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STATE OF FLORIDA
STATE BOARD OF CONSERVATION
DIVISION OF GEOLOGY




FLORIDA GEOLOGICAL SURVEY
Robert O. Vernon, Director






REPORT OF INVESTIGATIONS NO. 44





GROUND-WATER RESOURCES
OF POLK COUNTY

By
Herbert G. Stewart, Jr.











Prepared by the
UNITED STATES GEOLOGICAL SURVEY
in cooperation with the
DIVISION OF GEOLOGY
the
BOARD OF COUNTY COMMISSIONERS OF POLK COUNTY
and the
SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT
1966






FLORIDA STATE BOARD

OF

CONSERVATION


HAYDON BURNS
Governor


TOM ADAMS
Secretary of State



BROWARD WILLIAMS
Treasurer



FLOYD T. CHRISTIAN
Superintendent of Public Instruction


EARL FAIRCLOTH
Attorney General



FRED O. DICKINSON
Comptroller



DOYLE CONNER
Commissioner of Agriculture


W. RANDOLPH HODGES
Director






LETTER OF TRANSMITTAL


7torida geological Sarveu

Tallahasseo



August 16, 1966

Honorable Haydon Burns, Chairman
Florida State Board of Conservation
Tallahassee, Florida

Dear Governor Burns:
The Division of Geology of the State Board of Conservation is
publishing, as Report of Investigations No. 44, a detailed geologic
and hydrologic study, covering the "Ground Water Resources of
Polk County." This report was prepared by Mr. Herbert G. Stewart,
Jr., geologist with the U. S. Geological Survey, in cooperation with
the Board of Conservation, the Board of County Commissioners of
Polk County, and the Southwest Florida Water Management Dis-
trict.
The detailing of the geology and hydrology of Polk County pro-
vides the necessary data on many of Florida's phosphate deposits,
on a large part of the Green Swamp water management area, and
will contribute toward the further development of this area.


Respectfully submitted,
Robert O. Vernon, Director
Division of Geology



















































Completed Manuscript received
August 16, 1966
Published for the Florida Geological Survey
By Rose Printing Company
Tallahassee
1966







CONTENTS
Page
Abstract ..--........------.. ......-......... ...-...-...-...--.......-.......-.....................--- .... 1
Introduction ----........ ...... .....-.......-..... ....-..- ..----- .........-................................ 2
Purpose and scope of investigation ......-.............---..-.....-..---...............-.. 2
Previous investigations ...................--.....--....---- ...----- .. .....-..-...-- ....-..-... 3
Methods of investigation -....-......-----------...-...-..--...--------------.............. 4
Well-numbering system -----------------......................... ..- ..................... 6
Acknowledgements ........-....-.-----...... ....-......-.......-- ...------...----. ...-... 7
Geography --....------......-..-...........--- ........-- ..---- ............--..........--.... ....-..-...-....... 7
Location ....................................................................----- ........... ...........---- 7
Topography ...................-...... -------.......................--........................... ........ ..- 9
Climate .....--------------------.--.......... ....... ----------------.......... ..................................... 11i
Transportation .....--.........................-. ....-.................................. 12
Agriculture ............. .............................................................. ........................ 13
Agriculture ------------------------------------- ---------------------------------------- 13
M mineral resources ............-..-................--------... .. .. ............ .....--- ..- 13
Industry ------------------------------------------------------------------------ --------- 14
GeologIndustry ..y- -- ....--.-.- .. ....... .......................... .............................. .. 14

Stratigraphy ..................- ..........-..................... ...... ........................... .... 14
Eocene Series ----...--..........---------------- ------.. .. ..........---..-- 20
Oldsmar Limestone -.......--..---........--------------.. --......-....-- 20
Lake City Limestone --------.. --.... ----.......-- ---.------------....-- ----- 28
Avon Park Limestone .-..-.. ........---....-. ........-..--- --....----- 30
Ocala Group ...--.....................----------- ....-- ...-- ...-......---..--- 33
Inglis Formation ---........--......--.......-- ..-- ...- ------.-----..... 33
Williston Formation ...-----------... --..--....-. ... .....--....-...-------..--- 35
Crystal River Formation -...-...-....-.....-...--....-- .....----..------ 35
Oligocene Series .-...-..................-------------- .........------------ 38
Suwannee Limestone -.....---.........-- .............----- ..........--------- 38
Miocene Series -..................... ---..........-..--------------- ---------.------ 39
Tampa Formation ........-................. .............----- ............--------- 40
Hawthorn Formation .....-----.......--.........---- .......------ 45
Undifferentiated plastic deposits -------................ -- -...--.............. 46
Phosphate deposits -----...----... .....--- ..-.....-- .... .------..----- 47
Coarse plastic deposits .-..........------ ..--...----- ------.--.------. 47
Structure ----.......-----------....-..-.......--. .... .....................------------.. -- 48
History of structural movements ........-...........----..............---..---- 51
Solution features .....--........-..-....---------- --------- ---- 52
Cavities ..-----------................ -----------................---------- 62
Sinkholes ..................------ .......--....--- ..-- ..-- ......------- ---------------. 65
Hydrology .--------..--...-......--..--------..--- ..------------------ ------------- 69
Surface water ..-..-..............-...... ---- ---- ---------------------- 70
Streams ........---------..............-- .-- ------- ------------- --------------------70
Lakes -.---....--...........---..-....---. -----.--- ------------------------------ 72
Evapotranspiration ...............----......--- ....-.............. ........----- .--------- 76
Ground water ..-..........--- ..... ---------- ------------------------- 77
Occurrence ........------..------------- --------------------------- 77
Nonartesian aquifer ........ ----.--- ----------------------------------------- 78
Characteristics .....--.......-..---.....-....--- ......-... -------- ------------- 78
Water-level fluctuations ......----.......-........-------.. --------------- 79







CONTENTS Page
Uppermost artesian aquifer -......... --------..... .........-...--................- 8
Secondary artesian aquifer -..- .. ... ........------------....-........-... 83
Characteristics ...........-..... ....... ... ............................ 83
The piezometric surface -----..-..-....-------..........-.. ........... 85
Areas of artesian flow -.......--....-----------... --..-----............ 88
Water-level fluctuations ........-------.....-..-..................- 89
Floridan aquifer -...-..--... -. ------.......... -. ..- .. ----.......-- .......... 89
Characteristics ------.. -.....----.... -..-.. -- ........-..-....-..... ... 89
The piezometric surface .----- -------........--- ------............ 91
Areas of artesian flow ---.....-- ...---............---.......-- ... 100
Water-level fluctuations --- -- -----........... ........................ 100
Water-level history ..--....-- ..--..... --... ---- ..... ...-- -............ 102
Hydraulics .--.--------...... -.......-----. --. ----------------...---........-...- 105
Specific capacity of wells ...- ---.. .. ............ .................... 105
Vertical movement of water -..- ...........--- -...--...- -................... 112
Pumping tests ..--..........-- .......... ..--............-- ...........-- -- .-----. ....-... 112
Hydrologic properties of selected limestone core samples --................ 115
Recharge -------.--------..---.---.-------...........-..... ----------............ 116
Nonartesian aquifer ----... --....... --------....----........ ........... 116
Uppermost artesian aquifer ..~------------..............--.. ---- 117
Limestone aquifers --...-..----.---. .------------.......... --- ---. 117
Secondary artesian aquifer ...........-...- .......-..........-.....--. 120
Floridan aquifer ...... ......... ---- -------........ .. ......--.... ........... 121
Quality of water ........... -----............---.. ---------129
Chemical constituents ------- ---------------....... ......-----..... -.... 129
Change of chemical quality with time ....-..........--..--..-- ..--.............. 133
Change in chemical quality with depth ............-----....---... .........-- ....- 133
Water temperature .. --.--..--..-----....-... --..-....... .... -- 134
Summary of chemical quality .................. ...---- ..-- ..--..--.--. 135
Water use -. ..-.-..................------.-.. -- ---------- 136
Public supply .- ....--------- ..-- ................--- ..---- ...-..136
Domestic supply .- ....- ---....... -... ---.-------------...-...-..-..-..-... 138
Industrial supply ------..-..---...- ..----------... -. -------- 138
Irrigation supply .--- .--......---------- --- .......-............--........ 139
Miscellaneous supplies -----......- .. ...- --------- -............... ....... 140
Summary of water use ---.-- ---------........~ .........-----......--.--..-. 141
Special problems .. --~.... ..........-----....---- --.........------ 141
Lake Parker ----....--.........-..-- ..-........-- ---- ------------ 141
History and nature of problem .-...-......-........-......-.....-- ..------ 141
W ater budget .................... ...-. .... ....-- ..- ..............----..------- -... 147
Conclusions ---.......-... ..--------.-...........--...... --------151
Scott Lake .........-..----....--... -....---.------...............-.----- 153
History and nature of the problem ....--------....--..--............. ...----- .. 153
W ater budget .....-.....-- -- -----..-..... .-........-.. -....................-.....-..--- ---- 158
Conclusions ..-..-..........--..--- .....----------- --- .--......------ 161
Summary .....-----.......-- .--.--....... .....-........... ....................................-------- --- 161
References -...- ...--....-...- -.. --.. ....-.......-- -- ......--------.165







ILLUSTRATIONS

Figure Page
1 Map of Florida showing the location of Polk County and the well-
numbering system .---.......---- .......-- ...-----...... ..............--- ..........-- 6
2 Topographic map showing major physiographic features ............... 8
3 Graph showing total annual rainfall at Lakeland, 1915-59 ---......- 11
4 Map showing the location of selected wells --..---...... Facing page 14
5 Geologic map of the pre-Miocene formations ----..........----............ 34
6 Geologic sections along lines A-A' and B-B'. Sections located on
Figure 5 ....---------....-----... -------.... ----------........--..--..-- .. 43
7 Geologic sections along lines C-C' and D-D'. Sections located on
Figure 5 ....---.....--......----......- ...-..-- .... .......-------.... ........... ........-- 44
8 Structure-contour map on top of the Inglis Formation --...--....-------.. 50
9 Map showing the location of wells penetrating solution features in
the limestone ..----------------- ----.. .... ------................ .......-- ...-- .. 63
10 Map showing location of recent sinkhole collapses -------...... ---........ -- 66
11 Photographs of recent sinkhole collapses ...--...... ..........................-- 68
12 Hydrographs of water levels in Lakes Wire, Hollingsworth, Deeson,
Crystal, and Bonny near Lakeland and rainfall at Lakeland,
1954-59 ...------......-- ............ .... ...------.. ----.......... ............ 74
13 Water-table contour of the Lake Parker area, June 25-30, 1956 .-... 80
14 Map showing water levels in selected wells penetrating the non-
artesian aquifer, (October 29, 1959 to February 4, 1960) .............. 81
15 Hydrograph showing fluctuations of the water table in a well near
Haines City (810-136-2) in the nonartesian aquifer --................ 82
16 Hydrographs showing fluctuations of the piezometric surface in a
well near Lakeland (803-153-18) and a well near Frostproof (744-
131-1) in the secondary artesian aquifer ------------............................ 85
17 Piezometric-contour map of the secondary artesian aquifer of Lake
Parker area (June 1956) -..-...-...--......--................------------------- 86
18 Piezometric-contour map of the secondary artesian aquifer in Lake
Parker area (October 1959 to February 1960) ---........--------... ...------ 87
19 Piezometric-contour map of the secondary artesian aquifer (Octo-
ber 1959 to February 1960) ---------.. ---................................-....----- 88
20 Piezometric-contour map of the Floridan aquifer (October 1959 to
February 1960) --.....................---- ..------...... ---.....--- Facing page 90
21 Piezometric-contour map of the Floridan aquifer in northwest Polk
County (June 1956) -....--.......------...... ----------..--------- 98
22 Piezometric-contour map of the Floridan aquifer in Lake Parker
area (October 1959 to February 1960) ..............----..-..-........--.... 99
23 Hydrographs of fluctuations of piezometric surface in a well near
Lakeland (759-158-1) and a well near Davenport (810-136-1) in
the Floridan aquifer ......---------.....--............. -.. ..-------------- -----....... ......--- 101
24 Map of peninsular Florida showing the piezometric surface of the
Floridan aquifer in 1944 .....-----.....................----------.... ---------.. 123
25 Piezometric-contour map of the Floridan aquifer at Lakeland (No-
vember 20, 1959) -------... ----..................----.............------ 128
26 Map showing hardness of water in selected wells in the Floridan
aquifer ................-------------------------.... ------------------ 132






27 Map showing water temperatures in selected wells in the Floridan
aquifer ....-------.-----------..--. --------..- ...-..................--............ 134
28 Graph showing total annual municipal pumpage by City of Lake-
land, 1928-59 .. -...................................................................................- 117
29 Log of sediments penetrated in test hole 805-156-A, in Lake Parker. 144
30 Hydographs of water levels in Lake Parker and in wells 803-
154-10 and 806-154-1, 1954-56 .................................... ...... .............. ... 145
31 Hydrographs of water levels in Lake Parker and in wells 805-155-1,
2, and 3, 1956-59 .......-.......-- .-.. ----...... .... ................. .............-...- 146
32 Hydrographs of water levels in Lake Parker and in wells 805-
155-1, 2, and 3, during 1958 .. .-........ .. ................--.................... 147
33 Hydrographs of water levels in Scott Lake and in wells 758-156-5,
757-155-3, and 757-155-6, 1954-60 ..... ...... ........ ....-.......-....... ........-... 154
34 Hydrographs of water levels in wells in the nonartesian aquifer in
the Scott Lake area ...--. --........- ..-- ......--- ....-- ......--- ...-....--....-------- 155
35 Map showing water levels and other features of the Scott Lake
area, July 1956 .........-------- ........---------.....--......---......---- ...---- .....-- 156
36 Map showing water levels and other features of the Scott Lake
area, October 1959-February 1960 .......-.......----....-..-............------- -- ... 157



TABLES
Table
1 Mean monthly temperature and rainfall at Lakeland, Florida for
period 1915 to 1959 .......------ --.. ....-.................- ..... .. ..... .----- 12
2 Total annual rainfall at U.S. Weather Bureau stations in Polk
County, 1954-59 ......................................................---...-...... .....----........... 12
3 Geologic data from wells in Polk County .. .... -----....................-..-- 16
4 Solutional features penetrated by wells in Polk County ...............-..-- 54
5 Records of the occurrence of recent sinkholes in Polk County .......... 67
6 Annual runoff by drainage basins, 1954-59 -...-....--... ....-----.............. 71
7 Water levels observed during drilling operations ..........--.....-- ...-..-.-- 92
8 Net change in water levels in wells in the Floridan aquifer, 1934-59 103
9 Specific capacities of selected wells in Polk County ---..--..-.......-..-.. 104
10 Specific capacities of wells in Polk County ..........---------...... .............. 106
11 Hydrologic properties of limestone core samples from well 805-
154-8 ............ ...--- -- .......... ..- .. -.....-..----- ......-.... 113
12 Range of concentration of chemical constituents in waters of Polk
County _.0............ -.. _.. .. ................................. 1
13 Annual metered pumpage by municipal systems in Polk County,
1954-59 -...--.. --...............----------- -...-..- -..--.....-...--...- .....--........-- ........-------- 1 6
14 Stream-flow measurements in the vicinity of Lake Parker and Sad-
dle Creek .................---- -..--...-. -- --------- --...........--...........-..-.. 148






GROUND-WATER RESOURCES OF
POLK COUNTY, FLORIDA

By
Herbert G. Stewart, Jr.

ABSTRACT
Polk County, Florida is located approximately in the center of
the Florida peninsula, and is an area which requires large quanti-
ties of water for industry, agriculture, and municipalities. Nearly
all water supplies in the county are obtained from ground-water
sources. Domestic and small irrigation supplies are obtained from
limestones of the Hawthorn Formation of Miocene age, and to a
lesser degree from unconsolidated plastic deposits which range in
age from middle Miocene to Recent. Large water supplies are ob-
tained from the Floridan aquifer which includes limestones
ranging in age from middle Eocene to middle Miocene. Geologic
studies near Lakeland show that the Avon Park Limestone is the
lowest unit of the Floridan aquifer, and that there has been no
circulation of ground water in the underlying formations.
The southern end of the Ocala uplift extends into Polk County
and the highest piezometric levels in the Floridan aquifer occur
in the county. As a result of the Ocala uplift the rocks of the
Floridan aquifer have been highly fractured which has resulted
in solutional development of the limestone and extensive cavern
systems. The fracturing has also permitted the free circulation
of water between all units of the aquifer.
Water recharges the Floridan aquifer principally by down-
ward percolation from surficial sands and through the intervening
units to the Floridan aquifer. Only a few inches of rainfall per
year enters the aquifer as recharge in the county. Water budget
analyses for two lakes near Lakeland, during the first 6 months
of 1956, show that the lakes recharged the underlying limestone
:aquifers. Lake Parker recharged water to the Floridan aquifer at
rate of about 2.5 inches per month and Scott Lake recharged
water to the limestones of the Hawthorn Formation at a rate of
About 5 inches per month. Data suggest that other lakes in the
-ounty may also recharge the aquifers at slow rates.
During 1959, approximately 80 billion gallons of ground water
,ere pumped from the aquifers in the county. During the same
.:ear approximately 120 billion gallons were determined to re-





FLORIDA GEOLOGICAL SURVEY


charge the limestone aquifers within the county. The excess o'
about 40 billion gallons moves through the aquifers into adjacent
counties. The potential availability of ground water in the county
can be increased by using more ground water which in turn
creates increased storage in the aquifers.



INTRODUCTION

PURPOSE AND SCOPE OF INVESTIGATION

The investigation upon which this report is based was begun
in April 1954 by the U.S. Geological Survey in cooperation with
the Florida Geological Survey and the Board of County Commis-
sioners of Polk County. Preparation of the final phases of the
manuscript was effected with the cooperation of the Southwest
Florida Water Management District. The general purpose of the
investigation was to provide basic information to assist in the in-
telligent development of the water resources of Polk County. The
investigation was specifically designed to (1) determine the re-
lationships between some of the lakes in the county and the
ground-water aquifers, including the effects of large withdrawals
of ground water on lake levels; (2) determine the mechanics and
quantities of recharge to the principal ground-water aquifers and
to locate areas in which such recharge is occurring; and (3) de-
termine amounts of water being used and to estimate the total
amount available from the principal aquifers.
This report presents general information on the geology and
hydrology of the county and specific information on two lake
basins located in the northwestern part of the county. The rela-
tionship of the many lakes in this area to the ground-water supply
and the effects of large withdrawals of ground water on both
ground-water and surface-water levels are matters of great in-
terest in the county. The complexity of the hydrology of the area
made it necessary to study the geology in considerable detail.
A preliminary report of the investigation was prepared by the
author (1959) and presented detailed information on specific
problems relative to two lakes near Lakeland.
This report constitutes the final interpretative report of the
investigation. A companion report of basic data was also prepared
(Stewart, 1963) and contains well data, chemical analyses, water-






REPORT OF INVESTIGATION NO. 44


level measurements and lake-stage measurements, and other data
g-athered during the course of the investigation.

PREVIOUS INVESTIGATIONS
Some geologic and hydrologic work has been done in Polk
County as part of regional or statewide investigations. Most of
this work has been done by the U.S. Geological Survey and the
Florida Geological Survey.
Cooke (1945), Vernon (1951), and Parker, Ferguson, Love,
and others (1955) described the general geology of central Florida
and made many references to Polk County. Cole (1941, 1945),
Mansfield (1942), Cathcart and Davidson (1952), Davidson
(1952a, 1952b), Cathcart and others (1953), Carr and Alverson
(1953, 1959), Puri (1953b, 1957), Bergendahl (1956), Cathcart
and McGreevy (1959), Ketner and McGreevy (1959), Altschuler,
Clark, and Young (1958), and Altschuler and Young (1960) dis-
cussed the geology of one or more of the formations which are
present in the county. Fenneman (1938), Cooke (1939), MacNeil
(1950), and White (1958) discussed the topographic features of
central Florida, and their origin and development.
Sellards (1908), Sellards and Gunter (1913, p. 262-264), Mat-
son and Sanford (1913, p. 388-390), and Gunter and Ponton
(1931) prepared early discussions and data concerning ground
water in Polk and other counties of central Florida. Stringfield
(1935, 1936, p. 148, 172-173, 186) investigated ground water in
the Florida peninsula and presented data from Polk County. An
important result of his investigation was a piezometric map of
the principal artesian aquifer of peninsular Florida (the Floridan
aquifer in this report) which shows areas of recharge to and dis-
charge from the aquifer in Polk County. The map was expanded
to include most of northwestern Florida and part of southern
(eorgia by the work of M. A. Warren, V. T. Stringfield, and
F. Westendick', and was shown by Cooper (1944, fig. 2), Warren
(1944, fig. 3), and Unklesbay (1944, fig. 5). Cooper (1944),
Stringfield and Cooper (1951a), and Cooper, Kenner, and Brown
(1953) discussed the ground water of Florida and referred to re-
t charge of the principal artesian aquifer in Polk County. Papers by
3'erguson, Lingham, Love, and Vernon (1947), and Stringfield
and Cooper (1951b) described the geologic and hydrologic fea-
1 Oral communication, H. H. Cooper, Jr., U.S. Geological Survey, May 4,
:961.






FLORIDA GEOLOGICAL SURVEY


tures of springs in Florida and presented flow measurements and
other data for some springs. Peek (1951) discussed the cessation
of flow of Kissengen Spring in Polk County.
Collins and Howard (1928), Black and Brown (1951), and
Wander and Reitz (1951) discussed the chemical quality of ground
and surface water in Polk County and other parts of Florida, and
presented many analyses.

METHODS OF INVESTIGATION
Field work began May 1, 1954 with an inventory of water
supplies in the northwestern part of the county. Later the inven-
tory was extended to include the remainder of the county. Infor-
mation on the depth, depth and diameter of casing, water level,
yield, type of pump, use, and quality of the water was obtained
for more than 1,300 wells.
During the inventory, specific wells were selected for the ob-
servation of water-level fluctuations. Water levels were measured
periodically in most of the observation wells, however, continuous
water-level recording instruments were installed on 13 of them.
The levels of several lakes in the northwestern part of the county
also were measured periodically and recording gages were in-
stalled on Lake Parker and Scott Lake, in the Lakeland area.
Current-meter and temperature logs were obtained from 12
wells in the county.
Samples of water were collected from wells and surface sources
for chemical analysis. Composite water samples were collected
from wells being pumped. Water samples were also collected from
bailers, both during drilling operations and after completion of
wells.
Consolidated rocks were found exposed at land surface in small
areas of extreme northwestern Polk and adjacent counties. These
out-crops were examined, mapped, and samples collected in recon-
naissance with Mr. E. W. Bishop, Florida Geological Survey. Dur-
ing mining operations the phosphatic limestones of the Hawthorn
Formation were briefly exposed in the bottoms of some of th,
mine pits in the Lakeland area, and these were studied and de-
scribed whenever possible. Unconsolidated deposits, below the
loose surficial sands, were found exposed in road-cuts, borrow-piti
in the ridge areas along the newer highways, and in phosphate
mine pits and these deposits were briefly studied and described.
Studies of rock cuttings were made during well-drilling opera-






REPORT OF INVESTIGATION No. 44


tin s. Samples from about 250 wells in Polk County are presently
flied at the Florida Geological Survey, most of which were col-
lected and donated by the local well drillers. Cuttings from 25
deep wells, 14 shallow wells, and 4 test holes were collected and
examined during the investigation. Eleven other sets of samples
from wells in the county were collected and logged by other geol-
ogists of the State and Federal Surveys. Most of these wells were
drilled by the cable-tool method. A few wells were started and the
casing installed by the rotary method, and the open-hole portions
of the wells completed and samples collected by the cable-tool
method.
Two deep exploratory wells drilled near Lakeland by private
industry during 1959-60 made an important contribution to
geologic and hydrologic knowledge in this county. The first well,
805-154-8, five miles northeast of Lakeland, was continuously
cored from 58 feet below land surface to a total depth of 1,479
feet with more than 95 percent core recovery. The second, 801-200-
3, three miles southwest of Lakeland, was cored from near the top
of the thick dolomite interval of the Avon Park Limestone (652
feet below land surface) to a total depth of 1,846 feet. The forma-
tions penetrated by the wells include formations deeper than those
normally penetrated by water wells in the county.
The cores from these two wells provide the most complete and
accurate record obtainable from Polk County of the rock forma-
tions penetrated and together with the electric and gamma-ray
logs from the two wells, are used as basic control for all geologic
studies in this report. Rock cuttings and electric logs from other
wells studied during this investigation are used as second-order
control; other sets of well samples and electric logs in the files of
the Florida Geological Survey are used as third-order control;
electric logs of wells from which no samples are available are
used as fourth-order control.
Additional geologic information was obtained from 65 electric
logs of wells made with a single-electrode logger and from 61
gamma-ray logs. For geologic correlation 29 electric logs and 30
gimma-ray logs were made in wells from which rock cuttings
w ;re available for study. The electric logs served as the basis for
m ich of the interpretation of geologic structure in this report. The
gi mma-ray logs were less useful as a geologic tool, but served as an
ai xillary source of data with reference to pebble-phosphate de-
P: sits and the Miocene limestones. Drillers and well owners have
a' o given to the State or Federal Geological Surveys 146 descrip-






6 FLORIDA GEOLOGICAL SURVEY

tive logs of wells from which cuttings were not collected. These
descriptive logs have been of value in the interpretation of ground-
water conditions, general lithology, and geologic structure.


WELL-NUMBERING SYSTEM

The well-numbering system used in this report is based on
latitude and longitude coordinates. Figure 1 shows the well-
numbering system used in this investigation. The well number was
assigned by first locating each well on a map that is divided into
1-minute quadrangles of latitude and longitude, then numbering
each well in a quadrangle in the order of inventory. The well num-
ber is a composite of three numbers separated by hyphens: The
first number is composed of the last digit of the degree and the

Cet ot "gvuel *,l#% of the Green l. CEngfonl, prim mrito.an



,, E 0-I- ..--- -

\4 IV,.. ....





3,-o3 1 ISf or






... .. .. Lolls
tot0t0 of .











Figure 1. Miap of Florida showing the location of Polk County and the
well-numbering. ap of Florida showing the location of Polk County and thesystem.
well-numbering system.






REPORT OF INVESTIGATION NO. 44


t\ -o digits of the minute of the line of latitude on the south side
of a 1-minute quadrangle; the second number is composed of the
last digit of the degree and the two digits of the minute of the line
of longitude on the east side of a 1-minute quadrangle; and the
third number gives the order in which the well was inventoried in
the quadrangle. For example, well 826-131-3 is the third well in-
ventoried in the 1-minute quadrangle north of 28026' north lati-
tude and west of 810311 west longitude. By means of this system,
wells referred to by number in the text can be located on the vari-
ous plates and illustrations of this report.
The same system is used in numbering test holes, exposed sec-
tions, sampling stations, and points of various observations that
were collected or described, except that consecutive letters of the
alphabet are used instead of consecutive numbers. For example,
805-156-A was a test hole. The test holes were filled and aban-
doned immediately after drilling, and therefore are distinguished
from wells.



ACKNOWLEDGMENTS
The investigation was greatly facilitated by the interest, co-
operation, and assistance of city, county, and industrial officials,
residents, and landowners. Well drillers in the area have repeat-
edly made their time, experience, and records available to the
author. Appreciation is here expressed to all of these people.
Grateful acknowledgment is here made to E. W. Bishop, geolo-
gist, Florida Geological Survey, and F. W. Meyer, geophysicist,
U.S. Geological Survey, for the many beneficial discussions and
the exchange of ideas and concepts during the investigation.


GEOGRAPHY
LOCATION
Polk County comprises an area of about 1,860 square miles in
t! e central part of peninsular Florida. (See figure 2.) The county
'.as established February 8, 1861, by separation from what was
t! en Hillsborough County. Hetherington (1928, p. 14) records an
a count of Mr. B. F. Blount that indicates that the population in
C Atober 1851, of what is now Polk County, totaled about 20 fami-






FLORIDA GEOLOGICAL SURVEY


Figure 2. Topographic map showing major physiographic features.

lies, a garrison of soldiers, and some Seminole Indians. Since that
time the population has increased steadily.
The following population figures for the county were taken
from published reports of the U.S. Bureau of Census:
1890 7,905
1900 12,472
1910 24,148
1920 38,661
1930 72,291
1940 86,665
1950 123,997
1960 195,139
The population is concentrated in the cities and towns along the
ridges in the interior of the county. Several hundred square miles
in the northern part of the county and much of the area east cf
the Lake Wales ridge is sparsely populated. The southern part cf
the county is also sparsely populated. Generally, these areas ars






REPORT OF INVESTIGATION No. 44


poorly-drained grasslands and flatwoods, relatively low and flat,
and are largely devoted to cattle ranching. During the period of
this investigation many isolated, well-drained hills and low ridges
within the northern and southern areas were cleared and citrus
trees were planted.
The three major ridges and much of the well-drained inter-
ridge areas are devoted to citrus groves. Numerous small truck-
farms are also found in the inter-ridge areas. Vast areas in the
southwestern part of the county have been mined for pebble-
phosphate. Much of the mined-out area has not been improved and
now stands as rugged spoil piles.

TOPOGRAPHY
Polk County is part of the Central Highlands physiographic
division of Cooke (1939, p. 14, fig. 3), the Limesink and Lake Re-
gions of the Floridan Section of the Atlantic Coastal Plain prov-
ince of Fenneman (1938, p. 46-65, and the Atlantic Coastal Plain-
ground-water province of Meinzer (1923a, p. 309-314).
The county is part of the highland area that trends along the
longitudinal axis of the Florida peninsula. The major topographic
features of the county are three long, irregular, north-south trend-
ing ridges which are separated and bounded by relatively flat low-
land. These and other topographic features are shown in figure 2.
The easternmost of the ridges extends from the common corner of
Polk, Osceola, Orange, and Lake Counties approximately south
through Haines City, Lake Wales, and Frostproof, and into the
southern part of Highlands County. MacNeil (1950, p. 101) has
referred to the eastern ridge as the Lake Wales ridge, and White
(1958, p. 10) also uses this name. This is the highest, longest, and
narrowest of the three ridges in the county. Altitudes on the crest
of the ridge range from 150 to 305 feet above msl (mean sea level)
and are highest at Lake Wales and Babson Park.
The central, or Winter Haven ridge (White, op. cit.), begins
abruptly at Polk City, and continues south-southeastward through
Auburndale and along the east side of the Peace River valley to
F'. Meade. It appears to merge with the Lake Wales ridge about
4 miles southwest of Frostproof. This ridge is actually a zone of
snall ridge-remnants approximately 8 miles wide. Between Bar-
tc w and Ft. Meade this ridge becomes a much more massive unit,
b oader and higher than the northern unit. Altitudes along the
c est of the northern unit range from 150 to 200 feet msl, and






FLORIDA GEOLOGICAL SURVEY


much of the southern unit ranges from 200 to 230 feet msl.
The westernmost ridge, or the Lakeland ridge (White, 19.58,
op. cit.), begins abruptly about 10 miles northwest of Lakeland
and extends south-southeastward through Lakeland and between
Bartow and Mulberry, to the vicinity of Ft. Meade. Altitudes along
the crest of the ridge range from 150 to 270 feet msl, and much
of it lies above 200 feet msl. The Lakeland ridge is more continu-
ous and narrow than the Winter Haven ridge. The Lakeland and
Winter Haven ridges appear to trend slightly more north-west-
southeast than the Lake Wales ridge.
All of the ridges are being lowered and dissected by sinkholes.
The Lake Wales ridge has been transected by sinks in the Frost-
proof area, and many other saddles in the ridge are approaching
complete transaction.
The northern part of the Winter Haven ridge has been thor-
oughly dissected by sinks. However, the massive southern unit re-
tains a relatively juvenile linearity on the western flank, and is
being slowly dissected on the lower parts of the eastern flank.
Transection of the two units of this ridge has been complete in a
broad area along Florida Highway 60, north of Alturas. The Lake-
land ridge is being dissected much more slowly than the other two,
though large non-lake sinks appear to be more numerous in this
ridge than in the others.
The northern part of the county, west of the Lake Wales ridge
and north of the other two ridges, is a broad poorly-drained flat-
land that slopes northwestward from about 140 feet msl to about
90 feet msl. It is an area of pine flatwoods, cypress swamps (called
domes), and intervening grasslands.
On the eastern flank of the Lake Wales ridge there are two
large areas of dune-covered terraces and sand hills, one located
southeast of the city of Lake Wales and another north of Daven-
port. East of these is the broad, slightly rolling to flat, marshy
lowland of the Kissimmee River.
Another broad, flat to rolling, lowland exists across the south-
ern part of the county, west of the Lake Wales ridge and south of
the other ridges. Much of this area is poorly-drained pine flat-
woods. The interridge areas are partly rolling lower land, aid
partly low flatwoods and marshes.
Maximum local topographic relief in the county is 219 feet in
the Lake Lenore basin, southeast of Babson Park. Total relief in
the county is 255 feet (from 50 to 305 feet msl).
Surface drainage is poorly developed in the county. On the fl&t-






REPORT OF INVESTIGATION NO. 44


lands there are hundreds of perennial and ephemeral swamps and
basins of interior drainage. In the ridge areas, basins of interior
drainage are even greater in number, depth, and diameter than on
the lower flatlands. In both types of topography some of the basins
of interior drainage (sinkholes) contain lakes.

CLIMATE
All climatic data used in this report are taken from the pub-
lished records of the U.S. Weather Bureau. The data from the
Lakeland station are believed to be generally representative of the
county.
The area has a humid subtropical climate and only two pro-
nounced seasons-winter and summer. The average annual tem-
perature is 720F, and the average monthly temperatures range
from 620F in December and January to 82F in August. The av-
erage annual rainfall is 51.43 inches, about three-fifths of which
occurs from June through September. Most of the rainfall comes
from thunderstorms, which average about a hundred per year.
Total annual rainfall at Lakeland, for the period of record, is
shown graphically in figure 3. The mean monthly temperature and
rainfall through 1959 are shown in table 1.
Total annual rainfall at the Weather Bureau stations in the
county during the period of this investigation is given in table 2.


Figure 3. Graph showing total annual rainfall at Lakeland, 1915-59.







FLORIDA GEOLOGICAL SURVEY


It is to be noted that the rainfall at Lakeland, Bartow, and Lake
Alfred Experiment Stations in 1959 established record highs for
these stations. The Mountain Lake station lacked 31/2 inches that
year of equaling its record high. The second lowest rainfall of rec.
ord for Lakeland (36.30 inches) occurred in 1954, and the lowest
rainfall of record at Lake Alfred in 1955. Table 2 clearly indicates
the great difference in local precipitation in this area. The differ-
ence between highest and lowest total annual rainfall for the sta-
tions shown exceeded 20 inches in 1957 and 1958.

TABLE 1. Mean monthly temperature and rainfall at Lakeland, Florida', for
period 1915 to 1959.

Temperature Rainfall
Month (F) (inches)
January 62.4 2.21
February 03.0 2.47
March 67.3 3.69
April 72.0 3.24
May 77.0 4.43
June 80.4 7.38
July 81.6 8.02
August 82.0 7.30
September 80.3 6.42
October 74.7 2.88
November 67.2 1.72
December 63.0 1.97
Annual 72.7 51.79

I U.S. Weather Bureau. Local Climatological Data with comparative data,
Lakeland, Florida for period 1915 to 1959.


TABLE 2. Total annual rainfall at U.S. Weather Bureau stations in
Polk County, 1954-59.


Station
Bartow
Lake Alfred Exper. Sta.
Lakeland
Mountain Lake (at Lake Wales)
Winter tavun
Babson Park


1954 1955 1956 1957


Mean
1958 1959 nn
1058 1050 annuaPl


51.19 41.41 46.34 73.72 61.82 83.44 -54.12
38.27 35.66 44.40 57.99 40.89 o76.57 51.17
36.30 44.08 45.12 62.38 41.74 70.24 51.43
46.05 43.98 41.35 58.21 55.09 71.42 52.70
38.68 38.78 44.55 66.07 52.73 73.28 1
- 36.54 51.14 57.50 66.97 I


1 U.S. Weather Bureau, "Climatological Data-Florida-Annual Summary" 1954 through 1959
s Not computed-less than 20 years record available
a From U.S. Weather Bureau long-term records
e estimated



TRANSPORTATION

The principal highways in the county are U.S. Highways 93,
27, and 17, which are north-south routes, and U.S. Highway 92
and Florida Highway 60, which are east-west routes. These ale






REPORT OF INVESTIGATION NO. 44


augmented by a network of additional state and county roads.
However, in the less populated northern and eastern parts of the
county there are only a few graded roads.
Most of the towns and cities of the county are served by main
lines of the Seaboard Air Line or Atlantic Coast Line Railroads.
In general, the area is poorly served by direct air service; only
Lakeland has regularly scheduled flights.

AGRICULTURE
Various types of agriculture play an important part in the
economy of the area, and many are important water users. The
most important type of agriculture is the growing of citrus fruits,
principally oranges and grapefruit. Cattle ranching is also an im-
portant part of agriculture. Truck-farming, lumber, and other ag-
ricultural pursuits are of less importance in the economy of the
county.
In the 1954 Agricultural Census (U.S. Bur. Census, 1957, p.
149), Polk County ranked first in the State in the production of
citrus fruits, having 8,012,894 orange, grapefruit, and lemon trees.
The county is also a leader in the production of the less common
citrus fruits, such as limes, tangeloes, and kumquats. Normally, the
citrus groves are irrigated one or more times a year as required.
Locally the growing and marketing of truck-farm crops such
as strawberries, peppers, beans, squash, and other vegetables is
important. The truck farms are relatively small, and normally sev-
eral different crops are grown in rotation during a single year.
These crops are generally irrigated heavily and often.
In 1954 Polk County ranked first in the State in the produc-
tion of cattle (U.S. Bur. Census, 1957, p. 107) with a total of
121,773 head. Ranches are usually large, and are located on the
flatlands in the peripheral areas of the county.

MINERAL RESOURCES
At present eight companies are actively engaged in open-pit
mining of pebble-phosphate in the county. Production in 1959 to-
taled 10.2 million long tons of phosphtae rock2. The mining process
ut lizes large quantities of water; however, extensive storage, set-
tliig, and recirculation practices reduce the amount withdrawn
SPersonal communication, Mr. E. W. Bishop, Florida Geological Survey,
November 7, 1960.





FLORIDA GEOLOGICAL SURVEY


from ground-water aquifers.
More than ten companies were mining (dredging) silica sand
from the unconsolidated deposits in the county in 1960. Five of
these companies are located in the Lake Wales ridge, where the
thickest deposits are found. Other companies were operating in or
near Mulberry, Bartow, Ft. Meade, Waverly, and Winter Haven.
Sand and gravel production totaled 3.3 million short tons in 1959
(U.S. Bur. Mines, 1959, table 5). Most of the water used in this
production is readily obtained from the excavations, and does not
represent significant industrial consumption of ground-water sup-
plies.
Limestone has not been mined in the county due to the thick-
ness of the unconsolidated overburden, low purity of the upper-
most limestone in some areas, and high ground-water levels. How-
ever, a relatively large, previously unmapped area of silicified
limestone, cropping out in the northwestern part of Polk County
and southern parts of adjacent counties, which may become im-
portant to the economy of the county, is discussed later in this
report. Silica replacement of the limestone surface and artesian
ground-water conditions present problems in the newly mapped
area, but an economic potential is clearly present. In 1960, agricul-
tural limestone was being obtained from the Ocala-Brooksville area
to the north or from western Manatee County to the southwest.

INDUSTRY
One of the major industries in the county is the packing, can-
ning. and concentrating of citrus fruits and juices. Another, and
less prominent, allied industry is the production of cattle feed from
the peelings of citrus fruit. Juice concentrate plants are among,
the large consumers of ground water in the county.
The refining of pebble-phosphate and the preparation of com-
mercial fertilizers is a very large and important industry of the
area. Polk County ranks first in the State in the production of
both the refined triple-super phosphate and fertilizers. These
plants use very large quantities of ground water.

GEOLOGY
STRATIGRAPHY
A knowledge of the geology of the rock formations is essential
in the evaluation of aquifers as sources of water. The texture ant






REPORT OF INVESTIGATION NO. 44


S,)mposition of the rocks affect the chemical composition of the
\ater contained and the rate of ground-water movement through
tnem. The thickness, areal extent, and fracturing of the various
rocks will also influence the rate of ground-water movement and
yield of wells. Structural deformation and chemical alteration also
affect the rate of movement through individual rock units and be-
tween units.
Vernon (1951), Cooke (1945), and many others have described
the rock units present in Polk County, their general relationships
and geologic history, the origin of the different unit names, and
the criteria for their identification. However, there has been no
previous work which describes the geology of the county in suffi-
cient detail to understand the hydrology of the rock units.
The areal extent of the various units has not been previously
established. The literature notes cavernous limestone in central
Florida but does not detail the occurrence nor adequately consider
the origin of these solution features which are so important to
ground-water movement. The work of Vernon (1951, pi. 2) sug-
gests the presence of extensive fracturing in the rocks of Polk
County which would also greatly influence the hydrology. The
existing literature does not define the thickness or depth of rocks
which contain fresh water. Thus, a considerable part of this in-
vestigation was devoted to geologic studies that were aimed at
providing more detailed information on hydrology.
All of the consolidated rocks of the county that are normally
penetrated by water wells are limestones or dolomitized limestones.
Over most of the county these are buried by phosphatic clays
which are in turn covered by a blanket of sand that constitutes
the surficial material. Consolidated rocks crop out in a few, rela-
tively small, areas in the northern part of the county. Most of the
geologic information for this report was obtained from rock cut-
tings taken from wells and by the interpretation of electric and
gamma-ray logs of wells. Figure 4 shows the location of wells in
Polk County.
Table 3 shows the depths to the tops of the various geologic
'ormations as determined during this investigation. Table 3 does
lot include a summary of open-file geologic logs of wells by the
*'lorida Geological Survey and which were used in the present
tudy. In the following paragraphs the rock formations penetrated
>y wells in this county are discussed from oldest to youngest.
The stratigraphic nomenclature used in this report conforms
o the usage of the Florida Geological Survey. It conforms also to








TABLE 3, Geologic data from wells in Polk County
Approximate depth to top of each formation given in feet Data source: D, driller's log; G, gamma-ray log;
below land surface: a, absent; c, cased off; e, estimated. S, samples; X, electric log.

APPROXIMATE DEPTH TO TOP OF FORMATION
FOS Hawthorn Ocala Group
USG8 well Altitude Formation Avon
well number of land (Uu.aotone Tamrp Suwannee Cry tal Park
number (W.) aurfaoe only) Formation Limestone River Williton Inglis Limetone Data ource Remarks


74210-2 ...
744.131-1
744-167-1 8852
746-184-1 6351

746-18-1 2304
745-168- ....
745-159-2
747-114-1 1726
747-132-1 4988
747.148-1 1062
747-1583 .
748-119-2 4288
749-149-1
751-156-3 4185
752-150-1 ....
752-150-2 3802
752-10-4 2431
753-128-1 4381


4190



-2765
2742

1441


4255
4684
4902


93
98
148
el85

103
187
e160
e61
202
115
180
100
120
173
e125
123
133
136

110
121
124
101
120
218
216
1l09
264
117
128
265
266
258
140


a
202
c219
140

50
o
112
185
250
@90
58
AB
c250
e52
085
05,
125
80
220


c!


o 382
282
o300 230
aT 230


230
a
250
a
a
e140
220
a
190
125

a?


,X
D, X
8


*275
@394
a
320
c198
277
a
210
245
205

240


5007
027

455
495
590
474
405


360T


1a a 190 210 300 350
92 124 a 146 309 333
o c l155 256 370 395
S c c236 250 382 407
o40 64 120 248 368 392
120 250 300 435 545 610
85 250 300
29 72 80
250 293 323 370 541 582
a a c55 203 824 330
c c 150 250 ...
150
S a c c c c519
140 200 290 425 565? 590
60 a 155 250? ...


630 D, 8
717 X
X
380 D, G..X
320 S X
010 D X
G X
524 G, X
5807 D S
X
...D. S
D. B
5207 8

440 D. 8
G, X
429 X
464 G, X
450 G, X
005 D, 8
D, S
X
658 X
375 D, G, X
G, X
G, X
6507 DD,
... D, S


el37 110 a 140 230 330 380 400 D, S


P-51
Tampa clay not presented
ln samples; no driller's log
available.










Tampa not evident in sam

Tamp not evident in samples
or riller's log.


FGS Wgi-714

P-67
Lare intervals between sam-
Tampa clay not evident in
samples or driller's log
do.


753-129-2
753-139-1
753-152-1
758-168-3
754-181-4
754-155-2
754-158-3
155-151-3
750-134-2.
757-162-1
757-153-2
757-155-
787-18-6
757-155-7
758-146-1
7b9-144-2


---








759-201-1 632
800-138-1
800-142-1 4551
800-148-2 864
800-146-1 3200
800-153-1
800-153-3 724
800-154-3
800-154-6 4775
800r159-1 3420
801138-2 4493
801-143-1
801-1544
801-154-8 4253



801-200-3 f2 core



802-139-2 5098
802-143-3 3807
802-144-2 5443
802-146-2 3851


802-149-4 3633
802-153 ..
802-151-10 ....
802-161-19
802-152-10 3422
802-157-16 4153
802-200-1 4737
803-137-1 1416
808-143-2 5353
803-145-2 2925
803-148-6 4050
808-148-7 4215
803-151-11 3772
803-153-3 ....
808-153-6 ....
803-153-24 3425


150
132
123
147
165
152
127
119
e124
e140
146
128
151
147
148


075
118
132
190?
a
89
c95
120
100
96

101
a?


0140
103
a
147
200
155
127
c110
136
130
106
@180
128
170?


c
222
123
a

260
246
217



192
270?


e135 18 83 129 214


120
145
el68
152


130
119
111
113
110
191
136
164
el13
155
133
141
113
128
127
124


100 a 140 170
145 a 190 ...


105
140


05
.84
40
66
24
c81
a
155
140
72
80
80?
44
c55
c42
60


c318
314 '
183


369
362



i33


301 G, X
390 D G, X
328 G, X
244 D. G, S, X
D, B


400
380
392



352
,o


465



.,


8
G, X
D, X
G;, x
D, S
S
S
D,


from driller's log or sam-
p1les.
0-45

Contaminated sam les.
Not characteristio--my be
absent.


3807 400? 50 Very large sample internal.
Each formation top may be
higher than shown. Tampa
not evident in samples or
driller's log.
e390 e440 D, G, 8, X Loss of circulation and eol-
lapse of hole prevented
sampling and electric log:
Lake City 1198 Oldsmar
1588.


... 81U 80 8
D,8


ii 6. 290? 380 398 470 8
12 I O ... ... D, 8


110
89
63
75
154
90
a
a?


120
76
82
68
a?


143
125
82
88
c185
102
a
160


130
98
110
106
107


2437
188

ei6i
240
200
230

2607
i66?

232
oo, *


4287
325

444i
310


563?



5i7


D, S

, X
X
XS

D, 8

D, 8
D, S




G

D, S


Tampa clay not evident in
samples or driller's log.
1st sample 290
Tampa clay not evident in
samples; shown on driller's
log.
Large sample interval.




Large sample intervals.
Tampa clay not evident in
samples-no driller's log.




Tampa not clearly evident
in samples, may be 10'.


Oy~- ~Wr___-l~y C1~ql~~______~ly_ I -I = -








TABLE 3 (Continued) a


APPROXIMATE DF.PTH TO TOP OF FORMATION.
Fo8 frwthom Oeala Group
U8Ga wet Altitude Formation Aron
well number o land (lir etone Tamps Suwnaee Crysta Park
number (W-) surface only) Formation Lmestone River Willton Inlle Limestone Datasouree Remarks


M3-153-28 3424 127

80-14-34 5444 136
803-154-85 524 el41
80-1B6-11 3773 147
804-138-1 1733 131
80 L138-2 5338 el33
g80-143-1 4412 e133
804-151-6 .... 129
804-I52-2 3707 118
804-153-4 3770 110
801-154-17 3764 148
" 80-2001 3838 157
806-152 3841 131
80-1548 t core el30
805-155-2 3765 135
S06-155-3 3765 135
805-156-2 3769 136
805-157-16 .... 165
805-159-1 2312 207
806-137-2 3207 178
806-137- 3799 145
806-188-2 8876 132
806-140-1 1753 133
806-142-1 1731 139
806-1496 3768 163
80-155- .3423 140
806-16-2 3771 136
80-158-7 53 e210
807-154-2 3763 136
807-154 3836 134
8W-154-4 3883 135
807-201-1 2774 142
808--151 3837 137
808-155-1 .... 138
808-201-1 4254 152
809-135-1 2869 125


48 86? 112


*82
115
&
a


-84


9-1


68


140
a
a

a
a
115
67?
a
a

a


c452




430
366
367


400


... ..,S


D, S

S

S
G, X
D. 8
D, 0, S
D, S
D, S. X
D, G, S, X
D G,. X
D. G. X
D: G, S
x
D, S
D. S
D,S
D
D, S
D, S
D, G, S
G, S
D, G, S
D, S
D, G, S
D, S


GX
D, S
S


Tampa not elearly evident
from samples-no driller'
lo0


Fiut same at
no driller log.


140'-


Top Lake City 1028' top



50 west of W-448







Questionable samples.

Top lake City 1110'.






809-136-2 4a63&
809-136-4 2013
809-147-1 4275
809-148-2 5045
809-153-3 3865
810-136-1 ....
810-144-1 4990
810-148-1
810-151-2
810-154-1 3867
810-155-1 3866
811-138-3 4919
812-135-1 46412
813-149-1 5046
813-201-1 5352
814-139-4 348
814-148-1
815-138-1 4964
815-142-1 2133
815-157-2 3839
816-148-1 4689
818-151-2 .
819-140-1 5016
819-147-1
Summer County:
821-2023 5054


Pasco County:
816-206-1 5350
Billaborough County:
742-216-1
744-226-10 ...
745-215-1 ...
751-203-1


i5
131
135
179
136
113
138
168
152
129
129
175
116
132
105
el50
136
173
143
109
128
124
213
128


a
a
a



el1
a



c55
a



a


17
a
a
a
I@5


a

a

e
a
a
a


24-
2.0
257
246
166
219
128
c236
260
247

125
220
160
154
90
125
145
126
235
c97


D. G. S, X
D, S
D. S
D. S
X, X
D, G, X
X
S

D, G, X
S
D, 8
D. G, X
8 ,

D, S,X

D. S. X
D. G, X
D. S
X


Irregular san.;We.-


-14
Wgi to 65
Bmied sinkhole

Tamp clay not indicated in
samples or driller's log.






Wgi 1077


96 a a0 72 101 136 D, G, S. X Avon Park top indicated also
by gamma-ray logp


21 40 8) 157 190 D, 8, X


eC
17
el55


. 147
302
274


e310

460


Intelpretation by H. 3.
Peek, (1959, fig. 15)


115 22S ... ... *. X






FLORIDA GEOLOGICAL SURVEY


the usage of the U.S. Geological Survey, with the exception of the
Ocala Group and its subdivisions, and the Tampa Formation of
Miocene age. The Florida Geological Survey had adopted the Ocala
Group as described by Puri (1957), but the U.S. Geological Survey
includes these strata in the Ocala Formation and the underlying
upper part (= Inglis Limestone of former usage) of the Avon Park
Limestone. The Tampa Limestone, as used by the U.S. Geological
Survey, is referred to as the Tampa Formation by the Florida
Geological Survey.

EOCENE SERIES
OLDSMAR LIMESTONE
Vernon (1951, p. 87, 92) and Cooke (1945, p. 40, 46) indicate
that the Oldsmar Limestone probably underlies all of peninsular
Florida, and that the thickness of the formation may range from
300 to 1,200 feet. They further indicate that the Oldsmar uncon-
formably underlies the Lake City Limestone.
Four test holes in Polk County penetrate the Oldsmar Lime-
stone. Applin and Applin (1944) examined the samples from well
750-148-1 and placed the 670-feet interval from 1,960 to 2,630 feet
in the Oldsmar. The cores and logs from two deep exploratory
holes drilled near Lakeland furnish much of the geologic informa-
tion used in this and the following sections on stratigraphy. One
core hole, about 3 miles southwest of Lakeland (well number 801-
200-3), was drilled to a depth of 1,842 feet. The other core hole,
about 5 miles northeast of Lakeland (805-154-8), was drilled to a
depth of 1,479 feet. Both of these holes terminated in the Oldsmar
Limestone. The abstracted logs of these two holes are given here
to aid in the discussion.

Core Hole 3 Miles SW of Lakeland (801-200-3)
Altitude of Land Surface is Approximately
135 feet above msl.
DEPTH IN FEET,
MATERIAL BELOW LAND SURFACE
Undifferentiated:
Sand and clay. 0-14
Hawthorn Formation:
Limestone. 14-93
Tampa Formation:
Clay, blue-green. 93-135







REPORT OF INVESTIGATION NO. 44


Core Hole 801-200-3-Continued
DEPTH IN FEET,
MATERIAL BELOW LAND SURFACE
Suwannee Limestone (start core at 139 ft.
3 in.): Chert, dark gray, very hard; re-
placed limestone, with pre-chert solutional
cavities up to 2% inches, filled with cream
limestone containing Sorites sp. Drilling
water circulation lost at 138 feet. 135-142%
Unidentified:
Not cored from 142% to 652%; all drilling
water circulation lost, no cuttings re-
turned.
Avon Park Limestone:
Open cavern. 440-445
Sand and mud (driller's interpretation),
probably cavern-fill, very soft. 445-455
Open cavern, casing slipped to bottom of
hole. 540 %-5471%
Casing set by water-jetting only; probably
sand and mud cavern-fill, very soft. 547%-576
Casing set by water-jetting and casing ro-
tation only; probably extensive honeycomb
and/or sand and mud cavern-fill, very soft. 576-653
In Avon Park Limestone (cored from 652 ft.
11 in. to total depth 1,842 ft.) :
Dolomite, replaced limestone, dark brown,
dense, broken and highly fractured (some
re-cemented). (See figure 4.) 653-665
Dolomite, as above, with solution cavities
up to 2% inches, and one open vug (after
gypsum) containing small amounts of
loose brown dolomite sand. Cavities are de-
veloped along fractures in cavern collapse
rubble. 665-670
Dolomite, as above, cavern-fill developed in
dolomitized collapse rubble (fill). 670-673
Dolomite, as above, badly broken to resem-
ble coarse gravel. May include a continua-
tion of pre-dolomite collapse zone above. 673-684
Dolomite, as above, a collapse rubble of
angular dis-oriented inclusions in finer
grained matrix. Cavities developed and
partly filled with brown dolomite sand (?). 684-685%
Dolomite, as above, badly broken in zones. 685%-703
Dip-slip faulting or slumping, and repeti-
tive thin beds due to overriding thrust. 703-






FLORIDA GEOLOGICAL SURVEY


Core Hole 801-200-3-Continued

DEPTH IN FEET,
MATERIAL BELOW LAND SURFACE
Thrust fault cutting a chert nodule. Slick-
lenslides on nearly horizontal bedding-
plane thrust. 703Y8-
Dolomite, as above, locally broken and
fractured. A few small solution cavities de-
veloped (vugs after gypsum?) 703-7221/
Dolomite, as above, a dolomitized rubble.
Angular inclusions up to 1% inches, in
finer grained matrix, have random orien-
tation. Believed of collapse origin, but pos-
sibly a pre-lithification sedimentary rubble. 7221/-725%
Dolomite, as above, badly broken and frac-
tured in some zones. 725%-742%
Dolomite, as above, collapse rubble, angu-
lar inclusions up to 2 inches in heteroge-
nous matrix, with random orientation of
inclusions. 742% -746
Dolomite, as above, massive and dense to
badly broken in zones, occasional solution
cavity up to % inch. 746%-778%
Clay. a sedimentary rubble. 778-780%
Limestone, soft, chalky; some fine to very
fine honeycomb development and occasional
cavities up to 1 inch. 780-875
Limestone, soft to hard in zones, solution tubes
up to '4 inch diameter and fine honeycomb
development. 875-951
Limestone, dolomitic?, hard with fine hon-
eycomb development. 951-1,068
Limestone, moderately soft, with tubes and
cavities up to % inch. 1,068-1,128
Lake City Limestone:
Limestone, soft to hard, chalky zones, low
permeability with occasional fine honey-
comb, abundant nodules and nests of nod-
ules of gypsum altered from anhydrite.
Abundant and general impregnation by
selenite. Some open pore-space and molds,
but not common. 1,128-1,451
Dolomite, replaced limestone, very hard,
general selenite impregnation, but some
open pore spaces, small tubes and cavities,
gypsum nodules altered from anhydrite.
Fractures, vertical to high-angle, in lower
part are re-cemented by selenite. 1,451-1,588






REPORT OF INVESTIGATION NO. 44


Core Hole 801-200-3-Continued
DEPTH IN FEET,
MATERIAL (Con't) BELOW LAND SURFACE
Oldsmar Limestone:
Dolomite, hard, pore space as molds and
fine honeycomb, generally selenite impreg-
nated; gypsum nodules altered from anhy-
drite, some selenite cemented fractures.
Some thin zones of dolomite sand (?). 1,588-1,688
Dolomite, as above, dolomite sand (?)
zones more numerous and thicker with
very high porosity; a few scattered open
vugs after gypsum (?) excavation. Gyp-
sum nodules altered from anhydrite. Sele-
nite impregnation of dense dolomite zones. 1,688-1,746
Dolomite, as above, abundant nests and
scattered gypsum nodules altered from an-
hydrite; selenite as impregnation and frac-
ture cement. 1,746-1,812
Anhydrite, white, massive, single bed. 1,812-1,816
Dolomite, as above, scattered anhydrite and
gypsum nodules, scattered occurrences of
dolomite sand (?), extensive selenite im-
pregnation of massive dolomite, and post-
dolomite fractures. 1,816-1,842

Core Hole 5 Miles NE of Lakeland (805-154-8)
Altitude of land surface is approximately
130 feet above msl.
Undifferentiated:
Sand and clay. 0-50
Hawthorn Formation:
Limestone. 50-58
Tampa Formation:
Clay, blue-green. 58-60
Suwannee Limestone:
Limestone, detrital, very soft, chalky, little
evidence of solutional activity. 60-151
Ocala Group
Crystal River Formation:
Limestone, soft, granular to very chalky,
little evidence of solutional activity. 151-276
V illiston Formation:
Limestone, soft to moderately hard, granu-
lar, local dolomitized zones, some solutional
removal of calcite matrix. 276-286





FLORIDA GEOLOGICAL SURVEY


Core Hole 805-154-8-Continued
DEPTH IN FEET,
BELOW LAND SURFACE
Inglis Formation:
Limestone, granular, soft to hard, locally
dolomitized, note solutional removal of ce-
ment and fossil molds, fine solutional tubes,
and local honeycomb. 286-345%
Avon Park Limestone:
Limestone, hard to soft, granular to
chalky, visible porosity moderate to very
high in granular zones. 346-4441%
Dolomite, replacement of limestone, very
hard and dense; solution tubes 1 inch x 14
inch diameter. (First such features noted.) 444%-449%
Lost drilling water circulation. 512-
Dolomite, replacement of limestone, very
hard; dense to granular, low to very high
visible porosity. 521-615
Lost drilling water circulation. 529-
Fine honeycomb. 534-536
Dense, badly broken, as dolomite
"gravel." 538-542
Dense, thin bedded, with zones of fine
honeycomb. 542-552
Badly broken, as gravel, some solution
along fractures. 552-553
Badly broken, as gravel, in zones. 556-564
Collapse rubble zone; angular inclu-
sions up to 4 in. Random orientation,
one 3 in. piece is thin-bedded with bed-
ing-tipped vertical, matrix fine-grained
and thin bedded. 566-567
Collapse rubble, angular, badly broken. 574%-575
Dense, badly broken. 575-578%
Collapse rubble, very angular inclu-
sions up to 2 in. Random orientation,
yellow thin-bedded inclusion tilted with
bedding at high angle to core. Some sol-
ution along fractures through interval.
This interval may be essentially con-
tinuous from 574%. 578%-588
Dense, badly broken. 597-610%
Limestone, moderately soft, very fine hon-
eycomb developed. 621 -623%
Limestone, soft to moderately hard, some
small tubes and fine honeycomb. At 685
feet first open vug from removal of gyp-
sum alteration of anhydrite nodules. 623%-685






REPORT OF INVESTIGATION NO. 44

Core Hole 805-154-8-Continued


Limestone, collapse rubble, middle 1% foot
dolomitized. Post dolomite fractures.
Collapse rubble continues from 695; core
shows old cavern wall and fine-grained fill
with larger inclusions. Badly broken in
lower part; fine second-stage solution hon-
eycomb developing in dolomite.
Dolomitized collapse rubble with post-
dolomite fractures.
Limestone, generally chalky and soft to
moderately hard in thin local partially dol-
omitized zones. Visible porosity low to
moderate due to fossil molds and fine hon-
eycomb development. Numerous large (to
2%-in.) irregular vugs resulting from so-
lutional excavation of gypsum altered from
rubble of anhydrite nodules. Abundant cal-
cite crystals in vugs below 879 feet, and a
few quartz crystal growths noted. Oc-
casional silicified clay beds a few inches
thick.
Lost drilling water circulation; regained
and partial loss of circulation again at 796
feet.
Limestone, chalky, very soft to moderately
soft, heavy selenite impregnation of pores
and molds. Nodules of gypsum (after an-
hydrite) up to 1% in.
Lake City Limestone (1,028-1,445%):
Limestone, chalky, soft; contains irregular,
rounded, nodules of gypsum altered from
anhydrite rubble. Profuse selenite impreg-
nation of pore space, but some small open
solutional cavities and fossil molds noted.
Visible porosity generally low.
Limestone, dolomitic, with gypsum as above.
Dolomite, replaced limestone, hard, crystal-
line. Gypsum nodules as above, selenite im-
pregnation, and some small open pore
space.
Dolomite, as above, with small cavities con-
taining dolomite-sand fill. Gypsum as
above.
Limestone, dolomitic, moderately soft to
moderately hard, low porosity. Selenite im-
pregnation and gypsum as above. Occa-
sional open vug after gypsum.


DEPTH IN FEET,
BELOW LAND SURFACE

695-698




698-704

716-717











717-1,015%


785-



1,015%-1,028






1,028-1,295%
1,295%-1,374%



1,374%-1,386


1,386-1,392%


1,392%-1,445%


25





FLORIDA GEOLOGICAL SURVEY


Core Hole 805-154-8-Continued
DEPTH IN FEET,
BELOW LAND SURFACE
Oldsmar Limestone (1,445%-1,479):
Limestone, dolomitic, moderately hard.
Small gypsum nodules as above, a few
small vugs after gypsum. Some selenite
impregnation and fine honeycomb. 1,445 -1,459
Dolomite, replaced limestone, dense, hard;
scattered gypsum as above, and some sele-
nite impregnation; fine honeycomb zones
and rare small open vugs after gypsum. 1,459-1,479
On the basis of the major change in character of the electric
and gamma-ray logs, and lithology, the lower 331/L feet (1,4451,X-
1,479 feet) of well 805-154-8 and the lower 258 feet (1,588-1,846
feet) of well 801-200-3 are tentatively designated as Oldsmar
Limestone.
In wells 801-200-3 and 805-154-8, the Oldsmar is a grayish-tan
to brown, very hard, finely crystalline, highly dolomitized, gypsi-
ferous limestone. Generally, dolomitization appears to follow
bedding planes and is inter-bedded with a few soft, calcareous
zones. Color of the formation becomes more grayish downward
with increasing amounts of disseminated peat.
The formation contains rubble-beds which are generally less
than a foot thick, which were formed before the sediments were
firmly cemented and lithified. These are interpreted as bottom
sediments which have been broken up by wave action while in a
semi-plastic state, then re-deposited and cemented. Such changes
may reflect storm waves of greater than normal proportions. The
formation also contains sequences of thin, individual graded-beds,
each bed being only 1 or 2 inches thick. These graded-beds, and the
rubble-beds, indicate rapidly changing sedimentary conditions in
a relatively shallow sea or embayment. Such changes may have
been short-lived and of generally small magnitude. Thick peat a:-
cumulations at the top of the formation were interbedded with
rubble-beds. Other rubble-beds were found throughout the forma-
tion. Further study of such features in these two wells will pro-
vide more information about the environment of deposition of tle
formation.
In wells 801-200-3 and 805-154-8 in the Lakeland area, the con-
tinuous cores from the Oldsmar Limestone contain considerable
amounts of anhydrite, gypsum, and selenite, a clear crystalline
variety of gypsum. A solid bed of anhydrite was encountered from






REPORT OF INVESTIGATION NO. 44


1,( 12 to 1,816 feet in well 801-200-3. With this exception, the
an iydrite and gypsum in the Oldsmar occurred as rounded irreg-
ul;tr nodules that are several inches long in the greatest dimension.
The nodules were not apparently oriented and were scattered as
individual nodules or deposited in clusters that seldom exceeded a
foot in thickness. The nodules were originally anhydrite and all
but a few in the lower part of the formation have been partly or
completely altered to gypsum by varying degrees of hydration.
Most of the gypsum nodules contain a large core of unaltered an-
hydrite. This alteration is accompanied by a 30-50 percent in-
crease in volume (Pettijohn, 1949, p. 356), and the increase was
evidenced by the fracturing and filling of adjacent limestone
stringers and walls. The evaporites usually originate as bedded
deposits in closed shallow basins. The occurrence here as separate
nodules is interpreted as being the rubble of originally bedded de-
posits which have been destroyed by wave action. The size and
shape of the nodules suggest that the rubble was transported a
relatively short distance before re-deposition. Such an interpreta-
tion is consistent with that of the pre-lithification sedimentary
rubble beds mentioned previously. Selenite occurred in much of the
formation as an impregnation of pore spaces and as fracture filling
or cement. The selenite probably represents a further alteration,
or solution and precipitation, of gypsum. Several small nodules of
gypsum have been completely dissolved leaving open vugs in the
rock. These vugs have intricate irregular walls like those enclosing
the nodules cut by the drill, and there can be no doubt as to the
origin of the vugs.
In the core samples from wells 801-200-3 and 805-154-8 the
contact of the Oldsmar with the overlying Lake City Limestone is
indefinite and appears to be a disconformable zone, rather than
an erosional unconformity. The disconformable zone appears to
be about 30 feet thick and contains large quantities of peat or
low-grade lignite. The peat is thought to be of marine origin and
to represent a long period of very shallow water conditions and
li tle deposition. The presence of gypsum and anhydrite nodules in
th;e disconformable zone and subjacent beds of the Oldsmar indi-
c te the absence of fresh water erosion or circulation of fresh
r 'ound water after deposition.
Excellent correlation of the disconformable interval was made
b gamma-ray logs of the two wells, which showed marked in-
c eases in radioactivity in the thick peat zone at the top of the
f rmation. The disconformable zone appears to be unfossiliferous,





FLORIDA GEOLOGICAL SURVEY


but this may be partly due to intense dolomitization and resultant
destruction of fossils. The peat occurs as beds from 6 to 14 inches
thick, as thin seams and bedding-plane films, and as disseminated
flakes. Only a slight change in color and lithology may be noted in
passing downward from the Lake City Limestone into the Oldsmar
Limestone.
In wells 801-200-1 and 805-154-8 the formation has very low
visible porosity and permeability. Both porosity and permeability,
seem to increase in fractured dolomitized zones, but some of these
zones have been partially re-cemented or filled with selenite. The
presence of selenite, gypsum, and anhydrite throughout the for.
mation clearly shows that there has never been a significant
amount of fresh ground water in it, because these minerals are
soluble and would have been removed.

LAKE CITY LIMESTONE
The Lake City Limestone is penetrated by relatively few wells
in this county, and only four wells are known to pass entirely
through the formation.
According to Cooke (1945, p. 46), the formation underlies all
but the northwestern part of the state. Samples were not collected
from this formation in well 811-149-1. According to Cooke (1945,
p. 48), the Lake City was encountered in well 750-148-1 at a depth
of 1,540 feet, and it extends to a depth of 1,960 feet.
In well 805-154-8 a selenite and peat (?) replacement of
Dictyoconus americanus, the index fossil of the Lake City, was
recovered from the core at a depth of 1,0281/ feet. Identification
was based on the internal cell structure as illustrated by Applin
and Jordan (1945, p. 136, fig; 2). Other specimens were observed
in the core at this depth.
The electric log of this well shows a decrease in both resistivity
and self-potential at a depth of 1,028 feet in a moderately soft,
clayey, chalky zone of low visible porosity. The top of the forr;i-
tion is therefore placed at 1,028 feet in this well, and the forria-
tion continues to a depth of 1,4451/2 feet. The formation top on
this electric log correlates very closely with the electric log of
nearby well 807-154-4 at a depth of 1,110 feet. This depth (1,.10
feet) also coincides with the first occurrence of chert and gyps m
in the well according to a log prepared by E. W. Bishop of he
Florida Geological Survey (FGS W-3883, July 17, 1956). BisI op
(op. cit.) designates the interval 1,110-1,198 feet as Avon P'rk






REPORT OF INVESTIGATION NO. 44


Linestone. In well 801-200-3 the Lake City Limestone is identified
in the interval from 1,198 to 1,588 feet by correlation of electric
and gamma-ray logs with those of well 805-154-8. On the basis of
these three wells, the thickness of the Lake City Limestone ranges
from 4171/ to 420 feet in Polk County.
In wells 801-200-3 and 805-154-8 the Lake City Limestone is a
white to cream, moderately soft to hard, chalky limestone. The
lower 75 to 130 feet of the formation contains finely crystalline,
highly dolomitized zones which appear to follow bedding planes.
'The formation contains abundant peat films on bedding planes.
Scattered chert nodules occur in the upper part of the formation
and few thin apparent chert "beds" in the lower part of the for-
mation may actually be small nodules or lenses. All of the chert
appears to be of secondary origin as a replacement of limey sedi-
ments. Pre-lithification sedimentary rubble-beds, generally a few
inches thick, are abundant throughout the formation in both wells
801-200-3 and 805-154-8.
In wells 801-200-3 and 805-154-8 the Lake City Limestone con-
tains abundant anhydrite, gypsum, and selenite. The nodular
mode of occurrence of these minerals in the Lake City is the same
as that previously described in the Oldsmar Limestone. The same
interpretation of origin and alteration, from original bedded an-
hydrite to nodular gypsum and selenite, also applies to the Lake
City. However, the Lake City in these two wells does not contain
bedded, or unaltered nodules of anhydrite. In general, the anhy-
drite cores of the nodules decrease in size upward and completely
altered nodules of gypsum are common. Individual nodules reach
as much as 12 inches in their greatest dimension. Selenite im-
pregnation of pore spaces, small solutional tubes and cavities,
small vugs, and fractures occur throughout much of the forma-
tion. Open vugs, generally less than 1 inch in diameter, resulting
from solutional removal of anhydrite-gypsum nodules occur
throughout the formation. These are relatively few in number, but
are more numerous than in the Oldsmar.
Cooke (1945, p. 46) and Vernon (1951, p. 92, 99) indicate that
f'e contact of the Lake City and the overlying Avon Park Lime-
s'one may be unconformable. In the cores from wells 801-200-3
I d 805-154-8 the contact zone is not obvious. In well 805-154-8
r. psum nodules occur at 1,038 feet, 10 feet below the contact. In
v ell 801-200-3 gypsum nodules occur throughout the contact zone
; id adjacent beds. The occurrence of gypsum nodules and the con-
t nuity of lithology strongly suggest that the contact is transi-






FLORIDA GEOLOGICAL SURVEY


and their significance will be discussed in more detail in the sec
tion on solutional features.
The Avon Park contains anhydrite-gypsum nodules in the same
mode of occurrence as has been previously described in the Olds-
mar and Lake City Limestones. The same interpretations of origin
and alteration, from original-bedded anhydrite to nodular gypsum
and selenite, stated for these earlier formations is also applied to
the Avon Park. However, in wells 801-200-3 and 805-154-8 the
Avon Park does not contain unaltered anhydrite, and it now con-
tains considerably less total anhydrite, gypsum, and selenite than
the two underlying formations. In well 801-200-3, the cored well
southwest of Lakeland, the Avon Park contained scattered gyp-
sum nodules and clusters and selenite impregnations only in the
lower 70 feet (1,128-1,198). In well 805-154-8, northeast of Lake-
land, the Avon Park contained such deposits only in the lower 13
feet (1.015-1,028). In both wells the gypsum nodules contained
cores of anhydrite.
There is no doubt that the Avon Park once contained a much
greater amount of the evaporate nodules. In well 805-154-8 many
open vugs with irregular, concavely rounded walls, occurred at
depths of 685 to 885 feet. It seems clear that these vugs result
from the complete solutional removal of evaporite nodules. The
open vugs were scattered and sparse in number from 885 to 1,015
feet. Only a few vugs were found in the cores from well 801-200-3
and these occurred from 829 to 1,128 feet.
The Avon Park Limestone contains numerous thin, porous,
granular, sand-like zones of dolomite, the origin of which is un-
known. There are several suggested origins that may be possible:
(1) Some zones may be a depositional dolomite-sand in solutional
cavities; (2) some zones may be an ultra-fine honeycomb de-
veloped along fractures and other openings by solution; and (3)
some of the zones may be the result of precipitation of ultra-fine
dolomite crystals. Such zones are also found in the dolomitized
zones of the underlying Lake City and Oldsmar Limestones.
The formation also contains, particularly in the lower part,
numerous chalky or clayey zones; some thin, well-defined calcare-
ous clay beds; and abundant peat as thin films on bedding planes.
There are also chert nodules, apparent chert beds, and diffused
silicified zones.
Vernon (1951, p. 99) states that both of the formational con-
tacts are erosional unconformities. The present studies of cores
from wells 801-200-3 and 805-154-8 in the Lakeland area, and






REPORT OF INVESTIGATION NO. 44


iany sets of cuttings indicate that the contact in Polk County is
.:nconformable. The lower few feet of the overlying Inglis For-
.ation generally contain pieces of dark, granular rubble up to
1-inch diameter and abundant eroded Dictyoconus sp. and
S'oskinolina sp. from the Avon Park. This is interpreted as
weathered Avon Park Limestone, eroded and re-deposited in the
early stages of Inglis deposition and hence an unconformable con-
tact.
Permeability of the formation ranges from very low in some
of the clayey or chalky zones to extremely high in cavernous
zones. The visible porsity and permeability of the formation, as a
unit, is high and it is the greatest water-producing unit in the
Floridan aquifer in Polk County. Local areas in which the for-
mation as a whole is of low permeability have been encountered,
but these are relatively few in number.
OCALA GROUP
In recent years the Florida Geological Survey has subdivided
the rocks formerly grouped within the Ocala Limestone. Vernon
(1951, p. 113-171) divided this sequence of rocks into the Ocala
Limestone (restricted) and the Moodys Branch Formation. He
divided the Moodys Branch Formation of his usage into two parts.
The lower unit was named the Inglis Member, and the upper unit
was named the Williston Member.
Puri (1953a, 1957) gave the name Crystal River Formation to
Vernon's restricted Ocala Limestone and gave formation rank to
Vernon's Inglis and Williston Members of the Moodys Branch
Formation. The Crystal River, Williston, and Inglis Formations
are now referred to as the Ocala Group by the Florida Geological
Survey and the name Moodys Branch Formation is no longer used
in Florida. The northeastern half of Polk County is underlain by
the Ocala Group as shown in figure 5.

Inglis Formation
The Inglis Formation underlies almost the entire county except
in local areas in northeastern part and is a white to cream to dark
brown, generally hard to very hard, granular, partially to highly
dolomitized, highly fossiliferous limestone with some local soft
chalky zones. In the area lying generally north and west of Polk
City, the formation is highly dolomitized, very hard and contains
many sand-filled solutional cavities.
In the central part of the county the formation has a relatively






FLORIDA GEOLOGICAL SURVEY


uniform thickness of 35-45 feet. In well 821-202-3 in Sumter
County, northwest of Rock Ridge (fig. 4), the Inglis is 29 feet
thick. This well is located along the crest of the major structural
feature in the area. In well 805-154-8, northeast of Lakeland, the
Inglis is approximately 50 feet thick. It thickens slightly along the
extreme western part of the county to about 45-50 feet. In the
southeastern part of the county the Inglis is as much as 95 feet
thick.


Figure 5. Geologic map of the pre-Miocene formations.


The Inglis is the uppermost limestone in extreme north-
eastern Polk County due to erosion of the overlying beds along
the crest of a structural high. The Inglis conformably underlies
the Williston Formation, and unconformably overlies the Avon
Park Limestone. (Vernon, 1951, p. 212).
In well 805-154-8 the Inglis appears to have low to moderate
porosity in the upper part of the formation. Moderate to high
visible porosity in the lower part of the formation is due to the






REPORT OF INVESTIGATION NO. 44


.emoval of the calcite cement and matrix in the granular and
'ossiliferous zones. The Inglis is one of several formations usually
)enetrated by water wells in this area. Locally it may be a good
producer due to cavernous conditions and/or its generally granu-
lar texture. However, wells are not usually drilled for the purpose
of obtaining water from this formation.
Williston Formation
The Williston Formation is a white to cream to brown lime-
stone, and is a generally soft, coarse, coquina of foraminifera,
set in a chalky calcite matrix. The lower 5-15 feet are usually
harder than the rest of the formation due to dolomitization. The
formation has moderate visible porosity. The Williston is gener-
ally less highly dolomitized than the underlying Inglis Formation.
The formation underlies most of the county with a thickness
which ranges from 10 to 100 feet, and averages about 30 feet.
These thicknesses are based principally upon electric-log determi-
nations. In extreme northeastern Polk County the formation is
missing, having been removed by erosion, and may be missing
from other local areas near the crest of the structural high.
Vernon (1951, p. 143) states that the formation lies con-
formably between the Inglis and the overlying Crystal River
Formation. The lower contact is marked by a distinct lithologic
change, but the upper contact is transitional and very difficult to
define.
The Williston is one of several formations usually penetrated
by water wells in this county, and it is believed to contribute some
water to wells. The general character of the formation (soft,
coquinoid, and chalky matrix) results in a lower porosity and
permeability, as compared to the more productive underlying
formations.

Crystal River Formation
In the subsurface the Crystal River Formation is a white,
gray, cream, or tan, generally very soft, coarse, granular, lime-
stone of very high purity which contains great numbers of large
foraminifera in a chalky carbonate matrix. Locally it may contain
thin hard dolomitized beds or zones which are controlled by
bedding.
The Crystal River is easily recognized from the abundance of
disc-shaped foraminifers of the genus Lepidocyclina. In some of
the species the disc has a saddlelike shape. The formation com-





FLORIDA GEOLOGICAL SURVEY


only is referred to as "Ocala," "shell," or "limeshell" by local
drillers.
The formation ranges in thickness from 80 to 125 feet in an
east-west belt across the county between Lakeland and Ft. Meade.
South of this belt it thickens gradually southward to 150 feet,
possibly even thicker locally. North of the belt, it ranges from
30 to 60 feet in thickness due to erosion and has been entirely
removed from broad areas lying northeast of Polk City. The for-
mation has been removed by erosion in the vicinity of eastern
Winter Haven, where the Williston Formation appears to be di-
rectly overlain by the Suwannee Limestone. Both the Crystal
River and Williston have been removed by erosion from the
vicinity of Haines City and the Inglis is directly overlain by the
Suwannee Limestone.
The Crystal River is the uppermost Limestone in the northern
part of the county due to erosion of the overlying Suwannee and
younger formations. Along the crest of the structural high area
in northwestern Polk and adjacent parts of Lake and Sumter
counties, the Crystal River Formation is at, or within a few feet
of the surface over an area of approximately 100 square miles.
This outcrop area has not been previously mapped or described
in any literature. The outcrop area was mapped and studies in a
reconnaissance by E. W. Bishop, geologist, Florida Geological
Survey, and the author in April 1957. The results are discussed
here with the permission of Mr. Bishop."
Throughout the area of surface exposure the limestone is silici-
tied by replacement with hard, dark gray to white chert. In these
exposures the fossil content has been generally destroyed by the
replacement, but locally small concentrations of Lepidocyclina
ocalana were found. Lepidocyclina ocalana is a diagnostic fossil
of the Crystal River and is usually abundant in the formations.
Numerous echinoids were observed in many parts of the out-
crop area. In some locations the echinoids were found adjacent
to occurrences of Lepidocyclina ocalan. More than 40 specimens
of echinoids were collected, and they appear to represent a single
species. Nine of the best specimens from the area of outcrop, and
one from a limestone pit at Lacoochee, Pasco County, were
identified as Rhyncholampas (Cassidulus) gouldii (Bouve) by
Mr. Porter Kier, Associate Curator, Division of Invertebrate
Paleontology and Paleobotany, U.S. National Museum.4 Cassidu-
Personal communication, E. W. Bishop, December 12, 1960.
SPersonal communication, Porter M. Kier, April 10, 1961.






REPORT OF INVESTIGATION NO. 44


?us gouldii (Bouve) is a diagnostic fossil of the Suwannee Lime-
stone of Oligocene age, which normally overlies the Crystal River.
The echinoids are preserved as filled molds, the filling being
.1 miliolid-rich granular limestone. In one such echinoid, a speci-
men of Dictyoconus cookei was found and, although this fora-
minifer is diagnostic of the Avon Park Limestone, it is also fre-
quently found in the Suwannee Limestone.
Because of the observed association of Suwannee and Crystal
River fauna the outcrop area is interpreted as being the eroded
remnant of the original contact zone of the two formations. Such
interpretation thus places the thickness of the Crystal River on
the crest of the Ocala uplift at 60 feet or less. Only one outcrop
of slightly calcareous limestone was observed.
A well in the outcrop area in southern Sumter County, 821-
202-3, penetrated 72 feet of the Crystal River Formation.
Surrounding the area of outcrop is a broad belt of boulders
and isolated boulders and cobbles. The closeness of the formation
to the surface is inferred by the presence of many silicified and
sparsely fossiliferous boulders and cobbles in the spoil piles or
in the bottoms of the extensive shallow drainage canals in the
area. Many of the boulders and some of the outcrops showed
extensive solutional erosion prior to silification. It is evident that
some of the boulders were originally geodes or parts of small
caverns that were armored through replacement by, or deposi-
tion of, gray to white chert, while the main body of limestone
remained unaltered and soluble. Subsequently the soluble lime-
stone portions of the formation were removed by chemical and/
or mechanical erosion, during exposure at land surface, leaving
the resistant silicified solutional features. Several boulders con-
tained solutional cavities lined with banded, botryoidal, amor-
phous chalcedony, and geode-like, clear, quartz-crystal growths.
The Crystal River, according to Vernon (1951, p. 160) lies
conformably upon the Williston Formation and is unconformably
overlain by the Suwannee Limestone of Oligocene age, or by
younger unconsolidated clays and sands.
In well 805-154-8 the Crystal River is 124 feet thick and
has low to moderate visible porosity and permeability. Small
incipient solutional tubes and cavities were observed in the in-
terval from 182 to 224 feet. Cores were not taken from this forma-
tion in well 801-200-3.
The yield of wells terminating in the Crystal River Formation
is considerably less than those drilled into the Avon Park Lime-






FLORIDA GEOLOGICAL SURVEY


stone, due to the very soft, chalky matrix. The yield of such a
well can usually be increased by deepening the well into one or
more of the underlying formations. The formation will generally
produce a sufficient quantity for domestic supplies.

OLIGOCENE SERIES

SUWANNEE LIMESTONE

The Suwannee Limestone is white, cream, or tan, generally
very soft, granular, detrital limestone which is generally- very
pure. Locally, however, it contains a small amount of fine quartz
sand as disseminated grains. It contains abundant bryozoa, small
mollusca, and large echinoids. Local drillers refer to it as the
"coquina." In some places the upper surface, and/or a zone near
the middle of the formation, is replaced by dark-brown or gray
chert which commonly ranges from a few inches to a few feet
thick. The greatest thickness of chert encountered, or reported,
in the county was 10 feet in well 803-156-11 in Lakeland. The chert
zone occurred from 2081 to 2181 feet, near the middle of the for-
mation. The area of Polk County underlain by the Suwannee Lime-
stone is shown in Figure 5.
In well 805-154-8 the formation is 91 feet thick and contains
thin hard dolomitic zones from 73 to 75 feet. The formation con-
tains some small solutional tubes and cavities which are lined with
small calcite crystals. The lower portion of the formation is
chalky and less granular than the upper part. The Suwannee in
this well has a moderate to low visible porosity and permeability.
The lower few feet appear to be an indistinct pre-lithification
rubble zone, and contain films of black peat along bedding planes.
The thickness of the Suwannee in well 801-200-3 is unknown
due to loss of cuttings and circulation at 136 feet. In this well,
however, the upper 3 feet of the formation was cored, and is a
complete replacement by gray chert. The silicification preserved in
detail many solutional cavities in the limestone. Some of these
cavities contained a filling of cream colored sandy limestone,
which contained a number of Sorites sp., and which is tentatively
identified as limestone of the Hawthorn Formation of Miocene
age. This clearly establishes one reason for the finding of this
particular fossil, as reported by Stewart (1959, p. 22), in what
might otherwise be considered as slightly sandy Suwannee Lime-
stone.






REPORT OF INVESTIGATION No. 44


Thickness of the Suwannee generally ranges from 80 to 120
feet in the central and southern parts of the county. It thickens
rather abruptly from 70 feet in a well southwest of Lakeland
(759-201-1), to 195 feet in a well in south-central Hillsborough
County (746-209-1). In the northern part of Polk County the
formation thins considerably due to both depositional and erosional
thinning, and is absent in much of the northern and eastern
parts of the county (fig. 5).
In several sets of well cuttings the Suwannee Limestone con-
tained some fossils that are diagnostic of the Crystal River For-
mation. Some of these samples also contained a few specimens
of the Suwannee foramanifer Rotalia mexicana, which is not a
durable fossil. Such rocks, though containing predominantly
Crystal River fossils, are interpreted as Suwannee Limestone.
They indicate local erosion and re-deposition of Ocala rocks during
deposition of the Suwannee. An example of such deposits was
found in the upper 36 feet of limestone in well 800-142-1.
The yield of wells terminating in the Suwannee Limestone
is considerably less than those in the Avon Park Limestone, but
is generally greater than the yield of wells in the Crystal River
Formation. The Suwannee furnishes adequate supplies for domes-
tic and small irrigation wells, and it is widely used for these
purposes.

MIOCENE SERIES
The correlation of the formations of Miocene age in Florida
and adjacent states has long been a major geologic problem. Re-
cently great strides have been made with this problem in the
Florida panhandle by Puri (1953b). Major problems still exist,
however, in the peninsular part of the state. Reports by Bergen-
dahl (1956, p. 69-84), Cooke (1945, p. 109ff), Vernon (1951,
p. 178-186), Puri (1953b, p. 15 ff), and others contain summar-
ies of the problem.
In recent years the Miocene and younger deposits in the cen-
tral part of the peninsula have been studied by many geologists
of the U.S. Geological Survey. Some of the findings are reported
by Cathcart and McGreevy (1959), Ketner and McGreevy (1959),
Carr and Alverson (1959), Altschuler, Jaffee, and Cuttitta
(1956), Altschuler, Clarke, and Young (1958), Altschuler and
Young (1960), and others. With these recent contributions some
of the questions regarding the Hawthorn and Tampa Formations
may have been resolved, but in the case of the limestone units






FLORIDA GEOLOGICAL SURVEY


of these formations, which are widely used ground-water aquifers,
a basic practical problem of identification and delineation still
exists.
The chemical and lithologic constitution (Carr and Alverson,
1953, p. 175 ff) of the limestone units of the two formations is
identical for field mapping purposes. The fossil fauna is largely
mollusca which are not individually diagnostic of either forma-
tion, and faunal assemblages are only generally diagnostic of the
early and middle Miocene ages presently assigned to the Tampa
and Hawthorn Formation respectively (Vernon, 1951; Puri,
1953b; Espenshade and Spencer, 1963). Identification of these
formations is made even more unlikely in Polk County because
of dolomitization and because most of the geologic work must be
done from well cuttings, in which large mollusca molds are rarely
recovered intact. Sorites sp., common to the Tampa but not diag-
nostic of it, has not been found in known exposures of the Haw-
thorn, but has been found in well cuttings in both typical
Suwannee and Hawthorn lithology, thus complicating the prob-
lem further. Archaias floridanus, a foraminifer commonly ac-
cepted as diagnostic of the Tampa, has not been found in well
cuttings in this area.
TAMPA FORMATION
Cole (1941, p. 6) identified the Tampa between the depths of
117 and 180 feet in a well 4 miles north of Lakeland (805-157-15)
at the Carpenter's Home, on the assumption that the Tampa
Formation underlies all of Polk County, and on the basis of
general lithology, and an interpretation of fossil evidence. In
his diagrammatic illustration of the well (op. cit., p. 5, fig. 2)
he also includes the interval of 180 to 250 feet in the Tampa.
This well was in use during the entire course of the present in-
vestigation, and exploration of the well was not possible. How-
ever, on the basis of an electric log obtained in well 805-157-16,
approximately 50 feet west of the well described by Cole, the in-
terval 117-250 feet was determined to be the Suwannee Limestone.
Cooke (1945, p. 132) states that the Tampa probably under-
lies all of Polk County south of Lakeland. Vernon (1951) does
not discuss the Tampa Formation in his description of strati-
graphic units. Cathcart and McGreevy (1959, p. 228) found the
Tampa Limestone in western Polk and adjacent parts of other
counties, and report it to be a sandy, clayey, limestone containing
abundant chert fragments and very few phosphate nodules. They






REPORT OF INVESTIGATION No. 44


tate that the limestone is interbedded with clay and sandy clay,
: nd describe a locally developed residual mantle of green calcare-
Sus clay which contains chert and limestone fragments and a
ew phosphate nodules.
Ketner and McGreevy (1959, p. 59-65) consider the Tampa
Limestone to consist of three units, only two of which are present
in Polk County. Their upper, so-called "phosphorite unit" lies
north of this county and does not occur in the area of this investi-
gation. In northern Polk, according to Ketner and McGreevy, the
Tampa is represented by a limestone unit and a clay unit. The
clay unit consists of "greenish-gray to brown clay containing
well-sorted, very fine- to fine-grained quartz sand. Sand ranges
from 5 to 80 percent, averaging about 35 percent." They further
state that the clay unit "apparently grades into the limestone
unit of the Tampa about where the limestone unit of the Haw-
thorn Formation appears." Their limestone unit of the Tampa
is described from an exposure in the Tenoroc Mine of the Coronet
Phosphate Co., northeast of Lakeland, as being fossiliferouss,
yellow, somewhat soft, clayey, and sandy. The sand consists of
very fine- to fine-grained quartz and sand- to pebble-sized, rounded,
polished phosphorite nodules." They do not describe the areal
extent of the limestone unit, but identify it in two drill holes.
Carr and Alverson (1959, p. 14-33) present the most complete
studies and discussions of the Tampa in recent years and extend
the formation eastward from Tampa Bay as far as central Polk
County. According to these authors, the Tampa is a white to
light yellow, soft, moderately sandy and clayey, locally phosphatic,
finely granular, and locally highly fossiliferous limestone. They
state that both marine and fresh water limestones are present,
and that both upper and lower contacts of the formation are
erosional unconformities. Further, they state that limestone com-
monly interfingers with calcareous sandy clay which may be
equivalent to, or be, the Chattahoochee facies of Puri (1953b,
p. 20). If so, this is the first such recognition in this area.
They describe a section of the formation near the Hillsborough
River Dam as illustrating the interfingering of the clay and
limestone beds. They state-"Most clayey beds in the Tampa
limestone are small lenses, but several wells in Polk County, in-
cluding two drilled in 1952 at the Davison Chemical Corp. in
western Polk County, were drilled through about 50 feet of rather
uniform greenish-gray dolomitic sandy clay. This unit is tenta-
tively placed at the base of the Tampa; in the Davison wells it






FLORIDA GEOLOGICAL SURVEY


rests in sharp contact upon pure, white limestone containing
Cassidulus gouldii (Bouve). The wells in which the unit was noted
roughly delimit an area with corners near Mulberry, Lakeland,
Winter Haven, and Fort Meade." The Davison wells referred to
here are wells 754-155-1 and -3 of this report.
The Tampa Formation has been identified in relatively few
wells in this county. Open-file logs of the Florida Geological
Survey by E. W. Bishop and R. O. Vernon identify the Tampa
Formation from faunal evidence in a well south of Frostproof
(742-131-2), and a well at Lake Wales (753-134-4). Examination
of cuttings of the thick Miocene section in a well southwest of
Lakeland (801-200-3), revealed no limestone in the Tampa For-
mation. Cuttings from wells 754-155-1 and -3 were studied and
no evidence was found on which to base identification of Tampa
limestone units in these wells as identified by Carr and Alverson
(1959, p. 25, and fig. 7).
Field evidence obtained during the. earlier phases of this in-
vestigation (Stewart, 1959, p. 22) did not justify an identifica-
tion of limestone in the Tampa in northwestern Polk County. A
slightly sandy limestone, similar in lithology to early descrip-
tions of the Tampa was noted in northwestern Polk, and was
tentatively placed in the Tampa. This has since been identified as
Suwannee Limestone. The same report (Stewart, 1959, p. 23)
also included in the Tampa Formation a "variegated (blue-gray
or blue-green and cream) silty sandy clay" which was thought to
overlie the limestone unit of the Tampa.
Figures 6 and 7 are geologic sections showing the formations
penetrated by wells in the Polk County area. These sections were
constructed from electric and sample logs. Data for the cased
sections in wells were interpreted from drillers' logs. In order to
identify the Tampa Formation in Polk County, it was necessary
to examine logs in southwestern Hillsborough County where the
Tampa Formation is better known and well defined. The corre-
lation of the Tampa Formation in the Polk County area is based
on electric logs from Hillsborough County.
In the Hillsborough County wells, the Tampa consists of a
limestone unit approximately 80-110 feet thick, and an overlying
sequence of interbedded, bluish to greenish gray sandy clays with
stringers of sandy limestone and calcareous sandstone which may
be weathered limestone remnants. The limestone unit overlies,
and is in direct contact with, the Suwannee Limestone. The clay
unit of the Tampa underlies limestones of the Hawthorn Forma-








REPORT OF INVESTIGATION No. 44


A --




to 112 ,-- o
too., .-- FOR &Y R >

I-..~o *(',... j 0 ........

i
i . ... ... .. ... ..--
-33 033 r0tr, ...


-----------------
300 Imt st .-I3
-ON 00
300O- .-aI I I0N3N
700rL --


2 -00- I





on Figure 5.


along lines A-A' and B-B'. Sections located


tion. The clay unit of the Tampa is cased-off in most wells. Some
of these limestone beds have been almost completely replaced by
gray, dense, very hard chert in wells west of Plant City, Hills-
borough County (Menke and others, 1961, figs. 51, 54). The inter-
bedded limestones and clays of the upper unit of the Tampa in
Hillsborough County appear to thin up-dip and merge with the
limestone unit. These units, along with very similar units of the
overlying Hawthorn Formation, appear to have been deposited in
a shallow littoral marine environment suggestive of oscillatory
stages.
The Tampa is readily traced across Hillsborough County and
into Polk County, and it is evident that the individual beds of this











FLORIDA GEOLOGICAL SURVEY


200-- o
SSUWANNEE
LIMESTONE
Stoo UNDIF
RIVER
SEA
LEVEL NGLIS




200 A


300-


400-


0 I 2 3 4 5 miles


I NGLIS

AVON PARK


7. Geologic sections along lines C-C' and D-D'. Sections located oi


C'



200


ITS -100

SEA
LEVEL

100


-200


-300


S400


-t0,
2100
too-

SEA
LEVEL




200-


300


S400-


500-


O -







Figure
Figure 5.


0'


a0
- 200


-100

SEA
LEVEL

-100


200


300


-400


-500


-600


?06


I= 4 _.5 miltS


____ _







REPORT OF INVESTIGATION NO. 44


ormation become thinner northward. This thinning is probably
.ue to deposition rather than to removal by erosion. In eastern
fillsborough and western Polk County the Tampa changes up-dip,
'rom a predominantly limestone sequence to a predominantly
clay sequence, and becomes the well-known "blue-clay" of local
drillers, the 50 feet of greenish-gray sandy clay of Carr and
Alverson (1959, p. 25), and the variegated sandy clay of Stewart
(op. cit.). Possibly this clay is also related or identical to the
"residual mantle of green calcareous clay" of Cathcart and
McGreevy (1959, p. 228), and to the "clay unit" of the Tampa
Limestone as described by Ketner and McGreevy (1959, p. 64).
The electric logs available do not indicate any significant
change in character in the rocks above the blue clay of the
Tampa, and it is believed that in Polk County these generally
constitute only the Hawthorn Formation.
To summarize, in Polk County the Tampa Formation is gen-
erally composed of a bluish- to greenish-gray, calcareous, locally
phosphoritic, sandy, shaley clay that contains lenses, fragments,
and occasional thin beds of white to gray sandy limestone. The
blue clay unit of the Tampa was found to be more extensive than
stated by Carr and Alverson (1959, p. 25). This unit underlies
the limestone members of the Hawthorn Formation in all but
local areas along the northern edge of that formation, and east
of the Lake Wales ridge.
The Tampa Formation ranges in thickness from about 10 feet
in well 805-155-2 to about 80 feet in well 752-150-1, although
possibly even greater thicknesses exist.
The blue clay in the Tampa Formation is important in the
hydrology of the area because it is the lower confining bed of
one artesian aquifer and the upper confining bed of another.
The interpretations of the Tampa Formation in the present
investigation tend to agree with those of Carr and Alverson
(1959, p. 21), postulating the existence of Puri's (1953b, p. 19-21)
Chattahoochee facies of the Tampa stage of the Miocene Series
in peninsular Florida.
HAWTHORN FORMATION
In Polk County the Hawthorn Formation consists of massive,
interbedded sandy limestones and sandy clays which are not
individually distinctive. The clays are soft, sandy, phosphatic,
and usually a gray to dark bluish- or greenish-gray. The lime-
stone beds are light-cream to yellow or tan, very hard to soft,






FLORIDA GEOLOGICAL SURVEY


very sandy, clayey, and phosphatic. The beds are really extensive
but not really identifiable or distinguishable. Some of the beds
appear to be nonfossiliferous but where the beds are fossiliferous,
they contain casts and molds of large marine mollusca, silicified
and phosphatized bones, and a few silicified shells. In mine pits
east of Lakeland, the invertebrate fossils occurred in definite
zones or beds that were traceable across the mine.
Generally the basal limestone units have been dolomitized and
are highly crystalline, hard, and resistant. This characteristic
shows on the electric logs as a zone of very high resistivity and
appears to be a more massive bed, as much as 20 feet thick. Along
the northern edge of the formation the limestones are more
highly weathered and earthy, and the dolomitic beds are less
pronounced. Thickness of the formation differs greatly over the
county, ranging from a few feet thick immediately north of the
Lake Parker area to about 160 feet thick in well 747-158-3 at
Bradley Junction. This is perhaps the greatest thickness in the
county.
The upper 2 to 10 feet of Hawthorn limestone were exposed
occasionally in 1954-55 during mining operations in the Saddle
Creek Mine just north of U.S. Highway 92 near Saddle Creek.
A number of sections were measured, described, and photographed
in these mines. Mining has since terminated in this location
and all of the sections described have been mined-out, buried, or
flooded. The upper surface of the limestone in these pits is us-
ually highly eroded and overlain by 1 to 6 feet of brown,
sandy, gritty clay. Locally the limestone is overlain by brown,
well-indurated, clayey, sandstone which, in places, fills the irregu-
larities on the limestone surface. In a few small areas the limestone
is overlain unconformably by lenses of white to dark-green, mas-
sive, dense, blocky clay. Both the clayey sandstone and the dense
clay are included in the Hawthorn Formation.
The limestones are sufficiently permeable to supply water for
domestic and small irrigation requirements, and locally they con-
tain well-developed solutional cavities which enable them to yield
large quantities of water.
The Hawthorn Formation overlies the Tampa Formation un-
conformably, and unconformably underlies sands and clays of
Miocene to Recent age.
UNDIFFERENTIATED CLASTIC DEPOSITS
Overlying the limestones of the county are sands, clays, clayey
sands and sandy phosphatic clays. The age of these materials
ranges from middle Miocene to Recent.






REPORT OF INVESTIGATION NO. 44


PHOSPHATE DEPOSITS
Over much of the area lying west of the northern unit of the
'.inter Haven ridge and the southern part of the Lake Wales
ridge, and generally south of the latitude of Polk City, the
iHawthorn Formation is overlain by sandy clays containing pebble
phosphate, which are in turn overlain by sandy clays and sands
that have been largely leached of their original phosphate con-
tent. In part, these phosphate-bearing beds are a weathered re-
siduum of the Hawthorn Formation, and in part constitute the
Bone Valley Formation generally considered to be of Pliocene
age.
North of the latitude of Polk City and west of the Lake Wales
ridge, outside of the general pebble-phosphate area, the limestones
are overlain by sandy clays which have variously been described
and placed in the Alachua, Tampa, and Hawthorn Formations by
Vernon (1951), Cathcart and McGreevy (1959), and Ketner and
McGreevy (1959), respectively. For the most part these sandy,
slightly phosphatic clays are not readily identifiable in the field
as to formation.
In the area generally east of Polk City, Winter Haven, and
Frostproof, and south of Polk City and Haines City, the lime-
stones are overlain by sandy, slightly phosphatic clays, and marls,
or by clayey sands. In general, these materials are less dense
than the phosphate-bearing clays in the western part of the
county. These clays function as a confining bed for the artesian
aquifers developed in the limestones of the county.
In the remaining part of the county, north and east of Haines
City, the limestones are overlain by generally less clayey and
more permeable marls and sands. In the north end of the Lake
Wales ridge and other parts of this area, the limestones are
overlain by relatively clean or only slightly clayey sands.
COARSE CLASTIC DEPOSITS
Overlying the clays in some areas of the county is a deposit
of clayey, poorly- to well-indurated, quartz sand which is gener-
ally white and very clayey in its lower portion and red to purple
to orange and less clayey in its upper portion. These sands are
micaceous and contain stringers and beds of discoid quartzite
pebbles. Bishop (1956, p. 26) describes these sediments as grading
downward into the Hawthorn Formation in Highlands County
to the south of Polk and as a deltaic unit of that formation. Pirkle
(1957, p. 21) describes them in Alachua County as a marine deposit
of probably Pleistocene age. Ketner and McGreevy (1959, p. 71-






FLORIDA GEOLOGICAL SURVEY


73) discuss this unit, and assign it to the late middle Miocene or
the early late Miocene.
The unit is very thick in the Lake Wales ridge. However, the
unit appears to be absent from well 811-138-3 and others along
this ridge. It is found in many lowland locations, though it is
most prominent in the ridge areas. For example, remnants of the
unit constitute the many low hills and knobs along Fla. Highway
33 in the area north of Polk City.
The unit is used locally as a source for small domestic water
supplies and is a part of the nonartesian aquifer. It is of consid-
erable importance to the hydrology of the county because of the
high storage capacity available and resultant recharge to the
underlying limestones.
The entire county is blanketed by unconsolidated quartz sands,
on which the present soils have developed. These deposits have
been customarily assigned to the Pleistocene, as marine terrace
deposits. Recently, however, Altschuler and Young (1960, p. 202-
203) have established that the surface sands in the Lakeland
Ridge and the phosphate-mining area of west-central Polk County
are "mainly an insoluble residue of lateritic alteration of the Bone
Valley formation, and not a transgressive Pleistocene deposit."
The observed lack of marine terraces, shorelines, or related topo-
graphic features at supposed terrace elevations in this part of the
county strongly supports these findings.
Some terraces do exist in the eastern part of the county.
These are best developed and preserved on the east flank of the
Lake Wales ridge, south and east of the city of Lake Wales.

STRUCTURE
The rocks in Polk County dip at low angles and thicken to the
southeast, south, and southwest, from the north-central part of
the county around the southern end of the Ocala uplift. This
broad dome, or regional anticline, is developed in the Tertiary
formations of northern and central Florida, and it has been
mapped and discussed in considerable detail by Vernon (1951,
p. 47-58, and plate 2).
The Ocala uplift is an elongate dome whose long axis trends
northwest-southeast on an approximate line from Cross City,
Dixie County, to Haines City in northeastern Polk County. Ac-
cording to Vernon (1951, p. 53) the structurally highest point
on the crest of the uplift is in eastern Citrus and Levy counties.






REPORT OF INVESTIGATION No. 44


Vernon's structure map of the Inglis Member (now Formation)
(1951, pl. 2) shows this high point to be outcrops of the Avon
Park Limestone at altitudes of approximately 50 feet above sea
level.
Prior to the work of Vernon (1951, p. 47-52), fracturing and
faulting of the rocks in Florida had not been recognized. He at-
tributes the development of these features to the compressive
forces, and the relief of tensional stresses, associated with the
formation of the Ocala uplift during the late Tertiary. Vernon
states (op. cit., p. 50) "-The poorly consolidated sediments com-
posing Tertiary rocks of Florida favor adjustments to strain by
step fracturing rather than by bending.
Because the tensional and shearing stresses would be greatest
over the uparched area of the Ocala uplift fracturing developed
by them would tend to occur in groups along the axis of the fold
and to indicate the direction of greatest stress and of the
elongation of the arch. If these joints are tensional they would
tend to die out with depth because stretching is greatest toward
the outside and least toward the inside. Available geologic data
indicate that only tensional fractures are present in the area
and that these are shallow."
The present investigation shows that the crest of the Ocala
uplift in north-central Polk County is within a few feet of being
as structurally and physically high as the crest in Citrus and Levy
counties. Figure 8 is a map of the geologic structure in Polk
County, shown as contours on the top of the Inglis Formation.
The contact of the Inglis Formation and the overlying Williston
Formation is conformable and hence represents an un-eroded
horizon which is suitable for structural studies. Structural re-
lationships are also shown by the geologic cross-sections in figures
6 and 7.
The configuration of the Inglis surface is the result of (1) the
highly irregular surface of the underlying Avon Park Limestone,
because the Inglis is relatively thin and did not fill in pre-
existing irregularities, (2) erosion of the overlying rocks down
to the surface of the Inglis, and (3) faulting due to uplift, after
the Inglis was deposited. The northwest-southeast lineation, and
the less prominent northeast-southwest lineation in the county
align with the structural trends established by Vernon (1951,
pl. 2). These features are the result of deep erosion of the Avon
Park Limestone prior to deposition of the Inglis Formation.
The parallelism of the hills and valleys strongly suggests that






FLORIDA GEOLOGICAL SURVEY


Figure 8. Structure-contour map on top of the Inglis Formation.


this erosion was controlled by fractures which parallel the axis
of the Ocala uplift. The work of Vernon (1951, pl. 2) suggests
that many of such fractures may be faults developed parallel
to the crest of the uplift. These faults are the parallel, step-type
faults. The vertical displacement along most faults is 60 feet or
less. Irregularities in the structure contours in figure 8 suggests
that numerous fractures and faults of small vertical displacement
exist in the county, but the available geologic control is inade-
quate to define them.
During this investigation faults were observed in limestone
of the Hawthorn Formation at mine pit exposures in the Lake-
land area. Two of these faults, mentioned by Stewart (1959,
p. 24), are located 0.15 miles north of U.S. Highway 92 and 0.45
miles west of Saddle Creek (fig. 2). The maximum vertical
displacement of beds in one fault zone is 1 foot. Four separate
fractures occur in this zone, which is the site of a solutional






REPORT OF INVESTIGATION No. 44


cavern from which a spring is flowing. A second fault zone is
located about 150 feet to the east and the vertical displacement
along this fault is 6 feet. A spring also flows from a cavern
developed in this fault, but the flow is at water level in the ditch
and is less spectacular than in the first zone described. Normally
water levels in the Hawthorn Formation are about 20 feet above
the top of the limestone in the vicinity of the faults. However,
water levels were temporarily lowered by continuous pumping
from this excavation for mine water supplies, and to keep the
active pits dry.
Another fault was observed in this area, approximately 1,000
feet southwest of the faults described above. The fault (zone?)
strikes N30W, with approximate dip of 80NE. The southwest
side of this fault was downthrown approximately 6 feet. The fault
appeared to be a reverse fault, both from the apparent dip of the
fault plane into the upthrown block and the slight dragging of
beds on opposite sides of the fault.
The existence of the faults observed in mine workings could
not be detected in the subsurface except by a long line of test
holes spaced a few feet apart, and then only if the beds contained
identifiable distinct lithic or faunal zones which could be used
for correlation across the faults. The exposures in mine pits con-
clusively establish the existence of such faults and their relation-
ship to the occurrence of solutional caverns and the occurrence
and movement of ground water.

HISTORY OF STRUCTURAL MOVEMENTS
Vernon (1951, p. 62) states that the movements which formed
the Ocala uplift are post-Oligocene and pre-Miocene in age. He
also indicates that some structural movements may have con-
tinued irregularly throughout later epochs. One of the criteria
that Vernon used for dating the uplift was an apparent lack of
Miocene sediments over the structural high. However, Cathcart
and McGreevy, Ketner and McGreevy, and Carr and Alverson
(all 1959) each report the presence of Miocene sediments over
the crest of the uplift. Carr and Alverson (1959, p. 66) indicate
a late Oligocene time for the inception of the uplift, with renewed
movement along a major fault on its crest in Polk County at the
close of Tampa time.
Several lines of evidence collected in the present investigation
strongly suggest that the Ocala uplift started prior to the depo-
sition of the rocks of the Ocala Group:






FLORIDA GEOLOGICAL SURVEY


(1) Pronounced thickening of the Inglis and Williston Fo,-
mations in present structural lows. This strongly indicates that
the faulting was recurrent through much of Eocene time. Some
of the structural lows are probably downthrown fault blocks.
(2) Pronounced thinning of the Inglis and Williston Forma-
tions over present structural highs, and particularly over the crest
of the uplift in the north-central part of the county.
(3) In a number of places all of the individual beds or units
of the Crystal River Formation and the Suwannee Limestone
thin markedly over structural highs and thicken in lows. This
change in thickness is particularly true in the Hillsborough
County and western Polk County and in northern Polk County.
Such thinning and thickening is depositional rather than ero-
sional.
Thus, it is believed that some areas which are presently struc-
tural highs associated with the Ocala uplift were also structural
highs during deposition of the Ocala Group and later rocks, and
that movements which produced the Ocala uplift as presently
known had their beginnings during the Eocene. The data also
indicate that some movement occurred as late as Miocene time.

SOLUTION FEATURES
The limestones of Polk County contain many inter-connected
openings, ranging from a fraction of an inch to many feet in size,
which are the result of solutional removal of the limestone by
circulating ground waters. Small cavities have been observed in
pieces of limestone that were recovered during well drilling from
depths greater than 1,300 feet below land surface. Many large
cavities, ranging from 1 to 40 feet or more in height, have been
reported by local well drillers. Such openings greatly increase the
water-transmitting ability of the rocks and hence the yield of
wells. Knowledge of these solutional features, therefore, is con-
sidered essential to the understanding of the hydrology and
geology of the limestone aquifers in the county, and in the re-
mainder of the state as well.
Limestone (calcium carbonate) is slightly soluble in pure
water. However, water which contains a small amount of acid will
dissolve limestone much more readily. Rain reaching land surface.
has absorbed carbon dioxide from the atmosphere, and the ga;;
and water combine to form carbonic acid. During infiltration o:!
the surface and percolation downward through the soils the water






REPORT OF INVESTIGATION NO. 44


A ill absorb and combine with additional quantities of carbon
c(oxide from the soil. When the weak acid is in contact with
I mestone for a long period of time, very large amounts of the
I~)ck will be dissolved. Many factors influence the amount and
rate of solution, but two of the most important ones appear to be
tne amount of contact area and the length of time in which
the water and limestone are in contact.
The solution of limestone by circulating water is greatly
facilitated by, and localized in, fractures, joints, and bedding
planes in the rock because water moves more freely through these
relatively large, continuous openings than it does through the
original or primary pore spaces of the rock. Solution and removal
of limestone is, therefore, more effective and rapid along the
fractures, joints, and bedding planes and is most effective at their
intersections. An extreme development of solutional features along
fractures occurs along fault zones in limestones of the Hawthorn
Formation in the Saddle Creek Mine, east of Lakeland. These
faults have only 1 to 6 feet of vertical displacement. One cavern
developed along the fault zones measured 8 feet deep, and another
measured 3 feet deep. These are minimum depths, because ac-
curate measurements could not be made. Both caverns were 2 to
4 feet wide and were confined to the fault zone. The limestone
elsewhere in the exposure is relatively devoid of smaller solutional
tubes, cavities, and honeycomb as noted in the older limestones
in table 4. Though fractures provide the avenue of easiest and
greatest solutional excavation, and hence the largest caverns, the
primary porosity in most of the limestones of this area is suffi-
ciently high to permit some passage of water in response to nat-
ural gravity flow.
In inter-fracture areas, water moves much more slowly; hence,
the quantity passing a given point per unit of time is less, and
solutional excavation is much slower. Small primary pore spaces
slowly enlarge and coalesce and the limestone develops a fine-
textured, honeycomb or spongiform appearance. This type of solu-
tion is speeded by the removal of the shells and tests of marine
invertebrates, particularly those of large mollusca and echinoids,
leaving relatively large open pores. Honeycomb development was
also observed on many random pieces of rock recovered during
drilling operations in other wells.
With the continual movement of ground water and solution,
extensive honeycomb and tubular networks develop simultaneously
with major cavern development along fractures, where the rate








TABLE 4. Solutional features penetrated by wells in Polk County
(e, estimated)

Altitude of ApPrreat
USOS FGL Altitude of bottom of height Probable
well well lad in feet feature in of feature Geologic
number number above rol feet below Inu in feet Type of feature Unit Source of data Reimarks


739-121-4
741-139-2
741-140-1
741,141-1
742-129-1
743-157-1
744-143.1
745-147-1
745-148-3
745-158-1
745-158-8
745-159-2
746-143-1
746-148-1
748-160-1
747-114-1
747-133-2
747-187-1
747-142-2
747-143-1
747-144-2
747-144-3
747-153-2

748-131-1
748-144-2
748-145-1
748-148-1
748-148-4


W-68



W-981



W-4123
W-2304

Wgi-35

W-1726
W-978
W-1110

W-912
Wgi-348
Wi-1008

Wgi-1012
Wgi-342
W-2139
W-1050
W-995


748-148-5 W-639

749-144-1 Wgi-364
749-145-1 Wgi-471
749-145-2 Wi-378


62
149
147
132
104
140
180*
129
138
163
137
160*
223w
149
153
61"
128
147
160
182
216
206
167

243
212e
210
110
110

115

232"
217
231


733
782
+71
273
746
100
+2
+114
+108
-76
689
705
605
116
667
691
677
206
500
812
835
640
643
664
649
113
639
646
1,060
632
612
277
618
630
637
648
669
680
634
760
10


15
7

S
6


6
5
5

2
2
7
18
6
10
5
2
33

2
3
39
?
22
3
8
6
24
7
31
4
2
3
2
4
7
4
4
10
66
20
36


Honeycomb Avon Park
Cavern do
do Hawthorn
do Crystal River
Cavern fill Avon Park
Cavern Hawthorn
do do
do do
do do
do Tampa
do Avon Park
do do
Porous zone do
do Tampa
Cavern Avon Park
do do
do do
Porous zone Hawthorn
do Avon Park
do do
Cavern do
Porous zone Avon Park
Cavern do
do do
do do
Cavern fill Suwannee
Porous zone Avon Park
do do
Cavern fill Lake City?
Cavern Avon Park
do do
Porous zone Crystal River
Cavern Avon Park
do do
Honeycomb do
Cavern do
do do
do do
Porous zone do
Cavern fill Avon Park
Honeycomb Hawthorn


FOS geologic log
Owner
Driller
Owner
Driller's log
Owner
Driller
Owner
do
Driller's log
do
do
Electric log
Driller
Driller's log
do
Driller
Electric log
Driller's log
do
Owner
Driller's log
do
do
do
do
do
do
do
do
do
Electric log
Driller's log
do
do
do
do
do
do
Driller's log
do


Additional asall cavities re-
ported above this







Honeycomb?
"Loae of cuttings"


Honeycomb?
"iUme with crevices"
"Brown lime with crevices"
Size not given, depth to top of
cavern
"Brown lime with crevices"
"Break"
"Big water"
"Green shale and sand"
"Los of cuttings"
"Loss of cuttings-water"
"Brown lime and sand"
"Break"
Occurs in interval 815-822 ft
Honeycomb?




"Brown lime rock crevices"
"Lime shells and sand"






749-149-1
749-158-1
749-159-1
750-142-3
780-145-1
750-148-1


Wgi-10J4
Wgi-344
Wgi-485
W-41


750-151-3 W-1395
750-168-1
751-140-1 Wgi-337
761-141-1 W-928
751-145-1 W-974
751-145-2 Wgi-363
761-145-3 Wgi352
751-146-2 W-1006
761-148-1 W-2856
751-155-2 W-2538
752-1844 Wgi-1019
752-141-3 W-4189
782-142-1
782-142-7 W-1111
782-145-3 Wgi-355
782-145-4 Wg-859
752-146-3 Wgi-460
752-146-4 W-1113
752-150-1 -
752-201-2 Wgi-1020


752-201-3 Wgi-1021

753-133-1 Wgi-1023
753-134-2 W-500
753-143-1 W-2151
753-145-5 Wgi-167
763-149-2 W-2425
753-149-3 Wgi-371
753-150-3 W-945


126
100e
155e
1760
190e
85



136
151
135
163
176
2120
186*
171
113
183
201
144
171
159
176
167
209
196
125e
120e


1200

183
242
151
162
101
122e
110


530
243
292
600
44
522
524
407
665
2,467
4,455
641
4
689
693
487
606
615
585
507
485
516
233
572
384
551
665
615
53
456
507
524
77
520
591
734
565
620
177
626
617
583
569
448
342
329


50
3
1
5
15
3
2
2
24
62
37
2
5
68
4
8
7
22
11
46
18
1ii
15
11
5
107
112
71
15
90
50

8
68
1
4
35
5

43
12
32
20
20
18
0


do
Porous zone
do
Cavern
Honeycomb
Cavern
Gravel
Cavern
Cavern fill
Honeycomb
Porous zone
Cavern
do
Porous zone
Cavern
do
do
Porous zone
do
Honeycomb
Cavern
do
Cavern fill
do
Cavern
Honeycomb
Porous zone
do
Honeycomb
Cavern fill
do
Porous zone
do
do
Cavern
do
Porous zone
Cavern
Cavern fill
Porous zone
Cavern fill
do
Porous zone
Honeycomb
Cavern fill
do


Avon Park
Hawthorn
do
Avon Park
Hawthorn
Avon Park
do
do
do
Oldsmar
Lawson
(Cretaceous)
Avon Park
Hawthorn
Avon Park
do
do
do
do
do
Avon Park
do
do
Williston
Avon Park
Williston
Avon Park
do
do
Suwannee
Avon Park
do
do
Tampa
Avon Park
do
do
do
do
Crystal River
Avon Park
Avon Park
do
do
do
Inglis
Williston


do
Electric log
do
Driller's log
Owner
Driller's log
do
do
do
do
do
do
Owner
Driller's log
do
do
do
do
do
Driller's log
do
do
do
do
Owner
Driller's log
do
do
do
do
do
do
Electric log
Driller's log
do
do
do
do
do
do
Driller's log
do
do
do
do
do


Cavity fill?
"Cave-in"
"Water, sand, heavy flow of
water"
"Porous limestone with sand
lenses" (cavity fill)

"Brown lime with cavities"


"Crevices"
"Crevices"


"Sand"; at top of Inglis?
"Clay with silt"
At top of Inglis?
"Brown lime-crevices"
"Brown lime with crevices"
At top of formation?
"Water sand"
"Shells and water sand"
"Hard brown lime, crevices in
lower section"
At top of Suwannee?
"Hard lime rock with small
openings"

"Vicksburg lime, small open-
ings, no returns"
Well 25 ft east of well above
"Sand coming into well"; at
top of Williston?
"Fu of crevices"
"Sand"
"Water, sand, and gravel"
"No cuttings returned"
"Brown sand and soft lime
rock": at top of formation?
"Lime rock and sand"









TABLE 4. Solutional features penetrated by wells in Polk County (Continued)
(e, estimated)


Altitude of AnPtrent
USG8 FCO Altitude of bottom of height Probable
wellwe ell Ld in feet feature in of feature (Veologic
number number above isal feet below unl in feet Type of feature nitn source. of datl0a RelarkL


763-150-5 W-3304
753-151-2 W-O 5
754-144-1 W'gi-353
7M4-1502 -
754-152-2 W-1801
754-152-3 W-1802
751-1I6-1 W-110
7.l 54-1- W-2098



756-130-1 Wi-1031
750-133- Wgi-103
7856-156-1 Wxi-330
767-133-1 -
757-133-2 WgiO-3i


767-140-1 W-952
757-182-1 W-1441


767-153-2
757-163-3
757-154-3
757-154-5
7W8-139-1
758-1453-1
758-152-3
768-1683-


785-154-1

758-155-2
759-134-1


Wgi-340
W-2241
Wgi-347

Wgi-464
W-1864
Wgi-365
Wgi41

Wgi-338
Wgi341


124
119
122
IiW
147
140
130
200



95,
118
215
185
142

122
117


128
122
1670
234
142
145
1200
123
130
128

258
204


018
510
550
+23
928
009
039
?

502
235
82
506
545
233
332
540
99
275
321
457
31
272
473
552
532
470
480
390
237
465
527
124
225
422
553
491


7
4
33
2
7
8
50
2

10
5
2
G
25
30
85
2
2
7
8
2
2
40
8
0
4
110
40+
2
2
79
7
6
8
11
?


Porous zone
Cavern
Porous zone
Cavern
Ioneycomb
do
Porous zone
Cavern

Cavern and
cavern fill
Cavern fill
Cavern
do
do
Cavern fill
do
Cavern
Porous zone
do
do
do
do
Cavern
do
do
do
do
Cavern fill
Cavern
do
do
Porous zone
Cavern
do
do
Porous zone
Cavern


Avon Park
do
do
Taiiipa
Avon Park
do
do
Sitwanne

Avon Park
Inglis
Crystal River
Avon Park
do
Inglis
Avon Park
Avon Park
Crystal River
Avon Park
do
do
Suwannee
Crystal River
Avon Park
do
do
do
do
do
Inglis
Avon Park
do
Suwannee
Williston
Avon Park
do
do


Driller
Driller's log
do
do
do

do
rdo
do
do
do
do
Driller's log
Electric log
do
do
do
do
Driller
Driller's log
do
do
Tenant
Driller's log
Driller
Driller's log
do
do
do
do
do
do
do


"No cuttings returned"
"Brown lie with open ere-
vice"s"
At top of Lake City?
"Changed by solution action,
likely cavernous"
Exact depth not reported.
cavern occurs in theinterval
from 110 to 158 ft
"Water, sand. gravel, and
small cavern"
"Sand"; at top of Avon Park?


"Coral and wlite sand"; at
top of Avon Park?
"Coral and white sand"




Reported by a local driller
"Cavern, gravel-filled"

Present when drilled
"Lime and water sand"
Full depth not measured
"Sand"
"Brown lime. rock with cre-
vices"
At top of Crystal River?
At top of lagliTs
"Crevices-big water"
Apparent diameter not given


1







759-143-2
759-156-1
759-159-1
759-200-1

759-201-1
759-201-2
800-135-1
800-153-3
800-156-2
800-156-8
800-157-1l

800-159-1
801-138-2
801-189-2
801-139-3
801-146-1
801-200-3


801-201-3
802-134-1
802-136-2
802-136-8
802-143-1
802-143-2
802-143-
802-149-4


802-150-8
802-151-19
802-152-10
802-154-2


W-1445
W-2153
W-2129
W-2954

W-632
W-6833
Wgi-801
W-724
m- z

W-2015

W-3420
W-4493
Wgi-1042

Core i2





Wgi-1043
W-3305
W-3306
W-4307
W-3633




W-3422


136
155
143
136e

132
135
170
119
139
132
204

146
128
139
149e
150e
135e


134
130
193
'204
147
144
145
130


119
+21
110
142e


511
521
526
552
556
+86
+76
+60
255
530
535
326
341
611
581
138
516
568
+13
52
392
281
20
310
320
412
597
26
412
417
574
65
81
435
+10
672
497
433
820
-0
5
+45
?


?
37
7

37.
4
3
2
2
10
5
6
2
15
20
20
50
12
11
4
5
10

5
10
7
2
10
55
3
2
6
14
7
4
11
12
8
5
5
8
?


Cavern and and
Cavern-no sand
Porous zone
Cavern
Porous zone
Cavern
do
do
do
Porous zone
Cavern
do
do
Cavern fill
Porous zone
do
Cavern fill
Honeycomb?
Cavern?
Cavern fill
Cavern
Cavern fill
Porous zone
Cavern
Cavern
Cavern fill
Cavern
do
Porous zone
Cavern
do
do
do
Cavern fill
Cavern
do
Porous zone
do
do
Cavern and fill
Porous zone
do
do
Cavern


do
do

do
do
Hawthorn
do
Tamps
Avon Park
do
do
do
do
do
Crystal River
Avon Park
do
Suwannee
Hawthorn
Avon Park
do
Suwannee
Avon Park
do
do
do
Suwannee
Avon Park
do
do
Crystal River
do
Avon Park
Suwannee
Avon Park
do
do
do
Tamps
Suwannee
Hawthorn
7


do
do
Driller's log
do
dj
do
do
di
Electric log
Driller's log
do
do
do
do
Driller
do
Driller's log
do
Observation
Driller's log
Driller
Driller's log
Driller
Observation
Driller's log
do
do
Driller
Local driller
Driller
do
Driller's log
do
do
do
do
do
do
do
Electric log
do
Observation.
Owner


"Three or four 1- and 2-foot
cavities"
Probably not bottom of well
-depth not given in log
"No cuttings returned"

At top of Suwannee?
At top of Avon Park?
"Crevices-hard rock"
"Sand in bottom of this
stream"
"Brown rock with some sand"
"No cuttings returned"
"Lost circulation"
"Sand"
"Water"
Dark organic clay, with small
clusters of satin-spar
"Sand and gravel"
"Lost cuttings"
Top of cavity-depth not re-
ported
At top of formation?
"Sand and mud"

"No cuttings returned"



"Blue mud"
"Break"; at top of formation?
"No cuttings returned"
"Series of caverns"
"Several openings with wa-
ter"; st top of formation?
"Opening of mud and odor of
gas"; at top of Lake City?
At top of Suwannee?
At top of formation?
Loss of cutting
Depth to feature and height
Snot given, probably in bot-
tom of well







TABiM 4, Solutional features penetrated by wells in Polk County (Continued)
(e, estimated)

Altitude of Apparent
US08 FOS Altitude of bottom of height Probable
well well lad in feet feature in of feature Geologic
number number above mel feet below nul in feet Type of feature Unit Source of data Remarks


802-1564 -
802-167-7
802-167-16 W-4163
802-158-1 W.2767
803134-1 W-458
803-138-1 -
803-137-1 W-1416

803-1451 W-3444
803-145-2 W-2925

803-146-2 W-2720
803-147-4 W-872


803-147-12
803-153-12
803-153-14
803-15-24
808-153-28
803-154-31
803-164-33
803-15614
803-158-1


804-143-1
805-136-1
805-1364
805-186-6


Wgi-1051


W-3425
W-424
W-1800
Wgi-805
W-24


W-4412



Wgi-1053


138'
210
191
193
101I
174
104

145*
155

163
169

141
124'
125
124
127
138
141
148
218


i33e
175e
202
190'


+14
+10
40
471
523
630
459
418
298
326
. ?
+13
.-0
-62
?

476
+61
+27
67
0
12
429
442
402
524

19
25
+17
92


Cavern


do
do


do
do
do
Cavern fill
Cavern
do
Porous sone
Cavern
do
Porous zone
do
Honeycomb

Cavern
do
do
Cavern fill
Cavern
do
Porous zone
Cavern
Porous zone
Cavern fill

Cavern
Cavern fill
do
do


Buwannee
do
Suwannee
Avon Park
do
do
do
do
do
do
7
Hawthorn
do
Suwannee


Avon Park
Hawthorn
do
Suwannee
do
Suwannee
Avon Park
do
Avon Park
do

Hawthorn
Crystal River
do
deo


Driller
do
Owner
Driller's log
do
do
FOB Geol. log
Tenant
Driller's log
do
do
do
do
do
do

do
do
Driller
Observation
Driller
do
Driller's log
do
Driller's log
FOS Geol log

Driller's log
Owner
do
Driller's log


At top of formation?
Depth not given, probably in
bottom of well


"Fine quarts sand and finely
powdered limestone"
Present when drilled
"Sand"
"Lot cuttings" and "Honey-
comb chunks"
Depth and sie not given-
probably in bottom of well
"No cuttings returned-soft
honeycomb"
"No cuttings returned"
"No large cavities-only 4- to
6-inh openings." Depth In-
tervals not reported.

"Open cavern and loss of cut-
tngs"
Sand-filled honeycomb

"Lost cuttings"
Size not given
"Occsionl crevice of cavern"
"Quarts pebbles, peat, porous
limesone, blue clay, and py-
rite"
"Sand, dry, under rock"; at
top of formation?
"Sand pocket"; at top of for-
mation?
"Top of sand pocket-not
drilled into"; at top of Wil-
liston?






805-143-2 W-393
805-147- -
805-149-2 W-4188
805-158-4 W-4018
805-154-8 Core fl



805-155-2 W-3766
805-156-2 W-3769
80-169-1 W-3312
806-187-2 W-3207
806-187-3 W-3799
806-17-4 W-3802


806-187-5 Wgi-109


806-187-9 W-402
806-138-1 W-464
806-156-2 W-3771
807-18-1 -
807-154-4 W-3883
807-157-2 W.4884
807-159-1 Wgi-1089
807-201-1 W-2774
808-157-1 -
808-200-4 Wgi-1063
809-185 -
809-147-1 W-4275


156
1550
159
182
180



135
1836
206
178
145
143


133


178
129
136
181
135
154
1750
143
1660
199
155
135


- 143
- 151


502
347
426
+48
382
399
644
604
664
+43
+56
54
+34
360
290
338
82
184
372
419
201
317
489
512
484
+41
119
417
426
+8
05
+69
506
+1
5
376

377
72
824
329
334


2
20
2
19




9
2
4
43
10
1+
10
3
5
2
8
4
20
4
6
10
33
7
15
2
75
1
2
10+
14
2
6
18

1+
5
1
1


Cavern
do
Porous zone
do
do
do
Cavern fill
Porous zone
Cavern fill
Cavern
Cavern fill
Porous zone
Cavern
Porous zone
Cavern fill
Cavern
Cavern fill
Cavern
Porous zone
Cavern
Porous zone
Cavern and fill
Cavern
Cavern fill
do
Honeycomb
Cavern
do
Honeycomb
Cavern
do
Cavern and fill
Porous zone
Cavern
Cavern fill
Cavern

Porous zone
Cavern
do
do
d3


Avon Park
do
do
Suwannee
Avon Park
do
do
do
do
Suwannee
Tamps
Suwannee
Hawthorn
Avon Park
Avon Park
do
Crystal River
Avon Park
do
do
do
do
do
do
do
Suwannee
Crystal River
Avon Park
do
Suwannee
do
do
Avon Park
Crystal River
do
Avon Park

do
do
do
do
do


do
Driller
Driller's log "No cuttings returned"
do !Loot circulation"; at top of
Formation?
Driller's log "Loet.all circulation"; at top
and observation of' formation.
Driller's log Do
do "Sand pocket"
do "Lost all circulation"
do "Sand coming into hole"
Observation
do At top of formation.
Driller's log "Honeycomb"
do
do "Water and sand"
Driller's log "Soft sand"
do
do "Sand"
do
do "Creviced brown lime"
do
do "Cuttings pass off into sub-
surface streams"
do "Cavity with coarse brown
sand
do
FGS GeoL log "Sand"
do "Sand with some limestone
fragments"
Observation "6- to inch cavities-e8 to
95 feet"
Driller
Driller's log
Driller
do
Driller's log Depth to cavity not given-
probably at bottom of well
Driller 10-ft cavern, then into clean
sand
Driller's log "No cuttings returned"
Driller At top of formation?
do "Sand"
Observation (Dolomite pebbles up to 1-
inch diameter recovered
from floor of cavern)
do "Honeycomb"
Driller's log At top of formation?
do
do
do


Pu





n
'U :






Ct
I '










<0
A'

A'











01







TABL 4. Solutional features penetrated by wells in Polk County (Continued)
(e, estimated)

Altitude of Apparent
1808 FGO Altitude of bottom of Probable
well well Ild in fees feature in of feature Geologie
number number above mel feet below mel in feet Type cf feature Unit Source of data Remarks

810-147-1 161 344 1 do do do


810-155-1 W-3866
811-188-3 W-4199
811-149-1 25
813-139-1 Wgl-1068

813-139-2 -
813-149-1 W-S(04
813-201-1 W-5352


814-138-1 -
814-139-1
815-139-1 Wgi-1009
815-157-1 W-3810
815-157-2 W-3839


816-146-1



817-139-2
817-150-1
818-140-1
818-151-2


W-4680 128



209
Wgi-1073 159
Wgi-1074 218
114


349
372
+19
614
305
315
447
347
4689
649
298
20
49
95
105
130
140
116
361
394
+65
11
1434
21
31
36
41
40
17
261
264
276
94
287
216
602
602
+34


1
3
2
2
60
5

7

2
5
10
1
91
123
5



1
3

51
13


1



13


10
5
1+
2+


do
do
Porous zone
do
Cavern
Cavern fill
Porous zone
Cavern fill
do
do
do
do
do
Porous zone
Honeycomb
Cavern
do
do
Cavern fill
Porous zone
Cavern
Porous zone
Cavern
Porous zone
Cavern
Hon ecomb
Cavern
Cavern fill
Cavern
do
Honeycomb
Cavern fill
Cavern
Cavern fill
Cavern
do
Cavern fill
Cavern


do
do
Suwannee
Crystal River
Avon Park
do
do
do
do
do
do
do
do
Williston
Inglis
Avon Park
do
do
do
do
Crystal River
Williston
do
Inglis
do
do
do
do
do
do
Avon Park
do
do
Avon Park
do
do
do
do
Crystal River


do
do
Electric log
do
Owner
do
Driller's log
Driller
do
do
do
Observation
do
Observation
do
do
do
Driller
Driller's log
do
Observation
do
do
do
do
do
do
do
do
Driller
Observation
do
do
Driller's log
do
do
Driller
do
Owner


"Sand"
"No cutting returned"
"Sand bed'
Do
Do; at top of Lake City?
Do
Quarts and cavity fill
No Cutting returned
Few cuttings returned


Limestone and sand beds
"No cuttings returned"
"No cuttings recovered"
Do
Small cavities
With quartz sand
Sand eavity-s prevented fur-
ther drilling
Size not reported; at top of
formation?
No cuttings recovered
Quartz sand-prevents drill-
ing
"Sand"


"'Sand"
At top of Williston?







818-155-2 Wgi-1061


13 Filled caverns
B Cavern
1 Cavern fill


Ingis
do
do


Dnller
do
do


"iUlwoman A .-.. .:.";
- top of formation?
"Sand and muck"


108o





FLORIDA GEOLOGICAL SURVEY


of development is much faster. Tributary flow thus becomes es-
tablished in an elementary pattern, controlled by fractures, and
the cavern system is enlarged and extended with time, much as
surface drainage systems are developed. This process progressively
increases the water-transmitting ability of the limestones.
As the solutional caverns become larger the roofs, in some
instances, may slowly become incapable of supporting the over-
lying materials and eventually collapse. If the collapse extends
upward to land surface, a sinkhole is formed.
Obviously cavern systems functioning as ground-water con-
duits or drainage systems must have a terminus, or point of
discharge. In artesian aquifers, such as those in this- area
(Stewart, 1959), the cavern systems will not discharge at land
surface unless land surface is below the piezometric (pressure-
head) surface of the aquifer concerned. In such discharge areas,
concentrated flow at land surface, as artesian springs, will occur
where the confining beds are breached. It is likely that most
of the discharge of cavern systems of Polk County occurs through
the multitude of artesian springs in Hillsborough and other ad-
jacent counties to the south and southwest. The only significant
artesian spring in Polk County is Kisqengen Spring, southeast
of Bartow. The so-called "Ft. Meade Spring," just east of the
town of Ft. Meade, is actually a man-made pool fed by a flowing
artesian well.
Diffuse discharge at a low rate probably occurs as general
upward leakage through confining beds in areas where the arte-
sian head is great, and confining beds are not visibly breached.
In Polk County such an area probably exists over much of the
valley floor of the Kissimmee River below Lake Kissimmee, and of
the Saddle Creek-Peace River system below U.S. Highway 92,
east of Lakeland.
CAVITIES
During this investigation data was compiled on open cavities,
honeycomb zones, and zones in which drill cuttings were lost at
depth in the limestones of the county. Beds of unconsolidated
quartz sand and similar sands encountered in the bottoms of
open caverns are all interpreted as cavity fillings, because such
deposits are not known as regular primary sedimentary deposits
in the rocks of Tertiary age in central Florida. Such deposits,
along with the other solutional features, are tabulated and pre-
sented in table 4. The locations of these wells and the altitude of
the base of the deepest feature encountered are shown in figure 9.






REPORT OF INVESTIGATION NO. 44


i. 9. Ma, .w. t- h location o~ \ells pen-.tatn sou.o, fet re
The r.da .of o n featue n te h ,

cry: a .-,, Avon P ; .Li.... i .... te se totl
t I ,--Z7 ^ FR ..STPR o0,




the /s n epne an of solutional fear h h
/ POLK COUNTY


Figure 9 Map showing the location of wells penetrating solution features
in the limestones

The preponderance of solutional features in the harder, more
crystalline, Avon Park Limestone is evident, and these total 65
percent of all solutional features recorded. Many of the wells
shownn table 4 do not penetrate the Williston and Inglis Forma-
tions and the Avon Park. Thus the number of solutional fea-
tures in the Avon Park may actually exceed the proportion indi-
cated. The table includes data from 190 wells and it records 274
separate features. It is believed that if detailed drilling logs were
available from all Wells in the county, the actual number of wells
which penetrate solutional features would be vastly more than
the wells now tabulated. However, such logs are available for less
than 400 of the more than 1,300 wells inventoried during this
investigation (Stewart, 1963, table 1).
A number of general observations may be made from figure 9:
1. Multiple zones of cavern development, at different altitudes,
exist in the same local area, as in the area west of Lake Hancbck.






FLORIDA GEOLOGICAL SURVEY


2. Locally the data show a definite correlation of altitude of
cavern zones, as in the area immediately west of Lake Buffum
at -650 msl, and in the area southwest of Lake Parker at -550
msl. These zones may be part of an integrated cavern system.
3. Four wells (750-148-1, 754-152-2, 747-137-1, and 741-139-2)
penetrated cavern systems or solutional features at depths in
excess of -900 msl; one of these (750-148-1) penetrated a honey-
comb zone at -4,455 msl.
4. Numerous solutional features exist at altitudes above msl,
particularly in northeastern Polk County.
5. Caverns have developed in areas where the limestone is
deeply buried, as in the southwestern part of the county.
6. In general, the caverns of the Lake Wales ridge are at
shallower depths below sea level than those of other parts of the
county in the same latitude.
A comparison of figures 4, 5, and 9 suggests that the general
distribution of wells known to penetrate solutional features is
more closely related to the distribution of well data, than to the
geology of the area. Data are very sparse for southeastern Polk,
because few wells have been drilled in this area. As this is an
area of general artesian flow and upward leakage, it may be
assumed that large caverns such as those known and reported in
Hillsborough County may exist in greater numbers than the map
indicates.
In general, there appears to be an increase in depth below
both land surface and msl of the deepest local cavern zones with
increasing distance from the north-central part of the county,
following the slope of the piezometric surface and formational
dip.
The study of the cores from wells 805-154-8 and 801-200-3
produced detailed data on the solution features of the underlying
limestones. The cores show a concentration of solutional fea-
tures in the Avon Park Limestone. A series of cavern develop-
ments and subsequent collapse and filling in the Avon Park Lime-
stone, and a few features in the underlying Lake City Limestone,
occurred prior to dolomitization of these formations. These caverns
show, in many cases, a second stage of solutional excavation
and fill which occurred after dolomitization. In several instances
these solutional features strongly suggest a third stage of solu-
tional excavation, now occurring in the second stage fill. Ab-
stracted logs of these two test holes and of well 815-157-2 pre-
sented earlier indicate the extent of solutional features observed.






REPORT OF INVESTIGATION No. 44


In addition to this series of features, three separate caverns
were penetrated in the Avon Park Limestone in well 801-200-3;
these were in the intervals of 440-445 feet, 5401/-5471/2, and
7291/-7311/ feet, respectively. The upper cavern (440-445 feet)
was underlain by quartz sand and mud fill from 445-455 feet.
The middle cavern was apparently underlain by 1051/2 feet of soft
mud and sand fill, and/or very soft honeycomb limestone, because
casing was set through this interval without drilling.
Limestone-filled solutional cavities were also found in the
upper surface of the Suwannee Limestone in well 801-200-3. After
development of the solutional features, the surface of the Suwan-
nee was replaced by chert. Limestone of Miocene age [Tampa (?)
Formation] which contained numerous Sorites sp. was then de-
posited and filled the preserved solutional features.
No significant solutional features, other than some fine honey-
comb, were observed in the soft, chalky, highly calcareous Suwan-
nee Limestone or Crystal River Formation in wells 801-200-3 and
805-154-8.
SINKHOLES
Undoubtedly the most spectacular surficial evidence of solu-
tional activity is the formation of collapse sinkholes. Thirty
active sinks were recorded in west-central Florida from 1953 to
1960. Nineteen of these have occurred in Polk County, including
those referred to by Stewart (1959, p. 13-16), and all of these
are listed in table 5. Location of these sinkholes are shown in
figure 10.
Because of the relatively small diameter and observable depth,
all of these sinks are believed to have had their origin in the
upper-most limestone of the area concerned. Study of the data in
table 5 and the piezometric, structural, and geologic maps pre-
sented elsewhere in this report indicate a wide variety of local
conditions at the different sites. None of the sinks occurred on
local topographic highs. Land surface at the sites did not exceed
150 feet above sea level. Land surface at 13 sites is 70 feet or
less above limestone; at 5 sites the depth to limestone ranged
from 100 to 225 feet. Only six sites were not closely associated
with, or adjacent to, pre-existing sinkhole areas. Figure 11 shows
two of the sinkholes developed recently in the county.
Between 1953 and 1960, 11 sinks were formed in adjacent
Hillsborough, Pasco, and Hernando counties, and probably others
occurred elsewhere. Though most of these sinks have been of






FLORIDA GEOLOGICAL SURVEY,


Figure 10. Map showing location of recent sinkhole collapses.


small dimensions, their sudden appearance has caused consider-
able local alarm. The formation of sinkholes is a completely natural
occurrence and perhaps most vividly illustrates the principal
geomorphic process operating in this area. Other such collapses
in the future are a certainty.
The multitude of round, closed-in basin lakes in central Flor-
ida and Polk County are widely held to be of sinkhole origin,
and as such are evidence of considerable solutional activity in-the
geologic past. Though many of them may have occurred prior to
the historic past, they are none the less spectacular due to their
size and numbers. The smaller lakes in Lakeland, such as Lakes
Mirror, Wire, and Morton, are almost certainly single sinks. Be-
cause of their very circular shoreline, larger lakes, such as
Hollingsworth in Lakeland, Ariana in Auburndale, and Howard
in the City of Winter Haven, and scores of others in the county,
are also believed to be single sinks. A number of large lakes, with














TABLE 5. Records of the occurrence of recent sinkholes in Polk County
(Reported data shown by "r")

Location Diameter Depth in Altitude in
Number Date of Mode of in feet at feet below feet above Quarter Township Range Nearest
(on fig. 18) collapse occurrence land surface land surface land surface section Section south east town

1 1958-84 (4) Instant 8-12 12-40 r 115-t SE 6 30 25 In Bartow
NE 7
2 4- -4 do 8 r 8 r 130 NW 15 28 24 Lakeland
3 9- -54 do 22 4+ 110- NW 11 28 24 Lakeland
4 5-8-55 do 80 80 138 SW 14 29 24 Highland City
(40 r)
5 4-7-56 do 83 20+ 120 NE 7 30 27 West Lake Wales
(40 r)
6 4- -56 do 40 r 4r 175 : NW 34 30 26 Alturas
7 4-9-56 (2) 3 months 30 1-14 126 NW 28 29 25 Bartow
2 hours 100 i
8 4-10-56 Instant 75 r 10 r 130l SE 34 28 26 Winter Haven
9 7- -57 do 50 16+ 150 NW 22 29 24 Lakeland
10 9-10-57 do 8r 10 r 115 NE 7 30 25 In Bartow
11 11-8-58 do 60 r 40 r 1001: SW 0 30 25 Bartow
12 4-17-59 do 5 9-10 140 SW 30 27 24 Lakeland
13 5-5-69 do 70 r 40 r 130 NE 33 28 26 Winter Haven
14 5-28-60 do 30 unknown 140 SW 17 27 23 Kathleen










68 FLORIDA GEOLOGICAL SURVEY


Li "P
? .C- ,,
:.
-= r I.
~ ~---,---, -. ~..~-c -- r
4r ~fi~i~ j;
? ~L-~14~,-~sr I:1
I ~CT' ~b~c
~ii;~A1U-~..lr~r;;~~'L. L-J~b~Ltri w;Plr9~
".E,. :~i ~C ~~~~ ~.
r
.rbZ '
"~'r .2~-. -. ~-. r. -K..~-~Y~- : ''`'
--- L, c-
,-,~~,
--,-- .- ~c.
~~C~~ -; ;;FJ
~-~c~. ;,,.,
rr 6;4~5P
rCT
--
..i;
~14~
f.~ bE
'3 -1 ~-'E
--
P ;'.' ~1 ~
il4
;"- -- '"
"~ .r
;s~ C +... I ^


Figure 11. Photographs of recent sinkhole collapses.






REPORT OF INVESTIGATION NO. 44


irregular or complex arcuate shorelines, such as Bonny, in Lake-
land; Gibson, near Lakeland; Crooked Lake, at Babson Park;
and many others, are a coalescent group of smaller sinks, or are
more properly referred to as valley sinks. For example, Lake
Bonny in Lakeland, at a stage about 6 feet below normal in June
1956 was shown to be formed by a group of smaller adjacent or
coalescent sinks by aquatic grass and other vegetation growing
around the periphery of the small sinks in the shallow water.
Many sinkhole basins contain only ephemeral lakes or ponds.
Such basins range from several hundred feet in diameter and
scores of feet deep to a few feet in diameter and depth. The
larger, deeper sinks are profuse in the Lake Wales ridge section
where the relatively porous overburden is very thick.
The original depth of the sinks (or depth to point of collapse
or cavern) is generally unknown. Wells on, or near, the floors of
sinkhole basins are few because well drillers have found that
unconsolidated materials in such basins may extend to great
depths. This requires great amounts of well casing, and fre-
quently presents considerable difficulty in drilling, installing the
casing, and developing the well. To further complicate drilling
in such locations, the honeycombed, fractured, or cavernous lime-
stone, is commonly impregnated by sands, silts and muds which
reduce the yield of the wells, and require additional casing in
most instances.

HYDROLOGY
Hydrology is the science that relates to water on and within
the earth and in the earth's atmosphere. Water moves continually
from one to another of these environments, and man diverts a part
of it, temporarily, for his use before releasing it back into the
cycle.
A relatively small part of the rainfall runs off over the land
surface because of the permeable sand cover. A larger part of the
rainfall is returned to the atmosphere by evaporation from the
soil, bodies of surface water, and the vegetation. Part of the rain-
fall infiltrates the surface and percolates downward into the soil,
and much of it is held as a film on soil particles, taken up by
plants, and subsequently transpired back into the atmosphere.
The water in excess of these requirements percolates downward
through the soil and remainder of the zone of aeration, and
eventually reaches the zone of saturation to become ground water.






FLORIDA GEOLOGICAL SURVEY


Within the zone of saturation, water moves through the earth
materials, in response to gravity, to points of discharge such as
springs, lakes, streams, oceans, and wells.
The appraisal of the ground-water resources of the county is
at best only an approximation, because none of the quantities
involved in the various factors can be measured directly runoff
and precipitation. Techniques for accurate measurement of evapo-
ration and transpiration do not exist as yet, and even adequately
detailed measurement of rainfall and runoff are seldom possible
and always costly.
Because of variations in climate, and the requirements of man,
it follows that the quantity of water available in an area will
differ from year to year.

SURFACE WATER
STREAMS
In general, surface drainage in the county is poorly developed
and is almost entirely of two types: (1) basins of interior drainage
(without surface outlet), and (2) streams of very low gradient
which, for the most part, do not occupy well-defined valleys. In
many places these streams have not cut well-defined channels.
The county lies within six major drainage basins, as ordinarily
defined, and these are shown in figure 2.
Approximately 15 percent of the county is drained by the
Withlacoochee River which forms part of the northern boundary
of the county (Heath, 1961, p. 8 and fig. 8). The river flows west
into Pasco County, where it turns sharply north and empties into
the Gulf of Mexico near Inglis in Levy County.
About 4 percent of the west-central part of the county west
of the Lakeland ridge is in the headwaters of the Hillsborough
River and about 8 percent of the southwestern part of the county
(Heath, op. cit.) is in the headwaters of the Alafia River.
The area between the Lakeland and Lake Wales ridges, and
south of Providence, Auburndale, Lake Alfred, and Haines City,
is in the basin of the Peace River. Approximately 35 percent of
Polk County lies in this river basin (Heath, op. cit.).
A narrow finger of the headwaters area of the Oklawaha-
St. Johns River basin extends into northeastern Polk County,
along the west flank of the Lake Wales ridge, north of .Haines
City. This area (2-3 miles wide) represents 3 percent of Polk
County (Heath, 1961, p. 10), and is drained by Green Swamp Run.






REPORT OF INVESTIGATION NO. 44


The eastern 35 percent of the county (Heath, op. cit.) is in
the basin of the Kissimmee River.
Tributaries of all of these rivers are generally short, poorly
defined, and few in number. The course of the Withlacoochee in
this county is a thickly timbered cypress river-swamp that ranges
from about a hundred feet to more than a mile in width. Where
the channel of the river can be defined within the swamp, it is
generally less than a hundred feet wide. The Peace River has a
well-defined channel between Bartow and Ft. Meade.
Table 6 shows the annual runoff in three drainage basins
TABLE 6. Annual runoff by drainage basins, in inches of water over the basin
(Data supplied by Surface Water Branch, U.S. Geological Survey,
Ocala, Florida)

Station 1954 1955 1956 1957 1958 1959
Alafia River at Lithia,
Hillsborough County 14.28 8.40 5.37 18.56 13.26 34.42
Area: 335 sq. mi.
Peace River at Bartow,
Polk County 8.00 3.89 4.47 14.40 10.49 28.16
Area: 390 sq. mi.
Peace River at Zolfo Springs,
Hardee County 12.21 5.63 5.42 14.63 12.10 27.52
Area: 840 sq. mi.
Kissimmee River below Lake
Kissimmee, Polk County 10.93 4.28 2.60 9.30 9.27 20.38
Area: 1,609 sq. mi.


during this investigation. Runoff is given in inches of water over
the basin area. The stations listed here are those nearest to, or
within, the county in the drainage basins. Runoff from the
Withlacoochee and Hillsborough basins cannot be evaluated be-
cause of diversions through the Withlacoochee-Hillsborough over-
flow. The Withlacoochee and Hillsborough basins therefore are
not included in Table 6 or in the sections on recharge. Numerous
other stations exist on tributary streams and canals within the
county. The records of these basins, only a few years of which
are given here, show great differences in runoff from each drain-
age basin from year to year, and between basins during the same
year.
The ridges are drainage divides, however, actual surface runoff
from them is almost nil due to the thickness and permeability of
the surficial sands, and to the numerous closed basins of interior
drainage located on the ridges. For this reason large areas within
a drainage basin actually contribute very little direct surface run-






FLORIDA GEOLOGICAL SURVEY


off to streams. Rainfall in these areas infiltrates to the water table
and percolates through the nonartesian aquifer in response to
downward loss, lateral flow, and storage. A part of this water is
eventually discharged into surface-water bodies, but only a few
such bodies are a part of stream courses.
LAKES
Heath (1961, p. 8) states "Nearly 500 lakes, ranging in size
from less than an acre to more than 35,000 acres (55 square
miles), lie within the county and along its borders." Nine of the
largest lakes are within the broad eastern lowland. They are con-
nected to the drainage systems by means of natural or artificial
channels. It is unlikely that these lakes lose water downward
through the bottoms because they are within areas of significant
artesian flow. Most of the other large lakes in the county are
likewise connected to drainage systems. A majority of the lakes
in the county, however, are closed basins of interior drainage at
the present time.
The entire length of the Lake Wales ridge in this county is
pocked with and flanked by innumerable closed basin lakes. There
are also many sinkhole basins without lakes, and like most of the
lake basins they have no surface outlet. The porosity and perme-
ability of the thick surficial sands of the ridge do not permit
surface runoff, and the thickness and permeability of the mate-
rials filling the bottom of these sinks likewise do not permit pond-
ing of water. The bottoms of these dry sinks are 20 to 50 feet
or more above the water levels in the underlying artesian aquifers,
while water levels of the lake-filled basins are generally 2 to 10
feet above these ground-water levels. It seems likely that in much
of this area, ground water percolating down the slopes of these
dry basins is going into- the artesian limestone aquifers as re-
charge.
These dry sinks range from 100 to 1,000 feet in diameter at
the top of their funnel-shaped basins, but most are 200 to 500
feet in diameter. Topographic depth of the sinks ranges from
25 to 75 feet, the smaller and more shallow basins being found
on lower parts of the ridge flanks or within larger and deeper
basins.
In the Winter Haven and Lakeland ridges, and in the central
and northern inter-ridge areas, dry sinks and basins are few in
number, though lake basins of interior drainage are numerous.
In these areas the surficial sands are not as thick as in the Lake






REPORT OF INVESTIGATION No. 44


Wales ridge. In these two areas the surficial sands are underlain
by greater thicknesses of less permeable materials, and, being
lower topographically, the water table is closer to land surface.
The water levels of the artesian systems are also closer to land
surface except in the highest parts of these ridges. These factors
all operate to increase the percentage of lake-filled basins in these
areas.
The lakes of the county are of significant value to the hy-
drology and economy. They serve to moderate temperatures and
climate, they function as reservoirs for water which might other-
wise leave the area more rapidly as streamflow, and they provide
large supplies of water for irrigation and recreational purposes.
Lakes supply numerous lawn irrigation systems in the cities
and towns along the Lake Wales and Winter Haven ridges. In
Lakeland and the Lakeland ridge section generally, the use of
lakes for lawn and citrus irrigation is relatively much less than
in the other areas.
The City of Lakeland pumps water from Lake Parker and
Lake Mirror for cooling purposes in adjacent power plants. Lakes
Gibson, Crystal, and Bonny have been used for citrus irrigation
in the past, but such usage has been discontinued in recent years
largely because of legal proceedings and injunctions. Scott Lake,
south of Lakeland, is still used extensively for citrus irrigation
whenever irrigation is necessary in the surrounding groves.
Lakes and ponds fluctuate in response to rainfall, ground-
water inflow, evaporation, downward loss to underlying aquifers
by percolation through the lake bottom, to surface inflow and
outflow, and to pumping. The quantities of water involved in these
transfers are dependent on topographic, climatic, and geologic
factors, and the hydrologic setting of the individual lake basin.
The net effect of these factors differs widely from one basin to
another, as shown by the hydrographs in figure 12. Relative im-
portance of the controlling factors is not always evident. As a
result, the prediction of the effect of individual factors on a
given lake is not valid without evaluation of the other factors
involved. Detailed discussion of the basins of Lake Parker and
Scott Lake in the Lakeland area, and the response of these two
lakes to the factors above, are presented in the section of this
report entitled Special Problems.
Lakes Wire and Hollingsworth are in the City of Lakeland and
on the Lakeland ridge. Lakes Deeson, Crystal, and Bonny are on
the lower ground along the east flank of the ridge. Hydrographs

















LAKEiWIRE


. . .


LAKE HOLLINGSWORTH

. . .. . .


13=2
31


'138




.136


- I







:139
1294





'33

13
m



























.131


126

125

iZ4
14


12




6 ;


AAINFALL AT LAKELANO 4






r F









F AMJJA SONOIJMAMJJASONDJFMAMJJASONODIJFUAJJASON5JFMAUJJ ASONCJFMAIJJJASON
;954 1995 1 1957 958 959


Figure 12. Hydrographs of water levels in Lakes Wire, Hollingsworth,

Deeson, Crystal, and Bonny near Lakeland and rainfall at Lakeland, 1954-59.



74






REPORT OF INVESTIGATION NO. 44


for nearby Lakes Parker and Scott are presented in later sections
of this report. Additional data on lake levels, collected as a part
of this investigation, may be found in the basic data report
(Stewart, 1963). Lakes Hunter, Beulah, Morton, Mirror and
Gibson, all in the ridge section near Lakeland, fluctuate closely in
time and amount with Lakes Wire and Hollingsworth.
Water levels in Lakes Deeson, Crystal, and Bonny, near Lake
Parker, declined about 6 feet, and Lake Wire declined 1 foot
between December 1954 and July 1956, whereas the water levels
in Lakes Parker and Hollingsworth and other nearby lakes re-
mained about the same. Hydrographs of the six lakes for 1954
correlate reasonably well.
Lakes Bonny, Crystal, and Deeson have no surface inflow or
outflow. Topographic gradients within the basins are generally
low, and the slope of. the water table is assumed to be low also.
The average flow of ground water into the lakes is probably
equivalent to only a few inches per year over the lake surface, and
this amount was undoubtedly below average during the dry period
from January 1, 1955 through June 30, 1956. Ground-water out-
flow in the nonartesian aquifer is believed to be zero.
One phosphate test hole near the west shore of Crystal Lake
showed predominantly sandy materials extending from the sur-
face down to the limestone bedrock. A good hydraulic connection
such as this may also exist in parts of Lakes Deeson, Crystal,
and Bonny, permitting relatively rapid downward leakage.
During the same dry period (January 1955 to June 1956),
pumping from the artesian aquifers increased as recharge de-
creased, lowering artesian water levels 5 to 10 feet. This in-
creased the hydraulic gradient between the lake levels and the
artesian aquifers and probably increased the rate of leakage from
the lakes.
The combination of decreases in rainfall and ground-water
inflow plus increase in evaporation and vertical leakage appear
to have been sufficient to account. for the decline in lake levels.
With the return of near- or above-normal rainfall late in
1956, lake levels began to rise. In November and December 1956,
the outlet of Lake Parker was raised 1 foot by the City Engineer
of Lakeland. The surplus water created was then pumped into
Lake Bonny. The pumped water, plus the rainfall, accounts for
the sharp rise in the level of Lake Bonny in November 1956,
which amounted to approximately 2 feet. Continued above-normal
rainfall in most of 1957 returned the lakes to, or above, their






FLORIDA GEOLOGICAL SURVEY


1954 levels. Lake Deeson was the only exception to this in the
Lakeland area.
The cause of this lack of recovery by Lake Deeson is uncertain
and data are few. A major factor may be very localized below-
normal rainfall. Similar instances are indicated on the hydro-
graphs of Lake Bonny in September-October 1955, and at other
times. This is possible because of the predominantly thunder-
storm-type of rainfall in the entire area. Lake Deeson's failure
to recover in 1957 and in 1959, as well, may also be due in part
to increased local pumpage and downward leakage from the basin.
The lakes all declined in 1958 because of below-normal rainfall.
In 1959, record high rainfall was established at the Weather
Bureau office at Lakeland when a total of 70.24 inches was re-
corded. All the lakes, except Parker and Deeson, exceeded their
1954 levels by significant amounts. In September 1959, it was
necessary for the city and county to reverse the procedure of
1956, and excess water from Lake Bonny which threatened shore-
line property was drained into Lake Parker.
Stage measurements of Lake Ariana in Auburndale, and Lake
Hancock near Highland City, in 1958 and 1959 (Stewart, 1963,
p. 106) show that these lakes also fluctuate closely with those in
the Lakeland area. The range of fluctuations of these lakes ap-,
pears to be about equal to those of Lake Wire for the 2-year
period.

EVAPOTRANSPIRATION
The term evapotranspirationn" has been used to denote the
return of water from the earth to the atmosphere by direct
evaporation and by the life processes of plants. It includes evapo-
ration from water surfaces as well as soils and vegetation, and
the transpiration by vegetation.
The source of data on evaporation from free-water surfaces
nearest the area described in this report is a standard U.S.
Weather Bureau evaporation pan at the Orlando Water Plant in
Orange County. Evaporation and other climatic factors at Or-
lando differ somewhat from those at Lakeland, but in the absence
of local data, the data from the Orlando station are used in this
report. A pan coefficient of 0.7 is applied to correct the annual
rate of evaporation from the pan to that from a lake (Follans-
bee, 1934, p. 705). The average, corrected, annual evaporation
at the Orlando Water Plant, for the period January 1954 through






REPORT OF INVESTIGATION NO. 44


December 1958, is 40.6 inches. This compares favorably with the
(ata obtained from the now-abandoned Lake Hiawassee station
of the U.S. Weather Bureau, near Orlando, from 1940-1946. This
average also seems appropriate in view of available rainfall and
runoff data.
Meyer (1942), on the basis of computed evaporation, produced
a series of evaporation maps which showed the Polk County area
to have an annual average evaporation of 50 inches (op. cit.,
map no. 4). Meyer's map No. 10 shows this area to have equal
mean annual evaporation and precipitation. Since considerable
runoff does occur in this area (table 5), the evaporation rate
proposed by Meyer is inappropriate.
Transpiration is the release of water from plants during their
life processes. No accurate method has been developed for meas-
uring the rate of transpiration of various types of vegetation in
a humid subtropical climate such as that of Polk County, but
transpiration is undoubtedly a significant factor in the water
budget of this area. Studies by Koo (1953) indicate that transpir-
ation of citrus trees is very high. His study utilized test plots
of 15-year old Marsh grapefruit trees, and results indicate that
average daily consumption of water from the nonartesian aquifer
is about 34.2 gpd/tree (gallons per day). The daily consumption
varied greatly during the year. Based on this average, and 65
to 70 trees per acre, annual transpiration losses would be about
30 inches per year. If allowances are made for direct re-
evaporation from the foliage and land surface, and transpiration
by cover crops and weeds, it is seen that evapotranspiration rates
in citrus groves approach open-water evaporation rates in the
area. This is also indicated by the work of Penman (1956), who
states that transpiration in humid climates near the equator ap-
proaches a factor of 0.7 of open-water evaporation. The general
close relationship of evaporation and transpiration is also stated
by Blaney (1956). For purposes of this report the evapotranspira-
tion rate of 40 inches per year is believed to be reasonable.

GROUND WATER
OCCURRENCE
Ground water is the subsurface water in that part of the zone
of saturation in which all pore spaces are filled with water under
hydrostatic pressure. It is derived from that fraction of rainfall
which has percolated downward, through the soil and zone of






FLORIDA GEOLOGICAL SURVEY


aeration, and reached the zone of saturation. The ground water
then moves laterally, under the influence of gravity, toward places
of discharge such as wells, springs, streams, lakes, or the ocear.
Where hydrologic conditions permit, some of the water may move
downward into other underlying aquifers.
An aquifer is a formation, group of formations, or part of a
formation, in the zone of saturation, that is permeable enough to
transmit usable quantities of water. Ground water may occur
under either nonartesian or artesian conditions. Where the upper
surface of the zone of saturation, called the water table, is free
to rise and fall it is said to be nonartesian. Where the water is
confined in a permeable bed between less permeable beds, so that
its surface is not free to rise and fall, it is said to be artesian.
The term artesian is applied to ground water that is confined
under sufficient pressure to rise in wells above the top of the
permeable bed that contains it, though not necessarily above the
land surface. These less permeable beds are called confining beds.
The height to which water will rise in a tightly cased artesian
well is called the artesian pressure head. The imaginary surface
coinciding with the water levels of artesian wells is called the
piezometric surface. This surface is generally represented on a
map by contour lines that connect points of equal altitude of the
pressure surface. Water in an artesian aquifer moves from areas
of high artesian pressure toward areas of lower artesian pressure,
at right angles to the contour lines representing the piezometric
surface. Where the contour lines enclose an area of high water
levels (high artesian pressure), the flow is away from the area on
all sides. The artesian aquifer is being replenished in such an area.
Conversely, where the contour lines enclose an area of low water
levels, water is flowing into the area from all sides and is being
discharged from the aquifer. Areas in which aquifers are re-
plenished are called recharge areas; areas in which water is lost
from aquifers are called discharge areas.
NONARTESIAN AQUIFER
CHARACTERISTICS
In Polk County ground-water supplies are obtained from four
different aquifers, which were first recognized by Matson (Matson
and Sanford, 1913, p. 389). The uppermost of the four aquifers is
in the unconsolidated sand and clayey sand at, and just below,
land surface. These sands cover the entire county and, together
with the underlying coarse plastics where present, form the ion-






REPORT OF INVESTIGATION No. 44 79

a:tesian aquifer. The aquifer is used for domestic supplies and
for irrigation purposes requiring relatively small amounts of wa-
er. Tubular wells in this aquifer range from 11 to 4 inches in
diameter and from 7 to 35 feet in depth; there are also a few dug
ells and pits in use. Hand (pitcher) Pumps are commonly used
for domestic purposes, and gasoline-driven suction pumps are
used for irrigation. The irrigation wells usually do not produce
more than 20 to 30 gpm (gallons per minute), though several are
known to produce 100 gpm or more.
Wells are commonly constructed by driving small-diameter
pipe into this aquifer. The sand is then cleaned from the pipe, and
the well is deepened by water-jetting. There are very few dug,
sand-point, screened, or gravel-packed wells in the county. Wells
in the aquifer, as locally constructed, rarely retain their original
depth because the loose sand will not stand in the walls of an
open hole.
The thickness of the aquifer differs widely over the county,
and generally ranges from a few inches to 250 feet. However, ex-
treme thicknesses of 300-600 feet or more are reported along the
eastern side and on the crest of the Lake Wales ridge (fig. 4,
wells 755-134-1, 801-136-2, 818-140-1, 820-140-1). Clay content,
and hence porosity and permeability, likewise differ widely over
the county.
Figures 13 and 14 show the water levels in, and the locations
of, some of the nonartesian wells in the county. Though a great
number exist, there were not enough to provide the amount of
control necessary for a reasonably accurate map of the water
table of the entire county.
WATER-LEVEL FLUCTUATIONS
During the course of this investigation, water levels were
measured periodically in several wells in the nonartesian aquifer,
and continuous recorders were installed on others. Hydrographs
of representative wells in this aquifer are shown in figure 15.
The well illustrated in figure 15 is a part of the permanent net-
work of observation wells maintained in the state, and records of
the water levels have been previously published in Water-Supply
Papers of the U.S. Geological Survey under the well number Polk
47. Additional water-level data from wells in this aquifer in Polk
County have been previously published (Stewart, 1963, table 4).
Water-level fluctuations in this aquifer are due to (1) recharge
by rainfall, and (2) discharge by natural gravity flow down gra-
















































Figure 18. Water-table contour of the Lake Parker area, June 25-80, 1956.


__ __






REPORT OF INVESTIGATION NO. 44


igu e 14 _.__. _sh_.in .. si w_. .. .. t. h
\ POLK C\UNIY
-- -.- ---- ..... --__ -0 Ni. UN
20 Su~ 20 TO TO^1 0 1 2 3 4 5r *
Figure 14. Map showing water levels in selected wells penetrating the
nonartesian aquifer (October 29, 1959 to February 4, 1960).
dient to lakes and streams, evapotranspiration, downward loss
into underlying aquifers, and pumping from wells. None of the
wells illustrated here are affected significantly by pumping.
Water-level decline due to downward loss or to natural lateral
gravity flow cannot be readily distinguished on the hydrographs.
Generally water levels in wells on topographic high areas or
slopes will decline at greater rates from these causes than will
wells located low on topographic slopes or relatively flat locations.
Recharge is reflected by rising water levels, and the rate and
amount of rise is determined by the amount of rainfall, the
porosity and permeability of the aquifer, and other factors.
The range of fluctuation in nonartesian wells differs widely
over the county. The records of six wells, including those shown
:n figures 15 and 30-32, show net changes of 5.5 to 12.7 feet from
highest to lowest levels of record in individual wells. The greatest
iotal annual fluctuation ranged from 4.3 to 9.6 feet in individual
wells.






FLORIDA GEOLOGICAL SURVEY


114

S113







10







107
o -l- |

















IO6 -Well 81-136-2, near Haines City
(Nonortesion aquifer)
105
1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
Figure 15. Hydrograph showing fluctuations of the water table in a well
c108 -- -

* 10 7 --- --- -- --- --- -- --- --- -V --- --- --


o 106 -- Well 810-136-2, near Haines City
(Nonartesion aquifer)

1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
Figure 15. Hydrograph showing fluctuations of the water table in a well
near Haines City (810-136-2) in the nonartesian aquifer.


UPPERMOST ARTESIAN AQUIFER
The pebble phosphate deposits that immediately underlie the
surficial sands of the Lakeland-Auburndale area form an artesian
aquifer of undetermined thickness and areal extent which is re-
ferred to as the "uppermost artesian aquifer" in this report. The
aquifer is in the coarse, sandy, phosphatic gravel zones (matrix)
of the phosphate deposits, and is confined above by the heavy
dense clays of the Bone Valley Formation, and below by clays
which may be either of the Bone Valley or Hawthorn Formations.
The few wells penetrating this aquifer are located on the lowland
between Lakeland and Auburndale, and are similar in construc-
tion to wells in the nonartesian aquifer. Near Saddle Creek the
piezometric surface of this aquifer is near the level of the water
table (figs. 13 and 14). Generally, however, it is 3 to 6 feet below
the water table.






REPORT OF INVESTIGATION NO. 44


In the southern part of the pebble phosphate fields (Bartow-
Homeland-Ft. Meade, fig. 4) the aquifer may be more productive
because it is generally thicker and coarser. In that area, the
piezometric surface may be intimately related to the nonartesian
aquifer because the upper confining bed is more porous than in
the Saddle Creek area. Well data from the southern part of the
mining area are very few. Though well data are lacking, similar
artesian conditions may exist elsewhere in the county in the sands
and clays generally overlying the limestone surface. Such occur-
rences may be of local nature and unrelated to the geologic units
present in the Saddle Creek-Peace River mining area.
Water-level observations made during the drilling of deep wells
in the Lakeland area indicate that the piezometric surface of this
aquifer is higher than that of the aquifers below it.


SECONDARY ARTESIAN AQUIFER
CHARACTERISTICS
The secondary artesian aquifer which is formed in the lime-
stone members of the Hawthorn Formation is used much more
than either of the two aquifers previously described. It is con-
fined above by the clays in the upper part of the Hawthorn. For-
mation or the lower part of the Bone Valley Formation, and is
confined below by the blue clay of the Tampa Formation.
The aquifer is present over much of the county south of Polk
City. Along much of the northern boundary the limestones are
10 feet or less in thickness, and are soft and deeply weathered.
Permeabilities in such locations (wells 805-153-2, 805-156-1,
806-156-1) are very low. Isolated areas in which these limestones
have been removed by erosion exist miles south of the general
boundary indicated.
An aquifer within the Hawthorn Formation is also reported in
recent investigations of other parts of central Florida. Bermes
(1958, p. 19-20) refers to this aquifer as the "Shallow artesian
aquifer" in Indian River County; Peek and Anders (1955, p. 20),
and Peek (1958, p. 26), report a separate artesian aquifer in these
limestone units in Manatee County; Klein (1954, p. 22) likewise
reports a separate artesian aquifer in the limestones of the Haw-
thorn Formation in the Naples area of Collier County. All of
these authors find that the pressure head in these aquifers is 5 to
20 feet below that of the underlying Floridan aquifer, in the areas






FLORIDA GEOLOGICAL SURVEY


concerned. Peek and Anders (op. cit.) note that the difference in
head appears to decrease eastward in Manatee County.
In Polk County many wells draw water from this aquifer in
the lowland of Saddle Creek and the Peace River, and these are
used for domestic supplies and truck-farm irrigation Others,
used almost exclusively for domestic supplies, are scattered over
the southern two-thirds of the county. Locally, a few large di-
ameter citrus irrigation wells produce large quantities of water
from this aquifer. Such production is possible because these wells
penetrate large solutional caverns in the limestones. Generally
wells in this aquifer range from 11/4 to 6 inches in diameter and
from 30 to 75 feet in depth. Wells that utilize this aquifer in the
southern part of the county and in the ridge sections are con-
siderably deeper because of the dip of the formations and the
altitude of land surface. The casing of wells drilled into this
aquifer usually terminates in the uppermost part of the limestone,
but in some wells it is driven only into the clays of the overlying
formations. This latter practice may lead to eventual collapse of
the clays and clogging of the wells.
In lowland areas, water levels in wells open only to this aquifer
are generally 5 to 10 feet below the water table and are also below
water levels in the uppermost artesian aquifer where it is present.,
In the ridge areas the water level may be more than 100 feet
below the water table because of the higher altitude of land sur-
face. Figure 16 shows hydrographs of wells which are open only
to the secondary artesian aquifer. Well 744-131-1 is one of the
permanent network of observation wells in use by the U.S. Geo-
logical Survey, and annual water-level data have been previously
published in Water-Supply Papers of the Survey under the well
number Polk 51. Additional water-level data has been published
by Stewart (1963, table 6). The hydrographs from widely sepa-
rated wells in this aquifer correlate closely, and the very local
effect of pumping causes only slight variations in the general pat-
tern of the water-level fluctuations.
Locally the secondary artesian and the Floridan aquifers are
in direct contact or relatively better hydraulic connection through
faulting, jointing, buried sinks, areas of artesian flow, or areas
in which the clay of the Tampa Formation is absent. The water
level of the secondary artesian aquifer will equal or closely ap-
proach that of the Floridan aquifer in these areas. However, a
short distance from such areas the secondary aquifer resumes its
separate identity.






REPORT OF INVESTIGATION NO. 44


0>
96

1954 1955 1956 1957 1958 1959

E
94



E 90

88
ss In II

86 -


84
82-
0
82 -- -- -I- -- -



Well 744-131-1, near Frostproof
(Secondary artesian aquifer)
1949 1950 1951 [1952 1953 1954 1955 1956| 1957 1958 1959

Figure 16. Hydrographs showing fluctuations of the piezometric surface
in a well near Lakeland (803-153-18) and a well near Frostproof (744-131-1)
in the secondary artesian aquifer.


THE PIEZOMETRIC SURFACE
Figure 17 is a map of the piezometric surface of the secondary
artesian aquifer in the lowland along Saddle Creek in June 1956.
The large cones of depression around the springs at points E, F,
and G were caused by discharge from the aquifer in mine pits
operating at the time of mapping. The map was made near the
end of a period of extended drought (1954 through 1956).
Much of the area between Saddle Creek and the western
branch of Saddle Creek, south of the springs at point E, is a
mined-out area, used as a water-storage area in June 1956. Lime-






FLORIDA GEOLOGICAL SURVEY


Figure 17. Piezometric-contour map of the secondary artesian aquifer of
Lake Parker area (June 1956).


stone of the Hawthorn Formation was exposed at many places
in the floors of these pits during mining operations. Artesian
springs which issued from the limestone during mining operations
have been impounded. Water was pumped from the operating pits
and was either used in mining operations or stored in the aban-
doned pits. Mining in the Saddle Creek mine (south of point E)
ceased January 10, 1957. Mining in the vicinity of the more
northerly springs ceased some months later. By February 1960,
mining had shifted generally to the north and east of the spring
sites shown and was in progress north of 804-151-7. Mining in the
Orange Park mine, east and northeast of 807-154-2, began May
5, 1957, and was still in progress in February 1960.
The effect of mining, and the cessation of mining, on a well
(803-153-18) in this aquifer is shown by the hydrograph in figure
16. The areal effect of the cessation of mining in the Saddle Creek
area, and the generally concurrent return of normal rainfall, is
shown by figure 18. Water levels on the ridge areas rose 3- to 5
feet over those of June 1956, while in the lowlands along Saddle


a- rrw ;j, G


.. .-;,I, K S.-. J





REPORT. OF INVESTIGATION No. 44 87





... ....-

















Figure 18. Piezometric-contour map of the secondary artesian aquifer in
Lake Parker area (October 1959 to February 1960).


Creek water levels rose as much as 15 feet, and 10-foot increases
were common.
Well 744-131-1 (fig. 16) located in Frostproof is a nonmining
area far beyond the effects of mine pumping. The net effect of

in well 744-131-1, and 13 feet in 803-153-18.
.14


5-r ---- ----













In preparing figure 18 a number of revisions of an earlier map
_ )loms i) U : G*Wz9-1 S-7 _y-119y byKGS Sle J






Figu(Stewart, 1956. Piezometric-contour map because the secondary artesian aquifer in
tesian aquifer area (October 1959actually cover the entire area of the map,1960).

Creek water levels roll thought. These as muchanges 15 feet, and 10-foot increases
were common.




ell 744-131-1 (fig8. Because of intense erosion an16) located possible extensive mis a nonminingr fault-
ing,area far beyond the limestoneffects of the Tampa Formation is locally tinghe net effect of





most limestone. The Hawthorn is very thin in a few wells pre-
generviously thought to be rainfall may in Hawthorn, and which are now
tiveknown to be multi-aquiferrise of water levels of the wells, open to both the secondary andet
underin well 744-131-1,ridan artesian aquifers.803-153-18.
In preparing figure 19 is a map showing altitudevisions of water levels in the
aquifeart, 1956,ing the 1) inter necessary because t95960, he such data is
tesian aquifer did -not actually cover the entire area of the map,
as originally thou ght. These changes are made in figures 17 and
18. Because of intense erosion and possible extensive minor fault-
ing, the limestone of the Tampa Formation is locally the upper-
most limestone. The Hawthorn is very thin in a few wells pre-
viously thought to be entirely in Hawthorn, and which are now
known to be multi-aquifer wells, open to both the secondary and
underlying Floridan artesian aquifers.
Figure 19 is a map showing altituIdes of water levels in the
aquifer during the winter months- of 1959-60, where such data is






FLORIDA GEOLOGICAL SURVEY


Figure 19. Piezometric-contour map of the secondary artesian aquifer
(October 1959 to February 1960).

available in the county. The map also shows the approximate
northern extent of the aquifer. Water levels declined from 0.5 to
3.4 feet in eight observation wells during the period. The map
shows that an extensive trough exists in the piezometric surface
along the Saddle Creek-Peace River valleys, and that it passes
between several significant piezometric highs, which indicate re-
charge areas. A very extensive piezometric high underlies the
west flank of the Lakeland ridge, and occupies much of the south-
western part of the county. Another high underlies a broad flat
area south of Lake Buffum. A smaller high area is located on the
ridge north of Lake Ariana.

AREAS OF ARTESIAN FLOW
Flowing artesian wells in this aquifer existed as late as 1948
in the general vicinity of well 803-152-2, about a half a mile
northeast of the U.S. Highway 92 bridge over Saddle Creek. Water






REPORT OF INVESTIGATION NO. 44 89

levels in that area were reported to have been about 2 feet
above land surface in 1948, but they had dropped to about 11 feet
below the surface by 1956. In 1959 they closely approached land
surface for brief periods, and generally were about 2 feet below
land surface. The area of artesian flow apparently extended about
three-fourths of a mile on either side of Saddle Creek; its north-
south extent is unknown. The area of flow was described by
Sellards and Gunter (1913, p. 263), and Matson and .Sanford
(1913, table facing p. 390) reported a flowing well in this area.
It is likely that flowing wells could be obtained along the valley
of the Peace River from the southern county line north midway
to Lake Hancock. Observations of ground-water leakage in the
secondary aquifer in the vicinity of well 745-147-1 (fig. 19), in
August 1958, showed that water levels rise rapidly toward high
ground up the valley wall, and the area of artesian flow may be
less than 100 feet wide in some places. Progressively lower flow
and head may be expected upstream; and in the vicinity of Lake
Hancock, wells probably would only flow during brief periods of
very high ground-water levels.

WATER-LEVEL FLUCTUATIONS
The range of water-level fluctuations in wells in the aquifer
differs widely over the county. The causes of the greatest fluctua-
tions are due to recharge and to pumping from the aquifer. The
hydrographs of wells show net changes from highest to lowest
water levels of record of 9.4 to 24.5 feet in individual wells. The
maximum annual fluctuation in these wells ranged from 7.3 to
17.9 feet.

FLORIDAN AQUIFER
CHARACTERISTICS
The principal aquifer in the area of this investigation is the
Floridan aquifer, which consists of a series of limestones that
range from middle Eocene to Miocene in age. It is an artesian
aquifer and is the source of all major public, industrial, and ir-
rigation water supplies in the county. The name Floridan aquifer
was introduced by Parker (Parker and others, 1955, p. 189) to
include "parts or all of the middle Eocene (Avon Park and Lake
City limestones), upper Eocene (Ocala limestone), Oligocene
(Suwannee limestone), and Miocene (Tampa limestone and per-






FLORIDA GEOLOGICAL SURVEY


meable parts of the Hawthorn formation that are in hydrologic
contact with the rest of the aquifer." According to Cooper,
Kenner, and Brown (1953, p. 17), this aquifer "underlies almost
all of Florida, the coastal area of Georgia, and the southeastern-
most parts of South Carolina and Alabama."
In Polk County the youngest (uppermost) member of the
Floridan aquifer in a few areas is the limestone units of the
Tampa Formation. In the northern and eastern parts of the
county, the uppermost limestone member of the Floridan aquifer
is the Ocala Group, most commonly the Crystal River Formation
(fig. 5). In the remainder of the county the Suwannee Limestone
is the upper member of the aquifer, although local thin limestones
of the Tampa may be found. Wells penetrating the Floridan
aquifer range from 2 to 30 inches in diameter and from 60 to
1,400 feet in depth.
Wells that are open to both the secondary artesian aquifer
and the Floridan aquifer are multi-aquifer wells. They range from
3 to 12 inches in diameter, and from 70 to 850 feet in depth. Most
of them are small diameter and are used for domestic and small
irrigation requirements. Water levels in multi-aquifer wells are
about the same altitude as those in wells open only to the Floridan
aquifer. This is due to the higher permeability of the Floridan,
aquifer.
Unklesbay (1944, p. 13-14) reports that in Orange County the
formations constituting the Florida aquifer act hydrologically as
a unit, and that water levels in the upper part of the aquifer are
the same as those in the lower part. Bermes (1958, p. 21) reports
that the aquifer also functions as a hydrologic unit in Indian
River County, on the Atlantic coast. Stewart (1959, p. 33) re-
ported similar conditions in northwestern Polk County.
Peek and Anders (1955, p. 15), and Peek (1958, p. 26), report
the existence of low permeability zones in the aquifer which re-
tard vertical movement of water. Wyrick (1960, p. 27-28) shows
extensive stratigraphic barriers within the aquifer in Volusia
County. Bishop suggests that significant stratigraphic barriers
also exist in the aquifer in Highlands County.
Table 7 is a compilation of water-level measurements made in
Polk County. These data do not show significant changes in static
water levels with increased depth of drilling in the Floridan
aquifer. This indicates that the various formations comprising
the aquifer have a free hydraulic connection, and that they func-
tion as a single aquifer. The changes actually observed and re-






REPORT OF INVESTIGATION NO. 44


corded are caused by (1) measurements being made immediately
after drilling or bailing and before the water has recovered to a
static level; (2) penetration of significant solutional features;
(3) measurements made when open-hole portion of the well is
only a few feet (805-155-2); or (4) well terminates in a local zone
of very low permeability (as in the 210-219 foot interval of
803-156-11 and in the Lake City and Oldsmar zones of 801-200-3).
The bottom of the Floridan aquifer, and hence its thickness,
has not been previously determined. At the present time only a
few wells penetrate the Lake City Limestone and deeper forma-
tions in this county. However, the existence of highly soluble gyp-
sum and unaltered anhydrite, in the Oldsmar, Lake City and
lower part of the Avon Park Limestones, discussed earlier in this
report, show conclusively that there has been no appreciable
ground-water circulation in these units since their deposition.
Vernon (1951, p. 87, 90-91) indicates that these minerals are
common in the Lake City and Oldsmar, and (op. cit., p. 82-85) in
the underlying Cedar Keys Limestone (Paleocene) and upper part
of the Lawson Limestone (Upper Cretaceous). Hence, the bottom
of the Floridan aquifer in the Lakeland area, and probably most
of Polk County, coincides with the base of the Avon Park Lime-
stone. It appears that this may also be true in many other parts
of peninsular Florida.

THE PIEZOMETRIC SURFACE

Figure 20 is a contour map of the piezometric surface of the
Floridan aquifer during the period October 1959-February 1960.
During the period of measurement water levels in the aquifer
were recorded continuously in seven wells, and measured periodi-
cally in 17 others. The net changes observed during the measure-
ments are indicated on the inset map on figure 20.
With the exception of about 10 city wells, all of the pumping
wells shown on the map are industrial or citrus irrigation wells
being pumped for long periods of time. They are therefore capable
of exerting great influence on the water level of surrounding
areas. The areas of drawdown shown around the pumping wells
are approximate in most instances, and are intended to illustrate
areas of generally heavy pumpage.
The piezometric surface of the Floridan aquifer in Polk
County is a very irregular dome-shaped surface, and is highest in
the north-central part of the county (fig. 20). The dome is elon-









TABLE 7, Water levels observed during drilling operations
(Aquifer: 1, nonartealan; 2, secondary artesian; 3, Floridan; 4, uppermost artesian)

UBOB Date of Depth to water
well measure- Depth of casing Depth of well below lend Geologic
number meant (feet) (feet) surface (feet) Aquifer formation Remarks

730-120-1 U- 7-50 320 1,076 22,0 3 Lake City FOB well number W.2842, measured by E. W


0-15-50
0-21-50
0-28-50
10- 6-50
757-166-2 12-20-54
12-30-54
800-159-1 0-28-54
0-30-64
7-18-64
7-22-64
801-200-3 12-14-59
12-17-59
12-23-59
12-30:59
1- 2-60
1- 6-60
1-20-60
1-25-60
1-30-60
2- 4-60
2- 8-60
2-15-60
2-15-60
2-15-60


820
320
820
820
04
04
71
02
126
148
82
520
701
750
778
778
1,0706
1,0706
1,0761
1,0706
1,070
062
690
32
60
66
30
s8
386
36
80
386
48
309
309
*848


1,106
1,130
1,180
1,210
270
281
74
00
178
265
186
64714
711
754
783
887
1,185
1,368
1,648
1,808
1,842
1,842
1,842
1,842
69
130
165
167
167
176
193
193
276
310
323
865


Bishop Ueologlet,Florida Geologioal Survey
(Bishop, 1060 p. 108)


FOS well number W-3420


Also, open to clay unit, Tampa formation
Cavities from 440 to 445 feet and 640ji to
647H4 feet
Cavity from 729 0 to 781)1 feet


23.0
23.0
22.7
21.0
113.0
143 7
6 20
7.50
64.42
64.42
6.76
42.00
40.84
39,38
39.67
40.60
43.7
48.9
63.6
62,0
42.9
40.0
40.8
30.7
20.46
28.0
11.10
10.89
10.03
10.84
10.94
10.71
19.39
61?
24.59
24.18


2 Hawthorn
3 Suwannee
4 Bone Valley
2 Hawthorn
8 Suwannee
3 Crystal River
2 Hawtliorn
8 Avon Park
3 do
3 do
3 do
3 do
3 Lake City
3 do
3 Oldsmar
3 do
3 do
3 do
3 do
3 do
2 Hawthorn
3 Suwannee
3 suwannee
3 do
3 do
3 do
3 do
3 Crystal River?
2.3 Crystal River
3 do
3 do
3 do


After well at rest overnight




. Before bailing


After 2 days rest


802-168-4

808-151-0



803-153-30


12-31-64
1- 1-64
10-20-54
10-26-64
10-27-64
10-27-64
10-27-54
10-29-64
11417-64
11-18-54.
11-19-54
11-23854






11-28-54
11-23-54
12-28-54
12-29-54
12-29-54
808-156-11 10-11-55
10-11-55
10-11-55
10-12-55
10-12-55
10-12-55
10-13-55
10-13-55
10-14-55
10-17-55
10-17-55
10-24-55
10-25-55
10-26-55
10-26-55
10-31-55
803-157-2 1-18-55
1-18-55
805-155-2 11-28-55
11-28-55
12- 2-55
12- 6-55
12- 5-55
12- 5-55
12- 5-55
12- 5-55
12- 5-55
12- 0-55
12- 6-55
12- 6-55
1-' 5-56
1- 5-56
1-' 5-56
1- 6-56
1- 6-56
1- 6-56
1- 6-56
2-10-56
2-27-56
2-27-56


348
348
371
42
21
68
86
87
87
87
87
87
87
87
87
87
87
87
87
87
87
87
228
261
9
29
58
60
60
60
60
00
60
60
60
60
60
252
252
258
2538f
255
255
60
82 fJ
82


369
378
872
872
372
84
86
100
150
170
206
207
210$)
211
219
219
219
219
219
2600
273
820
328
275
347
10
34
58
71
89
104
124
160
180
200
225
252$
252)
257$
268
278
311
311
311
311
255
255


23.00
23.15
80.9
20.55
22.31
14.35
35.35
36.75
37.15
39.30
35.18
89.08
38.70
38.63
39.11
36.07
35.70
38.79
89.01
40.40
40.07
38.50
110.20
110.0
6.0
3.86
9.73
11.40
26.5?
18.5?
19.5?
17.6?
19.3
17.75
18.08
18.01
18.59
34.80
33.96
20.25
22.42
32.8
22.20
19.16
24.85
24.36


Williston?
Williston
do
do
do
Hawthorn
do
Tampa
Suwannee
do
do
do
do
do
do
do
do
do
do
do
Crystal River
do
do
Suwannee?
Crystal River
Surface sand
do
Hawthorn
do
Suwannee
do
Suwannoe
do
Crystal River
do
do
do
do
do
do
do
do
do
do
do
do
do


After bailing
Do
Water level reported by driller


FGS well number W-3773
Interbedded blue clay and limestone
Before bailing, after drilling
Do
After one bailing
Idle one-half hour prior to moaetrement
Eighteen minutes after stopped
Before work started
Fifteen minutes after bailing
After drilling and before bailing
Thirty-five minutes after bailing
Just prior to dynamiting with 4 sticks
Eighteen minutes after dynamiting well
After drilling, before bailing
Do
After 2$ days idle



FOS well number W-3766
Well idle 24 hours
(Also open to Tampa blue clay); well idle 2f
days
By popping
Do
By popping
Do
Do
Well idle 16 hours
Work terminated
Work resumed-measurement before work
started

Well idle 15 hours
Well idle 30 minutes
After heavy bailing
Work terminated; well idle 30 minutes
Lower part of well collapsed or bridged
Well idle 35 minutes










TABLE 7 (Continued)


USG8 Date of
well measure-
number ment

805.150-2 12-27-55
12-27.55
12-27-55
800.155- 12-14.54
12-14-54
12-14-54
12-14-54
12-14-54
807-154-3 1-23-50
1-23-50
1-23-50
1-24-50
1-24-40
1-24-50
1-25-58
1-26-50
1-25-50
1-26-50
1-26-50
1-26-50
1-20-66
1-30-60
1-80-50
809-147-1 2-18-50
2-20-50
2-21-56
2-21-50
2-22-56
809-148-2 6- 3-57
6- 7-50
6- 8-50
6- 8-59
6- 9-59


-"


Depth of casing
(feet)

20
20
40t
20
00
60
84
84
53
53
53
53
53
53
53
53
53
53
53
53
53
68
53
53
113
113
113
113
113
47

101
101
101


Depth of well
(feet)

28
41i
82
35
72
83
104
120
00
72
02
117
180
180
188
210
276
317
345
352
360
300
411
100
350
405
490
523
83
05
109
124
200


Depth to water
below land
surface (feet)

0.82
7,23
10,15
7
10.85
12.10
11.4
10.7
7.55
15.52
11.97
12.10
13.60
13.45
13.25
13.52
13.60
13.30
13.00
13.47
13.42
13.15
13.32
8.23
8.00
8.19
8.40
7.80
40.0
51,04
89.1
61.00
52.35


Aqruifur

4
2
3
1
2
2
2
2
2
2,3
2,3
2.3
2,3
2,3
2,3
2,3
2,3

2,3
2.3
2.3
2,3
2,3

3
3
3
3
3
4
4


3


Geologio
formation

lone Valley
Hawthorn
Tampa?
Sand
Calcareous
sandstone
Hawthorn
do
do
Hawthorn
Tampa
Suwannee
do
do
Crystal River
do
do
Williston
Inglls
do
do
Avon Park
do
do
Crystal River
Avon Park
do
do
do
Bone Valley?
Hawthorn clay
Tampa clay
do
Inglis


Remarks

FOS well number W-3760
After 15 minutes rest; cavity from 77 to 81 feet
FOS well number W-3423


Well Idle 10 minutes

Well Idle 10+ hours; FGS well number
W-3820
Well idle 2 ; hours
Well idle 10 hours
Well idle 17 minutes; top of Crystal River
Well idle 1 hour
Well idle 17 hours
After bailing
Well idle 17 minutes
Well idle 16 hours
After balling
Well idle 23 minutes
Well idle 31 days
Well idle 7 minutes
Measurement by E. W. Bishop, Florida Geo-
logical Survey; FOS well number W-4275


Cavern from 403 to 511 feet
All measurements by F. W. Meyer; U.S.G.S.;
FGS well number W-5045

Top Floridan aquifer and Crystal River
formation from 15 to 126 feet





0-10-50 101 400 51.40 3 Avon Park
6-15-59 120 51036 51.25 3 do


810-144-1 7- 7-50

7- 7-59
7- 7-59
7- 7-59
7- 7-59
7- 7-59
7- 7-69
7- 7-69
7- 7-69
7- 8-69
7- 8-59
7- 8-59
7- 8-59
7- 8-69
7- 8-69
7- 8-59
7- 8-59
7- 8-59
7- 8-59
813-149-1 1-31-69

1-31-59
2-.2-59
2- 2-59
2- 2-59
2- 8-69
2- 8-59
2- 3-59
7- 9469
7- 9-59
7-10-59
7-10-59
7-10-59
9- 2-59
9- 2-59
9- 2-59
d81-201-1 7-81-59

7-31-59


7.00


83
88
88
83
101%6
1013
101
1013
1014
1014
lOI
1014
101
101
101
101 i
1014
1014
205

46
46
65

7734
77%3


77%
7731
77A
77%4

77
77%
77%(j



18

8930


85
85
85
85
121
121
151
151
181
217
217
217
220 o
220 34
220 4
220)
249
249
26

46
25
05
26
90
90
90
90
13634
1864 3


14534
14,534
129
150
2173
35

70


10.32
10.20
10.22
9.76
16.31
15.68
10.97
10.08
6.91
10.20
10.10
10.00
8.48
8.36
8.32
8.27
7.57
7.41
11.62

20.6
4.10
7.9
9.14
13.68
7.60
4.02
2.67
4.21
2.72
4.50
4.55
2.88
7.10
3.19
2.00

8.00


Undifforontiatod

Sands and clayn
do
do
do
Crystal River
do
Williston
do
Inglis
Avon Park
do
do
do
do
do
Avon Park
do
do
Clayey sand

Sand
do
Sand and clay
Sand
Crystal River
do
do


Inglis






Avon

Suwar


Measurement made before work started; all
maonurements made by F. W. Meyer;
FGS well number W-4990
After 30 minutes of rest
After 39 minutes of rest
After 41 minutes of rest'
After 57 minutes of rest
After 14 minutes of rest
After 20 minutes of rest
After 16 minutes of rest
After 21 minutes of rest
Before work started
After 24 minutes of rest
After 26 minutes of rest
After 28 minutes of rest
After 46 minutes of rest
After 50 rhinutes of rest
After 52 minutes of rest
After 55 minutes of rest
After 81 minutes of rest
After 68 minutes of rest
After 18 minutes of rest; FGS well number
W-5046; all measurements made by F. W.
Meyer
After 10 minutes of rest
Sand heaved into well, before work started
Sand heaved into well, before cleanout
After 32 minutes of rest


do Before work started
After 84 minutes of rest; from 125 to 1860 a
feet cavern fill, sand and clay
do From 186 34 to 160 ;3 feet cavern fill of sand;
before work started
do In honeycombed limestone; after 68 minutes of
rest
do After 71 minutes of rest
do All measurements made by author; sand filled
well to 129 feet; before work started
Park After 67 minutes of rest
do After 65 minutes of rest
inee All measurements made by author; measure-
ments after bailing; FGS well number
W-5352
do Measured after bailing













U8GS Date of
well measure-
number ment

813.201-1 7-31-50
(Cont'd) 8- 3.50
8- 3.50
8- 3-50

8- 3-50
8- 4-50

8- 4-50
815-187-2 8- 7-56
3- 7-56
8- 7-56
8- 7-56
3-15-56
4-30-56
8. 4-50
8- 4-50
8- 4-59
8- 5-56
8- 5-59
816-146-1 5-14-58
5-14-88
5-14-58
5-14-58
5-14-58
5.-14.58
5-15-58
5-15-58
5-16-88
&-16-58
6-6--68
5-16-58


to
TABLE 7 (Continued) 0)


Depth to water
Depth of casing Depth of well below land Geologic
(feet) (feet) surface (feet) Aquifelr formation Remarks


30
300
301
30s

309t
301
304i
41
41
41
41
41
41
41
62
62
52
62
82
82
82
82
82
82
82
82
82
82
82
82
82
82


245
246
252
51
103
108
108
108
74
71
110
150
164
108
145
175
181
199
232
277
277
297
312
322
332
389
401


2.60
2,20
2.45
2,33

2.38
2.23
2,28
6.77
6.08
3.77
3.63
3.34
4.00
1.08
1.20
1.22
1.11
1.21
3.88
5.61
6.09
4.93
5.03
4.80
3.91
5.17
4,18
4.31
3.89
4.32
4.23


do
do
Crystal River
Inglis

do
do
do
Suwannee
Crystal River
Wflliston
do
do
do
do
do
Inglisdo
do
do

Williston
Inglis
Avon Park
do
do
do
do
do
do
do
do
do
do


After 54 minutes of rest
Before work started
After 5 minutes of rest
After 65 minutes of rest; from 105 to 200 feet
no cuttings returned; from 200 to 210 feet
honeycomb-few cuttings
After 14 minutes of rest; from 234 to 235 feet
cavity; few cuttings
From 244 to 245 feet cavity; before work
started
After 32 minutes of rest
After balling; FGS well number W-3820
After bailing
After 28 minutes of rest
After 36 minutes of rest
Periodic water-level measurement
Periodic water-level measurement; well filled
to -74 feet with clay
Before work started
After 61 minutes of rest
After 8 minutes of rest
Before work starts
After 33 minutes of rest
Before work started* small cavity reported at
145 feet; FGS well number W-4689
After bailing
After 40 minutes of rest
After bailing
Do
After 13 minutes of rest
Before work started
After bailing
After 9 minutes of rest
After 25 minutes of rest
Before work started
No cuttings returned; 8-Inch cavity
After 20 minutes of rest; sand cavity fill from
389 to 401 feet






REPORT. OF, INVESTIGATION No. 44


gate in a northwest-southeast direction, generally following the
major trends of the geologic structure and central highlands.
Farther to the southeast, in southern Highlands County (Bishop,
1956, fig. 10, p. 44), this elongation appears to lose all definition.
The broad northern part of the piezometric high, occupying
all of the county north of Lakeland, Winter Haven, and Dundee,
represents the highest part of the piezometric surface in peninsu-
lar Florida. From this area the surface slopes downward in all
directions. North of Polk County the dome-shape of the piezomet-
ric surface becomes elongated along a northward trend through
Lake County. Throughout much of this northern elongation, the
dome is more specifically a well-defined ridge, as shown by Pride
and others (1961, fig. 22). The measurements used in constructing
their map were made concurrently with those for figure 20.
The many troughs in the contours are believed to represent
drawdown, or reduction of pressure-head, in the aquifer due to
horizontal flow through fracture-controlled cavern systems. These
piezometric troughs widen down-gradient. It appears that such
systems are branchiate up-gradient in the Lakeland area, and
they indicate integrated subsurface drainage systems (caverns)
of great areal extent and influence. For example, the trough
underlying Boiling Spring in Hillsborough County may be traced
up-gradient to the east and northeast through the Lake Hollings-
worth and Lake Parker areas, into the southwest edge of the
piezometric high.
A broad plateau-like feature of the piezometric surface oc-
cupies much of the southwestern part of the county, and is gen-
erally enclosed by the 90-foot contour. This area is separated from
the main portion of the piezometric high by a trough along the
Peace River on the east, and by another broad east-west trough
through the Scott Lake area south of Lakeland. The general
trough along the Peace River is caused by upward leakage and
artesian flow along the river valley. The trough south of Scott
Lake may be due to flow through solutional caverns developed
along a major fracture zone and the heavy pumping indicated in
that area.
Figure 21 shows the piezometric surface of the Floridan aqui-
fer in northwestern Polk County in 1956. The depression in the
piezometric surface along Saddle Creek is probably caused in part
by upward discharge into the secondary artesian aquifer which
in turn was discharging water from artesian springs into the





FLORIDA GEOLOGICAL SURVEY


Figure 21. Piezometric-contour map
Polk County (June 1956).


aquifer in northwest


of the Floridan






REPORT OF INVESTIGATION No. 44


mine pits (point E,. fig. 17). This is shown by the general coinci-
dence of the piezometric surfaces in an indefinite area along U.S.
Highway 92 for about a mile on either side of Saddle Creek. In
1960, long after cessation of such spring discharge, the general
re-entrant continues to exist in the piezometric surfaces of both
aquifers, and is shown in figures 18 and 22. Figure 20 shows that
the re-entrant is part of an really extensive piezometric trough
which underlies all of the Saddle Creek-Peace River valley in this
county. This indicates a general zone of upward leakage from
both aquifers into Saddle Creek and the Peace River and the per-
ennial swampy areas along their courses. The altitude of the creek
bed is 105 to 107 feet at Highway 92, and the creek stage ranged
from 0.15 to 1.90 feet above zero flow.
Figure 13, a map of the water table in the Lake Parker area
in 1956, is similar to the piezometric maps of the artesian aquifers
mentioned above. The contours of the water table reflect a general
trough along the creek as a result of discharge into the mine pits
and the creek.








...... .
















Figure 22. Piezometrie-contour map of the Floridan aquifer in Lake
Parker area (October:1959 to February 1960).
'25 C
05'~:~ ~








FiueM izmtrccntu'mp fteFlrdn qie i Lk
Pakrara(ctbr.95 oFeray-16)






FLORIDA GEOLOGICAL SURVEY


AREAS OF ARTESIAN FLOW
Figure 20 also shows areas in which flowing wells may be ob-
tained in the Floridan aquifer. The highest artesian head observed
during the period of measurement was 23 feet above land surface
at the public boat landing on the southwest shore of Lake
Weohyakapka in the southeastern part of the county.
Flow is indicated along the Peace River valley but does not
extend north of Kissengen Springs. Upward leakage from the
aquifers into the bottom of the river near Lake Hancock, much of
Saddle Creek, and soil zones of the valley floor during part of the
year, seems certain. The artesian pressure, however, is generally
insufficient to produce flowing wells in these areas. A small area
along the Withlacoochee River, in the area of limestone outcrop,
is also an area of intermittent artesian discharge. Most of this
occurs as diffused leakage rather than noticeable flow.
The map indicates that most of the large lakes on the lowland
east of the Lake Wales ridge are partially supported by upward
leakage of water from the artesian aquifer, and that ground water
is also being discharged into the Kissimmee River over much of
its reach.
WATER-LEVEL FLUCTUATIONS
Figure 23 shows hydrographs of wells open to the Floridan'
aquifer. These are wells in the network of permanent observation
wells in use by the U.S. Geological Survey. Annual water-level
records of these wells have been published in the Water-Supply
Papers of the Geological Survey under the well numbers Polk 44
(810-136-1) and Polk 45 (759-158-1). Additional water-level data
from wells in this aquifer have been published by Stewart (1963,
table 7). It is evident that there is general correlation of the hy-
drographs, though considerable differences in the range of fluc-
tuation exist. Most of the deviations in correlation are caused by
effects of pumping. Seasonal trends, however, correlate well.
The range of water-level fluctuations in wells penetrating this
aquifer differs widely over the county. Recharge and pumping
cause the greatest fluctuations in the aquifer. The records of 10
wells, including those shown in figure 23, show net changes from
highest to lowest water level of record of 2.2 to 17.8 feet in -in-
dividual wells. The greatest total annual fluctuation ranged from
2.8 to 10.6 feet in individual wells, and did not occur during the
same year.
In general, the least amount of fluctuation occurred in wells
located nearest the top of the piezometric high, and the greatest


100








REPORT OF INVESTIGATION No. 44


+6







0


-2


-4
0
S -6


-58
o

-60


- -62

a)
. -64
E
S-66

-68


3 -70


-72


-74


-76


-78


101


-80-I I-, I Ii I- I I---
:1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959

Figure 23. Hydrographs of fluctuations of piezometric surface in a well
near Lakeland (759-158-1) and a well near Davenport (810-136-1) in the Flori-
dan aquifer.


Well 810-136-1, 5 miles N. of Haines City (Floridan aquifer)



Apl_ A'A

------ -I-- vY-






FLORIDA GEOLOGICAL SURVEY


occurred in the areas down-gradient. The ranges of fluctuation
were greatest in the heavily pumped areas at Lakeland, Winter
Haven, and at the phosphate mining area of the southwestern part
of the county.

WATER-LEVEL HISTORY
Few data are available on water-level fluctuations in Polk
County before 1948. The records shown in figure 23 constitute the
longest continuous records in the county.
Stringfield (1936, p. 172) lists water-level measurements
made in a number of wells that were also observed during this in-
vestigation. Representative data from these wells are presented in
table 8 for the purposes of detecting long-term trends. Stringfield's
measurements were made during a period that was preceded by
11 years of above-normal rainfall. The 1956 measurements were
made after 21/2 years of below-normal rainfall, and the 8- to 20-
foot indicated decline from 1934 is not considered permanent be-
cause of the substantial difference in antecedent conditions. The
1959-60 measurements were made after a year of above-normal
rainfall, and they indicate an apparent net decline from the 1934
levels ranging from 0.3 feet to 12.3 feet.
Figure 20 indicates that the plateau-like area in the south-
western part of the county is one of great ground-water pumpage.
Such pumpage is largely associated with the pebble phosphate in-
dustry, and it is of relatively large magnitude and long duration.
Reports of artesian flow and water-level data by Matson and San-
ford (1913, p. 389-391), by Sellards and Gunter (1913, p. 263),
and by Peek (1951, p. 80), indicate that water levels have de-
clined from 5 to 20 feet in the past 45 to 50 years in this area.
Sellards and Gunter (1913, p. 364) report the water level in the
Mulberry city well as being-approximately 21 feet below land sur-
face in 1907-1908. This well is 753-158-2 of. this report, and it
could not be measured during this investigation. However, in well
753-148-1, approximately 50 feet away, the water level was 35.3
feet below land surface on January 25, 1955, and was 30.1 on
December 21, 1959; an apparent net decline of 9 to 14 feet in 51
years. Such declines are largely attributed to steadily increasing
pumpage by the phosphate industry. If all industrial pumpage
would cease in this area, it is likely that the piezometric surface
would recover rapidly.
Only one well at Loughman (814-133-1) in the northeastern
part of the county showed essentially no change from the 1934


102












TABLE 8. Net change in water levels in wells in the Floridan aquifer, 1984-59
(Water level in feet above msl)

Well no. Apparent Altitude of water level observed Length of record
Well W.S.P. General not change in this investigation during this
number 778-C location Date Altitude' Date Altitude Date Altitude in feet Highest Date Lowest Date investigation
744-181-4 Po-41 Frostprocf 9/21/84 82 .... .. 2/ 4/58 792 3.0 ... .... .... .... One observation
745-146-1 Po-89 Ft. Meade 0/20/34 101.3 7/12/56 86.9 1/22/60 9.5 7.8 08.0 10/23/59 82.8 8/16/56 4/5/55-2/5/60
745-158-6 Po-37? Brewster 1/ 9/84 97.0 7/12/56 77.1 1/22/60 84.7 -12.3 88,3 10/26/59 71,7 8/15/6 4/5/55-2/8/60
756-185-1 Po-32 Mountain Lake 9/20/34 115.4 2/16/55 106.0 12/11/59 107.8 7,6 .... ..... Two observations
758-145-1 Po-22 Eagle Lake 7/28/84 122,8 8/31/58 114.0' 12/17/59 111,88 -11.0 .... ...... Two observations
801-148-1 Po-20 Winter Haven 1916 185 7/12/56 123.7, 12/ 1/59 125.8 127.5 9/ 2/57 117.4 5/ 3/56 7/1/55-2/5/60
802-157-8 Po-11 Lakeland 8/15/84 116.0 7/ 6/56 106.1 1957 (Well ... .... One observation
(Pumping destroyed) '
808-188-2 Po-10 Lakeland 2/29/34 111.0 7/ 2/56 105.4 11/19/59 100.74 -10,3 ...... Two observations
804-147-2 Po-15 Auburndale 3/15/34 128.1 6/25/56 118.7 11/23/59 128.1 5.0 124.0 10/14/64 .... .... Three observations
805-144-1 Po-16 Lake Alfred 7/20/34, 11.5 9/27/57 129.1 11/ 859 129.7 1.8 .... .... Two observations
814-188-1 Po- 8 Loughman 3/16/84 98.5 11/26/57 92,7 11/ 2/59 93,8 + .3 93.8 11/ 2/59 92.7 11/26/57 Five observations

I Depths to water adjusted to measuring point and altitudes of this investigation
2 Measurement made in 744-181-6, approximately 28 ft southeast of Po-41
Well re-worked and deepened in 1954 '
4Measurements made in 808-158-1 (Po-9), approximately 40 ft southeast of Po-10







FLORIDA GEOLOGICAL SURVEY


measurements. That community has not grown materially since
that time and there has been little change in the local ground-
water regimen. A part of the apparent net change in the Frost-
proof area may be due to heavy local pumping at the time of
measurement in 1958. It seems likely that the areas of greatly in-
creased pumpage in the central and southern parts of the county
have not materially affected the water levels near the top of the
piezometric surface. In those areas, because of lowered water
levels and increased hydraulic gradients between aquifers, local
recharge has been increased and is now supplying present de-
mands. In the southwestern part of the county, the plateau-like
shape of the piezometric surface indicates that local pumpage is
nearly equal to available local recharge, and hence the general
flattening of the surface.
In evaluating declines of water levels in the county, several
other factors must be considered. First, observed declines of water
levels do not constitute de-watering of the aquifer, but rather a
reduction of pressure within the artesian system. Hence, should
pumping cease for even a short time water levels would rise
radidly as artesian pressure was restored. The water is not being
"mined," or permanently removed. Second, each series of measure-
ments shown in table 9 show seasonal variations. In Polk County;


TABLE 9. Specific capacities of wells in Polk County

Well Number
diameter of (gpm per foot of drawdown)
(inches) wells Highest Lowest Median Average
30 2 615 136 375'
24 5 518 51 180 228'
20 6 2,500 31 8371 1.039
18 8 833 139 2861 338
16 9 2,700 59 2381 5661
15 5 417 78 2221 2191
12 31 2,500 14 1201 2811
10 34 1,000 18 100 189
8 24 750 18 671 1221
6 20 109 6 251 371
4 16 35 1 13' 14.31
3 13 48 1 6' 13.6

SIncludes multiple tests in some wells


water levels follow the generalized pattern of decline during the
winter and spring months, and rise during the summer and
autumn. The preceding hydrographs and discussion of ranges of
water-level fluctuation show that water levels are constantly
changing in a given well, and that the range of relatively short-


104







REPORT OF INVESTIGATION NO. 44


term fluctuations is often equal to the apparent long-term net
decline of the piezometric surface.
HYDRAULICS
SPECIFIC CAPACITY OF WELLS
Meinzer (1923b, p. 62) defined the tested capacity of a well as
"the maximum rate at which it is known to have yielded water
without appreciable increase in drawdown." He defined the spe-
cific capacity of a well as "its rate of yield per unit of drawdown"
and stated that "the term is applied only to wells in which the
drawdown varies approximately as the yield. In such wells, the
specific capacity can be estimated by dividing the tested capacity
by the drawdown during the test." Many specific-capacity tests
have been made by local well drillers. A summary of these are
shown in table 9, and the test data are shown in table 10.
Generally, the diameter of the open-hole portion of wells is
drilled to about the size of the inside diameter of the smallest
casing, and for the purposes of table 10, this is assumed to be the
case in all wells for which data are lacking. In large diameter
wells (20- to 30-inch) such is not always the case. For example,
well 805-153-4 was drilled to 15-inch diameter in the open hole
with a 30-inch casing.
It is the general practice among drillers to pump the finished
well until the water is clear. In 12-inch wells, and larger, it is
common practice to run the pump for 4 to 8 hours. This procedure
not only clears the water, but determines the tested capacity of
the well. For the purpose of table 11 it was assumed that such
was the case, even though the drillers did not report the duration
of the tests.
The data of table 9 establish two factors of great importance
to the hydrology of the county, and to the more theoretical con-
cepts of hydraulics and movement of water within the aquifer.
They are (1) the specific capacity of wells, and hence the trans-
missibility of the aquifer, are not primarily controlled by the
amount of open hole in the well or the total depth of the well, and
(2) they are not primarily controlled by the well diameter. The
data show that some of the lowest capacity wells have substan-
tially more open hole than the highest capacity wells of a given
diameter. Similarly some 8-inch wells are shown to exceed 15-,
24-, and 30-inch wells in specific capacity.
The occurrence of the cavern systems permits very localized
zones of high transmissibility within the aquifer, and closely ad-


- --" s I


105









T''lLn 10, Spooiflo capadltio of wells in Polk County


Diameter Depth Dlepth Statio water
of largest of of level below Puminplg 8peallio Pumplng
Well oaelng euaing well hlind surface Drawdown route capacity time
number (inlchea) (feet) (feet) Aquiferl (feet) (feet) (gpml) (gpan per ft) hour') Remarks'


JSOineh well:
748-148-2
751-148-1


30 unknown 800 3 62 22 3,000 130 1
80 03 010 2,3 33 13 8,000 015 1


18-foot cavern


4itinch well:
769-156.1 24
800-158-3 24
802-157-10 24
807-1644 20
808-168-2 20
0O-ineh w lls:
748-148-8. 24
761-185-2 24
751-165-3 20

754-164-1 24
76-166-2 24
808-184-35 20
18-inch well!.
744-157-2 30
748-148-6 24
760-161-2 24
781-169-1 24
784-186-1 20
802-188-1 18
803-157-1 18
806-152-1 24


1,220 3
1,037 3
1,210 3
1,198 3
575 3


- 740
330 788,
344 832


311 820 3
380 721 3
804 030 3


20
15
83
14.7
16


50
16
48
11.0
20,0


12 13
100 8
08 2
2
5
128 4
132 13
27 32


852
800
909
889
1,156
726
806
715
1,286


0
10
21
10
60
13.5
11
62
665


5,000 100
2,700 180
2,435 61
0,000 518
0,000 202

5,000 386
6,200 050
4,500 2,260
6,000 2,500
.5,800 1,160
4,100 1,025
4,000 308
],000 31


7,600
0,000
0,000
3,500
3,5560
2,000
2,750
7,260
4,000


2-toot cavern
Do
2-foot cavern; test measured by USGS



18-inch cavern



Total depth of completed well is 860 ft


Two 4-foot and one 10-foot cavern


One 3-foot and one 4-foot cavern
Reports numerous "gravel beds"


10 107 430 3
24 230 759 3
10 800 1,202 3
20 886? 003 3
10 101 650 2,3
20 96 083 2,3
10 332 764 8
20 88 750 2,3


8
8.5
151
84
36
28
82
00


Not
measurable
21.5
24
19
3
4
13
8


2,700 >2,700


4,000
1,400
2,000
1,600
2,500
2,100
2,600


214
684
106
500
025
102
834


Sand-filled caverns
foo
4-foot cavern


10-inch wells:
744-131-0
745-145-1
748-181-1
768-150-8
758-151-1,
768-151-2
76-1688-1
164-162.4.
,* \





768-153-1 20 112 017 3 31 8 1,000 288 1 2- oot avorns
759-144-2 20 407 000 3 24 0.0 8,960 000 20 Probable 3-foot cavorns
806-137-9 10 148 803 3 01 0.6 1,768 184 1 6-foot cavern and 10-foot cavern ill


16-inch, wells:
758-160-2
800-165-1
802-167-10
802-157-11



805-153-4 .


1A-inbch tells:
742-182-1
742-160-1
748-148-
744-143-1
744-157-1
'746148-83
761-188-2
752-14-6-5
752-2b1-2
763-184-2
7683-1605 '
753-16584
754-136-8
764-186-10
754-147-8
764-182-2
76544512-3
767-1'401
:'800-188-1
,801-143-2
802-148-1
802-143-2
802-148-8
802-146-1

802-146-2

802-157-4


700 706
750 1,030
260 741
360 760
850
1,000
1,201
1,201
105 1,198


20
30
9
20.5
14
10
6
15
0
12
23


12 317 1,113 3 02 19
20 444? 812 3 0 10
20 880 840 3 44 5
12 145 178 2 Not
measurable
16 687 970 8 80 6
20 871 830 3 58 5
12 900 3 28 4
16 410 775 3 119 10
12 270 800 3 37 7
18 790 1,063 3 135 4
12 93 742 2,3 49 75
16 264 776 3 32 18
16 1,116? 1,200 8 14 14
16 408 718 8 26 41
12 281 781 3 50 22,5
18 290 1,085 3 59 11
18 284 830 8 61 18
12 124 663 3 22 18
12 107 600 3 4 12
12 140= 648 2,3 27 5
12 147 503 3 27 9
12 188 810 3 27 7i
12 145:: 042 3 27 1.2
12 185 001 8 37 9
11
18
12 165 040 3 40 15
16
18
12 390 3 21


15
20
15
18



30


100
133
222
78
114
160
267
200
417
808
347


2,000
400
2,000
1,600
1,600
1,600
1,600
4,000
2,600
3,700
8,000

1,000
5,000
8,200
1,400
2,000
1,500
1,100
1,230"
1,700
1,600
S1,063
1,500
1,000
1,000
1,212
1,220
1,200
1,000
1,500
1,017
927
020
972
900
1,300
1,500
1,500
1,600
1,700
800


334
800
276
123
243
400
141
83.5
71.5
24.4
52.9
120
06,0
66.6
55 5
125
188
103
323
810
100
118
83.5
100
100
94.6
14.8


Loss of circulation





8-foot cavern

Two 2-foot caverns

4-foot cavern plus smaller openings
"Honeycomb" zone
Loss of cuttings


Honeycomb zone
Do
2-foot cavern

7-foot cavern
Loss of cuttings
"Well ends in series of small caverns"


I
*
1M4




0




,0



I
C.,

0


}4 Well ends in lower part of Euwannee
Limestone or upper part of Crystal
River Formation.


1(1) Nonarteaian (2) Secondary (8) Floridan
0 All data are "reported" unless otherwise shown.


62.7 1
312 1
040 1
>1,500 1


1


:I!j



''
..r
.;I




i,
r


J
'' '








T'AI.4I 10, Hpocifio cuualp ties of wells in Polk County (Continuo l)


Diameter De th Depth Statio water
of largest o of level below Pumping Speciflo Pump'ng
Well easing cang well land surface Drawdown rate capacity time
number inchess) (feet) (feet) Aijulfer' (feet) (feet) (gpll) (gpn per ft) (hours) Roemarks'


804.147-2
806-146.4
805-147.8
809-180.5
809-140.1
10.inOh well;
789.121-1
789-121-3
744-181.3
748-148-2
7474015-1
747-108-2
748-141.1
750-1514'
751-148-2
781-146-.1

752-14i1.3
752-20143
758-1i9-2'
7584-142.2
754-184-1
754-135-A?
756-183-8
707-1i83:
757-15&-7
759-148-2
801-180-1
801-155-1
802-157-8
808-148-1
808-147-4
805-144"1
806-187-2,.
806-187-7:


Well ends in 20-foot cavern


81
83
100
401
122

280
202
70+
284
120
114
93
109
289
157

185
0-177
235-275
155
102
400
652,
150
208
253
218
255
120
300
175
344
74
190
102


100
558
502
520
500

1,000
1,035
1,040
708
803
30
725
150'
738
812
330


12 i
3U
10
22
40

+10.4
+10
20
55
02
45
80
27
08
121
100

59
37
38
47.
140
42
20
30
175
14
44
80
90
8
44
19
01
10


I f

7
30

10.2
30
17
15
7
23
20
4
10
10
20

20
7
20
15
20
Not
neasurablo
10
10
4
80
Not
measurable
25
5
10
1.3
10
6


719 3
'740 2,3
802 3
720 2,3
1,225 3
1,010
210
597 3
845 3
662 3
1,327 3
560 .
019 3
605 3
016 3
150 27,3
550 3
490. 3


450 300
000 300
2,600 2.500
1,520 218
1,31U 44

450 44
400 133
1,200 71
500 33.3
1,20(1 172
101 7
1,400 70
100 25
1,500 160
1,285 128.5
350 17.5

1,200 00
1,700 243
1,500 75
2,000 133
800 40
1,500 273
1,000 >1,000
800 80
900 90
1,100 275
1,000 33,8
750 >750
750 30
500' 100
1,140 71.5
250 192
1,500 150
300 50


Well apparently ends ih lower Crystal
River formation



Well apparently ends in lower part of
Suwannee limestone or upper part of
Crystal River Formation
11-foot cavern fill
One 5-foot cavern and smaller ones



2-foot cavern
8-foot cavern fill
Several 1- and 2-foot caverns



"Honeycomb" zone
1-foot cavern fill


I








"Gravel" zone


Well ends in 10-foot cavern


800-142-1
810-140-1
810-153-1
810-154-1
817-150-1
8-.inhOh wells:
744-181-2
744-181-4
,744181-5
;745-148-1
747-837-1
747-142-1
750-143-1
',754143-1
,752-142-8
S752-150-4
S.,758-142-3
.758-140-2
'758-155-1
754-152-1
'754-159-3
756-188-1
759-201-1

759-201-2
802-187-1
802-157-9
,808-147-8
'806-187-5
806-1837-0
.810-149-2
O-inch wills:
S745-145-2
746-148-2
747-200-1
. ,751-188-1
754-187-1
755-131-1


118
20
44
246
152

588?
168
191
0-156
845488
806
108
105
118
'207
105
120
296

80
72
156
176

108
121
300
210
92
107
100


57
625
9760
286
112


S(1) Nonartisian (2) Secondary (3),Florldan
2 All data are "reported" unless otherwise shown.


1,060 3
254 3
425 8
852 2,8
959 3
265 2
725 2,3
465 2,3
750 3
.186 2
720 2,3
575 3
375 2?,3
188 2
230 2,8?
534 8
071 2,3


12
7
11
10
88

5
+1,6
+1.6
118
87
55
80
75
57
55
5s
20
98
45
84
12
87

36
4
90
41
20
42
32

9
42
48
88
38
9
13


3
Not
measurable
9
11
Not
measurable
9
Not
measurable
2
15
6
20
15
15
15
10
40
2
17
20
2
9
18
21
1.2

4.5
6
25
14.5
Not
measurable
30
33

11
10
17
15
35
8
10


500
750
1,000
1,100
800

750
760
650
1,200
1,060
800
600
600
1,200
608
700
850
800
850
120
567
700
860
500

600
500
600
1,600
140
2,100
1,241

84
60
450
800
600
120
100


100.0
>750
ill
111
100
>800

83.5
>750
325
80
177
40
40
40
80
.60.8
17.5
175
17.0
17.5
60
03
54
41
416

111
83.3
24
111
>140
70
37.6

3.1
6
26.5
538
17,1
15
10


683
405
619
048
423
810
547


140 2
222, 2
600 2?,3
990 3
1,080 3
588 3
420 2,8


Both wells started with 10-inoh easing,
but finished with 8-inch to land sur-
face
5- foot cavern


4-foot cavern


89-foot honeycomb zone


0








'0


I-
0,







'I'Au.l 10 10. Fl)(pilli cuapicitie of wells in Polk County (Continued)


Diameter Depth Depth Statio water
of largest of of level below Puiling Bpeciflo Pumping
Well casing casi|n well land surface Drawdown rate capacity time
number inchesa) (foot) (feet) Aquifer' (feet) (feet) (gpm) (gpm per ft) (hours) Remarks'


12 570 1,025
8 151 645
0 101 325
0 231 710
0 181 570
0 130 315
0 158 388
8 445 575
6 202 201,
8 407 0065
0 53 411
0 88 198
0 43 385
10 82 401


766-134-2
7W8180-1
802-167-14
802-167-16
803.154-33
803-186-13
803-160-10
805-187-2
805-150-1
806-138.2
807.164-3
807-201-1
809-153-1
816-146-1
4-inch welli:
742.200-1
748-128-1
767-168-8
801-138-1
801-202-3
802-151-10
802-161-12
802-161-14
808-145-1
808-145-2
803-161-0
803-153-29 .
803-158-14
805-153-3
(805-155-2
805-167-17


18. 1
015 2,3
95 2
250 3
90 2
325 2,3
248 2,3
265 2,3
215 3
155 2
239 2,3
15.4 2,3
99 2,3
125 3
311 3
145 3


170
15
122
112
24
48
57
72
105
12
14
44
15
5

4.5
.3
0
0
13
12
17.4
18.2
24
18
13.7
15.3
19.1
10.3
17
27.0
46


11
140
10
12
2
10
5
10
0
15
3.4
10
11.25
15

10
25
5
20
8
3.25
4
2.75
0.2
15
2.0
5.7
4.3
Not
measurable
13
1.6
Not
measurable


1,200
600
250
500
150
200
125
000
125
460
200
200
300
1,020

100
30
30
300
75
00
85
35
50
100
40
100
05
35
100
17,
17


100
15
25
41.0
75.0
20.0
25.0
90.0
13.9
30.0
85.5
20.0
20.0
68.0

10.0
1.2
0.0
15.0
9.4
27.0
21.2
12.7
5.5
0.7
23.0
17.0
15.1
>85.0
7.7
10.0
>17.0


Well ends in Crystal River Formation
or lower part of Suwannee Limestone
Loss of cuttings
Well apparently ends in Crystal River
Formation
Do
Well apparently ends in Crystal River
Formation
)I Measured by author
Well ends in Suwannee Limestone; 2-
foot cavern
1 Measured by author
1 Measured by author; small open cav-
erns; well ends in 14-foot cavern fll
)i Well is not screened; measured by au-
thor



ii Measured by author
3 Do
li Do
Cavern; no dimension given
2-foot cavern and loss of cuttings
i Measured by author
9 Do
1 Do
.4 3-foot cavern

34 Well ends In lower part of Crystal Riv-
Ser Formation; 2-foot cavern
1 Well ends in Suwannee Limestone


4 10.
4 108
4 53
4 142
4 66
4 42
4 35
4 45
4 87
4 101
4' 48
4 00
4 45
0 91
4, 82.4
4 134







3-inch wells:
747-158-1
759-155-4
802-182-10
803-148-5
808-151-6

808-183-20
804-152-2
804-153-13
805-168-2
806-156-2
807-154-2
808-158-1
815-167-2


100
265
65
160
167
193
125
59
59
72
108
56
98
108


1 (1) Nonartesian (2) Secondary (3) Floridan
2 All.data arc "reported" unless otherwise shown.


Il



0e

I-


10
8
10.2
18

10.6
19.4
14.8
12.7
17.6
23.7
7.7
18.0
7.1


10 20
5 80
1.8 60
4 10
8.0 55
9.2 556
2.2 28.
.6 29
4.6 24
2.8 24-
.6 22
4.0 24
4.0 24
22.2 18


2.0
6.0
83.8 1 Loss of cuttings; measured by author
2.5
6.2 2)f Measured by author- well ends in top
of Crystal River (?) Formation
6.0 1i
12.7 13. Measured by author; well ends in Su-
wannee Limestone
48.4 .6 Measured by author
8.3 6 Do
8.6 it Do
86.7 .1 Measured by author; Honeycomb zone
6.0 6 Do.
6.0 .6 Measured by author; well ends in upper
part of Suwannee Limestone
.8 1 Measured by author; small caverns and
much cavern fill






FLORIDA GEOLOGICAL SURVEY


jacent areas of relatively very low transmissibility. The disparity
of specific capacities of adjacent wells is brought about by con-
ditions like that shown in figure 10. Thus, a change in drilling
location of a few feet could produce entirely different hydraulic
characteristics of the aquifer.

VERTICAL MOVEMENT OF WATER
Traverses were made in three wells with a current-meter to
determine if interchange of water was occurring within and be-
tween the various units of the aquifer. Traverses were made under
static conditions in wells 757-152-1 and 805-157-16 without de-
tection of vertical movement. These wells are open to all units of
the Floridan aquifer. Two traverses in well 805-155-2 were made
under static conditions and vertical movement of water from the
secondary artesian aquifer downward into the Floridan aquifer
could not be detected. The secondary aquifer in this well is 111/.
feet thick, and the well was open to 1731/ feet of the Floridan
aquifer at the time of the tests. The observed difference in head
at the time of drilling was approximately 6 feet. Because of the
disparity in thickness and the generally observed disparity in
permeabilities, the discharge of water from the secondary aquifer,
down into the Floridan aquifer through the well bore was not
detected.
A third traverse in well 805-155-2 was also made while the
well was being pumped at about 20 gpm. The pumping rate was
too low to detect vertical movement in the well bore.
The tests show that there is free circulation of water and
equalization of artesian pressure within the aquifer in Polk
County because the hard, low permeability zones in the different
formations are highly fractured.

PUMPING TESTS
A pumping test was made in well 807-154-4 on July 9, 1956,
to determine the coefficient of transmissibility of the Floridan
aquifer at one location in northwestern Polk County. The co-
efficient of transmissibility (T) is a measure of the capacity of
an aquifer to transmit water. It is the quantity of water, in gpd,
that will move through a vertical section of the aquifer 1-foot
wide and extending the full saturated height under a unit hydrau-
lic gradient.
Well 807-154-4 is northeast of Lake Parker (fig. 22) and is


112










TABLE 11. Hydrologic properties of limestone core samples from well 805-154-81

Depth
(feet)
Laboratory Field Dry unit Specific Specific Coefficient of
sample sample Geologic weight retention Porosity yield permeability
number number From To formation Lithology (g per oo) (percent) (percent) (percent) (gpd per sl ft)'

60 FLA 39 1 71.8 72.4 Suwanneo Limestone, tan, fragmental, 1.87 17.5 31.5 14.0 V 0.05
very soft H 0.
60 FLA 40 4 260 269.5 Crystal River Limestone, cream, chalky, co- 1.53 28.3 43.8 15.5 V 0.9
quina, soft H 1
60 FLA 41 5 282.2 282.5 Williston Limestone, tan, granular, hard 1.99 23.8 26.8 3.0 V 0.2
H 0.2
60 FLA 42 7 317.5 317.9 Inglis Limestone, cream, granular, 1.52 20.9 44.1 23.2 V 2
hard H4
60 FLA 43 9 447.5 447.9 Avon Park Limestone, tan to gray, highly 2.32 7.5 18.3 10.8 V 0.0001
dolomitized, very hard H 0.0006
60 FLA 44 11 519.5 519.8 Avon Park Limestone, brown, highly do- 1.98 11.3 30.3 19.0 V 12
momitized, highly porous H 11
60 FLA 45 14 1,001.9 1,002.5 Avon Park Limestone, white, very chalky, 1.68 29.1 41.3 12.2 V 0.4
very soft H 122
60 FLA 40 16 1,169.5 1,169.9 Lake City Limestone, cream, chalky, with 1.85 13.5 35.1 21.6 V 15
selenite impregnation, soft H 19
60 FLA 47 17 1,386.3 1,386.6 Lake City Limestone, tan, highly dolomi- 2.34 10.8 19.6 8.8 V 0.0003
tized, hard H 0.004
60 FLA 48 19 1,476.8 1,477.3 Oldsmar Limestone, gray-brown, highly 2.42 15.2 15.4 0.2 V 0.02
dolomitized, with selenite im- H 0.02
pregnation, and gypsum and
anhydrite nodules

Analysis by USGS Hydrologic Laboratory, Denver, Colorado.
SV vertical, H t- horizontal.
*Sample was fractured at end of test. May have made permeability too high.


'i






FLORIDA GEOLOGICAL SURVEY


open to the Williston and Inglis Formations and the Avon Park
Limestone. The well is 26 inches in diameter, 1,198 feet deep, and
is cased to a depth of 292 feet. During the test it was pumped by
a diesel-driven turbine pump for 8 hours at a nearly constant rate
of 6,500 gpm. Total drawdown was approximately 111/2 feet. Com-
putations of the T were made from measurements of the recovery
of the water level in the well. The T for the part of the aquifer
open to this well was computed to be about 1 million gpd per foot.
Data collected from other wells indicates that the T of the upper
part of the Floridan aquifer is appreciably less than 1 million gpd
per foot, and that the transmissibility differs considerably in dif-
ferent sections of the aquifer.
The T determined from the test of 807-154-4 is substantially
higher than those determined by pumping tests in other parts of
central Florida. As a result of tests near Terra Ceia, Manatee
County (southwest of Polk County), Peek (1958, p. 49-56) finds
the T of 100,000 gpd per foot and a storage coefficient (S) of
1.1 X 10-4 to be generally representative of the Floridan aquifer
in that area. The tested wells, representing local well depths and
construction, penetrate thick limestone sections of the Tampa
Formation and Suwannee Limestone and reach a total depth of
650 feet, and are cased to 65 feet.
In the Ruskin area of Hillsborough County (west of Polk
County), Peek (1959, p. 47-54) determined that the T is 114,000
gpd per foot, and the S is 6.0 X 10-4. The test was made in wells
700 feet deep, cased to 65 feet, and open to the Hawthorn and
Tampa Formations, the Suwannee Limestone, and the Crystal
River Formation.
Menke, et al, (1961, p. 89-95) present results of several tests
in a well field west of Plant City, Hillsborough County, which is
the most comprehensive series of tests ever conducted in central
Florida. These tests indicate the T is 35,000 gpd per foot and the
S is 5.0 X 10-5 in the Tampa and Suwannee Limestones of the
Floridan aquifer. In a section composed of the Tampa Formation,
Suwannee Limestone, Crystal River, and Williston Formations, T
is 100,000 gpd per foot, and S is 3.0 X 10-4. The results of tests
using different pumped wells, but essentially the same observa-
tion wells and the same geologic section indicated a T of 50,000
gpd per foot and S of 7.0 X 10-4. Deepening the wells to include
all of the Ocala Group, Avon Park Limestone, and the upper 80
feet of the Lake City Limestone gave a T of 220,000 gpd per foot
and an S of 2.0 X 10-3. The two pumped wells used in different


114







REPORT OF INVESTIGATION NO. 44


tests are only 400 feet apart, and the data clearly show the differ-
ences which may occur within short distances in the aquifer.
Wyrick (1960, p. 50-62) describes pumping tests in Volusia
County (northeast of Polk County) in which the wells tested
penetrate only 9 to 233 feet of the Floridan aquifer. In the tested
area, the Floridan aquifer consists of a few feet of Williston, the
Inglis, and the upper part of the Avon Park. Results of the tests
show that T ranges from 28,000 to 370,000 gpd per foot, and S
ranges from 1.1 to 7.2 X 10-4. These wells do not penetrate the
dolomite zone of the Avon Park, which in Volusia County acts as
an impermeable bed and blocks internal circulation in the aquifer,
and thus permits the existence of differing heads in the two parts
of the aquifer.
The pumping test data all corroborate the general conclusions
reached in discussions of the specific capacity of wells in Polk
County-that the hydraulic characteristics of the aquifer are
valid only at the site tested, but that they may be applied to broad
general problems only with the knowledge that vast differences in
these characteristics occur in relatively short distances vertically
and horizontally.

HYDROLOGIC PROPERTIES OF SELECTED LIMESTONE
CORE SAMPLES
Ten core samples of limestone from well 805-154-8, a deep core
hole drilled northeast of Lakeland, were selected for laboratory
analyses of hydrologic properties. These samples are generally
representative of the differing lithologies encountered in the well.
Selection was also guided by apparent porosity and permeability,
and the sampling attempted to range between the most dense im-
permeable dolomitized zones and open cavernous zones. The results
of the tests, made by the U.S. Geological Survey Hydrologic
Laboratory, Denver, Colorado, are given in table 11. Both vertical
and horizontal permeability were determined for each sample. The
dry unit weight, specific retention, porosity, and specific yield of
each sample were also determined. The specific retention of a rock
is the percentage of its total volume that is occupied by water
which will not be yielded to wells. The porosity of a rock is the
ratio of the volume of the void spaces to the total volume of the
rock or aggregate sample. The specific yield is the percentage of
its total volume that is occupied by water which is yielded by
gravity to wells. The specific yield is equal to the porosity minus
the specific retention.


115






FLORIDA GEOLOGICAL SURVEY


The highest coefficient of permeability determined from the
core samples (field sample No. 16) is slightly less than the lowest
value obtained for sand samples in this area (Stewart, 1963, table
9). This indicates that gross porosity and permeability of the
limestones contributes very little water to a well, and that the
very high capacity wells are supplied almost entirely by penetra-
tion of significant solutional features. Many of the samples tested
contained visible solutional tubules or small cavities. The results
also show that in 7 of 10 samples, the horizontal permeability ex-
ceeds vertical permeability as is generally expected in layered
sediments. Horizontal and vertical permeabilities are equal in two
other samples, and are nearly equal in a third (field sample No.
11).


RECHARGE
NONARTESIAN AQUIFER
The principal source of recharge to the nonartesian aquifer is
local rainfall. Because of the high porosity and permeability of
this aquifer, there is only a small amount of direct surface runoff.
In low flat areas the aquifer is generally 3 to 20 feet thick, and
with above-normal rainfall, the aquifer may become saturated
in such areas. Under these conditions further recharge is rejected,
and ponding and direct surface runoff occurs. In the ridge areas,
however, the aquifer is as much as 250 feet or more in thickness
and ponding and surface runoff do not occur except for brief
periods during the most intense precipitation.
Thus, recharge to the nonartesian aquifer is essentially equal
to rainfall minus evapotranspiration. In much of the broad Saddle
Creek-Lake Hancock lowland the aquifer is only 1 to 4 feet thick
and surface gradients are very low. Perennially ponded swamp or
marsh conditions exist over much of the area, probably due
partly to upward discharge of water from underlying artesian
aquifers. Though the aquifer is thicker (10 to 50 feet) in much of
the county north of Lakes Lowery and Parker (fig. 14), topo-
graphic gradients are about 30 feet per mile, and surface drainage
is poorly developed. Perennial swamps and ponds exist over much
of that part of the county, and large additional parts of the area
are marshy or spongy and nearly saturated except in definite dry
periods. The swampy conditions in the northern part of the
county, therefore, reflect rejected recharge.


116






REPORT OF INVESTIGATION No. 44


All evidence in the county indicates that the water table in
the nonartesian aquifer is the true top of the zone of saturation,
and that unsaturated zones do not exist between it and the
rocks now known to constitute the Floridan aquifer (base of the
Avon Park Limestone).

UPPERMOST ARTESIAN AQUIFER
No data are available on recharge of the uppermost artesian
aquifer, but it is inferred from water-level relationships that the
aquifer is recharged largely, if not entirely, by downward perco-
lation of water from the nonartesian aquifer.

LIMESTONE AQUIFERS
The piezometric highs in figures 19 and 20 show that re-
charge to the secondary artesian and Floridan aquifers is occurring
over broad areas of the county. Because these aquifers are essenti-
ally buried by the nonartesian aquifer and other unconsolidated
deposits, recharge to them can only occur by water percolating
downward through the overlying deposits.
The approximate total amount of water recharging the sec-
ondary artesian and Floridan aquifers in Polk County may be es-
timated by subtracting runoff and evapotranspiration from rain-
fall. For these purposes the data of 1959 was used and it was
assumed that there was no change in storage. In arriving at the
total recharge, therefore, precipitation at the nearest Weather
Bureau stations outside of the county in each of the basins were
also used. Stations within the county, being nearer to the head-
waters areas of the streams, were given twice the weight of those
outside of the county. Out-of-county stations used were Clermont,
St. Leo, Hillsborough, Parrish, Wachula, Nittaw, and Kissimmee.
Runoff data from table 6 were assumed uniform over the basin
in the following computations. Evapotranspiration was estimated
to be 40 inches per year, in an earlier part of the text. On the
above criteria, the total water retained as recharge in each of
the river basins in table 6 during 1959 is as follows:

Alafia River basin:
Area: 149 sq. mi.
Runoff 34 inches Rainfall 75 inches
+ Evap. 40 inches Loss 74 inches
Loss 74 inches 1 inch recharge
1 inch over 149 sq. mi. approx. = 2,600 mg


117







FLORIDA GEOLOGICAL SURVEY


Peace River basin:
Area: 651 sq. mi.
Runoff 28 inches Rainfall 73 inches
+ Evap. 40 inches Loss 68 inches
Loss 68 inches 5 inches recharge
5 inches over 651 sq. mi. approx. = 57,000 mg

Kissimmee River basin:
Area: 651 sq. mi.
Runoff 20 inches Rainfall 65 inches
+ Evap. 40 inches Loss 60 inches
Loss 60 inches 5 inches recharge
5 inches over 651 sq. mi. approx.= 57,000 mg
1959 Total Recharge is approximately 116,600 mg



These figures indicate that 120 billion gallons of water were
recharged to the artesian limestone aquifers in 1959 over the
Alafia, Peace, and Kissimmee basins. Although these figures are
approximations, they are, however, believed to be of the proper
order of magnitude, and it is evident that the potential recharge
to the artesian aquifers is a relatively few inches of water per
year over the county. As noted in the earlier subsection entitled
"Streams," difficulties in evaluating diversions of streamflow pre-
clude the inclusion of the basins of the Withlacoochee, St. Johns,
and Hillsborough Rivers in these computations. Much of the area
of the Hillsborough River basin in Polk County is an area of
ground-water discharge, hence recharge there is insignificant.
However, such is not the case with the other two, and ground-
water recharge in those areas is a significant, but undetermined
amount, in addition to that described above.
The amount of potential recharge in 1959 represents only a
fraction of the total amount of water actually available for re-
charge. Considerably more water leaves the area by surface
runoff and evapotranspiration than is currently going to recharge.
In addition to these losses, a large quantity of water is presently
being discharged and wasted from the aquifer by artesian springs
(located outside of Polk County) and in areas of artesian flow
within the county. Although there is little that can be done to
reduce evapotranspiration losses, the surface runoff and artesian
discharge is available for use and therefore, constitutes an impor-
tant segment of the water resources of the area. The water pres-
ently being wasted may be used directly from the surface sources


118







REPORT OF INVESTIGATION NO. 44 119

(lakes, streams, springs) or it can be diverted to, or captured by,
the ground-water system.
As future pumpage increases natural discharge from the
aquifers will decrease as a direct response to the lowering of
artesian pressure and piezometric surface. When the piezometric
surface in areas of artesian flow reaches land surface locally, ar-
tesian flow will cease. At that time, water formerly discharged
will have been salvaged for use. One such case occurred in central
Florida when Kissengen Springs, near Bartow, Polk County,
ceased to flow in February 1950. The cessation of flow, and the
causes thereof, have been discussed by Peek (1951). He found that
the rate of consumption of ground water in southwestern Polk
increased rapidly after 1937, and (op. cit., p. 81) that the "na-
tural balance between recharge and discharge was upset, and a
decline of the piezometric surface resulted. The decline of the
piezometric surface, in turn,. caused the discharge of the spring
to decrease progressively until it finally ceased." Although na-
tural discharge from the aquifer can never be stopped, it can be
reduced substantially below the present rate.
Lowering of the piezometric surface in the Floridan aquifer
will in turn increase recharge from the overlying aquifers and
ultimately reduce the amount of water stored in the nonartesian
aquifer. Because of the increased storage available in the non-
artesian aquifer, swamp areas and surface runoff will be de-
creased and in effect captured for recharge to the underlying
aquifers. The tabulation of recharge to the limestone aquifers in
1959, shows that runoff exceeded recharge in the various drainage
basins by amounts ranging upward from a factor of 3. Thus it
is clear that the water available for recharge is vastly more than
that required by the ground-water system to supply present de-
mands.
The water resources of the area are not limited strictly to the
amount of recharge from precipitation on the area. Water pres-
ently being pumped out of the ground is subsequently returned
to the hydrologic system by septic tanks, industrial and sewerage
plant effluents, and irrigation systems. Part of this used water
goes into runoff and evapotranspiration, but a part of it also goes
to recharge the ground-water aquifers and is, therefore, available
for re-use. This is a greatly simplified statement of principles
and conditions, however, great quantities of fresh water are as
yet untapped in Polk County, and probably much of the interior
part of the Florida peninsula.






FLORIDA GEOLOGICAL SURVEY


SECONDARY ARTESIAN AQUIFER
The piezometric map for this aquifer (fig. 22) is not adequate
for defining the recharge areas, and the contours are highly inter-
pretive and generalized. However, the map does indicate four
piezometric highs, or recharge areas, which are partly associated
with the topographic ridges. Some of the lakes in the ridge areas
may be the principal sources of recharge, as water from wells
penetrating the aquifer near these lakes is generally much less
mineralized than water from wells at a greater distance. This in-
vestigation has shown at least one lake in the Lakeland ridge
to be recharging this aquifer in the Lakeland area. Figures 19
and 20 show that Scott Lake overlies a pronounced piezometric
high of the secondary artesian aquifer, and a piezometric trough
of the Floridan aquifer. The water budget for Scott Lake, pre-
sented later in this report, shows that downward leakage occurred
in 1956 at the rate of about 5 inches per month.
The western piezometric high on figure 19, though including
part of the Lakeland ridge in the Scott Lake area, generally
follows the poorly-drained lowland along the western flank of the
ridge in which there are few lakes and sinkholes. The southern
part of this piezometric high underlies Hooker's Prairie, an exten-
sive intermittently marshy area. The piezometric high in the
south-central part of the county includes part of the southern unit
of the Winter Haven ridge, but most of it underlies broad, low,
poorly-drained areas on the flanks of the Winter Haven and Lake
Wales ridges.
The rate of recharge by downward percolation of water
through the confining bed into the aquifer may be determined
from the approximate coefficient of permeability of the confining
bed overlying the aquifer. If the coefficient of permeability of the
confining beds is high enough to transmit the water under the
existing hydraulic gradients in the given period of time, then
recharge will occur. For this purpose the mathematical expression
of Darcy's Law (Q = PIA) may be transposed to P = Q IA.
Recharge to the aquifer is confined almost entirely to the area
of the Peace and Alafia River basins and in which the amount
of recharge was determined to be about 60 billion gallons per
year. Thus Q = 59,600 mg/yr (million gallons). The vertical hy-
draulic gradient, I, is equal to the difference in head (water levels)
of the nonartesian and secondary artesian aquifers, divided by
the distance between the water table and the top of the second-
ary artesian aquifer. Losses of water to the nonartesian aquifer


120





REPORT OF INVESTIGATION NO. 44


and the confining bed may be disregarded in long-term considera-
tions, and other discharge from the nonartesian aquifer has
already been accounted for.
The area of the two basins totals 800 sq. mi. However, several
broad areas along the rivers are areas of flow or upward leakage,
and hence not recharge areas. The area in which recharge may
occur is approximately 640 sq. mi.
Therefore,
59,600 mg/yr 19 ft.
P (gpd/ft.2) = 365 days 65 ft. X 640 sq. mi. X 27.88 X 10" sq. ft/sq. mi.
= 163 X 100g/d 0.293 X 640 sq. mi. X 27.88 X 10" sq. ft./sq. mi
163 X 100g/d
5228 x 10" sq. ft.
= 0.03 gpd/sq. ft.
The permeability of the sandy clay confining beds is substantially
lower than that of the least permeable sand in the Lake Parker
area (Stewart, 1963, table 9) of 20 gpd/sq. ft. The coefficient of
permeability determined here falls within the range of those of
similar materials as listed by Wenzel (1942, p. 13), and which
were determined by laboratory methods.
The coefficient of permeability determined above, though not
precise and representing only a generalized summation of the
thicknesses and permeabilities of the confining beds and cover-
mass over a very large area, is of the proper order of magnitude
for the materials concerned. This coefficient, together with the
known head relationships of the aquifers in most of the area,
and the shape of the piezometric surface, shows that recharge
of the secondary artesian aquifer occurs by downward percolation
of water from the nonartesian aquifer through the confining beds.
Undoubtedly, the coefficient of permeability differs widely
over the area, as do the factors of the vertical hydraulic gradient.
The coefficient determined here, therefore, may not be applicable
for use in small parts of the area and precise computations.

FLORIDAN AQUIFER
The piezometric surface of the Floridan aquifer (fig. 20) is a
large elongate dome which centers about an area in north-central
Polk County. Earlier work (Stringfield, 1935, fig. 3, and 1936,
plate 12) has shown that the piezometric surface under the entire
peninsula is essentially one large dome, with a smaller, lower
dome in Pasco County. His map, slightly revised by later work






FLORIDA GEOLOGICAL SURVEY


and published by Unklesbay (1944, fig. 5), is shown here as
figure 24. Polk County lies across the highest parts of the piezo.
metric surface, and figure 20, therefore, represents only the toI
of the larger feature described by Stringfield.
Like the secondary artesian aquifer, the rocks of the Floridar
aquifer do not crop out in the area of the piezometric high bul
are buried 40 to 150 feet or more below land surface. The small
area of outcrop in northwestern Polk and adjacent counties are in
an area of intermittent artesian leakage. The small amount of re.
charge which may occur in parts of the outcrop area is discharged
into the Withlacoochee River soon after entering the aquifer.
The piezometric high of the Floridan aquifer must, therefore,
also be maintained by the infiltration of rainfall to the water table
and subsequent percolation downward through the nonartesian
aquifer and the underlying confining beds into the limestones
of the Floridan aquifer. In much of the county, the Floridan
aquifer is also overlain by the secondary artesian aquifer, hence,
the recharge indicated by figure 20 must percolate from the non-
artesian aquifer, through the upper confining bed of the second-
ary aquifer, through the secondary artesian aquifer, through the
lower confining bed (common to both aquifers), and into the
Floridan aquifer.
If such recharge does occur, then the coefficient of permeability
of the confining beds must be high enough to permit the passage
of the quantity of water available in the space of time predicted.
For purposes of computation the river basins may again be used
as subdivisions of the county.
In the general area of the Peace and Alafia River basins, the
Floridan aquifer is overlain by the secondary artesian system,
and is separated from it by the mutual confining beds formed by
a bed of blue clay of the Tampa Formation. Recharge to the
secondary artesian aquifer in this area has already been de-
scribed. Recharge to the Floridan aquifer from the secondary
aquifer, through the mutual confining bed, is indicated by the
consistently higher head in the secondary aquifer and by the shape
of the piezometric surface of the Floridan aquifer. The loss of
some of the available water to storage and lateral movement in
the secondary aquifer during transit may be ignored. Some of this
loss has already been accounted for as part of the surface
runoff. On the basis of water going to recharge, Q is equal to
59,600 mg/yr. The area, A, is about 640 sq. mi. The vertical
hydraulic gradient, I, is the average difference in head of the


122








REPORT OF INVESTIGATION NO. 44


27* E- ----.


+"~
(2


- EXPLANATION
Contour lines represent approximately
the height, in feet, to which water would
rise with reference to mean sea level in
tightly cased wells that penetrate the
Floridan aquifer in 1944. (after Unklesbay,
1944, figure 5)
Contour interval 10 feet.

25 0 25 50 75 0
APPROXIMATE SCALE IN MILES


Figure 24. Map of peninsular Florida showing the piezometric surface of
the Floridan aquifer in 1944.


123






FLORIDA GEOLOGICAL SURVEY


two aquifers, divided by the average distance between the tops
of the aquifers.
Therefore,
P (59,600 mg/yr 365 days 18ft (640 27.88 X10) sq. ft. }
90 ft. X 27.88 X1v sq. ft.
163 X 10'gpd
0.20 x (17,800 X ") sq. ft.
163 X 10" gpd
3560 X0l sq. ft.
= 0.04 gpd/sq. ft.
The secondary artesian aquifer is absent in the Withlacoochee
River basin and the St. Johns River basin. Recharge to the
Floridan aquifer is indicated by the low local domes defined by
the 130-foot contours on figure 20, and by the broad area sloping
downward from them. In these basins recharge is occurring under
two widely different sets of conditions. In most of the area (ap-
proximately 320 sq. mi.) head differentials are low, surface drain-
age is poorly developed, and topographic gradients are very low.
The aquifer is confined by sandy clays and clays which are in turn
overlain by sands and clayey sands. These basins also include the
western half of the north end of the Lake Wales ridge, which
is the drainage divide between the Withlacoochee-St. Johns and
the Kissimmee River basins. In much of this part of the ridge
the confining beds of the aquifer are missing or are represented
only by a thin marl or clayey sand, and the Floridan aquifer may
be under nonartesian conditions locally. Surface drainage is es-
sentially nil, the aquifer is overlain by great thicknesses of sand,
and topographic gradients are relatively high. Head differentials
between the water table and the piezometric surface are generally
very low and may be zero in places. Half of the ridge section
is in the Kissimmee basin, and the total area of this part of the
ridge section is approximately 25 sq. mi.
It is recognized that vast differences in permeability, thickness
of the covermass, and lithology exist over the entire area of the
basin.
In the Kissimmee River basin approximately 236 sq. mi. of the
total area is an area of artesian flow or leakage, hence recharge
does not occur. In the remaining 415 sq. mi., however, heac
relationships and the piezometric contours on figure 22 indicate
that recharge is occurring. Of the 57,000 mg available water in
the basin, about 2,000 mg has been shown to occur in 13 sq. mi.


124






REPORT OF INVESTIGATION NO. 44


c.f the northern part of the ridge section. Therefore, about 55,000
Iig is available for recharge to the Floridan aquifer in approxi-
lately 400 aq. mi. of the basin. The average coefficient of perme-
ability then, is
S15 ft
I' = (55,000 mg/yr + 365 days) +- ft. (400 x 27.88 x 101) sq. ft.
= 150 X 106 gpd + (.075 X (11,000 X 101 sq. ft.)}
150 X 10'gpd
830 X 10'sq. ft.
=0.2 gpd/sq. ft.
In this basin there seems to be a wide difference in permeability
of the covermass. The aquifer appears to be overlain by sands,
slightly clayey sands, or thin sandy marls in much of the ridge
portion of the basin, and by more clayey beds in the lowland areas
of the basin. The piezometric surface indicates that much of the
recharge is occurring on the high ridge and sand hills on the
ridge flank.
To summarize, the average coefficients of permeability of the
confining beds and covermass of the limestone artesian aquifers in
the county have been determined on an areal basis as follows:

Secondary artesian aquifer-
Peace and Alafia River basin area 0.03 gpd/sq. ft.
Floridan aquifer-
Peace and Alafia River basin area 0.04 gpd/sq. ft.
Kissimmee River basin area 0.2 gpd/sq. ft.

These permeabilities indicate that recharge to both of the lime-
stone aquifers may occur under existing conditions in the county
by downward percolation of water from the nonartesian aquifer
through the confining beds of the limestone aquifers.
Earlier workers (Sellards, 1908; Matson and Sanford, 1913;
Sellards and Gunter, 1913; Gunter and Ponton, 1931; and String-
field, 1935, 1936), all recognized in differing degrees, the existence
of the buried artesian aquifer and probably recharge area in the
central part of the peninsula. These authors concluded that the
aquifer received recharge by downward percolation of rainfall
in areas where the limestones were near the surface and the
permeability of the over burden high enough. They also concluded
that where overlying formations were thicker and of generally
low permeability downward percolation into the Floridan aquifer


125






FLORIDA GEOLOGICAL SURVEY


would occur through sinkholes, partially filled with sand, which
breached the younger formations. The concept of sinkhole r.-
charge was logical and, in some instances, is quite valid.
The present investigation indicates that (1) some recharge to
the Floridan aquifer does occur through sinkholes, but that this
amount is a relatively small part of the total annual recharge
to the aquifer, (2) recharge occurs over all areas of the county
which are not areas of artesian discharge (fig. 20), and (3) the
amount of recharge through individual sinkholes and lakes does
not necessarily equal or exceed the amount of recharge occurring
in an adjacent nonsink area of comparable size.
The total amount of recharge to the Floridan aquifer in Polk
County has been estimated by drainage basins on preceding pages.
It is estimated that about 25 percent of the recharging area of
the county is comprised of sinkhole or sinkhole lake basins. Pos-
sibly 60 percent of this area, or 15 percent of the county, is
comprised of dry sink basins. The areal distribution of the sinks
and lakes, and the areal distribution of water available for re-
charge are not correlative. The Peace River basin (fig. 2) appears
to contain a large majority of the sinkholes and sinkhole lakes
in the county which could recharge the aquifer. However, the re-
charge estimates show that no more recharge occurs in the
Peace River basin than in the Kissimmee River basin. It, there-
fore, appears that no significantly greater amount of the total
annual recharge is occurring in the principal sinkhole area.
Other data also suggest that widespread areal recharge is oc-
curring within the county. Water in the Floridan aquifer in many
areas is much less mineralized than it is in principal sinkhole
areas or in the area near the top of the piezometric high. Possibly
the outstanding examples are near lakes in the southeastern
part of the county, which is an area of general ground-water
discharge. This is highly suggestive of nearby recharge. Though
other factors may also influence the concentration of chemical
constituents in water, the duration of contact between water
and aquifer is the most significant.
Some recharge to the limestone aquifers occurs from some
of the sinkhole basins and lakes. The dry sinkholes, common i:
the Winter Haven and Lake Wales ridges, are draining water
downward from the surficial sands; otherwise, they would all
contain ponded water. However, the data is as yet inadequate to
establish which aquifer is receiving the leakage. Later section;
of this report will show that Lake Parker, in Lakeland, is re-


126






REPORT OF INVESTIGATION No. 44


c iarging the Floridan aquifer, and that Scott Lake near Lakeland
i. recharging the secondary artesian aquifer, at measurable rates.
Lake Parker is not entirely a sinkhole lake. Some sinkhole lakes
are discharging little, if any, water to the limestone aquifers.
Figure 12 shows the hydrographs for Lake Wire and Hollings-
worth, sinkhole lakes on the ridge in the City of Lakeland. The
water level fluctuations of Lakes Mirror, Morton, Beulah, Hunter
(Stewart, 1963, p. 106-107) are similar to those of Lakes Wire
and Hollingsworth in frequency and magnitude of fluctuation.
Similarly, these four lakes are also sinkhole lakes on the ridge in
Lakeland. The rate of downward leakage from the lakes may be
substantial if the materials filling these sinkhole basins are per-
meable sands. However, all of the lake levels remain relatively
stable, indicating that the recharge to the lakes is enough to bal-
ance any downward leakage. Most of the lakes occupy closed
basins that are relatively small, and range from one to three
times the area of the water surface. The water levels of the lakes
are at different altitudes, and range from 30 to 80 feet above
the piezometric surface of the Floridan aquifer. Topographic
gradients, and therefore water table gradients, within the basins
are low. Recharge to the lakes from the nonartesian aquifer is
small, and downward leakage from the lakes must also be small,
or the lake basins would soon be dry. Many other sinks in the
ridge areas, including large ones such as Lake Ariana in Auburn-
dale and Lake Howard in Winter Haven, appear to have similar
regimens.
If the Floridan aquifer receives a major amount of its re-
charge by the downward percolation of water through the sink-
hole basins and sinkhole lakes, there should be piezometric highs
under and around them. However, figure 20 shows that many of the
sinkhole lakes in the Lakeland ridge overlie piezometric troughs.
It also shows other areas over the county in which ground-water
levels are higher in the inter-lake areas than in wells adjacent
o the lakes. Scott Lake is shown elsewhere in this report to have
originatedd in the Floridan aquifer, but figure 20 shows that it
3 underlain by a deep piezometric trough. Possibly a more out-
tanding example of a piezometric trough underlying sinkholes
s shown by the piezometric surface in the vicinity of the City of
,akeland wells 802-157-10, 11, 12, and 16, in figure 25. This
igure is an enlargement of part of figure 20, and it includes a
lumber of wells which are not shown on figure 20. The City wells
appear to be drilled in a line generally perpendicular to the course


127





FLORIDA GEOLOGICAL SURVEY


Figure 25. Piezometric-contour map of the Floridan aquifer at Lakeland
(November 20, 1959).

of a southeast trending cavern system which passes under Lake
Mirror and Lake Hollingsworth. The water levels shown for the
city wells were made under controlled conditions of pumping
and altitudes were determined by spirit leveling to the nearest
hundredth of a foot.


128






REPORT OF INVESTIGATION No. 44


These data do not exclude the possibility of recharge from the
lakes into the piezometric troughs, but they show that if recharge
is occurring, it is at a rate too low to create a piezometric high.
There is considerable data (table 7) and reliable reported ground-
water levels which indicate that piezometric troughs probably
exist in association with all of the sinkhole basins.
Evidence of major, widespread recharge to the Floridan aqui-
fer through lakes and sinkholes is still lacking. The evidence
showing the likelihood and plausibility of areal recharge by
slow downward percolation of water from the nonartesian aquifer,
through the confining beds, in both sinkhole and inter-sink areas,
is substantial. It is therefore considered that such areal percola-
tion constitutes the most significant method, and contributes
the major amount of recharge to the Floridan aquifer in this
county.

QUALITY OF WATER
CHEMICAL CONSTITUENTS
Rainwater is only slightly mineralized but it gradually dis-
solves some of the soluble minerals as it percolates through the
soil and rocks beneath the earth's surface. Thus, the chemical
quality of ground water depends on the composition of the rocks
through which the water has passed and the length of time the:
water and rocks have been in contact. The quartz sand that con-
stitutes the nonartesian aquifer in Polk County is relatively in-
soluble. Limestone and dolomite, which compose the secondary
artesian and Floridan aquifers, are more soluble common rocks.
The uppermost artesian aquifer, composed largely of quartz sand,
clays, and phosphatic gravels, is less soluble than the limestone,
but is more soluble than the quartz sands.
During this investigation 149 samples of ground water and 10
samples of surface water were analyzed by the U.S. Geological
Survey. A summary of the analyses are presented in table 12.
Individual analyses are presented in the basic data report by.
Stewart (1963, table 8). Analyses of water from Polk County
have also been published by Black and Brown (1951, p. 94-95,
114-115, 117), Collins and Howard (1928, p. 226-227), Wander
and Reitz (1951, p. 9, 11, app.), and others.
Some samples were analyzed for the common chemical con-
stituents, and others were analyzed for only selected constituents.
Results given in table 13 are in ppm (parts per million) unless
otherwise stated.















TABUL 12. Range of concentration of chemical
(Chemical constituents given


constituents in waters of Polk County
in parts per million)


Nunartciuan Upperimost Hecondary Floridan
Hurface water aqu(iifer Artemian aquifer Artexian aquifer aquifer
Constituint From To Froi To From To From To From To
Temperature ('1) 58 83 72 71) 73 74 72 82 71 82
piH ..3 7.7 .1,0 7,0 0.8 7.3 5.8 8.1 0.7 0.1
1sardneol an CaCOI 8 U10 5 .13 215 232 07 30a .11) 28&
Dissolved solidn ,55 220 20 710 21.1 531 I 11 3.13 02 348
Specific conductance 33 381 10.2 921 395 737 17.1 7241 113 500
Silica (8010 2.7 II 8 13 37 1.1 31
Total iron F) .00 ,11 0.4 .51 0,02 0.25 0.01 2.1 0
Calcium (Ca) 1 41 1 57 4 -Ia 18 05 15 107
Magnesium (Mg) 1.2 10 .0 15 -- 25 5. 31 0.0 28
Potassium K) .1 2.7 0 .2 0,0 0.8 0.0 4.0
Bicarbonate (HCOs) 0 218 1 205 252 0 337 32 353
Sulfate (80) 3.2 40 0 22 -- 1.0 0.0 31 0.0 122
Chloride (C) 5.2 10 2.5 20 8.0 0 26 3 32
Fluoride (F .1 1 0.3 0.8 0.0 1. 0
Nitrate (NO) 0.0 1.5 0.2 0,5 0.0 0.9 0.0 4.8
Phosphte (P04) 0.0 .30 0.00 0.80 -- 0. 1 0.00 2. I 0.00 0.3
Number of samples 10 9 2 29 100 (From 71
wells)






REPORT OF INVESTIGATION NO. 44


The pH, or hydrogen-ion concentration, indicates the acidity
or alkalinity of the water sample. Water of a pH greater than
'..0 is alkaline, and of a pH below 7.0 water is acidic. Water from
imestone aquifers normally has a pH greater than 7.0, but table
12 shows that the lower range of pH for water from the secondary
and Floridan aquifer is less than 7.0. One water sample from
each of these aquifers and one sample from one multi-aquifer well
had values of pH below 7.0.
The hardness of a water is caused chiefly by the ions of cal-
cium (Ca) and magnesium (Mg). These constituents are dis-
solved from the limestone (CaCOs) and dolomite (CaMg(C03) 2)
that compose the secondary artesian and Floridan aquifers.
Water with total hardness of more than 121 ppm is considered
to be hard, and is commonly softened for household and certain
other uses. The hardness of water from the secondary artesian
aquifer in Polk County ranges from 67 to more than 306 ppm,
and that in the Floridan aquifer from 40 to 284 ppm. Water from
wells open to both the secondary artesian and the uppermost
artesian aquifers have hardness values as high as 306 ppm. Two
samples of water from the uppermost artesian aquifer had a
hardness of 215 and 232 ppm. The hardness of water from the
nonartesian aquifer is usually less than 100 ppm, but was much
higher in the analyses of samples from wells 802-156-1 and 806-
149-5 (202 and 430 ppm). Water in the nonartesian aquifer is
greatly affected by local land use. For example, well 802-156-1
is located in the yard of a transit-mix-concrete plant, and is in-
fluenced by rainfall leaching cement, and percolation into the
ground-water body; well 806-149-5 is located in a heavily ferti-
lized citrus grove.
Figure 26 is a map showing the hardness of water from the
Floridan aquifer. A comparison of figures 26 and 20 does not
show a clear relationship between mineralization (hardness) and
either distance from the top of the piezometric high or the hy-
draulic gradient between the wells and the piezometric high. The
low hardness of water in areas distant from the top of the piezo-
metric high probably indicates that water is also entering the
aquifer (recharging) down gradient.
Hydrogen sulfide (H2S) is a gas which is held in solution in
ground water. Upon exposure to air some of the gas escapes and
imparts its characteristic odor of rotten eggs. The objectional
odor can be easily removed from the water by aeration. Locally,
water from the secondary artesian aquifer contains this gas in


131






FLORIDA GEOLOGICAL SURVEY


.1640 922

1 160 \ "


I ISO





L


EXPLANATION
125
Well
I Number is total hardness
)3 \ (as CaCO3) water in ports
S 126 per million
S--100--
O Line of total hardness,
-:3 n \ Contour interval 50 ppm
*Hainos City
,,y


*Ft Meads
166


0 10 miles


Figure 26. Map showing hardness of water in selected wells in the Flori-
dan aquifer.


small quantities. Water from many wells deep into the Floridan
aquifer contains noticeable amounts of this gas. However, water
from the wells in the upper part of the Floridan aquifer generally
does not contain the gas.
Iron (Fe) differs from most other chemical constituents nor-
mally found in ground water, in that concentrations of only a few
tenths of a part per million causes the water to have a disagree-
able taste and stains fixtures, laundry, the outside of buildings,
and even grass and shrubbery if it is used in a sprinkler-type
irrigation system. The iron remains in solution until it is ex-
posed to air, where it contacts oxygen and precipitates as an
oxide. The occurrence of water having a high concentration of
iron is unpredictable and may differ with depth, as well as loca-
tion within the county. A well that produced iron-free water


132






REPORT OF INVESTIGATION NO. 44


wvhen first drilled may, with time and pumping, intercept water
of high iron content from nearby areas.
Iron can be removed from water by aeration and filtration,
or by use of chemical filtration or ion-exchange systems. Aera-
tion exposes the water to the oxygen in the air and most of the
iron is precipitated. The water is then passed through a filter,
usually sand or charcoal, where the precipitate is removed.
CHANGE OF CHEMICAL QUALITY WITH TIME
During the investigation four wells were sampled twice for
chemical analysis (753-150-1, 804-154-8, 809-153-3, and 815-
157-2). In a period of about 4 years (1955-1959) water from
well 753-150-1, at Bartow, decreased about 50 percent in minerali-
zation, and water from well 815-157-2, near Rock Ridge, de-
creased about 15 percent. During the same approximate period
mineral content in water from well 809-153-3 decreased about
5 percent. Conversely, in 11/2 years (1955-56) the mineral content
increased fivefold in water from well 804-154-4, on the east
shore of Lake Parker in Lakeland.
The change in chemical character of the water in an aquifer
is related to many factors in addition to the chemical composition
of the aquifer itself. Among the more important of these are
length of time that the aquifer and water are in contact, the
amount and rate of recharge, amount and rate of discharge, hy-
draulic gradient, and permeability of the aquifer.

CHANGE IN CHEMICAL QUALITY WITH DEPTH
Water samples were collected during the drilling of seven wells
in the county to determine changes in the chemical quality of
water from one formation to another and with increasing depth.
Additional samples were collected from several different depths
in five existing wells. The analyses of samples from 12 wells are
included in the basic data report (Stewart, 1963, table 8).
The results of the analyses show no significant changes in
concentrations with depth in five wells. They show a marked
increase in mineralization with depth in one set of drilling sam-
ples, and very slight increase in three sets of drilling samples.
A marked decrease occurred in one set of drilling samples and
one set of bailed samples. It may be noted that the data do not
show a single ion or physical characteristic of water in the
Floridan aquifer which changes consistently with depth or geo-
logic formation.


133






FLORIDA GEOLOGICAL SURVEY


WATER TEMPERATURE
Collins (1925, p. 101) found that the temperature of ground
water is generally from 20 to 3F above the mean annual air
temperature if the water is between 30 and 60 feet below the
surface of the ground, and that the approximate average increase
in temperature with depth is about 1F for each 64 feet.
The average annual temperature in Polk County ranges from
72.30F to 72.7F (4 stations). On the basis of Collins' work, the
water temperature of the secondary artesian aquifer would be
expected to average about 74.5F, and that of the Floridan aqui-
fer about 84-900F. The measured temperatures of water ranged
from 72F to 820F in the secondary artesian aquifer and from
71F to 82F in the Floridan aquifer. In the nonartesian aquifer
temperatures ranged from 72F to 790F, and from 73F to
74F in the uppermost artesian aquifer. Figure 27 is a map


Figure 27. Map showing water temperatures in selected wells in the Flori-
dan aquifer.


134






REPORT OF INVESTIGATION NO. 44


showing the temperature of water in the Floridan aquifer as
determined during water-sampling programs. The water tempera-
tures shown on figure 27 are the temperatures measured at the
pump discharge, and, therefore, are the composite temperatures
of all the water reaching the individual wells.
Temperature logs were made for 12 wells in the county under
static conditions, using a thermistor-type logger, and are presented
in the basic data report (Stewart, 1963, fig. 3). In many wells
having water levels within 20 feet of land surface the tempera-
ture of the water increased slightly to a depth of 40 to 60 feet.
Below these depths the temperature either remained constant
within several tenths of a degree or decreased slightly.
In eight wells having 200 to 440 feet of open hole, the tempera-
tures increased overall from the bottom of the casing to a depth
of 500 feet, in amounts ranging from 0.1F to 0.90F. On the
basis of these net changes the average increase with depth ranged
from 0.04F to 0.37F per 100 feet. The amount of open hole
or location of well do not seem to correlate in any way with net
change in temperature, or average rate of change.
In four wells with 30 to 110 feet of open hole, net changes in
temperature in the open hole ranged from +10F to -0.90F. These
wells were less than 350 feet total depth. Two of them were open
only to the secondary artesian aquifer.
In well 818-151-2 the temperature decreased 1.40F from the
bottom of the casing at -63 feet to the total depth of 150 feet.
This is believed to be due to effective and rapid recharge to the
Floridan aquifer from the nonartesian aquifer. A slight decrease,
and subsequent slight increase, was noted in wells 804-151-6,
801-156-1, and 754-151-4. This may indicate slow recharge to the
aquifer where it is more deeply buried. In the case of 801-156-1,
it may represent leakage (recharge) to the aquifer from nearby
Lake Hollingsworth as well.
It is interesting to note that the maximum temperature in
these explorations at depth of 500 feet below land surface was
79.7F in well 753-158-3. However, the maximum temperature
usually did not exceed 750F.

SUMMARY OF CHEMICAL QUALITY
The concentration of dissolved minerals in the water of the
aquifers of this county differs considerably within each aquifer,
and the ranges of concentration in a given aquifer overlap those
of other aquifers.


135






- FLORIDA GEOLOGICAL SURVEY


The temperature of water in the open-hole portion of wells
shows little change to depths of 500 feet below land surface and
seldom exceeded 750F. Samples obtained by pumping, however,
ranged up to 810F.
The chemical quality of water from the-limestone aquifers may
change considerably within a few years because of location and
rate of recharge and permeability of the aquifer. Changes in
chemical quality of water with depth are inconsistent in the wells
sampled, although samples from about half of these wells indicate
no appreciable change to depths of about 500 feet.


WATER USE
Nearly all water supplies in Polk County are withdrawn from
ground-water aquifers. The majority of these are furnished by
wells open only to the Floridan aquifer. This is especially true of
wells which are 12 inches or more in diameter, and is generally
true of 8- and 10-inch wells. Smaller diameter (2- to 6-inch) wells
may be open to either or both the secondary artesian or the
Floridan aquifers. The uppermost artesian aquifer is seldom used
because of high mineralization, clay content, and pollution. The
nonartesian aquifer supplies a few small domestic wells and locally
furnishes small irrigation supplies.
Wells were classified as to the principal use of the water pro-
duced in compiling and estimating the 1959 water consumption
in the county.

PUBLIC SUPPLY
Public supplies are all city and town supply wells and wells
that supply recognized housing developments and subdivisions.
Pumpage is not metered by many of the public water systems in
the county. Table 13 shows the metered pumpage data available
for the period of this investigation. Lakeland, Highland City,
Polk City, and the small communities of Sand Gully and Tancrede

TABLE 13. Annual metered pumpage by municipal systems in Polk County,
1954-59 (millions of gallons)

City 1954 1955 1956 1957 1958 1959
Haines City 282.19 334.93 351.69 329.26 358.85 -
Highland Park 24.90 24.34 27.47 22.92 21.66 22.11
Lakeland 2.133.94 2,170.03 2,412.09 2,268.34 2.651.42 2.561.58
Lake Wales 373.86 428.10 484.87 439.84 464,89 -
Winter Haven 931.37 1,022.64 922.26 975.77


136







REPORT OF INVESTIGATION NO. 44


(Standard Village) near Lakeland, each have separate public water-
supply systems, but all of these systems are operated and main-
tained by the City of Lakeland. There are 13 wells in the Lake-
land city system, 2 wells in Highland City, and 1 each in the other
communities. Total pumpage records are available from the Lake-
land city system beginning with 1928. The total annual pumpage
of the Lakeland system is shown in figure 28. Pumpage at the
other four communities is not metered and is not included.

2.800

2,600- ---------7

2,400


2p00---- ---------------------- ---- |
2.200



Z I,4Z/
zi.800 -_-- ___ __ _




S100 _________________________z_


S___________________ /
,Boc- ~ ^ ^ ^ ^ ^ ^ ^
60C___ [722 2 2 22 2 2


928 1930


1935 1940 1945 1950 1955 1959


Figure 28. Graph showing total annual municipal pumpage by City of
Lakeland, 1928-59.

Estimates of the total pumpage by other municipal systems
in the county were based on data compiled by the Florida State
Board of Health in 1959. These data were revised to bring them
into agreement with 1960 census data and the pumpage data
of table 13. A total of 85 municipal supply wells inventoried
during the investigation are believed to be 95 percent of all such
wells in the county. All of the water supply systems of the charted
towns and cities are publically owned. A few smaller communities
such as Gibsonia, near Lakeland, and those of most of the subur-
ban developments and subdivisions are privately owned and op-


137






FLORIDA GEOLOGICAL SURVEY


rated. The category of Public Supply does not include very
small private systems used to supply only 3 or 4 homes.
Also included in the general category of Public Supply are
wells which furnish water to the public at large. Wells in this
category are those supplying motels, restaurants, and public parks.
The estimated pumpage from these wells is based on a total of
59 wells inventoried. These are assumed to represent about 50
percent of such wells in the county.
The total annual pumpage for public supply in 1959 are esti-
mated as follows:
Municipal supplies .--------------- 7,100 mg
Other public supplies ----_-_------- 62 mg
Total --..-_----- 7,162 mg

DOMESTIC SUPPLY
This classification includes individual wells which supply gen-
eral household requirements, urban or rural. It does not include
wells used only for specific non-household purposes, such as lawn
irrigation, air conditioning, swimming pools, and others. The es-
timated pumpage is based on the 1960 census, Florida State Board
of Health data, and an estimated daily per capital usage of 60
gallons. Approximately 270 wells in this category were inventoried,
and these are believed to be much less than 25 percent of all
such wells in the county.
Total annual pumpage by domestic wells in the county in
1959 is estimated at 1,200 million gallons.

INDUSTRIAL SUPPLY
This category of wells includes those used for purely industrial
purposes, and those used, all or in part, by various industries for
housekeeping, air conditioning, and the like.
Most industrial supplies are obtained from the Floridan aqui-
fer. However, the phosphate mining industry obtains considerable
amounts of water from seepage into the mine pits. These pits
cut through the nonartesian and uppermost artesian aquifers, and
some cut into the secondary artesian aquifer. The pumpage for the
phosphate industry given below includes pumpage by all mining
processing, refining, and associated fertilizer plants in the county.
A total of 65 wells were inventoried in this category and these
are believed to be 100 percent of those in use now, or in the
past 3 years. Many older and abandoned wells of this industry


138






REPORT OF INVESTIGATION NO. 44


were also inventoried. The estimate pumpage is based on pumping
rates and durations furnished by the various phosphate com-
panies.
The pumpage by the citrus industry includes only the packing
and processing phases of the industry-not the irrigation of
citrus which is included under Irrigation Supply. The total pump-
age is based on average pumping rates and durations supplied
by most of the companies concerned, and estimates for the other
companies based on the furnished data. The 50 wells inventoried
in this category are believed' to represent about 95 percent of the
active wells in the county. A number of citrus-packing companies
(fresh fruit) utilize municipal supplies, their requirements being
relatively small compared to the canning and concentrate plants.
Ice and laundry plants are relatively large water users, but
are few in number. The pumpage estimates are based on rate
and duration data furnished by ice companies, and on metered
pumpage data furnished by two laundries in Lakeland.
Miscellaneous industrial wells include all other industrial sup-
plies not specifically mentioned above. For the most part, these
are small systems supplying boilers, air conditioning, and fire,
irrigation, and housekeeping requirements, rather than direct
process use. The 35 wells inventoried in this category are believed
to represent about 50 percent of the total number in the county.
Total industrial pumpage in 1959 is estimated as follows:

Phosphate industry
Wells .._..----------------------------- 38,000 mg
Pit pumpage --_-------------------- ----- 13,000 mg
Citrus industry
Wells for processing -- ---------- 10,000 mg
Laundries (using own wells) --------- 23 mg
Ice manufacture (own wells) ------------- 540 mg
Miscellaneous industrial use -- -------- 630 mg
Total ----- -- 62,193 mg

IRRIGATION SUPPLY
The abundant rainfall not withstanding, irrigation is normally
required about once per season for the citrus crops of the county.
Such irrigation is vastly greater than all other irrigation uses in
the county combined because of the acreage involved and high
evaporation rates. The irrigation of truck crops is more frequent,


139






FLORIDA GEOLOGICAL SURVEY


but of shorter duration and lower rates, because of multicrop
yields from single fields in each year.
Both ground and surface water are used for irrigation, but the
largest quantity comes from ground-water sources. Most irriga-
tion wells obtain water from the Floridan aquifer, secondary
aquifer, or both. A few farm irrigation systems use water from
wells in the nonartesian aquifer, and a very few use water pumped
from shallow artificial ponds in the nonartesian aquifer. The
principal use of surface water is for the irrigation of citrus groves,
and lakes are widely used except in the Lakeland ridge area.
The estimated pumpage from wells, listed below, is based on
339 inventoried citrus irrigation wells which are believed to rep-
resent about 40 percent of the total such wells in the county, and
144 other irrigation wells believed to be 75 percent of non-citrus
irrigation wells in the county.
The estimated irrigation pumpage in 1959 is as follows:
Citrus crops
Wells -...---------------- 8,600 mg
Lakes----- .....-------------... 1,400 mg
Farm crops
Wells -- ------------ 10 mg
Ponds & Lakes
Total irrigation use 8,610 mg (ground water)
1,400 mg (surface water)
Pumpage from lakes for citrus irrigation is estimated from the
number of installations observed, average capacity of the pumps
used, and average length of irrigation period. The amount of
water pumped from ponds and lakes for farm crop irrigation is a
relatively insignificant amount.
MISCELLANEOUS SUPPLIES
Several other ground-water uses do not fit into the preceding
general categories of wells. They represent a relatively small part
of the total county pumpage, but are none the less a part of the
total. The following estimates of annual pumpage are based on
50 inventoried wells which may represent less than 30 percent of
the total number of such wells in the county.
Livestock and dairies --- ----------- 80 mg
Air conditioning and swimming pools only _10 mg
Railroads, for housekeeping use only -
Total ------- 90 mg


140






REPORT OF INVESTIGATION NO. 44


SUMMARY OF WATER USE
The total estimated annual ground-water pumpage in Polk
County in 1959 was 79,255 mg. Another estimated 1,400 mg is
pumped from surface-water sources each year. The ground-water
pumpage reduces to an average rate of about 217 mg per day, or
151,000 gpm, each minute of the year. The total annual pumpage
represents the amount of water which would cover the entire
county to a depth of approximately 21/ inches.
Total annual pumpage will vary considerably from year to
year because of the amount and distribution of rainfall, particu-
larly with reference to citrus irrigation and municipal require-
ments. However, because more citrus acreage is being planted
and more citrus produced, and growth in industry generally, the
pumpage for industrial use can be expected to increase in the
future. Continued population growth and increased municipal
and domestic pumpage can also be anticipated. Note that the
City of Lakeland pumped more in the wettest, year of record
(1959) than in one of the driest years of record (1956), only 3
years earlier (figs. 3 and 28). Contributing to this increase, in
addition to population growth, is a changing way and standard
of living which utilizes more water-consuming facilities-auto-
matic dishwashers, clothes washers, shower baths, swimming
pools, air conditioning, lawn irrigation systems, and many others.

SPECIAL PROBLEMS
LAKE PARKER
HISTORY AND NATURE OF THE PROBLEM
A local problem of considerable importance concerns the future
of Lake Parker in eastern Lakeland (fig. 13). The possibility that
the water level in this lake might be greatly lowered by future
large withdrawals of ground water in and near the northern and
eastern shores is a matter of great concern to the residents of
Lakeland, to the city government, and to industry.
Lake Parker covers about 2,200 acres and is generally very
shallow. Soundings made in May 1954 indicated that at the
deepest point the lake was approximately 9 feet. At that point the
lake bottom is approximately 119 feet above msl.
The northern part of the lake's drainage basin is low and
relatively flat. On the east and south sides of the lake the drainage
divide is relatively close to the shore. In the southwestern part






FLORIDA GEOLOGICAL SURVEY


of the basin there is a steep gradient from the ridge in central
and northern Lakeland. Northwest of the lake the basin widens
appreciably.
Small streams enter Lake Parker from a large sinkhole basin
west of the lake in northern Lakeland, and from Lake Gibson and
other sources northwest of Lake Parker. Several small canals
enter the northeast arm of the lake from surrounding swampy
areas. The lake overflows through a canal extending from the east
shore into the Saddle Creek drainage system. A concrete control
structure in the canal, near the lake, prevents outflow when the
lake level is lower than 129.6 feet above msl.
The City of Lakeland operates a powerplant on the south
shore of Lake Parker, at the site of well 802-155-1. This plant,
which produces 70,000 kilowatts, uses water mostly from Lake
Parker for cooling the power units. The plant when in full opera-
tion uses lake water at a rate in excess of 108,000 gpm." This
usage is more than 10 times the measured yield from any well
in the county and more than twice the average pumpage rate
for the city system in 1959. The water withdrawn from the
lake, plus a small amount used from the nearby city supply
well, returns to the lake after passing through the powerplant.
In order for the intake system of the plant to operate, the lake
level must be more than 125.45 feet above msl.
Some data concerning the subsurface geology in the Lake
Parker area were obtained from the prospecting records of the
American Cyanamid Co. and some were obtained by drilling test
holes. A composite geologic section made from these data follows:
Thickness
Material (feet)
Sand, quartz, gray to dark-brown 2-20
Sand, clayey, tan to brown 5-10
Clay, sandy, phosphatic, yellow to gray-green 5-10
Clay, sandy, yellow to brown; phosphate pebbles 3-10
Clay, sandy, brown; limestone fragments 1-4
Limestone, sandy, phosphatic
This general sequence of sediments is found throughout the low-
land area around Lake Parker.
Occasionally, in prospecting for phosphate, so-called "blank
holes" are encountered. In the Saddle Creek-Lake Parker area, the
SPersonal communication from Mr. C. D. Macintosh, Jr., Superintendent,
Light and Water Dept., Lakeland, Nov. 8, 1960.


142






REPORT OF INVESTIGATION NO. 44


term "blank holes" refers to test borings in which only traces of
phosphate were found or in which no phosphate was found. Usu-
ally, sand is the only material penetrated. Prospect borings gener-
ally terminate just below the base of the phosphate-bearing
clays, and just above the limestone of the Hawthorn Formation.
"Blank holes" generally terminate at depths well below the level
of phosphate deposits found in nearby test holes.
In some places the mapped locations of the "blank holes"
appear to follow a pattern much like a stream course. One such
pattern was noted in the area in and around the northern arms
of Lake Parker by personnel of the American Cyanamid Co.
during the company's prospecting operations. If the thick sand
sections in these patterns continue downward to the underlying
limestone, they would permit much greater local leakage, or re-
charge, from the lake to the aquifer than would occur through
the clay confining beds normally found throughout northwestern
Polk County. Test hole 805-156-A (fig. 13) was drilled in the
bottom of Lake Parker near the mouth of the northwest arm of
the lake, in one of the deepest sand sections of the pattern, to
determine if the sand extended downward to the limestone bed-
rock. Figure 29 shows the materials which were penetrated. The
data from the test drilling indicates that the normal sand and clay
sequence, found in hundreds of logs of phosphate prospecting
holes in the area, probably continues under the lake. The surficial
sands are not known to extend to the limestone in the area ad-
jacent to Lake Parker. However, this does not preclude the
absence of clays from very small areas because prospecting holes
are generally drilled 100 yards apart.
From 1949 to July 1954, the lake level was measured by the
engineers of the city light plant at a staff gage on the pier at the
plant. A continuous water-level recorder was installed on Lake
Parker on July 21, 1954. Figure 30 shows the hydrographs of
Lake Parker, well 803-154-10 in the secondary artesian aquifer
(fig. 17), and well 806-154-1 a multi-aquifer well (fig. 21). There
is a general correlation of water-level fluctuations in the three
hydrographs. Departures of the hydrograph of well 803-154-10
from the pattern of the other hydrographs was probably due to
varying pumping rates in active mine pits south of point E,
fig. 17. Figures 31 and 32 show the hydrographs of Lake Parker,
and nearby wells in the nonartesian, the secondary, and the
Floridan aquifer. These wells were drilled for the U.S. Geological
Survey and are located on the south side of the northeast arm


143











O -
0-








10-








20-



0
O


30
O














6J
4 60-








S50-



t-












L-


80-


90



r
rr.
r-
r
r r




~ ,







r

~
r

r
r
r
,

r

~ I
11




r


r



~


r
r
r
r



r
'r
r .
,
r


r
r


I


,~~


r
r
r
-
.
_r
r
r
r

r
r rr
r-.
.r

.~4
~~I






r




SBottom elev.= 35msl


Muck, block, soupy

Sand,dork-brown; much fine

organic debris.




Sand, light-tan; slight amount
of organic moteriol; becomes
lighter colored downward.








Sond, chocolate-brown; sharp
contact with lighter colored
sand above; much fine

organic material; becomes

very slightly clayey in

lower 5 feet.





Peat, black, porous; very little
sand or clay.








Sand, chocolate-brown, slightly
clayey; amount of organic
matter increases below

58 feet.










Sand, brown, lighter than above;

much organic matter; becomes
slightly to moderately clayey

below 74 feet.

Cloy, gray-green, very sandy, tough,
dense; becomes waxy and has
little sand below 85 feet.

Cloy, yellow-brown,dry, tough, greasy.

Clay, greenish-gray, sandy, gritty, contains
tough dense yellow streaks.

Clay, as above; contains weathered lime-
stone fragments.


Figure 29. Log of sediments penetrated in test hole 805-156-A, in Lake

Parker.

144


1

















12 7 1 1 i 1 I I I I I I I I I I I 1 1
127 128&1 11 1 I I I 1 1 1 1
127

126

S125

W 124

z
< 123
w
122
w
o 121

i- 120-Well 803-154-10
" 3.2 miles northeast
L Of Lakelahd. (Secondary ortesion aquifer)
119 -.. .
z Depth of well 69 ft.
,- I18 Depth of casing 39 ft.



cr 125
J I I I I I I I I I I I I I I I I I
11--- ^ ----- -
A II


Figure 30. Hydrograplh of water levels in Lake Parker, and in wells 803-
154-10 and 806-154-1, 1954-56.
145







146


FLORIDA GEOLOGICAL SURVEY


* 125

124




Well 805-155-3, eor Lakelond (Secondary artesian
aquifer)
121



119





S16
S. ell 805-155-2, near Lokelond (Floridan aquifer)


114

113 ------y j - - - -

112
1955 1956 1957 1958 1959

Figure 31. Hydrographs of water levels in Lake Parker and in wells 805-
155-1, 2, and 3, 1956-59.







REPORT OF INVESTIGATION No. 44


i 122 --_ __ Well 805-155-3,a1 Lakeland (Secondary oaresion aquifer)
S12 -- -






1165 7 ... . .. ..
r-vx- VV -


Well 805-155-2, at Lokelond (Floridon aquifer)

115-----
114 ---
JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC
1958
Figure 32. Hydrographs of water levels in Lake Parker and in wells 805-
155-1, 2, and 3 during 1958.

of Lake Parker. Well 805-155-2 is 40 feet east of 805-155-1;
805-155-3 is 130 feet east of 805-155-2. The wells were equipped
with continuous water-level recorders, and there is a similarity
of fluctuations of lake and ground-water levels.

WATER BUDGET
In order to evaluate the relation of Lake Parker to the adja-
cent and underlying aquifers, a water budget was compiled that
estimates the amounts of water entering and leaving the lake
during the period January 1 to June 20, 1956.
Rainfall on the lake, assumed to be the same as that measured
at the Lakeland station, contributed approximately 17 inches of
water to the 2,200 acres of lake surface during the period of study.
In order to determine the general relationship and magnitude
of surface-water inflow to and outflow from Lake Parker, the


147






FLORIDA GEOLOGICAL SURVEY


discharge of all streams flowing into or out of the lake was meas-
ured once in September 1955 and again in February 1956 by the
Surface Water Branch, U.S. Geological Survey, Ocala, Florida.
Figure 13 shows the location of all gaging points, and table 14

TABLE 14. Stream-flow measurements in the vicinity of
Lake Parker and Saddle Creek
(Measurements by U.S. Geological Survey, Ocala, Fla.)

Station shown Flow (cfs) Flow (cfs)
on figure 16 9-15-55 2-15-50
Iake Parker:
K (Inflow) 1.67 1.00
L (Inflow) .54 .22
M (Inflow) 4.63 .28
N (Outflow) 3.38 .00
Saddle Creek:
A 9.96 14.00
B 45.20 8.22
C 15.30 3.00
J 116.00 14.00


lists the two sets of measurements made at these points. In
September 1955 the lake was above the level of the outlet-control
structure, total surface inflow was 6.84 cfs (cubic feet per sec-
ond), and total outflow was 3.38 cfs. In February 1956, when the
lake was below the level of the outlet-control, total surface inflow
was 1.50 cfs and there was no surface outflow. Surface inflow prob-
ably exceeds surface outflow during most or all of the year. The
inflow to the lake during the test period was estimated to be
8.1 inches over the lake surface; the outflow during the same
period was estimated to be 3.3 inches.
City storm sewers carry the drainage from approximately
1.7 square miles (1,100 acres) into Lake Parker, but probably not
more than 25 percent of the total rainfall on this area reaches
Lake Parker through the sewers. Thus, 1,100 acres X 17 inches
X .25 2,200 acres = 2.1 inches of water contributed to Lake
Parker from storm sewers.
Lake Parker receives some overflow water from Lake Mirror
through gravity-flow drains. Lake Mirror, in turn, receives over-
flow from Lake Wire. The amount of water added to Lake
Parker from this source is unknown.
Ground-water inflow to Lake Parker from the nonartesian
aquifer can be computed by the use of Darcy's law, which can
be written as Q = PIA, where Q is the flow in gallons per day;
P is the coefficient of permeability; I is the hydraulic gradient in


148







REPORT OF INVESTIGATION NO. 44


feet per foot; and A is the area in square feet of the cross section
through which the flow is taking place. The average permeability
of the sands sampled in the lake bottom (Stewart, 1963, table 9),
85 gpd per sq. ft., was used in making these computations. Hy-
draulic gradients were determined from figure 13, a map of the
water table in the Lake Parker area. Saturated thicknesses of
the nonartesian aquifer were taken from drilling and test data.
The total ground-water inflow to Lake Parker was thus com-
puted to be 220,000 gpd. This amounts to approximately 0.7 inch
of water over the lake surface from January through June 1956.
The evaporation loss from the lake between January 1 and
June 20, 1956, was estimated to be 23 inches.
The approximate water budget may then be tabulated as follows:

Gains: Inches of water
Rainfall 17.0
Surface inflow 8.1
Storm-sewer inflow 2.1
Ground-water inflow .7
Lake Mirror overflow ?
27.9+
Losses:
Evaporation 23.0
Surface-water outflow 3.3
Ground-water outflow in nonartesian aquifer 0.0
26.3
Difference (downward flow to aquifers) 1.6

The amount of the difference between gains and losses is well
within the accuracy limits of some of the data used in computing
it, and therefore has little significance. The budget appears to be
essentially in balance. However, during this period, the lake
actually declined about 14.5 inches (fig. 30). Other factors in the
budget having been accounted for, this decline is due primarily
to vertical seepage from Lake Parker into one or more of the
underlying artesian aquifers. Figures 17 and 21 indicate that this
leakage is probably going into the Floridan aquifer rather than
into the secondary artesian aquifer. This is shown by the bulge in
the piezometric surface of the Floridan aquifer under the lake
(fig. 21), and a trough in the piezometric surface under the lake


149






FLORIDA GEOLOGICAL SURVEY


is indicated for the secondary aquifer (fig. 17). Such a relation-
ship may be due to generally more permeable materials filling
the erosional channels in the lake bottom, where the secondary
aquifer is absent, than in the less disturbed or reworked mate-
rials overlying the secondary aquifer in the shore areas. It may
be due in part to the greater hydraulic gradient existing in
the filled channel sections than in the shore areas.
The coefficient of permeability used in this budget is applicable
to the sands of the nonartesian aquifer only. However, the sand
in the lake bottom is known to be underlain, at least in part,
by clays and sandy clays which observation indicates are probably
of much lower permeability than the sands. The coefficient of
vertical permeability of the materials overlying the Floridan aqui-
fer in the lake bottom may be approximated by transposition
of the formula Q = PIA, to P = Q/IA. From the water budget
above, Q = 2.5 inches/month = 0.051 gpd/ sq. ft. From figure 29,
and the piezometric map of the Floridan aquifer in 1956 (fig. 21),
the vertical hydraulic gradient, I, equals the difference in head of
the lake and the aquifer divided by the distance between the
lake bottom and the top of the aquifer, or I = 2/oo ft. The
area through which the flow is taking place is 1 sq. ft. There-
fore-

P = .051 gpd/sq. ft. + (23 ft. 100 ft.) X 1 sq. ft.
= .051 gpd/sq. ft. + 0.23
= 0.22 gpd/sq. ft.

The coefficient derived here represents a summation of the
thickness and permeabilities of all the materials which overlie
the limestone aquifers in the lake bottom. Though it is recognized
that leakage through the lake bottom may, or may not, be oc-
curring in only a small part of the lake, the coefficient derived
here is useful in that it provides some knowledge of the order of
magnitude of the permeabilities of the confining beds of the aqui-
fer and the lake bottom sediments. Other factors in the budget
having been accounted for, the observed decline of the lake is due
primarily to vertical seepage from the lake to the underlying
Floridan aquifer. At other times, the lake receives more water
than it is losing and as a result lake level rises. The fluctuations
of the lake level, both long and short-term are the result of im-
balance between gains and losses of water.
It is not known whether recharge to the artesian aquifer from


150






REPORT OF INVESTIGATION NO. 44


Lake Parker occurs over most of the lake bottom or in only certain
areas. Chemical analysis of ground-water samples, however, shows
that the mineral content of the water from both the Floridan
and the secondary artesian aquifers is lowest near the north-
eastern arm of Lake Parker and Fish Lake, suggesting that the
best connection between Lake Parker and the artesian aquifers
is in that area. This is also supported by the hydrographs of
figure 32, showing rapid response to recharge and discharge by
all aquifers.
The contours on figure 17 indicate that water may have been
leaking from Lake Parker into the secondary artesian aquifer in
June 1956 and moving laterally through the aquifer to discharge
at spring E, near Saddle Creek. In December 1954, water was
pumped at a rate of 7,500 gpm from an active mine pit in the
secondary artesian aquifer, 0.3 mile south of spring E (fig. 17).
Such withdrawals were made in the general vicinity of springs E,
F, and G from late in 1953 until late in 1957. These prolonged
withdrawals do not appear to have affected the level of Lake
Parker substantially. If any such leakage into the secondary ar-
tesian aquifer occurred, it was a very small amount. The observed
decline of the lake level during 1954-1956 is largely due to below
normal rainfall, continued downward leakage, reduced inflow, and
increased evaporation. The decline of Lake Parker is consistent
with, but less than, the decline of other lakes in the vicinity that
are farther from the mining area.

CONCLUSIONS
The future withdrawal of ground water from mine pits in the
nonartesian aquifer in the area south of State Highway 33 and
north and northeast of Lake Parker may tend to lower the level
of the lake in these ways: (1) It will reduce the ground-water
inflow into the lake by interception, and (2) it might induce
ground-water outflow from the lake through the nonartesian aqui-
fer toward areas where the water table is drawn down to especi-
ally low levels near the shore. (3) Withdrawal of water for
mining from the artesian aquifers also will lower the piezometric
surface and increase the vertical hydraulic gradient under the lake,
thus increasing the rate of leakage from the lake to the aquifer.
If mining takes place in the lake itself, severe lowering of the
lake level by increased downward leakage could occur. Without
consideration of possible remedial measures, the leakage could


151






FLORIDA GEOLOGICAL SURVEY


be increased in the following ways, in addition to the three ways
listed above:
(1) Such mining would probably proceed by segmenting the
areas to be mined by construction of earth dams and then pumping
the segments dry. Such pumping and subsequent removal of the
lake bottom sands and underlying leached zone and matrix would
create a substantial hydraulic gradient on opposite sides of the
dams. This would induce leakage from the lake by underflow
through the permeable sand bottom under the dam and into the
pit. (See fig. 29.) Under existing conditions this could be sev-
eral millions of gallons per day in a pit 1,000 feet long and an
average sand thickness of 20 feet. Given sufficient flow in this
situation, it is possible that the sand would erode rapidly from
under the dam into the pit. Such an occurrence would permit
sudden entry of large quantities of lake water into the pit.
(2) In such pits, or in mined-out pits which were reconnected
to the lake, the rate of downward leakage would be greatly in-
creased due to the increase in vertical hydraulic gradient result-
ing from the reduction in thickness of the confining beds of the
artesian aquifers in the pit floors.
(3) If cavernous conditions exist near the top of the lime-
stones underlying the lake, as they are known from other nearby
mining areas (See fig. 10.), then mining might foster the col-
lapse of cavern roofs, or might accidentally breach such a
cavern, and permit the draining of even larger amounts of water
than indicated in (1) and (2) above.
(4) Mining would lower the pit bottoms well below the piezo-
metric surface in some areas of the lake, and again significantly
reduce the thickness of the confining beds overlying the lime-
stones. This might lead to rupture of the reduced confining
bed by blow-out due to artesian pressure, and in this way provide
direct access of lake water to the limestones which would be as
effective as cavern collapse.
(5) The dams necessary for mining, if extended entirely
across the northern arms of the lake, would intercept a significant
part iof the surface-water inflow to the lake. Though this may
amount to only 3 to 12 inches of water per year over the lake
surface, the water budget would thus be unbalanced even further
than at present, and the lake level affected accordingly.
These comments all strongly indicate the necessity of detailed
engineering studies prior to the undertaking of mining operations
in the lake.


152






REPORT OF INVESTIGATION NO. 44


SCOTT LAKE
HISTORY AND NATURE OF THE PROBLEM
Early in 1953 the Board of County Commissioners of Polk
County requested that the U.S. Geological Survey investigate
the water problems in the Scott Lake area, south of Lakeland.
Property owners were concerned about the observed decline of
lake level because of the lake's recreational value and its value
as a source of water for the irrigation of adjacent citrus groves.
In 1953 a staff gage was installed on a boat dock on the south-
east shore of the lake. Later a recording gage was installed at the
same place, and wells were inventoried in the lake basin. Re-
cording gages were installed on an abandoned well in the second-
ary artesian aquifer (757-155-3) near the ridge crest, southeast
of the lake, and on a well in the nonartesian aquifer (758-156-5)
on the north shore of the lake. (See fig. 4.)
Both the secondary artesian and Floridan aquifers are present
in the ridge section around Scott Lake and both aquifers are in
use, but wells into the Floridan aquifer are much more numerous.
Because of the pump installations, very few of the wells around
the lake shore can be used for water-level measurements. Ob-
served and reported water levels indicate, however, that the water
level in the Floridan aquifer may be as much as 80 feet below that
of the secondary artesian aquifer on the basin floor, and it is
approximately 20 feet below that of the secondary artesian aqui-
fer on the ridge top east of Scott Lake.
Figures 33 and 34 show the hydrographs of Scott Lake and
wells in the Scott Lake area. The hydrographs of wells shown in
figure 34 are arranged with the topographically highest well at
the top of the figure and the lowest at the bottom. The locations
of wells in the Floridan, nonartesian, and secondary artesian
aquifers, in the vicinity of Scott Lake, are shown on figures 35
and 36.
Figure 33 shows that the hydrographs of Scott Lake and well
758-156-5 intersect, indicating periods of reversal in the direction
of ground-water flow in the nonartesian aquifer in one part of the
shore area. Figure 34 shows that the water level in well 758-156-1
in the same general part of the shore area also fluctuates above
and below the level of Scott Lake. In that part of the shore area
during periods of normal rainfall, recharge to the nonartesian
aquifer is sufficient to maintain a hydraulic gradient from the
drainage divide downward to the lake, indicating discharge from
the aquifer into the lake. As in much of Polk County, a down-


153







FLORIDA GEOLOGICAL SURVEY


(Secondary ortesiaon aquifer)
Well 757-155-3.6 miles SE. at Loheland





Well 757-155-6. 6 miles SE. of Lokelond

S90-- -r(Floridn aquifer)--
886---- --
86--


94. 84-------------------
;954 1955 1956 1957 1958 1959 1960
Figure 33. Hydrographs of water levels in Scott Lake and in wells 758-
156-5, 757-155-3, and 757-155-6, 1954-1960.

ward hydraulic gradient also exists between the water table and
the piezometric surfaces of the underlying artesian aquifers, and
water is being lost from the nonartesian aquifer to the artesian
aquifers. The water table .fluctuates slightly with day-to-day
rainfall. The rate of decline of the water table is dependent on
rainfall, recharge to the limestones, and discharge to the lake.
During extended periods of below-normal rainfall, the water
table in the area of the two wells is lowered rapidly by ground-
water inflow to the lake from the aquifer. Eventually the hy-
draulic gradient on the lake basin floor becomes very flat, and
ground-water inflow to the lake is reduced to a very small amount.
During periods of low evaporation the water table declines in a
direct relationship with lake level, although the quantities of
water lost are not greatly different. The decline is at a ratio of


154


IR1


S ,
S160-1

116
* leO6-





o
H 114


S110



1080
'02;
1oi







REPORT OF INVESTIGATION NO. 44 155




18 9 t I I I i 1 l i I I I I 1 1 i I 1 I i l l t i I

188
Well 757-157-3
187/ -mile southwest
Sof Scott Lake
186- -.\ Depth of well 20 ft
Depth of casing 20ft.
185 4

W-J 1 84___
tJ
" 183

182

S181

S> 8 I I I I I I I I I I l I I I
m

"w Well 758-157-4
" 173 mile northwest
z 73, of Scott Lake
J 172 -Depth of well 42 ft.
> ^ Depth of casing unknown
- 171

i- 170/ 757-1
\ Well 757-157-4


Figure 34. Hydrographs of water levels in wells in the nonartesian aquifer
in the Scott Lake area.






FLORIDA GEOLOGICAL SURVEY


ar58s 5' 56' 81055'

Figure 35. Map showing water levels and other features of the Scott Lake
Lake area, July 1956.


156








REPORT OF INVESTIGATION No. 44 157




81058' 57' 56'. 81055'
2800 -28o00'
EXPLANATION
2
A.
37 Well penetrating secondary
artesian aquifer
0
Well penetrating Floridan aquifer
7
1 /38
90 o 4 Upper number is well number on
90I 'figure 4; Lower number is
S90 altitude of water level,
59 in feet above mean sea level; 59'
shown with e where estimated.
3
o -3-
930 7


o 94
/ ^ 89















8756 3
e a, O 959 a 1







868


A7--
87J4









O I/4 1/2 3/4 Imile

67o56 II756
8158' 57' 56' 81 55



area, October 1959-February 1960.






FLORIDA GEOLOGICAL SURVEY


about 3 :1, which reflects the porosity of the aquifer (Stewart,
1963, table 9). During periods of high evaporation the decline
of the water table and lake level are more nearly equal, because
the lake is then losing greater quantities of water than the water
table.
The data from the nonartesian aquifer are sparse in the rest of
the lake basin, but it is believed that ground-water levels are
always above the lake level in most of the basin.
Figure 33 shows the hydrographs of well 757-155-3, in the
secondary artesian aquifer, and that of Scott Lake. The major
drawdowns in the well in the spring months are caused by local
heavy pumping from multi-aquifer irrigation wells. An irrigation
well 50 feet away from 757-155-3 is open only to the Floridan
aquifer and is in daily use for domestic purposes, but pumping
of this well has not affected the water level in well 757-155-3.
WATER BUDGET
In order to evaluate the factors involved in the decline of
Scott Lake, it is necessary to establish a water budget for the
basin. The period January 1 through June 30, 1956, was used to
compute the budget for Scott Lake.
Surface outflow from the lake may occur through a water gap
in the sinkhole rim point A that opens westward from the north-
west bulge of the shoreline. The swampy channel occupying the
gap, called the "Lake Drain," is shown on figure 35. Phosphate
mining operations have interrupted the natural flow through the
Lake Drain at point C. Water may not flow through a canal on
the north side of mine pit D only when the lake level is above
an altitude of 168 feet. At point B, figure 35, a small earthen dam
prevents westward flow from the lake when the lake level is less
than 168 feet above msl. Thus, water will not flow out through
the Lake Drain if the lake-level is less than 168 feet above msl.
The maximum lake level during the budget period was 157 feet
above msl and no outflow occurred. A concrete control structure
has been built in the channel, on the lakeward side of the high-
way crossing the Lake Drain. The top of this dam is also 168
feet above msl, and the bottom of the control weir is 166 feet
above msl.
When the lake level is low, generally less than 166 feet above
msl, water is permitted to flow from an abandoned mine pit
(point E, fig. 35). Such was the case during the last half of the
budget period. This observed inflow, though not measured, is be-


158







REPORT OF INVESTIGATION No. 44


lieved to have been much less than one cubic foot per second.
For budgetary purposes, therefore, surface inflow is established,
but quantitatively unknown. Surface inflow also occurs intermit-
tently into the lake at its southwest arm, as shown on figure 35.
In the following computations the average coefficient of per-
meability for the nonartesian aquifer of 85 gpd per sq. ft. is taken
from Stewart (1963, table 9). The lake basin was divided into
segments and the ground-water inflow was computed for each
segment. Hydraulic gradients were approximated from data from
the observation wells shown in figure 35. On the basis of avail-
able well data, the average saturated thickness of the aquifer
around the shoreline is believed to be 25 feet, and possibly more.
Ground-water inflow was computed to be eqiuvalent to approxi-
mately 17 inches over the lake surface from January 1 through
June 30, 1956 (780,000 gpd). It is assumed that there is no lateral
ground-water outflow from the Scott Lake basin in the nonartesian
aquifer.
Rainfall at the Lakeland station was approximately 17 inches
from January 1 through June 30, 1956. Evaporation was estimated
to be 23 inches.
The lake level is lowered by pumping for citrus irrigation, as
well as by evaporation. Pump capacities and the duration of pump-
ing periods reported by owners of the irrigation systems indicate
that the total seasonal pumpage from the lake is approximately
38 million gallons. Such withdrawals are usually made from
January through April. The area of the lake surface is about 300
acres. According to these figures, average irrigation pumping
would amount to about 4.5 inches over the lake surface per season.
The water budget for Scott Lake may be summarized for the
period January 1 through June 30, 1956 as follows.
Gains: Inches of water
Rainfall 17
Surface inflow -+
Ground-water inflow 17
Total 34+
Losses:
Evaporation 23
Surface outflow 0
Irrigation pumping 4
Ground-water outflow in nonartesian aquifer 0
Total 27
differencee (downward flow to artesian aquifer) 7+


159






FLORIDA GEOLOGICAL SURVEY


These figures indicate a small surplus for the 6-month perioc,
however, figure 33 shows that the lake level actually declined 24
inches during the same period. The lake was recharging one or
more of the underlying artesian aquifers, through the lake bottom,
during this period and the recharge was equivalent to about 31
inches (24-inch loss plus 7-inch calculated surplus) over the lake
surface.
Figures 19, 35, and 36 show a high on the piezometric surface
of the secondary artesian aquifer adjacent to the lake and a slope
of this surface away from the lake, indicating recharge of the
aquifer by the lake. Observed and reported ground-water levels
and figure 23, however, show that the piezometric surface of the
Floridan aquifer is low under Scott Lake, indicating discharge
from that aquifer. If some recharge to the Floridan aquifer occurs
from Scott Lake, it is not enough to prevent the piezometric sur-
face of the aquifer from remaining at a low level in the vicinity
of the lake.
The coefficient of permeability used in this water budget is
applicable only to the nonartesian aquifer. Drilling data indicate
that this aquifer is underlain by more clayey and less permeable
materials at depth in the filled sinkhole lake basin. The general-
ized coefficient of permeability for the fill materials in the filled
sink under the lake bottom may be determined by transposition
of the formula Q = PIA, to P Q/IA. The vertical hydraulic
gradient, I, is the difference in head between the land and the sec-
ondary artesian aquifer, divided by the distance between the lake
bottom and the top of the aquifer. In well 757-156-2 this distance
is 49 feet. From the water budget, Q is 5 inches of water per
month, or 0.103 gpd-/sq. ft. The area, A is 1 sq. ft. Therefore:

P = 0.103 gpd/sq. ft. + (8 ft. + 49 ft.) X 1 sq. ft.
= 0.103 gpd/sq. ft. 0.153
.631 gpd/sq. ft.

which is substantially lower than that of the nonartesian aquifer.
The coefficient derived here is a summation of the thickness and
permeabilities of all the materials through which the water
leaking from the lake to the aquifer must pass. It may nct
represent any single one of these accurately, and the materials
underlying the lake bottom may not be uniform, hence rate cf
recharge may differ considerably over the lake basin.


160






REPORT OF INVESTIGATION No. 44


CONCLUSIONS
The level of Scott Lake is lowered only 4.5 inches by irriga-
tion pumping from the lake in an average irrigation season if all
the pumping stations available in 1959 were used simultaneously.
This is approximately equal to one month's evaporation from the
lake surface.
The lake is leaking and furnishing appreciable quantities of
recharge to the secondary artesian aquifer, as are parts of the
lake basin slope. Figure 19 indicates a piezometric high at the
southwest side of the lake. A similar high on the east side of the
lake may be prevented by discharge through the aquifer eastward
towards Lake Hancock. This discharge is indicated by the re-
entrants in the piezometic contours between the two lakes. Some
of the leakage from Scott Lake may be going into the Floridan
aquifer, but this has not been definitely established.
The investigation has shown that the fluctuations of Scott
Lake are due to entirely natural conditions (except for minor
irrigation use), and that these fluctuations reflect the sum of all
the factors of the water budget of the lake. A reduction of pres-
sure in the secondary artesian aquifer, by discharge from wells
in the vicinity of the lake, will increase the vertical hydraulic
gradient between the lake and the aquifer and thereby increase
the rate of leakage. At other times, generally during the fall and
winter months, the lake receives much more water than is being
lost and as a result the lake level rises (fig. 33).


SUMMARY
Polk County approximately in the center of peninsular Florida
comprises an area of about 1861 square miles. It is part of the
central highland area that trends along the longitudinal axis of
the peninsula. Three long irregular ridges are major topographic
features in the county on which are located the centers of popula-
tion. The well-drained ridges and inter-ridge areas are extensively
used for citrus groves. Most of the area of the county is broad,
poorly drained lowlands which is devoted to cattle ranching and
phosphate mining. Total relief in the county is 255 feet (50 to
-05 feet above msl). Surface drainage is poorly developed in the
county Sinkhole basins of subsurface drainage are numerous and
riany of them contain lakes.
Surficial sands are underlain by phosphatic clays and marls


161






FLORIDA GEOLOGICAL SURVEY


which range in age from Miocene to Recent. These are underlain
by porous limestones which range in age from middle Eocene to
Miocene. Though covered by the overlying sands and clays, the
area is a buried limestone terrane. The formations dip, and thicken,
southward from a structural high located in the northern part
of the county. This high is the southern end of the Ocala,Uplift.
A previously unmapped area of rock outcrop in northwestern Polk
and adjacent counties has been mapped and described. The out-
crop area contains silicified remnants of the contact zone between
the Oligocene Suwannee Limestone and Eocene Crystal River
Formation.
Previous workers dated the Ocala uplift as late Oligocene or
early Miocene, and have postulated that the rocks of the area
respond to structural deformation by fracturing, rather than by
bending or warping. This investigation shows that a structural
high existed in this area since the deposition of the Avon Park
Limestone (middle Eocene). Considerable erosion occurred after
the deposition of each of the formations in the area except the
Inglis and Williston Formations of the Ocala Group. These
erosional intervals were probably accompanied by repeated up-
lift of the structural high. Structural studies indicate that the
rocks were probably faulted as a result of the uplift. Vertical
displacement along the faults generally ranges from 10 to 50
feet, with a few local displacements up to 300 feet or more. Fault-
ing probably continued at least through the Miocene.
Ground water in Polk County occurs under both nonartesian
and artesian conditions. The water table is close to land surface
in lowland areas, but may be 70 feet or more below land surface
in the ridge area. The nonartesian aquifer consists of undiffer-
entiated plastic deposits which may range in age from Miocene
to Recent. The thickness of this aquifer generally ranges from 1 to
250 feet, and where it is more than 10 feet thick it will generally
furnish sufficient water to supply small domestic and irrigation
requirements. Although the aquifer is not extensively used, the
water is fresh and generally acidic. Locally, it may be highly
mineralized due to commercial fertilizers used in agriculture or by
other types of pollution.
The uppermost artesian aquifer occurs in the lower part cf
the undifferentiated plastic deposits underlying the nonartesian
aquifer. The clay contains pebble-phosphate which is mined
extensively in the southwestern part of the county. The deposits
may range in age from Miocene to Pleistocene. The thickness and


162







REPORT OF INVESTIGATION NO. 44


,aeal extent of this aquifer is unknown. It is not extensively
used.
The secondary artesian aquifer is composed of the limestone
units of the Hawthorn Formation of Miocene age. The aquifer is
generally present over the southern three-fourths of the county
and is used more than either of the two overlying aquifers. The
principal use is for domestic supply, but in the Lakeland area it
is also important as a source for irrigation supplies. The lime-
stone is clayey and the permeability is generally low. However,
the existence of caverns developed along fractures greatly
increases the productivity of the aquifer and locally, such features
are large enough to supply large-diameter irrigation wells. Water
from the aquifer is fresh and moderately hard.
The Floridan aquifer is the principal source of water in the
county. The aquifer is of vast areal extent, underlying all of
Florida and parts of adjacent states. In Polk County it is composed
of a thick section of limestones that range in age from middle
Eocene to Oligocene and function as a single aquifer. The presence
of anhydrite and gypsum in the lower few feet of the Avon Park
Limestone and in the underlying Lake City Limestone in the
Lakeland area indicates that the Avon Park is the basal unit of
the aquifer in that area and probably the remainder of the county
as well. Considerable horizontal flow occurs within the cavern
systems in the aquifer. The flow is sufficient to cause linear draw-
down in the aquifer along the course of the caverns which appear
as troughs in the piezometric surface. The aquifer is under
artesian conditions except for a small area along the crest of the
northern part of the Lake Wales ridge, where evidence indicates
!that it may be under nonartesian conditions.
Water wells drilled into the Floridan aquifer range from 2 to
30 inches in diameter and from 10 to 1,400 feet in depth. The
largest known yield from a well in this aquifer was 8,000 gpm,
with 23 feet of drawdown, from a 24-inch well, 1,200 feet deep.
Water in the aquifer is fresh and moderately hard. Well yield is
primarily controlled by penetration of solutional features.
The two principal industries in the area-the growing and
processing of citrus fruits and the mining and processing of
Sabble-phosphate-use large quantities of ground water. The
g -owth of population has greatly increased municipal and domes-
t' consumption in recent years. During 1959 ground-water pump-
ae from all sources in the county was estimated to be approxi-
n ately 80 billion gallons.


163






FLORIDA GEOLOGICAL SURVEY


Polk County overlies the highest point on the piezometr-c
surface of the Floridan aquifer in peninsular Florida. It has long
been thought that Polk County, therefore, represented a
principal recharge area for the aquifer, and that most of this re-
charge was supplied by downward leakage from the numerous
sinkhole lakes of the area. Investigation of the Lakeland area,
however, has shown that although some recharge may come from
these lakes, the amount may be small; most of the downward
leakage from some of these lakes is recharging the secondary
artesian aquifer rather than the Floridan aquifer. Many of the
sinkhole lakes overlie troughs in the piezometric surface, there-
fore, leakage to the aquifer is not sufficient to cause doing of
the piezometric surface. The present investigation shows that
the Floridan aquifer is recharged, mainly by the slow downward
percolation of water through the confining beds over most of the
county. The total recharge to the aquifer is estimated to be only
a few inches of water per year (approximately 120 billion gal-
lons) which is substantially less than the amounts lost to evapo-
transpiration or to surface runoff.
Lake Parker, in eastern Lakeland, also recharges the artesian
aquifers at a slow rate. Large withdrawal of ground water is
anticipated in the area along the north shore of the lake, and it
may lower the lake level by reducing the ground water discharged
into the lake; it may even establish hydraulic gradients away
from the lake, thereby increasing losses through the lake bottom.
It appears, however, that similar large withdrawal east of the lake
did not affect the lake level.
Scott Lake, a sinkhole lake south of Lakeland, recharges the
secondary artesian aquifer. The effect of withdrawal from the
lake for irrigation of citrus groves is equivalent to lowering the
lake level approximately 4.5 inches per season, but the principal
reasons for large seasonal declines of the lake level are: (1) con-
tinuing downward leakage to the secondary artesian aquifer, (2)
evaporation from the lake surface, and (3) below-normal rain-
fall, which has caused the water table to decline and has reduced
the ground-water discharge into the lake.


164







REPORT OF INVESTIGATION NO. 44


REFERENCES

/.ltschuler, Z. S.
1956 (and Jaffe, E. B., and Cuttitta, Frank) The aluminum phos-
phate zone of the Bone Valley Formation, Florida, and its ura-
nium deposits: U.S. Geol. Survey Prof. Paper 300, p. 495-504.
1958 (and Clarke, R. S., Jr., and Young, E. J.) Geochemistry of
uranium in apatite and phosphorite: U.S. Geol. Survey Prof.
Paper 314-D
1960 (and Young, E. J.) Residual origin of the "Pleistocene" sand
mantle in central Florida uplands and its bearing on marine ter-
races and Cenozoic uplift U.S. Geol. Survey Prof. Paper 400-B,
p. 202-207.
SAlverson, D. C. (see Carr, W. J.)
Anders, R. B. (see Peek, H. M.)
Applin, E. R. (also see Applin, Paul L.)
1945 (and Jordan, Louise) Diagnostic foraminifera from subsurface
formations in Florida: Jour. Paleontology, v. 19, no. 2, p. 129-148,
pls. 18-21, 2 test figs.
Applin, Paul L.
1944 (and Applin, E. R.) Regional subsurface stratigraphy and struc-
ture of Florida and southern Georgia: Am. Assoc. Petroleum
Geologists Bull., v. 28, no. 12, p. 1673-1753.
Baker, D. R. (see Kohler, M.A.)

Bergendahl, M. H.
1956 Stratigraphy of parts of DeSoto and Hardee Counties, Florida:
U.S. Geol. Survey Bull. 1030-B.

Bermes, B. J.
1958 Interim report on geology and ground-water resources of Indian
River County, Florida: Florida Geol. Survey Inf. Circ. 18.

Bishop, Ernest W.
1956 Geology and ground-water resources of Highlands County, Flor-
ida: Florida Geol. Survey Rept. Inv. 15.
Black, A. P.
1951 (and Brown, Eugene) Chemical character of Florida's waters.
Florida State Bd. Conserv., Div. Water Survey and Research,
Paper 6.

Elade, L. U. (see Cathcart, J. B.)

Flaney, Harry F.
1956 Comments on Estimating Evaporation, by H. L. Penman: Am.
Geophys. Union Trans., v. 37, no. 1, p. 46-48.

Lrown, Eugene (see Black, A. P.; Cooper, H. H., Jr.)


165






FLORIDA GEOLOGICAL SURVEY


Carr, W. J.
1953 (and Alverson, D. C.) Stratigraphy of Suwannee, Tampa and
Hawthorn formations in Hillsborough and parts of adjacent
counties, Florida, in Geologic Investigations of radioactive de-
posits semiannual progress rept., June 1, 1953 to Nov. 30, 1953:
U.S. Geol. Survey TEI-390, issued by U.S. Atomic Energy Comm.
Tech. Inf. Service, Oak Ridge, Tenn., p. 175-185.
1959 Stratigraphy of middle tertiary rocks in part of west-central
Florida: U.S. Geol. Survey Bull. 1092.

Cathcart, J. B.
1952 (and Davidson, D. F.) Distribution and origin of phosphate in
the land-pebble phosphate district of Florida: U.S. Geol. Survey
TEI-212, issued by U.S. Atomic Energy Comm. Tech. Inf. Serv-
ice, Oak Ridge, Tenn.
1953 (and Blade, L. U.; Davidson, D. F.; and Ketner, K. B.) Geology
of the Florida land-pebble phosphorite deposits: Internat. Geol.
Cong., 19th, Algiers, 1952, Comptes rendus, sec. 11, pt. 11,
p. 77-91.
1959 (and McGreevy, L. J.) Results of geologic exploration by core
drilling, 1953, land-pebble phosphate district Florida: U.S. Geol.
Survey Bull. 1046-K.

Cherry, R. N. (see Pride, R. W.)

Clarke, R. S., Jr. (see Altschuler, Z. S.)

Cole, W. Storrs
1941 Stratigraphic and paleontologic studies of wells in Florida:
Florida Geol. Survey Bull. 19.
1945 Stratigraphic and paleontologic studies of wells in Florida-
No. 4: Florida Geol. Survey Bull. 28.

Collins. W. D.
1925 Temperature of water available for industrial use in the United
States: U.S. Geol. Survey Water-Supply Paper 520-F.
1928 (and Howard, C. S.) Chemical character of waters of Florida:
U.S. Geol. Survey Water-Supply Paper 596-G.

Cooper, H. H., Jr. (also see Stringfield, V. T.)
1944 Ground-water investigations in Florida (with special reference
to Duval and Nassau Counties): Am. Water Works Assoc. Jour.,
v. 36, no. 2, p. 169-185.
1953 (and Kenner, W. E., and Brown, Eugene) Ground water in cen-
tral and northern Florida: Florida Geol. Survey Rept. Inv. 10.
Cooke, C. W.
1939 Scenery of Florida, interpreted by a geologist: Florida Geo.
Survey Bull. 17.
1945 Geology of Florida: Florida Geol. Survey Bull. 29.
Cuttitta, Frank (see Altschuler, Z. S.)


166







REPORT OF INVESTIGATION NO. 44


Davidson, D. F. (also see Cathcart, J. B., 1952, 1953)
1952a Relation of the "topography" of the Hawthorn Formation to size
of phosphate particles in the deposits, and to topography, in the
northern part of the land-pebble phosphate field, Florida: U.S.
Geol. Survey TEM-337, issued by U.S. Atomic Energy Comm.
Tech. Inf. Service, Oak Ridge, Tenn.
1952b Grain size distribution in the surface sands and the economic
phosphate deposits of the land-pebble phosphate district, Florida:
U.S. Geol. Survey TEM-362, issued by U.S. Atomic Energy
Comm. Tech. Inf. Service, Oak Ridge, Tenn.
Espenshade, G. H.
1963 (and Spencer, C. W.) Geology of phosphate deposits of northern
peninsular Florida: U.S. Geol. Survey Bull. 1118.
Fenneman, N. M.
1938 Physiography of the eastern United States: New York; McGraw-
Hill Book Co.
Ferguson, G. E. (also see Parker, C. G.)
1947 (and Lingham, C. W.; Love, S. K.; and Vernon, R. 0.) Springs
of Florida: Florida Geol. Survey Bull. 31.
Follansbee, Robert
1934 Evaporation from reservoir surfaces: Am. Soc. Civil Engineers
Trans., v. 60, p. 704-747.
Gunter, Herman (also see Sellards, E. H.)
1931 (and Ponton, G. M.) The need for conservation and protection
of our water supply with special reference to waters from the
Ocala Limestone: Florida Geol. Survey 21-22d Ann. Rept., p.
43-58.
Heath, Richard C.
1961 Surface-water resources of Polk County, Florida: Florida Geol.
Survey Inf. Circ. 25.
Hetherington, M. F.
1928 History of Polk County, Florida: The Record Company, St. Au-
gustine, Florida.
Horton, Robert E.
1943 Evaporation maps of the United States: Am. Geophys. Union
Trans., pt. II, p. 743-753.
Howard, C. S. (see Collins, W. D.)
Jaffe, E. B. (see Altschuler, Z. S.)
Jordan, Louise (see Applin, E. R.)
Kenner, W. E. (see Cooper, H. H. Jr.)
.etner, K. B. (also see Cathcart, J. B.)
1959 (and McGreevy, L. J.) Stratigraphy of the area between Her-
nando and Hardee Counties, Florida: U.S. Geol. Survey Bull.
1074-C.


167






FLORIDA GEOLOGICAL SURVEY


Klein, Howard
1954 Ground-water resources of the Naples area, Collier County, Flor-
ida: Florida Geol. Survey Rept. Inv. 11.
Kohler, M. A.
1959 (and Nordenson, T. J., and Baker, D. R.) Evaporation maps for
the United States: U.S. Weather Bureau Tech. Paper 37.
Koo, Robert C. J.
1953 A study of soil moisture in relation to absorption and transpira-
tion by citrus: Univ. of Florida, Doctoral dissertation, Gaines-
ville, June.
Lingham, C. W. (see Ferguson, G. E.)
Love, S. K. (see Ferguson, G. E.; Parker, C. G.)
McGreevy, L. J. (see Cathcart, J. B.; Ketner, K. B.)
MacNeil, F. Sterns
1950 Pleistocene shorelines in Florida and Georgia: U.S. Geol. Survey
Prof. Paper 221-F.

Mansfield, George R.
1942 Phosphate resources of Florida: U.S. Geol. Survey Bull. 934.


Matson, G. C
1913

Meinzer, O. I


(and Sanford, Samuel) Geology and ground waters of Florida:
U.S. Geol. Survey Water-Supply Paper 319.
E.


1923a The occurrence of ground water in the United States, with a
discussion of principles: U.S. Geol. Survey Water-Supply Paper
489.
1923b Outline of ground-water hydrology with definitions: U.S. Geol.
Survey Water-Supply Paper 494.


Menke, C. G.
1961 (and Meredith, E. W., and Wetterhall, W. S.) Water resources
of Hillsborough County, Florida: Florida Geol. Survey Rept.
Inv. 25.
Meredith, E. W. (see Menke, C. G.)
Meyer, A. F. (also see Pride, R. W.) *
1942 Evaporation from lakes and reservoirs: Minnesota Resources
Comm., St. Paul, Minn.
Nordenson, T. J. (see Kohler, M. A.)
Parker, C. G.
1955 (and Ferguson, G. E.; Love, S. K.; and others) Water resources
of southeastern Florida: U.S. Geol. Survey Water-Supply Paper
1255.
Peek, H.M.
1951 Cessations of flow of Kissengen Spring in Polk County, Florida:
Florida Geol. Survey Rept. Inv. 7, pt. III.


168








REPORT OF INVESTIGATION NO. 44 169

1955 (and Anders, R. B.) Interim report on the ground water resources
of Manatee County, Florida: Florida Geol. Survey Inf. Circ. 6.
1958 Ground-water resources of Manatee County, Florida: Florida
Geol. Survey Rept. Inv. 18.
1959 The artesian water of the Ruskin area of Hillsborough County,
Florida: Florida Geol. Survey Rept. Inv. 21.
Perman, H. L.
1956 Estimating Evaporation: Am. Geophys. Union Trans., v. 37,
no. 1, p. 43-46.

Pettijohn, F. J.
1949 Sedimentary Rocks: New York; Harper & Brothers.

Pirkle, E. C.
1957 The Hawthorn and Alachua Formations of Alachua County,
Florida: A paper presented at the First Ann. Meeting of Soc.
Mining Engrs. of AIME, and S. E. States Mining Conferences,
Tampa, Fla., Oct. 15-18.
Ponton, G. M. (see Gunter, Herman).
Pride, R. W.
1961 (and Meyer, F. W., and Cherry, R. N.) Interim report on the
hydrologic features of the Green Swamp area in Central Flor-
ida: Florida Geol. Survey Inf. Circ. 26.
1964 (and Meyer, F. W., and Cherry, R. N.) Hydrology of the Green
Swamp area in central Florida: Florida Geol. Survey Rept. of
Inv. 42.

Puri, Harbans S.
1953a Zonation of the Ocala Group in peninsular Florida (abs.) : Jour.
Sed. Petrology, v. 23, p. 130.
1953b Contributions to the study of the Miocene of the Florida pan-
handle: Florida Geol. Survey Bull. 36.
1957 Stratigraphy and donation of the Ocala Group: Florida Geol.
Survey Bull. 38.
Reitz, H. J. (see Wander, I. W.)
Sanford, Samuel (see Matson, G. C.)
Sellards, E. H.
1908 A preliminary report on the underground water supply of cen-
tral Florida: Florida Geol. Survey Bull. 1.
1913 (and Gunter, Herman) The artesian water supply of eastern
and southern Florida: Florida Geol. Survey 5th Ann. Rept.,
p. 105-290.
Spencer, C. W. (see Espenshade, G. H.)
';tewart, H. G., Jr.
1959 Interim report on the geology and groundwater resources of
northwestern Polk County, Florida: Florida Geol. Survey Inf.
Circ. 23.







FLORIDA GEOLOGICAL SURVEY


1963 Records of wells and other water-resources data in Polk County:
Florida: Florida Geol. Survey Inf. Circ. 38.
Stringfield, V. T.
1935 The piezometric surface of artesian water in the Florida Penin-
sula: Am. Geophys. Univ. Trans., p. 524-529.
1936 Artesian water in the Florida peninsula: U.S. Geol. Survey Wa-
ter-Supply Paper 773-C.
1951a (and Cooper, H. H., Jr.) Economic aspects of ground water in
Florida: Mining Eng., June, p. 525-533.
1951b Geologic and hydrologic features of an artesian submarine
spring east of Florida: Florida Geol. Survey Rept. Inv. 7, pt. 2.
Unklesbay, A. G.
1944 Ground-water conditions in Orlando and vicinity, Florida: Flor-
ida Geol. Survey Rept. Inv. 5.
U.S. Bureau of Census
1957 1954 Census of Agriculture, Counties and state economic areas
-Florida: v. 1, pt. 18.
U.S. Bureau of Mines
1959 Minerals yearbook, v. 3, Area Repts., table 5, p. 266.
Vernon, R. O. (also see Ferguson, G. E.)
1951 Geology of Citrus and Levy Counties, Florida: Florida Geol.
Survey Bull. 33.
Wander, I. W.
1951 (and Reitz, H. J.) The chemical composition of irrigation water
used in Florida citrus groves: University of Florida Agr. Exper.
Sta. Bull. 480.
Warren, M. A.
1944 Artesian water in southeastern Georgia with special reference to
the coastal area: Georgia Geol. Survey Bull. 49.
Wenzel, L.K.
1942 Methods for determining permeability of water-bearing materi-
als, with special reference to discharging-well methods: U. S.
Geol. Survey Water-Supply Paper 887.
Wetterhall, W. S. (see Menke, C. G.)
White, William A.
1958 Some geomorphic features of central peninsular Florida: Florida
Geol. Survey Bull. 41.
Wyrick, Granville G.
1960 The ground-water resources of Volusia County, Florida: Florida
Geol. Survey Rept. Inv. 22.
Young, E. J. (see Altschuler, Z. S., 1958, 1960)


170







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Ground-water resources of Polk County ( FGS: Report of investigations 44 )
CITATION SEARCH THUMBNAILS PDF VIEWER PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00001231/00001
 Material Information
Title: Ground-water resources of Polk County ( FGS: Report of investigations 44 )
Series Title: ( FGS: Report of investigations 44 )
Physical Description: x, 179 p. : illus., maps (2 fold.) ; 23 cm.
Language: English
Creator: Stewart, Herbert G
Geological Survey (U.S.)
Publisher: s.n.
Place of Publication: Tallahassee
Publication Date: 1966
 Subjects
Subjects / Keywords: Groundwater -- Florida -- Polk County   ( lcsh )
Water-supply -- Florida -- Polk County   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by Herbert G. Stewart, Jr.
Bibliography: Bibliography: p. 165-170.
General Note: "Prepared by the United States Geological Survey in cooperation with the Division of Geology, the Board of County Commissioners of Polk County, and the Southwest Florida Water Management District."
 Record Information
Source Institution: 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: aleph - 000957326
oclc - 01725103
notis - AES0062
lccn - a 67007201
System ID: UF00001231:00001

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STATE OF FLORIDA
STATE BOARD OF CONSERVATION
DIVISION OF GEOLOGY




FLORIDA GEOLOGICAL SURVEY
Robert O. Vernon, Director






REPORT OF INVESTIGATIONS NO. 44





GROUND-WATER RESOURCES
OF POLK COUNTY

By
Herbert G. Stewart, Jr.











Prepared by the
UNITED STATES GEOLOGICAL SURVEY
in cooperation with the
DIVISION OF GEOLOGY
the
BOARD OF COUNTY COMMISSIONERS OF POLK COUNTY
and the
SOUTHWEST FLORIDA WATER MANAGEMENT DISTRICT
1966









FLORIDA STATE BOARD

OF

CONSERVATION


HAYDON BURNS
Governor


TOM ADAMS
Secretary of State



BROWARD WILLIAMS
Treasurer



FLOYD T. CHRISTIAN
Superintendent of Public Instruction


EARL FAIRCLOTH
Attorney General



FRED O. DICKINSON
Comptroller



DOYLE CONNER
Commissioner of Agriculture


W. RANDOLPH HODGES
Director









LETTER OF TRANSMITTAL


7torida geological Sarveu

Tallahasseo



August 16, 1966

Honorable Haydon Burns, Chairman
Florida State Board of Conservation
Tallahassee, Florida

Dear Governor Burns:
The Division of Geology of the State Board of Conservation is
publishing, as Report of Investigations No. 44, a detailed geologic
and hydrologic study, covering the "Ground Water Resources of
Polk County." This report was prepared by Mr. Herbert G. Stewart,
Jr., geologist with the U. S. Geological Survey, in cooperation with
the Board of Conservation, the Board of County Commissioners of
Polk County, and the Southwest Florida Water Management Dis-
trict.
The detailing of the geology and hydrology of Polk County pro-
vides the necessary data on many of Florida's phosphate deposits,
on a large part of the Green Swamp water management area, and
will contribute toward the further development of this area.


Respectfully submitted,
Robert O. Vernon, Director
Division of Geology



















































Completed Manuscript received
August 16, 1966
Published for the Florida Geological Survey
By Rose Printing Company
Tallahassee
1966







CONTENTS
Page
Abstract ..--........------.. ......-......... ...-...-...-...--.......-.......-.....................--- .... 1
Introduction ----........ ...... .....-.......-..... ....-..- ..----- .........-................................ 2
Purpose and scope of investigation ......-.............---..-.....-..---...............-.. 2
Previous investigations ...................--.....--....---- ...----- .. .....-..-...-- ....-..-... 3
Methods of investigation -....-......-----------...-...-..--...--------------.............. 4
Well-numbering system -----------------......................... ..- ..................... 6
Acknowledgements ........-....-.-----...... ....-......-.......-- ...------...----. ...-... 7
Geography --....------......-..-...........--- ........-- ..---- ............--..........--.... ....-..-...-....... 7
Location ....................................................................----- ........... ...........---- 7
Topography ...................-...... -------.......................--........................... ........ ..- 9
Climate .....--------------------.--.......... ....... ----------------.......... ..................................... 11i
Transportation .....--.........................-. ....-.................................. 12
Agriculture ............. .............................................................. ........................ 13
Agriculture ------------------------------------- ---------------------------------------- 13
M mineral resources ............-..-................--------... .. .. ............ .....--- ..- 13
Industry ------------------------------------------------------------------------ --------- 14
GeologIndustry ..y- -- ....--.-.- .. ....... .......................... .............................. .. 14

Stratigraphy ..................- ..........-..................... ...... ........................... .... 14
Eocene Series ----...--..........---------------- ------.. .. ..........---..-- 20
Oldsmar Limestone -.......--..---........--------------.. --......-....-- 20
Lake City Limestone --------.. --.... ----.......-- ---.------------....-- ----- 28
Avon Park Limestone .-..-.. ........---....-. ........-..--- --....----- 30
Ocala Group ...--.....................----------- ....-- ...-- ...-......---..--- 33
Inglis Formation ---........--......--.......-- ..-- ...- ------.-----..... 33
Williston Formation ...-----------... --..--....-. ... .....--....-...-------..--- 35
Crystal River Formation -...-...-....-.....-...--....-- .....----..------ 35
Oligocene Series .-...-..................-------------- .........------------ 38
Suwannee Limestone -.....---.........-- .............----- ..........--------- 38
Miocene Series -..................... ---..........-..--------------- ---------.------ 39
Tampa Formation ........-................. .............----- ............--------- 40
Hawthorn Formation .....-----.......--.........---- .......------ 45
Undifferentiated plastic deposits -------................ -- -...--.............. 46
Phosphate deposits -----...----... .....--- ..-.....-- .... .------..----- 47
Coarse plastic deposits .-..........------ ..--...----- ------.--.------. 47
Structure ----.......-----------....-..-.......--. .... .....................------------.. -- 48
History of structural movements ........-...........----..............---..---- 51
Solution features .....--........-..-....---------- --------- ---- 52
Cavities ..-----------................ -----------................---------- 62
Sinkholes ..................------ .......--....--- ..-- ..-- ......------- ---------------. 65
Hydrology .--------..--...-......--..--------..--- ..------------------ ------------- 69
Surface water ..-..-..............-...... ---- ---- ---------------------- 70
Streams ........---------..............-- .-- ------- ------------- --------------------70
Lakes -.---....--...........---..-....---. -----.--- ------------------------------ 72
Evapotranspiration ...............----......--- ....-.............. ........----- .--------- 76
Ground water ..-..........--- ..... ---------- ------------------------- 77
Occurrence ........------..------------- --------------------------- 77
Nonartesian aquifer ........ ----.--- ----------------------------------------- 78
Characteristics .....--.......-..---.....-....--- ......-... -------- ------------- 78
Water-level fluctuations ......----.......-........-------.. --------------- 79







CONTENTS Page
Uppermost artesian aquifer -......... --------..... .........-...--................- 8
Secondary artesian aquifer --.........----------- ---.---......-......... 83
Characteristics ...........-..... ....... ... ............................ 83
The piezometric surface -----..-..-....-------..........-.. ........... 85
Areas of artesian flow -.......--....-----------... --..-----............ 88
Water-level fluctuations ........-------.....-..-..................- 89
Floridan aquifer -...-.--.-----.-----.......... --...-..--.--.................. -89
Characteristics ------.. -.....----.... -..-.. -- ........-..-....-..... ... 89
The piezometric surface .----- -------........--- ------............ 91
Areas of artesian flow ---.....-- ...---...........---- .......-- ... 100
Water-level fluctuations --- -- -----........... ........................ 100
Water-level history ..--....-- ..--..... --... ---- ..... ...-- -............ 102
Hydraulics .--.--------...... -.......-----. --. ----------------...---........-...- 105
Specific capacity of wells .----..... -----...-..--..----............... 105
Vertical movement of water -..- ...........--- -...--...- -................... 112
Pumping tests ..--..........-........... ..--............-- ...... .....-- -- .-----. ....-... 112
Hydrologic properties of selected limestone core samples --................ 115
Recharge --------..--------..---...--.-- ---. ----........- ---------....-...... 116
Nonartesian aquifer ----... --....... --------....----........ ........... 116
Uppermost artesian aquifer -.~-----------...............--.. ----- 117
Limestone aquifers --...-..----.---. .------------.......... --- ---. 117
Secondary artesian aquifer .-. .......-......................-...--- -. 120
Floridan aquifer ....... ---- --------........-.... -......... ---...... ....... 121
Quality of water ...... ....... -----.......-..-- ---------129
Chemical constituents ------- ---------------....... ......-----..... -.... 129
Change of chemical quality with time ....-..........--..--..-- ..--.............. 133
Change in chemical quality with depth ............-----....---... .........-- ....- 133
Water temperature .. --.--..--..-----....-... --..-....... .... -- 134
Summary of chemical quality .--. --......--... .. .....---....-- ..--.--. 135
Water use -. ..-.-...................------.-- -----------. 136
Public supply .- ....--------- ..-- ................--- ..---- ...-..136
Domestic supply .- ....- ---....... -... ---.-------------...-.....-..-..-... 138
Industrial supply ------..-..---...- ..----------... -. -------- 138
Irrigation supply .--- .--......---------- --- .......-............--........ 139
Miscellaneous supplies -----......- .. ...- --------- -............... ....... 140
Summary of water use ---.-- ---------........~ .........-----......--.--..-. 141
Special problems .. --~...............----.... --..-........------ 141
Lake Parker -----....--.........-..--.........------. ------------ 141
History and nature of problem .-...-......-........-......-.....-- ..------ 141
W ater budget ............- .......... ---- -....-.... ............-... ...---------... 147
Conclusions ---.......-... ..--------.-...........--...... --------151
Scott Lake .........-..----....--... -....---.------...............-.----- 153
History and nature of the problem ....--------....- --..-................----- .. 153
W ater budget .....-.....-- -- -----..-....-. .-....-.. .. ~................................---- 158
Conclusions ..-..-..........--..--- ..-- ..----..------- --- .--...------ 161
Summary .....-----.......-- .--.--....... .....-........... ....................................-------- --- 161
References .........--- ..-- ...-- ....-----................-- -------- 165







ILLUSTRATIONS

Figure Page
1 Map of Florida showing the location of Polk County and the well-
numbering system .---.......---- .......-- ...-----...... ..............--- ..........-- 6
2 Topographic map showing major physiographic features ............... 8
3 Graph showing total annual rainfall at Lakeland, 1915-59 ---......- 11
4 Map showing the location of selected wells --..---...... Facing page 14
5 Geologic map of the pre-Miocene formations ----..........----............ 34
6 Geologic sections along lines A-A' and B-B'. Sections located on
Figure 5 ....---------....-----... -------.... ----------........--..--..-- .. 43
7 Geologic sections along lines C-C' and D-D'. Sections located on
Figure 5 ....---.....--......----......- ...-..-- .... .......-------.... ........... ........-- 44
8 Structure-contour map on top of the Inglis Formation --...--....-------.. 50
9 Map showing the location of wells penetrating solution features in
the limestone ..----------------- ----.. .... ------................ .......-- ...-- .. 63
10 Map showing location of recent sinkhole collapses -------...... ---........ -- 66
11 Photographs of recent sinkhole collapses ...--...... ..........................-- 68
12 Hydrographs of water levels in Lakes Wire, Hollingsworth, Deeson,
Crystal, and Bonny near Lakeland and rainfall at Lakeland,
1954-59 ...------......-- ............ .... ...------.. ----.......... ............ 74
13 Water-table contour of the Lake Parker area, June 25-30, 1956 .-... 80
14 Map showing water levels in selected wells penetrating the non-
artesian aquifer, (October 29, 1959 to February 4, 1960) .............. 81
15 Hydrograph showing fluctuations of the water table in a well near
Haines City (810-136-2) in the nonartesian aquifer --................ 82
16 Hydrographs showing fluctuations of the piezometric surface in a
well near Lakeland (803-153-18) and a well near Frostproof (744-
131-1) in the secondary artesian aquifer ------------............................ 85
17 Piezometric-contour map of the secondary artesian aquifer of Lake
Parker area (June 1956) -..-...-...--......--................------------------- 86
18 Piezometric-contour map of the secondary artesian aquifer in Lake
Parker area (October 1959 to February 1960) ---........--------... ...------ 87
19 Piezometric-contour map of the secondary artesian aquifer (Octo-
ber 1959 to February 1960) ---------.. ---................................-....----- 88
20 Piezometric-contour map of the Floridan aquifer (October 1959 to
February 1960) --.....................---- ..------...... ---.....--- Facing page 90
21 Piezometric-contour map of the Floridan aquifer in northwest Polk
County (June 1956) -....--.......------...... ----------..--------- 98
22 Piezometric-contour map of the Floridan aquifer in Lake Parker
area (October 1959 to February 1960) ..............----..-..-........--.... 99
23 Hydrographs of fluctuations of piezometric surface in a well near
Lakeland (759-158-1) and a well near Davenport (810-136-1) in
the Floridan aquifer ......---------.....--............. -.. ..-------------- -----....... ......--- 101
24 Map of peninsular Florida showing the piezometric surface of the
Floridan aquifer in 1944 .....-----.....................----------.... ---------.. 123
25 Piezometric-contour map of the Floridan aquifer at Lakeland (No-
vember 20, 1959) -------... ----..................----.............------ 128
26 Map showing hardness of water in selected wells in the Floridan
aquifer ................-------------------------.... ------------------ 132






27 Map showing water temperatures in selected wells in the Floridan
aquifer ....-------.-----------..--. --------..- ...-..................--............ 134
28 Graph showing total annual municipal pumpage by City of Lake-
land, 1928-59 .. -...................................................................................- 117
29 Log of sediments penetrated in test hole 805-156-A, in Lake Parker. 144
30 Hydographs of water levels in Lake Parker and in wells 803-
154-10 and 806-154-1, 1954-56 .................................... ...... .............. ... 145
31 Hydrographs of water levels in Lake Parker and in wells 805-155-1,
2, and 3, 1956-59 .......-.......-- .-.. ----...... .... ................. .............-...- 146
32 Hydrographs of water levels in Lake Parker and in wells 805-
155-1, 2, and 3, during 1958 .. .-........ .. ................--.................... 147
33 Hydrographs of water levels in Scott Lake and in wells 758-156-5,
757-155-3, and 757-155-6, 1954-60 ..... ...... ........ ....-.......-....... ........-... 154
34 Hydrographs of water levels in wells in the nonartesian aquifer in
the Scott Lake area ...--. --........- ..-- ......--- ....-- ......--- ...-....--....-------- 155
35 Map showing water levels and other features of the Scott Lake
area, July 1956 .........-------- ........---------.....--......---......---- ...---- .....-- 156
36 Map showing water levels and other features of the Scott Lake
area, October 1959-February 1960 .......-.......----....-..-............------- -- ... 157



TABLES
Table
1 Mean monthly temperature and rainfall at Lakeland, Florida for
period 1915 to 1959 .......------ --.. ....-.................- ..... .. ..... .----- 12
2 Total annual rainfall at U.S. Weather Bureau stations in Polk
County, 1954-59 ......................................................---...-...... .....----........... 12
3 Geologic data from wells in Polk County .. .... -----....................-..-- 16
4 Solutional features penetrated by wells in Polk County ...............-..-- 54
5 Records of the occurrence of recent sinkholes in Polk County .......... 67
6 Annual runoff by drainage basins, 1954-59 -...-....--... ....-----.............. 71
7 Water levels observed during drilling operations ..........--.....-- ...-..-.-- 92
8 Net change in water levels in wells in the Floridan aquifer, 1934-59 103
9 Specific capacities of selected wells in Polk County ---..--..-.......-..-.. 104
10 Specific capacities of wells in Polk County ..........---------...... .............. 106
11 Hydrologic properties of limestone core samples from well 805-
154-8 ............ ...--- -- .......... ..- .. -.....-..----- ......-.... 113
12 Range of concentration of chemical constituents in waters of Polk
County _.0............ -.. _.. .. ................................. 1
13 Annual metered pumpage by municipal systems in Polk County,
1954-59 -...--.. --...............----------- -...-..- -..--.....-...--...- .....--........-- ........-------- 1 6
14 Stream-flow measurements in the vicinity of Lake Parker and Sad-
dle Creek .................---- -..--...-. -- --------- --...........--...........-..-.. 148






GROUND-WATER RESOURCES OF
POLK COUNTY, FLORIDA

By
Herbert G. Stewart, Jr.

ABSTRACT
Polk County, Florida is located approximately in the center of
the Florida peninsula, and is an area which requires large quanti-
ties of water for industry, agriculture, and municipalities. Nearly
all water supplies in the county are obtained from ground-water
sources. Domestic and small irrigation supplies are obtained from
limestones of the Hawthorn Formation of Miocene age, and to a
lesser degree from unconsolidated plastic deposits which range in
age from middle Miocene to Recent. Large water supplies are ob-
tained from the Floridan aquifer which includes limestones
ranging in age from middle Eocene to middle Miocene. Geologic
studies near Lakeland show that the Avon Park Limestone is the
lowest unit of the Floridan aquifer, and that there has been no
circulation of ground water in the underlying formations.
The southern end of the Ocala uplift extends into Polk County
and the highest piezometric levels in the Floridan aquifer occur
in the county. As a result of the Ocala uplift the rocks of the
Floridan aquifer have been highly fractured which has resulted
in solutional development of the limestone and extensive cavern
systems. The fracturing has also permitted the free circulation
of water between all units of the aquifer.
Water recharges the Floridan aquifer principally by down-
ward percolation from surficial sands and through the intervening
units to the Floridan aquifer. Only a few inches of rainfall per
year enters the aquifer as recharge in the county. Water budget
analyses for two lakes near Lakeland, during the first 6 months
of 1956, show that the lakes recharged the underlying limestone
:aquifers. Lake Parker recharged water to the Floridan aquifer at
rate of about 2.5 inches per month and Scott Lake recharged
water to the limestones of the Hawthorn Formation at a rate of
About 5 inches per month. Data suggest that other lakes in the
-ounty may also recharge the aquifers at slow rates.
During 1959, approximately 80 billion gallons of ground water
,ere pumped from the aquifers in the county. During the same
.:ear approximately 120 billion gallons were determined to re-





FLORIDA GEOLOGICAL SURVEY


charge the limestone aquifers within the county. The excess o'
about 40 billion gallons moves through the aquifers into adjacent
counties. The potential availability of ground water in the county
can be increased by using more ground water which in turn
creates increased storage in the aquifers.



INTRODUCTION

PURPOSE AND SCOPE OF INVESTIGATION

The investigation upon which this report is based was begun
in April 1954 by the U.S. Geological Survey in cooperation with
the Florida Geological Survey and the Board of County Commis-
sioners of Polk County. Preparation of the final phases of the
manuscript was effected with the cooperation of the Southwest
Florida Water Management District. The general purpose of the
investigation was to provide basic information to assist in the in-
telligent development of the water resources of Polk County. The
investigation was specifically designed to (1) determine the re-
lationships between some of the lakes in the county and the
ground-water aquifers, including the effects of large withdrawals
of ground water on lake levels; (2) determine the mechanics and
quantities of recharge to the principal ground-water aquifers and
to locate areas in which such recharge is occurring; and (3) de-
termine amounts of water being used and to estimate the total
amount available from the principal aquifers.
This report presents general information on the geology and
hydrology of the county and specific information on two lake
basins located in the northwestern part of the county. The rela-
tionship of the many lakes in this area to the ground-water supply
and the effects of large withdrawals of ground water on both
ground-water and surface-water levels are matters of great in-
terest in the county. The complexity of the hydrology of the area
made it necessary to study the geology in considerable detail.
A preliminary report of the investigation was prepared by the
author (1959) and presented detailed information on specific
problems relative to two lakes near Lakeland.
This report constitutes the final interpretative report of the
investigation. A companion report of basic data was also prepared
(Stewart, 1963) and contains well data, chemical analyses, water-






REPORT OF INVESTIGATION NO. 44


level measurements and lake-stage measurements, and other data
g-athered during the course of the investigation.

PREVIOUS INVESTIGATIONS
Some geologic and hydrologic work has been done in Polk
County as part of regional or statewide investigations. Most of
this work has been done by the U.S. Geological Survey and the
Florida Geological Survey.
Cooke (1945), Vernon (1951), and Parker, Ferguson, Love,
and others (1955) described the general geology of central Florida
and made many references to Polk County. Cole (1941, 1945),
Mansfield (1942), Cathcart and Davidson (1952), Davidson
(1952a, 1952b), Cathcart and others (1953), Carr and Alverson
(1953, 1959), Puri (1953b, 1957), Bergendahl (1956), Cathcart
and McGreevy (1959), Ketner and McGreevy (1959), Altschuler,
Clark, and Young (1958), and Altschuler and Young (1960) dis-
cussed the geology of one or more of the formations which are
present in the county. Fenneman (1938), Cooke (1939), MacNeil
(1950), and White (1958) discussed the topographic features of
central Florida, and their origin and development.
Sellards (1908), Sellards and Gunter (1913, p. 262-264), Mat-
son and Sanford (1913, p. 388-390), and Gunter and Ponton
(1931) prepared early discussions and data concerning ground
water in Polk and other counties of central Florida. Stringfield
(1935, 1936, p. 148, 172-173, 186) investigated ground water in
the Florida peninsula and presented data from Polk County. An
important result of his investigation was a piezometric map of
the principal artesian aquifer of peninsular Florida (the Floridan
aquifer in this report) which shows areas of recharge to and dis-
charge from the aquifer in Polk County. The map was expanded
to include most of northwestern Florida and part of southern
(eorgia by the work of M. A. Warren, V. T. Stringfield, and
F. Westendick', and was shown by Cooper (1944, fig. 2), Warren
(1944, fig. 3), and Unklesbay (1944, fig. 5). Cooper (1944),
Stringfield and Cooper (1951a), and Cooper, Kenner, and Brown
(1953) discussed the ground water of Florida and referred to re-
t charge of the principal artesian aquifer in Polk County. Papers by
3'erguson, Lingham, Love, and Vernon (1947), and Stringfield
and Cooper (1951b) described the geologic and hydrologic fea-
1 Oral communication, H. H. Cooper, Jr., U.S. Geological Survey, May 4,
:961.






FLORIDA GEOLOGICAL SURVEY


tures of springs in Florida and presented flow measurements and
other data for some springs. Peek (1951) discussed the cessation
of flow of Kissengen Spring in Polk County.
Collins and Howard (1928), Black and Brown (1951), and
Wander and Reitz (1951) discussed the chemical quality of ground
and surface water in Polk County and other parts of Florida, and
presented many analyses.

METHODS OF INVESTIGATION
Field work began May 1, 1954 with an inventory of water
supplies in the northwestern part of the county. Later the inven-
tory was extended to include the remainder of the county. Infor-
mation on the depth, depth and diameter of casing, water level,
yield, type of pump, use, and quality of the water was obtained
for more than 1,300 wells.
During the inventory, specific wells were selected for the ob-
servation of water-level fluctuations. Water levels were measured
periodically in most of the observation wells, however, continuous
water-level recording instruments were installed on 13 of them.
The levels of several lakes in the northwestern part of the county
also were measured periodically and recording gages were in-
stalled on Lake Parker and Scott Lake, in the Lakeland area.
Current-meter and temperature logs were obtained from 12
wells in the county.
Samples of water were collected from wells and surface sources
for chemical analysis. Composite water samples were collected
from wells being pumped. Water samples were also collected from
bailers, both during drilling operations and after completion of
wells.
Consolidated rocks were found exposed at land surface in small
areas of extreme northwestern Polk and adjacent counties. These
out-crops were examined, mapped, and samples collected in recon-
naissance with Mr. E. W. Bishop, Florida Geological Survey. Dur-
ing mining operations the phosphatic limestones of the Hawthorn
Formation were briefly exposed in the bottoms of some of th,
mine pits in the Lakeland area, and these were studied and de-
scribed whenever possible. Unconsolidated deposits, below the
loose surficial sands, were found exposed in road-cuts, borrow-piti
in the ridge areas along the newer highways, and in phosphate
mine pits and these deposits were briefly studied and described.
Studies of rock cuttings were made during well-drilling opera-






REPORT OF INVESTIGATION No. 44


tin s. Samples from about 250 wells in Polk County are presently
flied at the Florida Geological Survey, most of which were col-
lected and donated by the local well drillers. Cuttings from 25
deep wells, 14 shallow wells, and 4 test holes were collected and
examined during the investigation. Eleven other sets of samples
from wells in the county were collected and logged by other geol-
ogists of the State and Federal Surveys. Most of these wells were
drilled by the cable-tool method. A few wells were started and the
casing installed by the rotary method, and the open-hole portions
of the wells completed and samples collected by the cable-tool
method.
Two deep exploratory wells drilled near Lakeland by private
industry during 1959-60 made an important contribution to
geologic and hydrologic knowledge in this county. The first well,
805-154-8, five miles northeast of Lakeland, was continuously
cored from 58 feet below land surface to a total depth of 1,479
feet with more than 95 percent core recovery. The second, 801-200-
3, three miles southwest of Lakeland, was cored from near the top
of the thick dolomite interval of the Avon Park Limestone (652
feet below land surface) to a total depth of 1,846 feet. The forma-
tions penetrated by the wells include formations deeper than those
normally penetrated by water wells in the county.
The cores from these two wells provide the most complete and
accurate record obtainable from Polk County of the rock forma-
tions penetrated and together with the electric and gamma-ray
logs from the two wells, are used as basic control for all geologic
studies in this report. Rock cuttings and electric logs from other
wells studied during this investigation are used as second-order
control; other sets of well samples and electric logs in the files of
the Florida Geological Survey are used as third-order control;
electric logs of wells from which no samples are available are
used as fourth-order control.
Additional geologic information was obtained from 65 electric
logs of wells made with a single-electrode logger and from 61
gamma-ray logs. For geologic correlation 29 electric logs and 30
gimma-ray logs were made in wells from which rock cuttings
w ;re available for study. The electric logs served as the basis for
m ich of the interpretation of geologic structure in this report. The
gi mma-ray logs were less useful as a geologic tool, but served as an
ai xillary source of data with reference to pebble-phosphate de-
P: sits and the Miocene limestones. Drillers and well owners have
a' o given to the State or Federal Geological Surveys 146 descrip-






6 FLORIDA GEOLOGICAL SURVEY

tive logs of wells from which cuttings were not collected. These
descriptive logs have been of value in the interpretation of ground-
water conditions, general lithology, and geologic structure.


WELL-NUMBERING SYSTEM

The well-numbering system used in this report is based on
latitude and longitude coordinates. Figure 1 shows the well-
numbering system used in this investigation. The well number was
assigned by first locating each well on a map that is divided into
1-minute quadrangles of latitude and longitude, then numbering
each well in a quadrangle in the order of inventory. The well num-
ber is a composite of three numbers separated by hyphens: The
first number is composed of the last digit of the degree and the

Cet ot "gvuel *,l#% of the Green l. CEngfonl, prim mrito.an



,, E 0-I- ..--- -

\4 IV,.. ....










3110 f. o, r

.. .... H . .



Min. ,n l i..lt udTf l l0 t o.lh I'l.

:W:. -- !... Ml--.. .,E H i We s -
\____ I.3.



Figure 1. Map of Florida showing the location of Polk County and the
well-numbering system.






REPORT OF INVESTIGATION NO. 44


t\ -o digits of the minute of the line of latitude on the south side
of a 1-minute quadrangle; the second number is composed of the
last digit of the degree and the two digits of the minute of the line
of longitude on the east side of a 1-minute quadrangle; and the
third number gives the order in which the well was inventoried in
the quadrangle. For example, well 826-131-3 is the third well in-
ventoried in the 1-minute quadrangle north of 28026' north lati-
tude and west of 810311 west longitude. By means of this system,
wells referred to by number in the text can be located on the vari-
ous plates and illustrations of this report.
The same system is used in numbering test holes, exposed sec-
tions, sampling stations, and points of various observations that
were collected or described, except that consecutive letters of the
alphabet are used instead of consecutive numbers. For example,
805-156-A was a test hole. The test holes were filled and aban-
doned immediately after drilling, and therefore are distinguished
from wells.



ACKNOWLEDGMENTS
The investigation was greatly facilitated by the interest, co-
operation, and assistance of city, county, and industrial officials,
residents, and landowners. Well drillers in the area have repeat-
edly made their time, experience, and records available to the
author. Appreciation is here expressed to all of these people.
Grateful acknowledgment is here made to E. W. Bishop, geolo-
gist, Florida Geological Survey, and F. W. Meyer, geophysicist,
U.S. Geological Survey, for the many beneficial discussions and
the exchange of ideas and concepts during the investigation.


GEOGRAPHY
LOCATION
Polk County comprises an area of about 1,860 square miles in
t! e central part of peninsular Florida. (See figure 2.) The county
'.as established February 8, 1861, by separation from what was
t! en Hillsborough County. Hetherington (1928, p. 14) records an
a count of Mr. B. F. Blount that indicates that the population in
C Atober 1851, of what is now Polk County, totaled about 20 fami-





FLORIDA GEOLOGICAL SURVEY


Figure 2. Topographic map showing major physiographic features.

lies, a garrison of soldiers, and some Seminole Indians. Since that
time the population has increased steadily.
The following population figures for the county were taken
from published reports of the U.S. Bureau of Census:
1890 7,905
1900 12,472
1910 24,148
1920 38,661
1930 72,291
1940 86,665
1950 123,997
1960 195,139
The population is concentrated in the cities and towns along the
ridges in the interior of the county. Several hundred square miles
in the northern part of the county and much of the area east cf
the Lake Wales ridge is sparsely populated. The southern part cf
the county is also sparsely populated. Generally, these areas are






REPORT OF INVESTIGATION No. 44


poorly-drained grasslands and flatwoods, relatively low and flat,
and are largely devoted to cattle ranching. During the period of
this investigation many isolated, well-drained hills and low ridges
within the northern and southern areas were cleared and citrus
trees were planted.
The three major ridges and much of the well-drained inter-
ridge areas are devoted to citrus groves. Numerous small truck-
farms are also found in the inter-ridge areas. Vast areas in the
southwestern part of the county have been mined for pebble-
phosphate. Much of the mined-out area has not been improved and
now stands as rugged spoil piles.

TOPOGRAPHY
Polk County is part of the Central Highlands physiographic
division of Cooke (1939, p. 14, fig. 3), the Limesink and Lake Re-
gions of the Floridan Section of the Atlantic Coastal Plain prov-
ince of Fenneman (1938, p. 46-65, and the Atlantic Coastal Plain-
ground-water province of Meinzer (1923a, p. 309-314).
The county is part of the highland area that trends along the
longitudinal axis of the Florida peninsula. The major topographic
features of the county are three long, irregular, north-south trend-
ing ridges which are separated and bounded by relatively flat low-
land. These and other topographic features are shown in figure 2.
The easternmost of the ridges extends from the common corner of
Polk, Osceola, Orange, and Lake Counties approximately south
through Haines City, Lake Wales, and Frostproof, and into the
southern part of Highlands County. MacNeil (1950, p. 101) has
referred to the eastern ridge as the Lake Wales ridge, and White
(1958, p. 10) also uses this name. This is the highest, longest, and
narrowest of the three ridges in the county. Altitudes on the crest
of the ridge range from 150 to 305 feet above msl (mean sea level)
and are highest at Lake Wales and Babson Park.
The central, or Winter Haven ridge (White, op. cit.), begins
abruptly at Polk City, and continues south-southeastward through
Auburndale and along the east side of the Peace River valley to
F'. Meade. It appears to merge with the Lake Wales ridge about
4 miles southwest of Frostproof. This ridge is actually a zone of
snall ridge-remnants approximately 8 miles wide. Between Bar-
tc w and Ft. Meade this ridge becomes a much more massive unit,
b oader and higher than the northern unit. Altitudes along the
c est of the northern unit range from 150 to 200 feet msl, and






FLORIDA GEOLOGICAL SURVEY


much of the southern unit ranges from 200 to 230 feet msl.
The westernmost ridge, or the Lakeland ridge (White, 19.58,
op. cit.), begins abruptly about 10 miles northwest of Lakeland
and extends south-southeastward through Lakeland and between
Bartow and Mulberry, to the vicinity of Ft. Meade. Altitudes along
the crest of the ridge range from 150 to 270 feet msl, and much
of it lies above 200 feet msl. The Lakeland ridge is more continu-
ous and narrow than the Winter Haven ridge. The Lakeland and
Winter Haven ridges appear to trend slightly more north-west-
southeast than the Lake Wales ridge.
All of the ridges are being lowered and dissected by sinkholes.
The Lake Wales ridge has been transected by sinks in the Frost-
proof area, and many other saddles in the ridge are approaching
complete transaction.
The northern part of the Winter Haven ridge has been thor-
oughly dissected by sinks. However, the massive southern unit re-
tains a relatively juvenile linearity on the western flank, and is
being slowly dissected on the lower parts of the eastern flank.
Transection of the two units of this ridge has been complete in a
broad area along Florida Highway 60, north of Alturas. The Lake-
land ridge is being dissected much more slowly than the other two,
though large non-lake sinks appear to be more numerous in this
ridge than in the others.
The northern part of the county, west of the Lake Wales ridge
and north of the other two ridges, is a broad poorly-drained flat-
land that slopes northwestward from about 140 feet msl to about
90 feet msl. It is an area of pine flatwoods, cypress swamps (called
domes), and intervening grasslands.
On the eastern flank of the Lake Wales ridge there are two
large areas of dune-covered terraces and sand hills, one located
southeast of the city of Lake Wales and another north of Daven-
port. East of these is the broad, slightly rolling to flat, marshy
lowland of the Kissimmee River.
Another broad, flat to rolling, lowland exists across the south-
ern part of the county, west of the Lake Wales ridge and south of
the other ridges. Much of this area is poorly-drained pine flat-
woods. The interridge areas are partly rolling lower land, aid
partly low flatwoods and marshes.
Maximum local topographic relief in the county is 219 feet in
the Lake Lenore basin, southeast of Babson Park. Total relief in
the county is 255 feet (from 50 to 305 feet msl).
Surface drainage is poorly developed in the county. On the fl&t-






REPORT OF INVESTIGATION NO. 44


lands there are hundreds of perennial and ephemeral swamps and
basins of interior drainage. In the ridge areas, basins of interior
drainage are even greater in number, depth, and diameter than on
the lower flatlands. In both types of topography some of the basins
of interior drainage (sinkholes) contain lakes.

CLIMATE
All climatic data used in this report are taken from the pub-
lished records of the U.S. Weather Bureau. The data from the
Lakeland station are believed to be generally representative of the
county.
The area has a humid subtropical climate and only two pro-
nounced seasons-winter and summer. The average annual tem-
perature is 720F, and the average monthly temperatures range
from 620F in December and January to 82F in August. The av-
erage annual rainfall is 51.43 inches, about three-fifths of which
occurs from June through September. Most of the rainfall comes
from thunderstorms, which average about a hundred per year.
Total annual rainfall at Lakeland, for the period of record, is
shown graphically in figure 3. The mean monthly temperature and
rainfall through 1959 are shown in table 1.
Total annual rainfall at the Weather Bureau stations in the
county during the period of this investigation is given in table 2.


Figure 3. Graph showing total annual rainfall at Lakeland, 1915-59.






FLORIDA GEOLOGICAL SURVEY


It is to be noted that the rainfall at Lakeland, Bartow, and Lake
Alfred Experiment Stations in 1959 established record highs for
these stations. The Mountain Lake station lacked 31/2 inches that
year of equaling its record high. The second lowest rainfall of rec-
ord for Lakeland (36.30 inches) occurred in 1954, and the lowest
rainfall of record at Lake Alfred in 1955. Table 2 clearly indicates
the great difference in local precipitation in this area. The differ-
ence between highest and lowest total annual rainfall for the sta-
tions shown exceeded 20 inches in 1957 and 1958.


TABLE 1. Mean monthly temperature and rainfall at
period 1915 to 1959.


Lakeland, Florida', for


Temperature Rainfall
Month (OF) (inches)
January 62.4 2.21
February 03.0 2.47
March 67.3 3.69
April 72.0 3.24
May 77.0 4.43
June 80.4 7.38
July 81.6 8.02
August 82.0 7.30
September 80.3 6.42
October 74.7 2.88
November 67.2 1.72
December 63.0 1.97
Annual 72.7 51.79

I U.S. Weather Bureau. Local Climatological Data with comparative data,
Lakcland, Florida for period 1915 to 1959.


TABLE 2. Total annual rainfall at U.S. Weather Bureau stations in
Polk County, 1954-59.

Mean
Station 1954 1955 1956 1957 1958 1959 annual'
Bartow 51.19 41.41 46.34 73.72 01.82 83.44 -54.12
Lake Alfred Exper. Sta. 38.27 35.60 44.40 57.99 40.89 e76.57 51.47
Lakeland 36.30 44.08 45.12 02.38 41.74 70.24 51.43
Mountain Lake (at Lake Wales) 46.05 43.98 41.35 58.21 55.09 71.42 52.70
Winter Hav,,n 38.68 38.78 44.55 66.07 52.73 73.28
Babson Park 36.54 51.14 57.50 66.97 s

1 U.S. Weather Bureau, "Climatological Data-Florida-Annual Summary" 1954 through 1959
s Not computed-less than 20 years record available
a From U.S. Weather Bureau long-term records
e estimated


TRANSPORTATION

The principal highways in the county are U.S. Highways 9:,
27, and 17, which are north-south routes, and U.S. Highway 92
and Florida Highway 60, which are east-west routes. These aie






REPORT OF INVESTIGATION NO. 44


augmented by a network of additional state and county roads.
However, in the less populated northern and eastern parts of the
county there are only a few graded roads.
Most of the towns and cities of the county are served by main
lines of the Seaboard Air Line or Atlantic Coast Line Railroads.
In general, the area is poorly served by direct air service; only
Lakeland has regularly scheduled flights.

AGRICULTURE
Various types of agriculture play an important part in the
economy of the area, and many are important water users. The
most important type of agriculture is the growing of citrus fruits,
principally oranges and grapefruit. Cattle ranching is also an im-
portant part of agriculture. Truck-farming, lumber, and other ag-
ricultural pursuits are of less importance in the economy of the
county.
In the 1954 Agricultural Census (U.S. Bur. Census, 1957, p.
149), Polk County ranked first in the State in the production of
citrus fruits, having 8,012,894 orange, grapefruit, and lemon trees.
The county is also a leader in the production of the less common
citrus fruits, such as limes, tangeloes, and kumquats. Normally, the
citrus groves are irrigated one or more times a year as required.
Locally the growing and marketing of truck-farm crops such
as strawberries, peppers, beans, squash, and other vegetables is
important. The truck farms are relatively small, and normally sev-
eral different crops are grown in rotation during a single year.
These crops are generally irrigated heavily and often.
In 1954 Polk County ranked first in the State in the produc-
tion of cattle (U.S. Bur. Census, 1957, p. 107) with a total of
121,773 head. Ranches are usually large, and are located on the
flatlands in the peripheral areas of the county.

MINERAL RESOURCES
At present eight companies are actively engaged in open-pit
mining of pebble-phosphate in the county. Production in 1959 to-
taled 10.2 million long tons of phosphtae rock2. The mining process
ut lizes large quantities of water; however, extensive storage, set-
tliig, and recirculation practices reduce the amount withdrawn
SPersonal communication, Mr. E. W. Bishop, Florida Geological Survey,
November 7, 1960.





FLORIDA GEOLOGICAL SURVEY


from ground-water aquifers.
More than ten companies were mining (dredging) silica sand
from the unconsolidated deposits in the county in 1960. Five of
these companies are located in the Lake Wales ridge, where the
thickest deposits are found. Other companies were operating in or
near Mulberry, Bartow, Ft. Meade, Waverly, and Winter Haven.
Sand and gravel production totaled 3.3 million short tons in 1959
(U.S. Bur. Mines, 1959, table 5). Most of the water used in this
production is readily obtained from the excavations, and does not
represent significant industrial consumption of ground-water sup-
plies.
Limestone has not been mined in the county due to the thick-
ness of the unconsolidated overburden, low purity of the upper-
most limestone in some areas, and high ground-water levels. How-
ever, a relatively large, previously unmapped area of silicified
limestone, cropping out in the northwestern part of Polk County
and southern parts of adjacent counties, which may become im-
portant to the economy of the county, is discussed later in this
report. Silica replacement of the limestone surface and artesian
ground-water conditions present problems in the newly mapped
area, but an economic potential is clearly present. In 1960, agricul-
tural limestone was being obtained from the Ocala-Brooksville area
to the north or from western Manatee County to the southwest.

INDUSTRY
One of the major industries in the county is the packing, can-
ning. and concentrating of citrus fruits and juices. Another, and
less prominent, allied industry is the production of cattle feed from
the peelings of citrus fruit. Juice concentrate plants are among,
the large consumers of ground water in the county.
The refining of pebble-phosphate and the preparation of com-
mercial fertilizers is a very large and important industry of the
area. Polk County ranks first in the State in the production of
both the refined triple-super phosphate and fertilizers. These
plants use very large quantities of ground water.

GEOLOGY
STRATIGRAPHY
A knowledge of the geology of the rock formations is essential
in the evaluation of aquifers as sources of water. The texture ant






REPORT OF INVESTIGATION NO. 44


S,)mposition of the rocks affect the chemical composition of the
\ater contained and the rate of ground-water movement through
tnem. The thickness, areal extent, and fracturing of the various
rocks will also influence the rate of ground-water movement and
yield of wells. Structural deformation and chemical alteration also
affect the rate of movement through individual rock units and be-
tween units.
Vernon (1951), Cooke (1945), and many others have described
the rock units present in Polk County, their general relationships
and geologic history, the origin of the different unit names, and
the criteria for their identification. However, there has been no
previous work which describes the geology of the county in suffi-
cient detail to understand the hydrology of the rock units.
The areal extent of the various units has not been previously
established. The literature notes cavernous limestone in central
Florida but does not detail the occurrence nor adequately consider
the origin of these solution features which are so important to
ground-water movement. The work of Vernon (1951, pi. 2) sug-
gests the presence of extensive fracturing in the rocks of Polk
County which would also greatly influence the hydrology. The
existing literature does not define the thickness or depth of rocks
which contain fresh water. Thus, a considerable part of this in-
vestigation was devoted to geologic studies that were aimed at
providing more detailed information on hydrology.
All of the consolidated rocks of the county that are normally
penetrated by water wells are limestones or dolomitized limestones.
Over most of the county these are buried by phosphatic clays
which are in turn covered by a blanket of sand that constitutes
the surficial material. Consolidated rocks crop out in a few, rela-
tively small, areas in the northern part of the county. Most of the
geologic information for this report was obtained from rock cut-
tings taken from wells and by the interpretation of electric and
gamma-ray logs of wells. Figure 4 shows the location of wells in
Polk County.
Table 3 shows the depths to the tops of the various geologic
'ormations as determined during this investigation. Table 3 does
lot include a summary of open-file geologic logs of wells by the
*'lorida Geological Survey and which were used in the present
tudy. In the following paragraphs the rock formations penetrated
>y wells in this county are discussed from oldest to youngest.
The stratigraphic nomenclature used in this report conforms
o the usage of the Florida Geological Survey. It conforms also to








TABLE 3, Geologic data from wells in Polk County
Approximate depth to top of each formation given in feet Data source: D, driller's log; G, gamma-ray log;
below land surface: a, absent; c, cased off; e, estimated. S, samples; X, electric log.

APPROXIMATE DEPTH TO TOP OF FORMATION
FOS Hawthorn Ocala Group
USG8 well Altitude Formation Avon
well number of land (Uu.aotone Tamrp Suwannee Cry tal Park
number (W.) aurfaoe only) Formation Limestone River Williton Inglis Limetone Data ource Remarks


74210-2 ...
744.131-1
744-167-1 8852
746-184-1 6351

746-18-1 2304
745-168- ....
745-159-2
747-114-1 1726
747-132-1 4988
747.148-1 1062
747-1583 .
748-119-2 4288
749-149-1
751-156-3 4185
752-150-1 ....
752-150-2 3802
752-10-4 2431
753-128-1 4381


4190



-2765
2742

1441


4255
4684
4902


93
98
148
el85

103
187
e160
e61
202
115
180
100
120
173
e125
123
133
136

110
121
124
101
120
218
216
1l09
264
117
128
265
266
258
140


a
202
c219
140

50
o
112
185
250
@90
58
AB
c250
e52
085
05,
125
80
220


c!


o 382
282
o300 230
aT 230


230
a
250
a
a
e140
220
a
190
125

a?


,X
D, X
8


*275
@394
a
320
c198
277
a
210
245
205

240


5007
027

455
495
590
474
405


360T


1a a 190 210 300 350
92 124 a 146 309 333
o c l155 256 370 395
S c c236 250 382 407
o40 64 120 248 368 392
120 250 300 435 545 610
85 250 300
29 72 80
250 293 323 370 541 582
a a c55 203 824 330
c c 150 250 ...
150
S a c c c c519
140 200 290 425 565? 590
60 a 155 250? ...


630 D, 8
717 X
X
380 D, G..X
320 S X
010 D X
G X
524 G, X
5807 D S
X
...D. S
D. B
5207 8

440 D. 8
G, X
429 X
464 G, X
450 G, X
005 D, 8
D, S
X
658 X
375 D, G, X
G, X
G, X
6507 DD,
... D, S


el37 110 a 140 230 330 380 400 D, S


P-51
Tampa clay not presented
ln samples; no driller's log
available.










Tampa not evident in sam

Tamp not evident in samples
or riller's log.


FGS Wgi-714

P-67
Lare intervals between sam-
Tampa clay not evident in
samples or driller's log
do.


753-129-2
753-139-1
753-152-1
758-168-3
754-181-4
754-155-2
754-158-3
155-151-3
750-134-2.
757-162-1
757-153-2
757-155-
787-18-6
757-155-7
758-146-1
7b9-144-2


---





759-158-1
759-201-I
800-138-1
800-142-1
800-143-2
800-146-1
800-153-1
800-153-3
800-154-3
800-154-6
800-159-1
801438-2
801-143-1
80114544
801-154-8


O632
455i
864
3200
724
4775
8420
4493

4253


801-200-3 f2 core



802-139-2 5098
802-143-3 3307
802-144-2 5443
802-146-2 3851


802-149-4
802-150-3
802-151-10
802-151-19
802-152-10
802-157-16
802-200-1
803-137-1

803-145-2
803-148-6
808-148-7
803-151-11
808-153-3
80$8-153
803-153-24


83633


3422




2925
4050
4215
3772

3425


150
132
123
147
165
152
127
119
e124
el40
146
128
151
147
148


c75
118
132
190?
a
89
c95
120
100
96
go
101
a?


e140
103
a
147
200
155
127
c110
136
130
106
180i
128
170?


C
222
123
a

260
246
217



191
270?


e135 18 83 129 214


120
145
el68
152


130
119
111
Ill
113
110
191
136
164
el13
155
133
141
113
128
127
124


c318
314
183

s..
369
362



313


S a 14 170 ... 270
145 a 190 ... ...
105 290? 350 398
140 125 150 ... ...


05
.34
40
66
24
081
a
155
140
72
80
80?
44
c55
c42
60


110
89
63
75
c154
90
a
a?

a.
120
76
82
68
a?


143
125
82
88
c185
102
a
160


130
98
110
106
107


2437
188


240
200
230

2607
190
232
,. --


~Y, ,Y ....


400
380
392



352
.o


DG, X
D. G, S. X
D. S
S
G, X
D, X
G, X
D, S
8.


Contanidnated eamr les.
Not charaoteristio--may be
absent.


380? 400? 450 D, S Very large sample interval.
Each formation top may be
higher than shown. Tampa
not evident in samples or
driller's log.
e390 e440 D, G, 8, X Loss of circulation and col-
lapse of hole prevented
sampling and electric log:
Lake City 1198 Oldsmar
1588.


4287
326

444
310


563?



5i7


D, 8
8D, S


D, S
G, X
X

D,
D, S
D, 8
D S


D, 8
D, G, S
G, X
X
D, 8


Tampa clay not evident in
samples or driller's log.
1st sample 290
Tampa clay not evident in
samples; shown on driller's
log.
Large sample interval.




Large sample intervals.
Tampa clay not evident in
samples-no driller's log.





Tampa not clearly evident
in samples, may be 10'.


-~s --- Oy~- -~--I -- L --r L ~- --- ~- --- I ~ = -


--


4ou U; rn rnapm noWrMay el- .n.
from driller's log or sam-
a Xplos.
31 _G, X o-4


1rn








TABLE 3 (Continued) a


APPROXIMATE DF.PTH TO TOP OF FORMATION.
Fo8 frwthom Oeala Group
U8Ga wet Altitude Formation Aron
well number o land (lir etone Tamps Suwnaee Crysta Park
number (W-) surface only) Formation Lmestone River Willton Inlle Limestone Datasouree Remarks


M3-153-28 3424 127

80-14-34 5444 136
803-154-85 524 el41
80-1B6-11 3773 147
804-138-1 1733 131
80 L138-2 5338 el33
g80-143-1 4412 e133
804-151-6 .... 129
804-I52-2 3707 118
804-153-4 3770 110
801-154-17 3764 148
" 80-2001 3838 157
806-152 3841 131
80-1548 t core el30
805-155-2 3765 135
S06-155-3 3765 135
805-156-2 3769 136
805-157-16 .... 165
805-159-1 2312 207
806-137-2 3207 178
806-137- 3799 145
806-188-2 8876 132
806-140-1 1753 133
806-142-1 1731 139
806-1496 3768 163
80-155- .3423 140
806-16-2 3771 136
80-158-7 53 e210
807-154-2 3763 136
807-154 3836 134
8W-154-4 3883 135
807-201-1 2774 142
808--151 3837 137
808-155-1 .... 138
808-201-1 4254 152
809-135-1 2869 125


48 86? 112


*82
115
&
a


-84


9-1


68


140
a
a

a
a
115
67?
a
a

a


c452




430
366
367


400


... ..,S


D, S

S

S
G, X
D. 8
D, 0, S
D, S
D, S. X
D, G, S, X
D G,. X
D. G. X
D: G, S
x
D, S
D. S
D,S
D
D, S
D, S
D, G, S
G, S
D, G, S
D, S
D, G, S
D, S


GX
D, S
S


Tampa not elearly evident
from samples-no driller'
lo0


Fiut same at
no driller log.


140'-


Top Lake City 1028' top



50 west of W-448







Questionable samples.

Top lake City 1110'.




Sdk-136-2 4&63
809-136-4 2013
809-147-1 4275
809-148-2 5045
809-153-3 3865
810-136-1
810-144-1 4990
810-148-1
810-151-2 ....
810-154-1 3867
810-155-1 3866
811-138-3 4919
812-135-1 46412
813-149-1 5046
818-201-1 5352
814-139-4 5348
814-148-1
815-138-1 4964
815-142-1 2133
815-157-2 3839
816-148-1 4689
818-151-2 .
819-140-1 5016
819-147-1 .
Sumter County:
821-202.3 5054


Pasco County:
816-206-1 550
Hillaborough County:
742-216-1
744-226-10 ...
745-215-1 ...
751-203-1


130
131
135
179
136
113
138
168
152
129
129
175
116
132
105
e150
136
173
143
109
128
124
213
128


a
a
a
elo
a
a
clO@
a
a
c55
230
a
a
17
a
a
a
a
a
a
a
a


244
200.
257
246
166
219
128
c236
260
247

125
220
160
154
90
125
145
126
235
c97


D. G. S, X
D, S
D. S

C, X
X
D, G, X
X

D, X
D, 8
D, G, X
S
D, 8
D. S

D, G, S, X
S
D, S
D, 0, S. X
D. S.
D. G, X
D. S
X


Irreaular san.;ie,.


PF-
Wgi to 65
Brried sinkhole

Tampa clay not indicated ia
samples or driller's log.






Wgi 1077


96 a a 0 72 101 136 D, G, S. X Avon Park top indicated also
by gamma-ray los.


21 40 81) 157 190 D, 8, X


106 e e6 147
0 17 ... 302
145 e155 ... 274
120 c ... 115


e310

460
2M8


Intexpretation by H. 31.
Peek, (1959, fig. 15)






FLORIDA GEOLOGICAL SURVEY


the usage of the U.S. Geological Survey, with the exception of the
Ocala Group and its subdivisions, and the Tampa Formation of
Miocene age. The Florida Geological Survey had adopted the Ocala
Group as described by Puri (1957), but the U.S. Geological Survey
includes these strata in the Ocala Formation and the underlying
upper part (= Inglis Limestone of former usage) of the Avon Park
Limestone. The Tampa Limestone, as used by the U.S. Geological
Survey, is referred to as the Tampa Formation by the Florida
Geological Survey.

EOCENE SERIES
OLDSMAR LIMESTONE
Vernon (1951, p. 87, 92) and Cooke (1945, p. 40, 46) indicate
that the Oldsmar Limestone probably underlies all of peninsular
Florida, and that the thickness of the formation may range from
300 to 1,200 feet. They further indicate that the Oldsmar uncon-
formably underlies the Lake City Limestone.
Four test holes in Polk County penetrate the Oldsmar Lime-
stone. Applin and Applin (1944) examined the samples from well
750-148-1 and placed the 670-feet interval from 1,960 to 2,630 feet
in the Oldsmar. The cores and logs from two deep exploratory
holes drilled near Lakeland furnish much of the geologic informa-
tion used in this and the following sections on stratigraphy. One
core hole, about 3 miles southwest of Lakeland (well number 801-
200-3), was drilled to a depth of 1,842 feet. The other core hole,
about 5 miles northeast of Lakeland (805-154-8), was drilled to a
depth of 1,479 feet. Both of these holes terminated in the Oldsmar
Limestone. The abstracted logs of these two holes are given here
to aid in the discussion.

Core Hole 3 Miles SW of Lakeland (801-200-3)
Altitude of Land Surface is Approximately
135 feet above msl.
DEPTH IN FEET,
MATERIAL BELOW LAND SURFACE
Undifferentiated:
Sand and clay. 0-14
Hawthorn Formation:
Limestone. 14-93
Tampa Formation:
Clay, blue-green. 93-135







REPORT OF INVESTIGATION No. 44


Core Hole 801-200-3-Continued
DEPTH IN FEET,
MATERIAL BELOW LAND SURFACE
Suwannee Limestone (start core at 139 ft.
3 in.): Chert, dark gray, very hard; re-
placed limestone, with pre-chert solutional
cavities up to 2% inches, filled with cream
limestone containing Sorites sp. Drilling
water circulation lost at 138 feet. 135-142%
Unidentified:
Not cored from 142% to 652%; all drilling
water circulation lost, no cuttings re-
turned.
Avon Park Limestone:
Open cavern. 440-445
Sand and mud (driller's interpretation),
probably cavern-fill, very soft. 445-455
Open cavern, casing slipped to bottom of
hole. 540 %-5471%
Casing set by water-jetting only; probably
sand and mud cavern-fill, very soft. 547%-576
Casing set by water-jetting and casing ro-
tation only; probably extensive honeycomb
and/or sand and mud cavern-fill, very soft. 576-653
In Avon Park Limestone (cored from 652 ft.
11 in. to total depth 1,842 ft.) :
Dolomite, replaced limestone, dark brown,
dense, broken and highly fractured (some
re-cemented). (See figure 4.) 653-665
Dolomite, as above, with solution cavities
up to 2% inches, and one open vug (after
gypsum) containing small amounts of
loose brown dolomite sand. Cavities are de-
veloped along fractures in cavern collapse
rubble. 665-670
Dolomite, as above, cavern-fill developed in
dolomitized collapse rubble (fill). 670-673
Dolomite, as above, badly broken to resem-
ble coarse gravel. May include a continua-
tion of pre-dolomite collapse zone above. 673-684
Dolomite, as above, a collapse rubble of
angular dis-oriented inclusions in finer
grained matrix. Cavities developed and
partly filled with brown dolomite sand (?). 684-685%
Dolomite, as above, badly broken in zones. 685%-703
Dip-slip faulting or slumping, and repeti-
tive thin beds due to overriding thrust. 703-






FLORIDA GEOLOGICAL SURVEY


Core Hole 801-200-3-Continued

DEPTH IN FEET,
MATERIAL BELOW LAND SURFACE
Thrust fault cutting a chert nodule. Slick-
lenslides on nearly horizontal bedding-
plane thrust. 703Y8-
Dolomite, as above, locally broken and
fractured. A few small solution cavities de-
veloped (vugs after gypsum?) 703-7221/
Dolomite, as above, a dolomitized rubble.
Angular inclusions up to 1% inches, in
finer grained matrix, have random orien-
tation. Believed of collapse origin, but pos-
sibly a pre-lithification sedimentary rubble. 7221/-725%
Dolomite, as above, badly broken and frac-
tured in some zones. 725%-742%
Dolomite, as above, collapse rubble, angu-
lar inclusions up to 2 inches in heteroge-
nous matrix, with random orientation of
inclusions. 742% -746
Dolomite, as above, massive and dense to
badly broken in zones, occasional solution
cavity up to % inch. 746%-778%
Clay. a sedimentary rubble. 778-780%
Limestone, soft, chalky; some fine to very
fine honeycomb development and occasional
cavities up to 1 inch. 780-875
Limestone, soft to hard in zones, solution tubes
up to '4 inch diameter and fine honeycomb
development. 875-951
Limestone, dolomitic?, hard with fine hon-
eycomb development. 951-1,068
Limestone, moderately soft, with tubes and
cavities up to % inch. 1,068-1,128
Lake City Limestone:
Limestone, soft to hard, chalky zones, low
permeability with occasional fine honey-
comb, abundant nodules and nests of nod-
ules of gypsum altered from anhydrite.
Abundant and general impregnation by
selenite. Some open pore-space and molds,
but not common. 1,128-1,451
Dolomite, replaced limestone, very hard,
general selenite impregnation, but some
open pore spaces, small tubes and cavities,
gypsum nodules altered from anhydrite.
Fractures, vertical to high-angle, in lower
part are re-cemented by selenite. 1,451-1,588






REPORT OF INVESTIGATION NO. 44


Core Hole 801-200-3-Continued
DEPTH IN FEET,
MATERIAL (Con't) BELOW LAND SURFACE
Oldsmar Limestone:
Dolomite, hard, pore space as molds and
fine honeycomb, generally selenite impreg-
nated; gypsum nodules altered from anhy-
drite, some selenite cemented fractures.
Some thin zones of dolomite sand (?). 1,588-1,688
Dolomite, as above, dolomite sand (?)
zones more numerous and thicker with
very high porosity; a few scattered open
vugs after gypsum (?) excavation. Gyp-
sum nodules altered from anhydrite. Sele-
nite impregnation of dense dolomite zones. 1,688-1,746
Dolomite, as above, abundant nests and
scattered gypsum nodules altered from an-
hydrite; selenite as impregnation and frac-
ture cement. 1,746-1,812
Anhydrite, white, massive, single bed. 1,812-1,816
Dolomite, as above, scattered anhydrite and
gypsum nodules, scattered occurrences of
dolomite sand (?), extensive selenite im-
pregnation of massive dolomite, and post-
dolomite fractures. 1,816-1,842

Core Hole 5 Miles NE of Lakeland (805-154-8)
Altitude of land surface is approximately
130 feet above msl.
Undifferentiated:
Sand and clay. 0-50
Hawthorn Formation:
Limestone. 50-58
Tampa Formation:
Clay, blue-green. 58-60
Suwannee Limestone:
Limestone, detrital, very soft, chalky, little
evidence of solutional activity. 60-151
Ocala Group
Crystal River Formation:
Limestone, soft, granular to very chalky,
little evidence of solutional activity. 151-276
V illiston Formation:
Limestone, soft to moderately hard, granu-
lar, local dolomitized zones, some solutional
removal of calcite matrix. 276-286





FLORIDA GEOLOGICAL SURVEY


Core Hole 805-154-8-Continued
DEPTH IN FEET,
BELOW LAND SURFACE
Inglis Formation:
Limestone, granular, soft to hard, locally
dolomitized, note solutional removal of ce-
ment and fossil molds, fine solutional tubes,
and local honeycomb. 286-345%
Avon Park Limestone:
Limestone, hard to soft, granular to
chalky, visible porosity moderate to very
high in granular zones. 346-4441%
Dolomite, replacement of limestone, very
hard and dense; solution tubes 1 inch x 14
inch diameter. (First such features noted.) 444%-449%
Lost drilling water circulation. 512-
Dolomite, replacement of limestone, very
hard; dense to granular, low to very high
visible porosity. 521-615
Lost drilling water circulation. 529-
Fine honeycomb. 534-536
Dense, badly broken, as dolomite
"gravel." 538-542
Dense, thin bedded, with zones of fine
honeycomb. 542-552
Badly broken, as gravel, some solution
along fractures. 552-553
Badly broken, as gravel, in zones. 556-564
Collapse rubble zone; angular inclu-
sions up to 4 in. Random orientation,
one 3 in. piece is thin-bedded with bed-
ing-tipped vertical, matrix fine-grained
and thin bedded. 566-567
Collapse rubble, angular, badly broken. 574%-575
Dense, badly broken. 575-578%
Collapse rubble, very angular inclu-
sions up to 2 in. Random orientation,
yellow thin-bedded inclusion tilted with
bedding at high angle to core. Some sol-
ution along fractures through interval.
This interval may be essentially con-
tinuous from 574%. 578%-588
Dense, badly broken. 597-610%
Limestone, moderately soft, very fine hon-
eycomb developed. 621 -623%
Limestone, soft to moderately hard, some
small tubes and fine honeycomb. At 685
feet first open vug from removal of gyp-
sum alteration of anhydrite nodules. 623%-685






REPORT OF INVESTIGATION NO. 44

Core Hole 805-154-8-Continued


Limestone, collapse rubble, middle 1% foot
dolomitized. Post dolomite fractures.
Collapse rubble continues from 695; core
shows old cavern wall and fine-grained fill
with larger inclusions. Badly broken in
lower part; fine second-stage solution hon-
eycomb developing in dolomite.
Dolomitized collapse rubble with post-
dolomite fractures.
Limestone, generally chalky and soft to
moderately hard in thin local partially dol-
omitized zones. Visible porosity low to
moderate due to fossil molds and fine hon-
eycomb development. Numerous large (to
2%-in.) irregular vugs resulting from so-
lutional excavation of gypsum altered from
rubble of anhydrite nodules. Abundant cal-
cite crystals in vugs below 879 feet, and a
few quartz crystal growths noted. Oc-
casional silicified clay beds a few inches
thick.
Lost drilling water circulation; regained
and partial loss of circulation again at 796
feet.
Limestone, chalky, very soft to moderately
soft, heavy selenite impregnation of pores
and molds. Nodules of gypsum (after an-
hydrite) up to 1% in.
Lake City Limestone (1,028-1,445%):
Limestone, chalky, soft; contains irregular,
rounded, nodules of gypsum altered from
anhydrite rubble. Profuse selenite impreg-
nation of pore space, but some small open
solutional cavities and fossil molds noted.
Visible porosity generally low.
Limestone, dolomitic, with gypsum as above.
Dolomite, replaced limestone, hard, crystal-
line. Gypsum nodules as above, selenite im-
pregnation, and some small open pore
space.
Dolomite, as above, with small cavities con-
taining dolomite-sand fill. Gypsum as
above.
Limestone, dolomitic, moderately soft to
moderately hard, low porosity. Selenite im-
pregnation and gypsum as above. Occa-
sional open vug after gypsum.


DEPTH IN FEET,
BELOW LAND SURFACE

695-698




698-704

716-717











717-1,015%


785-



1,015%-1,028






1,028-1,295%
1,295%-1,374%



1,374%-1,386


1,386-1,392%


1,392%-1,445%


25





FLORIDA GEOLOGICAL SURVEY


Core Hole 805-154-8-Continued
DEPTH IN FEET,
BELOW LAND SURFACE
Oldsmar Limestone (1,445%-1,479):
Limestone, dolomitic, moderately hard.
Small gypsum nodules as above, a few
small vugs after gypsum. Some selenite
impregnation and fine honeycomb. 1,445 -1,459
Dolomite, replaced limestone, dense, hard;
scattered gypsum as above, and some sele-
nite impregnation; fine honeycomb zones
and rare small open vugs after gypsum. 1,459-1,479
On the basis of the major change in character of the electric
and gamma-ray logs, and lithology, the lower 331/L feet (1,4451,X-
1,479 feet) of well 805-154-8 and the lower 258 feet (1,588-1,846
feet) of well 801-200-3 are tentatively designated as Oldsmar
Limestone.
In wells 801-200-3 and 805-154-8, the Oldsmar is a grayish-tan
to brown, very hard, finely crystalline, highly dolomitized, gypsi-
ferous limestone. Generally, dolomitization appears to follow
bedding planes and is inter-bedded with a few soft, calcareous
zones. Color of the formation becomes more grayish downward
with increasing amounts of disseminated peat.
The formation contains rubble-beds which are generally less
than a foot thick, which were formed before the sediments were
firmly cemented and lithified. These are interpreted as bottom
sediments which have been broken up by wave action while in a
semi-plastic state, then re-deposited and cemented. Such changes
may reflect storm waves of greater than normal proportions. The
formation also contains sequences of thin, individual graded-beds,
each bed being only 1 or 2 inches thick. These graded-beds, and the
rubble-beds, indicate rapidly changing sedimentary conditions in
a relatively shallow sea or embayment. Such changes may have
been short-lived and of generally small magnitude. Thick peat a:-
cumulations at the top of the formation were interbedded with
rubble-beds. Other rubble-beds were found throughout the forma-
tion. Further study of such features in these two wells will pro-
vide more information about the environment of deposition of tle
formation.
In wells 801-200-3 and 805-154-8 in the Lakeland area, the con-
tinuous cores from the Oldsmar Limestone contain considerable
amounts of anhydrite, gypsum, and selenite, a clear crystalline
variety of gypsum. A solid bed of anhydrite was encountered from






REPORT OF INVESTIGATION NO. 44


1,, 12 to 1,816 feet in well 801-200-3. With this exception, the
an iydrite and gypsum in the Oldsmar occurred as rounded irreg-
ul;tr nodules that are several inches long in the greatest dimension.
The nodules were not apparently oriented and were scattered as
individual nodules or deposited in clusters that seldom exceeded a
foot in thickness. The nodules were originally anhydrite and all
but a few in the lower part of the formation have been partly or
completely altered to gypsum by varying degrees of hydration.
Most of the gypsum nodules contain a large core of unaltered an-
hydrite. This alteration is accompanied by a 30-50 percent in-
crease in volume (Pettijohn, 1949, p. 356), and the increase was
evidenced by the fracturing and filling of adjacent limestone
stringers and walls. The evaporites usually originate as bedded
deposits in closed shallow basins. The occurrence here as separate
nodules is interpreted as being the rubble of originally bedded de-
posits which have been destroyed by wave action. The size and
shape of the nodules suggest that the rubble was transported a
relatively short distance before re-deposition. Such an interpreta-
tion is consistent with that of the pre-lithification sedimentary
rubble beds mentioned previously. Selenite occurred in much of the
formation as an impregnation of pore spaces and as fracture filling
or cement. The selenite probably represents a further alteration,
or solution and precipitation, of gypsum. Several small nodules of
gypsum have been completely dissolved leaving open vugs in the
rock. These vugs have intricate irregular walls like those enclosing
the nodules cut by the drill, and there can be no doubt as to the
origin of the vugs.
In the core samples from wells 801-200-3 and 805-154-8 the
contact of the Oldsmar with the overlying Lake City Limestone is
indefinite and appears to be a disconformable zone, rather than
an erosional unconformity. The disconformable zone appears to
be about 30 feet thick and contains large quantities of peat or
low-grade lignite. The peat is thought to be of marine origin and
to represent a long period of very shallow water conditions and
li tle deposition. The presence of gypsum and anhydrite nodules in
th;e disconformable zone and subjacent beds of the Oldsmar indi-
c te the absence of fresh water erosion or circulation of fresh
r 'ound water after deposition.
Excellent correlation of the disconformable interval was made
b gamma-ray logs of the two wells, which showed marked in-
c eases in radioactivity in the thick peat zone at the top of the
f rmation. The disconformable zone appears to be unfossiliferous,





FLORIDA GEOLOGICAL SURVEY


but this may be partly due to intense dolomitization and resultant
destruction of fossils. The peat occurs as beds from 6 to 14 inches
thick, as thin seams and bedding-plane films, and as disseminated
flakes. Only a slight change in color and lithology may be noted in
passing downward from the Lake City Limestone into the Oldsmar
Limestone.
In wells 801-200-1 and 805-154-8 the formation has very low
visible porosity and permeability. Both porosity and permeability
seem to increase in fractured dolomitized zones, but some of these
zones have been partially re-cemented or filled with selenite. The
presence of selenite, gypsum, and anhydrite throughout the for.
mation clearly shows that there has never been a significant
amount of fresh ground water in it, because these minerals an
soluble and would have been removed.

LAKE CITY LIMESTONE
The Lake City Limestone is penetrated by relatively few wells
in this county, and only four wells are known to pass entirely
through the formation.
According to Cooke (1945, p. 46), the formation underlies all
but the northwestern part of the state. Samples were not collected
from this formation in well 811-149-1. According to Cooke (1945
p. 48), the Lake City was encountered in well 750-148-1 at a depth
of 1,540 feet, and it extends to a depth of 1,960 feet.
In well 805-154-8 a selenite and peat (?) replacement of
Dictyoconus amcricanus, the index fossil of the Lake City, was
recovered from the core at a depth of 1,0281/ feet. Identification
was based on the internal cell structure as illustrated by Applin
and Jordan (1945, p. 136, fig; 2). Other specimens were observed
in the core at this depth.
The electric log of this well shows a decrease in both resistivity
and self-potential at a depth of 1,028 feet in a moderately soft,
clayey, chalky zone of low visible porosity. The top of the forrni-
tion is therefore placed at 1,028 feet in this well, and the forria-
tion continues to a depth of 1,4451/2 feet. The formation top on
this electric log correlates very closely with the electric log of
nearby well 807-154-4 at a depth of 1,110 feet. This depth (1,.10
feet) also coincides with the first occurrence of chert and gyps m
in the well according to a log prepared by E. W. Bishop of .he
Florida Geological Survey (FGS W-3883, July 17, 1956). BisI op
(op. cit.) designates the interval 1,110-1,198 feet as Avon Pr'k






REPORT OF INVESTIGATION NO. 44


Linestone. In well 801-200-3 the Lake City Limestone is identified
in the interval from 1,198 to 1,588 feet by correlation of electric
and gamma-ray logs with those of well 805-154-8. On the basis of
these three wells, the thickness of the Lake City Limestone ranges
from 4171/ to 420 feet in Polk County.
In wells 801-200-3 and 805-154-8 the Lake City Limestone is a
white to cream, moderately soft to hard, chalky limestone. The
lower 75 to 130 feet of the formation contains finely crystalline,
highly dolomitized zones which appear to follow bedding planes.
'The formation contains abundant peat films on bedding planes.
Scattered chert nodules occur in the upper part of the formation
and few thin apparent chert "beds" in the lower part of the for-
mation may actually be small nodules or lenses. All of the chert
appears to be of secondary origin as a replacement of limey sedi-
ments. Pre-lithification sedimentary rubble-beds, generally a few
inches thick, are abundant throughout the formation in both wells
801-200-3 and 805-154-8.
In wells 801-200-3 and 805-154-8 the Lake City Limestone con-
tains abundant anhydrite, gypsum, and selenite. The nodular
mode of occurrence of these minerals in the Lake City is the same
as that previously described in the Oldsmar Limestone. The same
interpretation of origin and alteration, from original bedded an-
hydrite to nodular gypsum and selenite, also applies to the Lake
City. However, the Lake City in these two wells does not contain
bedded, or unaltered nodules of anhydrite. In general, the anhy-
drite cores of the nodules decrease in size upward and completely
altered nodules of gypsum are common. Individual nodules reach
as much as 12 inches in their greatest dimension. Selenite im-
pregnation of pore spaces, small solutional tubes and cavities,
small vugs, and fractures occur throughout much of the forma-
tion. Open vugs, generally less than 1 inch in diameter, resulting
from solutional removal of anhydrite-gypsum nodules occur
throughout the formation. These are relatively few in number, but
are more numerous than in the Oldsmar.
Cooke (1945, p. 46) and Vernon (1951, p. 92, 99) indicate that
f'e contact of the Lake City and the overlying Avon Park Lime-
s'one may be unconformable. In the cores from wells 801-200-3
I d 805-154-8 the contact zone is not obvious. In well 805-154-8
r. psum nodules occur at 1,038 feet, 10 feet below the contact. In
v ell 801-200-3 gypsum nodules occur throughout the contact zone
; id adjacent beds. The occurrence of gypsum nodules and the con-
t nuity of lithology strongly suggest that the contact is transi-






FLORIDA GEOLOGICAL SURVEY


and their significance will be discussed in more detail in the sec
tion on solutional features.
The Avon Park contains anhydrite-gypsum nodules in the same
mode of occurrence as has been previously described in the Olds-
mar and Lake City Limestones. The same interpretations of origin
and alteration, from original-bedded anhydrite to nodular gypsum
and selenite, stated for these earlier formations is also applied to
the Avon Park. However, in wells 801-200-3 and 805-154-8 the
Avon Park does not contain unaltered anhydrite, and it now con-
tains considerably less total anhydrite, gypsum, and selenite than
the two underlying formations. In well 801-200-3, the cored well
southwest of Lakeland, the Avon Park contained scattered gyp-
sum nodules and clusters and selenite impregnations only in the
lower 70 feet (1,128-1,198). In well 805-154-8, northeast of Lake-
land, the Avon Park contained such deposits only in the lower 13
feet (1.015-1,028). In both wells the gypsum nodules contained
cores of anhydrite.
There is no doubt that the Avon Park once contained a much
greater amount of the evaporate nodules. In well 805-154-8 many
open vugs with irregular, concavely rounded walls, occurred at
depths of 685 to 885 feet. It seems clear that these vugs result
from the complete solutional removal of evaporite nodules. The
open vugs were scattered and sparse in number from 885 to 1,015
feet. Only a few vugs were found in the cores from well 801-200-3
and these occurred from 829 to 1,128 feet.
The Avon Park Limestone contains numerous thin, porous,
granular, sand-like zones of dolomite, the origin of which is un-
known. There are several suggested origins that may be possible:
(1) Some zones may be a depositional dolomite-sand in solutional
cavities; (2) some zones may be an ultra-fine honeycomb de-
veloped along fractures and other openings by solution; and (3)
some of the zones may be the result of precipitation of ultra-fine
dolomite crystals. Such zones are also found in the dolomitized
zones of the underlying Lake City and Oldsmar Limestones.
The formation also contains, particularly in the lower part,
numerous chalky or clayey zones; some thin, well-defined calcare-
ous clay beds; and abundant peat as thin films on bedding planes.
There are also chert nodules, apparent chert beds, and diffused
silicified zones.
Vernon (1951, p. 99) states that both of the formational con-
tacts are erosional unconformities. The present studies of cores
from wells 801-200-3 and 805-154-8 in the Lakeland area, and






REPORT OF INVESTIGATION NO. 44


iany sets of cuttings indicate that the contact in Polk County is
.:nconformable. The lower few feet of the overlying Inglis For-
.ation generally contain pieces of dark, granular rubble up to
1-inch diameter and abundant eroded Dictyoconus sp. and
S'oskinolina sp. from the Avon Park. This is interpreted as
weathered Avon Park Limestone, eroded and re-deposited in the
early stages of Inglis deposition and hence an unconformable con-
tact.
Permeability of the formation ranges from very low in some
of the clayey or chalky zones to extremely high in cavernous
zones. The visible porsity and permeability of the formation, as a
unit, is high and it is the greatest water-producing unit in the
Floridan aquifer in Polk County. Local areas in which the for-
mation as a whole is of low permeability have been encountered,
but these are relatively few in number.
OCALA GROUP
In recent years the Florida Geological Survey has subdivided
the rocks formerly grouped within the Ocala Limestone. Vernon
(1951, p. 113-171) divided this sequence of rocks into the Ocala
Limestone (restricted) and the Moodys Branch Formation. He
divided the Moodys Branch Formation of his usage into two parts.
The lower unit was named the Inglis Member, and the upper unit
was named the Williston Member.
Puri (1953a, 1957) gave the name Crystal River Formation to
Vernon's restricted Ocala Limestone and gave formation rank to
Vernon's Inglis and Williston Members of the Moodys Branch
Formation. The Crystal River, Williston, and Inglis Formations
are now referred to as the Ocala Group by the Florida Geological
Survey and the name Moodys Branch Formation is no longer used
in Florida. The northeastern half of Polk County is underlain by
the Ocala Group as shown in figure 5.

Inglis Formation
The Inglis Formation underlies almost the entire county except
in local areas in northeastern part and is a white to cream to dark
brown, generally hard to very hard, granular, partially to highly
dolomitized, highly fossiliferous limestone with some local soft
chalky zones. In the area lying generally north and west of Polk
City, the formation is highly dolomitized, very hard and contains
many sand-filled solutional cavities.
In the central part of the county the formation has a relatively






FLORIDA GEOLOGICAL SURVEY


uniform thickness of 35-45 feet. In well 821-202-3 in Sumter
County, northwest of Rock Ridge (fig. 4), the Inglis is 29 feet
thick. This well is located along the crest of the major structural
feature in the area. In well 805-154-8, northeast of Lakeland, the
Inglis is approximately 50 feet thick. It thickens slightly along the
extreme western part of the county to about 45-50 feet. In the
southeastern part of the county the Inglis is as much as 95 feet
thick.


Figure 5. Geologic map of the pre-Miocene formations.


The Inglis is the uppermost limestone in extreme north-
eastern Polk County due to erosion of the overlying beds along
the crest of a structural high. The Inglis conformably underlies
the Williston Formation, and unconformably overlies the Avon
Park Limestone. (Vernon, 1951, p. 212).
In well 805-154-8 the Inglis appears to have low to moderate
porosity in the upper part of the formation. Moderate to high
visible porosity in the lower part of the formation is due to the






REPORT OF INVESTIGATION NO. 44


.emoval of the calcite cement and matrix in the granular and
'ossiliferous zones. The Inglis is one of several formations usually
)enetrated by water wells in this area. Locally it may be a good
producer due to cavernous conditions and/or its generally granu-
lar texture. However, wells are not usually drilled for the purpose
of obtaining water from this formation.
Williston Formation
The Williston Formation is a white to cream to brown lime-
stone, and is a generally soft, coarse, coquina of foraminifera,
set in a chalky calcite matrix. The lower 5-15 feet are usually
harder than the rest of the formation due to dolomitization. The
formation has moderate visible porosity. The Williston is gener-
ally less highly dolomitized than the underlying Inglis Formation.
The formation underlies most of the county with a thickness
which ranges from 10 to 100 feet, and averages about 30 feet.
These thicknesses are based principally upon electric-log determi-
nations. In extreme northeastern Polk County the formation is
missing, having been removed by erosion, and may be missing
from other local areas near the crest of the structural high.
Vernon (1951, p. 143) states that the formation lies con-
formably between the Inglis and the overlying Crystal River
Formation. The lower contact is marked by a distinct lithologic
change, but the upper contact is transitional and very difficult to
define.
The Williston is one of several formations usually penetrated
by water wells in this county, and it is believed to contribute some
water to wells. The general character of the formation (soft,
coquinoid, and chalky matrix) results in a lower porosity and
permeability, as compared to the more productive underlying
formations.

Crystal River Formation
In the subsurface the Crystal River Formation is a white,
gray, cream, or tan, generally very soft, coarse, granular, lime-
stone of very high purity which contains great numbers of large
foraminifera in a chalky carbonate matrix. Locally it may contain
thin hard dolomitized beds or zones which are controlled by
bedding.
The Crystal River is easily recognized from the abundance of
disc-shaped foraminifers of the genus Lepidocyclina. In some of
the species the disc has a saddlelike shape. The formation com-





FLORIDA GEOLOGICAL SURVEY


only is referred to as "Ocala," "shell," or "limeshell" by local
drillers.
The formation ranges in thickness from 80 to 125 feet in an
east-west belt across the county between Lakeland and Ft. Meade.
South of this belt it thickens gradually southward to 150 feet,
possibly even thicker locally. North of the belt, it ranges from
30 to 60 feet in thickness due to erosion and has been entirely
removed from broad areas lying northeast of Polk City. The for-
mation has been removed by erosion in the vicinity of eastern
Winter Haven, where the Williston Formation appears to be di-
rectly overlain by the Suwannee Limestone. Both the Crystal
River and Williston have been removed by erosion from the
vicinity of Haines City and the Inglis is directly overlain by the
Suwannee Limestone.
The Crystal River is the uppermost Limestone in the northern
part of the county due to erosion of the overlying Suwannee and
younger formations. Along the crest of the structural high area
in northwestern Polk and adjacent parts of Lake and Sumter
counties, the Crystal River Formation is at, or within a few feet
of the surface over an area of approximately 100 square miles.
This outcrop area has not been previously mapped or described
in any literature. The outcrop area was mapped and studies in a
reconnaissance by E. W. Bishop, geologist, Florida Geological
Survey, and the author in April 1957. The results are discussed
here with the permission of Mr. Bishop."
Throughout the area of surface exposure the limestone is silici-
tied by replacement with hard, dark gray to white chert. In these
exposures the fossil content has been generally destroyed by the
replacement, but locally small concentrations of Lepidocyclina
ocalana were found. Lepidocyclina ocalana is a diagnostic fossil
of the Crystal River and is usually abundant in the formations.
Numerous echinoids were observed in many parts of the out-
crop area. In some locations the echinoids were found adjacent
to occurrences of Lepidocyclina ocalan. More than 40 specimens
of echinoids were collected, and they appear to represent a single
species. Nine of the best specimens from the area of outcrop, and
one from a limestone pit at Lacoochee, Pasco County, were
identified as Rhyncholampas (Cassidulus) gouldii (Bouve) by
Mr. Porter Kier, Associate Curator, Division of Invertebrate
Paleontology and Paleobotany, U.S. National Museum.4 Cassidu-
Personal communication, E. W. Bishop, December 12, 1960.
SPersonal communication, Porter M. Kier, April 10, 1961.






REPORT OF INVESTIGATION NO. 44


?us gouldii (Bouve) is a diagnostic fossil of the Suwannee Lime-
stone of Oligocene age, which normally overlies the Crystal River.
The echinoids are preserved as filled molds, the filling being
.1 miliolid-rich granular limestone. In one such echinoid, a speci-
men of Dictyoconus cookei was found and, although this fora-
minifer is diagnostic of the Avon Park Limestone, it is also fre-
quently found in the Suwannee Limestone.
Because of the observed association of Suwannee and Crystal
River fauna the outcrop area is interpreted as being the eroded
remnant of the original contact zone of the two formations. Such
interpretation thus places the thickness of the Crystal River on
the crest of the Ocala uplift at 60 feet or less. Only one outcrop
of slightly calcareous limestone was observed.
A well in the outcrop area in southern Sumter County, 821-
202-3, penetrated 72 feet of the Crystal River Formation.
Surrounding the area of outcrop is a broad belt of boulders
and isolated boulders and cobbles. The closeness of the formation
to the surface is inferred by the presence of many silicified and
sparsely fossiliferous boulders and cobbles in the spoil piles or
in the bottoms of the extensive shallow drainage canals in the
area. Many of the boulders and some of the outcrops showed
extensive solutional erosion prior to silification. It is evident that
some of the boulders were originally geodes or parts of small
caverns that were armored through replacement by, or deposi-
tion of, gray to white chert, while the main body of limestone
remained unaltered and soluble. Subsequently the soluble lime-
stone portions of the formation were removed by chemical and/
or mechanical erosion, during exposure at land surface, leaving
the resistant silicified solutional features. Several boulders con-
tained solutional cavities lined with banded, botryoidal, amor-
phous chalcedony, and geode-like, clear, quartz-crystal growths.
The Crystal River, according to Vernon (1951, p. 160) lies
conformably upon the Williston Formation and is unconformably
overlain by the Suwannee Limestone of Oligocene age, or by
younger unconsolidated clays and sands.
In well 805-154-8 the Crystal River is 124 feet thick and
has low to moderate visible porosity and permeability. Small
incipient solutional tubes and cavities were observed in the in-
terval from 182 to 224 feet. Cores were not taken from this forma-
tion in well 801-200-3.
The yield of wells terminating in the Crystal River Formation
is considerably less than those drilled into the Avon Park Lime-






FLORIDA GEOLOGICAL SURVEY


stone, due to the very soft, chalky matrix. The yield of such a
well can usually be increased by deepening the well into one or
more of the underlying formations. The formation will generally
produce a sufficient quantity for domestic supplies.

OLIGOCENE SERIES

SUWANNEE LIMESTONE

The Suwannee Limestone is white, cream, or tan, generally
very soft, granular, detrital limestone which is generally- very
pure. Locally, however, it contains a small amount of fine quartz
sand as disseminated grains. It contains abundant bryozoa, small
mollusca, and large echinoids. Local drillers refer to it as the
"coquina." In some places the upper surface, and/or a zone near
the middle of the formation, is replaced by dark-brown or gray
chert which commonly ranges from a few inches to a few feet
thick. The greatest thickness of chert encountered, or reported,
in the county was 10 feet in well 803-156-11 in Lakeland. The chert
zone occurred from 2081 to 2181 feet, near the middle of the for-
mation. The area of Polk County underlain by the Suwannee Lime-
stone is shown in Figure 5.
In well 805-154-8 the formation is 91 feet thick and contains
thin hard dolomitic zones from 73 to 75 feet. The formation con-
tains some small solutional tubes and cavities which are lined with
small calcite crystals. The lower portion of the formation is
chalky and less granular than the upper part. The Suwannee in
this well has a moderate to low visible porosity and permeability.
The lower few feet appear to be an indistinct pre-lithification
rubble zone, and contain films of black peat along bedding planes.
The thickness of the Suwannee in well 801-200-3 is unknown
due to loss of cuttings and circulation at 136 feet. In this well,
however, the upper 3 feet of the formation was cored, and is a
complete replacement by gray chert. The silicification preserved in
detail many solutional cavities in the limestone. Some of these
cavities contained a filling of cream colored sandy limestone,
which contained a number of Sorites sp., and which is tentatively
identified as limestone of the Hawthorn Formation of Miocene
age. This clearly establishes one reason for the finding of this
particular fossil, as reported by Stewart (1959, p. 22), in what
might otherwise be considered as slightly sandy Suwannee Lime-
stone.






REPORT OF INVESTIGATION No. 44


Thickness of the Suwannee generally ranges from 80 to 120
feet in the central and southern parts of the county. It thickens
rather abruptly from 70 feet in a well southwest of Lakeland
(759-201-1), to 195 feet in a well in south-central Hillsborough
County (746-209-1). In the northern part of Polk County the
formation thins considerably due to both depositional and erosional
thinning, and is absent in much of the northern and eastern
parts of the county (fig. 5).
In several sets of well cuttings the Suwannee Limestone con-
tained some fossils that are diagnostic of the Crystal River For-
mation. Some of these samples also contained a few specimens
of the Suwannee foramanifer Rotalia mexicana, which is not a
durable fossil. Such rocks, though containing predominantly
Crystal River fossils, are interpreted as Suwannee Limestone.
They indicate local erosion and re-deposition of Ocala rocks during
deposition of the Suwannee. An example of such deposits was
found in the upper 36 feet of limestone in well 800-142-1.
The yield of wells terminating in the Suwannee Limestone
is considerably less than those in the Avon Park Limestone, but
is generally greater than the yield of wells in the Crystal River
Formation. The Suwannee furnishes adequate supplies for domes-
tic and small irrigation wells, and it is widely used for these
purposes.

MIOCENE SERIES
The correlation of the formations of Miocene age in Florida
and adjacent states has long been a major geologic problem. Re-
cently great strides have been made with this problem in the
Florida panhandle by Puri (1953b). Major problems still exist,
however, in the peninsular part of the state. Reports by Bergen-
dahl (1956, p. 69-84), Cooke (1945, p. 109ff), Vernon (1951,
p. 178-186), Puri (1953b, p. 15 ff), and others contain summar-
ies of the problem.
In recent years the Miocene and younger deposits in the cen-
tral part of the peninsula have been studied by many geologists
of the U.S. Geological Survey. Some of the findings are reported
by Cathcart and McGreevy (1959), Ketner and McGreevy (1959),
Carr and Alverson (1959), Altschuler, Jaffee, and Cuttitta
(1956), Altschuler, Clarke, and Young (1958), Altschuler and
Young (1960), and others. With these recent contributions some
of the questions regarding the Hawthorn and Tampa Formations
may have been resolved, but in the case of the limestone units






FLORIDA GEOLOGICAL SURVEY


of these formations, which are widely used ground-water aquifers,
a basic practical problem of identification and delineation still
exists.
The chemical and lithologic constitution (Carr and Alverson,
1953, p. 175 ff) of the limestone units of the two formations is
identical for field mapping purposes. The fossil fauna is largely
mollusca which are not individually diagnostic of either forma-
tion, and faunal assemblages are only generally diagnostic of the
early and middle Miocene ages presently assigned to the Tampa
and Hawthorn Formation respectively (Vernon, 1951; Puri,
1953b; Espenshade and Spencer, 1963). Identification of these
formations is made even more unlikely in Polk County because
of dolomitization and because most of the geologic work must be
done from well cuttings, in which large mollusca molds are rarely
recovered intact. Sorites sp., common to the Tampa but not diag-
nostic of it, has not been found in known exposures of the Haw-
thorn, but has been found in well cuttings in both typical
Suwannee and Hawthorn lithology, thus complicating the prob-
lem further. Archaias floridanus, a foraminifer commonly ac-
cepted as diagnostic of the Tampa, has not been found in well
cuttings in this area.
TAMPA FORMATION
Cole (1941, p. 6) identified the Tampa between the depths of
117 and 180 feet in a well 4 miles north of Lakeland (805-157-15)
at the Carpenter's Home, on the assumption that the Tampa
Formation underlies all of Polk County, and on the basis of
general lithology, and an interpretation of fossil evidence. In
his diagrammatic illustration of the well (op. cit., p. 5, fig. 2)
he also includes the interval of 180 to 250 feet in the Tampa.
This well was in use during the entire course of the present in-
vestigation, and exploration of the well was not possible. How-
ever, on the basis of an electric log obtained in well 805-157-16,
approximately 50 feet west of the well described by Cole, the in-
terval 117-250 feet was determined to be the Suwannee Limestone.
Cooke (1945, p. 132) states that the Tampa probably under-
lies all of Polk County south of Lakeland. Vernon (1951) does
not discuss the Tampa Formation in his description of strati-
graphic units. Cathcart and McGreevy (1959, p. 228) found the
Tampa Limestone in western Polk and adjacent parts of other
counties, and report it to be a sandy, clayey, limestone containing
abundant chert fragments and very few phosphate nodules. They






REPORT OF INVESTIGATION No. 44


tate that the limestone is interbedded with clay and sandy clay,
: nd describe a locally developed residual mantle of green calcare-
Sus clay which contains chert and limestone fragments and a
ew phosphate nodules.
Ketner and McGreevy (1959, p. 59-65) consider the Tampa
Limestone to consist of three units, only two of which are present
in Polk County. Their upper, so-called "phosphorite unit" lies
north of this county and does not occur in the area of this investi-
gation. In northern Polk, according to Ketner and McGreevy, the
Tampa is represented by a limestone unit and a clay unit. The
clay unit consists of "greenish-gray to brown clay containing
well-sorted, very fine- to fine-grained quartz sand. Sand ranges
from 5 to 80 percent, averaging about 35 percent." They further
state that the clay unit "apparently grades into the limestone
unit of the Tampa about where the limestone unit of the Haw-
thorn Formation appears." Their limestone unit of the Tampa
is described from an exposure in the Tenoroc Mine of the Coronet
Phosphate Co., northeast of Lakeland, as being fossiliferouss,
yellow, somewhat soft, clayey, and sandy. The sand consists of
very fine- to fine-grained quartz and sand- to pebble-sized, rounded,
polished phosphorite nodules." They do not describe the areal
extent of the limestone unit, but identify it in two drill holes.
Carr and Alverson (1959, p. 14-33) present the most complete
studies and discussions of the Tampa in recent years and extend
the formation eastward from Tampa Bay as far as central Polk
County. According to these authors, the Tampa is a white to
light yellow, soft, moderately sandy and clayey, locally phosphatic,
finely granular, and locally highly fossiliferous limestone. They
state that both marine and fresh water limestones are present,
and that both upper and lower contacts of the formation are
erosional unconformities. Further, they state that limestone com-
monly interfingers with calcareous sandy clay which may be
equivalent to, or be, the Chattahoochee facies of Puri (1953b,
p. 20). If so, this is the first such recognition in this area.
They describe a section of the formation near the Hillsborough
River Dam as illustrating the interfingering of the clay and
limestone beds. They state-"Most clayey beds in the Tampa
limestone are small lenses, but several wells in Polk County, in-
cluding two drilled in 1952 at the Davison Chemical Corp. in
western Polk County, were drilled through about 50 feet of rather
uniform greenish-gray dolomitic sandy clay. This unit is tenta-
tively placed at the base of the Tampa; in the Davison wells it






FLORIDA GEOLOGICAL SURVEY


rests in sharp contact upon pure, white limestone containing
Cassidulus gouldii (Bouve). The wells in which the unit was noted
roughly delimit an area with corners near Mulberry, Lakeland,
Winter Haven, and Fort Meade." The Davison wells referred to
here are wells 754-155-1 and -3 of this report.
The Tampa Formation has been identified in relatively few
wells in this county. Open-file logs of the Florida Geological
Survey by E. W. Bishop and R. O. Vernon identify the Tampa
Formation from faunal evidence in a well south of Frostproof
(742-131-2), and a well at Lake Wales (753-134-4). Examination
of cuttings of the thick Miocene section in a well southwest of
Lakeland (801-200-3), revealed no limestone in the Tampa For-
mation. Cuttings from wells 754-155-1 and -3 were studied and
no evidence was found on which to base identification of Tampa
limestone units in these wells as identified by Carr and Alverson
(1959, p. 25, and fig. 7).
Field evidence obtained during the. earlier phases of this in-
vestigation (Stewart, 1959, p. 22) did not justify an identifica-
tion of limestone in the Tampa in northwestern Polk County. A
slightly sandy limestone, similar in lithology to early descrip-
tions of the Tampa was noted in northwestern Polk, and was
tentatively placed in the Tampa. This has since been identified as
Suwannee Limestone. The same report (Stewart, 1959, p. 23)
also included in the Tampa Formation a "variegated (blue-gray
or blue-green and cream) silty sandy clay" which was thought to
overlie the limestone unit of the Tampa.
Figures 6 and 7 are geologic sections showing the formations
penetrated by wells in the Polk County area. These sections were
constructed from electric and sample logs. Data for the cased
sections in wells were interpreted from drillers' logs. In order to
identify the Tampa Formation in Polk County, it was necessary
to examine logs in southwestern Hillsborough County where the
Tampa Formation is better known and well defined. The corre-
lation of the Tampa Formation in the Polk County area is based
on electric logs from Hillsborough County.
In the Hillsborough County wells, the Tampa consists of a
limestone unit approximately 80-110 feet thick, and an overlying
sequence of interbedded, bluish to greenish gray sandy clays with
stringers of sandy limestone and calcareous sandstone which may
be weathered limestone remnants. The limestone unit overlies,
and is in direct contact with, the Suwannee Limestone. The clay
unit of the Tampa underlies limestones of the Hawthorn Forma-








REPORT OF INVESTIGATION No. 44


A --




to 112 ,-- o
too., .-- FOR &Y R >

I-..~o *(',... j 0 ........

i
i . ... ... .. ... ..--
-33 033 r0tr, ...


-----------------
300 Imt st .-I3
-ON 00
300O- .-aI I I0N3N
700rL --


2 -00- I





on Figure 5.


along lines A-A' and B-B'. Sections located


tion. The clay unit of the Tampa is cased-off in most wells. Some
of these limestone beds have been almost completely replaced by
gray, dense, very hard chert in wells west of Plant City, Hills-
borough County (Menke and others, 1961, figs. 51, 54). The inter-
bedded limestones and clays of the upper unit of the Tampa in
Hillsborough County appear to thin up-dip and merge with the
limestone unit. These units, along with very similar units of the
overlying Hawthorn Formation, appear to have been deposited in
a shallow littoral marine environment suggestive of oscillatory
stages.
The Tampa is readily traced across Hillsborough County and
into Polk County, and it is evident that the individual beds of this









FLORIDA GEOLOGICAL SURVEY


200- 5
SUWANNEE -
LIMESTONE
UNDIFF
SEA RIVER
LEVEL -'
:v INCGLIS
100-

200- AVON


300-

400 -


0 2 3 4 5 miles
=:;r-l


IN G L S

AVON PARK


4 :: 4_ '5 m iles


7. Geologic sections along lines C-C' and D-D'. Sections located c


PARK


c'
CD


'I)
S-1200

ITS -100

SEA
LEVEL

100

-200

300

-400


LIMESTONE


D


tOO-


SUA
LEVEL






300

400-




001-






Figure
Figure 5.


01



I 200

-100

SEA
LEVEL

100

S200

-300

-400

-500

-600

700


~ ~1_1_1


i


1







REPORT OF INVESTIGATION NO. 44


ormation become thinner northward. This thinning is probably
.ue to deposition rather than to removal by erosion. In eastern
fillsborough and western Polk County the Tampa changes up-dip,
'rom a predominantly limestone sequence to a predominantly
clay sequence, and becomes the well-known "blue-clay" of local
drillers, the 50 feet of greenish-gray sandy clay of Carr and
Alverson (1959, p. 25), and the variegated sandy clay of Stewart
(op. cit.). Possibly this clay is also related or identical to the
"residual mantle of green calcareous clay" of Cathcart and
McGreevy (1959, p. 228), and to the "clay unit" of the Tampa
Limestone as described by Ketner and McGreevy (1959, p. 64).
The electric logs available do not indicate any significant
change in character in the rocks above the blue clay of the
Tampa, and it is believed that in Polk County these generally
constitute only the Hawthorn Formation.
To summarize, in Polk County the Tampa Formation is gen-
erally composed of a bluish- to greenish-gray, calcareous, locally
phosphoritic, sandy, shaley clay that contains lenses, fragments,
and occasional thin beds of white to gray sandy limestone. The
blue clay unit of the Tampa was found to be more extensive than
stated by Carr and Alverson (1959, p. 25). This unit underlies
the limestone members of the Hawthorn Formation in all but
local areas along the northern edge of that formation, and east
of the Lake Wales ridge.
The Tampa Formation ranges in thickness from about 10 feet
in well 805-155-2 to about 80 feet in well 752-150-1, although
possibly even greater thicknesses exist.
The blue clay in the Tampa Formation is important in the
hydrology of the area because it is the lower confining bed of
one artesian aquifer and the upper confining bed of another.
The interpretations of the Tampa Formation in the present
investigation tend to agree with those of Carr and Alverson
(1959, p. 21), postulating the existence of Puri's (1953b, p. 19-21)
Chattahoochee facies of the Tampa stage of the Miocene Series
in peninsular Florida.
HAWTHORN FORMATION
In Polk County the Hawthorn Formation consists of massive,
interbedded sandy limestones and sandy clays which are not
individually distinctive. The clays are soft, sandy, phosphatic,
and usually a gray to dark bluish- or greenish-gray. The lime-
stone beds are light-cream to yellow or tan, very hard to soft,






FLORIDA GEOLOGICAL SURVEY


very sandy, clayey, and phosphatic. The beds are really extensive
but not really identifiable or distinguishable. Some of the beds
appear to be nonfossiliferous but where the beds are fossiliferous,
they contain casts and molds of large marine mollusca, silicified
and phosphatized bones, and a few silicified shells. In mine pits
east of Lakeland, the invertebrate fossils occurred in definite
zones or beds that were traceable across the mine.
Generally the basal limestone units have been dolomitized and
are highly crystalline, hard, and resistant. This characteristic
shows on the electric logs as a zone of very high resistivity and
appears to be a more massive bed, as much as 20 feet thick. Along
the northern edge of the formation the limestones are more
highly weathered and earthy, and the dolomitic beds are less
pronounced. Thickness of the formation differs greatly over the
county, ranging from a few feet thick immediately north of the
Lake Parker area to about 160 feet thick in well 747-158-3 at
Bradley Junction. This is perhaps the greatest thickness in the
county.
The upper 2 to 10 feet of Hawthorn limestone were exposed
occasionally in 1954-55 during mining operations in the Saddle
Creek Mine just north of U.S. Highway 92 near Saddle Creek.
A number of sections were measured, described, and photographed
in these mines. Mining has since terminated in this location
and all of the sections described have been mined-out, buried, or
flooded. The upper surface of the limestone in these pits is us-
ually highly eroded and overlain by 1 to 6 feet of brown,
sandy, gritty clay. Locally the limestone is overlain by brown,
well-indurated, clayey, sandstone which, in places, fills the irregu-
larities on the limestone surface. In a few small areas the limestone
is overlain unconformably by lenses of white to dark-green, mas-
sive, dense, blocky clay. Both the clayey sandstone and the dense
clay are included in the Hawthorn Formation.
The limestones are sufficiently permeable to supply water for
domestic and small irrigation requirements, and locally they con-
tain well-developed solutional cavities which enable them to yield
large quantities of water.
The Hawthorn Formation overlies the Tampa Formation un-
conformably, and unconformably underlies sands and clays of
Miocene to Recent age.
UNDIFFERENTIATED CLASTIC DEPOSITS
Overlying the limestones of the county are sands, clays, clayey
sands and sandy phosphatic clays. The age of these materials
ranges from middle Miocene to Recent.






REPORT OF INVESTIGATION NO. 44


PHOSPHATE DEPOSITS
Over much of the area lying west of the northern unit of the
'.inter Haven ridge and the southern part of the Lake Wales
ridge, and generally south of the latitude of Polk City, the
iHawthorn Formation is overlain by sandy clays containing pebble
phosphate, which are in turn overlain by sandy clays and sands
that have been largely leached of their original phosphate con-
tent. In part, these phosphate-bearing beds are a weathered re-
siduum of the Hawthorn Formation, and in part constitute the
Bone Valley Formation generally considered to be of Pliocene
age.
North of the latitude of Polk City and west of the Lake Wales
ridge, outside of the general pebble-phosphate area, the limestones
are overlain by sandy clays which have variously been described
and placed in the Alachua, Tampa, and Hawthorn Formations by
Vernon (1951), Cathcart and McGreevy (1959), and Ketner and
McGreevy (1959), respectively. For the most part these sandy,
slightly phosphatic clays are not readily identifiable in the field
as to formation.
In the area generally east of Polk City, Winter Haven, and
Frostproof, and south of Polk City and Haines City, the lime-
stones are overlain by sandy, slightly phosphatic clays, and marls,
or by clayey sands. In general, these materials are less dense
than the phosphate-bearing clays in the western part of the
county. These clays function as a confining bed for the artesian
aquifers developed in the limestones of the county.
In the remaining part of the county, north and east of Haines
City, the limestones are overlain by generally less clayey and
more permeable marls and sands. In the north end of the Lake
Wales ridge and other parts of this area, the limestones are
overlain by relatively clean or only slightly clayey sands.
COARSE CLASTIC DEPOSITS
Overlying the clays in some areas of the county is a deposit
of clayey, poorly- to well-indurated, quartz sand which is gener-
ally white and very clayey in its lower portion and red to purple
to orange and less clayey in its upper portion. These sands are
micaceous and contain stringers and beds of discoid quartzite
pebbles. Bishop (1956, p. 26) describes these sediments as grading
downward into the Hawthorn Formation in Highlands County
to the south of Polk and as a deltaic unit of that formation. Pirkle
(1957, p. 21) describes them in Alachua County as a marine deposit
of probably Pleistocene age. Ketner and McGreevy (1959, p. 71-






FLORIDA GEOLOGICAL SURVEY


73) discuss this unit, and assign it to the late middle Miocene or
the early late Miocene.
The unit is very thick in the Lake Wales ridge. However, the
unit appears to be absent from well 811-138-3 and others along
this ridge. It is found in many lowland locations, though it is
most prominent in the ridge areas. For example, remnants of the
unit constitute the many low hills and knobs along Fla. Highway
33 in the area north of Polk City.
The unit is used locally as a source for small domestic water
supplies and is a part of the nonartesian aquifer. It is of consid-
erable importance to the hydrology of the county because of the
high storage capacity available and resultant recharge to the
underlying limestones.
The entire county is blanketed by unconsolidated quartz sands,
on which the present soils have developed. These deposits have
been customarily assigned to the Pleistocene, as marine terrace
deposits. Recently, however, Altschuler and Young (1960, p. 202-
203) have established that the surface sands in the Lakeland
Ridge and the phosphate-mining area of west-central Polk County
are "mainly an insoluble residue of lateritic alteration of the Bone
Valley formation, and not a transgressive Pleistocene deposit."
The observed lack of marine terraces, shorelines, or related topo-
graphic features at supposed terrace elevations in this part of the
county strongly supports these findings.
Some terraces do exist in the eastern part of the county.
These are best developed and preserved on the east flank of the
Lake Wales ridge, south and east of the city of Lake Wales.

STRUCTURE
The rocks in Polk County dip at low angles and thicken to the
southeast, south, and southwest, from the north-central part of
the county around the southern end of the Ocala uplift. This
broad dome, or regional anticline, is developed in the Tertiary
formations of northern and central Florida, and it has been
mapped and discussed in considerable detail by Vernon (1951,
p. 47-58, and plate 2).
The Ocala uplift is an elongate dome whose long axis trends
northwest-southeast on an approximate line from Cross City,
Dixie County, to Haines City in northeastern Polk County. Ac-
cording to Vernon (1951, p. 53) the structurally highest point
on the crest of the uplift is in eastern Citrus and Levy counties.






REPORT OF INVESTIGATION No. 44


Vernon's structure map of the Inglis Member (now Formation)
(1951, pl. 2) shows this high point to be outcrops of the Avon
Park Limestone at altitudes of approximately 50 feet above sea
level.
Prior to the work of Vernon (1951, p. 47-52), fracturing and
faulting of the rocks in Florida had not been recognized. He at-
tributes the development of these features to the compressive
forces, and the relief of tensional stresses, associated with the
formation of the Ocala uplift during the late Tertiary. Vernon
states (op. cit., p. 50) "-The poorly consolidated sediments com-
posing Tertiary rocks of Florida favor adjustments to strain by
step fracturing rather than by bending.
Because the tensional and shearing stresses would be greatest
over the uparched area of the Ocala uplift fracturing developed
by them would tend to occur in groups along the axis of the fold
and to indicate the direction of greatest stress and of the
elongation of the arch. If these joints are tensional they would
tend to die out with depth because stretching is greatest toward
the outside and least toward the inside. Available geologic data
indicate that only tensional fractures are present in the area
and that these are shallow."
The present investigation shows that the crest of the Ocala
uplift in north-central Polk County is within a few feet of being
as structurally and physically high as the crest in Citrus and Levy
counties. Figure 8 is a map of the geologic structure in Polk
County, shown as contours on the top of the Inglis Formation.
The contact of the Inglis Formation and the overlying Williston
Formation is conformable and hence represents an un-eroded
horizon which is suitable for structural studies. Structural re-
lationships are also shown by the geologic cross-sections in figures
6 and 7.
The configuration of the Inglis surface is the result of (1) the
highly irregular surface of the underlying Avon Park Limestone,
because the Inglis is relatively thin and did not fill in pre-
existing irregularities, (2) erosion of the overlying rocks down
to the surface of the Inglis, and (3) faulting due to uplift, after
the Inglis was deposited. The northwest-southeast lineation, and
the less prominent northeast-southwest lineation in the county
align with the structural trends established by Vernon (1951,
pl. 2). These features are the result of deep erosion of the Avon
Park Limestone prior to deposition of the Inglis Formation.
The parallelism of the hills and valleys strongly suggests that






FLORIDA GEOLOGICAL SURVEY


Figure 8. Structure-contour map on top of the Inglis Formation.


this erosion was controlled by fractures which parallel the axis
of the Ocala uplift. The work of Vernon (1951, pl. 2) suggests
that many of such fractures may be faults developed parallel
to the crest of the uplift. These faults are the parallel, step-type
faults. The vertical displacement along most faults is 60 feet or
less. Irregularities in the structure contours in figure 8 suggests
that numerous fractures and faults of small vertical displacement
exist in the county, but the available geologic control is inade-
quate to define them.
During this investigation faults were observed in limestone
of the Hawthorn Formation at mine pit exposures in the Lake-
land area. Two of these faults, mentioned by Stewart (1959,
p. 24), are located 0.15 miles north of U.S. Highway 92 and 0.45
miles west of Saddle Creek (fig. 2). The maximum vertical
displacement of beds in one fault zone is 1 foot. Four separate
fractures occur in this zone, which is the site of a solutional






REPORT OF INVESTIGATION No. 44


cavern from which a spring is flowing. A second fault zone is
located about 150 feet to the east and the vertical displacement
along this fault is 6 feet. A spring also flows from a cavern
developed in this fault, but the flow is at water level in the ditch
and is less spectacular than in the first zone described. Normally
water levels in the Hawthorn Formation are about 20 feet above
the top of the limestone in the vicinity of the faults. However,
water levels were temporarily lowered by continuous pumping
from this excavation for mine water supplies, and to keep the
active pits dry.
Another fault was observed in this area, approximately 1,000
feet southwest of the faults described above. The fault (zone?)
strikes N30W, with approximate dip of 80NE. The southwest
side of this fault was downthrown approximately 6 feet. The fault
appeared to be a reverse fault, both from the apparent dip of the
fault plane into the upthrown block and the slight dragging of
beds on opposite sides of the fault.
The existence of the faults observed in mine workings could
not be detected in the subsurface except by a long line of test
holes spaced a few feet apart, and then only if the beds contained
identifiable distinct lithic or faunal zones which could be used
for correlation across the faults. The exposures in mine pits con-
clusively establish the existence of such faults and their relation-
ship to the occurrence of solutional caverns and the occurrence
and movement of ground water.

HISTORY OF STRUCTURAL MOVEMENTS
Vernon (1951, p. 62) states that the movements which formed
the Ocala uplift are post-Oligocene and pre-Miocene in age. He
also indicates that some structural movements may have con-
tinued irregularly throughout later epochs. One of the criteria
that Vernon used for dating the uplift was an apparent lack of
Miocene sediments over the structural high. However, Cathcart
and McGreevy, Ketner and McGreevy, and Carr and Alverson
(all 1959) each report the presence of Miocene sediments over
the crest of the uplift. Carr and Alverson (1959, p. 66) indicate
a late Oligocene time for the inception of the uplift, with renewed
movement along a major fault on its crest in Polk County at the
close of Tampa time.
Several lines of evidence collected in the present investigation
strongly suggest that the Ocala uplift started prior to the depo-
sition of the rocks of the Ocala Group:






FLORIDA GEOLOGICAL SURVEY


(1) Pronounced thickening of the Inglis and Williston Fo,-
mations in present structural lows. This strongly indicates that
the faulting was recurrent through much of Eocene time. Some
of the structural lows are probably downthrown fault blocks.
(2) Pronounced thinning of the Inglis and Williston Forma-
tions over present structural highs, and particularly over the crest
of the uplift in the north-central part of the county.
(3) In a number of places all of the individual beds or units
of the Crystal River Formation and the Suwannee Limestone
thin markedly over structural highs and thicken in lows. This
change in thickness is particularly true in the Hillsborough
County and western Polk County and in northern Polk County.
Such thinning and thickening is depositional rather than ero-
sional.
Thus, it is believed that some areas which are presently struc-
tural highs associated with the Ocala uplift were also structural
highs during deposition of the Ocala Group and later rocks, and
that movements which produced the Ocala uplift as presently
known had their beginnings during the Eocene. The data also
indicate that some movement occurred as late as Miocene time.

SOLUTION FEATURES
The limestones of Polk County contain many inter-connected
openings, ranging from a fraction of an inch to many feet in size,
which are the result of solutional removal of the limestone by
circulating ground waters. Small cavities have been observed in
pieces of limestone that were recovered during well drilling from
depths greater than 1,300 feet below land surface. Many large
cavities, ranging from 1 to 40 feet or more in height, have been
reported by local well drillers. Such openings greatly increase the
water-transmitting ability of the rocks and hence the yield of
wells. Knowledge of these solutional features, therefore, is con-
sidered essential to the understanding of the hydrology and
geology of the limestone aquifers in the county, and in the re-
mainder of the state as well.
Limestone (calcium carbonate) is slightly soluble in pure
water. However, water which contains a small amount of acid will
dissolve limestone much more readily. Rain reaching land surface.
has absorbed carbon dioxide from the atmosphere, and the ga;;
and water combine to form carbonic acid. During infiltration o:!
the surface and percolation downward through the soils the water






REPORT OF INVESTIGATION NO. 44


A ill absorb and combine with additional quantities of carbon
c(oxide from the soil. When the weak acid is in contact with
I mestone for a long period of time, very large amounts of the
I~)ck will be dissolved. Many factors influence the amount and
rate of solution, but two of the most important ones appear to be
tne amount of contact area and the length of time in which
the water and limestone are in contact.
The solution of limestone by circulating water is greatly
facilitated by, and localized in, fractures, joints, and bedding
planes in the rock because water moves more freely through these
relatively large, continuous openings than it does through the
original or primary pore spaces of the rock. Solution and removal
of limestone is, therefore, more effective and rapid along the
fractures, joints, and bedding planes and is most effective at their
intersections. An extreme development of solutional features along
fractures occurs along fault zones in limestones of the Hawthorn
Formation in the Saddle Creek Mine, east of Lakeland. These
faults have only 1 to 6 feet of vertical displacement. One cavern
developed along the fault zones measured 8 feet deep, and another
measured 3 feet deep. These are minimum depths, because ac-
curate measurements could not be made. Both caverns were 2 to
4 feet wide and were confined to the fault zone. The limestone
elsewhere in the exposure is relatively devoid of smaller solutional
tubes, cavities, and honeycomb as noted in the older limestones
in table 4. Though fractures provide the avenue of easiest and
greatest solutional excavation, and hence the largest caverns, the
primary porosity in most of the limestones of this area is suffi-
ciently high to permit some passage of water in response to nat-
ural gravity flow.
In inter-fracture areas, water moves much more slowly; hence,
the quantity passing a given point per unit of time is less, and
solutional excavation is much slower. Small primary pore spaces
slowly enlarge and coalesce and the limestone develops a fine-
textured, honeycomb or spongiform appearance. This type of solu-
tion is speeded by the removal of the shells and tests of marine
invertebrates, particularly those of large mollusca and echinoids,
leaving relatively large open pores. Honeycomb development was
also observed on many random pieces of rock recovered during
drilling operations in other wells.
With the continual movement of ground water and solution,
extensive honeycomb and tubular networks develop simultaneously
with major cavern development along fractures, where the rate








TABLE 4. Solutional features penetrated by wells in Polk County
(e, estimated)

Altitude of ApPrreat
USOS FGL Altitude of bottom of height Probable
well well lad in feet feature in of feature Geologic
number number above rol feet below Inu in feet Type of feature Unit Source of data Reimarks


739-121-4
741-139-2
741-140-1
741,141-1
742-129-1
743-157-1
744-143.1
745-147-1
745-148-3
745-158-1
745-158-8
745-159-2
746-143-1
746-148-1
748-160-1
747-114-1
747-133-2
747-187-1
747-142-2
747-143-1
747-144-2
747-144-3
747-153-2

748-131-1
748-144-2
748-145-1
748-148-1
748-148-4


W-68



W-981



W-4123
W-2304

Wgi-35

W-1726
W-978
W-1110

W-912
Wgi-348
Wi-1008

Wgi-1012
Wgi-342
W-2139
W-1050
W-995


748-148-5 W-639

749-144-1 Wgi-364
749-145-1 Wgi-471
749-145-2 Wi-378


62
149
147
132
104
140
180*
129
138
163
137
160*
223w
149
153
61"
128
147
160
182
216
206
167

243
212e
210
110
110

115

232"
217
231


733
782
+71
273
746
100
+2
+114
+108
-76
689
705
605
116
667
691
677
206
500
812
835
640
643
664
649
113
639
646
1,060
632
612
277
618
630
637
648
669
680
634
760
10


15
7

S
6


6
5
5

2
2
7
18
6
10
5
2
33

2
3
39
?
22
3
8
6
24
7
31
4
2
3
2
4
7
4
4
10
66
20
36


Honeycomb Avon Park
Cavern do
do Hawthorn
do Crystal River
Cavern fill Avon Park
Cavern Hawthorn
do do
do do
do do
do Tampa
do Avon Park
do do
Porous zone do
do Tampa
Cavern Avon Park
do do
do do
Porous zone Hawthorn
do Avon Park
do do
Cavern do
Porous zone Avon Park
Cavern do
do do
do do
Cavern fill Suwannee
Porous zone Avon Park
do do
Cavern fill Lake City?
Cavern Avon Park
do do
Porous zone Crystal River
Cavern Avon Park
do do
Honeycomb do
Cavern do
do do
do do
Porous zone do
Cavern fill Avon Park
Honeycomb Hawthorn


FOS geologic log
Owner
Driller
Owner
Driller's log
Owner
Driller
Owner
do
Driller's log
do
do
Electric log
Driller
Driller's log
do
Driller
Electric log
Driller's log
do
Owner
Driller's log
do
do
do
do
do
do
do
do
do
Electric log
Driller's log
do
do
do
do
do
do
Driller's log
do


Additional asall cavities re-
ported above this







Honeycomb?
"Loae of cuttings"


Honeycomb?
"iUme with crevices"
"Brown lime with crevices"
Size not given, depth to top of
cavern
"Brown lime with crevices"
"Break"
"Big water"
"Green shale and sand"
"Los of cuttings"
"Loss of cuttings-water"
"Brown lime and sand"
"Break"
Occurs in interval 815-822 ft
Honeycomb?




"Brown lime rock crevices"
"Lime shells and sand"






749-149-1
749-16-1
749-159-1
750-142-3
750-145-1
750-148-1


Wgi-10J4
Wgi-344
Wgi-485
W-41


750-151-3 W-1395
750-18-1 -
751-140-1 Wgi-337
761-141-1 W-928
751-145-1 W-974
751-145-2 Wgi-363
751-145-3 Wgi352
751-146-2 W-1006
751-148-1 W-2856
751-155-2 W-2538
752-1844 Wgi-1019
752-141-3 W-4189
752-142-1
752-142-7 W-1111
752-145-3 Wgi-355
752-145-4 Wgi-859
752-146-3 Wgi-460
752-146-4 W-1113
752-150-1
752-201-2 Wgi-1020


752-201-3

753-133-1
753-134-2
753-143-1
753-145-5
753-149-2
753-149-3
753-150-3


Wgi-1021

Wgi-1023
W-500
W-2151
Wgi-167
W-2425
Wgi-371
W-945


126
100e
1550
1760
190e
85



136
151
135
163
176
2120
186*
171
113
183
201
144
171
159
176
167
209
196
125e
120'


1200

183
242
151
162
101
122e
116


530
243
292
605
44
522
524
407
665
2,467
4,455
641
4
689
693
487
606
615
585
507
485
516
233
572
384
551
665
615
53
456
507
524
77
520
591
734
565
620
177
626
617
583
509
448
342
329


50
3
1
5
15
3
2
2
24
62
37
2
5
68
4
8
7
22
11
46
18
1ii
15
11
5
107
112
71
15
90
50

8
68
1
4
35
5
?
43
12
32
20
20
18
5


do
Porous zone
do
Cavern
Honeycomb
Cavern
Gravel
Cavern
Cavern fill
Honeycomb
Porous zone
Cavern
do
Porous zone
Cavern
do
do
Porous zone
do
Honeycomb
Cavern
do
Cavern fill
do
Cavern
Honeycomb
Porous zone
do
Honeycomb
Cavern fill
do
Porous zone
do
do
Cavern
do
Porous zone
Cavern
Cavern fill
Porous zone
Cavern fill
do
Porous zone
Honeycomb
Cavern fill
do


Avon Park
-lawthorn
do
Avon Park
Hawthorn
Avon Park
do
do
do
Oldsmar
Lawson
(Cretaceous)
Avon Park
Hawthorn
Avon Park
do
do
do
do
do
Avon Park
do
do
Williston
Avon Park
Williston
Avon Park
do
do
Suannnee
Avon Park
do
do
Tampa
Avon Park
do
do
do
do
Crystal River
Avon Park
Avon Park
do
do
do
Inglis
Williston


do
Electric log
do
Driller's log
Owner
Driller's log
do
do
do
do
do
do
Owner
Driller's log
do
do
do
do
do
Driller's log
do
do
do
do
Owner
Driller's log
do
do
do
do
do
do
Electric log
Driller's log
do
do
do
do
do
do
Driller's log
do
do
do
do
do


Cavity fill?
"Cave-in"
"Water, sand, heavy flow of
water"
"Porous limestone with sand
lenses" (cavity fill)

"Brown lime with cavities"


"Crevices"
"Crevices"


"Sand"; at top of Inglis?
"Clay with silt"
At top of Inglis?
"Brown lime-crevices"
"Brown lime with crevices"
At top of formation?
"Water sand"
"Shells and water sand"
"Hard brown lime, crevices in
lower section"
At top of Suwannee?
"Hard lime rock with small
openings"

"Vicksburg lime, small open-
ings, no returns"
Well 25 ft east of well above
"Sand coming into well"; at
top of Williston?
"Fu of crevices"
"Sand"
"Water, sand, and gravel"
"No cuttings returned"
"Brown sand and soft lime
rock": at top of formation?
"Lime rock and sand"









TABLE 4. Solutional features penetrated by wells in Polk County (Continued)
(e, estimated)


Altitude of AnPtrent
USG8 FCO Altitude of bottom of height Probable
wellwe ell Ld in feet feature in of feature (Veologic
number number above isal feet below unl in feet Type of feature nitn source. of datl0a RelarkL


763-150-5 W-3304
753-151-2 W-O 5
754-144-1 W'gi-353
7M4-1502 -
754-152-2 W-1801
754-152-3 W-1802
751-1I6-1 W-110
7.l 54-1- W-2098



756-130-1 Wi-1031
750-133- Wgi-103
7856-156-1 Wxi-330
767-133-1 -
757-133-2 WgiO-3i


767-140-1 W-952
757-182-1 W-1441


767-153-2
757-163-3
757-154-3
757-154-5
7W8-139-1
758-1453-1
758-152-3
768-1683-


785-154-1

758-155-2
759-134-1


Wgi-340
W-2241
Wgi-347

Wgi-464
W-1864
Wgi-365
Wgi41

Wgi-338
Wgi341


124
119
122
IiW
147
140
130
200



95,
118
215
185
142

122
117


128
122
1670
234
142
145
1200
123
130
128

258
204


018
510
550
+23
928
009
039
?

502
235
82
506
545
233
332
540
99
275
321
457
31
272
473
552
532
470
480
390
237
465
527
124
225
422
553
491


7
4
33
2
7
8
50
2

10
5
2
G
25
30
85
2
2
7
8
2
2
40
8
0
4
110
40+
2
2
79
7
6
8
11
?


Porous zone
Cavern
Porous zone
Cavern
Ioneycomb
do
Porous zone
Cavern

Cavern and
cavern fill
Cavern fill
Cavern
do
do
Cavern fill
do
Cavern
Porous zone
do
do
do
do
Cavern
do
do
do
do
Cavern fill
Cavern
do
do
Porous zone
Cavern
do
do
Porous zone
Cavern


Avon Park
do
do
Taiiipa
Avon Park
do
do
Sitwanne

Avon Park
Inglis
Crystal River
Avon Park
do
Inglis
Avon Park
Avon Park
Crystal River
Avon Park
do
do
Suwannee
Crystal River
Avon Park
do
do
do
do
do
Inglis
Avon Park
do
Suwannee
Williston
Avon Park
do
do


Driller
Driller's log
do
do
do

do
rdo
do
do
do
do
Driller's log
Electric log
do
do
do
do
Driller
Driller's log
do
do
Tenant
Driller's log
Driller
Driller's log
do
do
do
do
do
do
do


"No cuttings returned"
"Brown lie with open ere-
vice"s"
At top of Lake City?
"Changed by solution action,
likely cavernous"
Exact depth not reported.
cavern occurs in theinterval
from 110 to 158 ft
"Water, sand. gravel, and
small cavern"
"Sand"; at top of Avon Park?


"Coral and wlite sand"; at
top of Avon Park?
"Coral and white sand"




Reported by a local driller
"Cavern, gravel-filled"

Present when drilled
"Lime and water sand"
Full depth not measured
"Sand"
"Brown lime. rock with cre-
vices"
At top of Crystal River?
At top of lagliTs
"Crevices-big water"
Apparent diameter not given


1






759-143-2
759-156-1
759-159-1
759-200-1

759-201-1
759-201-2
800-135-1
800-153-3
800-156-2
800-156-3
800-157-1"

800-159-1
801-138-2
801-189-2
801-139-3
801-146-1
801-200-3


801-201-3
802-134-1
802-136-2
802-136-8
802-148-1
802-143-2
802-143-
802-149-4


802-150-8
802-151-19
802-152-10
802-154-2


WT-1445
W-2153
W-2129
W-2954

W-632
W-6833
Wgi-801
W-724
m- z

W-2015

W-3420
W-4493
Wgi-1042

Core i2





Wgi-1043
W-3305
W-3306
W-3307
W-3633




W-3422


136
155
143
136"

132
135
170
119
139
132
204

146
128
139
149e
150e
1358


134
130
193
'204
147
144
145
130


119
+21
110
1420


511
521
526
552
556
+86
+76
+60
255
530
535
326
341
611
581
138
516
568
+13
52
392
281
20
810
320
412
597
26
412
417
574
65
81
435
+10
672
497
433
820
-0
5
+45
?


?
?
37
7
37
7
3
2
2
10
5
6
2
15
20
20
50
12
11
4
5
10

5
10
7
2
10
55
3
2
6
14
7
4
11
12
8
5


8
?


Cavern and sand
Cavern-no sand
Porous zone
Cavern
Porous zone
Cavern
do
do
do
Porous zone
Cavern
do
do
Cavern fill
Porous zone
do
Cavern fill
Honeycomb?
Cavern?
Cavern fill
Cavern
Cavern fill
Porous zone
Cavern
Cavern
Cavern fill
Cavern
do
Porous zone
Cavern
do
do
do
Cavern fill
Cavern
do
Porous zone
do
do
Cavern and fill
Porous zone
do
do
Cavern


- I-~-~-~ -


do
do
Avon Park
do
do
Hawthorn
do
Tamps
Inglis
Avon Park
do
do
do
do
do
Crystal River
Avon Park
do
Suwannee
Hawthorn
Avon Park
do
Suwannee
Avon Park
do
do
do
Suwannee
Avon Park
do
do
Crystal River
do
Avon Park
Suwannee
Avon Park
do
do
do
Tampa
Suwannee
Hawthorn
7


do
do
Driller's log
do
dj
do
do
di
Electric log
Driller's log
do
do
do
do
Driller
do
Driller's log
do
Observation
Driller's log
Driller
Driller's log
Driller
Observation
Driller's log
do
do
Driller
Local driller
Driller
do
Driller's log
do
do
do
do
do
do
do
Electric log
do
Observation.
Owner


"Three or four 1- and 2-oot
cavities"
Probably not bottom of well
-depth not given in log
"No cuttings returned"

At top of Suwannee?
At top of Avon Park?
"Crevices-hard rock"
"Sand in bottom of this
stream"
"Brown rock with some sand"
"No cuttings returned"
"Lost circulation"
"Sand"
"Water"
0
Dark organic clay, with small i
clusters of satin-spar
"Sand and gravel"
"Lost cuttings"
Top of cavity-depth not re-
ported
At top of formation?
"Sand and mud"

"No cuttings returned"
z

"Blue mud" 0
"Break"; at top of formation? A.
"No cuttings returned" I
"Series of caverns"
"Several openings with wa-
ter"; at top of formation?
"Opening of mud and odor of
gas"; at top of Lake City?
At top of Suwannee?
At top of formation?
Loss of cutting
SDepth to feature and height
D not given, probably in bot-
tom of well







TABiM 4, Solutional features penetrated by wells in Polk County (Continued)
(e, estimated)

Altitude of Apparent
US08 FOS Altitude of bottom of height Probable
well well lad in feet feature in of feature Geologic
number number above mel feet below nul in feet Type of feature Unit Source of data Remarks


802-1564 -
802-167-7
802-167-16 W-4163
802-158-1 W.2767
803134-1 W-458
803-138-1 -
803-137-1 W-1416

803-1451 W-3444
803-145-2 W-2925

803-146-2 W-2720
803-147-4 W-872


803-147-12
803-153-12
803-153-14
803-15-24
808-153-28
803-154-31
803-164-33
803-15614
803-158-1


804-143-1
805-136-1
805-1364
805-186-6


Wgi-1051


W-3425
W-424
W-1800
Wgi-805
W-24


W-4412



Wgi-1053


138'
210
191
193
101I
174
104

145*
155

163
169

141
124'
125
124
127
138
141
148
218


i33e
175e
202
190'


+14
+10
40
471
523
630
459
418
298
326
. ?
+13
.-0
-62
?

476
+61
+27
67
0
12
429
442
402
524

19
25
+17
92


Cavern


do
do


do
do
do
Cavern fill
Cavern
do
Porous sone
Cavern
do
Porous zone
do
Honeycomb

Cavern
do
do
Cavern fill
Cavern
do
Porous zone
Cavern
Porous zone
Cavern fill

Cavern
Cavern fill
do
do


Buwannee
do
Suwannee
Avon Park
do
do
do
do
do
do
7
Hawthorn
do
Suwannee


Avon Park
Hawthorn
do
Suwannee
do
Suwannee
Avon Park
do
Avon Park
do

Hawthorn
Crystal River
do
deo


Driller
do
Owner
Driller's log
do
do
FOB Geol. log
Tenant
Driller's log
do
do
do
do
do
do

do
do
Driller
Observation
Driller
do
Driller's log
do
Driller's log
FOS Geol log

Driller's log
Owner
do
Driller's log


At top of formation?
Depth not given, probably in
bottom of well


"Fine quarts sand and finely
powdered limestone"
Present when drilled
"Sand"
"Lot cuttings" and "Honey-
comb chunks"
Depth and sie not given-
probably in bottom of well
"No cuttings returned-soft
honeycomb"
"No cuttings returned"
"No large cavities-only 4- to
6-inh openings." Depth In-
tervals not reported.

"Open cavern and loss of cut-
tngs"
Sand-filled honeycomb

"Lost cuttings"
Size not given
"Occsionl crevice of cavern"
"Quarts pebbles, peat, porous
limesone, blue clay, and py-
rite"
"Sand, dry, under rock"; at
top of formation?
"Sand pocket"; at top of for-
mation?
"Top of sand pocket-not
drilled into"; at top of Wil-
liston?




805-143-2 W-393
805-147- -
805-149-2 W-4188
805-15-4 W-4018
805-154-8 Core fl



805-155-2 W-3766
805-166-2 W-3769
80-159-1 W-3312
806-187-2 W-3207
806-137-3 W-3799
806-17-4 W-3802


806-187-5 Wgi-109


806-187-9
806-138-1
806-156-2
807-1835-1
807-154-4
807-157-2
807-159-1
807-201-1
808-157-1
808-200-4
809-13853
809-147-1


W-402
W464
W-3771

W-3883
WA.884
Wgi-1059
W-2774


Wgi-1063

W-4275


810-141-1
810-147-1


156
1550
159
182
180W



135
1836
206
178
145
143


133


178
129
136
181
135
154
1750
143
1660
199
155
135


143
151


502
347
426
+48
382
399
644
604
664
+43
+56
54
+34
360
290
338
82
184
372
419
201
317
489
512
484
+41
119
417
426
+86
05
+69
506
+1
5
876

377
72
824
329
334


2
20
2
19




9
2
4
43
10
1+
10
3
5
2
8
4
20
4
6
10
33
7
15
2
75
1
2
10+
14
2
6
18

1+
5
1
1


Cavern
do
Porous zone
do
do
do
Cavern fill
Porous zone
Cavern fill
Cavern
Cavern fill
Porous zone
Cavern
Porous zone
Cavern fill
Cavern
Cavern fill
Cavern
Porous zone
Cavern
Porous zone
Cavern and fill
Cavern
Cavern fill
do
Honeycomb
Cavern
do
Honeycomb
Cavern
do
Cavern and fill
Porous zone
Cavern
Cavern fill
Cavern

Porous zone
Cavern
do
do
d3


Avon Park
do
do
Suwannee
Avon Park
do
do
do
do
Suwannee
Tampa
Suwannee
Hawthorn
Avon Park
Avon Park
do
Crystal River
Avon Park
do
do
do
do
do
do
do
Suwannee
Crystal River
Avon Park
do
Suwannee
do
do
Avon Park
Crystal River
do
Avon Park

do
do
do
do
do


do
Driller
Driller's log "No cuttings returned"
do !Lost circulation"; at top of
formation?
Driller's log "Lost.all circulation"; at top
and observation of' formation.
Driller's log Do
do "Sand pocket"
do "Lost all circulation"
do "Sand coming into hole"
Observation
do At top of formation.
Driller's log "Honeycomb"
do
do "Water and sand"
Driller's log "Soft sand"
do
do "Sand"
do
do "Creviced brown lime"
do
do "Cuttings pass off into sub-
surface streams"
do "Cavity with coarse brown
sand
do
FGS GeoL log "Sand"
do "Sand with some limestone
fragments"
Observation "6- to inch cavities-e8 to
95 feet"
Driller
Driller's log
Driller
do
Driller's log Depth to cavity not given-
probably at bottom of well
Driller 10-ft cavern, then into clean
sand
Driller's log "No cuttings returned"
Driller At top of formation?
do "Sand"
Observation (Dolomite pebbles up to 1-
inch diameter recovered
from floor of cavern)
do "Honeycomb"
Driller's log At top of formation?
do
do
do


01
to







TABL 4. Solutional features penetrated by wells in Polk County (Continued)
(e, estimated)

Altitude of Apparent
1808 FGO Altitude of bottom of Probable
well well Ild in fees feature in of feature Geologie
number number above mel feet below mel in feet Type cf feature Unit Source of data Remarks

810-147-1 161 344 1 do do do


810-155-1 W-3866
811-188-3 W-4199
811-149-1 25
813-139-1 Wgl-1068

813-139-2 -
813-149-1 W-S(04
813-201-1 W-5352


814-138-1 -
814-139-1
815-139-1 Wgi-1009
815-157-1 W-3810
815-157-2 W-3839


816-146-1



817-139-2
817-150-1
818-140-1
818-151-2


W-4680 128



209
Wgi-1073 159
Wgi-1074 218
114


349
372
+19
614
305
315
447
347
4689
649
298
20
49
95
105
130
140
116
361
394
+65
11
1434
21
31
36
41
40
17
261
264
276
94
287
216
602
602
+34


1
3
2
2
60
5

7

2
5
10
1
91
123
5



1
3

51
13


1



13


10
5
1+
2+


do
do
Porous zone
do
Cavern
Cavern fill
Porous zone
Cavern fill
do
do
do
do
do
Porous zone
Honeycomb
Cavern
do
do
Cavern fill
Porous zone
Cavern
Porous zone
Cavern
Porous zone
Cavern
Hon ecomb
Cavern
Cavern fill
Cavern
do
Honeycomb
Cavern fill
Cavern
Cavern fill
Cavern
do
Cavern fill
Cavern


do
do
Suwannee
Crystal River
Avon Park
do
do
do
do
do
do
do
do
Williston
Inglis
Avon Park
do
do
do
do
Crystal River
Williston
do
Inglis
do
do
do
do
do
do
Avon Park
do
do
Avon Park
do
do
do
do
Crystal River


do
do
Electric log
do
Owner
do
Driller's log
Driller
do
do
do
Observation
do
Observation
do
do
do
Driller
Driller's log
do
Observation
do
do
do
do
do
do
do
do
Driller
Observation
do
do
Driller's log
do
do
Driller
do
Owner


"Sand"
"No cutting returned"
"Sand bed'
Do
Do; at top of Lake City?
Do
Quarts and cavity fill
No Cutting returned
Few cuttings returned


Limestone and sand beds
"No cuttings returned"
"No cuttings recovered"
Do
Small cavities
With quartz sand
Sand eavity-s prevented fur-
ther drilling
Size not reported; at top of
formation?
No cuttings recovered
Quartz sand-prevents drill-
ing
"Sand"


"'Sand"
At top of Williston?





818-155-2 Wgi-1006


13 Filled caverns
B Cavern
1 Cavern fill


Ingiis
do
do


Dnller
do
do


"iUlwoman A .-.. .:.";
- top of formation?
"Sand and muck"


108*





FLORIDA GEOLOGICAL SURVEY


of development is much faster. Tributary flow thus becomes es-
tablished in an elementary pattern, controlled by fractures, and
the cavern system is enlarged and extended with time, much as
surface drainage systems are developed. This process progressively
increases the water-transmitting ability of the limestones.
As the solutional caverns become larger the roofs, in some
instances, may slowly become incapable of supporting the over-
lying materials and eventually collapse. If the collapse extends
upward to land surface, a sinkhole is formed.
Obviously cavern systems functioning as ground-water con-
duits or drainage systems must have a terminus, or point of
discharge. In artesian aquifers, such as those in this- area
(Stewart, 1959), the cavern systems will not discharge at land
surface unless land surface is below the piezometric (pressure-
head) surface of the aquifer concerned. In such discharge areas,
concentrated flow at land surface, as artesian springs, will occur
where the confining beds are breached. It is likely that most
of the discharge of cavern systems of Polk County occurs through
the multitude of artesian springs in Hillsborough and other ad-
jacent counties to the south and southwest. The only significant
artesian spring in Polk County is Kisqengen Spring, southeast
of Bartow. The so-called "Ft. Meade Spring," just east of the
town of Ft. Meade, is actually a man-made pool fed by a flowing
artesian well.
Diffuse discharge at a low rate probably occurs as general
upward leakage through confining beds in areas where the arte-
sian head is great, and confining beds are not visibly breached.
In Polk County such an area probably exists over much of the
valley floor of the Kissimmee River below Lake Kissimmee, and of
the Saddle Creek-Peace River system below U.S. Highway 92,
east of Lakeland.
CAVITIES
During this investigation data was compiled on open cavities,
honeycomb zones, and zones in which drill cuttings were lost at
depth in the limestones of the county. Beds of unconsolidated
quartz sand and similar sands encountered in the bottoms of
open caverns are all interpreted as cavity fillings, because such
deposits are not known as regular primary sedimentary deposits
in the rocks of Tertiary age in central Florida. Such deposits,
along with the other solutional features, are tabulated and pre-
sented in table 4. The locations of these wells and the altitude of
the base of the deepest feature encountered are shown in figure 9.






REPORT OF INVESTIGATION NO. 44


i. 9. Ma, .w. t- h location o~ \ells pen-.tatn sou.o, fet re
The r.da .of o n featue n te h ,

cry: a .-,, Avon P ; .Li.... i .... te se totl
t I ,--Z7 ^ FR ..STPR o0,




the /s n epne an of solutional fear h h
/ POLK COUNTY


Figure 9 Map showing the location of wells penetrating solution features
in the limestones

The preponderance of solutional features in the harder, more
crystalline, Avon Park Limestone is evident, and these total 65
percent of all solutional features recorded. Many of the wells
shownn table 4 do not penetrate the Williston and Inglis Forma-
tions and the Avon Park. Thus the number of solutional fea-
tures in the Avon Park may actually exceed the proportion indi-
cated. The table includes data from 190 wells and it records 274
separate features. It is believed that if detailed drilling logs were
available from all Wells in the county, the actual number of wells
which penetrate solutional features would be vastly more than
the wells now tabulated. However, such logs are available for less
than 400 of the more than 1,300 wells inventoried during this
investigation (Stewart, 1963, table 1).
A number of general observations may be made from figure 9:
1. Multiple zones of cavern development, at different altitudes,
exist in the same local area, as in the area west of Lake Hancbck.






FLORIDA GEOLOGICAL SURVEY


2. Locally the data show a definite correlation of altitude of
cavern zones, as in the area immediately west of Lake Buffum
at -650 msl, and in the area southwest of Lake Parker at -550
msl. These zones may be part of an integrated cavern system.
3. Four wells (750-148-1, 754-152-2, 747-137-1, and 741-139-2)
penetrated cavern systems or solutional features at depths in
excess of -900 msl; one of these (750-148-1) penetrated a honey-
comb zone at -4,455 msl.
4. Numerous solutional features exist at altitudes above msl,
particularly in northeastern Polk County.
5. Caverns have developed in areas where the limestone is
deeply buried, as in the southwestern part of the county.
6. In general, the caverns of the Lake Wales ridge are at
shallower depths below sea level than those of other parts of the
county in the same latitude.
A comparison of figures 4, 5, and 9 suggests that the general
distribution of wells known to penetrate solutional features is
more closely related to the distribution of well data, than to the
geology of the area. Data are very sparse for southeastern Polk,
because few wells have been drilled in this area. As this is an
area of general artesian flow and upward leakage, it may be
assumed that large caverns such as those known and reported in
Hillsborough County may exist in greater numbers than the map
indicates.
In general, there appears to be an increase in depth below
both land surface and msl of the deepest local cavern zones with
increasing distance from the north-central part of the county,
following the slope of the piezometric surface and formational
dip.
The study of the cores from wells 805-154-8 and 801-200-3
produced detailed data on the solution features of the underlying
limestones. The cores show a concentration of solutional fea-
tures in the Avon Park Limestone. A series of cavern develop-
ments and subsequent collapse and filling in the Avon Park Lime-
stone, and a few features in the underlying Lake City Limestone,
occurred prior to dolomitization of these formations. These caverns
show, in many cases, a second stage of solutional excavation
and fill which occurred after dolomitization. In several instances
these solutional features strongly suggest a third stage of solu-
tional excavation, now occurring in the second stage fill. Ab-
stracted logs of these two test holes and of well 815-157-2 pre-
sented earlier indicate the extent of solutional features observed.






REPORT OF INVESTIGATION No. 44


In addition to this series of features, three separate caverns
were penetrated in the Avon Park Limestone in well 801-200-3;
these were in the intervals of 440-445 feet, 5401/-5471/2, and
7291/-7311/ feet, respectively. The upper cavern (440-445 feet)
was underlain by quartz sand and mud fill from 445-455 feet.
The middle cavern was apparently underlain by 1051/2 feet of soft
mud and sand fill, and/or very soft honeycomb limestone, because
casing was set through this interval without drilling.
Limestone-filled solutional cavities were also found in the
upper surface of the Suwannee Limestone in well 801-200-3. After
development of the solutional features, the surface of the Suwan-
nee was replaced by chert. Limestone of Miocene age [Tampa (?)
Formation] which contained numerous Sorites sp. was then de-
posited and filled the preserved solutional features.
No significant solutional features, other than some fine honey-
comb, were observed in the soft, chalky, highly calcareous Suwan-
nee Limestone or Crystal River Formation in wells 801-200-3 and
805-154-8.
SINKHOLES
Undoubtedly the most spectacular surficial evidence of solu-
tional activity is the formation of collapse sinkholes. Thirty
active sinks were recorded in west-central Florida from 1953 to
1960. Nineteen of these have occurred in Polk County, including
those referred to by Stewart (1959, p. 13-16), and all of these
are listed in table 5. Location of these sinkholes are shown in
figure 10.
Because of the relatively small diameter and observable depth,
all of these sinks are believed to have had their origin in the
upper-most limestone of the area concerned. Study of the data in
table 5 and the piezometric, structural, and geologic maps pre-
sented elsewhere in this report indicate a wide variety of local
conditions at the different sites. None of the sinks occurred on
local topographic highs. Land surface at the sites did not exceed
150 feet above sea level. Land surface at 13 sites is 70 feet or
less above limestone; at 5 sites the depth to limestone ranged
from 100 to 225 feet. Only six sites were not closely associated
with, or adjacent to, pre-existing sinkhole areas. Figure 11 shows
two of the sinkholes developed recently in the county.
Between 1953 and 1960, 11 sinks were formed in adjacent
Hillsborough, Pasco, and Hernando counties, and probably others
occurred elsewhere. Though most of these sinks have been of






FLORIDA GEOLOGICAL SURVEY,


Figure 10. Map showing location of recent sinkhole collapses.


small dimensions, their sudden appearance has caused consider-
able local alarm. The formation of sinkholes is a completely natural
occurrence and perhaps most vividly illustrates the principal
geomorphic process operating in this area. Other such collapses
in the future are a certainty.
The multitude of round, closed-in basin lakes in central Flor-
ida and Polk County are widely held to be of sinkhole origin,
and as such are evidence of considerable solutional activity in-the
geologic past. Though many of them may have occurred prior to
the historic past, they are none the less spectacular due to their
size and numbers. The smaller lakes in Lakeland, such as Lakes
Mirror, Wire, and Morton, are almost certainly single sinks. Be-
cause of their very circular shoreline, larger lakes, such as
Hollingsworth in Lakeland, Ariana in Auburndale, and Howard
in the City of Winter Haven, and scores of others in the county,
are also believed to be single sinks. A number of large lakes, with














TABLE 5. Records of the occurrence of recent sinkholes in Polk County
(Reported data shown by "r")

Location Diameter Depth in Altitude in
Number Date of Mode of in feet at feet below feet above Quarter Township Range Nearest
(on fig. 18) collapse occurrence land surface land surface land surface section Section south east town

1 1958-84 (4) Instant 8-12 12-40 r 115-t SE 6 30 25 In Bartow
NE 7
2 4- -4 do 8 r 8 r 130 NW 15 28 24 Lakeland
3 9- -54 do 22 4+ 110- NW 11 28 24 Lakeland
4 5-8-55 do 80 80 138 SW 14 29 24 Highland City
(40 r)
5 4-7-56 do 83 20+ 120 NE 7 30 27 West Lake Wales
(40 r)
6 4- -56 do 40 r 4r 175 : NW 34 30 26 Alturas
7 4-9-56 (2) 3 months 30 1-14 126 NW 28 29 25 Bartow
2 hours 100 i
8 4-10-56 Instant 75 r 10 r 130l SE 34 28 26 Winter Haven
9 7- -57 do 50 16+ 150 NW 22 29 24 Lakeland
10 9-10-57 do 8r 10 r 115 NE 7 30 25 In Bartow
11 11-8-58 do 60 r 40 r 1001: SW 0 30 25 Bartow
12 4-17-59 do 5 9-10 140 SW 30 27 24 Lakeland
13 5-5-69 do 70 r 40 r 130 NE 33 28 26 Winter Haven
14 5-28-60 do 30 unknown 140 SW 17 27 23 Kathleen







FLORIDA GEOLOGICAL SURVEY


Figure 11. Photographs of recent sinkhole collapses.






REPORT OF INVESTIGATION NO. 44


irregular or complex arcuate shorelines, such as Bonny, in Lake-
land; Gibson, near Lakeland; Crooked Lake, at Babson Park;
and many others, are a coalescent group of smaller sinks, or are
more properly referred to as valley sinks. For example, Lake
Bonny in Lakeland, at a stage about 6 feet below normal in June
1956 was shown to be formed by a group of smaller adjacent or
coalescent sinks by aquatic grass and other vegetation growing
around the periphery of the small sinks in the shallow water.
Many sinkhole basins contain only ephemeral lakes or ponds.
Such basins range from several hundred feet in diameter and
scores of feet deep to a few feet in diameter and depth. The
larger, deeper sinks are profuse in the Lake Wales ridge section
where the relatively porous overburden is very thick.
The original depth of the sinks (or depth to point of collapse
or cavern) is generally unknown. Wells on, or near, the floors of
sinkhole basins are few because well drillers have found that
unconsolidated materials in such basins may extend to great
depths. This requires great amounts of well casing, and fre-
quently presents considerable difficulty in drilling, installing the
casing, and developing the well. To further complicate drilling
in such locations, the honeycombed, fractured, or cavernous lime-
stone, is commonly impregnated by sands, silts and muds which
reduce the yield of the wells, and require additional casing in
most instances.

HYDROLOGY
Hydrology is the science that relates to water on and within
the earth and in the earth's atmosphere. Water moves continually
from one to another of these environments, and man diverts a part
of it, temporarily, for his use before releasing it back into the
cycle.
A relatively small part of the rainfall runs off over the land
surface because of the permeable sand cover. A larger part of the
rainfall is returned to the atmosphere by evaporation from the
soil, bodies of surface water, and the vegetation. Part of the rain-
fall infiltrates the surface and percolates downward into the soil,
and much of it is held as a film on soil particles, taken up by
plants, and subsequently transpired back into the atmosphere.
The water in excess of these requirements percolates downward
through the soil and remainder of the zone of aeration, and
eventually reaches the zone of saturation to become ground water.






FLORIDA GEOLOGICAL SURVEY


Within the zone of saturation, water moves through the earth
materials, in response to gravity, to points of discharge such as
springs, lakes, streams, oceans, and wells.
The appraisal of the ground-water resources of the county is
at best only an approximation, because none of the quantities
involved in the various factors can be measured directly runoff
and precipitation. Techniques for accurate measurement of evapo-
ration and transpiration do not exist as yet, and even adequately
detailed measurement of rainfall and runoff are seldom possible
and always costly.
Because of variations in climate, and the requirements of man,
it follows that the quantity of water available in an area will
differ from year to year.

SURFACE WATER
STREAMS
In general, surface drainage in the county is poorly developed
and is almost entirely of two types: (1) basins of interior drainage
(without surface outlet), and (2) streams of very low gradient
which, for the most part, do not occupy well-defined valleys. In
many places these streams have not cut well-defined channels.
The county lies within six major drainage basins, as ordinarily
defined, and these are shown in figure 2.
Approximately 15 percent of the county is drained by the
Withlacoochee River which forms part of the northern boundary
of the county (Heath, 1961, p. 8 and fig. 8). The river flows west
into Pasco County, where it turns sharply north and empties into
the Gulf of Mexico near Inglis in Levy County.
About 4 percent of the west-central part of the county west
of the Lakeland ridge is in the headwaters of the Hillsborough
River and about 8 percent of the southwestern part of the county
(Heath, op. cit.) is in the headwaters of the Alafia River.
The area between the Lakeland and Lake Wales ridges, and
south of Providence, Auburndale, Lake Alfred, and Haines City,
is in the basin of the Peace River. Approximately 35 percent of
Polk County lies in this river basin (Heath, op. cit.).
A narrow finger of the headwaters area of the Oklawaha-
St. Johns River basin extends into northeastern Polk County,
along the west flank of the Lake Wales ridge, north of .Haines
City. This area (2-3 miles wide) represents 3 percent of Polk
County (Heath, 1961, p. 10), and is drained by Green Swamp Run.






REPORT OF INVESTIGATION NO. 44


The eastern 35 percent of the county (Heath, op. cit.) is in
the basin of the Kissimmee River.
Tributaries of all of these rivers are generally short, poorly
defined, and few in number. The course of the Withlacoochee in
this county is a thickly timbered cypress river-swamp that ranges
from about a hundred feet to more than a mile in width. Where
the channel of the river can be defined within the swamp, it is
generally less than a hundred feet wide. The Peace River has a
well-defined channel between Bartow and Ft. Meade.
Table 6 shows the annual runoff in three drainage basins
TABLE 6. Annual runoff by drainage basins, in inches of water over the basin
(Data supplied by Surface Water Branch, U.S. Geological Survey,
Ocala, Florida)

Station 1954 1955 1956 1957 1958 1959
Alafia River at Lithia,
Hillsborough County 14.28 8.40 5.37 18.56 13.26 34.42
Area: 335 sq. mi.
Peace River at Bartow,
Polk County 8.00 3.89 4.47 14.40 10.49 28.16
Area: 390 sq. mi.
Peace River at Zolfo Springs,
Hardee County 12.21 5.63 5.42 14.63 12.10 27.52
Area: 840 sq. mi.
Kissimmee River below Lake
Kissimmee, Polk County 10.93 4.28 2.60 9.30 9.27 20.38
Area: 1,609 sq. mi.


during this investigation. Runoff is given in inches of water over
the basin area. The stations listed here are those nearest to, or
within, the county in the drainage basins. Runoff from the
Withlacoochee and Hillsborough basins cannot be evaluated be-
cause of diversions through the Withlacoochee-Hillsborough over-
flow. The Withlacoochee and Hillsborough basins therefore are
not included in Table 6 or in the sections on recharge. Numerous
other stations exist on tributary streams and canals within the
county. The records of these basins, only a few years of which
are given here, show great differences in runoff from each drain-
age basin from year to year, and between basins during the same
year.
The ridges are drainage divides, however, actual surface runoff
from them is almost nil due to the thickness and permeability of
the surficial sands, and to the numerous closed basins of interior
drainage located on the ridges. For this reason large areas within
a drainage basin actually contribute very little direct surface run-






FLORIDA GEOLOGICAL SURVEY


off to streams. Rainfall in these areas infiltrates to the water table
and percolates through the nonartesian aquifer in response to
downward loss, lateral flow, and storage. A part of this water is
eventually discharged into surface-water bodies, but only a few
such bodies are a part of stream courses.
LAKES
Heath (1961, p. 8) states "Nearly 500 lakes, ranging in size
from less than an acre to more than 35,000 acres (55 square
miles), lie within the county and along its borders." Nine of the
largest lakes are within the broad eastern lowland. They are con-
nected to the drainage systems by means of natural or artificial
channels. It is unlikely that these lakes lose water downward
through the bottoms because they are within areas of significant
artesian flow. Most of the other large lakes in the county are
likewise connected to drainage systems. A majority of the lakes
in the county, however, are closed basins of interior drainage at
the present time.
The entire length of the Lake Wales ridge in this county is
pocked with and flanked by innumerable closed basin lakes. There
are also many sinkhole basins without lakes, and like most of the
lake basins they have no surface outlet. The porosity and perme-
ability of the thick surficial sands of the ridge do not permit
surface runoff, and the thickness and permeability of the mate-
rials filling the bottom of these sinks likewise do not permit pond-
ing of water. The bottoms of these dry sinks are 20 to 50 feet
or more above the water levels in the underlying artesian aquifers,
while water levels of the lake-filled basins are generally 2 to 10
feet above these ground-water levels. It seems likely that in much
of this area, ground water percolating down the slopes of these
dry basins is going into- the artesian limestone aquifers as re-
charge.
These dry sinks range from 100 to 1,000 feet in diameter at
the top of their funnel-shaped basins, but most are 200 to 500
feet in diameter. Topographic depth of the sinks ranges from
25 to 75 feet, the smaller and more shallow basins being found
on lower parts of the ridge flanks or within larger and deeper
basins.
In the Winter Haven and Lakeland ridges, and in the central
and northern inter-ridge areas, dry sinks and basins are few in
number, though lake basins of interior drainage are numerous.
In these areas the surficial sands are not as thick as in the Lake






REPORT OF INVESTIGATION No. 44


Wales ridge. In these two areas the surficial sands are underlain
by greater thicknesses of less permeable materials, and, being
lower topographically, the water table is closer to land surface.
The water levels of the artesian systems are also closer to land
surface except in the highest parts of these ridges. These factors
all operate to increase the percentage of lake-filled basins in these
areas.
The lakes of the county are of significant value to the hy-
drology and economy. They serve to moderate temperatures and
climate, they function as reservoirs for water which might other-
wise leave the area more rapidly as streamflow, and they provide
large supplies of water for irrigation and recreational purposes.
Lakes supply numerous lawn irrigation systems in the cities
and towns along the Lake Wales and Winter Haven ridges. In
Lakeland and the Lakeland ridge section generally, the use of
lakes for lawn and citrus irrigation is relatively much less than
in the other areas.
The City of Lakeland pumps water from Lake Parker and
Lake Mirror for cooling purposes in adjacent power plants. Lakes
Gibson, Crystal, and Bonny have been used for citrus irrigation
in the past, but such usage has been discontinued in recent years
largely because of legal proceedings and injunctions. Scott Lake,
south of Lakeland, is still used extensively for citrus irrigation
whenever irrigation is necessary in the surrounding groves.
Lakes and ponds fluctuate in response to rainfall, ground-
water inflow, evaporation, downward loss to underlying aquifers
by percolation through the lake bottom, to surface inflow and
outflow, and to pumping. The quantities of water involved in these
transfers are dependent on topographic, climatic, and geologic
factors, and the hydrologic setting of the individual lake basin.
The net effect of these factors differs widely from one basin to
another, as shown by the hydrographs in figure 12. Relative im-
portance of the controlling factors is not always evident. As a
result, the prediction of the effect of individual factors on a
given lake is not valid without evaluation of the other factors
involved. Detailed discussion of the basins of Lake Parker and
Scott Lake in the Lakeland area, and the response of these two
lakes to the factors above, are presented in the section of this
report entitled Special Problems.
Lakes Wire and Hollingsworth are in the City of Lakeland and
on the Lakeland ridge. Lakes Deeson, Crystal, and Bonny are on
the lower ground along the east flank of the ridge. Hydrographs

















LAKEiWIRE


. . .


LAKE HOLLINGSWORTH

. . .. . .


13=2
31


'138




.136


- I







:139
1294





'33

13
m



























.131


126

125

iZ4
14


12




6 ;


AAINFALL AT LAKELANO 4






r F









F AMJJA SONOIJMAMJJASONDJFMAMJJASONODIJFUAJJASON5JFMAUJJ ASONCJFMAIJJJASON
;954 1995 1 1957 958 959


Figure 12. Hydrographs of water levels in Lakes Wire, Hollingsworth,

Deeson, Crystal, and Bonny near Lakeland and rainfall at Lakeland, 1954-59.



74






REPORT OF INVESTIGATION NO. 44


for nearby Lakes Parker and Scott are presented in later sections
of this report. Additional data on lake levels, collected as a part
of this investigation, may be found in the basic data report
(Stewart, 1963). Lakes Hunter, Beulah, Morton, Mirror and
Gibson, all in the ridge section near Lakeland, fluctuate closely in
time and amount with Lakes Wire and Hollingsworth.
Water levels in Lakes Deeson, Crystal, and Bonny, near Lake
Parker, declined about 6 feet, and Lake Wire declined 1 foot
between December 1954 and July 1956, whereas the water levels
in Lakes Parker and Hollingsworth and other nearby lakes re-
mained about the same. Hydrographs of the six lakes for 1954
correlate reasonably well.
Lakes Bonny, Crystal, and Deeson have no surface inflow or
outflow. Topographic gradients within the basins are generally
low, and the slope of. the water table is assumed to be low also.
The average flow of ground water into the lakes is probably
equivalent to only a few inches per year over the lake surface, and
this amount was undoubtedly below average during the dry period
from January 1, 1955 through June 30, 1956. Ground-water out-
flow in the nonartesian aquifer is believed to be zero.
One phosphate test hole near the west shore of Crystal Lake
showed predominantly sandy materials extending from the sur-
face down to the limestone bedrock. A good hydraulic connection
such as this may also exist in parts of Lakes Deeson, Crystal,
and Bonny, permitting relatively rapid downward leakage.
During the same dry period (January 1955 to June 1956),
pumping from the artesian aquifers increased as recharge de-
creased, lowering artesian water levels 5 to 10 feet. This in-
creased the hydraulic gradient between the lake levels and the
artesian aquifers and probably increased the rate of leakage from
the lakes.
The combination of decreases in rainfall and ground-water
inflow plus increase in evaporation and vertical leakage appear
to have been sufficient to account. for the decline in lake levels.
With the return of near- or above-normal rainfall late in
1956, lake levels began to rise. In November and December 1956,
the outlet of Lake Parker was raised 1 foot by the City Engineer
of Lakeland. The surplus water created was then pumped into
Lake Bonny. The pumped water, plus the rainfall, accounts for
the sharp rise in the level of Lake Bonny in November 1956,
which amounted to approximately 2 feet. Continued above-normal
rainfall in most of 1957 returned the lakes to, or above, their






FLORIDA GEOLOGICAL SURVEY


1954 levels. Lake Deeson was the only exception to this in the
Lakeland area.
The cause of this lack of recovery by Lake Deeson is uncertain
and data are few. A major factor may be very localized below-
normal rainfall. Similar instances are indicated on the hydro-
graphs of Lake Bonny in September-October 1955, and at other
times. This is possible because of the predominantly thunder-
storm-type of rainfall in the entire area. Lake Deeson's failure
to recover in 1957 and in 1959, as well, may also be due in part
to increased local pumpage and downward leakage from the basin.
The lakes all declined in 1958 because of below-normal rainfall.
In 1959, record high rainfall was established at the Weather
Bureau office at Lakeland when a total of 70.24 inches was re-
corded. All the lakes, except Parker and Deeson, exceeded their
1954 levels by significant amounts. In September 1959, it was
necessary for the city and county to reverse the procedure of
1956, and excess water from Lake Bonny which threatened shore-
line property was drained into Lake Parker.
Stage measurements of Lake Ariana in Auburndale, and Lake
Hancock near Highland City, in 1958 and 1959 (Stewart, 1963,
p. 106) show that these lakes also fluctuate closely with those in
the Lakeland area. The range of fluctuations of these lakes ap-,
pears to be about equal to those of Lake Wire for the 2-year
period.

EVAPOTRANSPIRATION
The term evapotranspirationn" has been used to denote the
return of water from the earth to the atmosphere by direct
evaporation and by the life processes of plants. It includes evapo-
ration from water surfaces as well as soils and vegetation, and
the transpiration by vegetation.
The source of data on evaporation from free-water surfaces
nearest the area described in this report is a standard U.S.
Weather Bureau evaporation pan at the Orlando Water Plant in
Orange County. Evaporation and other climatic factors at Or-
lando differ somewhat from those at Lakeland, but in the absence
of local data, the data from the Orlando station are used in this
report. A pan coefficient of 0.7 is applied to correct the annual
rate of evaporation from the pan to that from a lake (Follans-
bee, 1934, p. 705). The average, corrected, annual evaporation
at the Orlando Water Plant, for the period January 1954 through






REPORT OF INVESTIGATION NO. 44


December 1958, is 40.6 inches. This compares favorably with the
(ata obtained from the now-abandoned Lake Hiawassee station
of the U.S. Weather Bureau, near Orlando, from 1940-1946. This
average also seems appropriate in view of available rainfall and
runoff data.
Meyer (1942), on the basis of computed evaporation, produced
a series of evaporation maps which showed the Polk County area
to have an annual average evaporation of 50 inches (op. cit.,
map no. 4). Meyer's map No. 10 shows this area to have equal
mean annual evaporation and precipitation. Since considerable
runoff does occur in this area (table 5), the evaporation rate
proposed by Meyer is inappropriate.
Transpiration is the release of water from plants during their
life processes. No accurate method has been developed for meas-
uring the rate of transpiration of various types of vegetation in
a humid subtropical climate such as that of Polk County, but
transpiration is undoubtedly a significant factor in the water
budget of this area. Studies by Koo (1953) indicate that transpir-
ation of citrus trees is very high. His study utilized test plots
of 15-year old Marsh grapefruit trees, and results indicate that
average daily consumption of water from the nonartesian aquifer
is about 34.2 gpd/tree (gallons per day). The daily consumption
varied greatly during the year. Based on this average, and 65
to 70 trees per acre, annual transpiration losses would be about
30 inches per year. If allowances are made for direct re-
evaporation from the foliage and land surface, and transpiration
by cover crops and weeds, it is seen that evapotranspiration rates
in citrus groves approach open-water evaporation rates in the
area. This is also indicated by the work of Penman (1956), who
states that transpiration in humid climates near the equator ap-
proaches a factor of 0.7 of open-water evaporation. The general
close relationship of evaporation and transpiration is also stated
by Blaney (1956). For purposes of this report the evapotranspira-
tion rate of 40 inches per year is believed to be reasonable.

GROUND WATER
OCCURRENCE
Ground water is the subsurface water in that part of the zone
of saturation in which all pore spaces are filled with water under
hydrostatic pressure. It is derived from that fraction of rainfall
which has percolated downward, through the soil and zone of






FLORIDA GEOLOGICAL SURVEY


aeration, and reached the zone of saturation. The ground water
then moves laterally, under the influence of gravity, toward places
of discharge such as wells, springs, streams, lakes, or the ocear.
Where hydrologic conditions permit, some of the water may move
downward into other underlying aquifers.
An aquifer is a formation, group of formations, or part of a
formation, in the zone of saturation, that is permeable enough to
transmit usable quantities of water. Ground water may occur
under either nonartesian or artesian conditions. Where the upper
surface of the zone of saturation, called the water table, is free
to rise and fall it is said to be nonartesian. Where the water is
confined in a permeable bed between less permeable beds, so that
its surface is not free to rise and fall, it is said to be artesian.
The term artesian is applied to ground water that is confined
under sufficient pressure to rise in wells above the top of the
permeable bed that contains it, though not necessarily above the
land surface. These less permeable beds are called confining beds.
The height to which water will rise in a tightly cased artesian
well is called the artesian pressure head. The imaginary surface
coinciding with the water levels of artesian wells is called the
piezometric surface. This surface is generally represented on a
map by contour lines that connect points of equal altitude of the
pressure surface. Water in an artesian aquifer moves from areas
of high artesian pressure toward areas of lower artesian pressure,
at right angles to the contour lines representing the piezometric
surface. Where the contour lines enclose an area of high water
levels (high artesian pressure), the flow is away from the area on
all sides. The artesian aquifer is being replenished in such an area.
Conversely, where the contour lines enclose an area of low water
levels, water is flowing into the area from all sides and is being
discharged from the aquifer. Areas in which aquifers are re-
plenished are called recharge areas; areas in which water is lost
from aquifers are called discharge areas.
NONARTESIAN AQUIFER
CHARACTERISTICS
In Polk County ground-water supplies are obtained from four
different aquifers, which were first recognized by Matson (Matson
and Sanford, 1913, p. 389). The uppermost of the four aquifers is
in the unconsolidated sand and clayey sand at, and just below,
land surface. These sands cover the entire county and, together
with the underlying coarse plastics where present, form the ion-






REPORT OF INVESTIGATION No. 44 79

a:tesian aquifer. The aquifer is used for domestic supplies and
for irrigation purposes requiring relatively small amounts of wa-
er. Tubular wells in this aquifer range from 11 to 4 inches in
diameter and from 7 to 35 feet in depth; there are also a few dug
ells and pits in use. Hand (pitcher) Pumps are commonly used
for domestic purposes, and gasoline-driven suction pumps are
used for irrigation. The irrigation wells usually do not produce
more than 20 to 30 gpm (gallons per minute), though several are
known to produce 100 gpm or more.
Wells are commonly constructed by driving small-diameter
pipe into this aquifer. The sand is then cleaned from the pipe, and
the well is deepened by water-jetting. There are very few dug,
sand-point, screened, or gravel-packed wells in the county. Wells
in the aquifer, as locally constructed, rarely retain their original
depth because the loose sand will not stand in the walls of an
open hole.
The thickness of the aquifer differs widely over the county,
and generally ranges from a few inches to 250 feet. However, ex-
treme thicknesses of 300-600 feet or more are reported along the
eastern side and on the crest of the Lake Wales ridge (fig. 4,
wells 755-134-1, 801-136-2, 818-140-1, 820-140-1). Clay content,
and hence porosity and permeability, likewise differ widely over
the county.
Figures 13 and 14 show the water levels in, and the locations
of, some of the nonartesian wells in the county. Though a great
number exist, there were not enough to provide the amount of
control necessary for a reasonably accurate map of the water
table of the entire county.
WATER-LEVEL FLUCTUATIONS
During the course of this investigation, water levels were
measured periodically in several wells in the nonartesian aquifer,
and continuous recorders were installed on others. Hydrographs
of representative wells in this aquifer are shown in figure 15.
The well illustrated in figure 15 is a part of the permanent net-
work of observation wells maintained in the state, and records of
the water levels have been previously published in Water-Supply
Papers of the U.S. Geological Survey under the well number Polk
47. Additional water-level data from wells in this aquifer in Polk
County have been previously published (Stewart, 1963, table 4).
Water-level fluctuations in this aquifer are due to (1) recharge
by rainfall, and (2) discharge by natural gravity flow down gra-



















































Figure 18. Water-table contour of the Lake Parker area, June 25-30, 1956.


_ __ __ ___ __ _.






REPORT OF INVESTIGATION NO. 44


m I 1 \ T .oA420.O ,- ,, ,<,Y
0 i iiei^t fT^I 1" "- '\ If.... 1 d.19 :0
3I I,,T \ EXPLANATION
i. : ,. i ., A ,', ,COUNTY. "1". V i














Figure 14. MIap showing water levels in selected wells penetrating the
dient to akes and streams, evaotransiration, downward ss









into underlying aquifer, and pumping from wells. None of the
Water-level decline due to downward loss or to natural lateral







gravity flow cannot be readily distinguished on the hyd ro graphs.o
VIE POLR C FUNI
COUNTY
IT M Cm 0 U N 7' 'N IGHITR1" M'-'-i i' -' ----- -

Figure 14. Map showing water levels in selected wells penetrating the
nonartesian aquifer (October 29, 1959 to February 4, 1960).
dient to lakes and streams, evapotranspiration, downward loss
into underlying aquifers, and pumping from wells. None of the
wells illustrated here are affected significantly by pumping.
Water-level decline due to downward loss or to natural lateral
gravity flow cannot be readily distinguished on the hydrographse
Generally water levels in wells on topographic high areas or
slopes will decline at greater rates from these causes than will
wells located low on topographic slopes or relatively flat locations.
Recharge is reflected by rising water levels, and the rate and
amount of rise is determined by the amount of rainfall, the
porosity and permeability of the aquifer, and other factors.
The range of fluctuation in nonartesian wells differs widely
over the county. The records of six wells, including those shown
:n figures 15 and 30-32, show net changes of 5.5 to 12.7 feet from
highest to lowest levels of record in individual wells. The greatest
totall annual fluctuation ranged from 4.3 to 9.6 feet in individual
wells.






FLORIDA GEOLOGICAL SURVEY


114

S113







10







107
o -l- |

















IO6 -Well 81-136-2, near Haines City
(Nonortesion aquifer)
105
1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
Figure 15. Hydrograph showing fluctuations of the water table in a well
c108 -- -

* 10 7 --- --- -- --- --- -- --- --- -V --- --- --


o 106 -- Well 810-136-2, near Haines City
(Nonartesion aquifer)

1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
Figure 15. Hydrograph showing fluctuations of the water table in a well
near Haines City (810-136-2) in the nonartesian aquifer.


UPPERMOST ARTESIAN AQUIFER
The pebble phosphate deposits that immediately underlie the
surficial sands of the Lakeland-Auburndale area form an artesian
aquifer of undetermined thickness and areal extent which is re-
ferred to as the "uppermost artesian aquifer" in this report. The
aquifer is in the coarse, sandy, phosphatic gravel zones (matrix)
of the phosphate deposits, and is confined above by the heavy
dense clays of the Bone Valley Formation, and below by clays
which may be either of the Bone Valley or Hawthorn Formations.
The few wells penetrating this aquifer are located on the lowland
between Lakeland and Auburndale, and are similar in construc-
tion to wells in the nonartesian aquifer. Near Saddle Creek the
piezometric surface of this aquifer is near the level of the water
table (figs. 13 and 14). Generally, however, it is 3 to 6 feet below
the water table.






REPORT OF INVESTIGATION NO. 44


In the southern part of the pebble phosphate fields (Bartow-
Homeland-Ft. Meade, fig. 4) the aquifer may be more productive
because it is generally thicker and coarser. In that area, the
piezometric surface may be intimately related to the nonartesian
aquifer because the upper confining bed is more porous than in
the Saddle Creek area. Well data from the southern part of the
mining area are very few. Though well data are lacking, similar
artesian conditions may exist elsewhere in the county in the sands
and clays generally overlying the limestone surface. Such occur-
rences may be of local nature and unrelated to the geologic units
present in the Saddle Creek-Peace River mining area.
Water-level observations made during the drilling of deep wells
in the Lakeland area indicate that the piezometric surface of this
aquifer is higher than that of the aquifers below it.


SECONDARY ARTESIAN AQUIFER
CHARACTERISTICS
The secondary artesian aquifer which is formed in the lime-
stone members of the Hawthorn Formation is used much more
than either of the two aquifers previously described. It is con-
fined above by the clays in the upper part of the Hawthorn. For-
mation or the lower part of the Bone Valley Formation, and is
confined below by the blue clay of the Tampa Formation.
The aquifer is present over much of the county south of Polk
City. Along much of the northern boundary the limestones are
10 feet or less in thickness, and are soft and deeply weathered.
Permeabilities in such locations (wells 805-153-2, 805-156-1,
806-156-1) are very low. Isolated areas in which these limestones
have been removed by erosion exist miles south of the general
boundary indicated.
An aquifer within the Hawthorn Formation is also reported in
recent investigations of other parts of central Florida. Bermes
(1958, p. 19-20) refers to this aquifer as the "Shallow artesian
aquifer" in Indian River County; Peek and Anders (1955, p. 20),
and Peek (1958, p. 26), report a separate artesian aquifer in these
limestone units in Manatee County; Klein (1954, p. 22) likewise
reports a separate artesian aquifer in the limestones of the Haw-
thorn Formation in the Naples area of Collier County. All of
these authors find that the pressure head in these aquifers is 5 to
20 feet below that of the underlying Floridan aquifer, in the areas






FLORIDA GEOLOGICAL SURVEY


concerned. Peek and Anders (op. cit.) note that the difference in
head appears to decrease eastward in Manatee County.
In Polk County many wells draw water from this aquifer in
the lowland of Saddle Creek and the Peace River, and these are
used for domestic supplies and truck-farm irrigation Others,
used almost exclusively for domestic supplies, are scattered over
the southern two-thirds of the county. Locally, a few large di-
ameter citrus irrigation wells produce large quantities of water
from this aquifer. Such production is possible because these wells
penetrate large solutional caverns in the limestones. Generally
wells in this aquifer range from 11/4 to 6 inches in diameter and
from 30 to 75 feet in depth. Wells that utilize this aquifer in the
southern part of the county and in the ridge sections are con-
siderably deeper because of the dip of the formations and the
altitude of land surface. The casing of wells drilled into this
aquifer usually terminates in the uppermost part of the limestone,
but in some wells it is driven only into the clays of the overlying
formations. This latter practice may lead to eventual collapse of
the clays and clogging of the wells.
In lowland areas, water levels in wells open only to this aquifer
are generally 5 to 10 feet below the water table and are also below
water levels in the uppermost artesian aquifer where it is present.,
In the ridge areas the water level may be more than 100 feet
below the water table because of the higher altitude of land sur-
face. Figure 16 shows hydrographs of wells which are open only
to the secondary artesian aquifer. Well 744-131-1 is one of the
permanent network of observation wells in use by the U.S. Geo-
logical Survey, and annual water-level data have been previously
published in Water-Supply Papers of the Survey under the well
number Polk 51. Additional water-level data has been published
by Stewart (1963, table 6). The hydrographs from widely sepa-
rated wells in this aquifer correlate closely, and the very local
effect of pumping causes only slight variations in the general pat-
tern of the water-level fluctuations.
Locally the secondary artesian and the Floridan aquifers are
in direct contact or relatively better hydraulic connection through
faulting, jointing, buried sinks, areas of artesian flow, or areas
in which the clay of the Tampa Formation is absent. The water
level of the secondary artesian aquifer will equal or closely ap-
proach that of the Floridan aquifer in these areas. However, a
short distance from such areas the secondary aquifer resumes its
separate identity.






REPORT OF INVESTIGATION NO. 44


0>
96

1954 1955 1956 1957 1958 1959

E
94



E 90

88
ss In II

86 -


84
82-
0
82 -- -- -I- -- -



Well 744-131-1, near Frostproof
(Secondary artesian aquifer)
1949 1950 1951 [1952 1953 1954 1955 1956| 1957 1958 1959

Figure 16. Hydrographs showing fluctuations of the piezometric surface
in a well near Lakeland (803-153-18) and a well near Frostproof (744-131-1)
in the secondary artesian aquifer.


THE PIEZOMETRIC SURFACE
Figure 17 is a map of the piezometric surface of the secondary
artesian aquifer in the lowland along Saddle Creek in June 1956.
The large cones of depression around the springs at points E, F,
and G were caused by discharge from the aquifer in mine pits
operating at the time of mapping. The map was made near the
end of a period of extended drought (1954 through 1956).
Much of the area between Saddle Creek and the western
branch of Saddle Creek, south of the springs at point E, is a
mined-out area, used as a water-storage area in June 1956. Lime-






FLORIDA GEOLOGICAL SURVEY


Figure 17. Piezometric-contour map of the secondary artesian aquifer of
Lake Parker area (June 1956).


stone of the Hawthorn Formation was exposed at many places
in the floors of these pits during mining operations. Artesian
springs which issued from the limestone during mining operations
have been impounded. Water was pumped from the operating pits
and was either used in mining operations or stored in the aban-
doned pits. Mining in the Saddle Creek mine (south of point E)
ceased January 10, 1957. Mining in the vicinity of the more
northerly springs ceased some months later. By February 1960,
mining had shifted generally to the north and east of the spring
sites shown and was in progress north of 804-151-7. Mining in the
Orange Park mine, east and northeast of 807-154-2, began May
5, 1957, and was still in progress in February 1960.
The effect of mining, and the cessation of mining, on a well
(803-153-18) in this aquifer is shown by the hydrograph in figure
16. The areal effect of the cessation of mining in the Saddle Creek
area, and the generally concurrent return of normal rainfall, is
shown by figure 18. Water levels on the ridge areas rose 3- to 5
feet over those of June 1956, while in the lowlands along Saddle


a- rrw ;j, G


.. .-;,I, K S.-. J





REPORT. OF INVESTIGATION No. 44 87





... ....-

















Figure 18. Piezometric-contour map of the secondary artesian aquifer in
Lake Parker area (October 1959 to February 1960).


Creek water levels rose as much as 15 feet, and 10-foot increases
were common.
Well 744-131-1 (fig. 16) located in Frostproof is a nonmining
area far beyond the effects of mine pumping. The net effect of

in well 744-131-1, and 13 feet in 803-153-18.
.14


5-r ---- ----













In preparing figure 18 a number of revisions of an earlier map
_ )loms i) U : G*Wz9-1 S-7 _y-119y byKGS Sle J






Figu(Stewart, 1956. Piezometric-contour map because the secondary artesian aquifer in
tesian aquifer area (October 1959actually cover the entire area of the map,1960).

Creek water levels roll thought. These as muchanges 15 feet, and 10-foot increases
were common.




ell 744-131-1 (fig8. Because of intense erosion an16) located possible extensive mis a nonminingr fault-
ing,area far beyond the limestoneffects of the Tampa Formation is locally tinghe net effect of





most limestone. The Hawthorn is very thin in a few wells pre-
generviously thought to be rainfall may in Hawthorn, and which are now
tiveknown to be multi-aquiferrise of water levels of the wells, open to both the secondary andet
underin well 744-131-1,ridan artesian aquifers.803-153-18.
In preparing figure 19 is a map showing altitudevisions of water levels in the
aquifeart, 1956,ing the 1) inter necessary because t95960, he such data is
tesian aquifer did -not actually cover the entire area of the map,
as originally thou ght. These changes are made in figures 17 and
18. Because of intense erosion and possible extensive minor fault-
ing, the limestone of the Tampa Formation is locally the upper-
most limestone. The Hawthorn is very thin in a few wells pre-
viously thought to be entirely in Hawthorn, and which are now
known to be multi-aquifer wells, open to both the secondary and
underlying Floridan artesian aquifers.
Figure 19 is a map showing altituIdes of water levels in the
aquifer during the winter months- of 1959-60, where such data is






FLORIDA GEOLOGICAL SURVEY


Figure 19. Piezometric-contour map of the secondary artesian aquifer
(October 1959 to February 1960).

available in the county. The map also shows the approximate
northern extent of the aquifer. Water levels declined from 0.5 to
3.4 feet in eight observation wells during the period. The map
shows that an extensive trough exists in the piezometric surface
along the Saddle Creek-Peace River valleys, and that it passes
between several significant piezometric highs, which indicate re-
charge areas. A very extensive piezometric high underlies the
west flank of the Lakeland ridge, and occupies much of the south-
western part of the county. Another high underlies a broad flat
area south of Lake Buffum. A smaller high area is located on the
ridge north of Lake Ariana.

AREAS OF ARTESIAN FLOW
Flowing artesian wells in this aquifer existed as late as 1948
in the general vicinity of well 803-152-2, about a half a mile
northeast of the U.S. Highway 92 bridge over Saddle Creek. Water






REPORT OF INVESTIGATION NO. 44 89

levels in that area were reported to have been about 2 feet
above land surface in 1948, but they had dropped to about 11 feet
below the surface by 1956. In 1959 they closely approached land
surface for brief periods, and generally were about 2 feet below
land surface. The area of artesian flow apparently extended about
three-fourths of a mile on either side of Saddle Creek; its north-
south extent is unknown. The area of flow was described by
Sellards and Gunter (1913, p. 263), and Matson and .Sanford
(1913, table facing p. 390) reported a flowing well in this area.
It is likely that flowing wells could be obtained along the valley
of the Peace River from the southern county line north midway
to Lake Hancock. Observations of ground-water leakage in the
secondary aquifer in the vicinity of well 745-147-1 (fig. 19), in
August 1958, showed that water levels rise rapidly toward high
ground up the valley wall, and the area of artesian flow may be
less than 100 feet wide in some places. Progressively lower flow
and head may be expected upstream; and in the vicinity of Lake
Hancock, wells probably would only flow during brief periods of
very high ground-water levels.

WATER-LEVEL FLUCTUATIONS
The range of water-level fluctuations in wells in the aquifer
differs widely over the county. The causes of the greatest fluctua-
tions are due to recharge and to pumping from the aquifer. The
hydrographs of wells show net changes from highest to lowest
water levels of record of 9.4 to 24.5 feet in individual wells. The
maximum annual fluctuation in these wells ranged from 7.3 to
17.9 feet.

FLORIDAN AQUIFER
CHARACTERISTICS
The principal aquifer in the area of this investigation is the
Floridan aquifer, which consists of a series of limestones that
range from middle Eocene to Miocene in age. It is an artesian
aquifer and is the source of all major public, industrial, and ir-
rigation water supplies in the county. The name Floridan aquifer
was introduced by Parker (Parker and others, 1955, p. 189) to
include "parts or all of the middle Eocene (Avon Park and Lake
City limestones), upper Eocene (Ocala limestone), Oligocene
(Suwannee limestone), and Miocene (Tampa limestone and per-






FLORIDA GEOLOGICAL SURVEY


meable parts of the Hawthorn formation that are in hydrologic
contact with the rest of the aquifer." According to Cooper,
Kenner, and Brown (1953, p. 17), this aquifer "underlies almost
all of Florida, the coastal area of Georgia, and the southeastern-
most parts of South Carolina and Alabama."
In Polk County the youngest (uppermost) member of the
Floridan aquifer in a few areas is the limestone units of the
Tampa Formation. In the northern and eastern parts of the
county, the uppermost limestone member of the Floridan aquifer
is the Ocala Group, most commonly the Crystal River Formation
(fig. 5). In the remainder of the county the Suwannee Limestone
is the upper member of the aquifer, although local thin limestones
of the Tampa may be found. Wells penetrating the Floridan
aquifer range from 2 to 30 inches in diameter and from 60 to
1,400 feet in depth.
Wells that are open to both the secondary artesian aquifer
and the Floridan aquifer are multi-aquifer wells. They range from
3 to 12 inches in diameter, and from 70 to 850 feet in depth. Most
of them are small diameter and are used for domestic and small
irrigation requirements. Water levels in multi-aquifer wells are
about the same altitude as those in wells open only to the Floridan
aquifer. This is due to the higher permeability of the Floridan,
aquifer.
Unklesbay (1944, p. 13-14) reports that in Orange County the
formations constituting the Florida aquifer act hydrologically as
a unit, and that water levels in the upper part of the aquifer are
the same as those in the lower part. Bermes (1958, p. 21) reports
that the aquifer also functions as a hydrologic unit in Indian
River County, on the Atlantic coast. Stewart (1959, p. 33) re-
ported similar conditions in northwestern Polk County.
Peek and Anders (1955, p. 15), and Peek (1958, p. 26), report
the existence of low permeability zones in the aquifer which re-
tard vertical movement of water. Wyrick (1960, p. 27-28) shows
extensive stratigraphic barriers within the aquifer in Volusia
County. Bishop suggests that significant stratigraphic barriers
also exist in the aquifer in Highlands County.
Table 7 is a compilation of water-level measurements made in
Polk County. These data do not show significant changes in static
water levels with increased depth of drilling in the Floridan
aquifer. This indicates that the various formations comprising
the aquifer have a free hydraulic connection, and that they func-
tion as a single aquifer. The changes actually observed and re-






REPORT OF INVESTIGATION NO. 44


corded are caused by (1) measurements being made immediately
after drilling or bailing and before the water has recovered to a
static level; (2) penetration of significant solutional features;
(3) measurements made when open-hole portion of the well is
only a few feet (805-155-2); or (4) well terminates in a local zone
of very low permeability (as in the 210-219 foot interval of
803-156-11 and in the Lake City and Oldsmar zones of 801-200-3).
The bottom of the Floridan aquifer, and hence its thickness,
has not been previously determined. At the present time only a
few wells penetrate the Lake City Limestone and deeper forma-
tions in this county. However, the existence of highly soluble gyp-
sum and unaltered anhydrite, in the Oldsmar, Lake City and
lower part of the Avon Park Limestones, discussed earlier in this
report, show conclusively that there has been no appreciable
ground-water circulation in these units since their deposition.
Vernon (1951, p. 87, 90-91) indicates that these minerals are
common in the Lake City and Oldsmar, and (op. cit., p. 82-85) in
the underlying Cedar Keys Limestone (Paleocene) and upper part
of the Lawson Limestone (Upper Cretaceous). Hence, the bottom
of the Floridan aquifer in the Lakeland area, and probably most
of Polk County, coincides with the base of the Avon Park Lime-
stone. It appears that this may also be true in many other parts
of peninsular Florida.

THE PIEZOMETRIC SURFACE

Figure 20 is a contour map of the piezometric surface of the
Floridan aquifer during the period October 1959-February 1960.
During the period of measurement water levels in the aquifer
were recorded continuously in seven wells, and measured periodi-
cally in 17 others. The net changes observed during the measure-
ments are indicated on the inset map on figure 20.
With the exception of about 10 city wells, all of the pumping
wells shown on the map are industrial or citrus irrigation wells
being pumped for long periods of time. They are therefore capable
of exerting great influence on the water level of surrounding
areas. The areas of drawdown shown around the pumping wells
are approximate in most instances, and are intended to illustrate
areas of generally heavy pumpage.
The piezometric surface of the Floridan aquifer in Polk
County is a very irregular dome-shaped surface, and is highest in
the north-central part of the county (fig. 20). The dome is elon-