered throughout the coastal region are small areas
of higher land which in some places resemble sand ridges and in other
places are very irregular in shape. In some places they are found to
contain a core of rock which is covered by a thin mantle of sand, but
frequently they appear to Le entirely composed of sand. These areas
represent the higher parts of the original sea floor, and their position
was determined by the inequalities in the surface of the underlying
rock or by unequal deposition of the sands.
Terraces: In the valley of the St. Johns River and at various
points along the coast, the sands form a well defined terrace which
rises twenty to thirty feet above tide. This terrace was observed at
several localities and it appears to be the result of wave action during
the Pleistocene. Similar terraces occur along the other streams of
Florida and there is some evidence that there are others at higher
levels; lut their satisfactory discrimination will require a more de-
tailed study than could be made in the time allotted to the i 1.1 work.





FLORIDA STATE GEOLOGICAL SURVEY.


SHORE LINES.

The State of Florida has an extensive coast line, presenting a great
variety of topographic forms. The various agents which have been
important in producing the coastal forms are: the waves, the tides, the
shore currents, and the growth of organisms, chiefly corals. The
configuration of the shore lines is dependent upon the relative im-
portance of these agents.
Coral Reefs:-The coral reefs are restricted to an area near the
southern end of the peninsula; and it was to this area that much of
the earlier geological work was devoted. In a subsequent chapter Mr.
Samuel Sanford will discuss the formation of the keys and the ad-
jacent portion of the mainland in the light of his recent studies in that
region. At present it is only necessary to call attention to the fact
that coral reefs have been of minor importance in the development of
the peninsula of Florida: in fact, there appears to be no reason to
suppose that reefs have existed on the west coast or north of the
north line of Palm Beach County on the east coast.
Submerged Continental Border:-Reference to the charts of the
U. S. Coast and Geodetic Survey shows that the depth of the water
along the Florida coast is seldom more than a few feet. As the
distance from the land increases, the water gradually deepens over
this submerged continental border and there is an abrupt descent to
deep sea bottom at a considerable distance from the land. This
marginal shelf is to be regarded as a part of the continent now covered
by the sea, and it has probably been in part, if not wholly, above water
during some period of geological history.
Bars:-In the shallow water at some distance from the shore, the
waves gradually build. bars which rise nearly to the surface of the
water. The material for the construction of these bars is derived
from the sea bottom, and hence they vary with the character of the
shore. At the present time the prevailing materials on both the east
and west coasts is sand, though there is often a considerable admixture
of shells. For this reason the bars which are now forming consist
largely of sand with a small proportion of shell fragments. In com-
paratively recent geologic time the beach materials on some parts of
the coast appear to have been largely shells and these were built into
bars which were afterward cemented to form coquina. Occasional
layers of sand and a considerable percentage of silica in the coquina
show that terrigenous material was never entirely absent, though it
was often of minor importance. In the shallow water along the ex-
posed shores, either of the mainland or islands, currents are formed
which transport the beach materials and build them into a variety of
forms. One of the common types to be found on the Florida coast is







SECOND ANNUAL REPORT-TOPOGRAPHY AND DRAINAGE.


the bar which is built across the entrance to a bay. Such bars are to
be found at the entrance of all the bays, and their removal is one of
the important problems which confronts the army engineers in their
endeavor to nake the rivers and harbors accessible to shipping.
On the east coast where the prevailing currents move southward,
the bars are commcnly extended by additions to their southern ends.
On the Gulf coast of the peninsula the dominant currents appear to be
in the opposite direction and the bars are usually built by extensive
additions to their northern ends. The dominant current on the coast
of West Florida appears to move toward the west, though an east-
ward current of some importance may be inferred from the position
of the bar at the entrance to St. Andrews Bay. Bars of the kind de-
scribed above are to be seen along the entire coast of Florida wherever
there are large bays.
Sounds: Behind the shore bars on the east coast are narrow
bodies of shallow water which are commonly known as rivers, though
they might more appropriately be termed sounds. To this class be-
long such bodies of water as the Halifax and Indian Rivers. As the
sounds become more nearly surrounded by the growing bars they
are changed into lagoons which are in turn gradually filled with silt
and thus transformed into marshes. Mosquito lagoon and Lake
Worth on the east coast are excellent examples of lagoons, and there
are numerous marshes along both the east and west coasts.
About twenty years ago an attempt was made to open a passage
for steamship navigation by deepening the sounds and lagoons. This
plan was successful, but in recent years the channels have been allowed
to become obstructed by sand bars and oyster reefs. In the last few
years interest in this "inside" channel has been revived, and it is now
proposed to extend the passage northward to New Jersey.
Inlets: Where drainage from the land enters a sound or par-
tially enclosed bay, the water escapes through a narrow passage in
the bar known as an inlet. As the bars are built under the influence
of a prevailing current, the inlet is gradually shifted in the direction
of growth. After a- time the opening becomes so obstructed that a
new inlet is formed by the action of high water. Usually the inlets
are formed near the head of the bar and their direction of movement
on the Atlantic coast is southward and on the Gulf coast northward
or westward. At Jupiter on the east coast an opening is sometimes
dredged near the north end of the bar and this opening is gradually
shifted toward the south. It has been found that the inlet remains
open much longer when the opening is made toward the northern end
of the bar than when it is located farther south.
Tidal Runways:-At ordinary high tide the level of the water in
the bays and sounds is raised from one to two feet -ihnv th, r,.r,;,i







FLORIDA STATE GEOLOGICAL SURVEY.


low water level. If, at the same time, a strong wind is blowing to-
ward the land the water rises much higher. When the tide recedes, a
seaward current is formed which scours the bottom and sides of the
channels. Frequently the water pours through some low gap in a
shore bar, thus helping to form a passage. Many of the inlets across
the Florida bars are formed in this way. To the erosive action de-
scribed above, Mr. F. P. Gulliver' has given the name of "tidal scour,"
and he thinks that the channels near Cedar Keys present an example
of tidal runways produced by tidal scour, and he designates these run-
ways as the "Western Florida Type." At the mouth of the St. Johns
River and elsewhere along the South Atlantic and Gulf coasts the
army engineers have constructed dams to narrow the runway so that
the effect of the tidal scour will keep open a channel deep enough to
permit the entrance of large vessels. Examples of tidal scour along
the keys and the southern part of the Florida peninsula will be dis-
cussed by Mr. Sanford.
Capes:-Many of the important capes of Florida appear to have
teen built of sand deposited by the currents moving along the shore.
Cape Canaveral on the east coast was formed where the easterly trend
of the coast caused the southward moving current to move outward
from the coast into the deeper water which checked its velocity and
caused it to deposit some of its load of sand. From the outward end
of the cape there projects a long, narrow spit of sand which rises
nearly to the surface of the water. The seaward end of the spit is
often bent into a hook by the action of the current.
On the west coast the northward moving current encounters the
islands near the west end of St. Vincent Sound, and turning westward
forms Cape San Bias. Cape St. George at the western end of the
island of the same name, and Southwest Cape, west of Apalachee
Bay, appear to have been formed in a similar manner. All of these
capes are gradually being extended seaward by the continual addition
of more material transported along shore by the currents. In addition
to the capes mentioned above, there are many minor projections usu-
ally known as points, which originated in practically the same manner
as the larger capes. In 18.I8 Dr. F. P. Gulliver2 studied the origin
of Capes Canaveral and San Bias and designated them "current cus-
pate forelands."

SShoreline topography, Proc. Amer. Acad. of Arts and Sciences, Vol. 24.
'Gulliver. F. P. Shoreline topography. Proc. Am. Acad. of Arts and
Sciences, vol. 24, pp. 180-181.







SECOND ANNUAL REPORT-SOILS.


SOILS.

ORIGIN.

The soils of Florida are almost all based upon the sandy forma-
tions of Pliocene and Pleistocene age; and, since the gray Pleistocene
sand is the most widespread of the surface deposits, it naturally
forms the soils over the greater portion of the State. The Lafayette
soils occupy considerable areas in northern and western Florida and
they often form the subsoil where the Pleistocene sands are thin.
The Alachra clay and the Pleistocene marls are so thinly covered in
some parts of Peninsular and West Florida that they form a part of
the subsoil. In some areas, where erosion has been especially active
toth Pliocene and Pleistocene deposits have been removed, leaving
the older geological formation exposed to form the soils; but such
areas are of limited extent, and are comparatively unimportant. In a
few localities residual materials formed by the weathering of the
Oligocene forn-aticns lie so near the surface that they form a more
or less important part of the soil or subsoil.
Other types of soil occupy a large area in the southern part of the
peninsula and smaller areas in various other parts of the State. These
are the peat and muck soils which have their greatest development in
the Everglades, but are found in many other localities where swamps
exist. They consist of organic matter mixed with more or less in-
organic material, such as sand and clay. These soils are of recent
origin and are still being formed, especially over a large area south
of Lake Okeechobee where the surface is very low and flat and the
drainage imperfect.
The Pleistocene sands form the soil in nearly all of peninsular
Florida and extend over a part of the uplands in northern and western
Florida. Their occurrence in detail may be gathered from the descrip-
tion of the distribution of the Pleistocene formations. The soils of
the Lafayette formation are largely confined to the upland areas near
the northern boundary of the State. They do not form large, un-
broken tracts, but occur in more or less isolated areas where the post-
Pliocene sands are absent. In many localities the overlying sands are
so thin that the Lafayette deposits form an essential part of either the
soil or the subsoil, even where the surface materials are younger.
This is the condition in a part of the important tobacco producing area
in Gadsden County.
Pleistocene marls and coquina, in a more or less decomposed state,
form the subsoil at various places along the east coast and along the
west coast south of Bradentown. These marl and coquina beds are
discussed under the head of geology, and their ,I;:trbiti.i:,n. ',-, far Ia-






FLORIDA STATE GEOLOGICAL SURVEY.


it is now known, is given. However, it should be remembered that
the areas where these Pleistocene beds lie near enough to be consid-
ered part of the soil are much more restricted than is their geological
distribution.
In the central part of the peninsula, especially, northwest of Gaines-
ville, the Alachua clay is so near the surface that it forms a part of
the subsoil, but does not enter into the formation of the surface soil.
Over much of the area where this formation occurs, it is too deeply
buried to be considered a part of the soil.
On the north bank of the Manatee River, in the vicinity of Ellen-
ton, there are some areas of land. valuable for truck gardening, where
the residual clays left by the solution of the limestone of the Tampa
formation form very good soils. In some places, these clays contain
more or less Pleistocene sand, and angular or sub-angular fragments
of flint are -common. There are doubtless other localities where the
residual products of this limestone are near enough to the surface to
form part of the soils, but their distribution is not yet known. The
limestones of the Chattahoochee formation and the Vicksburg group
may form parts of the soils in a few localities, but they are usually
too deeply buried beneath the younger geological formations to be
important in soil formation. It is the proximity to the surface of
nmarls or residual products of the Vicksburg group which is regarded
as the source of the fertility of many of the "hammock" lands near
the west coast. It is doubtless the presence of such materials near the
surface which accounts for the excellent growth of timber in places
where the surface soil is very poor.

CLASSIFICATION.

In 189), Prof. Milton Whitney made a general examination of
the Florida soils and classified them as follows:
The principal types of soils examined were the first, second and third quality
of high pine land; the pine flats or so-called "flat woods"; the light hammock,
the gray or heavy hammock, the mixed land, the heavy marl hammock; the
pineapple land: the Etonia scrub, the spruce-pine scrub; and the Lafayette
formation.
Since the publication of Prof. Whitney's report detailed soil sur-
veys have been made in the vicinity of Gainesville, and in Jefferson,
Leon. Gadsden and Escambia Counties. In the detailed work, the
soils were classified by their physical properties, origin and topog-
raphy. In this classification texture is the most important character-
istic. In Florida, the principal types of soils recognized are sands.
fine sands, sandy loam, and fine sandy loams. Subordinate types are
loams, silt loams, clays, muck and meadow. These types have. v,~h






SECOND ANNUAL REPORT-SOILS.


some exceptions, been grouped into three series and correlated with
similar soils elsewhere in the coastal plain. Since a detailed descrip-
tion of the soils cannot be given in this report, no attempt will be
made to discuss the various series represented in the State. Aside
from the general types of soils which have been grouped into series
and correlated with similar soils outside of the State, there are the
Gainesville sand, the Gadsden sand' and some other types which have
not yet been correlated.
The clay and loam soils of Florida cover a very limited area, and
are not of great importance. The clay soils are largely restricted to
small tracts in the neighborhood of streams and are not tilled. In this
connection, it should be borne in mind that much of what is commonly
called clay in northern and western Florida is to be classified as a
sandy loam, because, while it is more or less plastic, sand is the most
important constituent. The greater part of Florida has either a sandy
or sandy loam soil, and while these soils may be subdivided into a
large number of types, they possess, as a whole, certain general char-
acteristics. When brought under cultivation, they commonly have a
low natural productivity, but they respond quickly to proper treat-
ment, and can be made to produce large crops which grow rapidly
and mature early. These characteristics, when linked with a sub-
tropical climate, make the production of early fruits and vegetables
very profitable. In order to procure the best results, it is necessary
to exercise skill and judgment in the treatment of the soils, and, in
some instances, considerable money must be expended for fertilizers.
There is apt to be a deficiency of moisture on some of the sands and
sandy loams, and hence irrigation is sometimes practiced.
Fertilizers are used in nearly all parts of the State, the amount and
kind of fertilizer required in the different localities being governed by
the nature of the crops grown and the experience of the most success-
ful farmers. A striking example of the productivity of a sandy soil
properly tilled is furnished by the yield of pineapples which are grown
upon the ridge of sand near Fort Pierce. The value of barnyard
refuse and legumes as fertilizers is recognized in some localities, but
their use should be much more extensive. Some recent experiments
of the Department of Agriculture2 are of interest, since they show
that lime, which is not generally used on Florida soils, may add greatly

'Names applied by Bureau of Soils, of the Department of Agriculture, to
certain -soils in this region; not geologic subdivision. Soil survey of the Gaines-
ville area, Florida; soil survey of Gadsden county, Florida, U. S. Dept. Agricul-
ture Field Operations Bureau of Soils, 1904, pp. 269-286.
'Soil survey of Escambia county, Florida, Field Operations of the Bureau
of Soils, U. S. Department of Agriculture, 1906, pp. 348. See also "Soil Studies"
by the Florida State Experiment Station, Bulletins 87 and 93.






FLORIDA STATE GEOLOGICAL SURVEY.


to the productiveness of certain types of the sand and sandy loam soils.
The peat and muck soils of Florida have not been extensively used
because they are in. swampy areas which require drainage. Extensive
drainage operations are in progress in the Everglades, and, if these
are continued, large areas of peat soil will be available for cultivation.
The natural productivity of the peat and muck soils of Florida has
seldom been determined, but, judging from the experience of farmers
in other States, it is safe to predict that the Everglade soils are
destined to take rank among the best lands of the State for the pro-
duction of certain crops. Moreover, experience in several other
States has shown that such soils seldom require the addition of com-
plete fertilizers such as are used on sandy soils. In fact, the addition
of small quantities of salts of potassium should usually be sufficient to
cause a peat or muck soil to produce good crops, though possibly, in
some cases, the addition of phosphates would be necessary. These
facts are important because it will cost much less to fertilize the peat
and muck soils than is now -being expended on the sandy soils.

STRUCTURE.

One of earliest discussions of the structure of Florida was written
by Johnson.1 in 1888. Though he was hampered by lack of detailed
knowledge of the stratigraphy of the State. Johnson presented con-
siderable evidence to show that the peninsula is a broad anticline. The
conclusion reached by him was, in a general way, the same as that of
several subsequent writers. His paper is accompanied by a section of
the strata across the northern end of the peninsula showing a broad
arch with the apex in the vicinity of Gainesville. The location of the
crest of the arch was recognized by the sink-hole topography which
was thought to indicate the presence of "Eocene" limestone (Oligo-
cene, Vicksburg group) within less than 100 feet of the surface, and
the dips away from the central part of the peninsula were determined
by noting the presence of younger formations at the surface and by
the altitude of the Oligocene beds in wells at various points.
About two years after the appearance of Johnson's paper, Prof.
Shaler2 published a brief discussion of the topography of Florida, and
in the same article stated his ideas of the structure of the State. Prof.
Shaler appears to have regarded the peninsula as a broad arch which
he likened to the Cincinnati anticline:
The first question before us concerns the origin of the Florida uplift. It
will be observed that we have in the peninsula of Florida a very remarkable
'Johnson, L. C., Amer. Jour. Sci., 3d series, Vol. 36, 1888, pp. 230-236.
'Shaler, N. S., Topography of Florida, Bull. Mus. Comp. Zool., Vol. 16,
No. 7, 1890, pp. 139-156.







SECOND ANNUAL REPORT-STRUCTURE OF FLORIDA.


ridge, which has grown up from the sea-floor to the altitude of about five thou-
sand feet; and a somewhat similar elevation in the archipelago of the Bahama
Islands. Neither of these ridges has a mountainous character. Indeed, it is at
first sight difficult to find the analogues of these great anticlinal-like folds in
the existing structures of the land. They can hardly be classed with any of our
known table-lands, for the reason that such elevations are in all cases more or
less associated with definite mountain folding. The only similar structure which
is known to me is that exhibited in the "Cincinnati anticlinal," that well-known
ridge extending from near Columbus, Ohio, to Northern Alabama. This eleva-
tion in length and breadth may be compared to that of Florida, though it never
had more than one-half the height of the Floridian peninsula.
It should be remembered that there is to be included with the
peninsula the submerged plateau which borders it on either side and
extends out to the abysmal depths of the ocean, and when Prof.
Shaler speaks of a broad earth arch he includes in it not only the
land but this submarine plateau which in places extends over 150
miles beyond the coast and which descends steeply to profound depths.
In a later paper, Prof. Shalert reiterates the same view and states that
he regards Florida as a broad submarine fold, approximately 600
miles in length which has risen from a depth of about 5,000 feet.
In commenting on the hypothesis advanced by Prof. Shaler, Dr.
DalPl says:
In considering the topography of Florida, it has been customary among
geologists and others to speak of the "central ridge," "elevated axis," and in
the latest contribution to the subject Prof. Shaler regards Florida as "formed
of lowlands rising as a broad fold from the deep water on either side to a vast
ridge, the top of which is relatively very flat, there being no indication of true
mountain folding in any part of the area." In an extremely wide and general
sense, it is, of course, true that the peninsula forms a great fold, but in the
ordinary and literal meaning of the words this description conveys an inaccurate
idea of the structure of the region.
Dr. Dall regards the structure of Florida as characterized by low
folds approximately parallel to the general trend of the peninsula.
By means of railroad profiles he finds indications of two well defined
ridges, one near the Atlantic coast and another near the Gulf coast.
A third ridge is noted in the vicinity of Brooksville and Plant City.
The eastern ridge which forms the eastern boundary of the central
"lake basin" includes the well known Trail Ridge and was thought to
be composed of "Miocene" rocks. In this connection "Miocene" is
probably intended to include the Oligocene rocks belonging to th'e Apa-
lachicola group which were then known as Miocene. The western
ridge forms the western boundary of the central "lake basin" and

'Shaler, N. S., Relation of Mountain Growth to Formation of Continents.
Bull. Geol. Soc. Amer., Vol. 5, 1894, pp. 206.
Dall, Wm. H., Neocene of North America, Bull. U. S. Geol. Survey N-.
84, 1892, pp. 87.






FLORIDA STATE GEOLOGICAL SURVEY.


passes through Lakeland. The theories advanced by Dall and John-
son differ in one important point. Dall believes that the central
lake basin is a synclinal valley; Johnson holds that this region which
he designates as "high hammocks" or "lake region" represents the
eroded apex of a broad arch.
Considering the State of Florida as a whole, it is merely the south-
ern extension of the coastal plain, and its history has in general been
the same. Broadly speaking there are two distinct axes of uplift
which appear to extend in a general north-south direction. The out-
line of the Vicksburgian limestone west of the Apalachicola River indi-
cates a gentle uplift, and field observations show that this limestone
has there an altitude of about 75 to 100 feet over a considerable area.
From this uplift, the rock dips rapidly to the south and west, and
more gently, but still perceptibly, towards the southeast. Towards the
north and northeast it rises to form the basis of the highlands of south-
ern Georgia and Alabama, and then gives place to the underlying
Jackson, which outcrops farther north. The exact trend of the uplift
which brought the Vicksburg to its present altitude in west Florida is
not known, but it is probably to the east of north. The peninsular
portion of Florida represents a broad uplift such as was postulated by
Johnson and Shaler, and the comparison with the Cincinnati arch ap-
pears to be quite appropriate. The objection to the use of the term
"anticline" in connection with these broad uplifts is due to the fact
that most geologists are inclined to associate the word with narrower
archings of the strata, such as are common in the Appalachian or other
closely folded regions. By the use of the term "arch" it is hoped
that this objection will be removed. In the peninsula of Florida, the
arching of the beds has raised the lower Oligocene to an altitude of
more than 100 feet above tide over considerable areas from the vi-
cinity of Brooksville and Croom northward to and beyond Gainesville.
Live Oak and Lake City. Around the outcrops of the rocks belonging
to the Vicksburg group which have been exposed on account of the
erosion of this arch, are the exposures of the formations which com-
prise the Apalachicola group and younger beds. The rocks belonging
to the Apalachicola group occupy a broad belt from Sarasota north-
ward to the Georgia-Florida line, and extend westward to where they
are overlapped by the beds of Miocene age. On the eastern side of
the central uplift the Apalachicola group occupies a much narrower
area and is soon buried beneath younger beds. Since there is little
difference in the thickness of the beds belonging to this group on the
east and west sides of the arch, it may be readily inferred that the
easterly dips are more steep than the westerly.
The northern end of the arch which forms the peninsula pitches
gently downward, so that the limestones of the Vicksburg group dip







SECOND ANNUAL REPORT-STRUCTURE OF FLORIDA.


below the surface north of Live Oak and Lake City and the forma-
tions comprising the Apalachicola group appear in the valley of the
Suwanee River. The southern end of the arch sinks gently beneath
the younger formations so that the limestones of the Vicksburg group
lie several hundred feet below the surface in Lee County and at Key
West, where they were encountered in drilling wells.
The varying depths to rocks of Oligocene age along the east coast
of Florida are probably due, in part, to local variations in the rate of
dip and to various minor folds. There appears to be little doubt that
any upheaval which produced the broad arch which forms the penin-
sula of Florida would also produce minor arches or folds parallel to
the direction of the main uplift, as well as minor folds transverse to
the main arch. The satisfactory discrimination of these minor folds
calls for a large amount of detailed stratigraphic work based upon a
knowledge of the fossils representing different horizons. It is possible
that the ridges mentioned by Dr. Dall are really minor folds, but he
does not appear to have eliminated the possibility of their being due
to circumdenudation. That there are many minor folds in Florida
cannot be denied. Good examples of such folds are those which DalP1
mentioned on the Caloosahatchee River. These small folds are not
more than ten to twelve feet in height and are usually not more than
one-quarter of a mile wide. They are of more than usual interest be-
cause they involve- marls of Pliocene age and hence are probably of
Pleistocene or even of Recent age.2

Dall, Wm. H., Notes on the geology of Florida. Am. Jour. Sci., 3d series,
vol. 34, 1887, p. 168.
Dall, Wm. H., Tertiary fauna of Florida. Trans. Wag. Free Inst. of Sci.,
vol. 3, pt. 6, 1903, p. 1604.
Dall, Wm. H., Neocene of North America, Bull. U. S. Geol. Survey No. 84,
1892, p. 143.
SFor evidence of minor folds in the Chattahoochee limestone and in the
Alum Bluff formation, see paper on "Fuller's Earth Deposits," by E. H. Sellards
and Herman Gunter (pp. 277-284).






FLORIDA STATE GEOLOGICAL SURVEY.


STRATIGRAPHIC GEOLOGY.

TERTIARY.

OLIGOCENE.

The oldest rocks which have been recognized in Florida belong
to the Oligocene series. They may be separated into two divisions,
called here the Vicksburg group and the Apalachicola group. These
two subdivisions were formerly regarded as Eocene and Miocene,
respectively. One of the earliest attempts to fix the age of the rocks
of Florida was made by Conrad1 in 1846. In his paper Conrad re-
ferred both the "silex beds" and the limestone of the Tampa forma-
tion, together with the prevalent rock of the peninsula, to the upper
division of the Eocene. For many years the rocks here included in
the Vicksburg group continued to be called Eocene by various writers,
including Bailey,2 Tuomey,3 Smith,4 Dall,? and others. The deposits
here called Apalachicola group were first differentiated from the
"Vicksburg" in 1887. when Langdon" examined these formations
along the Apalachicola River and classified them as probably "Mio-
cene." This name was retained for some time, but it was modified
by the use of "Old Miocene" or "Subtropical Miocene" to distinguish
it from the later Miocene. In 1896, Dall7 published a brief statement
of the reason for regarding the so-called Eocene and the so-called Old
Miocene of Florida as Oligocene. This usage has since prevailed in
many, but not in all. of the publications dealing with southern coastal
plain geology.

VICKSBURG GROUP.

After the recognition of the "Old Miocene" there remained a con-
siderable thickness of rock which was still regarded as Eocene and

'Conrad, T. A., Observations on the Geology of a part of East Florida,
with a catalogue of recent shells of the coast. Am. Jour. Sci. 2d ser., Vol. 2,
1846, pp. 36-48.
'Bailey, Prof. J. W., Am. Jour. Sci., 2d ser., vol. x, 1849, p. 282.
STuomey, Prof. M., A notice of the Geology of the Florida Keys. Am. Jour.
Sci., 2nd ser., vol xi, 1850, pp. 390 et seq.
SSmith, E. A., On the geology of Florida, Am. Jour. Sci., 3rd ser., vol xxi,
1881, pp. 292-309.
SDall, Wm. H., Neocene of North America, U. S. Geol. Surv., Bull. 84, 1892,
pp. 101-105.
*Langdon, Danl. W., Jr., Some Florida Miocene, Am. Jour. Sci., 3rd ser.,
vol. xxxviii, 1889, pp. 322-324.
'Dall, Wm. H. Descriptions of Tertiary fossils from the Antillean region,
U. S. Nat. Mus. Proc., vol. xix, No. 1110, 1896, pp. 303-305.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


was known as the "Vicksburg limestone."' This name had been used
to include all the older Tertiary rocks of the peninsula, comprising
both the Vicksburg and the deposits here called Apalachicola group;
but with the increased knowledge of the geology of the State it was
gradually restricted to the older limestones. Subsequent study in-
dicated that this group of older limestones, while presenting but slight
lithologic variation, was divisible upon paleontologic grounds into
two parts, the lower division (here called "Peninsular") being desig-
nated the Vicksburg "limestone" and the upper division being named
the Ocala limestone. Still later, Dall3 proposed the abandonment of
the name Vicksburg as applied to limestones of the peninsula of
Florida, and the substitution of the term "Peninsular" for the lower
division above described. He states:
From the observations on the typical Vicksburgian by Coloney Casey it
seems probable that the Orbitoidal limestone which forms the mass of the Flor-
idian plateau, and which has been, in this work and in the literature generally
called the Vicksburg limestone, may really form a different horizon altogether
from the typical Vicksburgian and be intermediate between the latter and the
nummulitic Ocala limestone. In order to promote clearness and avoid confusion,
it is probably advisable to adopt a distinct name for the Orbitoidal phase or
formation, for which I would suggest the term Peninsular limestone. This is
intended, not as a permanent formation-name, but as a general term for the
fundamental plateau limestone of Florida, in which a close and thorough study
may result in the discrimination of more than one horizon or zone.
The reason for the change suggested by Dall4 is the fact that the
fossils which have long been regarded as characteristic of the Vicks-
burg have been found to occur in other horizons, and hence their
occurrence in the limestones which underlie the nummulitic rock of
the peninsula cannot be regarded as proof of equivalence of that lime-
stone with the limestone at the type locality at Vicksburg, Miss. The
question of the correlation of the Florida formations has been further
complicated by the fact that there are two horizons represented in the
bluff at Vicksburg. To avoid further confusion, however, the
Oligocene rocks in Florida which were originally known as the Vicks-
burg "limestone" are here designated the Vicksburg group. They are
thought to comprise three formations, here called the Ocala lime-
stone, the "Peninsular" limestone and the Marianna limestone.
The "Peninsular" and Ocala limestones have already been recog-
nized by Dall. The name Marianna limestone is here given to the
soft, porous, light-gray to white limes:ones of western Florida, which

'Dall, Wm. H. Neocene of North America, U. S. Geol. Survey, Bull. 84,
1893, pp. 101-104.
SSmith, E. A. On the Geology of Florida, Am. Jour. Sci., 3rd ser., vol. xxi,
1881, pp. 292-309.
SWagner Free Inst. of Sci., vol. iii, pt. 6, p. 1554.
"Loc. Cit.






FLORIDA STATE GEOLOGICAL SURVEY.


are characterized by an abundance of Orbitoides mantelli and other
foraminifera associated with many other fossils, prominent among
which are Pecten poulsoni and P. perplanus. At the type locality,
(Marianna, Jackson County) this limestone is so soft that it can be
cut into blocks with a saw. It contains some beds of chert and many
of the fossils are silicified. Lithologically, the rock at Marianna re-
sembles the Ocala limestone at Ocala and the "Peninsular" limestone;
but it differs from the former in the character of its fauna, especially
in the absence of nummulites, and it is believed that it may represent
a horizon below the "Peninsular" limestone of Dall. The close lith-
ologic resemblance between the Marianna limestone and the "Peninsu-
lar" limestone, however, makes it possible to combine much of the
discussion concerning these two formations.

MARI.NNA AND PENINSULARR" LI.IESTONES.

Stratigraphic Position:-The base of the "Peninsular" limestone
is not exposed in Florida and there is no satisfactory evidence that it
has been reached in drilling wells; hence the character of the sub-
jacent formation is not known. Reference has already been made to
the uncertainty concerning the exact correlation of the "Peninsular"
limestone of Florida. It will thus be seen that no satisfactory con-
clusions can be drawn concerning the relation which the "Peninsular"
limestone bears to the underlying beds. The relation of the Peninsular
limestone to the overlying formations will be discussed in connection
with those formations.
The Marianna limestone is thought to be the stratigraphic equiva-
lent of the upper part of the bluff at Vicksburg, Miss.. and some of
the wells in west Florida enter beds of sand and clay which probably
represent older horizons; but the stratigraphic relation of the forma-
tion to these older beds cannot be determined. In west Florida. where
this formation is recognized, it is unconformably overlain by beds be-
longing to the Apalachicola group or by post-Pliocene formations.
Lithologic Character:- The Marianna and "Peninsular" forma-
tions consist of soft, porous, white or light-gray limestone, sometimes
resembling marl, especially when partially decomposed. Some bands
of darker-colored, dense limestone are reported at various localities
where these formations have been penetrated by drilling, and nodules
and layers of chert are common throughout them, but chert beds are
especially prominent in certain horizons. The chert beds are usually
darker in color than the limestone and range in thickness from a frac-
tion of an inch to twelve or fifteen feet. In some localities as many
as six or seven successive beds of chert have been encountered in a
single well. In general, the heavier layers are more persistent: and it






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


is usually the chert which forms a nearly water-tight cap to the ar-
tesian water beds in these formations. Certain horizons are abund-
antly fossiliferous, containing innumerable specimens of Orbitoides
and shells of mollusks such as Pecten poulsoni, etc. At several local-
ities the rock is so soft that it can be cut into blocks with a saw; and
upon exposure to the weather these blocks harden rapidly, making a
very fair quality of building stone. Beds of sand, sometimes ten feet
or more in thickness, are reported in some of the wells which pene-
trate this formation. In general, these sands appear to be most
numerous in the northwestern part of the State.
Thickness:-The thickness of the "Peninsular" limestone and the
Marianna limestone appears to be exceedingly variable. The thickness
given by Foerste,' from his investigations of the Vicksburgian lime-
stones in southwestern Georgia and the adjacent part of Florida, is
220 feet, and probably this may be regarded as the approximate
measure of the thickness of the Marianna. At Salt Mountain, Ala-
bama, the rocks of the Vicksburg group are reported by Dr. Dall2 to
have a thickness of 140 feet, and on the basis of well borings the same
writer estimates the thickness to be over 350 feet at Gainesville, 212
feet at Lake Worth, and 1,068 feet at St. Augustine. From recent
examinations of well borings by Drs. Vaughan and Bassler, limestone
of Vicksburg age is known to have a thickness of over 225 feet at
Quincy, 250 feet at Alachua, and 325 feet at Bartow. Apparently
there is a marked thickening of these limestones from the exposures
of Georgia and Alabama southward. It is hard to tell just how much
reliance can be placed on well records, because the drill may penetrate
some distance into a formation before characteristic fossils are ob-
tained; and it is possible for fossils to drop from the side of the bore
and thus continue to appear in the drillings far below the base of the
formation to which they belong. Of all the estimates given above the
one at Gainesville is probably the most reliable because the well is
cased to the bottom.
Physiographic Expression:--The "Peninsular" and Marianna
limestones are characterized by a topography produced by solution
with numerous underground streams, natural bridges, sink-holes and
large irregular depressions. The underground streams of these form-
ations attain considerable size as is shown by a number of large
springs which emerge, apparently from definite channels. The most
noted natural bridge of the Marianna limestone is on the Chipola
River near Marianna; but there are many of smaller size, both in

'Foerste, Aug. F., Am. Jour. Sci., 3rd ser., vol xlviii, 1890, p. 46.
'Dall, Wm. H., Neocene of North America, U. S. Geol. Survey, Bull. 84,
1892, p. 103.


* 53






FLORIDA STATE GEOLOGICAL SURVEY.


this formation and in the "Peninsular" limestone. Wherever the lime-
stone rises near the surface, sink-holes characterize the topography,
and the sinks form many lake basins in the central part of the pen-
insula. (See Fig. I, pi. II, p. 58.)
Paleontologic Characters:-Both the "Peninsular" limestone and
the Marianna limestone are characterized by an abundant fauna, the
most prominent fossil being Orbitoides mantelli, associated with
Pecten poulsoni and P. perplanus. DallI says that the fauna of
the "Peninsular" limestone includes about two hundred and twenty-
two species, of which one hundred and two are restricted to it. With
the imperfectly known fauna of the Ocala limestone, it has fifteen
species in common, while nine species continue into the "silex beds"
and limestone of the Tampa formation and two species continue into
the Miocene and on down to the recent fauna.
Structure:-The "Peninsular" and Marianna limestones have been
affected by the various earth movements which have produced the
present structure of the State. The major structural features consist
of broad anticlinals, such as are described under the general discus-
sion of the structural features of the State. The dips are low and are
generally seaward. Local variations in altitude of the surface of these
limestones are so pronounced as to suggest that there has been con-
siderable local warping as well as a general arching. Toward the
southern end of the peninsula the "Peninsular" limestone dips south-
ward beneath the Everglades where it is probably buried under
hundreds of feet of younger sediments. Along the east coast there
are marked variations in depth to this formation: but it probably does
not rise within less than about 200 feet of the surface, and at Jack-
sonville it is not less than about 525 feet from the surface.
At Tampa, on the west coast, the "Peninsular" limestone probably
lies somewhat more than 100 feet below the surface, but farther north
along the coast it may be exposed. Apparently the dip of the Mari-
anna limestone toward the southwest in the long western extension
of the State is very rapid, for at Pensacola this limestone is buried to
a depth of more than 1,100 feet beneath younger sediments.
Local Details:-As early as 1849 limestone of Vicksburg age was
noted in Florida by J. XV. Bailey.2 who obtained some "Orbitulites"
from a chert at Pyles Plantation, about forty miles west of Palatka.
The exact location of the settlement where these specimens were ob-
tained is not known. The same writer mentions the occurrence of
similar rock at several points between Palatka and Tampa, but in no
case does he give the exact localities.

'Wagner Free Inst. Sci. Trans., pp. 1553.
'Bailey, J. W., Amer. Jour. Sci.. second series, 1831, vol. ii, p. S6.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


While collecting statistics for the Tenth Census Dr. Smith' gath-
ered much valuable information relating to the geology of Florida.
The results of these geological investigations were published in 1881.
After summarizing the previous literature Dr. Smith presented evi-
dence to show that limestone of Vicksburgian age underlies nearly the
entire peninsula of Florida. He gave in part its areal outcrop and
noted the occurrence of Orbitoides mantelli and Pecten poulsoni, and
other characteristic fossils in exposures of the limestone here called
Marianna a few miles southeast of Campbellton, at the Big Spring,
east of Marianna, and at other localities which he does not name.
From a limestone collected by him six miles from St. Marks, in
Wakulla County, Heilprin identified Orbitoides mantelli and pro-
nounced the rock to be "Vicksburg," but the rock at St. Marks is now
known to belong to the Apalachicola group instead of the Vicksburg.
Dr. Smith examined a marl which occurs at various points along the
Gulf coast and decided that it also was of Vicksburg age. He states
that this marl forms the basis of the "Gulf Hammock" land in the
coastal counties from Wakulla County nearly to Tampa Bay in Hills-
boro County. In describing the areal extent of the "Vicksburg,"
Smith included in it large areas of rock which is now known to belong
to the upper Oligocene or Apalachicola group: for example, the lime-
stone extending along the Suwanee River for many miles, and the
limestone at Tampa were, on the observations of others, wrongly in-
cluded in the Vicksburg. He called attention to the fact that the
Vicksburgian limestone is the prevailing rock in the vicinity of Gaines-
ville and that it is often composed largely of Orbitoides mantelli.
Other localities included in the Vicksburg were Payne's Prairie and
Ocala.
In addition to the localities mentioned above, Smith reports lime-
stone of Vicksburg age at Live Oak and Lake City in the northern
part of the peninsula. At these localities, as in many other parts of
the peninsula, the formation is overlain by a few feet of younger rock.
Dr. Dall gives the following summary of localities where the "Vicks-
burg" limestone has been observed:
It is impracticable with the data yet printed to determine exactly at how
many of Smith's localities the country rock belongs to the Orbitoides horizon.
Some of them, doubtless, will eventually be shown to be of later age, as will be
indicated later in this summary. Only those where no doubt seems to exist will
be specified here. In Alachua County it is widespread, having been observed
by Smith and Dall at Gainesville and westward to and about Archer, though
in many places overlain by solutionary residium, remnants or even beds of later
age but moderate thickness. It had been identified at Silver Spring, 6 miles east

'Am. Jour. Sci. (3) xxi, 292-309, 1881.
2 Op. cit. pp. 102-103.






FLORIDA STATE GEOLOGICAL SURVEY.


from Ocala, by Le Conte, as early as 1861,' and subsequently the observation has
been confirmed by Smith. Specimens of this rock have been collected by Will-
cox at Martin station, Marion County, about 8 miles north of Ocala, where the
rock is very cherty; and at Jarves' Spring, on the southern border of Pasco
County; at Fort Foster, on the North fork of the Hillsboro River, where, as in
many other places, relics of the old Miocene beds overlie it. Several"of the
localities referred to by Heilprin must remain for the present on the doubtful
list, but among them should hardly be counted the islet at the mouth of the
Homosassa River, from which Mr. Willcox obtained the Pygorhynchus
(Raveselia) gouldii Bouve, a small echinoderm originally described from the
buhrstone (ante-Claibornian) of Georgia.
It will be seen from this quotation that later investigations indicate
that the limestone at some of the localities mentioned by Smith is not
all of Vicksburgian age. However, this should not be regarded as
detracting from. the value of the earlier work, for with. the increase
of knowledge it is inevitable that formation lines should be shifted
and that new formations should be discriminated.
Miss Maury's2 summary of the Vicksburgian indicates that it
forms a large part of the country rock in north central Florida, and
she cites many of the localities mentioned by Dall and Bailey. She
mentions especially the exposures seen in the vicinity of Gainesville,
which are surrounded by rocks belonging to the subdivision here
called Apalachicola group. Attention is also called to the occurrence
of gypsum, which is regarded as the result of the action of sulphur
on calcium carbonate, and the occurrence of phosphate rock resulting
from an analogous chemical action,
During the progress of recent field work the occurrence of the
Marianna limestone was noted at Natural Bridge in north central
Walton County, but there is no indication that it reaches the surface
west of this county; indeed, from well records and exposures of other
formations, there is every reason to believe that in Escambia and Santa
Rosa Counties, this formation lies some hundreds of feet below the
surface of the upland.
East of Marianna the formation is exposed at several localities
where it presents considerable variation in its lithologic characteristics.
At some of these localities it is a soft, porous, white limestone, while
in other places it is a tough, dense, gray limestone. However, some
of this difference in texture may be accounted for by the fact that
the rock hardens upon exposure to the air, and it is perhaps a sig-
nificant fact that the hard, gray limestone usually occurs at natural ex-
posures while the soft, porous rock is seen in the quarries.

'Am. Jour. Sci., 2nd ser., 1861. vol. xxi, pp. 1-12.
Maury, Carlotta Joaquina. The Oligocene of western Europe and southern
United States. Bull. Amer. Paleont., vol. iii, No. 15, 1902, pp. 45-46.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


Near the east edge of the town of Marianna there is a small ex-
posure which affords the following section:
SECTION No. 1.
Red, sandy clay, with some beds of sand and gravel, Lafayette......... 25 ft.
Marianna limestone:
White, marly clay ..................................... ....... 5 ft.
Hard, earthy, gray limestone .................................... 2 ft.
Blue marl with many Pectens .................................... 8 ft.
Hard gray limestone ............ ........................... 4 ft.
Approximately twenty feet below this is section No. 2.
SECTION No. 2.
Hard, gray limestone, very fossiliferous, Orbitoides mantelli, Pecten
poulsoni, etc. ............... ............... ..... ....... 5 ft.
Dark gray chert .................. ........ .. ............... 4 in.
Soft, porous, white limestone, with a few Orbitoides and other fossils... 30 ft.
The white limestone of this section is exposed in a quarry where
it is obtained by sawing. It is used locally for building purposes,
especially in the construction of chimneys; upon exposure to the
weather the rock hardens until it resembles the hard member at the
top of the section.
A well drilled at Marianna penetrated limestone, marl and clay
to the depth of 265 feet, where a bed of quicksand was encountered.
An incomplete log of this well is given below :
Sand and sandy loam, Pleistocene ................................ 1 ft.
Red and yellow sandy clay and sand, Lafayette....................... 20 ft.
Alternating beds of hard limestone and marl........................ 45 ft.
(This doubtless includes section No. 1 at the east end of the town.)
Hard rock (chert) followed by alternating beds of marl and limestone
with some chert, Marianna (?)................................. 200 ft.
The log of this well does not afford any means of judging at what
depth the base of the Marianna limestone was reached, but it is pos-
sible that an underlying formation was penetrated some distance above
the quicksand.
At a locality two and a half miles southeast of Chipley, the Mari-
anna limestone outcrops in the edge of a sink; and about six miles
southwest of Chipley and one mile north of Duncan it is exposed in
some small quarries where it had been obtained for building purposes.
At one of these quarries belonging to Mr. F. G. Owens, the rock has
also been burned for lime, which was reported to be of good quality.
This quarry shows about twenty feet of porous, white limestone, re-
sembling the rock in section No. 2 at Marianna. Near the surface it
is very hard and durable, but at greater depth it becomes much softer.
Fossils occur throughout the entire section, but are especially
numerous in the upper five feet, where the rock appears to be largely





FLORIDA STATE GEOLOGICAL SURVEY.


composed of Orbitoides mantelli. The rock, where it is quarried at
this locality, appears to form a well defined ridge covered by a few
feet of white Pleistocene sand and sandy loam, but its presence is
indicated at various points by numerous boulders containing char-
acteristic organic remains.
A few miles northeast of Duncan at Falling Water, a large sink
exposes several feet of light gray limestone, probably belonging to
the same formation. At this locality there appears to be a well de-
fined system of underground drainage, which is indicated at the sur-
face by numerous sink-holes. The best exposure is seen where a
small stream plunges into one of these sink-holes. The stream is
reported to have a fall of over seventy feet. The rock here forms a
nearly perpendicular cliff and hence the section is not easily accessible.
At Natural Bridge near the north line of Walton County, a light-
gray to yellowish-gray marl forms the arch which spans a small
stream. The width of the channel is probably twenty feet and the
length of the bridge about one-fifth of a mile. The height of the
exposure was estimated by Vaughan' to be about thirty-five to forty
feet above the level of the water in the creek. When fresh, this rock
is soft and crumbles readily in the fingers, but when exposed to the
weather it hardens rapidly and assumes the yellowish color mentioned
above. It is quarried by sawing and is locally known as chimney rock,
because it is used in the construction of chimneys. A considerable
percentage of clay, which occurs in fine particles distributed through
the rock, indicates that the material is a marl rather than a limestone.
Pecten poulsoni is the most abundant fossil. From the lithologic
character of the rock, together with the occurrence of numerous speci-
mens of the species mentioned above, the rock is considered to belong
to the Marianna limestone.
A quarter of a mile south of the Bridge near a turpentine still a
similar marl is exposed in the bed of a small stream. The outcrop at
this locality has a thickness of about twenty feet and it differs lith-
ologically from the marl of the Bridge in being slightly more compact
and of a distinctly grayish or bluish color. However, these differences
are probably due to the fact that this exposure has not suffered so
much weathering as the one at the Natural Bridge, and the sub-
stantial equivalence of the rock at the two localities can hardly be
questioned. Numerous concretions of nearly pure carbonate of lime
are scattered throughout this marl, but they do not appear to have
any relation to the occurrence of the fossils.
About seven miles southwest of Marianna and nearly one mile
from Kynesville, a number of fragments of limestone were obtained

'Vaughan, T. Wayland, unpublished notes.










SECOND ANNUAL REPORT. PL. II.


FIG. 1.-SINK HOLE CONTAINING POND, TEN MILES SOUTHWEST OF
VERNON, WASHINGTON COUNTY, FLORIDA. TYPE OF TOPOG-
GRAPHY OF THE VICKSBURG GROUP.


[ii ,

FIG. 2.-"FALLING WATER," FIVE MILES SOUTH OF CHIPLEY, FLA. THE
SMALL STREAM FALLS INTO A SINK ABOUT SEVENTY FEET DEEP.

Digitized by Google


FLORIDA GEOLOGICAL SURVEY.







SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


from a field where they were said to have been turned up by the plow.
They represent a very cherty phase of the Marianna, and are probably
the residual products of weathering. They consist of boulders up to
two or three feet in diameter containing innumerable specimens of
Orbitoides mantelli and Pecten poulsoni.
At the phosphate mines in the vicinity of Croom, a number of
specimens of Orbitoides mantelli were collected and the rock here
has the lithologic characteristics of the "Peninsular" limestone. The
collection was made from boulders dredged from a mine, and hence
may not be sufficiently characteristic to decide whether this is "Pen-
insular" or Ocala limestone. The presence also of a number of speci-
mens of Cassidulus suggests that limestone belonging to the Apalachi-
cola group is also represented. In the absence of characteristic num-
mulites in the collections, it appears not unlikely that the limestones
of the Apalachicola group may here rest upon the "Peninsular" lime-
stone. However, this conclusion is made subject to revision in case
future collections from this locality should reveal the presence of
fossils belonging to the Ocala limestone.
The "Peninsular" limestone is known to occur throughout the
central part of the peninsula, where it may be observed in numerous
natural and artificial exposures. It has been encountered in many of
the hard rock phosphate mines from Croom northward nearly to the
north line of the State. It is also known to underlie a large part of
the central lake basin of the peninsula. This limestone is encountered
in wells along the east coast from Fernandina southward beyond Palm
Beach, and along the west coast south of Tampa.

OCALA LIMESTONE (NUMMULITIC ROCK.)

The Ocala limestone was formerly regarded as part of the "Or-
bitoides" limestone, but in 1882 nummulites derived from waste prod-
ucts of the Ocala limestone were described by Heilprin. The speci-
mens were obtained by Willcox' on the Chassahowitcka River, and
their association with fresh-water forms of recent shells was rightly
interpreted to mean that the nummulites had been transported from
some other locality and re-deposited with the younger shells. In
1884, Willcox2 announced the occurrence of the nummulitic rock in
place some distance above the original locality on the Chassahowitzka
River and Heilprin, in commenting upon the announcement, stated
that the beds belonged to the Oligocene.

'Heilprin, Angelo. On the occurrence of nummulitic deposits in Florida,
and the association of nummulites with a fresh water fauna. Acad. of Nat. Sci.,
Phila., Proc., 1882, pp. 189-193.
SScience, N. S., vol. iii, 1884, p. 607. ..






FLORIDA STATE GEOLOGICAL SURVEY.


In subsequent publications by the same author this rock was called
the "Nummulitic" limestone, but, in 1892, Dall' proposed the name
Ocala limestone.
Stratigraphic Position:-The Ocala limestone lies stratigraphically
between the "Peninsular" and the beds here designated Apalachicola
group. Lithologically, it bears a strong resemblance to the underly-
ing "Peninsular" limestone, with which it also has a close faunal re-
lation. These facts have led to the conclusion that the two formations
are conformable, and it has also been suspected that the Ocala lime-
stone represented a local phase of the "Peninsular." While the two
formations are probably conformable, the extensive distribution of the
nummulites of the Ocala limestone shows that it represents a wide-
spread change in conditions and is not to be classed as a mere local
phase of the underlying beds.
The Ocala limestone, as already noted by Johnson,2 is sometimes
wanting, so that the overlying formations rest directly upon the
"Peninsular." This relation was noted at several localities which
will be mentioned in discussing the younger formations. At present it
is sufficient to note its absence and to suggest that since the Ocala
limestone does not appear to be a local phase of the "Peninsular,"
there is probably a stratigraphic break between the rocks belonging
to the Vicksburg and Apalachicola groups in the central part of the
peninsula.
Lithologic Character: The Ocala limestone consists of a soft,
porous, light-gray to white limestone which bears a strong lithologic
resemblance to the underlying "Peninsular" limestone, but is dis-
tinguished from it by the included fossils. When slightly weathered,
the rock becomes light yellow, and owing to its granular appearance
is often regarded as sandstone. The removal of the calcareous ma-
terial by the leaching action of underground water leaves a pale yellow,
more or less incoherent sand, containing a small percentage of calcium
carbonate. 'hen fresh, the Ocala limestone is so soft that it is easily
broken, but exposed surfaces often become hardened by the deposition
of calcium carLonate from the waters which emerge along the outcrop.
For this reason the rock frequently appears to be hard and firm. Its
porosity and ready solubility permit the formation of numerous under-
ground channels which are sometimes seen at the outcrop and are
inferred from the presence of numerous sink-holes. The rock con-
tains an abundance of organic remains which are commonly preserved
as casts. Nodules and large masses of chert are also common and in
some localities a large part of the rock has been silicified.
'Dall, Wm. H. Neocene of North America. U. S. Geol. Surv., Bull. 84, 1892,
pp. 103-104.
"Johnson, Lawrence C. Op. cit.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


Thickness:-No definite determination of the maximum thickness
of the Ocala limestone has been made, and as yet no exposures have
been observed which show the contact with the underlying "Peninsu-
lar" limestone. All the information now available indicates that the
thickness may be variable, and that the variation is in considerable
measure due to subsequent erosion rather than inequalities of depo-
sition. In the Transactions of the Wagner Free Institute of Science,
Dr. Dall states that at the type locality the Ocala limestone has been
quarried to a depth of twenty feet without reaching its contact with
the underlying "Peninsular" limestone. The greatest thickness noted
during the recent field investigation was in a sink-hole near Ocala
where the formation is exposed to a depth of about forty feet without
reaching its base. This locality is described in a subsequent part of
the discussion.
Physiographic Expression:-As in the case of the "Peninsular"
limestone, the Ocala limestone is soft and porous, and hence gives
rise to a topography which is characterized by underground channels,
sink-holes, sinking streams, natural bridges, and large springs. The
limestone has an important influence in the formation of many of
the lake basins, and it forms the natural bridge of the Santa Fe River
near High Springs. Large springs from the Ocala limestone are
numerous in the central part of the peninsula.
Paleontologic Characters:-The Ocala limestone, like the under-
lying "Peninsular," is characterized by a great number of foraminif-
era, but it differs from the latter in the presence of nummulites. A
few mollusks are said to be restricted to this formation, but as yet
the fauna is very imperfectly known, and future study may add to the
number of fossils which are peculiar to it.
Structure:-The Ocala limestone shows the same structural feat-
ures as the underlying "Peninsular," and there is little reason to doubt
that both have been subjected to the same movements since their
deposition.
Local Details:-One of the earliest statements relating to the type
locality of the Ocala limestone was made by Prof. LeConte in his
description of the Silver Spring.2 He says (p. 11) :
As in some measure related to the peculiar system of subterranean drainage
above indicated, it may not be deemed inappropriate to conclude this communica-
tion with a few general remarks in relation to the physical causes which have
produced the several qualities of surface soil which are found in the neighbor-
hood of Ocala and the Silver Spring. The whole of this portion of the Penin-

'Dall, Wm. H., Trans. Wagner Free Inst. Sci., vol. iii, pt. 6, 1903, p. 1556.
SLe Conte, Prof. John. On the optical phenomena presented by the "Silver
Spring" in Marion County, Florida. Am. Jour. Sci., 2nd series, vol. xxxi, 1861.
pp. 1-12.






FLORIDA STATE GEOLOGICAL SURVEY.


sular appears to have been originally composed of a mixture of sand and shell-
limestone; probably of the Eocene period. The lime-rock comes to the surface
almost everywhere; in some cases it is composed of nearly pure carbonate of
lime; in others silicification, to a greater or less extent, has taken place by the
displacement of the lime by silex. But in all cases where its structure can be
made out, it consists of a mass of conglomerated shells.

A later paper by Conradi mentions some of the fossils found in
the Ocala limestone, and correlates it with the Shark River Eocene of
New Jersey. However, neither Prof. Le Conte nor Conrad made any
special study of the Ocala limestone, and it remained for later work-
ers to recognize its distinctive characteristics.
The Ocala limestone was for a long time regarded as a part of
the Vicksburg "limestone," as it was then known; but it was later
separated from the Vicksburg. It was in 1882 that Mr. Joseph Will-
cox discovered a rock from the vicinity of Chassahowitzka River which
he submitted to Heilprin2 for identification. Heilprin recognized some
of the fossils as nummulites, and to a new species belonging to this
genus he gave the name N. willcoxii. In 1886 Prof. Heilprin3 added
another to the published list of localities where the nummulitic fauna
is known to occur. This new determination was based upon the pres-
ence of Vizummulites floridanus which was obtained near Arredondo
about six miles southwest of Gainesville. The specimens were col-
lected by Prof. G. A. Wetherby and Mr. Joseph Willcox.
In his paper on the Neocene of North America, Dr. Dall4 mentions
Prof. Heilprin's discovery of nummulitic rock in Florida and suggests
the name Ocala limestone from the locality where it is best exposed.
He states (p. 103) :

Among the rocks which until recently were not discriminated from the
Orbitoides limestone, and which' appear in central Florida directly and con-
formably to overlie the latter, though no one has described their contact, is a
yellowish friable rock containing many foraminifera, conspicuous among which
are two species of nummulites, N. willcoxii and N. floridana Hp. This rock was
first brought to notice by Mr. Joseph Willcox, and to Prof. Heilprin we owe a
description of it which discriminates between it and the Vicksburg or Orbitoides
rock. The rock was early recognized as Eocene, though not discriminated from
the earlier beds. It is best displayed at Ocala, Florida, where it forms the
country rock, and has been quarried to a depth of 20 feet without coming to
the bottom of the beds.

'Conrad, T. A. Observations on American fossils with descriptions of two
new species. Proc. Acad. of Natural Sciences, Philadelphia, 1865, p. 184.
'Heilprin, Angelo. Proc. Acad. of Nat. Sci., Philadelphia, 1882. pp. 189-
193. Abstract of same, Am. Jour. Sci., 3rd ser., vol. xxiv, 1882, p. 294.
SHeilprin, Angelo. Notes on the Tertiary geology and paleontology of the
southern United States. Am. Jour. Sci., 3rd series, vol. xxix, 1885, p. 69.
'Dall. Win. H. Neocene of North America, U. S. Geol. Survey. Bull. 84,
1892, pp. 103-104.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


After summarizing the results of previous investigations, Dall1
mentions the following new localities where the Ocala limestone is
exposed:
Since then Mr. Willcox has obtained the rock in place 15 miles northeast
of the original locality, from the shore of Wacassassa Bay, near Cedar Key,
and also from the banks of the Wacassassa River, Levy County; from a "sink-
hole" at Pemberton's Ferry' on the Withlacoochee River; about 10 miles east-
ward from Brooksville and also at Bayport, Hernando County, and at various
places about Ocala. Prof. Wetherby has also sent specimens from a well 5
miles southwest of Gainesville, Alachua County, and Mr. L. C. Johnson reports
it from an old Confederate iron furnace, 3 miles north of Levyville, Levy
County, where it is only 20 feet thick and is covered with a bed of bog-iron ore
formerly worked. Pemberton's Ferry is the most southern point at which it
has been recognized at the surface, but at Bartow, Polk County, it occurs
covered by about 6 feet of later strata.
From the character of its included organic remains the exposure
at Martin Station3 is regarded as equivalent to the Ocala limestone,
At this locality, the rock is more or less silicified and hence has been
found useful for railroad ballast, road metal and other purposes where
durable material is needed.
To the rock at the old Confederate iron works in Levy County,
Mr. Johnson4 gave the name "Levyville formation," and states that it
consists of about twenty feet of soft, porous building stone. He be-
lieved that it has been partially removed by erosion in the western part
of the peninsula where it is much thinner than farther east. He also
expressed doubt as to its ever having been deposited over the entire
surface of the underlying Vicksburg.
Several other localities were mentioned where this formation was
recognized, among them being Payne's Prairie. At a quarry on the
Newnanville road near the Santa Fe River, Johnson reports that the
Neocene formations rest directly upon the limestone of Vicksburg age
the nummulitic rock (Ocala) being absent. Johnson's Levyville form-
ation has usually been regarded as the substantial equivalent of the
Ocala limestone; but it is not possible at the present time to verify
the determination of the nummulites, and the rocks at Levyville may
really. belong to some other formation.
In 1902 Miss Maury5 summarized the known distribution of the
Ocala limestone, but did not give any new information relating to it.

'Ibid. p. 104.
*Now called Croom.
*Dall, Wm. H., Trans. Wagner Free Inst. Sci., vol. iii, pt. 6, 1903, pp.
1156-1157.
'Johnson, Lawrence C. Op. cit.
Maury, Carlotte Joaquina. A comparison of the Oligocene of western
Europe and southern United States. Bull. of Am. Paleon., vol. iii, No. 15,
1902, p. 47.





FLORIDA STATE GEOLOGICAL SURVEY.


She appears to have obtained her facts relating to the formation from
some of the publications already mentioned.
The Ocala limestone is extensively exposed at the type locality
where it has been quarried for the construction of roads and the manu-
facture of lime. Exposures are occasionally seen in the walls of sinks
and its presence ma" also be inferred by the appearance of numerous
boulders containing nummulites. These scattered fragments are fre-
quently found resting upon the surface sands and are usually rather
firmly cemented, probably by an accumulation of silica and iron. A
thin deposit of sand is commonly found resting upon the uneven sur-
face of the limestone. In such cases the sand appears to be largely the
result of disintegration of the country rock, and it is therefore residual.
While this statement concerning the origin of such sands may seem
improbable, it is explained by the fact that the soil formed from the
limestone is the insoluble material left after solution has removed the
calcium carbonate. Consequently the residual sands constitute the
impurities of the original rock and may in some cases have formed
only a small percentage of the whole. Since the publication of Dall's
report, quarrying at Ocala has been carried to a somewhat greater
depth. The quarry of the Florida Lime Company, situated near the
southwest corner of the city, now shows:
Sandy loam with more or less organic matter Pleistocene........... 1 ft.
Sand, pale yellow, residual ....................................... 1-4 ft.
Light gray to white nummulitic limestone (Ocala) ................ 25-30 ft.
In this quarry the fossils occur throughout the greater portion of
the limestone, but are especially numerous near the top where the
removal of the calcium carbonate has loosened the casts of the organic
remains. In addition, the quarry presents certain other points of
interest in the arrangement of the cherty portions of the rock. Chert
nodules occur in various parts of the section and in places two sets
of vertical silicified bands were noted. These cherty bands are at
approximately right angles to each other and probably represent planes
of silicification along vertical joints.
A good section of this limestone is exposed in another quarry
situated on the north side of the road to Silver Spring about a half
mile east of the town. At this locality, the rock, which is consider-
ably decomposed, has been quarried to a depth of forty feet and con-
tains an abundance of nummulites.
About twenty feet of Ocala limestone is exposed in a third quarry
situated a quarter mile north of Ocala, and about fifteen feet of the
same rock was seen in a quarry two and a half miles southwest of the
city. One of the most important sections may be seen in a sink-hole
about three miles southwest of Ocala. This sink-hole is approximately
forty feet deep and affords entrance to a small cavern which may be











SECOND ANNUAL REPORT. PL. III.


:ic. 1.-QUARRY OF OCALA LIME CO. (OLD PHIIILLIPS QUARRY)
ONE MILE SOUTHEAST OF OCALA, FLA., SHOWING DE-
COMPOSED ZONES AND SOLUTION CHANNELS IN OCALA
LIMESTONE.


Fic. 2.-OCALA LIMESTONE LEDGES IN PIT OF FORT WHITE
HARD ROCK COMPANY, FORT WHITE, FLA.


FLORIDA GEOLOGICAL SURVEY.







SECOND ANNUAL R1FPORT-STRATICRAPHIC GEOLOCfY.


penetrated a short distance. Mr. Clapp reports that nummulites occur
down to the base of this exposure, but are not so numerous as at some
of the other localities. Lithologically this rock is essentially the same
as that exposed at the quarry of the Ocala Limestone Company, and
the section shows the maximum observed thickness of the formation.
At the old "Phillips" quarry, one mile southeast of Ocala, there is
a section which shows about twenty-five feet of soft, porous, light-
gray limestone which contains an abundance of chert throughout the
entire section. Since this rock contains many nummulites, its identi-
fication as the Ocala limestone can scarely be questioned. Solution
cavities are common and along certain vertical crevices the rock has
been removed, forming passages two or three feet in width. These
have been filled by the settling of the overlying sandy clay.
On the Anclote River, about one mile from Tarpon Springs, there
is an exposure showing from two to three feet of nummulitic limestone
which extends some distance up the stream. The rock here lies near
the surface over a considerable area and boulders containing num-
mulites are common. A similar exposure of Ocala limestone was
noted near Port Richey on the Pithlachascotee River where the rock
is said to outcrop over a considerable area. At the mine of the Fort
White Hard Rock Company, one-half mile southwest of Fort White,
the Ocala limestone is well exposed. In the north pit belonging to
this company, the following section was observed:

Light-gray sandy loam, Pleistocene .............................. 4-8 ft.
Fine, even-grained, yellow sand, residual .......................... 20 ft.
Limestone and phosphate rock, Ocala limestone..................... 25-30 ft.

In this pit the Ocala limestone occurs in irregular ledges separat-
ing the.phosphate rock which appears to be in part the result of re-
placement of the country rock. The. limestone ledges commonly form
two discontinuous series at approximately right angles to each other,
the intervening space being occupied by the irregular bodies of phos-
phate rock. In general, the limestone bands thicken toward the base
of the pit, and the phosphate deposits become smaller. Both the lime-
stone and phosphate are more or less cherty, but the silicification ap-
pears to be in the form of nodules and small boulders rather than ex-
tensive replacement. Fossils are very abundant in the limestone,
prominent among them being the characteristic Nummulites of this
formation. At the mine of the Cummer Lumber Company, four miles
west of High Springs, there is a similar exposure of the Ocala lime-
stone. At this locality the rock lies much nearer the surface, the total
thickness of overlying sand being seldom greater than ten feet. There
is the same characteristic arrangement of the limestone and phosphate
rock as at Fort White.
3g






FLORIDA STATE GEOLOGICAL SURVEY.


Similar relations between the Ocala limestone and the phosphate
were observed at the mine of the Union Phosphate Company, seven
miles east of Newberry. The Alachua sink was visited by Mr. Clapp,
who reported an exposure of about ten feet of soft, white limestone
containing many flint nodules. From the collections made at this
locality it is evident that the Ocala limestone forms part of the walls
of the.sink and it also appears probable that the overlying Hawthorne
formation is present. On the island across the Indian River from Mel-
bourne, Dr. Sellards reports the occurrence of the Ocala limestone
at a depth of 221 feet. This determination was made from fragments
of the rock obtained by Mr. Oliver Gibbs in drilling a well. The rock
was found to contain nummulites, and although the specimens were
not specifically determined, the occurrence of the genus appears to
warrant its correlation with the Ocala limestone. This is a point of
special interest because it shows the Ocala limestone to be nearer the
surface in that part of the State than would naturally have been in-
ferred from previous publications.
The Ocala limestone is known to be well exposed at various points
in the region where rock phosphate is being mined. Nummulites have
been collected from various mines in the vicinity of Hernando, Citrus
County. In a pit Sec. 10, T. 18, S. R. 19 E, the following section
was observed:
Yellow sand, with phosphatic gravel and brown and yellow clays;
also phosphatic white and gray sand, sometimes greenish........ 2-3 ft.
Phosphatic bluish-gray clays, some hard sandstone with boulders of
hard rock phosphate containing nummulites.
The entire section probably represents altered and weathered phos-
phatic Ocala limestone.
Nummulites were also obtained by Eldridge from a stone.quarry
on the Burns place one and a half miles southwest of Owensboro,
Citrus County, and on Mr. Clement's mine No. 8, on the east side
of Blue Springs, T. 16 S., R 19 E.
Miliolite Limestone:-In 1887 Heilprin' noted at Wheeler's, on
the Homosassa River, the occurrence of a porous and cavernous lime-
stone, which he called Miliolite limestone because of the presence of
many foraminifera belonging to the Miliolidae. Dail2 reports similar
rock six miles southwest of Lake City, and thinks the "Miliolite" lime-
stone belongs with the other foraminiferal limestones; but he does
not express an opinion as to whether it belongs with the "Peninsular"
or Ocala limestone. The "Miliolite" limestone is here placed with

'Heilprin, Angelo. Explorations on the West Coast of Florida, Wag. Free
Inst. Sci., Trans., vol. i, 1887, p. 57.
SDall, Wm. H., Neocene of North America, U. S. Geol. Survey, Bull. 84,
1892, pp. 104-105.







SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


the Vicksburg group, and is tentatively referred to the Ocala lime-
stone, to'which it probably belongs.

APALACHICOLA GROUP.

Prior to 1887 the rocks belonging to the group here designated
Apalachicola group from the exposures along Apalachicola River, in
western Florida, were included with the Eocene and were regarded as
part of the "Vicksburg" ("Orbitoides") limestone. In that year
Langdon' observed a group of beds occurring on the Apalachicola
River which he referred tentatively to the lower Miocene, designating
them the Chattahoochee group. With the Miocene beds Dall,2 in 1892,
included not only the Chattahoochee group of Langdon, but the Haw-
thorne formation, the so-called "Waldo formation," the "Tampa lime-
stone," the "Tampa silex bed," the Chipola marl, the Alum Bluff for-
mation and certain sands, gravels and clays, which he did not spe-
cifically name
The use of the name Miocene to designate the group here called
Apalachicola continued for a number of years, the Oligocene beds
being often called "Old Miocene" or "Sub-tropical Miocene," to dis-
tinguish them from the "new" or "cold-water" Miocene. In 1896 DallP
discussed the faunal reasons for regarding the "Old Miocene" as
Oligocene, and in his publications since that date he has restricted the
term Miocene to later beds (here called Jacksonville limestone and
Choctawhatchee marl). However, the Chattahoochee formation is
still included in the Miocene by both Smith4 and McCallie.5
The Apalachicola group was formerly designated the Chipolan
stage6 and the Chipola group,7 but these names are abandoned because
the name Chipola has been used to designate a marl belonging to the
group.
The Apalachicola group includes a number of beds differing widely
in lithological character; though they are recognized by their fossils

*Langdon, Danl. W., Jr., Some Florida Miocene; Amer. Jour. Sci., 3rd
ser., vol. xxxviii, 1889, pp. 322-324.
*Dall, Wm. H., Neocene of North America, U. S. Geol. Surv. Bull. 84,
1892, pp. 105-123.
Dall, Wm. H., Descriptions of Tertiary Fossils From the Antillean Region,
U. S. Nat. Mus. Proc., vol. xix, No. 1110, 1896, pp. 303-305.
'Smith, E. A., The Underground Water Resources of Alabama; Geol.
Survey of Alabama, 1907, p. 81.
SMcCallie, S. W., The Preliminary Report on the Underground Waters
of Georgia, Geol. Surv., of Georgia, 1908, pp. 31 and 32.
*Dall, Wm. H., North American Tertiary Horizon, U. S. Geol. Surv., 18th
Ann. Report, 1896-1897, p. 334.
Foerste, A. F., Studies on the Chipola Miocene of Bainbridge, C and
of Alum Bluff, Fla., Am. Jour. Sci., 3rd ser., vol. xlvi, 1893, p. 244.






FLORIDA STATE GEOLOGICAL SURVEY.


as integral parts of a single group. While limestones and marls pre-
dominate, the group also includes beds of nearly pure sand and clay.
The entire period of deposition appears to have been characterized by
the accumulation of more or less terrigenous materials, and hence the
limestones are usually rendered somewhat impure by an admixture of
clay and sand. At certain times the conditions appear to have been
especially favorable for the development of organic life and some
horizons, such as the Chipola marl member of the Alum Bluff forma-
tion, and the "silex bed" of the Tampa formation contain very large
faunas.
Owing to the lithologic variations and widely separated exposures,
the exact correlation of the formations of this group is dependent
upon their organic remains. While the paleontological studies, espe-
cially those made by Dall, have shed much light upon the stratigra-
phic relations of the different beds, there are still many points which
cannot as yet be fully decided. For this reason it seems best to re-
tain the names of various beds and to indicate as far as possible their
known relationships. The Apalachicola group is separated into four
formations-the Chattahoochee, the Hawthorne, the Tampa and the
Alum Bluff. There is, however, some reason for believing that the
first three are, in part at least, synchronous, though exact equivalence
is difficult to determine where outcrops are widely scattered and faunal
variations are slight. The Alum Bluff formation is clearly younger
than the Chattahoochee formation, upon which it rests.
The name Chattahoochee group was first applied by Langdon1 to
the beds occurring at a series of exposures along the Chattahoochee
and Apalachicola Rivers. The localities examined by Langdon extend
from the final disappearance of the Vicksburg, nine miles by water
above River Junction (Chattahoochee) to the point where the Oligo-
cene exposures give place to the overlying sands and marls of younger
formations. The exposures examined are at Alum Bluff, Rock Bluff,
Ocheesee and River Junction.
In 1893 the section along the Apalachicola River was examined by
Foerste2 who recognized the presence of three dissimilar groups to
which he gave the names Chattahoochee, Chipola and Chesapeake.
His paper gives considerable attention to the character of the materials
comprising his Chipola and Chesapeake groups, with a view to corre-
lating them with the non-marine deposits grouped under the names of

SLangdon, Daniel W., Jr., Some Florida Miocene. Amer. Jour. Sci., 3rd
ser., vol. xxxviii, 1889, p. 322.
'Foerste, A. F. Studies on the Chipola Miocene of Bainbridge, Ga., and
Alum Bluff, Fla., with an attempt at correlation of certain Grand Gulf Group
beds with marine Miocene beds eastward. Amer. Jour. Sci., 3rd ser., vol. xlvi,
1893, pp. 244-254. .. .







SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


"Grand Gulf and Lafayette formation." The major portion of the
discussion, however, deals with the conditions of sedimentation during
the deposition of the rocks belonging to the various groups.
In 1892 Dall1 divided the formations here called Apalachicola group
into two groups, retaining the name Chattahoochee group for the
limestones and marls which are extensively developed in the north-
central part of the peninsula, and employing the name Tampa group
to include the beds which he called Chipola marl, Alum Bluff sands,
Sopchoppy limestone, Tampa limestone and Tampa silex bed. In his
later paper on the Tertiary faunas of Florida, Dall places the "silex
bed" at Tampa in his Chattahoochee group. The discovery of the
characteristic species of the genus Orthaulax in the basal portion of
the Chattahoochee formation led to this change in the correlation.
HAWTHORNE FORMATION.

In 1892 Dall2 described, under the name of Hawthorne beds, some
limestones, sands and clays, extensively exposed in the interior of
Florida, which had been observed by L. C. Johnson. These beds are
here designated the Hawthorne formation. At the time of the pub-
lication of Dall's report the Hawthorne formation was being quarried
and had aroused considerable interest because of the presence of phos-
phoric acid in the rock. The formation consists of clays, sands and
phosphatic limestones and lies stratigraphically between the lime-
stones of the Vicksburg group and the Alum Bluff formation.
SStratigraphic Position:-The stratigraphic relation of the Haw-
thorne formation to the underlying rocks of the Vicksburg group has
been observed at several localities in the interior of the peninsula.
From what is said concerning the geologic history, it is apparent that
the deposition of the Vicksburg group was followed by a widespread
emergence of the land which permitted extensive erosion and the
formation of hills and valleys. There is no doubt that this emergence
and consequent erosion affected the central part of the peninsula,
where the Hawthorne formation is well exposed, for this formation
rests uncomfortably upon either the Ocala or the "Peninsular" lime-
stone at many localities. This relation is emphasized by the lithologic
character of the beds, for there is an abrupt change from the soft fine-
grained limestones of the Vicksburg group to the clays, sands and
phosphatic limestones of the Hawthorne formation. The relation of
the Hawthorne formation to the Alum Bluff formation has not yet
been accurately determined, though, at De Leon Springs, Chipola
'Dall, Wm. H., The Neocene of North America, Bull. U. S. Geol. Survey
No. 84, 1892, pp. 105-123.
'Dall, Wm. H. Neocene of North America, U. S. Geol. Survey, M,.Kt i.
1892, pp. 107, et seq.







FLORIDA STATE GEOLOGICAL SURVEY.


fossils have been found in a marl overlying phosphate rock which be-
longs to this formation. At various points in the peninsula of Flor-
ida the Hawthorne formation is found resting unconformably upon
limestone of Vicksburg age, and in the vicinity of Hawthorne thin
beds of conglomerate occur in the base of the formation. At many
of the phosphate mines in central Florida the limestones of the
Hawthorne formation are found overlying either the Ocala limestone
or the "Peninsular" limestone with an apparent unconformity, which
has permitted the deposition of sands and some limestone beds along
channels developed in the upper surface of the Vicksburg formations.
It should be said, however, that in many of these cases the materials
belonging to the Hawthorne formation appear to have been more or
less disturbed since their deposition, and it is possible that at some
localities the apparent unconformity may be due to the falling of the
roofs of caverns developed near the contact of the two formations.
The relation of the Hawthorne formation to the other members of the
Apalachicola group has not been determined, but there is no doubt
that its deposition was in part contemporaneous with the Tampa and
Chattahoochee formations. In fact, while the absence of paleonto-
logic information makes it impossible to correlate these formations on
biologic grounds there is little doubt that they were all deposited
during an extensive submergence which succeeded the emergence of
the rocks belonging to the Vicksburg group. On physical grounds,
therefore, there is good reason for regarding these formations as
synchronous.
Lithologic Character:-According to Dr. E. H. Sellards the rock
at the type locality at Hawthorne is a light-colored, soft, porous lime-
stone. The original building stone quarry, which is located near the
station of Grove Park, about three miles west of Hawthorne, is now
abandoned and is badly overgrown, so that the thickness of this lime-
stone cannot well be determined. At the old phosphate mine, which is
at least a mile southwest of the stone quarry, the rock is a phosphatic
conglomerate. At many localities the limestones of the Hawthorne
formation are silicified, forming boulders and beds of chert. This is
a very common condition in the rock phosphate region where these
limestones rest directly on those belonging to the Vicksburg group.
Beneath the phosphatic limestones of the Hawthorne formation are
beds of sand, sandstone, or gravel, which are underlain by several
feet of clay. The sand beds at some localities contain iron oxide which
forms a coating on the grains of silica. The clays are greenish and
locally sufficiently calcareous to be called a marl.
Thickness. The thickness of the Hawthorne formation varies
greatly, the maximum amounting to approximately ninety-five feet.
The three members of this formation with their mi. nn in R nls,-Icrg v






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


thicknesses, according to Dall,' consists of greenish clay'seventy feet,
ferruginous yellow sandstone four feet and phosphate rock twenty
feet. The maximum thickness of the Hawthorne formation, as given
by the same author, is 125 feet.2 However, over a large part of the
peninsula, where the sole representative of the Hawthorne formation
is the phosphatic or siliceous rock, the thickness is but a few feet.
Physiographic Expression: The Hawthorne formation seldom
has much influence upon the surface configuration in the region which
it underlies. Locally, however, the cherty beds protect the underlying
rock from erosion and thus give rise to ridges; and where the clays
lie near the surface they are characterized by an erosion surface of
moderate relief. The chert-capped ridges are usually inconspicuous,
-but in some parts of the phosphate region they are sufficiently marked
to form well defined topographic features.
Paleontologic Character:-The fauna of the Hawthorne formation
has received but little attention and is practically unknown. The green
clay and sands are reported to contain many oyster shells which are
thoroughly silicified, and the phosphatic limestones and the chert beds
are characterized by numerous specimens of an echinoid belonging to
the genus Cassidulus. Molluscan remains are associated with this
echinoid, but they have not yet been investigated.
Structure:-The Hawthorne formation has been affected by broad
earth movements similar to those which produced the peninsula of
Florida. There is a gentle seaward dip which is seldom noticeable in
single exposures, but may be determined by means of well records
which show that the formation sinks below sea level on the east coast.
There are probably dips 'both northward and southward from the
central part of the peninsula, but the determination of their amount
requires detailed study. The general easterly dips are known to be
irregular in amount, but probably do not average more than 75-100
feet to the mile.
Local Details:- While the Hawthorne formation is well known,
information concerning the detailed sections is comparatively meager.
The most complete sections which have been recognized as belonging
to this formation are those described by Dall.a At the type locality
near Hawthorne the rock is phosphatic and has been mined and
crushed for use as a fertilizer and at many other places the formation
contains more or less phosphate. One of these localities is at the
Devil's Mill Hopper northwest of Gainesville, where the rock is ex-

'Dall, William H., Neocene of North America; U. S. Geol. Surv. Bull. 84,
1892, p. 109.
'Ibid. p. 158.
'Dall, Wm. H., Neocene of North America, U. S. Geol. Survey Bull. 84.
1892, pp. 107-112.







FLORIDA STATE GEOLOGICAL SURVEY.


posed in the walls of the sink, which has a depth of about 115 feet.
Here the greater portion of the section belongs to the Vicksburg
group, but a phosphatic rock near the top probably represents the
Hawthorne formation. Another sink which exposes this formation
is located in section 18, T. 7 S., R. 18 E. At this locality the section
given by Datl' is:
This place is locally known as "Nigger sink," and the Vicksburg limestone
has been reached by a well hole in the center of it. Above the well the lower
10 feet of the wall of the sink is hidden by talus, but is believed to be clay of a
greenish-yellow color, 30 feet of which rises above the talus, covered by a
four-foot layer of firm, hard sand, almost a sandstone, and this by a sandy
ferruginous layer of clay and gravel containing an oyster, like 0. virginica,
reproduced in chalcedony. This ferruginous layer, which will be referred to
here under the term ferruginous gravel, seems to appear in many different
sections, with its oyster and silicified corals. It also occurs in Georgia. Above
it is a layer 2 feet thick of soft sandstone resembling the phosphatic rock in
appearance. Covering this is a bed of sand and clay 8 feet thick containing
fragments of all sizes, from a few pounds to a ton in weight, of the phosphatic
rock and its large, silicified coral heads. These last, when they appear on the
surface as around Archer, from the solution of the phosphatic matrix are
popularly known as "fossil stumps" or "nigger heads." They are large masses
of chert or chalcedony, often hollow, retaining on the surface more or less
obscure indications of the original coral structure. Above this stratum come
the surface sand and loam, here about 20 feet thick.
In this sink the well was drilled to limestone of the Vicksburg
group, but the depth and character of the material penetrated are not
given. The same writer gives more or less complete descriptions, of
several other sections.2 One of these is in Newnansville. where the
clay which immediately overlies the limestones of the Vicksburg
group has a thickness of seventy feet and is overlain by two feet of
ferruginous sand, three feet of undescribed material, and eight to
twenty feet of phosphatic rock. About five miles east of Mixon's the
ferruginous sand rests on the Vicksburg group and is overlain by the
phosphatic bed, and nearer Archer the remnants of the phosphatic
rock are found resting directly upon the Vicksburg. Occurrences of
similar phosphatic rock are reported where the railroad crosses the
Hillsboro River and at Jarves Springs; while at De Leon Springs a
phosphatic rock is said to be overlain by beds containing Chipola
fossils. The same phosphatic rock is also reported from Live Oak
and Lake City, and the ferruginous bed with its silicified oysters is
known to occur at Levyville and at Magnesia Springs. The following
sections are given by Dall:3

'Loc. cit. p. 109.
"Op. cit.
'Dall, Wm. H., Neocene of North America. U. S. Geol. Survey Bull. 84,
1892, pp. 110-111.







SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


At White Springs on the Suwanee, the following section was obtained:
I. Gray soil, sand, and humus ................................. 2 ft.
II. W hite sand ................. .... ................. ....... 4 ft.
IIl. Clay with silicificd corals and oyster (Hawthorne beds)...... 6-8 ft.
IV. Indurated clayey rock (Hawthorne beds?)................... 2 ft.
V. Clayey sand-rock, rather fine grained and soft................ 4 ft.
VI. The same, somewhat coarser and harder ..................... 8-10 ft.
VII. Sand rock of coarser sharp grains, coated and cemented to-
gether with white-limy matter .......... ................ 4-6 ft.
VIII. Foraminiferal Eocene top-rock (Vicksburg) indefinitely below.
The silicified corals of bed III are sometimes 20-60 pounds in weight and
along the river when dislodged from the clay often wear immense pot holes in
the softer lime rocks. Miocene sharks' teeth and fragments of bone also occur
in the clay. Under bed VIII, when it is tilted up, as occurs in various places
along the river, is found the older Orbitoides limestone of the Vicksburg group.
In a sink 4 miles north of Lake City, the following section was observed:
I, II. Sand and sandy soil ................. .................... 5 ft.
IV. Indurated clayey rock .......... ... ... ................... 2 ft.
VII. Lime cemented sand-rock ................................ 8 ft.
VIII. Foraminiferal Eocene (indefinitely down).
At White Springs numerous specimens of Cassidulus were obtained
from a cherty rock which has been used in constructing a foundation
for the spring house. According to reports, which were obtained from
well-informed residents of the town, this rock was quarried from the
river channel. At the time of the field investigations for this report
the river was too high to permit an examination of the outcrop in the
river channel; but a subsequent examination by Mr. Stephenson1 re-
sulted in finding the cherty beds of the Hawthorne formation in close
proximity to exposures of the Alum Bluff formation. This strengthens
the conclusion that was formed at the time of the earlier field work,
that the Cassidulus-bearing zone lies near the top of the Hawthorne
formation.
Two miles south of Lake City:
I. Sandy soil ..................... ............. .. ....... 2 ft.
III. Clay, with corals and oysters ........... ....... ......... 20 ft.
VII. Lime cemented sand-rock ................................. 3 ft.
VIII. Foraminiferal Eocene (indefinitely below).
Near the southern boundary of Columbia County, at Fort White, the rocks
are gently folded and the surface has been more or less worn into basins con-
taining phosphatic breccia of the older lime rocks, which are themselves under
these basins of phosphate slightly phosphatized in their upper portions. Here,
o\ring to the fact that the Miocene and Foraminiferal Eocene (Miliolite) beds
have been more or less broken up by the action of water dissolving or wearing
away the softer parts, the Orbitoides limestone sometimes immediately under-
lies the breccia in the basins and in other places the basins are composed of the
Miliolite limestone. Beds VI, VII and VIII, of the above series are more or

'Stephenson, L. W., Unpublished notes.







FLORIDA STATE GEOLOGICAL SURVEY.


less silicified, or when broken up the resulting breccia contains numerous angular
fragments of chert.
In the north-central part of the peninsula and extending as far
south as Croom, there are many exposures of chert and cherty lime-
stone which rest on the limestones of the Vicksburg group. This rock
usually contains many casts and molds of an Echinoid, which Vaughan
has identified as a Cassidulus. The rock appears to be very persistent
but seldom attains any great thickness. At Bass Station, about six
miles southwest of Lake City, it was quarried to a depth of twelve or
fifteen feet without reaching the underlying Vicksburg group. About
six miles west of Gainesville on the Newberry road, it appears to
have a thickness of more than fifteen feet and to rest directly on the
Ocala limestone, which forms the country rock of that region. The
same Echinoid is found in cherty beds in many localities between Bass
Station and High Springs and at Alachua sink, White Springs, Ella-
ville and Croom. It is also known at various localities in the hard
rock phosphate region. At the railroad trestle just west of White
Springs, there is an exposure of sands, marls and clay which is prob-
ably the local equivalent of the limestones belonging to the Hawthorne
formation. At this locality the beds pass under the Chipola marl
member. A section at the railroad trestle shows the following ma-
terials:
1. Sandy loam ............................... ........ ..... ... 20+ ft.
2. Soft friable marl containing some bands of chert and numerous
Echinoids ............................ ............ 10-15 ft.
3. Soft marl containing oyster shells.
4. Light green thinly laminated siliceous clay..................... 4 ft.
5. Light green sand to water ................................. 4+ ft.

Total ............. ................................ 44+ ft.
CIIATTAHOOCIHEE FORMATION.

The limestones and marls exposed along the Apalachicola River
have been grouped in various ways by different writers. In this paper
tlie name Chattahoochee formation is restricted to those limestones
and marls of northern and western Florida which lie stratigraphically
between the limestones of the Vicksburg group and the Chipola marl
member of the Alum Bluff formation. Beds of chert occur in this
formation and thin layers of sand and clay are not uncommon. The
type locality is at Chattahoochee Landing. where there is an exposure
of light gray marl and impure limestone. This formation forms
Langdon's' Chattahoochee group, and it -is apparently the Chatta-
hoochee group of Foerste.2
'Op cit.
SOp cit....










SECOND ANNUAL REPORT. IL. IV.


FIG. 1.-OUTCROP OF LIMESTONE OF HAWTHORNE FORMATION ON
SUWANEE RIVER, OPPOSITE ELLAVILLE, FLA.


FIG. 2.-LIMESTONE OF TAMPA FORMATION EXPOSED ALONG SIX-MILE
CREEK, ONE-FOURTH MILE BELOW A. C. L. R. R. BRIDGE, IIILLS-
BORO COUNTY, FLORIDA.

Digitized by Goo 0l


FLORIDA GEOLOGICAL SURVEY.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


In 1892 Dall" called this formation "Ocheesee beds." but in a
subsequent paper he notes the absence of exposures at Ocheesee2 and
uses the names Chattahoochee formation and Chattahoochee lime-
stone.4 As the formation contains considerable marl, the use of Chat-
tahoochee limestone is not entirely satisfactory, and hence the name
Chattahoochee formation is retained.
Stratigraphic Position:-The Chattahoochee formation is known
to rest unconformally on the underlying limestone of the Vicksburg
group in southern Georgia. The evidence upon which this uncon-
formity exists was summarized by Pumpelly in 1893." According to
this writer, there is usually a limestone conglomerate at the base of
the ,Chattahoochee formation in southwestern Georgia, and the alti-
tude of the contact between the two limestones varies considerably
within short distances. The variations in altitude given by Pumpelly
might, if considered alone, Le, regarded as due to deformation rather
than to an erosional unconformity, but the evidence of erosion is
strongly supported by the conglomerate which in some places resem-
bles breccia, but in other localities contains rounded pebbles of the
underlying rock. The difference in lithologic character between the
limestones of the Vicksburg group and the Chattahoochee limestones
is so marked that it would hardly be possible to mistake the source of
these pebbles. The argument in favor of the inequalities of the sur-
face of the limestones of the Vicksburg group being due to erosion
is strengthened by the paleontologic evidence. On evidence furnished
by Foerste, Pumpelly states that the Chattahoochee at Griffins Creek
contains a fauna characteristic of the upper part of the Vicksburg
group, while the other localities examined contain faunas belonging
to the lower part of that group. It thus appears that at Griffins Creek
the deposition did not begin until after the formation of the beds
exposed in the immediate neighborhood, or, in other words, that an
island consisting of the underlying limestones of the Vicksburg group
was not submerged until after the deposition of the lower part of the
Chattahoochee formation.
Tuomev also collected corals at the contact between the Chatta-
hoochee and the underlying limestones, and Dr. Dall identified these

Dall, Wi. If.. Neocene of North America, U. S. Geol. Surn. Bull. 84. 1892,
pp. 105-107.
*Dall, Win. H., and Stanley-Brown, Joseph. Cenezoic Geology along the
Apalachicola River, Geol. Soc. Am., vol. v, p. 154. 1894.
"Ibid, p. 152.
"Ibid, p. 155.
'Pumpelly, Raphael. An apparent time break between the Eocene and
Chattahoochee Miocene in southwestern Georgia. Am. Jour. Sci., 3rd ser., vol.
xlvi, 1893, pp. 445-448.






FLORIDA STATE GEOLOGICAL SURVEY.


as belonging to the base of the Miocene, to which the members of the
Apalachicola group were formerly assigned.
In Florida the base of the Chattahoochee formation was not seen,
but there is little doubt that the pronounced unconformity observed
farther north extends southward into that State. This view is
strengthened by what is already known of the physical history of the
State; and by the fact that both the Hawthorne and Tampa forma-
tions, which appear to have been deposited at about the same time as
the Chattahoochee, rest upon an eroded surface of the limestones of
the Vicksburg group.
Lithologic Character:-The Chattahoochee formation consists of
light-colored limestones and marls, containing some thin beds of chert,
clay and sand. The colors vary from creamy white to light gray or
green on recently exposed surfaces to light yellow, brown or more
rarely, pink, on weathered outcrops. Lithologically, there is a
gradation from nearly pure limestone to sands and clays, but, in gen-
eral, the argillaceous and siliceous limestones predominate, forming
impure limestones or marls. The formation is in part composed of
semi-crystalline limestone; but soft. loosely coherent rock resembling
an impure chalk is more common. While chert beds occur at various
horizons, they are much thinner and less persistent than those of the
underlying group. At times, organic life appears to have been
abundant, and hence some layers are very fossiliferous, though the
fossils are usually preserved in the form of imperfect casts and molds
which have been left by the solution of the shells.
Thickness:- Vaughan's' observations along the Apalachicola
River show that the Chattahoochee attains a considerable thickness
near the type locality.
The Chattahoochee limestone at the Old Landing has a thickness of at least
58 feet and probably is greater because the basal 20 feet of the two sections
measured on the roads to the water's edge at the river are not exposed. How-
ever, in all probability the alluvium bottom accompanying the river is underlain
by this formation, giving it a total thickness of slightly more than 100 feet.
Well borings from Quincy indicate that the thickness of the Chat-
tahoochee formation at that locality is slightly greater than 100 feet;
but here, as elsewhere, it is difficult to determine the exact thickness
of formations from well samples. The maximum thickness of the
formation is probably double the figure given above and it may even
be as great as 250 feet.
Physiographic Expression::-In general, the region underlain by
the Chattahoochee formation is one of high relief and well developed
surface drainage. However, this is not always due to the character
of the rocks of this group, for in the northern part of the State the
'Vaughan, T. Wayland. Unpublished notes.







SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


surface configuration is often determined, in part, by the character
of the superficial sands and clays of post-Oligocene age. The lime-
stones of the Chattahoochee formation are less soluble than those of
the underlying Vicksburg group; and, hence, they contain fewer un-
derground streams, which give a characteristic sink-hole topography.
However, underground streams, sink-holes and natural bridges are
by no means rare. Where the limestones belonging to the Chatta-
hoochee formation are thin the topography is often the combined re-
sult of solution of the Lower Oligocene limestones and the protection
of the ridges and hills by the more durable Upper Oligocene limestones.
Paleontologic Characters:-At some localities in southern Georgia
the basal layers of the Chattahoochee formation supply many corals'
and the lower part of this formation contains Orthaulax pugnax, a
gastropod which is characteristic of the "silex bed" at Tampa. This
locality has been studied by Vaughan,2 whose description emphasizes
the existence of an erosion interval between the deposition of the
Vicksburg and Apalachicola groups, and shows the existence of a
fossil coral reef. Of this coral reef, Vaughan says:
My estimate is that there are between twenty-five and thirty species.
This is the richest fossil coral fauna known from any one locality of the
Continental North American Tertiaries. However, the state of preservation of
the specimens is not always satisfactory, and it may not be possible specifically :o
describe all of them.
The particular interest of this fauna does not lie in its richness, but in its
geologic import. The Tertiary coral faunas of the United States below the
Chipola horizon were very isolated, no species from the continent, excepting the
Orbicella mentioned, being found in any other area. This fauna is distinctly
Antiguan in types. Besides the Orbicella referred to, there is a very large-celled
Orbicella, very close to O. crassilamellata (Duncan), if not identical with that
species, found abundantly at Russell Spring. An Astrocoenia is extremely close
to A. ornata of Duncan from Antigua. The same remark will apply to the
Stylophora and Alreopora.
From this field examination it appears that the reef corals of the Antiguan
marls and cherts can be correlated with the base of the Chattahoochee limestone,
the base of Dall's upper Oligocene. It is also quite probable that the Oligocene
reefs in the vicinity of Lares. Porto Rico, and of Serro Colorado, Curacao, re-
present the same horizon. The Bowden, Jamaica, fauna would be slightly
higher, to be correlated with the Chipola fauna.
It is evident that this coral fauna from Russell Spring, besides filling a gap
in the faunal succession on the continent, furnishes a basis for correlating many
of the West Indian fossil reefs with the continental Tertiary section, and we
may confidently expect more light upon the correlation of American and
European horizons.

SPumpelly. Raphael. An apparent time break between the Eocene and Chat-
tahoochee Miocene in southwestern Georgia; Amer. Jour. Sci., 3rd ser., vol. xlvi,
1893, pp. 445-447. See Vaughan, Science 1900.
'Vaughan, T. Wayland. A Tertiary Coral Reef near Bainbridge, Georgia.
Science, N. S., vol. xii, 1900, pp. 873-875.






FLORIDA STATE GEOLOGICAL SURVEY.


One interesting feature of these corals, not already mentioned, is that they
apparently bring the fauna of Vicksburg, Mississippi, into closer relation with
the succeeding faunas. A great deal is shown regarding the succession and
interrelations of the faunas of the continent itself.

A bed in the lower part of the Chattahoochee formation usually
contains an abundance of Echinoids, and several different genera be-
longing to this group are known to occur in other horizons. At a
horizon about twenty feet above the echinoid bed there is a layer
containing an abundance of gastropods belonging to the genus Helix,
and a slightly higher horizon is characterized by numerous specimens
of Cerithium. Among the fossils collected from this limestone are :

Pyraiisinus cornutus. V. cancellata.
Cerithium hillsboroensis. V. penito.
Potamides transecta. Cytherea nuciformis.
Conus planiceps. Cyrena vesica.
Natica amphora. Orbitolites floridanus.
Lucina hillsboroensis. Tagelus undet.
Cardita serricosta. Solen undet.
Venus stamina.

Structure:-In northwestern Florida the limestones of the Chat-
tahoochee formation dip toward the south. The exact amount of this
dip is difficult to determine, but careful estimates by Miss Maury,
based on sections made by Harris, places the average descent at
twenty-three feet per mile. The same writer has noted a variation in
the rate of dip, as will be seen from the following quotation:

That this dip is steeper toward the north is shown by the following rate of
slope:
Aspalaga to ravine ........................1-8 mile, 10 feet, or 80 feet per mile.
Aspalaga to Camp Scott .................. 2 miles, 70 feet, or 35 feet per mile.
Camp Scott to Rock Bluff .....'............. 3 miles, 48 feet. or 16 feet per mile.

Local Details:-The Chattahoochee formation, which is best ex-
posed along the Apalachicola River, has been described by a number
of writers. At Chattahoochee, according to Dall, the major portion
of the rock exposed belongs to the Alum Bluff formation. His most
complete section, which was made on the road running north from
Chattahoochee Landing, is given below.2

SDall, Wm. H., and Stanley-Brown, Joseph; Cenozoic geology along the
Apalachicola River; Bull. Geol. Society of Amer., vol. v, p. 153, 1894.
*Dall, Wm. H. and Stanley-Brown, Joseph. Cenozoic geology along the
Apalachicola River, Bull. Geol. Soc. of Amer., vol. v, 1894, p. 152.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


Sections at Old Chattahoochee Landing.
Feet.
1. Reddish sand and gravel, with streaks of clay.................... 20 to 40
2. Grayish yellow friable marl, with harder layers................ 20
3. Greenish clayey marl, very adhesive ......................... 2
4. Chattahoochee limestone, with fossil casts...................... 4
5. Talus to water's edge, about ................................ 3

Total thickness ...........................................49% to 69%

This section was taken on the road running northeast from the landing.
Feet.
1. Reddish sands, gravel and clays............................... 15 to 20
2. Grayish yellow marl, friable ................................. 20
3. Greenish clayey marl, sticky ............................ 2%
4. Talus to W ater's edge, about ................................. 3

Total thickness ...........................................30% to 45 2

Section number 2 was taken on the road which runs about southeast from
the landing. The exposures are mostly in the gullies.
The fossil-bearing bed is number 4, and contains, among other fossils,
echinoids, Pecten (Chipola sp.), Area (like transversa), large solitary coral,
Venus penita, Lima (like scabra), Hemicardium, Ostrea, Loripes, Scala, Plicat-
ula, Divaricella, Pyrazisinus, Phorus, all as poor casts; fish bones and ribs of
some mammal resembling those of the Manatee. No orbitolites were seen.

From the correlations made by Dall it is apparent that he regarded
No. 1 of the above section as Lafayette and Nos. 2 and 3 as Alum
Bluff. A generalized section made by Vaughan1 from Chattahoochee
Landing to Chattahoochee postoffice, is given below:
Thickness.
Feet. Inches.
3. Red sands with some gravel. Toward the base becoming more
argillaceous sometimes composed of mottled red sands
and bluish or purplish clays. The basal portion forms a
mantle following quite closely the contact with the Alum
Bluff formation ...................................... 50
The mottled basal portion extends through a vertical
distance of about 40 feet.
2. White chalk and clays sometimes greenish or bluish. The
greater portion of these clays are calcareous and a con-
siderable portion is argillaceous limestone in harder and
softer ledges. A calcareous specimen (chalky) was taken
70 feet above the water's edge of the river. The clays are
jointed and show conchoidal exfoliation. The lower por-
tion of this exposure does not appear to be calcareous.
Some fine sands at the bottom. Thickness.............. 5o
Rocks of the same character, either clay or limestone, as
that described above, occur 100 feet above the river. The


'Vaughan, T. Wayland. Unpublished notes.






FLORIDA STATE GEOLOGICAL SURVEY.


total thickness of the Chattahoochee formation here ex-
posed is 80 feet.
1. Alluvium of river bottom composed of reddish sands along
the river, thickness ..... ........... .................. 20
No exposure of beds beneath the river alluvium was seen.

Total ...... ......... ....................... .. 120

In commenting upon this section, Vaughan says:
It is evident that I did not examine the specific locality described by Dall,
for I did not see his Chattahoochee limestone. The upper part of his No. 2
is the lower part of my No. 2. From Dall's description the whole of my No. 2
would be referable to the Alum Bluff. The combination of his section and mine
gives a thickness of over 80 feet. His maximum thickness is 67 feet

The following more detailed section by Vaughan shows the char-
acter of the rocks exposed in the lower part of the section given
above.
Feet. Inches.
3. White argillaceous chalk in harder and softer layers......... 46
2. Very calcareous blue clay.................................. 2
1. Indurated calcareous clay stained yellow in places............ 15 3
Six feet 6 inches above the base is a fine-grained, very
calcareous marl white or slightly tinged with yellow in
spots. This stratum contains casts of many shells, etc.

Total .............................................. 63 3

At Wiley's Landing on the Chattahoochee River, about seven miles
above River Junction, Vaughan obtained the section given below, but
it has not been correlated with the other sections farther down the
river.
Section of bluff at Wiley's Landing. Thickness.
Feet. Inches.
7. Red clay ................. ....... ..................5 or 6
6. Limestone .................................... ..... ...... 25
5. Not definitely exposed, clay or limestone, probably limestone
or calcareous clay ..................................... 5 6
4. Limestone containing a large oyster, Isocardia. Venus,
Pyrula, etc. ........................................ 5 6
3. Unexposed surface red clay, apparently underlain by lime-
stone ........................... ..... ....... ........ 11
2. Bluish sticky clay .......................................... 5 6
1. From water's edge to 5 feet 6 inches not definitely exposed,
but apparently bluish sticky clay. There is much lime-
stone detritus over the surface, it having rolled down
from the upper part of the bluff. Thickness............ 5 6

The surface of this bluff is so covered by red clay and talus from above
(limestone pebbles and boulders) that it is not possible to discover the details
of the section. The basal 11 feet are argillaceous while the succeeding 47 feet
are for the most part limestone. But the rock is so indurated that the fossils







SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


can scarcely be freed from the matrix. In one portion of the limestone horizon,
the lower 25 feet, very large oyster shells are abundant. These weather out in
good condition, probably because their matrix is argillaceous or because the
limestone is softer. The greater portion of the limestone is hard and rings
under blows of the hammer.
No fossils were found in the basal argillaceous layers. These lower layers
would, according to the literature, probably be referred to the Vicksburg. The
limestone belongs to the Chattahoochee. The lithologic specimen of it was taken
from the top of the exposure and a fair number of fossils were collected. The
exposure was also photographed. This section was measured by a hand-level.

The following descriptions were also furnished by Vaughan:

Section, Aspalaga Landing. Thickness.
Feet. Inches.
5. Sand ................................................ 27 6
4. White lime rock. The surface appearance and color are those
of chalk. This rock is indurated in thick, massive ledges
and fragments show concentric exfoliation. Its color is
originally bluish and becomes white upon drying......... 39 6
3. Chalky limestone more calcareous in the basal portion.......18-20
2. Friable limestone containing patches of blue clay and very
poor remains of fossil mollusks ........................ 1 4
1. Whitish tinged yellowish chalk which when kneaded in the
water forms a whitish sticky paste. The stratum is
sufficiently indurated to form a ledge and extends at least
1 foot below the surface of the water. Thickness........ 7 8
The argillaceous basal portion of stratum No. 3 is about 2 feet, then fol-
lows a chalky stratum and bluish clays at the base of No. 4.
At the extreme upper end of the bluff the exposure is more satisfactory.
The bluff face (Nos. 1, 2, and 3, and the lower 10 feet, 8 inches of No. 4, total
thickness 30 feet 5 inches) is white chalk with layers of more or less friable
and argillaceous marl. Fossils are very numerous and several layers of the
chalk especially in stratum No. 2 and at the top of the bluff face, but all are
miserably preserved, there being no shell substance left, only casts. Nucula,
Pecten, Venericardia, Lucina, Isocardia, Meretrix, Turritella, Stylophora solitary
corals, etc., were observed.
A resume of the exposure at Aspalaga excluding the surface sands, is as
follows:
Feet. Inches.
4, ............................................ ............. 39 6
3, ...................... ..................... ................ 11
2, ..................... .................. .................. 1 4
1, .................................................... 7 8

Total thickness ......................................... 5 6
(Or roughly, 60 feet.)
The whole of these 60 feet (perhaps excepting some marl beds near the
top) is chalky limestone. This section was-measured with a hand-level.
I could not find the marl bed described by Dall and think it must have been
simply a disintegrated chalky stratum or weathered chalk as the weathered chalk
is frequently a clay marl. The limestone was sectioned at two pl3ce?. one near







FLORIDA STATE GEOLOGICAL SURVEY.


the lower end of the bluff; the measurements were by hand level and steel tape;
the uppermost exposure was a ledge and the thickness as has already been stated
was 59 feet 6 inches, or roughly, 60 feet.
Near the upper end of the bluff an aneroid section was made and 55 feet
was the thickness by that measurement, practically the same as the preceding.
Coming down the road to Aspalaga Landing is an exposure just before
passing to the river bottom. To the right of the road is a small branch that
empties into the Apalachicola at Aspalaga Landing. The Chattahoochee forma-
tion forms an escarpment a few feet high along the northern side of the branch.
An aneroid measurement from the water's edge to the highest exposure on the
road gave a thickness of 35 feet, that is, only a portion of the limestone is there
exposed.
At the crossing of the River Junction-Bristol Road, over (Flat Creek?)
is an exposure of limestone of small extent, probably the Chattahoochee.

Tests with acid of specimcns from Aspalaga Bluff.

Stratum 4. Specimens from highest exposure effervesces.
Specimen from chalk ledge in face of bluff effervesces.
Stratum 3. Clay, just beneath base of No. 4, considerable effervescence. Very
calcareous, stiff blue clay effervesces strongly.
Stratum 2. A friable limestone, containing considerable clay.
Stratum 1. Is an argillaceous limestone, chalk.

Section western end of trestle cast of River Junction, Mile-post 206.
Thickness.
Feet. Inches
(7.) 4. Soil and humus .................................... 1 6
(6.) 3. Gray sands ........... .......... ......... ....... 3
(5.) 2. Stiff, mottled sandy clay ........... ................. 3
(4.) 1. Stiff, non-calcareous blue clay....................... 3 2

Total ............................................... 10 8
(Section measured with steel tape.)
Immediately below (4) 1, of the preceding section and nearer the Creek.
Thickness.
Feet. Inches.
3. Sandy, ferruginous clays containing black, apparently carbon-
aceous particles. Stratum mottled yellowish or brown, *
and bluish white with black spots ..................... 3
2. Stiff blue clay with lumps or seams of white clay............. 1
1. White, sandy, non-calcareous clay oxidizing yellowish or brown
on surface ........................................ 3 6

The barometer readings correlate these clays in altitude with those im-
mediately back of the station house at River Junction and as they are similar
in character this correlation is apparently trustworthy.
One telegraph pole west of milepost 205 is an exposure of the argillaceous
chalk of the Chattahoochee 2.7 feet in thickness. It is overlain by the dump
from the railroad excavation. The material was tested with acid and found to
be calcareous. It has the appearance of the usual limestone of the '-h i-hA:h<<






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


The surface shows irregular joints and conchoidal or concentric exfoliation.
One imperfect fossil was found, a surface cast, probably a Lucina.
This locality is about 23/ miles east of River Junction railroad station on
the Seaboard Air Line Railway. River Junction is at mile-post 208, 208 miles
from Jacksonville.
From looking along the railroad this exposure seems to be topographically
lower than the two preceding exposures.
Excepting the two exposures described, there are none between this locality
and River Junction excepting surficial sands and may be some red sands or
clays and sands. There are no deep cuttings along the railroad track.


Section at Station House, River Junction.


Te
Fee;


Chocolate or brownish soil............ .. ....................... 1
Sandy whitish clay ................... ...... .......... 1
Sandy whitish clay slightly calcareous in ledges.................. 8


sickness.
t. Inches.

6


Total ................... .............. .................. 10 6


Section near lower end of train yard.
Feet.
Humus and blackish or dark brown soil, about............... 1
Yellow sandy clay or marl, estimated ...................... 3
Whitish sandy clay, very slightly calcareous ................. 4
Whitish sandy clay (very slightly or not at all calcareous).... 4
More calcareous white sandy clay........................... 1


Inches.


7


2. Very calcareous sandy clay................................. 1 5
1. Sandy chalk very argillaceous, sand grains fine................ 6 5

T otal ..................... ..................... 21 7
1, at edge of sand flat of small branch. This last bed is the one from which
Dall mentioned fossils. I found as poor casts, Isocardia, Hemicardium, Ven-
ericardium, Tagelus, Turritella (very large species) cast of inside of large
gastropod (Orthaulax?), smaller gastropods, etc. There were many specimens
and many species but all poorly preserved.
Between River Junction and the railroad bridge over the Apalachicola River,
there are no rock exposures except the one already mentioned.

Ditch running east from back of Station House at River Junction.

A few yards east of the wagon road crossing the railroad there is a small
fall in this ditch and here a number of fossils were obtained:


Mammalian ribs, fragments. (These
ribs are probably of the manatee.)
Large Chelepod crustacean claws,
the animal apparently the size of
a large lobster.
Cardium, several species.
Hemicardium.
Venericardia.
The shells are all casts, internal or


Pecten.
Venus.
Lucina.
Astarte.
Natica (very large species).
Orthaulax?
Fusus.
Cerithium or Turritella.
external, but the fauna is evidently


typical Chattahoochee. One fine regular Echinoid was collected.






FLORIDA STATE GEOLOGICAL SURVEY.


Cement Quarry one-half mile south of River Junction. Thickness.
Feet. Inches.
8. Superficial coating of black humus and some gray sand......
7. Friable chalky limestone forming slope of hill............... 13+
6. Harder chalky layer ....................................... 5
5. Softer chalky layer ....................... ............... 1 5
4. Harder, somewhat saccharoidal limestone.................... 9
3. Softer fossiliferous chalk .................................. 1 7
2. Harder limestone with numerous fossils, the commonest the
Hemicardium and an orbitoid foraminifer. This material
when weathered turns reddish and forms a residual red
clay. No original molluscan tests were observed, but they
are sometimes replaced by crystalline calcite............ 1 3
1. Soft white chalk, indurating upon exposure, used in making
cement brick ...................... ............... 4
According to the barometer, the base of No. 1 is 50 feet above the railroad
at River Junction.
Some twelve to fifteen feet of limestone belonging to the Chatta-
hoochee formation is exposed at Rock Bluff, and it doubtless under-
lies the Chipola marl member at Alum Bluff. On the Chipola River
the same limestone is exposed at intervals from near the mouth of
Ten-mile Creek northward to beyond the Peacock Bridge. These ex-
posures seldom exceed four or five feet in thickness and the rock is a
chalky limestone similar to that exposed on Apalachicola River. The
outcrops at Peacock and Willis bridges on the Chipola River were
visited, but they proved to be nearly destitute of organic remains.
This limestone, doubtless, forms the natural bridges over Ten-mile
and Sinking Creeks, tributaries of the Chipola River, but high water
prevented a close examination of these localities. Similar limestone
occurs in the form of loose bowlders in the vicinity of Knoxhill, Wal-
ton County, and outcrops of it are reported on the Choctawhatchee
River, south of the Louisville and Nashville Railroad bridge. At
Caryville, the well of the Wood Lumber Company penetrated eight
feet of pinkish limestone, which doubtless belongs to the Chattahoochee
formation. The limestone at St. Marks and at some localities farther
north and east is also tentatively referred to this formation.

TAMPA FORMATION.

The Tampa formation consists of greenish clays, light gray to
yellow limestones, and a very fossiliferous bed of "silex." Hitherto,
the "silex" and a portion of the limestone have been all that was known
of the formation. The "silex beds" and limestone of the Tampa forma-
tion were first examined by Conrad' over sixty years ago. In the
Conrad, T. A., Observations on Eocene formations and descriptions of
105 new fossils of that period from the vicinity of Vicksburg, Miss.; Phila. Acad.
Science Proc., vol. iii, p. 28.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


same year Professor Allen1 described both the limestone and "silex
bed" at Tampa, and his account of these beds has been generally ac-
cepted as correct. The same locality was subsequently visited by
Tuomey.2 In 1884, Kerr and Mitchell3 visited Tampa and noted the
replacement of fossiliferous limestone by chalcedony in what has since
been called the "silex bed." Ballast Point, near Tampa, where the
"silex bed" is best exposed, is the locality where Bailey4 found, what
he regarded as infusorial earth, resting on the "silex bed." Later in-
vestigations have shown that this material is merely a residual ma-
terial produced by the action of the weather upon the silicified lime-
stone.
In 1887, Heilprin5 published an account of the explorations near
Tampa and called attention to the fact that the fossil which Conrad
regarded as a nummulite is really an orbitulite. Heilprin gave a brief
description of Ballast Point and other exposures near Tampa, but
does not appear to have recognized the relations between the lime-
stone and the "silex bed." Later publications by Dall give more com-
plete descriptions of the Tampa exposures and show clearly that there
S are two horizons represented which he has called respectively "Tampa
silex bed" and "Tampa limestone." Because the "silex bed" is char-
acterized by the presence of Orthaulax pugnax, Dall has called it the
"Orthaula. bed" and the limestone has been designated "Cerithium6
rock," on account of the presence of many specimens belonging to that
genus.
In his bulletin on the Neocene of North America, DallF'described
the "Tampa group," including what he designates the Tampa, Chipola
and Alum Bluff beds. But the subsequent discovery of Orthaulax
pugnax in the Chattahoochee led him to place the "silex beds" in his
"Chattahoochee group."8
While engaged in the field work for this report, additional informa-
tion concerning the rocks at Tampa was obtained. Stated briefly, the
observations showed the presence of a limestone below the "silex bed"

'Allen, Prof. John If. Amer. Jour. Sci., 2nd ser., vol. ii, 1846, pp. 36-48.
'Tuomey, M. Notice on the geology of the Florida Keys and the southern
Coast of Florida. Am. Jour. Sci., 2nd ser., vol. ii, 1851, pp. 390-394.
SKerr, W. C., and Mitchell, Elisha. Scientific Society, 1884-5, p. 87.
'Bailey, J. W. Microscopic Observations, Smithsonian contributions lo
knowledge, vol. ii, No. 8, 1850, p. 10.
'Heilprin, Angelo. Explorations on west coast of Florida; Wagner Free
Institute of Science Trans., vol. i, 1887, pp. 10 and 11.
'Dall, Wm. H. Neocene of North America, U. S. Geol. Survey, Bull. 84,
1892, pp. 112-113.
'Loc. cit.
'Dall, Wi. H. Tertiary fauna of Florida; Wagner Free Institute of
Science Trans., vol. 3, pt. 6, 1893, pp. 1564 and 1565.






FLORIDA STATE GEOLOGICAL SURVEY.


and the existence of clay beds at both the base and top of the forma-
tion. The limestone below the "silex bed" is similar to what Dall has
called "Cerithium rock," and in this connection it is interesting to note
what he has said concerning its existence:
From these observations it appears that, while the existence of a Cerithium
rock under the Orthaulax bed is a priori probable, sufficient evidence of its
existence is still to be collected, and the rock identified as such by Heilprin
may very possibly have been a portion of the Tampa limestone.

Since the publication of the report from which this quotation is
taken, a series of wells have been drilled, and the samples which
were preserved show the presence of the limestone below the silex.
Stratigraphic Position:-Evidence of an unconformity at the base
of the Tampa formation was obtained in drilling wells for the city of
Tampa. The log of one of these wells is given on page 89, and it
will be noted that after passing through thirty feet of limestone and
chert the drill encountered a blue clay forty-one feet in thickness.
The limestone and chert represent the limestone and "silex bed" of
the Tampa formation and the clay appears to belong at the base of
that formation. At a distance of 200 feet from the well mentioned
above, the clay was encountered at about the same depth and was said
to have a thickness of sixty-four feet. This variation shows that the
underlying limestones of the Vicksburg group have an irregular sur-
face which was doubtless produced by erosion.
The relation of the Tampa formation to the Hawthorne and Chat-
tahoochee formations has already been discussed, and its stratigraphic
relation to the Alum Bluff formation is probably similar to that of the
other two formations mentioned. The post-Oligocene formations,
which occur in the area where the Tampa formation is known, rest
unconformably upon it.
Lithologic Character:-The upper member of the Tampa forma-
tion comprises a well stratified greenish clay containing some calcare-
ous nodules and thin beds of limestone near the base. Scattered
throughout the clay are many silicified corals, some of them having
a diameter of two or three feet. The clay is very plastic and hence
is valuable for the manufacture of brick. Beneath this clay is the
light-gray to yellow limestone which was formerly called the "Tampa
limestone." The "silex bed' represents a silicified zone in this lime-
stone and is, therefore, a zone of replacement. This is well shown
by some of the fossils which have been only partially silicified; and
by the presence of more or less unaltered carbonate of lime in the
original rock. Small nodules of chert occur at other horizons in the

'Dall, Wm. H., Neocene of North America, U. S. Geol. Survey, Bull. 84,
1892, p. 119.






SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


limestone, and outcrops of the rock are often denser and harder than
exposures in quarries. Locally the limestone is hard enough to make
a durable building stone which might be useful in the construction of
foundations for buildings. Fossils are abundant in some parts of the
limestone, but they are largely represented by casts and molds, which
have been left by the solution of the original shells. The "silex bed"
contains numerous fossils which have been wholly or partially replaced
by chalcedony. Resting upon the "silex" at some localities is a
siliceous residual material which was formerly thought to be infusorial
earth, but is now known to be weathered material derived from the
underlying rock. In such cases the action of the percolating water has
removed the matrix, leaving many beautifully preserved pseudomorps
and casts of shells. These fossils are commonly composed of chal-
cedony which frequently exhibit the characteristic markings of the
original shells. (See Fig. 2, Plate IV.)
Beneath the limestone beds is a greenish clay which commonly con-
tains a considerable admixture of sand. This clay is very plastic and
resembles the clay which overlies the limestone. Judging from well
records, the deposit is homogeneous, but there is a possibility that the
sand contained in the well samples may be derived from thin sand
partings in the clay bed.
Thickness: The information concerning the thickness of the
Tampa formation is meager, but it is sufficient to fix the maximum
thickness at more than 130 feet. The clay bed at the top of the for-
mation has a known thickness of fifteen feet. The limestone between
the "silex bed" and the upper clay is about forty feet thick. The
thickness of the "silex bed" varies considerably, ranging from about
four feet to more than ten feet. Beneath the "silex bed" is a lime-
stone which has a known thickness of six feet. The clay bed at the
base of the formation has been penetrated by two wells within 200
feet of each other, and the thickness varied from forty-one feet to
sixty-four feet.
Physiographic Expression:--The area underlain by the Tampa
formation is so near sea level that no marked physiographic features
can be discerned. The influence of the limestone of this formation is
seen in the rapids of the Hillsboro River; and it may be the solution
of these limestones which gives rise to some of the depressions north-
east of Tampa. Aside from these minor features, the surface of the
formation is not very diversified.
Paleontologic Characters:-In addition to the characteristic Or-
thaulax pugnax, the "silex bed" of the Tampa formation has fur-
nished a very large number of species, including some corals, many
species of gastropods, pelecypods and a few specimens of Orbitolites
floridanus which becomes abundant in the overlying i .. i'-.- At






FLORIDA STATE GEOLOGICAL SURVEY.


Ballast Point the fauna of the "silex bed," though largely marine, con-
tains many fresh water shells which were probably supplied from some
lakes or lagoons situated near the shore. The complete list of the
fossils from the "silex bed" is given by Dall, who says:'

About forty-nine per cent of the species in the Orthoulax bed are peculiar
to it, and very few of the more minute forms which should be present in such
a fauna are known. The relations of the fauna are most intimate with that
of the Oligocene beds above it, the Orbitolite or Tampa limestone, the Chipola.
and the Oak Grove sands. With either of these the percentage of species
common to both is more than twice as great as with any of the beds below,
such as the nummulitic, the Peninsular limestone, or the Vicksburg. But it must
be admitted that the faunas of all these, except the last, are very imperfectly
known. With the faunas of the horizons above the Oak Grove sands, there is
little in common, though in the tropical waters of the Antilles, about eight per
cent of the species are believed to survive to the present day. Only about 2.6 per
cent survive except in tropical waters.
One of the most interesting features of the fauna is the assembly of land
shells, which are southern immigrants and have left no survivors on the Am-
erican continent at the present day, though representative species occur to the
southward.

The fauna of the limestone in the Tampa formation contains fewer
species than that of the "silex bed," but the faunas are closely related,
as will be seen by the following quotation which' contains Dall's com-
ments on the list of fossils from these two beds:2

Total, ninety-five species, of which thirty-six are uncertain specifically, leav-
ing fifty-nine identified, of which thirty-seven are common to the silex beds, ten
are peculiar to the Tampa limestone horizon, four are known from the Ocala
nummulitic limestone, and two appear in the Vicksburgian, the Jacksonian, and
the Claibornian. One species (and probably more not yet discriminated) sur-
vives into the Chipola and two are believed to persist to the recent fauna.

Structure:-The Tampa formation lies near sea level and hence
it is difficult to get sections which show the structure of the beds.
Apparently the formation is nearly horizontal with a slight seaward
dip. While the formation may be affected by gentle flexures, the
evidence is still too meager to show their existence.
Local Details:-The "silex bed" of the Tampa formation is best
exposed at Ballast Point where it rises only a few feet above tide. At
this locality the maximum thickness of the bed is not shown. Dall's3
section at Tampa is:

'Dall, Win. H., Geological results of the study of the Tertiary fauna of
Florida; Ex. from Trans. Wagner Free Institute of Science, Phila., vol. iii,
Part vi, p. 1565, 1903.
SIbid, p. 1572.
'Dall, Win. H. Neocene of North America, U. S. Geol. Survey, Bull. 84,
1892, p. 113.







SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


White sand ................................................. 6 to 24 inches.
Yellow sand ................................................ 6 to 36 inches.
Pliocene breccia ............................................. traces.
Tampa limestone ............................................ 10 to 15 feet.
Tampa silex bed ............................................ 6 to 10 feet.

In drilling wells at the Tampa water works, between Sixth and
Seventh avenues, the "silex bed" was found to have a thickness of
only four feet. Beneath the "silex bed" there was a thin bed of lime-
stone underlain by greenish clay, which varied in thickness from
forty-one to sixty-four feet. The log of one of these wells follows:

1. White Pleistocene sand ...................................... 2 feet.
2. Tough yellow clay with no sand, residual clay ................... 10 feet.
3. Soft limestone which disintegrates readily-"Tampa limestone"... 14 feet.
4. Chert, "Tampa silex bed"....................................... 4 feet.
5. Soft limestone closely resembling No. 3 ......................... 6 feet.
6. Tough plastic greenish sandy clay ............................. 41 feet.
Base of the Tampa formation:
7. Chert ................. .......................... 2 feet.
8. W hite m arl ................................ ... ......... 6 feet.
9. Soft limestone ...................... ...................... 6 feet.
10. Very light colored hard rock................................. 15 feet.
11. Very hard dark yellow limestone............................... -6 feet.
12. Gray porous limestone with some water ........................ 15 feet.
13. Cherty beds ........................ ..................... 14 feet.
14. Darker limestone.
15. Gray plastic clay.
16. Hard yellow rock with chert.
17. Gray porous rock, water-bearing.
18. Like preceding.

Nos. 3-6 inclusive represent the Tampa formation, but at this lo-
cality the upper clay and a portion of the limestone have been re-
moved by erosion.
Another well 200 feet away encountered sixty-four feet of No. 6.
which suggests an unconformity at base of this bed, and this hypothe-
sis is strengthened by the fact that the rock immediately below the
clay differed in the two wells.
The upper clay bed of the Tampa formation is best exposed at the
pit of the Tampa Brick Company on the bank of the Hillsboro River
five miles northeast of the city. At this locality there is an exposure
of from ten to fourteen feet of light green siliceous clay which is
unconformably overlain by from two to four feet of light-gray Pleis-
tocene sand. The clay is very plastic and is said to make excellent
brick. Scattered throughout the deposit are numerous cobbles and
boulders of chert which represent silicified corals. While the major
portion of the exposure is of a light greenish color I.v.w.i Ilth b-. ,-ion







FLORIDA STATE GEOLOGICAL SURVEY.


of the pit, the clay becomes gray and is interbedded with thin nodular
layers of limestone.
A light green siliceous clay similar to that described above was
seen on the west side of Old Tampa Bay, near Safety Harbor (Espir-
itu Santo Springs). Here the section shows four to six feet of white
Pleistocene sand resting unconformably upon six feet of greenish
clay. On the beach, near this exposure are several large chert bould-
ers which were probably derived from beds beneath the clay. About
one mile north of the postoffice the following section was observed:
White Pleistocene sand .......................................... 2-4 feet.
Dark brown sand, partially indurated.............................. 1-6 feet.
Light greenish clay, thinly laminated.................................... 5 feet
On the Gulf coast, near Clearwater, are numerous exposures of
cherty limestone which are probably to be correlated with the rocks
at Tampa, but in the absence of paleontologic evidence, this correlation
must be regarded as merely tentative. A generalized section at this
locality was obtained from well records and observations along the
beach. *
1. White Pleistocene sand .................................. 12 feet.
2. Light colored clay ....................................... 14 feet.
3. Light colored limestone with chert concretions .............. 1 ft. to 6 in.
4. Bluish laminated marly clay with chert concretions............ 2-4 feet.
5. Light gray limestone with chert concretions................... 2-3 feet.
A generalized section near Laporitieres Spring is given by Dall:'
Humus, yellow sand, etc. .................................... 6 to 36 inches.
Tampa limestone ................. ........................ 10 to 15 feet.
Orthaulax bed ............................................. 7 in. to 10 ft.
The limestone of the Tampa formation is exposed near the pump-
ing station, where it has been quarried to a depth of over fifteen feet,
and other exposures occur at intervals along the Hillsboro River for
a distance of over fifteen miles inland. Probably the best exposures
are in the excavations near the Sulphur Spring, northeast of Tampa,
and at the rapids about a mile above the spring. The same limestone
was observed resting on the "silex bed" at the railroad crossing over
Six-Mile Creek. Here the limestone is immediately overlain by fos-
siliferous Pleistocene shell marl which grades upward into coarse
white sand.
Section one-eighth mile below railroad bridge--Orient (Tampa).
4. Soft white marl ................................................. 6 feet.
3. Light gray to buff fine grained quartz sand....................... 3 feet.
2. Gray shell marl Pleistocene .................................... 1-2 feet.
1. White soft limestone with some gastropods and other fossils....... 5 feet.
'Dall, Win. H., Neocene of North America, U. S. Geol. Survey, Bull. 84,
1892, p. 108.







SECOND ANNUAL REPORT-STRATIGRAPHIC GEOLOGY.


No. 2 rests unconformably upon No. 1 and is a thin but persistent
bed.
Section at railroad bridge-Orient (Tampa).

5. Fossiliferous white sand ......................................... 2 feet.
4. White marl ........................... ......... .... 6 feet.
3. Light gray sand ............................................. 1 foot
2. Gray shell marl ...................................... ..... 0-1 foot
1. Gray to yellow limestone, very fossiliferous in places............ 6 feet.

No. 2 rests unconformably upon No. 1 and is evidently the same
horizon as No. 2 in the preceding section. The limestone in both of
these sections is what has commonly been called "Tampa limestone."
In the section at the railroad bridge, there is some "silex" near the
base and this evidently represents the same horizon as the "silex bed"
at Ballast Point.

ALUM BLUFF FORMATION.

The name Alum Bluff formation as here used includes those beds
which belong stratigraphically between either the Chattahoochee for-
mation or the Hawthorne formation and the marls and limestones of
Miocene age. This usage differs from that of Dall,1 who appears to
have regarded the Chipola marl and the Alum Bluff as distinct for-
mations. The Alum Bluff formation includes two different, though
closely related, members which have been known respectively as the
Chipola marl and the Oak Grove sands. To these is added a third
member, recently discovered by Vaughan2 in west Florida, and called
the Shoal River marl member, from the stream where it is best
exposed. The Chipola marl member and. the sands of the type locality
at Alum Bluff were first described by Langdon, who referred them to
the Miocene.3
The type locality of the Chipola4 marl member is at McClelland's
farm, near Bailey's Ferry, on the Chipola River, and the Alum Bluff
formation is named from a bluff on the Apalachicola River, where it was
first examined. The fullers earth deposits which represent the Alum
Bluff formation east of the Apalachicola River, have been mentioned
by a number of writers, but the first comprehensive description of

Dall, Wm. H., Cenozoic Geology Along the Apalachicola River; Geol. Soc.
Am. Bull., vol. v, 1893, p. 167.
SVaughan, T. Wayland. Unpublished notes.
Langdon, Daniel W., Jr. Some Florida Miocene; Am. Jour. Sci., 2nd ser.,
vol. xxxviii, 1889, p. 32.
'Dall, Win. H., Neocene of North America, U. S. Geol. Survey Bull No.
84, 1893, p. 122.







FLORIDA STATE GEOLOGICAL SURVEY.


them was given by Vaughan' in 1901. The Oak Grove sand member
was described by Dali2 in 1893.
Exposures of limestone on the Sopchoppy and Ocklocknee Rivers,
some five or six miles from the town of Sopchoppy, have been called
the "Sopchoppy limestone." This rock was first described by Dall
who assigned it to about the horizon of the Chipola marl member. In
this report it is tentatively included with the Alum Bluff formation.
Further investigation is needed to determine its exact stratigraphic
relations.
The limestones and marls on the Manatee River near Ellenton
were thought by Heilprin4 to belong to the Miocene, but are probably
somewhat older. They are here referred tentatively to the Oak
Grove sand member of the Alum Bluff formation, but this correla-
tion is subject to revision, if subsequent investigations should show
that the fauna is characteristic of some other horizon.
Stratigraphic Position:-The Alum Bluff formation is conformable
upon both the Chattahoochee and the Hawthorne formations. This is
inferred from the facts that no distinct evidence of a stratigraphic
break between the two groups has been noted, and their faunas are
closely related. At Alum Bluff, on the Apalachicola River, and Jack-
son's Bluff, on the Ocklocknee River, the marls of Miocene age rest
upon an eroded surface of the Alum Bluff formation, but farther west,
in Walton County, it is possible that they may be conformable.
Lithologic Character: The, Alum Bluff formation consists of
marl, sand and clay, which are sometimes fairly distinct, but more
often interbedded. Limestones also occur in the formation, but they
are not extensively developed and usually contain enough earthy ma-
terial mixed with the carbonate of lime to form marls. Shell marls
with a calcareous or sandy matrix are common and they often occur
interbedded with nearly pure sand. In general, the beds belonging to
this formation are light gray, but occasionally shades of green or yel-
low prevail.
At Alum Bluff, on the Apalachicola River, DalPl gives the follow-
ing section:

'Vaughan, T. Wayland. Fuller's earth; U. S. Geol. Survey, Mineral Re-
sources of the United States, 1901, pp. 921-934.
SDall, Win. H. Cenozoic Geology Along the Apalachicola River, Geol. Soc.
Am. Bull., vol. v, 1893, pp. 166-167.
Dall, Wm. H., Neocene of North America, U. S. Geol. Survey, Bull. No. 84,
1892, pp. 119-120.
Heilprin. Angelo. Explorations on the west coast of Florida. Wagner
Free Inst., Trans., vol. 1, p. 13.
'Dall, Win. H., Geol. Soc. Am.. vol. v, 1893, p. 137.