Suwannee limestone in Hernando and Pasco Countries, Florida ( FGS: Bulletin 54)

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Material Information

Title:
Suwannee limestone in Hernando and Pasco Countries, Florida ( FGS: Bulletin 54)
Added title page title:
Petrography of the Suwannee limestone
Physical Description:
71 p. in various pagings : ill., graphs, maps (1 fold. in pocket) ; 23 cm.
Language:
English
Creator:
Yon, J. William
Hendry, Charles W. ( joint author )
Randazzo, Anthony F
Publisher:
Florida Dept. of Natural Resources, Division of Interior Resources, Bureau of Geology
Place of Publication:
Tallahassee, Fla.
Publication Date:

Subjects

Subjects / Keywords:
Limestone -- Florida   ( lcsh )
Petrology -- Florida   ( lcsh )
Genre:
non-fiction   ( marcgt )

Notes

Bibliography:
Includes bibliographies.
General Note:
Bulletin - State of Florida Bureau of Geology ; 54
Statement of Responsibility:
by J. William Yon Jr. and Charles W. Henry, Jr. Petrography of the Suwannee limestone / by Anthony F. Randazzo.

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 - AAA2295
notis - AFC8317
alephbibnum - 001045437
oclc - 150495456
oclc - 01972408
System ID:
UF00000251:00001

Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Title Page
        Page i
        Page ii
    Letter of transmittal
        Page iii
        Page iv
    Part I: Suwannee limestone in Hernando and Pasco counties, Florida
        Page A-v
        Page A-vi
        Page A-vii
        Page A-viii
        Page A-ix
        Page A-x
        Page A-1
        Page A-2
        Page A-3
        Page A-4
        Page A-5
        Page A-6
        Page A-7
        Page A-8
        Page A-9
        Page A-10
        Page A-11
        Page A-12
        Page A-13
        Page A-14
        Page A-15
        Page A-16
        Page A-17
        Page A-18
        Page A-19
        Page A-20
        Page A-21
        Page A-22
        Page A-23
        Page A-24
        Page A-25
        Page A-26
        Page A-27
        Page A-28
        Page A-29
        Page A-30
        Page A-31
        Page A-32
        Page A-33
        Page A-34
        Page A-35
        Page A-36
        Page A-37
        Page A-38
        Page A-39
        Page A-40
        Page A-41
        Page A-42
    Part II: Petrography of the Suwannee limestone
        Page B-i
        Page B-ii
        Page B-iii
        Page B-iv
        Page B-v
        Page B-vi
        Page B-1
        Page B-2
        Page B-3
        Page B-4
        Page B-5
        Page B-6
        Page B-7
        Page B-8
        Page B-9
        Page B-10
        Page B-11
        Page B-12
        Page B-13
        Page B-14
        Page B-15
    Back Cover
        Back Cover 1
        Back Cover 2
Full Text







d I 1Hd Randlph Hodges, Executiwe Director


DIVISION OF INTERiOR RESOURCES-
S. obert .; Vernron, Director


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


BULLETIN NO. 54



PART I
SUWANNEE LIMESTONE IN HERNANDO
PASCO COUNTIES, FLORIDA

SBy .
S; William Yon, Jr. and Charles W..Hendry, Jr.




PART II


AND."
i, -


TROGRAPHY OF THE SUWANNEE LIMESTONE

By
Anthony F. Randazzo

.t. .. .


Prepared by the . ". "
FLOOR I DA DEPARTMENT OF NATURAL RESOURCES
DIVISION OF INTERIOR:RESOURCES.
BUREAU OF .GEOLOGY.


TALLAHASSEE, FLORIDA
1972
... ". .. ,. .N.. .o 7 : i

g A.V''." :!.::.':':.: ''." " "'9 / -: : " ,i i, .; .. 7







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


DIVISION OF INTERIOR RESOURCES
Robert 0. Vernon, Director


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


BULLETIN NO. 54




PART I
SUWANNEE LIMESTONE IN HERNANDO AND
PASCO COUNTIES, FLORIDA


By
J. William Yon, Jr. and Charles W. Hendry, Jr.





PART II
PETROGRAPHY OF THE SUWANNEE LIMESTONE

By
Anthony F. Randazzo


Prepared by the
FLORIDA DEPARTMENT OF NATURAL RESOURCES
DIVISION OF INTERIOR RESOURCES
BUREAU OF GEOLOGY


TALLAHASSEE, FLORIDA
1972







I? 6 36.



DEPARTMENT
OF
NATURAL RESOURCES




REUBIN O'D. ASKEW
Governor


RICHARD (DICK) STONE
Secretary of State




THOMAS D. O'MALLEY
Treasurer




FLOYD T. CHRISTIAN
Commissioner of Education


ROBERT L. SHEVIN
Attorney General




FRED 0. DICKINSON, JR.
Comptroller




DOYLE CONNER
Commissioner of Agriculture


W. RANDOLPH HODGES
Executive Director







LETTER OF TRANSMITTAL


Bureau of Geology
Tallahassee
December 7, 1971


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

Dear Governor Askew:

The Department of Natural Resources, Bureau of Geology, is publishing
Bulletin No. 54. Part I is entitled "Suwannee Limestone in Hernando and
Pasco Counties, Florida" by J. W. Yon, Jr. and C.W. Hendry, Jr., Bureau
geologists, and Part II is entitled "Petrography of the Suwannee Lime-
stone" by A. F. Randazzo, Professor, Department of Geology, University
of Florida.

The Suwannee Limestone, a major component of the geology of the area,
is suitable for use in many manufacturing processes. In achieving the
orderly development of our land resources it is necessary to have a
knowledge of the occurrence, quantity and quality of the mineral re-
sources.

The data presented herein will assist the land-use planners and the mineral
industry in providing for full development of Hernando and Pasco
counties.

Respectfully yours,



Charles W. Hendry, Chief
Bureau of Geology



















































Completed manuscript received
December 7, 1971
Printed for the Florida Department of Natural Resources
Division of Interior Resources
Bureau of Geology
by News-Journal Corporation
Daytona Beach, Florida


Tallahassee
1972




iv







PART I
BULLETIN NO. 54













SUWANNEE LIMESTONE IN HERNANDO
AND PASCO COUNTIES, FLORIDA



By

J. William Yon, Jr.

and


Charles W. Hendry, Jr.















Tallahassee, Florida
1972








CONTENTS




Acknow ledgem ents ....................................... ........... ix
Previous Investigations ................................................. x
Introduction ............................. .................... ......... 1
Purpose and Scope ................................................... 1
Location of Area ...................................................... 1
Maps ...................... : ..................................... ... 2
Transportation ......................................................... 2
W ell and Outcrop Numbering System ................................. 2
Analytical Procedures ............. .................................... 5
Stratigraphy .................................... ........... .......... .. 8
Oligocene Series ............................................. 8
Suwannee Limestone ................................................. 8
Historical ......................................................... 8
Present Usage ................................................... 11
Lithology .......................................... .............. 12
Thickness .............................. ............ ............. 17
Geologic Sections ................................................ 19
Stratigraphic Relationships ....................................... 29
Paleontology ..................................................... 32
Structure ............................................................. 36
General Summary of Depositional History ................................. 37

Econom ic G eology ..................................................... 38
Bibliography .......................................................... 41


















vii








ILLUSTRATIONS


Figure

1 Location of Hernando and Pasco counties ............................ 2
2 Index to Topographic Maps of Hernando and Pasco counties ............. 3
3 W ell and outcrop numbering system ................................. 4
4 Location of well, outcrops, quarries, and lines of section
in Hernando and Pasco counties ....................................... 8
5 Contours showing approximate altitude of the top of the
Suwannee Limestone in Hernando and Pasco counties ................. 12
6 Detailed contours showing approximate altitude of the top
of the Suwannee Limestone in northern Hernando County .............. 13
7 Stratigraphic Cross Sections along lines A-A', B-B',
C-C', and D -D .......................................... In pocket
8 Rock Surfaces of post-Suwannee Limestone and Suwannee
Limestone from Camp Concrete and Rock Company Quarry,
Hernando County, Florida and McLeod Quarry, Pasco
C county, Florida ................................................... 14
9 View showing bedding and rubbly nature of Suwannee Limestone ........ 16
10 Graphs showing insoluble residue of quarry samples from
H ernando County .................................................. 18
11 Boulders of brecciatedd limestone from near contact of
post-Suwannee Limestone and Suwannee Limestone at Camp
Concrete and Rock Company Quarry, Hernando County ................. 21
12 Contact of post-Suwannee limestone and Suwannee Limestone
at Brooksville Rock Company Quarry, Hernando County .................. 31
13 Filled sinkhole developed in Suwannee Limestone. Also
note the bedded nature of limestone to right of sink ................... 32
14 Map of Florida showing location of Ocala uplift in a portion
of Florida and related faulting (Modified after Vernon, 1951) ............ 37
15 Camp Concrete and Rock Company Quarry, showing transportation
of rock to plant crusher .............................. ........... 39
16 Hatchered area indicates distribution of potential limestone
aggregate in Hernando and Pasco counties ............................ 39




TABLES

1 Geologic data from selected wells in Hernando, Hillsborough,
Pasco, Pinellas and Sumter counties ...................................... 6
2 Wells in Hernando and Pasco counties which contain Crystalline Limestone .... 15







ACKNOWLEDGEMENTS


The writers express their thanks to the staff of the Bureau of
Geology for their help in preparing maps, illustrations, typing, proofing,
and editing the manuscript and to the geologists for their suggestions and
discussions during preparation of this report.
Appreciation is expressed to Anthony Randazzo (University of Florida)
for reading the manuscript and making useful comments.
Gratitude is expressed to Muriel Hunter and Joseph Banks (Coastal
Petroleum Company) for giving freely of their information on the fossils
of the area and for accompanying the writers to the field on several
occasions.
The Brooksville Rock Company, the Camp Concrete and Rock Company,
and the McDonald Corporation were most cooperative in allowing the
writers access to their quarries.
The writers are grateful to Robert 0. Vernon, Chief of the Bureau of
Geology, for his helpful suggestions and efforts in making this study
possible.







PREVIOUS INVESTIGATIONS


In many of the reports on the geology of Florida, reference is made
to Hernando and Pasco counties. However, only those publications which
present more than a cursory report of the geology of the area are
mentioned below.
Mossom (1925, 1926), Cooke and Mossom (1929) and Cooke (1945)
discussed the general geology of the area. Mansfield (1937), described
the mollusks collected from quarries and outcrops in the area of study.
Carr and Alverson (1959), in their West-Central Florida study, discussed
the middle Tertiary rocks in Pasco County. Ketner and McGreevy (1959)
discussed the Cenzoic rocks occurring in the hard-rock phosphate belt
along the eastern edge of Hernando County. Wetterhall (1964), briefly
discussed the geology in Hernando and Pasco counties: Shannon (1967),
in his study of the foraminiferal faunas of the Tampa and Suwannee
limestones at or near the contact of the two formations, discussed two
localities in Hernando County.












SUWANNEE LIMESTONE IN HERNANDO
AND PASCO COUNTIES, FLORIDA


By
J. William Yon, Jr. and Charles W. Hendry, Jr.




INTRODUCTION

PURPOSE AND SCOPE OF STUDY


The competition between the mineral and agricultural industries for
the use of land, as well as the overshadowing demands of urban sprawl
for land, make it imperative that more aspects of the natural resources
be available for efficient land use planning. One important aspect of the
natural resources in any area is the geology. Limestone, a major compo-
nent of the geology, occurs in abundance at or near the surface in
Hernando and Pasco counties. Several principal uses of this rock are in
road building, agriculture, as an aggregate and in the manufacture of
cement. The purpose of this report was to provide information on the
distribution and character of the Suwannee Limestone in Hernando and
Pasco counties. The study was started in 1969 and has been conducted
intermittently since that time. Data on the geology were collected through
examination of the quarries in the two counties and surrounding area
and through the study of rock cuttings from numerous wells in Hernando,
Hillsborough, Pasco, Pinellas, and Sumter counties.

LOCATION OF AREA

The area of study encompasses Hernando and Pasco counties which
are located along the western side of the central Peninsula, as shown in
figure 1. The area is bounded on the north by Citrus County, on the east
by Sumter and Polk counties, the Gulf of Mexico on the west, and Pinellas
and Hillsborough counties on the south.






BUREAU OF GEOLOGY


+ R IT E + RA IS E + R 19 + R 20 E + R 21 E + R 22 E +


Figure 1. Location of Hernando and Pasco counties.


MAPS

All of Hernando and Pasco counties are covered by U.S. Geological
Survey and U.S. Army Corps of Engineers topographic maps in the 7%
minutes series see (figure 2) and by Florida Department of Transportation
general highway maps. The base map used in this report was made from
a U.S. Geological Survey base map.

TRANSPORTATION

Hernando and Pasco counties are served by the Seaboard Coast Line
Railroad.
The four major U.S. Highways that traverse Hernando County are
Interstate 75, U.S. Highways 19, 41 and 98. Three of these, Interstate 75,
U.S. Highways 19 and 41, traverse Pasco County.
Numerous state highways cover the area, generally radiating from the
county seats. In addition there are abundant secondary paved roads and
graded roads that permit access to almost every portion of the two
counties.


WELL AND OUTCROP NUMBERING SYSTEM

The well and outcrop numbering system used in this report is based on






BULLETIN NO. 54


location of the well or outcrop and uses the rectangular system of section,
township and range for identification. The well or outcrop number consists
of six parts: W for well or L for outcrop, county abbreviation, the quarter/
quarter location within the section, the section, township, and range.
The State of Florida is divided into large squares which measure six
miles on each side. These large squares are consecutively numbered both
north or south and east or west from a marker located in Tallahassee.
The north or south measurements are called townships and the east or
west measurements are called ranges. For example, a location designated
Township 22 South (T22S), Range 20 East (R20E) is 22 large squares south
and 20 large squares east of the Tallahassee marker. In locality and well
numbers the T and R are left off, as 22S and 20E.
To further identify a location the large squares (six miles on each side)
are divided into 36 equal squares called sections. The sections are further
divided into quarters with the quarters labeled "a" through "d". In turn,
each of these quarters may be divided into quarters with these quarter/
quarter squares labeled "a" through "d" (see figure 3).
The breakdown of the locality designated LHr22S-19E-8ac would be:


R I5E + R 16 E I R I7 E + R 18 E + RIS E + R 20E + R 21E +-

Figure 2. Index to Topographic Maps of Hernando and Pasco counties.








4 BUREAU OF GEOLOGY







-~ cJ j r')









-.0.


az


Ir ooEicl l
re) _ _ _

C:,













0








4 -



1-
sir- + z" +I


Co ,1
cr-sgc1









BULLETIN NO. 54


L designates an outcrop as opposed to a well, Hr indicates Hernando
County, 22S-19E means 22 large squares south and 19 large squares east
of the Tallahassee marker, 8 designates section number, and ac then
places the outcrop in the northwest quarter of the southwest quarter of
the section (fig. 3).
The abbreviation used for counties in this report are Ci for Citrus, Hr
for Hernando, and Ps for Pasco, Po for Polk, and Sm for Sumter. For
example, the well numbered WHr-22S-20E-23 aa is located in the north-
west quarter of the northwest quarter of section 22 in Township 22
South, Range 20 East.

ANALYTICAL PROCEDURES

Sixty-one water wells, one core hole, 12 quarries and three outcrops
were selected for the study. Their locations are shown in figure 4 and
geologic details of the wells are listed in Table 1.
Cuttings from the water wells, cores, outcrops and quarry samples
were examined under a binocular microscope. Each sample was examined
for lithology, color, crystallinity, other minerals present, cement, degree
of cementation, porosity, and fossils present.
As this study was primarily a lithologic evaluation no detailed
paleontological work was done. However, fossils described by other
workers as diagnostic were identified during the binocular examination
of all the above samples. Mention of these along with some of the
described macrofossils will appear later in the text. Petrographic
examination and comments by Randazzo of samples collected from the
quarry operated by Camp Concrete and Rock Company of Brooksville is
included as Part II.
Secondary recrystallization frequently obliterates basic lithologic
characteristics which are used for correlation and age determination.
Minor insoluble constituents deposited contemporaneously with the
basic carbonate are sometimes useful for bed differentiation and
correlation. For. this reason minor lithologic differences were determined
by using the insoluble residues. Fifty-gram portions were used from
samples collected from four quarries in Hernando County. These samples
were digested in dilute hydrochloric acid. The amount and character of
the insoluble residue were examined. The results of these data will be
discussed in the text to follow.







6 BUREAU OF GEOLOGY

Table 1. Geologic Data from selected wells in Hernando, Hillsborough, Pasco,
Pinellas, and Sumter Counties

Depth in feet to Top of Geologic Formation




a ->= a & c o .-



HERNANDO COUNTY
6234 WHr-21S-18E-15ab 121.0 0.0 0.0 10.0 60.0
274 WHr-21S-19E-36ca 261.0 0.0 76.0 100.0 198.0
7766 WHr-22S-17E-3cc 8.0 0.0 20.0 45.0
7764 WHr-22S-17E-5aa 8.0 0.0 8.0
7765 WHr-22S-17E-9aa 9.0 0.0 9.0
7439 WHr-22S-17E-28ca 7.0 0.0 15.0 30.0
7768 WHr-22S-18E-29cc 36.0 0.0 42.0 55.0
2876 WHr-22S-19E-6ad 55.0 0.0 25.0
4697 WHr-22S-19E-11dc 93.0 0.0 18.0 25.0 95.0
10306 WHr-22S-19E-21dd 129.0 0.0 5.0 100.0
5608 WHr-22S-19E-34ba 144.0 0.0 70.0 144.0
4205 WHr-22S-20E-19bc 128.0 0.0 5.0 93.0
7737 WHr-22S-21E-8dd 55.0 0.0 30.0
5759 WHr-22S-21E-15ac 57.0 0.0 21.0
10464 WHr-22S-21E-32cc 79.0 0.0 70.0 130.0
7763 WHr-23S-16E-25bd 8.0 0.0 8.0 120.0
7767 WHr-23S-17E-2bb 23.0 0.0 28.0 46.0
10356 WHr-23S-17E-28 34.0 0.0 50.0 120.0
10354 WHr-23S-18E-21dc 62.0 10.0 140.0
707 WHr-23S-19E-18cc 68.0 25.0 105.0
8357 WHr-23S-19E-35db 98.0 0.0 15.0 -
5694 WHr-23S-20E-3aa 118.0 0.0 30.0 130.0
1442 WHr-23S-20E-12bb 160.0 0.0 40.0 90.0 170.0
6556 WHr-23S-20E-17dd 107.0 0.0 30.0 150.0
8426 WHr-23S-20E-32ad 139.0 0.0 35.0 40.0 200.0
PASCO COUNTY
10298 WPs-23S-21E-19ca 105.0 0.0 70.0 -
6470 WPs-23S-21E-22cd 81.0 0.0 60.0 70.0
7801 WPs-23S-22E-26ac 82.0 0.0 15.0
3357 WPs-24S-16E-27cc 8.0 0.0 4.0 10.0 -
5271 WPs-24S-16E-34dc 8.0 0.0 15.0 -
7463 WPs-24S-18E-1 66.0 0.0 25.0 30.0 -
8318 WPs-24S-18E-35cb 89.0 0.0 60.0 240.0
2199 WPs-24S-20E-llbd 251.0 0.0 90.0 130.0 -
8507 WPs-24S-20E-35bc 192.0 0.0 120.0 230.0
8840 WPs-24S-21E-15ba 76.0 0.0 60.0 85.0 135.0
2707 WPs-24S-21E-28bb 114.0 0.0 70.0 170.0
6504 WPs-24S-21E-33bd 137.0 0.0 46.0 -
3805 WPs-25S-16E-4ad 48.0 0.0 42.0 120.0 -
7464 WPs-25S-17E-5bc 31.0 0.0 25.0 -
7405 WPs-25S-17E-12ad 55.0 0.0 47.0 -
7403 WPs-25S-17E-29ad 36.0 0.0 40.0 60.0 -
7465 WPs-25S-19E-7bd 82.0 0.0 30.0 40.0 -
7419 WPs-25S-19E-12bd 85.0 0.0 70.0 -
5865 WPs-25S-20E-lldd 121.0 0.0 50.0 140.0






BULLETIN NO. 54


Table 1. Continued


0 >
C *) -Q -) C


cn 0 0 4

7466 WPs-25S-20E-26ba 125.0 0.0 50.0 80.0 -
5282 WPs-25S-21E-8db 127.0 0.0 40.0 1:30.0
2160 WPs-25S-21E-22db 226.0 0.0 136.0 -
5350 WPs-25S-22E-28dc 89.0 0.0 19.0 35.0
10471 WPs-26S-15E-36dd 16.0 0.0 :38.0 135.0 -
1836 WPs-26S-16E-4ad :38.0 0.0 65.0 85.0 -
7411 WPs-26S-16E-24bc :36.0 0.0 20.0 95.0 -
7418 WPs-26S-18E-28db 60.0 0.0 55.0 80.0 295.0
6169 WPs-26S-18E-36aa 73.0 0.0 42.0 -
:34:34 WPs-26S-20E-35dd 67.0 0.0 45.0 175.0
:3284 WPs-26S-21E-3db 82.0 0.0 60.0 65.0 160.0
2972 WPs-26S-21E-Ilba 105.0 0.0 60.0 -
662 WPs-26S-21E-13aa 81.0 55.0 175.0
:3512 WPs-26S-21E-27ba 70.0 0.0 20.0 60.0
SUMTER COUNTY
7802 WSm-23S-23E-31ca 95.0 0.0 30.0
5054 WSm-24S-23E-31bb 97.0 0.0 7.0
PINELLAS COUNTY
2526 WPi-27S-16E-11 23.0 0.0 55.0 100.0 350.0
HILLSBOROUGH COUNTY
70:32 WHI-27S-22E-6db 84.0 0.0 30.0 170.0







8 BUREAU OF GEOLOGY


STRATIGRAPHY


OLIGOCENE SERIES

SUWANNEE LIMESTONE

HISTORICAL


Cooke and Mansfield (1936, p. 71) erected the name Suwannee
Limestone and made the following statement:
"The name 'Suwannee limestone' is proposed for yellowish limestone
typically exposed along the Suwannee River in Florida, from Ellaville,
where it unconformably overlies white limestone containing Vicksburg


2 1 0 2 4 6MLIt,
EXPLANATION A o scole
o Well location
Quorry
+ Outcrop
A -A Line of croSS section


LOCATION
H GwMeo-osc.
Counli


Figure 4. Location of wells, outcrops, quarries, and lines of section in Hernando
and Pasco counties.






BULLETIN NO. 54


(Oligocene),fossils, almost to White Springs near which it lies uncon-
formably below the Miocene Hawthorn formation. Another large area
of Suwannee limestone, centering near Brooksville, Hernando County,
lies between the Eocene Ocala limestone (on the north) and the Miocene
Tampa limestone (on the south).
"Most writers have regarded the Suwannee limestone as part of the
Tampa limestone. The writers think it is of late Vicksburg age, because
it contains the echinoid Rhyncholampas gouldii (Bouve), which is
known elsewhere only in the late Vicksburg Flint River formation, and
several species of Flint River mollusks. The presence of a species of the
foraminiferal genus Coskinolina (C. cookei Moberg) suggests an age older
than Miocene. The Suwannee limestone is correlated tentatively with the
Flint River formation of Georgia and with the Chickasawhay marl member
of the Byram marl of Mississippi, which occupies the uppermost known
horizon of the Vicksburg group."
Dall (1892, p. 121) did not consider Oligocene beds to be present in
Florida and placed the limestones cropping out along the Suwannee River
at Ellaville in his Tampa beds of Miocene age.
In their report of 1909 (p. 73-74) Matson and Clapp reported that
specimens of the echinoid Cassidulus were obtained from cherty rocks
that probably came from the channel of the Suwannee River at White
Springs, Hamilton County. They also reported finding Cassidulus in
cherty rocks at Croom, Hernando County. The close proximity of the
Cassidulus bearing rocks to the Hawthorn Formation at White Springs led
Matson and Clapp (1909, p. 73-74) to believe the Cassidulus zone oc-
curred near the top of the Hawthorn and was of Miocene age.
Mossom (1925, p. 78-79) found Cassidulus gouldii (Bouve) in the
Florida Rock Products pit just west of Brooksville, and he noted
similarities between the faunal assemblage in the rocks at Brooksville
and those in deposits he mapped as Glendon age in Hamilton and Suwannee
counties. However, he (Mossom 1925, p. 78-79) felt the deposits at
Brooksville were correlative with the Miocene age Tampa Formation
occurring in the Tampa Bay Area and consequently placed them in the
Tampa.
Later Mossom (1926, p. 182-183) correlated the deposits he mapped
as Tampa in Hernando and Pasco counties and on the north side of Hills-
borough Bay with similar deposits found in other parts of northern
Florida, particularly those along the Suwannee River from Ellaville to
White Springs. He placed all of them in the Miocene age Tampa Forma-
tion.
Cooke and Mossom (1929, p. 72-92) also mapped as Tampa the upper
portion of the deposits described by Mossom in 1926. However, as shown
in the following section they (Cooke and Mossom, 1929, p. 72) considered
the lower portion of the section exposed at Ellaville to be Glendon age.






BUREAU OF GEOLOGY


This section was measured by Cooke and Mossom in 1913 at the Seaboard
Coast Line Railroad bridge below the confluence of the Withalacoochee
River with the Suwannee River.

SECTION ON EAST BANK SUWANNEE RIVER OPPOSITE
ELLAVILLE

Pleistocene: Feet
5. Upper part concealed; lower part is agillaceous yellow
sand containing small pebbles; the top is level with
rail at bridge ................. ................... 16.5

Unconformity: Feet
Miocene; Tampa Limestone:
4. Hard, cream-colored to yellow limestone resembling
bed 3 but very massive and without bedding planes;
Cassidulus gouldii Bouve very abundant .......... 10.5
3. Hard, chalky-white to pink, compact, crystalline
limestone; lower 2 feet appear to be brecciated;
upper part is thin-bedded ....................... 4.0
Oligocene; Glendon limestone:
2. Soft, white, marly limestone, indurated in places;
contains a few Bryozoa and many fragments of
Clypeaster rogersi Morton? ...................... 2.0
1. White or creamy yellow compact limestone loaded
with casts of mollusks (Station 6824); honey-
combed by solution; extends to water level ...... 5.5

Cooke and Mossom (1929, p. 78-92) further stated that the
fossils in bed 1 of the preceding section is of Vicksburg age and cor-
related this bed with the Glendon limestone.
Mansfield (1937) described the mollusks from the Suwannee Lime-
stone but suggested no change in terminology or age for the forma-
tion as he and Cooke (1936, p. 71) originally described it.
In 1944, MacNeil (p. 1317) reiterated the Oligocene age assign-
ment to the Ellaville limestone beds; however, he reported that the
gastropod Turritella martinensis occurred in the lower 7.5 feet and con-
sidered this lower unit to be lower Oligocene in age.
Cooke (1945, p. 86) suggested no change in the Suwannee deposits
as previously mapped. However, he (Cooke, 1945, p. 85-86) did
place the two lower beds of the section at Ellaville in the Byram Lime-
stone which he and Mossom (1929, p. 72) had previously mapped as
Glendon.
According to MacNeil (1946, p. 48-49; 1947) not only did the
base of the Oligocene exposed at Ellaville contain Turritella mar-






BULLETIN NO. 54


tinensis but this fossil also occurred in a quarry near Martin Station
[Martin Station is in Marion County, although MacNeil placed it in
Hernando County] and in a quarry at Crystal River, Citrus County. As
Turritella martinensis in eastern Mississippi occurs in the Mint Spring
member of the Forest Hill Sand of lower Oligocene age, MacNeil (1946,
p. 48-49; 1947) redefined the Suwannee limestone to include the
Byram equivalent in western Florida and considered the zone of
northern and peninsula Florida to be a basal member.
In discussing the Suwannee Limestone exposed at the Crystal River
Rock Company Quarry at Crystal River, Florida, Vernon (1951, p. 175)
stated: "Since the lower section of the interval assigned to the Su-
wannee limestone (beds 7 to 12) contains molds of mollusks found
elsewhere in the Byram formation, the Forest Hill sand and the
Suwannee limestone, there is a possibility that the section at Crystal
River Rock Company quarry represents a time interval of the entire
Oligocene epoch, and in this respect corresponds to the usage of the
term, Suwannee limestone, in Holmes and Washington counties,
Florida (Vernon, 1942). Since these basal beds, numbers 7 through 12,
have been identified in Citrus County only at locality C-64 and pos-
sibly at C-108, pages 170-171, it was impossible to map those beds
separately and they have been included with the Suwannee limestone.
As used in this report the Suwannee limestone includes all beds of
Oligocene age in Citrus and Levy counties. The upper part of the for-
mation is considered to be the equivalent of the lower Chickasawhay
marl of eastern Mississippi, and the lower part possibly the equivalent
of the Byram formation and Marianna limestone of western Florida."

PRESENT USAGE
The Suwannee Limestone as used in this report consists of all beds
in Hernando and Pasco counties identified as Oligocene in age that
overlie the Crystal River Formation and underlie post-Oligocene deposits.
Distribution: Most of Hernando and Pasco counties are underlain by
the Suwannee Limestone. The exceptions are a triangularly shaped
area in the northwestern portion and a strip bordering the Withlacoochee
River on the eastern side of Hernando County and a triangular area in
the northeastern portion of Pasco County (see figure 5). In the areas
where the Suwannee is missing the Crystal River Formation lies below
post-Oligocene clastics.
The Suwannee lies very near the surface and in places crops out
along the coast from Hudson, Pasco County to Bayport, Hernando
County.
The altitude and distribution of the Suwannee Limestone in the
central and eastern portions of Hernando County (fig. 5) were deter-
mined using scattered well data and outcrop data. As depicted on the






BUREAU OF GEOLOGY


contour maps of the top of the Suwannee (fig. 5, figure 6) and in
the stratigraphic cross sections (figure 7), the top of the Suwannee
is very irregular.
The Suwannee Limestone in Pasco County, for the most part, occurs
in the subsurface. The possible exception to this is the northwestern
and eastern portions of Pasco County where it is reported (Carr and
Alverson, 1959) to crop out. The authors were unable to verify this.
LITHOLOGY
The Suwannee Limestone in the area of study is a marine, bio-
clastic limestone which can be described as follows:
1. Partially recrystallized limestone (calcarenite), very pale
orange, finely crystalline in part, firmly to. weakly cemented
with calcite, sandy (very fine to fine), may contain small
amounts of silt and clay, moderate to high intergranular
and macromoldic porosity, generally very microfossiliferous,
commonly containing Coskinolina floridana, Discorinopsis
gunteri, Rotalia mexicana, and molds of mollusks.
2. Crystalline limstone (calcarenite), very pale orange, very
finely crystalline, firmly cemented with calcite (hard), sandy
(very fine to fine), slightly silty and clayey, low to moderate


Figure 5. Contours showing approximate altitude of the top of the Suwannee
Limestone in Hernando and Pasco counties.






BULLETIN NO. 54


moldic porosity, generally very microfossiliferous, commonly
containing Coskinolina floridana, Discorinopsis gunteri,
Rotalia mexicana and molds of mollusks.
3. Crystalline limestone (calcarenite), very pale orange, very
finely crystalline, very firmly cemented with calcite (hard),
sandy (very fine to fine), more silty and clayey than previous-
ly described No. 2, low to moderate moldic porosity, gener-
ally very microfossiliferous, contains miliolids, Rotalia
mexicana, and molds of mollusks common.
The crystalline limestones (calcarenite), pictured in figure 8
and described as units two and three under Lithology, seem to be re-
lated to the subsurface high that trends northwest and southeast
through Hernando and Pasco Counties (see figures 5, 6, and 7). This
conclusion is supported by the absence of the crystalline limestone
(units two and three under Lithology) in the subsurface low areas
on the western side of Hernando County where only partially recrystal-
lized limestone occurs. The rock in the upper part of the Suwannee
RI1E RI9E R20E

491 .= == 41






















EXPLANATION
+ Outcrop o-50 Line, in feet, referred to
o Well or Core Hole Meon Sea Level
0 Quarry CstlirFma
Contour Interval 25 Feet g ** Crystal Rivr Formation
.- Probable Fault
Figure 6. Detailed contours showing approximate altitude of the top of the
Suwannee Limestone in northern Hernando County.






BUREAU OF GEOLOGY


W .,
I'.

I ~ *~e~ ~'


X' 0


,.o i 31:


IV
it
7/- - 4;.*


T ..T


Figure 8. A. Suwannee Limestone, from McLeod Quarry, Pasco County, show-
ing hard and soft beds.
B. Post Suwannee limestone, from Camp Concrete and Rock Com-
pany Quarry, Hernando County, showing dark angular fragments
in a calcilutite matrix.
C-F. Crystalline Suwannee Limestone, from Camp Concrete and Rock
Company Quarry, Hernando County. D-F show cross sections
of mollusks.


'. *^ V ..
-N i




/ILI


-L .;






BULLETIN NO. 54


section appears to contain finer grained carbonate particles, but
not enough to be called a calcilutite and contains more insoluble
material. In describing the lithology of the Suwannee deposits from
water-well cuttings the writers made particular note of the wells
which contained crystalline limestone (see Table 2).
Another observation made from studying the well cuttings that
contain crystalline limestone was the absence of the soft carbonate
material that was seen interbedded with the calcarenites in the
quarry sections. It may be that the interbedded softer material was
washed away during the drilling of the wells.
The Suwannee Limestone seen in the quarries around Brooksville
and at McLeod quarry in Pasco County has alternating hard and



Table 2. Wells in Hernando and Pasco Counties which contain Crystalline Limestone


C-
C-









HERNANDO COUNTY
274 WHr-21S-19E-36ca 261.0 76.0 100.0 21.0
4697 WHr-22S-19E-lldc 93.0 18.0 25.0 10.0
10306 WHr-22S-19E-2ldd 129.0 5.0 20.0
5608 WHr-22S-19E-34ba 144.0 70.0 15.0
4205 WHr-22S-20E-19bc 128.0 25.0 20.0
8357 WHr-23S-19E-35db 98.0 15.0 20.0
5694 WHr-23S-20E-3aa 118.0 30.0 20.0
1442 WHr-23S-20E-12bb 160.0 40.0 90.0 30.0
6556 WHr-23S-20E-17dd 107.0 30.0 35.0
8426 WHr-23S-20E-32ad 139.0 35.0 40.0 :30.0
PASCO COUNTY
10298 WPs-23S-21E-19ca 105.0 70.0 unknown
6470 WPs-23S-21E-22cd 81.0 60.0 5.0
8318 WPs-24S-18E-35cb 89.0 60.0 20.0
2199 WPs-24S-20E-11bd 251.0 130.0 50.0
8507 WPs-24S-20E-35bc 192.0 120.0 10.0
8840 WPs-24S-21E-15ba 76.0 60.0 85.0 40.0
7405 WPs-25S-17E-12ab 55.0 47.0 52.0 9.0
7403 WPs-25S-17E-29ad :36.0 40.0 43.0 15.0
5865 WPs-25S-20E-11dd 121.0 47.0 50.0 10.0
5282 WPs-25S-21E-8db 127.0 40.0 20.0
2160 WPs-25S-21E-22db 226.0 136.0 14.0






BUREAU OF GEOLOGY


soft beds of varying thicknesses. During weathering the softer ma-
terial which has some characteristics of a calcilutite erodes away
and the harder beds stand out. Differential compaction and subse-
quent slump of the formation disrupts the harder beds of rock and
gives them the appearance of being rubbly (figure 9). Generally,
throughout the quarries thin seams and beds of clay occur in the
limestone. In most of the quarries chert nodules and thin beds of
chert are associated with the limestone. In the Lansing Quarry,
Hernando County, a massive chert bed up to one foot thick occurs
near the base of the Suwannee. As observed by the writers and re-
ported by Ketner and McGreevy (1959, p. 57) a rubble of silicified
Suwannee Limestone overlies the Crystal River Formation in the hard-
rock phosphate belt along the eastern side of Hernando County.
According to Ketner and McGreevy (1959, p. 58) three samples of
Suwannee Limestone collected from the McDonald Limestone quarry
(sec. 19, T22S, R20E-Hernando County) and a hard-rock phosphate pit
(seo. 18, T22S, R21E-Hernando County) contain less than 0.2 percent
P205 and less than 0.1 percent A1203. The writers found all quarry samples
and well cuttings from the Suwannee Limestone to be phosphatic, how-
ever, no attempt was made to determine the percent of phosphate in
the samples.
Chemical analyses of samples from four quarries in the Brooks-
ville area indicate the Suwannee Limestone contains from 92.41 per-


Figure 9. View showing bedding and rubbly nature of Suwannee Limestone.






BULLETIN NO. 54


cent to 99.56 percent calcium carbonate. The insoluble residue
portion of these samples consisted of quartz sand, silt and clay along
with a trace of heavy minerals. The quartz sand is very fine to fine
grained, predominantly subangular with some subrounded grains.
Figure 10 graphically depicts the relative quantities of insoluble
residue (sand, clay and silt) found in samples obtained from the four
quarries in the Brooksville area. Note that the amount of insoluble
material decreases downward in the Suwannee Limestone. There
are two zones where the amount of insoluble material is the greatest,
one 0-10 feet below the top of the Suwannee and the other 29-43
feet below the top. In the Lansing Quarry the amount of insoluble
residue drops significantly from 42 feet below the top of the Su-
wannee down to the contact with the Crystal River Formation. In
wells WPs25S-19E-12bd and WPs24S-18E-1 in Pasco County peat is
incorporated in the limestone near the base of the formation. In
wells WPs26S-21E-13aa, WPs26S-18E-28db and WPs24S-18E-35cb, also
located in Pasco County, the base of the Suwannee sediments contains
dolomite as well as peat.

THICKNESS

The thickness of the Suwannee Limestone in portions of Hernando
County is variable because of the karst surface developed on its top.
The stratigraphic cross sections (fig. 7) give some idea as to the
thickness of the formation. A-A' indicates that the Suwannee Lime-
stone on the western side of Hernando County may be 12-15 feet
thick. It thickens to as much as 110 feet in the central portion and
thins again on the eastern side of Hernando County. Section B-B'
shows that the Suwannee varies from 0 to 95 feet in thickness. Sec-
tion D-D', a northwest-southeast cross section through Hernando and
Pasco counties, shows the Suwannee to be 160 feet thick near the Her-
nando-Pasco county line. Section C-C' through Pasco County shows
the Suwannee to thicken westward, and it may be up to 175 feet thick.
In well WPs26S-18E-28db near the boundary of Pasco-Hernando coun-
ties the Suwannee Limestone is 215 feet thick and probably approaches
the maximum thickness for the formation in the two counties.

Stratigraphic cross section A-A' and D-D' indicates that the crys-
talline limestone is thick in the upper and central portion of Her-
nando County but in section D-D' from Brooksville southward it begins
to thin appreciably.

The relationship of the thickness of the crystalline limestone portion
to the partially recrystallized limestone portion of the Suwannee






BUREAU OF GEOLOGY


eec
o~E
-e

Pc-
$


1~i


4






BULLETIN NO. 54


Limestone, as shown on the stratigraphic cross sections is based on
several factors:
1. Observation and examination of the rocks occurring in the
quarries.
2. Study of well cuttings.
3. Projections of the above observations into areas of no data
based on a combination of the two.

GEOLOGIC SECTIONS

The following geologic sections are those used in preparing the strati-
graphic cross sections and the contour maps used in this report:
Citrus County:
1. Locality LC20S-18E-36ca (Vernon, 1951, p. 170-180): In
a limestone pit 3.4 feet of crystalline limestone (calcaren-
ite) overlies the Crystal River Formation of Eocene age.
Hernando County:
1. Locality LHr22S-19E-8ac: The following description is of
samples taken from the north face of a quarry operated
by Camp Concrete and Rock Company located in the
NW1/4, SW1/4 sec. 8, T22S, R19E.

Depth in feet from
Sample No. Description top of Quarry Face

post Suwannee limestone
1 Partially recrystallized limestone (calcilutite), yellow- 0
ish gray, finely crystalline in part, firmly cemented
with calcite, earthy appearance, sandy (very fine to
fine), silty, clayey, manganese stained, contains
pockets of clay, moderate to low intergranular por-
osity, no fossils noted, trace of heavy minerals.
2 As above, but contains pockets filled with moderate- 4
yellowish brown chert. This rock has the appear-
ance of being brecciated.
3 As above, but contains pale yellowish brown pebbles 8
of crystalline dolomite, pockets of pale green clay
present.
4 Same as No. 1 and contains chert pockets, phos- 12
phatic and perhaps finer grained and harder.
Oligocene Series
Suwannee Limestone
5 Crystalline limestone (calcarenite), very pale orange 16
to pale yellowish brown, finely crystalline, very
firmly cemented with calcite (hard), sandy (very






BUREAU OF GEOLOGY


Depth in feet from
Sample No. Description top of Quarry Face
fine to fine), silty and clayey, low cavernous por-
osity, slightly microfossiliferous.
6 Partially recrystallized limestone (calcarenite), very 20
pale orange, finely crystalline in part, firmly cement-
ed with calcite, sandy (very fine to fine), silty and
clayey, low intergranular porosity, microfossils
noted in matrix, macromoldic.
7 As above. 24
8 As above. 28
9 Crystalline limestone (calcarenite) very pale orange, 32
very finely crystalline, very firmly cemented with
calcite (hard), contains slight amount of very fine to
fine sand, silty and clayey.
10 Crystalline limestone (calcarenite), very pale orange, 36
very finely crystalline, very firmly cemented with
calcite (hard), sandy (very fine to fine), silty and
clayey, low moldic and cavernous porosity, micro-
fossiliferous-Rotalia mexicana identified, macro-
moldic.
11 As above, but more macromoldic, thusly giving it 40
moderate moldic porosity, Turritella sp. identified.
12 Same as No. 10, but contains less macrofossils-Ro- 44
talia mexicana present.
13 Crystalline limestone (calcarenite), very pale orange, 48
very finely crystalline, cemented with calcite (hard),
sandy (very fine to fine), silty and clayey, moderate
to low moldic and cavernous porosity, slightly mac-
romoldic.
14 As above. 52
15 As above. 56
16 Partially recrystallized limestone (calcarenite), very 60
pale orange, very fine to finely crystalline in part,
cemented firmly with calcite (hard), contains slight
amount of very fine, angular sand, silty and clayey,
contains zones of yellowish brown chert, moderate
intergranular porosity, very microfossiliferous, also
macrofossiliferous.
17 Crystalline limestone (calcarenite), very pale orange, 64
very finely crystalline, cemented with calcite (hard),
contains small amount of very fine to fine sand, silty






BULLETIN NO. 54


Depth in feet from
Sample No. Description top of Quarry Face
and clayey, intergranular, cavernous and moldic
porosity, microfossiliferous.

The section exposed here shows a series of alternating hard with thinner
softer beds that have weathered to a very nodular appearing limestone.
Lenses, blebs and pockets of green clay occur in the limestone through-
out the quarry. Large boulders of brecciA'ed appearing rock occur on
the quarry floor (figure 11) which come from the post-Suwannee lime-
stone exposed at the top of the quarry face.

2. Locality LHr2lS-18E-23dd: The following description is
of samples taken from the north face of the quarry oper-
ated by Brooksville Rock Company located in the SE1/4
SE1/4 sec. 23, T21S, R18E.

post-Suwannee limestone
1 Partially recrystallized limestone (calcilutite), light 3.0
gray, finely crystalline in part, cemented with calcite
(hard), sandy (very fine to fine), silty, clayey, man-
ganese stained, moderate intergranular porosity,



4


















Figure 11. Boulders of brecciatedd limestone from near contact of post Suwannee
limestone and Suwannee Limestone at Camp Concrete and Rock Com-
pany Quarry, Hernando County.






BUREAU OF GEOLOGY


Depth in feet from
Sample No. Description top of Quarry Face

very rubbly appearance and contains pockets, blebs
and lenses of green clay.
2 As above, contains molds of gastropods. 6.0
3 As above, appears to be very silty. 10.5
Oligocene Series
Suwannee Limestone
4 Crystalline limestone (calcarenite), very pale orange 11.2
to pale yellowish brown, very-finely crystalline, ce-
mented with calcite (very hard), contains less sand,
silt and clay than above, low cavernous porosity,
microfossiliferous, but nondistinctive because of
recrystallization, macrofossiliferous-Rhiiyncholampas
gouldii identified. This sample has the appearance of
being brecciated, however, the smaller, very pale
orange angular fragments within the pale yellowish
brown matrix may be a product of recrystallization
rather than deposition. Sediments are more massive
than material above and forms a distinct ledge.
5 As above. 14.3
6 Crystalline limestone (calcarenite), very pale orange 17.6
to pale yellowish brown, finely crystalline, cemented
with calcite (hard), sandy (very fine to fine), silty
and clayey as above, low cavernous porosity, con-
tains scattered pockets of sand-size particles, intense
recrystallization makes identification of microfos-
sils impossible; limestone weathers to give the sedi-
ments a rubbly, nodular appearance.
7 As above, but predominantly very pale orange, ce- 23.0
mented firmly with calcite (hard), (if fossils present
recrystallization has destroyed them.)
8 Partially recrystallized limestone (calcarenite), very 37.0
pale orange, finely crystalline in part, cemented with
calcite (firm), sandy (very fine to fine), silty and
clayey, moderate to high intergranular porosity,
very microfossiliferous, abundant 'cones'- Coskino-
lina floridana identified, miliolids, macromoldic.
9 As above, but weakly to firmly cemented with cal- 41.0
cite, pale yellowish orange.
10 Same as No. 8, predominantly recrystallized but also 44.0
crystalline in part. Sorites sp. identified.
11 Partially recrystallized limestone (calcarenite), very 46.0






BULLETIN NO. 54


Depth in feet from
Sample No. Description top of Quarry Face
pale orange, manganese and iron stained, cemented
firmly with calcite, silty and clayey as above, mi-
crofossiliferous, 'cones' and miliolids.
12 Same as No. 8 49.0
13 Same as No. 10, perhaps more crystalline. 52.0
14 Same as No. 10. 54.5
15 Crystalline limestone (calcarenite), very pale or- 57.5
ange, very finely crystalline, cemented firmly with
calcite (hard), sandy (very fine to fine), silty and
clayey as above, moderate intergranular and moldic
porosity, microfossiliferous and macromoldic-Rhyn-
cholampus gouldii identified.
16 Crystalline limestone (calcarenite), grayish orange, 60.0
very finely crystalline, cemented with calcite (hard),
sandy (very fine to fine), silty and clayey as above,
low moldic and cavernous porosity, microfossilifer-
ous but fossils have been obscured by recrystalliza-
tion.
17 Partially recrystallized limestone (calcarenite), very 63.0
pale orange, finely crystalline in part, cemented with
calcite (firm), sandy (very fine to fine), silty and
clayey as above, high intergranular porosity, micro-
fossiliferous-Coskinolina floridana identified, mac-
romoldic.
18 Partially recrystallized limestone (calcarenite), very 67.5
pale orange, finely crystalline in part, weakly to
firmly cemented with calcite, sandy (very fine to
fine), silty and clayey, high intergranular porosity,
microfossiliferous-Coskinolina floridana and Discor-
inopsis gunteri identified, macromoldic.
19 As above. 72.5
The section exposed here shows a series of alternating hard and soft
rubbly beds of varying thickness. Some blebs and pockets of green
clay occur in the section.
3. Locality LHr21S-19E-17cd: In an abandoned quarry of
the Florida Rocks Products Company, on the east side of a
paved road, varying thicknesses of crystalline limestone
(calcarenite) are exposed. The Suwannee exposed here is
a series of hard and soft beds that have weathered to a
nodular appearing limestone.
4. Locality LHr21S-19E-22a: The following descriptions of
samples from the Lansing quarry were taken in a discon-






BUREAU OF GEOLOGY


Depth in feet from
Sample No. Description top of Quarry Face
tinuous section from the center and the northwest faces
of the most westerly pit as well as from the north face of
the central pit. The quarry is located in S1/2 NW1/4 sec.
22, T21S, R19E.
post-Suwannee limestone
1 Crystalline limestone (calcilutite), pale orange, very 0
finely crystalline, cemented with calcite (hard),
sandy (very fine to medium some coarse grains),
very silty and clayey, moderate intergranular poros-
ity, no fossils observed.
2 As above, contains fine to medium grained sand. 5
3 Partially recrystallized limestone (calcilutite), very 10
pale orange, finely crystalline in part to chalky,
very weakly to firmly cemented with calcite, sandy
(very fine to medium), clayey, silty, moderate inter-
granular porosity.
4 As above, perhaps less silty and clayey, some gray- 13
ish brown chert present.
5 As above, no chert present. 15

Oligocene Series
Suwannee Limestone

6 Crystalline limestone (calcarenite), very pale orange, 18
very fine to finely crystalline, cemented with cal-
cite (hard), sandy (very fine), silty and clayey, mod-
erate to low intergranular porosity, microfossilifer-
ous-Rotalia mexicana identified, macromoldic.
7 As above, crystalline limestone (calcarenite), very 23
pale orange, very finely crystalline, cemented
firmly with calcite (hard), sandy (very fine), silty
and clayey, moderate to low intergranular porosity,
microfossiliferous.
8 Crystalline limestone (calcarenite), very pale orange, 28
very fine to finely crystalline, very firmly cemented
with calcite (hard), sandy (very fine to fine), silty
and clayey, moderate intergranular porosity, micro-
fossiliferous-Sorites sp. and Rotalia mexicana identi-
fied, macromoldic-Kuphus incrassatus identified.
9 Crystalline limestone (calcarenite), very pale orange, 33
chalky to finely crystalline, soft to cemented hard
with calcite, very sandy (fine), silty and clayey, mod-






BULLETIN NO. 54


Depth in feet from
Sample No. Description top of Quarry Face
rate to high intergranular porosity, macrofossilif-
erous-Rhyncholampas gouldii present.
10 Same as sample No. 8. 42
11 Crystalline limestone (calcarenite), very pale orange, 47
soft to firmly cemented with calcite, sandy (very
fine to fine), silty and clayey, moderate to high inter-
granular porosity, microfossiliferous-Rotalia mexi-
cana identified.
12 Crystalline limestone (calcarenite), same as above. 62
13 Crystalline limestone (calcarenite), orange, very 65
finely crystalline, cemented with calcite (hard),
sandy (very fine to fine), silty and clayey, low inter-
granular porosity, microfossiliferous, macromoldic.
14 Partially recrystallized limestone (calcarenite), very 80
pale orange, finely crystalline in part, firmly ce-
mented with calcite, slightly sandy (very fine), silty
and clayey, high intergranular porosity, microfos-
siliferous-Coskinolina floridana and Discorinopsis
gunteri identified, macromoldic.
15 As above, but crystalline in part. 90
16 Same as No. 14 but softer. 104
17 As above, soft, friable, only slightly sandy (fine). 108
18 Chert Zone. 109
Unconformity
Eocene Series
Ocala Group
Crystal River Formation
19 Partially recrystallized limestone (calcarenite, al- 110
most a calcirudite), very pale orange, finely crystal-
line in part, firmly cemented with calcite, clayey,
moderate intergranular porosity, microfossiliferous-
Lepidocyclina ocalanus and Gypsina globula present.
(Turritella Zone of Hunter as described under section
on Paleontology)
20 As above, abundant echinoids Rhyncholampas 114
gouldii present. (Turritella Zone of Hunter as de-
scribed under section on Paleontology)
21 Partially recrystallized limestone (calcarenite al- 115
most a calcirudite), very pale orange, chalky to fine-
ly crystalline in part, firmly cemented with calcite,
moderate intergranular porosity, microfossiliferous-
Lepidocyclina ocalanus and Gypsina globula pres-






BUREAU OF GEOLOGY


Depth in feet from
Sample No. Description top of Quarry Face
ent, abundant miliolids, algal fragments, macro-
moldic.
22 As above, a black mineral present in matrix (may 117
be weathered glauconite), Lepidocyclina ocalanus
and Gypsina globula present.
23 As above. 119
24 As above, contains abundant Lepidocyclina ocalanus 123
and Gypsina globula present.
25 As above. 128
26 As above. 130
The section of Suwannee Limestone exposed here shows a series of
alternating hard with thinner soft beds that have weathered to a very
nodular appearing limestone. Beds, blebs and lenses of green clay
occur in the post-Suwannee and Suwannee Limestone sections. At the
contact of the Suwannee Limestone and the underlying Crystal River
Formation a massive chert bed occurs and is up to one foot thick. This
chert bed generally occurs throughout the quarry and provides a
convenient marker for the base of the Suwannee Limestone. Several
thinner chert beds occur above this one in the Suwannee Limestone.

5. Locality LHr22S-20E-4db: In an abandoned hard rock
phosphate pit boulders of silicified Suwannee Limestone
containing Rhyncholampus gouldii and boulders of crys-
talline, macromoldic limestone (calcarenite) overlie about
ten feet of Eocene-Crystal River Formation which occurs
as limestone pinnacles in the pit.
6. Locality LHr22S-20E-18ba: In an inactive quarry about 73
feet of crystalline to partially recrystallized limestone
(calcarenite) is exposed. Clay pockets 25 to 30 feet thick
occur in the section. The section exposed here shows a
series of alternating hard and soft rubbly beds. Chert beds
occur at the base of the quarry.
7. Locaity LHr22S-20E-21db: The following descriptions are
of samples taken from the north face of the quarry for-
merly operated by McDonald Corporation located in the
SE1/4 NE1/4 sec. 21, T22S, R20E.
post-Suwannee limestone
1 Partially recrystallized limestone (calcilutite), very 0
pale orange, chalky to finely crystalline in part, ce-
mented with calcite (hard), sandy (very fine to fine
with some medium) silty and clayey, trace of heavy
minerals, low to moderate intergranular porosity,






BULLETIN NO. 54


Depth in feet from
Sample No. Description top of Quarry Face
microfossiliferous, however, recrystallization makes
identification of the fossils difficult.
2 As above, very sandy in part and contains medium 3
size quartz grains.
3 As above, predominantly crystalline, not as sandy. 6
Oligocene Series
Suwannee Limestone
4 Crystalline limestone (calcarenite), very pale orange, 9
very finely crystalline, cemented with calcite (hard),
sandy, silty and clayey, manganese stained, low
porosity, microfossiliferous, slightly macromoldic-
Rhyncholampas gouldii present.
5 As above, but contains more clay. 12
6 Crystalline limestone (calcarenite), very pale orange, 15
very finely crystalline, cemented with calcite (hard),
sandy (very fine to fine), silty and clayey, low to
moderate moldic porosity, microfossiliferous-Ro-
talia mexicana identified, macromoldic.
7 As above, but more microfossiliferous. 18
8 As above. 21
9 Crystalline limestone (calcarenite), very pale orange 24
to pale orange, very finely crystalline, cemented
with calcite (hard), sandy (very fine to fine) silty
and clayey, manganese stained, low intergranular
and moldic porosity, slightly microfossiliferous-Ro-
talia mexicana present, macromoldic.
10 Same as No. 7 and No. 8. Rotalia mexicana present. 27
11 Sample as above with some pale blue green clay 31
present.
The section exposed here shows a series of alternating hard and
thinner soft beds that have been weathered to a very nodular appearing
limestone. Throughout the quarry lenses and blebs of green clay occur
in the limestone. Also apparent are steeply dipping beds, probably
representing slump structures resulting from solution.
8. Locality LHr22S-21E-19ab: In an abandoned hard-rock
phosphate pit six feet of crystalline limestone (calcarenite)
overlies the Eocene-Crystal River Formation. The Crystal
River occurs as pinnacles in the pit.
Pasco County:
1. Locality LPs25S-19E-llbc: 1.2 miles east of intersection
of State Highway 583 and 52 on the south side of State
Highway 52, partially recrystallized limestone (calcaren-






BUREAU OF GEOLOGY


Depth in feet from
Sample No. Description top of Quarry Face
ite) containing Rhyncholampas gouldii lies upon the spoil
bank of a shallow dug pit. The limestone was not observed
in place but is believed to have come from the pit.
2. Locality LPs23S-21E-26a: The following section was
measured in an abandoned quarry (known as McLeod Pit)
located in NW1/4 sec 26, T23S, R21E.
Thickness
Beds Description in Feet
Oligocene Series
Suwannee Limestone
4A Partially recrystallized limestone (calcarenite), light gray, 7.0
chalky, finely crystalline in part, firmly cemented with cal-
cite, sandy (very fine to fine), trace of heavy minerals,
high intergranular porosity, microfossiliferous, abun-
dant smooth ostracods present. The matrix of the rock
contains pebbles of very pale yellowish brown, crystal-
line, hard, finely sandy calcarenite.
Bed 4A occurs on the north face of the quarry and may be strati-
graphically equivalent to bed 4 below. Bed 4A is thin bedded and
consists of alternating soft and hard beds varying in thickness from
34 inch to 4 inches thick (fig. 7). Toward the bottom of bed 4A, the sedi-
ments become soft and massive.
Beds 1 through 4 below were measured on the west face, near the
south end of the quarry.
4 Partially recrystallized limestone (calcarenite), very 6.0
pale orange, chalky, finely crystalline in part, firmly
cemented with calcite, sandy (very fine to fine),
trace of heavy minerals, high intergranular porosity,
microfossiliferous-Rotalia mexicana identified, mac-
romoldic.
3 Crystalline limestone (calcarenite), very pale orange, 2.0
finely crystalline, cemented with calcite (hard),
sandy (very fine to fine), trace of heavy minerals,
high intergranular porosity, microfossiliferous-Ro-
talia mexicana, very macromoldic. Bed contains clay
inclusions ranging in size from blebs to large
pockets.
2 Crystalline limestone (calcarenite), very pale orange, 6.0
finely crystalline, cemented with calcite (hard),
sandy (very fine to fine), trace of heavy minerals,
high moldic and intergranular porosity, microfossil-






BULLETIN NO. 54


Thickness
Beds Description in Feet
iferous-Rotalia mexicana present, macromoldic-
Rhyncholampus gouldii present.
1 Crystalline limestone (calcarenite), very pale orange, 4.0
finely crystalline, very firmly cemented with calcite,
sandy (very fine to fine), trace of heavy minerals,
high intergranular porosity, very microfossiliferous-
Rotalia mexicana, Sorites sp. identified, macro-
moldic, Bryozoa present.
Total Thickness
(Beds 1-4) 18.0
Polk County:
1. Locality LPo25S-23E-30ca: In a quarry on the east side of
State Highway 471, 2.35 miles north of intersection with
U. S. Highway 98, silicified boulders of Suwannee Lime-
stone overlie the Crystal River Formation of Eocene Age.
2. Locality LPo26S-23E-30bc: Northwest of Kathleen, Polk
County, about 25 feet of Suwannee Limestone is exposed
in a test pit.
The following localities of Crystal River Formation of
Eocene Age were used in preparing the stratigraphic cross
sections and contour maps in this report:
Hernando County:
1. Locality LHr22S-17E-19ad: Crystal River Formation of Eo-
cene Age exposed in the bank of a ditch on the east side of
State Highway 595 just north of intersection of State High-
ways 50 and 595.
2. Locality LHr23S-21E-lbc: About three feet of Crystal River
Formation of Eocene Age is exposed in an abandoned
quarry located just north of State Highway 50 and 0.4
miles east of intersection of U.S. Highway 301.
3. Locality LHr22S-21E-36bc: About three feet of Crystal River
Formation of Eocene Age is exposed in a small quarry 1.40
miles north of intersection of U. S. Highway 98 and State
Highway 50 on the east side of U. S. Highway 301.
Sumter County:
1. Locality LSm21S-21E-19cd: In a quarry located north of
State Highway 476, 0.7 miles east of the Withlacoochee
River, Crystal River Formation of Eocene Age is being mined.

STRATIGRAPHIC RELATIONSHIPS

The Suwannee Limestone is known to be unconformable with the






BUREAU OF GEOLOGY


older Crystal River Formation and the younger Hawthorn Formation in
Citrus County (Vernon, 1951, p. 177). The top of the Crystal River Forma-
tion in the area of study is irregular (fig. 7) and appears to be un-
conformable with the overlying Suwannee Limestone.
At the Lansing Quarry the Suwannee is underlain by a massive chert
bed of variable thickness that may represent an unconformity. Below
the chert to the bottom of the quarry a limestone section occurs which
has a different lithology and overall bedding characteristics that is dif-
ferent than those of the Suwannee Limestone. The lithology of the beds
below the chert zone is similar to those deposits mapped elsewhere
in the area as Crystal River (Ocala Limestone of Carr and Alverson, 1959)
and because of this similarity they are placed in the Crystal River
Formation.
Hunter (written communication, 1970) found several species of
mollusks and echinoids (see Turritella martinensis zone under Paleon-
tology) in the limestone that occurs from four to five feet below the
chert bed which the writers place in the Crystal River Formation. These
species are also reported from Jackson and Vicksburg sediments in
Mississippi, as well as from the intermediate Forest Hill Sand-Red Bluff
Clay sequence. In this same interval, Puri (personal communication,
1971) identified Lepidocyclina ocalanus and Gypsina globula of upper
Eocene age. The discrepancy in the age of the fossils makes the dating
of this four to five foot section uncertain, and additional work on the
paleontology will be required before a definite age can be assigned to
this interval.
According to Shannon (1967, p. 47) the upper portion of the Su-
wannee Limestone in the Brooksville area appears to be stratigraphically
higher than the Suwannee elsewhere in the state. He based his conclu-
sion in part on the occurrence of the cone-shaped foraminifer Coskino-
lina which occurs at or near the contact with the Miocene in Jefferson
County, Florida. However, at the Lansing Quarry it occurs 30 to 50 feet
below the contact with post-Suwannee sediments which he placed in the
Miocene.
The writers found that Coskinolina floridana is absent in the upper
portion of the Suwannee at the Lansing quarry as well as in other areas
of Hernando and Pasco counties. However, in the lower portion of the
Suwannee Coskinolina is very common.
Microscopic examination and chemical analyses of the rocks at Lan-
sing 'indicate a change in the lithology about 18 feet below the first
occurrence of limestone in the quarry. The grain size of the limestone
changes from an overlying calcilutite downward to a calcarenite. The
basal limestone conglomerate at the top of the Suwannee Limestone found
at the Camp Quarry, (fig. 8-11) described by Randazzo (see Part II)
and the writers, as well as the limestone conglomerate observed by the






BULLETIN NO. 54


writers at the Brooksville Rock Quarry, is not present at the Lansing
Quarry. The absence of the limestone conglomerate makes the determi-
nation of the contact between the Suwannee and overlying fine grained
limestone deposits at Lansing more difficult. However, the apparent
absence of fossils, an upward change in the section from a calcarenite
to a calcilutite and the influx of more plastic material in the upper ten
feet of the section, indicates the depositional environment did change.
This uppermost post-Suwannee limestone unit (figure 12), also ob-
served at the Brooksville, Camp, and McDonald quarries described
from the deposits found along the subsurface high into Pasco County,
is believed to be stratigraphically higher than the sediments described
by the writers as Suwannee Limestone in Hernando and Pasco coun-
ties. The contact between this unit and the underlying Suwannee is
believed to be unconformable based on the presence of the previously
mentioned basal conglomerate, the apparent absence of fossils in the
upper unit and a change in lithology.
Solution pipes and collapse features (sinkholes), formed on the
Suwannee surface and apparent at the quarries around Brooksville (fig-
ure 13), are filled with plastic material of probable Miocene or younger
age, indicating an unconformity between them and the Suwannee Lime-
stone.
As illustrated in the contour maps (fig. 5 and 6) and in the series of
stratigraphic cross sections (fig. 7) the top of the Suwannee Limestone is
irregular and apparently unconformable with younger overlying deposits.
M11 z N-15RZ- rr-. Q~xin= Mk 1 -. Tr M wu = Wm k .


r , .; *. it.
Figure 12. Contact of post Suwannee limestone and Suwannee Limestone at Brooks-
ville Rock Company Quarry, Hernando County.






BUREAU OF GEOLOGY


*1--~


Figure 13. Filled sinkhole developed in Suwannee Limestone. Also note the bedded
nature of limestone to right of sink.

PALEONTOLOGY

A detailed paleontological investigation was not carried out but
diagnostic foraminifera described by other workers were noted through
careful microscopic examination of samples collected from the area.
Many forms of mollusks occur in the Suwannee Limestone of the area.
As reported by Carr and Alverson (1959, p. 11) the echinoid Rhyncholam-
pus gouldii Bouve is very common and apparently a diagnostic macro-
fossil.
The mollusks of the Suwannee Limestone were described by Mans-
field (1937). Those species that he (Mansfield, 1937, p. 48) considered
to be characteristic of the formation are: Orthaulax pugnax hernandoen-
sis Mansfield, Ampullina flintensis Mansfield, Chlamys brooksvillensis
Mansfield, Chione aff. C. bainbridgensis, Dall, Kuphus incrassatus Gabb,
and Rhyncholampus gouldii Bouve.
Hunter (written communication 1970) made the following comments
on the macrofossils from various quarries in Hernando County:
1. Lansing Quarry:
"The following species of fossil invertebrates have been collected
at the Lansing Quarry from rocks on the floor of the western most pit
beneath the water tower. All are believed to have come from that part
of the section exposed in this pit, which is above the upper ledge in the
complete exposure of the Suwannee in the main pit.






BULLETIN NO. 54


Echinoids: Rhyncholampus gouldii, Bouve (Abundant in the low-
est beds)
Phymotaxis mansfieldi, Cooke (Rare)
Mollusks: "Amauropsis" aff. burnsii meridionalis, Pilsbury
(Gastropods) Ampullina cf.flintensis, Mansfield
?Astrea sp.
Calliostoma cf. silicatum, Mansfield
Cerithium aff. vaginatum, Dall
Cerithium hernandoensis, Mansfield
Cypraea sp.
Potamides cf. cornutus, Heilprin
Scaphander sp.
(Bivalves) Xenophora sp.
Chama cf. lyelli, Dall
Phacoides hernandoensis, Mansfield
Trachycardium brooksvillense, Mansfield
Corals: Abundant fragments of several species of fine branch-
ing corals, as well as other types are present. None
were identified although it is possible that further
study may indicate genus and species of one or more
of the forms."
The following list with comments was provided by Hunter (1970) who
collected the specimens just below the first ledge above the floor of
the deepest and largest pit at the Lansing Quarry. She correlated this part
of the section with the Turritella martinensis Zone of Mac Neil (1944).
"Echinoids: Clypeaster aff. rogersi, Morton. This form has thinner
margins and smaller petal area than C. rogersi.
Rhyncholampus gouldii, Bouve
Mollusks: Turritella aff. martinensis, Dall (Exterior Molds)
Ostrea vicksburgensis, Conrad
Pecten sp. A (May be affiliated with P. anatipes, but
has 5 ribs instead of 4. Is badly worn.)
Pecten sp. B (aff. P. perplanus perplanus, Morton)
Pinna sp. (Interior Molds)
Foraminifera: Two species of Lepidocyclina appear to be represented,
as well as several other species.
'(1) The name and spelling Rhyncholampus gouldii for "Cassidulus goul-
dii" shown above is the accepted form, as recognized by Kier in his
"Revision of the Cassiduloid Echinoids," 1962.
'(2) Well preserved specimens of Ostrea vicksburgensis collected at
the Lansing pit agree in detail with specimens on hand from the Mint
Spring marl in Mississippi. The species also is reported from the Red Bluff
Clay-Forest Hill Sand sequence as well as the upper Jackson beds in that
state.






BUREAU OF GEOLOGY


'(3) The pectens all show varying degrees of wear. Species A is highly
suggestive of Pecten anatipes, but certain identification requires better
material. P. anatipes ranges from the Red Bluff Clay through the Byram
Formation. Species B is probably a variety of P. perplanus perplanus. In
the past much confusion has generated concerning these Eocene-Oli-
gocene pectens, but recently published studies indicate that the small
common form present in the Crystal River formation in Florida and
equivalent beds elsewhere is P. spillmani. P. perplanus perplanus is
found in the Red Bluff Clay; P. perplanus poulsoni in the Marianna lime-
stone and Mint Spring Marl.
'(4) The species of the Lepidocyclina could possibly be determined,
as structure is present in several on hand. These could be useful, as
Lepidocyclina chaperi and L. ocalanus are present in the Red Bluff Clay
and Bumpnose units, while L. mantelli is typical of Marianna Limestone.
For micropaleontologists dependent on well samples, this difference in
foraminifera might suggest a good boundary marker.
'The age of this zone and its more westerly equivalents is currently un-
certain. Faunas in different areas contain both Eocene and Oligocene ele-
ments, suggesting that it may represent a transitional period. However,
most of the literature I have seen shows the zone as "?Oligocene" in age."
2. Camp Quarry:
At the Camp Quarry located north of Route 50, west of Brooksville,
Hunter (1970) says that "although the general appearance and brecciated
condition of many of the rocks is suggestive of Tampa Limestone, no mol-
lusks, limited to the Tampa Limestone, either marine or terrestrial, were
seen. On the contrary, only species known to occur in the Suwannee
Limestone were recognized.
'From float in the bottom of the upper level of the pit, between the
wall opposite the access road and the pinnacle in the center of the quarry
floor, the following were collected:
Rhyncholampus gouldii, Bouve One specimen in rock apparently
from the fossiliferous bed discussed
below.
Kuphus incrassatus, Gabb This species, while common in Oli-
gocene beds,' is also present in beds
which have been reported as Tampa
limestone.
'At the base of the west wall of the pit, facing the access road, are
many large boulders which appear similar to beds exposed in the cut
above them. Although most of these were hard, brecciated limestones con-
taining fragments of varying sizes, rocks of one fossiliferous bed were
noted. These contained molds of the following species:
Orthaulax hernandoensis, Mansfield
Cerithium hernandoensis, Mansfield






BULLETIN NO. 54


Cerithium cf. brooksvillensis, Mansfield (Interior mold)
Ampullina sp.
Turritella sp. (May be new species. Does not resemble any of those
published in available literature.)
Chione cf. bainbridgensis, Dall
Trachycardium sp."
3. Florida Rock Products Quarry:
"A bed of hard limestone, containing Orthaulax hernandoensis and
other Oligocene species is present near the top of the section, overlying a
bed containing Kuphus incrassatus, at the Florida Rock Products Quarry
on Route 98, northwest of Brooksville. While none of the brecciated beds
were observed at this locality, similarity of the fossils present suggests
that the two fossiliferous beds may be equivalent, and may provide a
basis of correlation between the two quarries. At the Camp Quarry, this
bed contains a tremendous number of Orthaulax hernandoensis, Mans-
field. All specimens seen where the whorls of the spire were preserved,
revealed no trace of callus covering. The spires of both Orthaulax pugnax
of the Tampa Limestone, and Orthaulax gabbi of the Chipola Formation
are covered by callus."
The writers found that the upper part of the Suwannee described as
unit three under Lithology contains various genera of Foraminifera. How-
ever, the only forms the writer identified were Rotalia mexicana and
Sorites sp. The lower part of the section described as units one and two
under Lithology contains many Foraminifera. Some of these belong to
the families Valvulinidae (Coskinolina) and Rotaliidae (Discorinopsis and
Rotalia). According to Glaessner (1948, p. 185-186) Valvulinidae occurs
at depths up to five fathoms (30 feet) with temperatures 200 to 310 C.
and Rotaliidae may occur at all depths, but are very abundant at depths
that range from 0 to 5 meters (0 to 16.5 feet) and temperatures ranging
from 0 to 27 C. Henson (1950, p. 215-238) in his discussion of
reef formations in the Middle East points out that Miliolidae, Valvulini-
dae and Rotaliidae are some of the foraminiferal faunas associated with
what he calls fringing reefs and open shoal reefs.
Shannon (1967, p. 44) remarked that the fauna he described from
near the top of the Suwannee deposits at Lansing Quarry occurred in
waters 0 to 20 meters (0 to 65 feet) in depth and placed this interval in
what Phleger (1960, p. 258-259) referred to as the near shore turbulent
zone.
Mollusks are common throughout the Suwannee section. Hunter (1970)
reports that corals and the mollusk Orthaulax hernandoensis are very
abundant in the upper part of the Suwannee at the Camp Quarry and
says that Vokes and Yokes (1968, p. 71-72) states that the genus Or-
thaulax lived in a coral environment as well as a low energy back
reef environment.






BUREAU OF GEOLOGY


STRUCTURE

The largest geological structure affecting the area of study is a broad
gentle flexure called the Ocala Uplift (figure 14). According to Vernon
(1951, p. 54-55) the Ocala Uplift is approximately 70 miles wide and
230 miles long and extends from northern Polk County, Florida to the
Georgia border.
As pointed out in the following discussion the portion of the Ocala
Uplift in Sumter County lying adjacent to Hernando County probably had
a bearing on the configuration of the Suwannee deposits in the area of
study.
The configuration and altitude of the Suwannee limestone is shown by
the contour maps (fig. 5 and 6), and the stratigraphic cross sections (fig. 7)
further illustrate the altitude of the beds.
The contour maps show that an elongated subsurface high extends
from Pasco County northwestward into Hernando County. As shown on
the insert on figure 6, the contours of that portion of the high in Hernando
County show the Suwannee surface in much more detail.
The negative or subsurface low area between Dade City and Trilby,
Pasco County was drawn on data from one well. It is probably a result
of post-Suwannee erosion as the Suwannee is only 50 feet thick in this
particular well.
The high area just south of Trilby may have been originally connected
to the positive or high area to the west, but it has been separated by
subsequent erosion. The altitude and thickness of the Suwannee Lime-
stone in Hernando County (fig. 7) are such that by projecting its dip to the
east the Suwannee should cover the peninsula. However, Suwannee de-
posits are absent on the eastern side of Hernando County and the north-
eastern edge of Pasco County. Vernon (1951, figure 13) pointed out that
it does not occur above the crest of the Ocala Uplift east of Hernando
County.
At the end of the Oligocene Epoch, gentle arching of the region began
as the Ocala Uplift was initiated, and faulting occurred along the crest
and flanks of the uplift. Carr and Alverson (1959, p. 59-60) and Pride
and others (1966, fig. 9) propose the presence of a northwest-southwest
trending normal fault in northwest Polk County. This structural move-
ment may have caused the Eocene and Suwannee deposits along the
eastern portion of Hernando County and the northeastern corner of
Pasco County to become adjacent to one another (fig. 5, 6 and 7). As
the uplift progressed, the Suwannee seas regressed and erosion removed
that portion of the Suwannee deposited east of the fault cutting across
Hernando and Pasco counties. The Suwannee deposits to the west of
the fault were also subjected to erosion but were not totally removed.






BULLETIN NO. 54


Fault in Polk County after
Carr and Alverson (1959) and
Pride (and others 1966)


Figure 14. Map of Florida showing location of Ocala Uplift in a portion of
Florida and related faulting (modified after Vernon, 1951).

GENERAL SUMMARY OF DEPOSITIONAL HISTORY

During the early stages of Suwannee deposition the environmental
conditions in the area of study appear to be similar to those that oc-
curred in the type area of the formation, along the upper Suwannee






BUREAU OF GEOLOGY


River. This conclusion is substantiated by paleontological evidence, simi-
lar lithologies (except for detrital quartz sand found in the Suwannee
deposits in the area of study) and similar bedding characteristics.
Detrital material is present throughout the section in the study area,
with a greater influx of elastic sediments toward the latter stages of
deposition. The peat associated with the carbonates in Pasco County
suggests that during the early part of Suwannee time there was probably
a very shallow, warm water environment where marine and plant life
thrived.
Even though definite evidence is lacking, the subsurface topographic
high (fig. 5, 6 and 7) may represent a carbonate bank formed on top
of the Eocene-Crystal River Formation which built up progressively
throughout the Oligocene. The predominance of calcarenites, bedding
characteristics, and paleontological evidence leads the writers to con-
clude that the carbonate sediments associated with this feature were
deposited in a warm shallow sea.
The environmental evidence inferred by the presence of corals,
Orthaulax, Miliolidae, Valvulinidae and Rotaliidae indicate that reefs
may have developed on the carbonate banks. However, more detailed
petrographic and paleontological work will have to be done before this
can be stated with certainty.

ECONOMIC GEOLOGY

Analyses of the Suwannee Limestone indicates that it is essentially a
"high calcium" rock that ranges from 92.91 percent to 99.56 percent
calcium carbonate, and as pointed out by Ketner and McGreevy (1959,
p.58) it contains less than 0.2 percent P205 and less than 0.1 percent
Al203.
Over the years several companies have mined the Suwannee Limestone
in Hernando and Pasco counties. However, currently there are only
three active mines near Brooksville, Hernando County.
The open pit mining methods used by the companies in Hernando
County are generally the same. Prior to opening a new quarry face the
brush, trees, sand, and clay overburden are cleared away by bulldozing.
Shot holes are then drilled into the rock and the quarry face is shattered
by dynamite. The shattered rock is loaded by dragline onto trucks and
transported to the rock crushers for processing (figure 15). Both the
interbedded hard and soft layers are mined, but only the hard limestone
is used. The soft layers and clay are washed away and stored in tailings
ponds.
The geographic distribution of the Suwannee Limestone which the
writers believe can be utilized for concrete aggregate is shown in figure
16. It should be pointed out that the area designated for potential con-






BULLETIN NO. 54 39


. J' .----- ^ w^



figure 15. Camp Concrete and Rock Company Quarry, showing transportation of
rock to plant crusher.


Figure 16. Hatchered area indicates distribution of potential limestone aggregate
in Hernando and Pasco counties.





BUREAU OF GEOLOGY


create aggregate is based on the study of samples from existing quarries
and well cuttings, and therefore the delineation is generalized.
As previously mentioned, the karst surface developed on top of the
Suwannee Limestone makes the thickness of the formation variable.
A comparison between the contour map of the top of the Suwannee Lime-
stone and the topographic maps of the area indicates that the subsurface
highs and lows of the rock surface seem to conform to the surface
topographic highs (hills) and lows (valleys). This point is particularly
well illustrated by the geographic position of the quarries near
Brooksville which not only are located on the subsurface limestone
highs but also on topographic highs (hills). It is also interesting to note
that in most cases the mining at the quarries begins along the slopes of
the surface highs (hills) and the overburden is removed as the mining
operation cuts into the hills.
The writers suggest that in prospecting for concrete aggregate the
sites for drilling should be chosen by combining the use of the contour
map of the top of the Suwannee Limestone with topographic maps of the
area. To penetrate as little overburden as possible before reaching the
top of the limestone it will be necessary to superimpose the contour map
of the top of the Suwannee Limestone on the topographic map in order
to determine where the limestone surface is equal to the land surface
rand to then drill at that point.
The potential concrete aggregate area in Pasco County is also based on
study of cuttings from water wells but it is not as desirable for a prospec-
tive area as Hernando County because there are potentially greater
amounts of material overlying the limestone.







BULLETIN NO. 54


BIBLIOGRAPHY


Alverson, D.C.
(see Carr, W.J.)
Carr, W.J.
1959 (and Alverson, D.C.) Stratigraphy of middle Tertiary rocks in part of west-
central Florida: U.S. Geol. Survey Bull. 1092, p. 11-60.
Cherry, R.N.
(see Pride, R.W.)
Clapp, F.G.
(see Matson, G.C.)
Cooke, C.W.
1929 (and Mossom, Stuart) Geology of Florida: Florida Geol. Survey 20th Ann.
Report, p. 29-229.
1936 (and Mansfield, W.C.) Suwannee limestone of Florida (abstract): Geol. Soc.
Amer. Proc., 1935, p. 71-72.
1945 Geology of Florida: Florida Geol. Survey Bull. 29, 339 p.
Dall, W.H.
1892 (and Harris, G.D.) Correlation papers-Neocene: U.S. Geol. Survey Bull. 84,
p. 107.
Glaessner, M.F.
1948 Principles of Micropaleontology, Melbourne University Press, Carlton,
Victoria, P. 185-186.
Harris, G.D.
(see Dall, W.H.)
Henson, F.R.S.
1950 Cretaceous and Tertiary formations and associated sediments in Middle
East: Am. Assoc. Petroleum Geologists Bull., v. 34, no. 2, p. 215-238.
Hunter, M.E.
1970 Identification of the invertebrate fauna from several limestone quarries in
Hernando County, Florida: (Written Communication, 1970) Coastal Petrol-
eum Company, Pinellas Park.
Ketner, K.B.
1959 (and McGreevy, L.J.) Stratigraphy of the area between Hernando and Hardee
Counties, Florida: U.S. Geol. Survey Bull. 1074-C, p. 57-59.
MacNeil, F.S.
1944 Oligocene stratigraphy of southeastern United States: Am. Assoc. Petroleum
Geologists, p. 1317.
1946 The Tertiary formations: Southeastern Geol. Soc. (Guidebook), 4th. Field Trip,
southeastern Alabama, September, p. 48-49.
1947 Correlation chart for the outcropping Tertiary formations of the eastern
Gulf region: U.S. Geol. Survey Oil and Gas Inv. Prelim. Chart 29.
McGreevy, L.J.
(see Ketner, K.B.)
Mansfield, W.C.
(see Cooke, C.W.)
1937 Mollusks of the Tampa and Suwannee limestones of Florida: Florida Geol.
Survey Bull. 15, 334p.






42 BUREAU OF GEOLOGY


Matson, G.C.
1909 (and Clapp, F.G.) A preliminary report of the geology of Florida with special
reference to the stratigraphy: Florida Geol. Survey 2nd Ann. Rept., p. 141-145.
Meyer, F.W.
(see Pride, R.W.)
Mossom, Stuart
1925 A preliminary report on the limestone and marls of Florida: Florida Geol.
Survey 16th Ann. Rept., p. 78-79.
(see Cooke, C.W.)
1926 Review of the structure and stratigraphy of Florida: Florida Geol. Survey
17th Ann. Rept., p. 109-275.
Phleger, F.B., Jr.
1960 Sedimentary patterns of microfaunas in northern Gulf of Mexico, in Recent
sediments, northwest Gulf of Mexico: Am. Assoc. Petroleum Geologists,
p. 258-259.
Puri, H.S.
1971 Comments on Foraminifera from Lansing quarry, Hernando County, Florida
(Personal Communication, 1971) Bureau of Geology, Tallahassee.
Pride, R.W.
1966 (and Meyer, F.W. and Cherry, R.N.) Hydrology of Green Swamp area in
central Florida: Florida Geol. Survey Rept. of Inv. No. 42, p. 31-33.
Shannon, D.L.
1967 Comparison of the Foraminiferal faunas on both sides of the Tampa-Suwannee
contact in Florida: Unpublished Master's Thesis, Florida State University.
Vokes, H.E.
1968 (and Vokes, E.H.) Variation in the genus Orthaulax (Mollusca: Gastrapoda):
Tulane Studies in Geol., Tulane Univ. of La., New Orleans, Vol. 6, No. p. 71-72.
Vernon, R.O.
1951 Geology of Citrus and Levy Counties, Florida: Florida Geol. Survey Bull. 33,
256 p.
Wetterhall, W.S.
1964 Geohydrologic reconnaissance Pasco and southern Hernando Counties,
Florida: Florida Geol. Survey Rept. of Inv. No. 34, p. 8-12.







PART II
BULLETIN NO. 54
















PETROGRAPHY OF THE SUWANNEE LIMESTONE



By
Anthony F. Randazzo






















Tallahassee, Florida
1972
1








CONTENTS




Acknowledgements ..................................................... v
Introduction.............................................. .............. 1
Petrography.............................................. .............. 4
B iopelsparite......................................................... 4
Biosparite.............................................. .............. 4
Sandy Intrasparite ........................... ............. ............. 4
Sandy Pelmicrite ............................. ........... .............. 7
Porosity............................................... .............. 7
Paleoenvironmental Interpretations ...................................... . 7
References Cited........................................ ............... 13






































iii







ILLUSTRATIONS


Figure
1 Verticle section at Camp Concrete and Rock Company
Quarry, Hernando County, Florida ..................................... 2
2 Photomicrograph of Biopelsparite from Camp Concrete
and Rock Company Quarry, Hernando County, Florida. ................... 5
3 Photomicrograph of Biosparite from Camp Concrete and
Rock Company Quarry, Hernando County, Florida ...................... 5
4 Photomicrograph of Sandy Intrasparite from Camp Concrete
and Rock Company Quarry, Hernando County, Florida. ................... 6
5 Photomicrograph of Sandy Pelmicrite from Camp Concrete
and Rock Company Quarry, Hernando County, Florida. ................... 6
6 Variations of micrite and sparite percentages among the
samples of the verticle section ........................................ 8
7 Variations of fossil, pellet, intraclast, and detrital quartz
percentages among the samples of the verticle section. ..................... 10




TABLES

1. Results of point counting. Percentages have been rounded
off to nearest whole percent ........................................... 3







ACKNOWLEDGEMENTS


I wish to thank Daniel A. Textoris (University of North Carolina) for
his critical reading of the manuscript and his suggestions for its improve-
ment.
Initial investigation of this research was supported through a
summer research faculty fellowship from the Graduate School of the
University of Florida. The Florida Bureau of Geology provided funds for
thin sections and photographic supplies.
























ERRATA
Author's name Randazza
not Rondazzo
Location of Camp
quarry should be
Sec. 8, T22S, R19







PETROGRAPHY OF THE SUWANNEE LIMESTONE

By
Anthony F. Rondazzo

INTRODUCTION

The true character of the Suwanee Limestone can be ascertained best
by thin section studies. The petrography of this formation has never
been determined. In order to describe and recognize the nature of the
limestones present and investigate the relationships observed or sus-
pected in megascopic observations, a typical exposure was selected
for sampling. Specimens were collected vertically from the south wall
of the Camp Quarry located near Brooksville in the NW 14 SW 3
Sec. 8, T22S, R18E. These samples were taken at approximately one-
foot intervals wherever possible. Thin sections were prepared for 27
of these samples. The petrographic analysis which resulted in the
establishment of microfacies took into consideration mineralogy,
original texture, clastic and-'-hemical constituents, diagenetic effects,
and paleontology. Petrographic nomenclature follows that of Folk (1962).
Approximately 300 points were counted for each slide resulting in
an accuracy of - 4 percent in the 10-80 percent range according to
van der Plas and Tobi (1965). Results of point counting are presented
in Table 1.
A preliminary set of four microfacies was recognized in the vertical
section. This set demonstrates the petrographic nature of the formation
in this area but can be applied to megascopically similar rocks in the
region. The calcilutite, described megascopically in the field, contains
the sandy pelmicrite and sandy intrasparite facies and the calcarenite
includes the biopelsparite and biosparite microfacies. Future petro-
graphic studies in nearby areas, as well as in the type section in
Suwannee County, will better define the Suwannee limestone and sub-
stantiate megascopic observations. The vertical distribution of these
facies is shown in figure 1. The biopelsparite and biosparite facies are
confined to the lower % of the section, while the sandy pelmicrite and
intrasparite are found in the upper 34.






BUREAU OF GEOLOGY


Height Specimen
65 0'-r -----I No.


SAN DY
PELMICRITE


SANDY
INTRASPARITE


.%. BIOSPARITE



E BIOPELSPARITE


Figure 1. Verticle section at Camp Concrete and Rock Company Quarry, Her-
nando County, Florida.















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'-C


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BULLETIN NO. 54










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BUREAU OF GEOLOGY


PETROGRAPHY


BIOPELSPARITE

Five thin sections are representative of this microfacies. The
specimens at the bottom of the section (figure 1) contain more micrite
and are more poorly sorted than those found interbedded with biosparite
in the central part of the column. Fossils represent the principal allo-
chemical constituent and include intact and fragmented foraminifers,
algae, bryozoans, pelecypods, gastropods, echinoderms, and ostracods.
The pellets are probably fecal in origin, ovoid, moderately well sorted
and vary from 0.2 mm. to 0.03 mm. Modest percentages of intraclasts
are present. These allochems range in size from 1.15 mm. to 0.2 mm.
and include composite grains. Some recrystallization of micrite to
microspar and pseudospar has occurred but sparry calcite is the most
abundant orthochemical constituent (figure 2).


BIOSPARITE

Biosparite is the most abundant microfacies and is represented
by fourteen of the thin sections (figure 3). It occurs in the central part
of the vertical section (fig. 1) and interbedded in places with biopel-
sparite. Sparry calcite is very abundant, comprising some 30-50 per-
cent of many of the samples. Micrite content usually ranges from 10-
15 percent. Fossils are the chief allochemical component, in some
cases, making up 40 percent of the rock. Whole and fragmented fora-
minifers, algae, bryozoans, pelecypods, gastropods, echinoderms, and
ostracods are all present. Other allochemical constituents, such as in-
traclasts and pellets, are in minor abundances.


SANDY INTRASPARITE

Overlying the uppermost biosparite is the sandy intrasparite
facies from which two thin sections were studied (fig. 1, 4). This facies
is characterized by having a high percentage of intraclasts and com-
posite grains made up of subangular to rounded sand and pebble-
sized particles of micrite most often containing quartz grains, pellets,
and occasional fossils. This facies differs considerably from the pre-
viously mentioned two microfacies in the almost complete absence
of fossils and in the greater abundance of detrital sand-sized quartz
grains. Calcite spar is the principal orthochemical component but






BULLETIN NO. 54


0 0.5mm
" I


Figure 2. Photomicrograph of sample No. 25 Biopelsparite; foraminifers, assorted
skeletal fragments and pellets in sparry calcite cement; X-Nichols.


0 0.5mm


Figure 3. Photomicrograph of sample No. 14 Biosparite; micritized foraminifers
in a mosaic of sparry calcite cement; X-Nicols.






BUREAU OF GEOLOGY


0 0.5mm
t .. I


Figure 4. Photomicrograph of sample No. 11 Sandy Intrasparite; large
composite grains associated with detrital quartz grains and some micrite
in sparry calcite cement; the large composite grain here contains quartz
grains, pellets, intraclasts and micrite; plain polarized light.


0 0.5mm


Figure 5. Photomicrograph of sample No. 7 Sandy Pelmicrite; pellets, intra-
clasts, and detrital quartz grains in micrite; several patches of pseudospar
are present; X-Nicols.






BULLETIN NO. 54


specimen No. 11 did show an appreciable amount of recrystallization
of micrite to microspar and pseudospar.


SANDY PELMICRITE

The top 14 feet in the quarry section contains the sandy pelmi-
crite facies (fig. 1, 5). Six thin sections were studied from this micro-
facies. Pellets, intraclasts, and composite grains are the principal
allochemical constituents. Detrital quartz grains are also present.
Micrite and recrystallized microspar are abundant, while spar and
pseudospar are minor constituents of this facies. The almost complete
lack of fossils, and the increase of detrital sand-sized quartz grains
found in the sandy intrasparite facies, is also true for this facies.


POROSITY

The visible porosity of these rocks, measured in thin section,
varies among facies. The sandy pelmicrite facies has the lowest poros-
ity ranging from 1-8 percent. The other facies have somewhat higher
porosities, ranging from 1-40 percent, with values of 5-20 percent most
representative. The porosity of the biosparite is slightly higher than the
others.
Porosity is most commonly of three types, vug, intergranular
including both interparticle and intercrystal), and moldic. The inter-
granular and moldic types are fabric selective (Choquette and Pray,
1970) but the vug type is not. Most of the porosity is secondary involv-
ing postdepositional solution of aragonite mollusk shells and the en-
largement of the other fabric selective pores. Sparry calcite cement,
where abundant, has destroyed most of the primary porosity in those
specimens. The low visible porosity of the sandy pelmicrite facies is
attributed to its higher micrite content. This facies probably possessed
a higher intergranular porosity than was observed but the pore spaces
are too fine to be seen. Most of the spaces encountered in the various
facies would be classified according to Choquette and Pray's (1970)
classification as micro (less than 1/16 mm. average diameter) and
small mesopores (1/16 M mm. average diameter).


PALEOENVIRONMENTAL INTERPRETATIONS

The data presented in Table 1 have been plotted in figures 6 and
7 in order to detect significant trends. Figure 6 is a plot of the micrite








BUREAU OF GEOLOGY


Figure 6. Variation of micrite and sparite percentages among the samples of the
vertical section.



and sparite contents. The micrite-sparite content is a general indicator
of energy levels at the depositional site. In low ei _'. environments,
such as a protected lagoon, lime mud may be allowed to accumulate
and sparry calcite cement would not be an important part of the lithifi-
cation process. In a more energetic environment, lime mud may be
winnowed leaving pore spaces among the allochemical constituents


Specimen
No.







BULLETIN NO. 54


which may later be filled with diagenetic sparry calcite cement. Be-
cause of the higher degree of error from the actual variation of thin
section components counted than from variations from slide to
slide, percentage changes of ten percent or less between samples are
not significant. More significant are the greater percentage differences
of constituents from sample to sample. The micrite-sparite trends
observed in figure 6 show a significant increase in sparite content
from sample no. 9 to no. 11 (approximately 16 feet below the top of
the quarry). This increase in sparite content plateaus for the samples
in the central and lower parts of the section. The micrite content
also shows some rather dramatic changes at the same sample position
(no. 9 and no. 11). The micrite content remains low except for a no-
ticeable increase at the bottom of the section (samples no. 37 and no.
38). This is accompanied by an increase in sparite for these two samples.
The changes in trend reflect the microfacies established above.
In order to apply the energy concept to these variations in the
recognition of transgressive and regressive phases of the sea, assump-
tions must be made with regard to geomorphic position of this area
as a depositional site during Oligocene time. Lime mud indicates a
low energy environment which can exist in a number ot different
environments including shallow water lagoonal, supratidal, inter-
tidal and shallow and deep subtidal. When additional vertical sections
are studied petrographically, the relative geomorphic positions of
the sections should be ascertained. Because such data are not avail-
able at this time, several assumptions will be investigated in order to
gain some insight as to the nature of the environment of deposition.
One assumption will start with samples No. 37 and No. 38 representing
a near shore low energy environment where there has been sufficient
water agitation to remove some lime mud with the infilling of spar at
a later time. A transgression of the sea would be represented by the de-
crease in micrite content in specimens No. 36 through 13. The envi-
ronment may have now changed to a shallow subtidal area where wave
base produced noticeable winnowing of micrite. Specimens No. 12 and
No. 11 show the beginning of another change because of the rapid
decrease in spar accompanied by an increase in micrite... This could
be interpreted as a regression of the sea and a return to quiet water
conditions where lime mud could accumulate and specimens No. 9
through No. 2 formed.
Another interpretative alternative would start with specimens No. 37
and No. 38 representing a deep water subtidal environment where water
agitation of the bottom was variable, allowing some lime mud to accumu-
late. Specimens No. 36 through No. 13 would represent a regression of
the sea allowing wave base to become an important factor in the winnow-
ing of micrite. A general high energy environment, probably shallow









BUREAU OF GEOLOGY


37- y ,
-38-
f --5 3b
Figure 7. Variation of fossil, pellet, intraclast, and
among the samples of the vertical section.


4:0
detrital


5b 60%
quartz percentages


subtidal and perhaps intertidal, would result. Specimens No. 12 and No. 11
would indicate another sea transgression with deeper waters returning.
Accompanying this return of the sea would be lower energy conditions


Specimen
No.
2-
4-


-INTRACLASTS






BULLETIN NO. 54


allowing more lime mud to accumulate. Specimens No. 9 through No. 2
would represent this depositional phase.
Still another approach to the resolvement of the question of which
assumption is more likely to have fit actual conditions, would be
analysis of allochemical components of the samples. Percentages of
fossils, intraclasts, pellets, and extrabasinal detrital quartz grains were
plotted in figure 7. Allochems can aid in the deciphering of energy con-
ditions as well as geomorphic conditions of the depositional environment.
The occurrence of detrital quartz, most probably derived from a positive
area to the northeast, (initial effects of the Ocala Uplift?), is useful as a
guide for determining nearness to shore. The variations plotted in figure
7 best meet the conditions of the first interpretative assumption made for
figure 6. Assuming a near shore low energy environment existed when
specimens No. 37 and No. 38 formed, the lack of detrital material could
be explained by the negativeness of the land mass. A transgression of
the sea would have placed the land farther away resulting in the lack
of extrabasinal material. If this transgression were accompanied by a
higher energy level, as indicated by the lower micrite-sparite ratio, the
open sea conditions may have been more conducive for marine life
to flourish. This would account for the fossil percentages of specimens No.
36 through No. 13. The intraclast and pellet percentages for these samples
are not indicative of energy level or water depth changes.
The regression of the sea and the return to shallow water conditions
could account for the sudden increase in interclast and detrital quartz
content. Specimens No. 12 and No. 11 may represent a time when water
agitation at wave base could have caused substantial tearing up of the
sea floor, creating intraclasts and the new environment may have been
detrimental to marine life as evidence by the lack of fossils. A nearness
to shore would account for the detrital quartz. Continual regression could
then have resulted in the return to lower energy shallow water conditions
under which specimens No. 9 through No. 2 formed.
An additional possibility exists regarding this last hypothesis. The
rather striking differences in allochemical constituents being accumulated
at the position of specimen No. 13 could be interpreted as a disconfor-
mity of uncertain magnitude. Specimens No. 12 and No.11 could represent
a basal conglomerate signifying another transgressive phase of the sea.
The lack of fossils could be attributed to a time lag in the ability of
marine organisms to reestablish themselves to this newly created marine
envornment. Field observations strongly suggest a difference in
lithologic character and environmental change to substantiate the
credibility of this petrographic interpretation. Specimens No. 12, 11, 9,
8, 7, 6, 4 and 2 may not be part of the Suwannee Limestone or even
Oligocene in age. The Suwannee Limestone may be a time transgressive
stratigraphic formation.






12 BUREAU OF GEOLOGY

To briefly summarize, the paleoenvironmental interpretation best
fitting the petrographic observations is as follows:
1) A near shore low energy environment existed when specimens
No. 37 and No. 38 formed.
2) A transgression of the sea accompanied by higher energy con-
ditions produced a shallow subtidal environment where
specimens No. 36, 34, 33, 31, 30, 28, 26, 25, 24, 23, 21, 18, 17,
16, 14, and 13 were deposited.
3) A regression of the sea removed a portion of the rock record
and created a disconformity.
4) The sea returned to the area with the deposition of a basal
carbonate conglomerate (specimens No. 12 and No. 11).
5) Low energy shallow water (probably intertidal) conditions
prevailed with the formation of specimens No. 9, 8, 7, 6, 4 and
2.





BULLETIN NO. 54 13

REFERENCES CITED

Choquette, P.W., and Pray, L.C., 1970, Geologic nomenclature and classi-
fication of porosity in sedimentary carbonates: American Assoc.
Petroleum Geol. Bull., v. 54, p. 207-250.

Folk, R.L., 1962, Spectral subdivision of limestone types, in classification
of carbonate rocks, W.E., Ham, Ed.: American Assoc. Petroleum
Geol., Memoir 1, P. 62-84.

van der Plas, L., and Tobi, A.C., 1965, A chart for judging the reliability
of point counting results: American Journal Science, v. 263, p. 87-90.







WHr-22S-20E-19bc LHr-22S-20E-21db
WHr-22S-19E-21dd L Qua2r
t LLHr-22S-


EXPLANATION
SPost-Suwonnee
q Crystalline Limestone (Suwannee Limestone)
Partially Recrystallized Ls.(Suwonnee Limestone)
Crystal River Formolion


EXPLANATION
-.I Suwonnee
___ iCrystal line Limestone (Suwonnee Limestone)
Partially Recrystallized Ls.( Suwonnee Limestone)
I_ i Crystal River Formation


0 I Miles
Approi Scale


WPs-25S-21E-8db WSm-24S-23E-31bb
WPs-25S-20E-lldd Sumter-Posco Co.Line
WPs-24S-18E-35cb ,i,\.c:.::::\. q Wilhlocoochee Rioer 100


bull ofMexico
50 w -4IS -44 Ps-25S-lYE-Sbc .....

{50

100
-150,


EXPLANATION
Post Suwonnee
Crystolline Limestone (Suwonneel
Partially Recrystallized Ls (Suwonnee)
Crystol River Formation


0 1 2 Miles
Approx Scale


L Hr-2S-18E-23dd WHr-22S-19E-o6ad Wir-Z3S-20E-32od

oo "......... '-"' ""-^ "' I I <.".. ";. / ..... ."" . '


50 a-


EXPLANATION
I. Posl-Suwannee
SCrystalline Limestone (Suwonnee Limestone)
Partially Recrystollized Ls.(Suwonnee Limestone)
SCrystal River Formoalion


EXPLANATION
O Well location
Quarry
+ Outcrop
A -A Line of cross section


0 2 4 6 Miles
Approx.Scole


LOCATION
Hrnandto-Pac
Countif1


0 2I Miles
Appros.Scoae


Figure 7. Stratigraphic Cross Sections along lines A-A', B-B', C-C' and D-D .


0 ? Miles
Approx.Scole


50


Gulf of Mexico
IPs-24 -I WPs-25S-17E-5bc




- i!
-I00-
-150-