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 Copyright
 Front Cover
 Florida State Board of Conserv...
 Transmittal letter
 Table of Contents
 Abstract
 Introduction
 Geology
 Ground water
 Salt-water contamination
 Summary and conclusions
 References
 Table 5. Chemical analysis...
 Table 6. Water-level measureme...
 Table 7. Logs of selected...
 Map


FGS







STATE OF FLORIDA

STATE BOARD OF CONSERVATION

Ernest Mitts, Director

FLORIDA GEOLOGICAL SURVEY

Robert 0. Vernon, Director



REPORT OF INVESTIGATIONS NO. 18




GROUND-WATER RESOURCES OF

MANATEE COUNTY, FLORIDA


By
Harry M. Pcek
U. S. Geological Survey




Prepared by the
UNITED STATES GEOLOGICAL SURVEY
in cooperation with the
FLORIDA GEOLOGICAL SURVEY
BOARD OF COUNTY COMMISSIONERS OF MANATEE COUNTY
and the
MANATEE RIVER SOIL CONSERVATION DISTRICT


TALLAHASSEE, FLORIDA
1958






!' */. "/





FLORIDA STATE BOARD

OF

CONSERVATION


LEROY COLLINS
Governor


I. A. GRAY
Secretary of State



J. EDWIN LARSON
Treasurer



THOMAS D. BAILEY
Superintendent of Public Instruction


RICHARD ERVIN
Attorney General



RAY E. GREEN
Comptroller



NATHAN MAYO
Commissioner of Agriculture


ERNEST MITTS
Director of Conservation





LETTER OF TRANSMITTAL


Oda qeyloaical cSatvemj

Tallahassee

December 15, 1958



Mr. Ernest Mitts, Director
Florida State Board of Conservation
Tallahassee, Florida

Dear Mr. Mitts:

I am forwarding to you a report entitled, GROUND-WATER RE-
SOURCES of MANATEE COUNTY, FLORIDA, which was prepared
by Harry M. Peek, Geologist with the U. S. Geological Survey. This
work was done in cooperation with the Florida Geological Survey, the
Board of County Commissioners of Manatee County and the officials
of the Manatee River Soil Conservation District. It is recommended
that this report be published as Report of Investigation No. 18.

The rapid development and expansion of the coastal areas of Manatee
County combined with increased irrigation of truck farms, cattle lands
and citrus groves, have multiplied the problems of obtaining adequate
supplies of water which meet the quality demands of the various com-
peting interests. This study contributes the needed data for a wise
development of the water resources of the area.

Respectfully submitted,
ROBERT 0. VENON, Director





























Completed manuscript received
April 30, 1958

Published by the Florida Geological Survey
Rose Printing Company, Inc.
Tallahassee, Florida
January, 1959






TABLE OF CONTENTS
Page
Abstract .....-...................-......-........... ....-- .................................................................. 1
Introduction ...........................-.............. ..........................................---- .. ---- 2
Purpose and scope of the investigation ............................................................... 4
Acknowledgments ...............................................................---.....................--........--------..... -- 5
Previous investigations -------........------..........................................................------------------...--..---.......... 5
Well-numbering system ....................................................-..---....-- --------- -------- 6
Geography ........................................................................................... ------------
Climate ..........................--..-...-...-....--....--------.......-------------........................................................---------.. 6
Physiography ..........-.....-............................................................. ....---- ------- 9
History ....................................... ....................................---- ...............................--------------- 11
Population ..............---------------.---...................-...................-----------------.................................................. 12------------12
Industry ..........------.........---.--------......----------.............----...................-------------.....................-........... 12
Transportation ....----------------.................................--...........................----.............-----.----........------........ 14
Geology ..............-............-----------.-....................................------...........---------------------------------------------------..... 14
Pre-T ertiary rocks .................................................................................... ........ 14
T ertiary system ................................................................................................... 14
E ocene series ............................................................................................... 14
Avon Park lim estone ........................................................................... 14
O cala group ......................................................................................... 16
O ligocene series ........................................................................................... 17
Suw annee lim estone ........................................................................... 17
M iocene series ..................................................................................... ........... 18
Tam pa form ation ................................................................................. 18
Hawthorn formation ........................................................................... 21
Pliocene series ..................................................................................... ........ 21
Pleistocene series ......................................................................................... 22
Ground water .....-..-......--------................................--.....................................-----...------------------.--. 22
Principles of occurrence .......--..-.........-----...................--.-----..........................-------------------- 22
Ground water in Florida .----................---- ........--------------....-------------------------------- 28
Artesian water ..........................................-......-............................................. 24
Piezometric surface .....................--...............................................----------...... 24
Ground water in Manatee County .--------------...............--......----.............................-------.---- 24
Artesian water ......................................................----------.................................... 26
Current-meter exploration ...--...........................-------.----..............................-------------.. 27
Artesian head -..-...--.........................................................-------------------------------- 883
Piezometric surface ................................. .. ..................... .............44
Depth to water level below land surface ........................................... 47
Temperature --.--.-------......-....................................--..------------..................----------. 47
Use of water-------- ..........-....................-............---.......----..........--..------....---..-------............ 49
Quantitative studies .......-----------------..............................-..........--------------------------------- 49
Pumping test ..........-- .............--........................................................... 50
Theoretical drawdowns ..................................-.................... .------........ .. 52
Quality of water -...------...-.......-............--------------------------------------------------------------... 56
Constituents and properties -----.....--..-...-...........----...-....................................... -----------------56
Calcium ....................................... ........................-------...........................--... 56
Magnesium ....-------------..................................--......................................---.....----------...........-------. 59
Sodium and potassium -.................-----....-.................................------....------........--..---- 59
Bicarbonate .......---............-----------....................................................................----------- 59
Sulfate -...-...-...-..........................---------..--.....-..-..........................................----------------....----.--...... 59
Chloride ....--------------................-....-..................................... .......................... 59







Iron 2.. ..-... .. ....-.....- ... ............................................................ 62
Fluoride .... ......... ........ ........ ...... .. ......................................... ..... 62
Dissolved solids ... ........- ............................................................. 02
Hardness ....-..----------......------------------------..................................-...--.................. 68
Specific conductance .... ................... .............. ............................------------..-- 08
Hydrogen sulfide ....-------... ---------....... -............... -----...... ............. .................. 68
Hydrogen-ion concentration (pH ) .................................................... 68... 8


Salt-water contamination

Summary and conclusions

IRHefrences


. .. .... .... .... ..... .... ........................ ..... ........... 7 1

........................--------................................ 76

.... ....------ ...............................------... 78






















































vi






ILLUSTRATIONS
Plate Page
1 Map of western Manatee County showing locations of wells........... In pocket
Figure
1 Map of the Florida Peninsula showing the location of Manatee County ...... 3
2 Map of eastern Manatee County showing locations of wells ........................... 7
3 Precipitation and temperature at Bradenton ...............................................------------------ 8
4 Map of Manatee County showing the Pleistocene terraces ........-................. 10
5 Population growth in Manatee County and the cities of Bradenton
and Palmetto, 1890-1950 ......-.............................................................-........... 13
6 Cross sections showing the geological formations penetrated by
water wells in M anatee County ..... ................................. ....................... .. 16
7 Structure-contour map of the top of the Suwannee limestone in
Manatee County ......................................--------------------.........-...............................-----............. 19
8 Structure-contour map of the top of the Tampa formation in
M anatee County ................................................................................................. 20
9 Map of the Florida Peninsula showing the piezometric surface ---......------.. 25
10 Graphs showing data from well 27-28-2, seven miles southeast of
Bradenton ..............................................................................-----....-..................-----------..-- 27
11 Graphs showing data from well 28-29-8, six miles southeast of
Bradenton ....-........--.....-......-....---------------...................-.............-.....--.--------................-...........------........--... 28
12 Graphs showing data from well 28-14-4, near Cortez ........................................29
13 Graphs showing data from well 29-29-4, five miles east of Bradenton .......... 80
14 Graphs showing data from well 30-28-1, seven miles east of Bradenton ........ 31
15 Graphs showing data from well 88-32-5, five miles northeast of Terra Ceia.... 32
16 Graphs showing data from well 29-37-10, four miles west of Bradenton ....-.. 34
17 Hydrograph of well 26-18-1 and rainfall at Bradenton ...--................---.......-----...---..- 36
18 Hydrographs of wells 27-36-3, 28-31-1, and 31-34-6 ..............-...---.........----- .------..... 37
19 Hydrographs of wells 17-11-1, 24-30-1, 26-41-2, 28-23-1, and 29-37-7 .-..-....---. 38
20 Graphs showing relation between water levels and chloride content of
water in wells 23-38-3, 28-41-4, and 29-40-10 .....-......--..................-------------......-......-..-....-- 39
21 Graphs showing relation between water levels and chloride content of
water in wells 27-34-1, 27-38-7, and 27-41-1 .--......------..-.........-.........-..-...-................--.... ------40
22 Graphs showing relation between water levels and chloride content of
water in wells 29-42-8, 81-37-12, and 83-35-4 .--....----------...........-...--..-..........-....-....--...-..--. 41
28 Graphs showing relation between water levels and chloride content of
water in wells 80-39-11, 31-43-3, and 31-44-38 ...................................................42
24 Effects of earthquakes and changes in barometric pressure on the water
level in well 26-18-1, 12 miles northwest of Myakka City ..........--------....-......-....-...-- 48
25 Map of Manatee County showing the piezometric surface in
September 1954 -....--.---..........--...........-..-.................................................----....--.........---....--..- 45
26 Map of Manatee County showing the piezometric surface in June 1955 ...... 46






27 Map of Manatee County showing the area of artesian flow and the
depth to water in June 1955 ..-..-------------.........-------..................---------............................................- 48
28 Sketch of pumping-test site, showing location of pumped well in
relation to observation wells ................... ............................. ......... ......-........... 50
29 Graphs showing drawdown and recovery of water levels in observation
wells during pumping test .......................-................................. ---.................... 51
'30 Logarithmic plot of drawdowns in observation wells versus t/r ..............------ 58
31 Logarithmic plot of recovery in observation wells versus t/r ................-----.... 54
32 Semilog plot of recovery versus t for well 84-30-3, seven miles
northeast of Bradenton .---. -------.. --------... --......---.............--..----------...--.......-. 55
33 Graph showing theoretical drawdowns in the vicinity of a well being
pumped at a rate of 1,000 gpm for selected periods of time ....------.......-............. 57
34 Map of Manatee County showing wells sampled for chemical analysis
and location of line A-B in figure 44 .----..---------------.................................................. 58
35 Map of western Manatee County showing sulfate content of water from
wells that penetrate the Suwannee limestone and older formations .-..........------.. 60
36 Map of western Manatee County showing sulfate content of water
from the Tampa formation .. ------------------..... ...........................---------............ 61
37 Map of western Manatee County showing chloride content of water from
wells that penetrate the Suwannce limestone and older formations ...........- 63
38 Map of western Manatee County showing chloride content of water
from the Talampa form action .......................................................................... ........ 64
39 Map of western Manatee County showing chloride content of water
from the Hlawthorn and younger formations .--------..-..--....-...-...----..-------........ 65
'10 Map of western Manatee County showing concentration of dissolved solids
in water from wells that penetrate the Suwance limestone and older for-
ations .. ..... ....-----------....... -- --------.......... ..-........-............ 66
41t Map of western Manatee County showing concentration of dissolved
solids in water from the Tampa formation -- .---..-------...---.......-------.......-... 67
42 Map of Manatee County showing hardness of water from wells that
penetrate the Suwannee and older limestones ....------.....--------......--------................. 69
43 Map of Manatee County showing hardness of water from
the Tampa formation ----------..... ..................-------------------......---... 70
41 Graph showing the principal constituents of water from selected
wells along line A-B in figure 34 ..--------..--....-------............. --------------........... .... 72
45 Graph showing data from well 27-36-1, four miles southwest
of Bradenton ..- -- ---------... ..................................... ---------------- 74
46 Graph showing chloride content and temperature of water from well
29-10-3, two miles north of Cortez --.-..---.------------------............. ........... ........ 75
Table
1 Pleistocene terraces and shorelines in Manatee County ................................ 9
2 Agricultural use of land in Manatee County in 1954 .--------.....................................-- 12
3 Geologic formations of Manatee County ---..... ..................................................... 15
4 Stratigraphic nomenclature of the upper Eocene in Florida ............................ 17
5 Chemical analyses of water from wells in Manatee County ............................ 80
6 Water-level measurements ...--.....---..............-------------------.......................................................... 85
7 Logs of selected wells in Manatee County ..................................................... 89
viii







GROUND-WATER RESOURCES OF
MANATEE COUNTY, FLORIDA

ABSTRACT

Manatee County comprises an area of about 800 square miles adjacent
to the Gulf of Mexico in the southwestern part of peninsular Florida.
Deposits of sand, limestone, and shells, mainly of Pleistocene age, but
probably partly of Pliocene age, are exposed at the surface throughout
most of the county. These range in thickness from a few feet to about
90 feet. They are underlain by interbedded marl, limestone, and sand
of the Hawthorn formation of middle Miocene age. The Hawthorn
formation is underlain, at depths ranging from about 175 to 350 feet
below sea level, by a series of limestones of Tertiary age which have
a total thickness of more than 4,000 feet. The upper part of the limestone
section consists of the Avon Park limestone of late middle Eocene age,
the Ocala group' of late Eocene age, the Suwannee limestone of Oligo-
cene age, and the Tampa formation of early Miocene age.
Usable quantities of ground water are obtained in the county from
all formations penetrated by wells. Small supplies for domestic use are
obtained from the surficial deposits of sand and shells, which contain
water under nonartesian conditions. Most domestic supplies, however,
are obtained from the permeable beds in the upper part of the Hawthorn
formation and from younger formations in which the water is under a
slight artesian pressure.
The Suwannee limestone and Tampa formation are the principal
sources of artesian water. All the large industrial, irrigation, and public
supplies are obtained from them, but many domestic and small irrigation
supplies are obtained from permeable beds in the Hawthorn formation,
which serves as a confining bed for the water in the underlying limestones.
Records of the fluctuations of artesian head show that the withdrawal
of large quantities of artesian water causes an extensive lowering of the
piezometric surface. During periods of heaviest withdrawal, the piezo-
metric surface declines at least four or five feet throughout the county
and as much as 10 feet at some places. The magnitude of the seasonal
fluctuations has increased and a progressive decline in the artesian head

'The stratigraphic nomenclature used in this report conforms to the usage of
the U. S. Geological Survey with the following exceptions: the Ocala limestone is
herein referred to as the Ocala group, and the Tampa limestone is referred to as
the Tampa formation. These exceptions are made in order to conform to the nomen-
clature used by the Florida Geological Survey.






FLORIDA GEOLOGICAL SURVEY


has occurred in some parts of the county since about 1948, because of an
increase in water use.
Determinations of the chloride content of the artesian water indicate
salt-water contamination in a zone about 3 to 10 miles wide along the
coast. The degree of contamination increases with depth and seaward.
Throughout most of the zone, the water in the Tampa formation contains
less than 250 parts per million (ppm) of chloride and is suitable for
most purposes, but some wells in the vicinity of Palma SolaBay yield
water from the Tampa formation containing more than 400 ppm of
chloride. The chloride content of the water in the Suwannee limestone
is more than 2,000 ppm at some places but is generally less than 500 ppm.
The water in the Eocene formations along the coast is probably too
salty for most uses.
Periodic analysis of the water from many wells shows that the
chloride content varies with the seasonal fluctuations of artesian pressure
head. Some wells that show a progressive decline in artesian pressure
head also show a progressive increase in chloride content of the water,
indicating that significant declines in head result in upward movement
of salty water from the deeper formations. This upward movement is
probably retarded considerably by the beds of low permeability that
separate the principal water-bearing zones.
INTRODUCTION
Ground water is the principal source of fresh water for public, domes-
tic, agricultural, and industrial supplies in Florida. The increased use
of ground water in the State, resulting from the growth of population
and industry, has caused a large number of water-supply problems,
particularly in coastal areas where population and industry are concen-
trated. Most of the water-supply problems in these areas can be classified
as "salt-water" problems.
In much of the coastal area of southern Florida, a part or all of the
formations capable of yielding large quantities of water contain naturally
salty water. Thus, the problem in this area is one of finding supplies of
fresh water that are adequate to meet the increased demand and are
economically feasible to develop. The problem in other areas is to
protect present supplies from contamination by salt-water encroachment
from the sea or from underlying formations that contain naturally salty
water. Encroachment of salt water from either source occurs as a result
of excessive lowering of the fresh-water pressure head.
A large part of western Manatee County (fig. 1) is used for growing
winter vegetables and citrus fruits, and large quantities of artesian water








REPORT OF INVESTIGATIONS No. 18


Apotoolols iStole


. ip0 UMile


Figure 1. Map of the Florida Peninsula showing the location of Manatee County.


_~__






FLORIDA GEOLOGICAL SURVEY


are used for irrigating these crops. The large withdrawals of artesian
water for irrigation and for processing agricultural products result in a
considerable seasonal decline of the artesian head, particularly in the
western part of the county. This seasonal decline of artesian head has
increased in proportion to the increase in withdrawal of artesian water.
The progressive increase in seasonal decline of the artesian head
intensifies the danger of salt-water encroachment in the artesian aquifer.
The presence of salty water in the artesian aquifer in parts of the coastal
area of the county suggests that slight encroachment may already have
occurred. Recognizing this possibility, and in response to the concern
expressed by the farmers of the county, the Board of County Commis-
sioners and the Supervisor of the Manatee River Soil Conservation Dis-
trict requested the U. S. Geological Survey and the Florida Geological
Survey to make an investigation of the ground-water resources of the
county. As a result of this request, an investigation was begun in Decem-
ber 1950 by the U. S. Geological Survey in cooperation with the above
agencies.

PURPOSE AND SCOPE OF THE INVESTIGATION
The purpose of the investigation was to make a detailed study of the
geology and ground-water resources of the county, principally to deter-
mine whether salt-water encroachment had occurred or was likely to
occur. The investigation consisted of the following phases:
1. An inventory of more than 900 selected wells, to obtain information related
to the occurrence and use of ground water in the county.
2. A collection of data on water levels for use in determining progressive trends
and the magnitude of seasonal fluctuations, and in constructing maps show-
ing the altitude to which water will rise in artesian wells.
3. Determinations of the chloride content of water from about 750 wells, to
define the areas in which the ground water is relatively salty.
.I. Periodic determinations of the chloride content of water from selected wells,
to find the relation between salinity and artesian pressure.
5. A study of geologic conditions governing the occurrence and movement of
ground water.
f(. Exploration of selected wells with deep-well current meter, to determine
the depth and thickness of the principal water-bearing zones.
7. Chemical analyses of water samples from selected wells.
8. Studies to determine the water-transmitting and water-storing properties of
the water-bearing formations.
The field work of this investigation from December 1950 to January
1954 was done by R. B. Anders of the U. S. Geological Survey. An
interim report covering this part of the investigation was published in
March 1955 (Peek, H. M., and Anders, R. B., 1955). The field work from
January 1954 until the investigation was completed in December 1955






REPORT OF INVESTIGATIONS No. 18


was done by the author of the present report. The present report includes
most of the data from the earlier field work and report.
ACKNOWLEDGMENTS
Acknowledgment is made to H. 0. Kendrick, County Agent, and his
staff and to E. L. Ayers, County Agent during the first part of the
investigation, for the helpful assistance given throughout the investiga-
tion. I. H. Stewart of the Soil Conservation Service, U. S. Department
of Agriculture, and Fonzie Outlaw and L. Rhinehart of his staff, con-
tributed much valuable information and gave assistance in many ways
toward completion of the field work.
Appreciation is expressed to the well drillers who furnished informa-
tion and collected rock cuttings and water samples. These include:
Charles and Lowell Pemelman, W. Reddick, T. M. Shacklee, and Dale
Young, of Bradenton; C. D. Cannon, J. 0. Mixon, and E. Moran, of
Palmetto; E. E. Boyette, of Ruskin; J. P. Adams and R. Phillips, of
Sarasota.
Special thanks are due the many well owners for their cooperation
in contributing information and otherwise aiding the investigation.
PREVIOUS INVESTIGATIONS
No detailed investigations of the geology and ground-water resources
of Manatee County had been made prior to the present study. However,
several short studies were made, and the results have been published in
the reports of the Florida Geological Survey and the U. S. Geological
Survey. Some of the more informative reports are described below.
A report by Matson and Sanford (1913, p. 237, 254, 362-364; pl.5)
includes a section on the geology and water supply of Manatee County
and a table of selected well records. A report by Sellards and Gunter
(1913, p. 266-269; fig. 16) also includes a brief summary of the geology
and ground-water resources of the county and a map showing the area of
artesian flow.
A report on a reconnaissance investigation of several counties in the
State by Stringfield (19388, p. 8-5) contains a brief discussion of the
geography, geology, and ground water of Manatee County. Another
report by Stringfield (1936, p. 145, 164, 167, 170, 180, 182, 191, 192; pl.
10, 12, 16), which gives the results of a study of the artesian water of
the Florida Peninsula, contains water-level measurements and other data
on about 90 wells in Manatee County. The 1936 report also includes
maps of the Florida Peninsula showing the area of artesian flow, the
height above sea level to which water in the principal artesian aquifer
will rise in wells, and the areas in which water having a chloride content




FLORIDA GEOLOGICAL SURVEY


of more than 100 ppm is present at moderate depths.
The formations that crop out are briefly described in a report on the
geology of Florida by Cooke (1945, p. 138, 158, 157, 208, 223, 807). A
report by MacNeil (1950, pl. 19) describes Pleistocene shorelines in
Florida and Georgia and contains a map showing the general configura-
tion of these shorelines in Manatee County.
Chemical analyses of water from several wells and springs in Manatee
County are included in a report by Collins and Howard (1928, p. 220-
221) and a report by Black and Brown (1951, p. 77).
WELL-NUMBERING SYSTEM
The well-numbering system used in this report is based on latitude
and longitude. As shown in plate 1 and figure 2, the county has been
divided into quadrangles by a grid of 1-minute parallels of latitude and
1-minute meridians of longitude. The wells have been assigned numbers
according to their location within this grid. Each well number consists of
three parts: The first part is the latitude, in minutes, of the south side of
the 1-minute quadrangle, the second part is the longitude, in minutes, of
the east side of the quadrangle, and the third part is the number of the
well within the quadrangle. For example, the number 27-34-3 designates
the third well listed in the quadrangle bounded by latitude 27' on the
south and longitude 34' on the east. The degrees of latitude and longi-
tude are not included as a part of the well number because they are the
same for all wells in the county (fig. 1). Well locations are shown on
plate I and figure 2. Complete well descriptions, locations, and other
data are to be published as Florida Geological Survey Information Cir-
cular No. 19, and may be obtained for one dollar per copy.
GEOGRAPHY
Manatee County comprises an area of about 800 square miles adja-
cent to the Gulf of Mexico in the southwestern part of the Florida
Peninsula (fig. 1). It is bounded on the north by Hillsborough County,
on the east by Hardee and De Soto counties, on the south by Sarasota
County, and on the west by Tampa Bay and the Gulf of Mexico.
CLIMATE
Manatee County has a subtropical climate and a mean temperature
of about 72F. According to the records of the U. S. Weather Bureau,
the mean monthly temperatures at Bradenton range from 61.50F in
January to 81.2F in August, as shown graphically in figure 3. For com-
parative purposes, the figure includes also the average maximum and
minimum monthly temperatures during 1954.

























EXPLANATION
0I
Well penetrating aquifer above the Floridan
showing number assigned to well.
.2
Well penetrating the Floridan aquifer.
showing number assigned to well.


270 12'U-
82015'


82*10'
SARA SOTA


COUNTY


0 I 2 3 4 Miles

Figure 2. Map of eastern Manatee County showing locations of wells.


27023'



2720'


V







o

o
27J15'
LaJ
0



2720'



z
0

0






27 15'


82005'








8













4

-E

0.



























'S

'.5


Figure 3. Precipitation and temperature at Bradenton.


FLORIDA GEOLOGICAL SURVEY
















7 Aver ge moamum 5954
?-90
7T7- NVCA A A T O N


W 60 -- ( v go minimum m 195 d --


17' 40

SSEPT OCT NOV DEC JAN FEB MAR APR MAY JtIM JULY AUG SEPT OCT NOV DEC






REPORT OF INVESTIGATIONS No. 18


The average annual rainfall at Bradenton from 1880 through 1955
was 54.6 inches (fig. 3) but it ranged from as much as 75.78 inches in
1900 to as little as 29.45 inches in 1944. The average monthly rainfall
during the period of record ranged from 1.84 inches in November to 9.5
inches in July. About 60 percent of the yearly precipitation occurs
between June 1 and September 30.
PHYSIOGRAPHY
Manatee County lies within the Terraced Coastal Lowlands as de-
serilbed by Vernon (1951, p. 16), a subdivision of the Coastal Plain Prov-
ince. The topography is largely controlled by a series of marine terraces
formed during Pleistocene time, when the sea several times stood above
or below its present level.
The history of the Pleistocene epoch and the marine terrace deposits
in Florida that are associated with the fluctuations of sea level are dis-
cussed in detail in reports by Cooke (1945, p. 11-13, 245-312), Vernon
(1951, p. 15-42, 208-215), and Parker (1955, p. 89-124). The rise and fall
of sea level are attributed to the advance and retreat of the great conti-
nental ice sheets; the sea level declined as the glaciers expanded and rose
as they melted. When the sea was relatively stationary for long periods,
shoreline features and marine plains were developed. The remnants of
five marine terraces and four shorelines in Manatee County have been
previously mapped (Cooke 1945, figs. 43-47; Parker 1955, pl. 10) as listed
in the following table:
TABLE 1. Pleistocene Terraces and Shorelines in Manatee County
Terrace Altitude of shoreline
(feet above msl)
Sunderland -----.............--......-- ---------------------------.1701
Wicomico ...............................................-------------.......................--------------------------100
Penholoway .---------------....................................................................................----------------------- 70
Talbot ..-.............------..--.....---..............------------- -- 42
Pamlico ........................................................................................................-- 25
,The highest land surface in Manatee County, about 140 feet above sea level,
represents a shallow sea bottom of Sunderland time.
Figure 4 shows the general configuration of the Pleistocene terraces
in the county as determined from aerial photographs, topographic maps,
and field observation. The highest and oldest surface represents an off-
shore portion of the Sunderland terrace (Cooke 1945, p. 278-279), which
was formed when the sea was about 170 feet above the present level
and covered practically all of southern Florida, including Manatee
County. During Wicomico time, when the sea was at an altitude of
about 100 feet, the only land area was in the northeastern part of the
county. It consisted of the Sunderland terrace and associated islands.











































W6 mcomrrc









SARASOTAtA COURTY
30 ~ CAI


Figure 4. Map of Manatee County showing Pleistocene terraces.


azoc-


--.00,


.3
-TI


82"40






REPORT OF INVESTIGATIONS No. 18


The shoreline of the Wicomico sea is marked by an escarpment that is
well preserved in many places. The base of the scarp is generally at an
altitude of about 90 to 100 feet.
The Penholoway terrace was formed when the sea was about 70 feet
above the present level and covered about two-thirds of the present
land area of the county. The shoreline of the Penholoway sea is marked
by a scarp that is well preserved in many places. The altitude of the
scarp base is generally about 60 to 70 feet.
The Talbot terrace was formed when the sea was 42 feet above the
present sea level and covered most of the western part of the county.
The shoreline of the Talbot sea is poorly preserved in most places and
is generally difficult to trace in the field. In the southeastern part of the
county, however, the shoreline is fairly well defined by a low escarp-
ment whose base is at an altitude of about 40 feet.
The Pamlico terrace is the youngest Pleistocene terrace that has been
recognized in the county. It was formed when the sea was about 25 feet
above the present level. A well-preserved scarp, whose base is at an
altitude of 20 to 25 feet, and other shoreline features generally mark
the shoreline of the Pamlico sea.
The Pamlico terrace forms a relatively flat coastal lowland that is
generally less than 20 feet above sea level, although it contains a few
low hills and ridges that rise to altitudes of 80 feet or more. The older
terraces form an upland of rolling hills that extends inland from
the Pamlico shoreline and gradually rises toward the northeast to an
altitude of about 140 feet. The Talbot and Penholoway terraces have
been modified to some extent by stream dissection but consist predomi-
nantly of low rolling hills having broad, relatively flat summits at alti-
tudes of about 50 to 80 feet. The Wicomico and Sunderland surfaces
have been more completely dissected by streams and the relief is more
pronounced; however, in many places they are still relatively flat and
drainage is poorly developed.
The surface drainage of the county is principally through the Mana-
tee, Little Manatee, and Myakka rivers and their tributaries. Much of
the coastal area is drained by small streams that empty directly into the
Gulf of Mexico. A large part of the county, however, is poorly drained
and contains many ponds anid swamps. A network of canals has been
dug throughout most of the county to supplement the natural drainage.
HISTORY
Manatee County was established in 1855 and originally included
the area that is now Hardee, De Soto, and Sarasota counties. De Soto






12 FLORIDA GEOLOGICAL SURVEY

County was separated from Manatee County in 1887, and Sarasota
County was created from the southern part of Manatee County in 1921.
The county received its name from the manatee, or sea cow, which
inhabited the surrounding waters. The Spanish explorer, Hernando De
Soto, landed on Terra Ceia Island in 1539. His army landed on the south
side of the Manatee River at Shaws Point, which is now a national
monument.

POPULATION
The population of the county in 1950 was 34,547, an increase
of 32 percent from that of 1940 (fig. 5). About 90 percent of the total
population is in the western one-third of the county. Bradenton, the
county seat and largest city, had a population of about 13,000 in 1950.
The growth of population in Bradenton and Palmetto from 1895 through
1950 is shown graphically in figure 5.

INDUSTRY
The principal sources of income are agriculture and associated indus-
tries, commercial fishing, and the tourist trade. The mild climate and
the ready supply of water for irrigation have been the predominant
factors in making the county one of the State's most productive agri-
cultural areas. The agricultural use of land in the county in 1954, accord-
ing to the U. S. Bureau of the Census, is given in table 2. In 1948 more
than 3.5 million pounds of food fish were caught and marketed, in addi-
tion to shellfish, crabs, shrimp, and miscellaneous seafoods. The mild
climate, beaches, waterways, and game fish annually attract thousands
of tourists from all parts of the country. Mineral products from the
county include limestone, dolomite, sand, and shells.

TABLE 2. Agricultural Use of Land in Manatee County in 1954
Acres
Approximate land area ......---......--..--....---.......................-------------------------................................... 448,640
Farmland .....-------------....---..........-.....-...........--------..-....-.............-.................-...............-... 809,125
Cropland harvested ---------..-........-..-.....-.......-----.........--..----...-..-..-............. 15,614
Vegetables .---------...........-.....-----...--..-----...-....-...-........ 4,558
G roves ... ...................................................... 8,407
Flowers and shrubs .-..--....-------...-......---..........-..-.......... 2,082
O their ......... .. ............................................ 567
Cropland not used .................................................................. 7,830
Total land pastured ..................................---------------------------........................ 266,803
Cropland pastured .-.................-----....----...........-............- 17,619
Pastureland ......................................................... 109,567
Woodland pastured ......-..-------...-...---.....-.....-.................. 189,617
W oodland not pastured ............................................................. 10,602
Other land not pastured ............................................................ 8,776








REPORT OF INVESTIGATIONS No. 18 18


14



CITY OF 3RADE NTON .
10



















CITY OF PALMErTO
il0l




- -o- I I I I I I I ... .. ..r-7. .
LiI) ___" ll_. Il
2I / .
(1)6- 11.. .
0 .
..I-. . .
zI~ . .


iia i l.. .. ..""- '


Figure 5. Population growth in Manatee County and the cities of Bradenton and
Palmetto, 1890-1950.






FLORIDA GEOLOGICAL SURVEY


TRANSPORTATION
U. S. Highways 19, 41, and 301, in addition, to many State highways,
provide easy access to all parts of the county and to adjacent counties.
The Atlantic Coast Line Railroad and the Seaboard Air Line Railroad
provide rail transportation, and scheduled air flights and bus service
also are available.

GEOLOGY
Thec known geologic formations of Manatee County range in age from
Recent to Cretaceous. They are listed and briefly described in table 3.
The surface formations consist predominantly of undifferentiated depos-
its of Pleistocene and, probably, Pliocene age; however, beds of Miocene
age are exposed at some places. The subsurface formations are described
on the basis of studies of rock cuttings, electric logs, and drillers logs of
wells in Manatee and adjacent counties. Detailed logs of selected wells
are included in table 7.
PRE-TERTIARY ROCKS
Rocks older than middle Eocene in Manatee and adjacent counties
are known only from a few deep oil-test wells. The data from these wells
indicate that rocks of Cretaceous age occur at a depth of about 5,000
feet in Manatee County. Well 26-22-1, drilled in 1955 by the Magnolia
Petroleum Corporation, entered the Upper Cretaceous at 5,120 feet
below sea level and ended in Cretaceous rocks at more than 10,000 feet
below sea level. The Cretaceous rocks consist of interbedded shale,
limestone, and anhydrite and contain highly mineralized water. Water
from near the bottom of well 26-22-1 contained more than 100,000 ppm
of chloride, whereas sea water generally contains less than 20,000 ppm of
chloride.
TERTIARY SYSTEM
The formations of Tertiary age in Manatee County and their approxi-
mate thicknesses are listed in table 3, but only those formations that are
penetrated by water wells (fig. 6) are discussed in this report.
EOCENE SERIES
Avon Park Limestone: The upper part of the late middle Eocene
in Florida was named the Avon Park limestone by the Applins (1944, p.
1680, 1686). It crops out in Citrus and Levy counties and is the oldest
formation exposed at the surface in Florida. It is also the oldest forma-
tion penetrated by water wells in Manatee County.
Lithologically, the Avon Park, in the county, ranges from white or
tan, fairly soft, coquinoid or granular limestone, to dark brown, hard,
crystalline dolomite. Most of the formation is dolomitized to some








REPORT OF INVESTIGATIONS No. 18


Table 8. Geologic Formations of Manatee County


Pamlico sand1
Older terrace
deposits


Caloosahathooee
imarl?
Boneo Valley
formation
Hawthorn
formation




Ta'mpa
formation


uiwastono
lliestoneo


Ocala group




Avon Park
limestono



Lako City
limestone
Oldsmar
limostoneo


Codar Keys
formation


Soil, muok, alluvium, sand.


Rand, shells, limestone,
Sand,


Marl, sand and gravol of quartz and( phosphate, shells,
1)ono fragments.
Sand and gravel of quartz and phosphate; clay, bone
fragments.
Clay and marl, gray, greonish and bluish gray, sandy,
phosphatio, oalcaroous, interboddod with sandy
lmostono, si, sand, and shells. The sand, sholl, and
li nostono bode are the souroo of small water supplies.
The water in the Hawthorn formation is undor ar-
tosian pressure and is gonorally loss minutralizod than
the water in the Tampa and oldor formations.
Limestone, white, gray and tan, gonorally hard, d(ono,
sandy, phosphatio in part, silioifiod in part, fossil-
iforous. Porosity due primarily to solution cavities.
Yields largo quantities of artesian water.
Limestone, oroamy white and tan soft to hard, granu-
lar, porous, crystalline, and dolomitic in part, very
fossiliforous. Gonorally a more productive source of
artesian water than tho T'ampa, but water is some-
what more mineralized in theo eastern part of the
county.


Limestone, white, croam, tan, chalky, s)'ft, granular,
porous, coquinoid in pait, with some hard, denso
layers and some thick beds of brown, crystalline
dolomite. Probably a productive source of artesian
water but penetrated by only a few wells. Water is
relatively high in mineral content in the coastal area.
Li'nostono, cream, tan, and brown, soft to hard, granu-
lar and coquinoid in part, crystalline and dolomitio
in part, very porous. Probably a very productive
source of water, but tapped by very few wolls. Water
is probably high in mineral content in theo coastal
area.
Limestone, cream and tan, chalky to granular, dolo-
mitio and gypsiferous in part, and very fossiliferous
in part.
Limestone, tan and brown, granular, porous; inter-
bedded with chort, anhydrite, and tan to brown,
crystalline, porous, dolomite.


Limestone, cream to tan, fairly hard, granular, gyp-
siforous, interbodded with tan to brown, crystalline
dolomite, fossiliferous in part.


Limestone, shale, anhydrite


8ysi om


Sorios


Formnation


300-325




700




500

950


2,000


-- --------- I ----- --c--.-------- -.I ----- --------- --------- -----~~---- ------,,,,I,,-,,~.


--------I-----------I-------~---~---- -------- 1------------11~


-------II c~~I-I- --I-~-~-~---I-.


- ----- -----------------------


Thicknoss
(foot)

0-20


0-20
0-(10


0-10
0-30?

150-300




125-235



150-300


Al






FLORIDA GEOLOGICAL SURVEY


41


PY I;INI titii I l


II ~OHMA I (AION NO(
,AAT(( (N IO(MAT~tN (MIOCE NH
fUIIMAI ION (tC i

IiA A (61001) (f Lid NCI- *' Ir-


Figure 6. Cross sections showing the geologic formations penetrated by water wells
in Manatee County.

degree and much of it is very fossiliferous, containing bryozoans, coral,
(ehinoids, mollusks, and many foraminifers, including specimens of
Dictyoconus cooked, Lituonella floridana, Spirolina coryensis, and Valvu-
lina intermedia.
The Avon Park limestone is about 700 feet thick in Manatee County
and is generally very permeable, owing to the extensive development of
solution channels. Several wells obtain water from the Avon Park and
it is probably a productive source of artesian water throughout the
county. In the coastal area, however, the water probably is highly
mineralized.
Ocala Group: Until recent years, all the limestones of late Eocene
(Jackson) age in peninsular Florida were considered a single formation,
the Ocala limestone. As shown in table 4, Cooke (1945, p. 53-62) and
the Applins (1944, p. 1683) referred all the late Eocene limestone to the
Ocala limestone; however, the Applins recognized an upper and a lower






REPORT OF INVESTIGATIONS No. 18


member on the basis of lithologic and faunal differences. After comple-
tion of his studies in Citrus and Levy counties, Vernon (1951, p. 111-171)
separated the late Eocene limestones into two formations: the Ocala
limestone, restricted to the upper part, and the Moodys Branch forma-
tion. Vernon also divided the Moodys Branch formation into two mem-
bers: the Williston member (upper) and the Inglis member (lower).
Table 4. Stratigraphic Nomenclature of the Upper Eocene in Florida

U.S. Geological Survey Floridat Geological Survey
Cooke (1945) Applins (1944) Vernon (1951) Puri (1953)
Upper OcIal liiiestono Crysitl
iieiumboer (restricted) River
formation
Oeala Ocala Ocala
lineA1tone limestone groups
Lower Moodys Williston Williston
member Branch member formation
formation
Inglika Ingli
moimbor formation

Puri (1953, p. 130) changed the Ocala limestone (as restricted by
Vernon) to the Crystal River formation and gave formational rank to the
Williston and Inglis 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.
The Ocala group lies unconformably on the Avon Park limestone in
Manatee County and is about 800 to 325 feet thick. The upper part con-
sists predominantly of cream, tan and grayish-tan, soft, chalky, highly
fossiliferous limestone. The lower part is similar but contains beds of
brown and tan, hard, crystalline dolomite and dolomitic limestone. The
Ocala group is penetrated by only a few wells in the county, although
it may be a productive source of artesian water. In the coastal areas,
however, the water in the Ocala group has a relatively high mineral
content.

OLIGOCENE SERIES
Suwannee Limestone: As used in this report, the Suwannee limestone
includes all deposits of Oligocene age in Manatee County. The Suwannee
is differentiated from the underlying Eocene formations and overlying
Miocene formations on the basis of lithology and fossils, and is separated
from these formations by unconformities.
The upper part of. the Suwannee is generally a creamy-white to tan
soft to hard granular porous limestone, with some beds of crystalline and






FLORIDA GEOLOGICAL SURVEY


dolomitic limestone. It contains many echinoids, mollusks, and foramini-
fers. The lower part is generally tan to gray, and it is harder, more crys-
talline, more dolomitic, and less fossiliferous than the upper part. Dictyo-
conus cooked and Coskinolina floridana are found in the Suwannee in
the western part of the county. They are generally restricted to the lower
part of the Suwannee and may be diagnostic of the lower Suwannee in
that area. However, these foraminifers were not found in the Suwannee
in the eastern part of the county. Specimens of Rotalia mexicana are
fairly abundant in the Suwannee limestone throughout the county.
The contours on the map in figure 7 represent the approximate alti-
tude and the configuration of the top of the Suwannee limestone in
Manatee County. The contours were drawn on the basis of well cuttings,
drillers logs, and electric logs. The dashed lines in the eastern part of
the county, where no control wells were available, were drawn on the
basis of information from wells in adjacent counties. As shown on this
map, the top of the formation ranges in depth from about 325 feet below
sea level in the northeastern part of the county to more than 550 feet below
sea level in the southern and southeastern parts of the county. The thick-
ness of the formation ranges from about 150 feet in the northeastern part
of the county to about 300 feet in the southwestern part.
The Suwannee is the most productive source of artesian water gen-
erally tapped by wells in the county. In the coastal area, the water in
the Suwannee is somewhat more mineralized than the water in the over-
lying Tampa formation.

MIOCENE SERIES
In this report, the deposits of Miocene age in Manatee County are
referred to the Tampa formation of early Miocene age (Cooke 1945, p.
107) and the Hawthorn formation of middle Miocene age. Both the
Tampa and Hawthorn formations are of marine origin, but they repre-
sentit different depositional environments and are probably separated by
an Inicoilformity.
Tampa Formation: The Tampa formation lies unconformably on the
Suwannee limestone of Oligocene age and consists of white, gray and
tan, hard, dense, sandy limestone which contains fine-grained phosphorite
inii some places. The limestone is crystalline and dolomitic, in part, and
contains thin beds of chert. It is generally fossiliferous, containing echi-
noid plates and spines, ostracods, foraminifers, and many molds and
casts of mollusks. Specimens of the foraminifers Archaias floridanus and
Sorites sp. are fairly abundant throughout the formation.
The contours on the map in figure 8 represent the approximate alti-
tude and configuration of the formation. They were drawn on the basis






ev4 40.
27*39.----


I


351 S'


1 1Li


I TK 9 4


I


II AcPOiS14


~fl77Irf


I \ I


27'


0
0



z






0
z

z

00>


, ; I _i I -. __M ;hoc_ i N i





he r II


74i


I I 1 rl i ~--I- I II


%. .
lk,


-a


Srftr


.....*


1 \


7


--I -"r ^ 770 P :S *- T- ,














EXPLANATION 475-

Well (drillers log available) -
525-r
Well (cuttings available) \ _

Well (electric log available 0 4m N \ T '* \

Well (cuttings and electric log available) .\

500- -- 500 .- \
Depth, ,n feet below mecn see level

Q \%
E P I % -, 0
Figure 7. Structure-contour map of the top of the Suwannee limestone in Manatee
County.























2 10'71

















Wenl (cuttings avokacee) \
o *
Well electricc log c,,ilblde) cr. ,^ r-s~-* 25 I? ..

Well (cuttings and eleCereC log ovCocble) -

200200 L
Depth, in feet below mean sea level

Dp. t,-.-- below......... -.
-'* ,c ~c"' *2'CS'


Figure 8. Structure-contour map of the top of the Tampa formation in Manatee
County.






REPORT OF INVESTIGATIONS No. 18


of information from electric logs, drillers logs, and the study of well
cuttings. The dashed lines in the eastern part of the county, where control
wells were not available, were drawn on the basis of information from
wells in adjacent counties. As shown on the map (fig. 8) the top' of
the Tampa ranges in depth from about 200 feet below sea level in the
northern and northeastern parts of the county to more than 350 feet
below sea level in the southwestern part. The thickness of the formation
ranges from about 125 feet in the northeastern part of the county to about
235 feet in the southeastern part. The average thickness is about 150 to
175 feet.
The Tampa formation generally has a relatively high permeability
owing to numerous interconnecting solution cavities. It is a very produc-
tive source of artesian water in most parts of the county.
Hawthorn Formation: The Hawthorn formation, as used in this
report, includes all deposits of Miocene age that are younger than the
Tampa formation. The Hawthorn consists of gray, bluish-gray and
greenish-gray, sandy, calcareous clay interbedded with white, gray, and
tan sandy limestone and thin beds of sand and shells. The clay and lime-
stone layers contain different amounts of chert, dolomite, sand, and phos-
phorite grains and pebbles. The limestone layers are fossiliferous, in part.
The top of the Hawthorn is an irregular erosion surface that generally
ranges from about 10 feet above sea level to about 50 feet below sea level
in Manatee County. The Hawthorn is exposed along some streams and
in shallow ditches in several places in the western part of the county.
The thickness of the formation ranges from about 150 feet in the north-
eastern part of the county to more than 350 feet in the southern part,
increasing in the direction of dip of the formation.
The beds of sand and limestone yield artesian water to many domestic
and some irrigation wells. The water is generally less mineralized than
that in the Floridan aquifer. Because of the low permeability and the
thickness of the clay layers, the formation serves as a confining layer for
the water in the underlying limestone formations of the Floridan aquifer.

PLIOCENE SERIES
Deposits of Pliocene age in Manatee County were referred by Cooke
(1945, p. 208-223), to the Bone Valley formation and the Caloosahatchee
marl. The Bone Valley formation consists of sand, gravel, clay, and phos-
phorite pebbles and is supposed to be present in much of the eastern part
of the county. In well 17-11-1, sediments from the interval between five
feet above sea level and about 40 feet below sea level consist of sand and
gravel of quartz and phosphorite, with some clay and impure limestone
,near the base. These sediments, which are underlain by the Hawthorn






FLORIDA GEOLOGICAL SURVEY


formation, probably represent the Bone Valley formation. Material of
similar lithology, in a ditch north of Ellenton, was referred to the Bone
Valley formation by Cooke (1945, p. 208).
The marl, shell, and limestone beds overlying the Hawthorn forma-
tion in the western part of the county were included in the Caloosahatchee
marl by Cooke (1945, p. 223). In some places the Hawthorn formation
is overlain by a thin bed of sandy weathered material containing pebbles
of quartz, phosphorite and bone fragments. In other places it is overlain
by a thin bed of marl containing sand and gravel of quartz and phos-
phorite, marine shells, and bone fragments. These beds, which appear
to be discontinuous and are generally less than 10 feet thick, may be of
Pliocene age. The shell and limestone beds at or near the surface through-
out much of the coastal area have been previously referred to the Caloosa-
hatchee marl, but they appear to the author to be of Pleistocene age.
PLEISTOCENE SERIES
Pleistocene sediments older than the Pamlico sand consist predom-
inantly of nonfossiliferous sand which ranges in thickness from a few
feet to about 65 feet. In some places the sediments contain a layer of
hardpan a few feet beneath the surface, which confines the water beneath
it under slight artesian pressure. They are a source of water for small
irrigation and domestic supplies in the eastern part of the county.
The Pamlico terrace is underlain by sand, sandy limestone, and shells.
The beds of limestone and shells generally occur at altitudes less than 20
feet above sea level and pinch out seaward from the Pamlico shoreline.
They were probably deposited during late Pleistocene time. The bed of
shell contains a fauna very similar to that of present beach deposits;
however, Cooke (1945, p. 222-223) reports that extinct species have been
found in a bed of shells of apparently the same age in Hillsborough
(County. The Pleistocene sediments beneath the surface of the Pamlico
terrace range in thickness from less than 1 foot to about 50 feet and are
tapped by a few domestic wells.
GROUND WATER
PRINCIPLES OF OCCURRENCE
Practically all the usable water of the earth moves through the vast
circulatory system known as the hydrologic cycle. In this cycle, water
condenses from the moisture in the atmosphere and falls as rain or snow.
Then it moves over and beneath the land surface to the oceans and is
returned to the atmosphere. Actually, the cycle may be modified or
completed at any time after the water condenses from the atmosphere,
as evaporation may begin even before the water reaches the earth, and


22






REPORT OF INVESTIGATIONS No. 18


continues throughout the entire cycle whenever air undersaturated with
moisture has access to the water. Also, great quantities of water are
returned to the atmosphere by the transpiration of plants.
Subsurface water may be divided into two general classes-suspended
(vadose) water and ground water. Suspended water is the water in the
zone of aeration-the zone in which the interstices of the soil or rocks,
whether, full or not, contain water, under less than atmospheric pressure.
Ground water is the water in the zone in which all the interstices are
filled with water under pressure greater than atmospheric. This saturated
zone is the reservoir that yields water to all springs and wells.
The water in the zone of saturation may occur as (1) unconfined
ground water (under nonartesian conditions) or as (2) confined ground
water (under artesian conditions). Where the ground water is not con-
fined, and its upper surface is under atmospheric pressure and is free
to rise and fall, it is said to be under nonartesian conditions. Its upper
surface is called the water table. Where the water is confined in a per-
meable bed that is overlain by a relatively impermeable bed, its upper
surface is not free to rise and fall and it is said to be under artesian
conditions. The term "artesian" is applied to ground water that is con-
fined under sufficient pressure to rise above the top of the permeable bed
that contains it, but not necessarily above the land surface.
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. Recharge is the process of replenishment of the
aquifer with water, and areas in which it occurs are known as recharge
areas. Generally, nonartesian aquifers may receive recharge throughout
their extent, whereas artesian aquifers receive recharge only where their
confining beds are absent or somewhat permeable.
The piezometric surface of an aquifer is an imaginary surface to which
water from an artesian aquifer will rise in tightly cased wells that
penetrate the aquifer. Where the piezometric surface is above the land
surface, artesian wells will flow under natural pressure.
GROUND WATER IN FLORIDA
Ground water occurs in Florida under both nonartesian and artesian
conditions. Nonartesian conditions occur generally in the shallow deposits
of sand, gravel, shells, and limestone which constitute many aquifers of
relatively small areal extent. These deposits are the source of many
domestic water supplies throughout the State and also of public and
industrial supplies in areas where the deeper formations contain salty
water. The water in the nonartesian aquifers is supplied chiefly by
,infiltration of local rainfall.


"23






FLORIDA GEOLOGICAL SURVEY


ARTESIAN WATER
Most of Florida is underlain by a thick section of permeable limestone
formations of Eocene, Oligocene, and Miocene ages. These formations
make up an extensive artesian aquifer from which most of the large
ground-water supplies of the State are obtained. Stringfield (19386, p. 125-
13'2, 146) described the aquifer and mapped the piezometric surface in
1933 and 1934. The name "Floridan aquifer" was introduced by Parker
(1955, p. 188-189) to include "parts or all of the middle Eocene (Avon
Park and Lake City limestones), upper Eocene (Ocala limestone), Oligo-
cene (Suwannee limestone), and Miocene (Tampa limestone, and per-
meable parts of the Hawthorn formation that are in hydrologic contact
with the rest of the aquifer)." The artesian water is confined by relatively
impermeable layers in the limestone formations and by the overlying clay
beds of Miocene age which are present in most of the State, The water
in the artesian aquifer is replenished chiefly by rainfall in areas where the
confining beds are absent or sufficiently permeable to permit the passage
of substantial quantities of water from the surface into the limestone.
Piezometric Surface: The configuration of the piezometric surface in
peninsular Florida is shown by contour lines in figure 9. These contour
lines represent the height, in feet above sea level, to which water will
rise in wells that penetrate the Floridan aquifer The lines indicate the
areas in which recharge occurs and the direction of movement of the
water inl the Floridan aquifer. In areas of recharge, the piezometric surface
is relatively high. The water moves away from these areas in the direc-
tion of steepest gradient, at right angles to the contour lines, toward
areas of discharge, where the piezometric surface is relatively low. The
piezometric surface in central Florida forms an elongated dome which is
centered in northern Polk County. This dome indicates that the lake
region of Polk County is the center of a relatively large area of recharge
which probably extends into adjacent counties (Stringfield, 1936, p. 148).
The water enters the limestone formations in this area through the num-
erous sinkholes that penetrate the confining bed, or at places where the
confining bed is absent.
The small ridge on the piezometric surface in Pasco County indicates
that recharge occurs also in parts of Pasco, Hernando, and Hillsborough
counties. The basin-shaped depression in the piezometric surface in the
vicinity of Tampa Bay is the result of discharge of water from the artesian
aquifer through springs and wells.
GROUND WATER IN MANATEE COUNTY
Ground water in usable quantities occurs in all formations penetrated
by wells in Manatee County. The beds of shell and sand of Pliocene and







REPORT OF INVESTIGATIONS No. 18 25

.. .. 682' 0I' 0.*


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Lion y WA LLA A lld1 A


0 \h-:-_- l, 1 0 vi \ C0


---1 (
SI < -, oRANKLI 90 0 .
Ln LoVaY sv MARION "L-









e t p a na on o i
01 I e 1 0\0
4 /1 !O LS N I A R









I HIGHLANDS 'yj+




L E HENRY PALM OEACH


Or\, ,_o \ /0"'._ ....._..L
1 Rnins i n t i l Ot WARD
0 \J L 80 0 1' -OSCEOLAN 9 21






EXPLA ANATIEN P L




Contour lns represent approximately the height, AE
In feet above mean sea level, to which water \
would have risen in tightly cased wells that
penetrated the principal artesian aquifer in
1949. --.


Approximate 8so0le W '.Jo

Figure 9I Map of the Florida Peninsula showing the piezoetric surface.
Figur 9. Mp ofthe ForidaPenisula howin thepieorntfosurlfae






FLORIDA GEOLOGICAL SURVEY


Pleistocene age yield water to many domestic wells. The water in these
deposits is replenished by local rainfall. In some places it is confined
under slight artesian head by layers of hardpan, clay, or limestone.
Reports by drillers indicate that most of the shallow wells in the county
penetrate at least one thin bed of clay or limestone that confines the
underlying water under artesian pressure, although the pressure is not
generally sufficient to produce a flowing well.
ARTESIAN WATER
In Manatee County, as in most of the state, the Floridan aquifer is the
priticipal artesian aquifer. Probably most of the water in the Floridan
aquifer in Manatee County comes from rainfall that infiltrates into the
aquifer in the recharge area of Polk County. From there it moves south-
westward into Manatee County, as indicated by the configuration of the
contours in figure 9. However, some recharge may occur in the north-
easternt part of Manatee County, where the piezometric surface is con-
siderably lower than the water table and ground water from the non-
artesian aquifer may percolate through the confining beds into the
Floridatn aquifer.
The Avon Park limestone and the Ocala group are penetrated by a
few wells in the county and are probably capable of yielding large
quantities of water, but they have not been used extensively because the
Suwannee limestone and Tampa formation yield enough water to supply
most wells. The water in the Suwannee limestone and the Tampa forma-
tion occurs in permeable zones that are generally separated by layers
of low permeability which retard the vertical movement of water. These
layers are discontinuous and are not completely impermeable, however;
hence, water may move from one to another permeable zone.
The Hawthorn formation, consisting predominantly of clay and marl,
serves ais a confining bed for the water in the underlying limestone forma-
tions. Thin beds of sand, shells, and limestone within the formation, which
are generally separated by relatively thick beds of clay, are the source of
many domestic and small irrigation supplies. These permeable beds
within the Hawthorn are generally separated from the Floridan aquifer
by layers of clay or marl.
The piezometric surface of the Hawthorn formation has not been
mapped; thus, the area of recharge is not known. Some recharge, at least
to the upper part, probably occurs in eastern Manatee County. The
lower part of the Hawthorn probably receives considerable recharge
from upward leakage of water from the Floridan aquifer, as the artesian
pressure in the Hawthorn is considerably less than that in the Floridan
aquifer.







REPORT OF INVESTIGATIONS No. 18


27


Current-meter Exploration: In order to determine the depth, thick-
ness, and relative productivity of the permeable zones in the limestone
formations, explorations were made in several selected wells with a deep-
well current meter, a device for measuring the velocity of the flow of
water through a well bore. The results of the current-meter traverses,
and other data pertaining to these wells, are shown graphically in fig-
ures 10-16. The velocities are expressed in revolutions per minute (rpm)
of the current meter. Actual flow rates, which are a function of velocity
and cross-sectional area, cannot be computed accurately, as the diameter
of the uncased part of the well bore is not uniform.
The results of a current-meter traverse in well 27-28-2 are shown
graphically in figure 10, which includes also an electric log of the forma-
tions and a diagram showing the construction of the well. The well was
Z SELF-POTENIIAL HELAlIVE RESISTIVITY VELOCITY
AGE 9 I0 my 25 ohms (rpm of current meter)
toL .... 50 0 0n Im


100




200




300




400




500


600


Figure 10. Graphs showing data from well 27-28-2, seven miles southeast of
Bradenton,







28 FLORIDA GEOLOGICAL SURVEY

flowing at the rate of about 450 gpm while the traverse was being made.
The velocities show that little or no water entered the well below a depth
of 615 feet. Some water entered the well between depths of 615 and 570
feet, but most of the total yield of the well was obtained from the interval
between 560 and 540 feet. The permeable zones of the Tampa formation
above 450 feet yielded some water. The large variations in velocity in
the uncased part of the well probably represent differences in size of
the well bore. The higher velocities in the cased part of the well indicate
that the diameter of the uncased part is considerably larger than eight
inches.
The velocities in well 28-29-3 (fig. 11) were determined when the
well was flowing at the rate of about 60 gpm. They indicate that the
Suwannee limestone yielded no water below a depth of 605 feet and that
most of the water from this formation was obtained from the intervals

E LF PO LNIIHAL RLLAtIVE hESIslivIl Y VELOCIIY
^G 10 my 25 Ohms (rpm of current meler)
-- 0 50 100
Pliocene .
0 and




o100 o----- t 00



I o.
.t

_200 _200


0
L a.J, o-







400. __400



500 I -- 500


OU W

S400 -- I. -- --- 600


Figure 11. Graphs showing data from well 28-29-8, six miles southeast of Bradonton.






SELF- POTENTIAL RELATIVE RESISTIVITY VELOCITY CHLORIDE CONTENT TEMPERATURE
AGE 10 my 25otms (rpm of current meter) (parts per million) (degrees Faireeit)
0_-" -o 50 100 500 100 1.500 2000 2,500 0 81 82




oo 0



100 W----- -- ------------ ^ ---------- ---- X




us a



O a ________ jar' _____ / o 8
3f 0





a 00

















soc = ----= ----- soo
Figure 12. Graphs showing data from well 28-41-4, near Cortez.











IN FEET


BELOW MEAN SEA LEVEL


-I

C'
C'













0
to
0





0
0
Ca
0



0
0


DEPTH,


o oj ro o
6 o o o a
0 0 0 0 0
0 0 0 0


0
.5'

3


b.,








CA


rri
I-
0
C)
-4


I IcpO
C,
C
.5'
-q


03



U,






REPORT OF INVESTIGATIONS No, 18 31

between depths of 605 and 585 feet and 525 and 505 feet. Most of
the total yield of the well was obtained from the Tampa formation,
between depths of 445 and 405 feet and 365 and 340 feet. The variations
in velocity between depths of 335 and 200 feet are due to differences
in size of the well bore, and they reflect the hard and soft layers in the
Tampa and Hawthorn formations. The higher velocities in the 6-inch
casing indicate that the diameter of the uncased part of the well is more
than six inches.
The velocities in well 28-41-4 were determined when the well was
flowing at the rate of about 60 gpm. They are shown in figure 12. Most
of the water from the Suwannee limestone entered between 590 and 520
feet. Some water was obtained from the Tampa formation between
depths of 480 and 470 feet, but most of the water from this formation
entered the well between 420 and 365 feet. The productive zones



SELF- POTENTIAL RELATIVE RESISTIVITY VELOCITY
Lt g 10 my 25ohms (rpm of current motor)

o oLI EN .........
PLIO NE .


100- 100



200, 200



300 02300

S0 400
ILt S ^^

0 --- --- 1T^'^ 4^rAo


Figure 14. Graphs showing data from well 80-28-1, seven miles cast of Bradenton.










SELF POTENTIAL
10 mv


RELATIVE RESISTIViTY
25ohms


VELOCITY


CHLORIDE CONTE14T
(Darts per mallac)


200






300





400 ><


Figure 15. Graphs showing data from well 38-32-5, five miles northeast of Terra
Ceia.


AGE 9






REPORT OF INVESTIGATIONS No. 18


indicated by the velocities correlate generally with changes in chloride
content and temperature, as shown in the figure.
Well 29-29-4 was flowing at an estimated rate of 110 gpm when the
velocity measurements shown in figure 18 were made. The velocities
indicate that most of the total yield was obtained from the Tampa for-
mation, in the interval between depths of 450 and 860 feet. The large
variations in velocity probably represent differences in the diameter of
the well bore. The decrease in velocity above a depth of 50 feet may
represent a loss of water to a permeable zone in the Hawthorn formation.
Well 80-28-1 was flowing an an estimated rate of 500 gpm when the
velocity measurements shown in figure 14 were made. The velocities indi-
cate that no water entered the well below a depth of 500 feet. Some
water entered the well between depths of 500 and 470 feet and a large
quantity entered between 465 and 430 feet. Most of the water came from
the Tampa formation in the interval between 375 and 350 feet, but some
may have entered the well from the upper part of the formation, between
240 and 230 feet. The large variations in velocity above a depth of 850
feet probably represent differences in the diameter of the well bore.
The velocities in well 88-32-5 were measured when the well was
flowing at the rate of about 400 gpm. They are shown in figure 15. The
velocities indicate that no water entered the well below a depth of 450
feet. A large part of the total yield was obtained from the upper part of
the Suwannee limestone between depths of 450 and 420 feet. Some water
probably entered the well from the Tampa formation between depths
of 880 and 860 feet, but most of the water from this formation entered
between 350 and 825 feet. The decrease in velocity above a depth of
225 feet represents a difference in the size of the well bore, as shown in
the diagram.
Artesian Head: Water-level measurements were made in many wells
during the investigation, to determine the altitude of the artesian pres-
sure head in different parts of the county and in the different formations.
These measurements, published separately as Florida Geological Survey
Information Circular No. 19, show that the water in the Tampa formation
and the water in the Suwannee limestone are under approximately the
same artesian pressure head; however, small differences may occur locally
during periods of heavy withdrawals. The head in the Hawthorn forma-
tion is generally several feet lower than the head in these underlying
formations of the Floridan aquifer.
Because the head in the Floridan aquifer is higher than that in the
Hawthorn formation, water from it moves up through partially cased
wells and flows out into the permeable beds of the Hawthorn formation.
This is illustrated by the graph in figure 16 which shows the results of


88







FLORIDA GEOLOGICAL SURVEY


a current-meter traverse in well 29-37-10. This well does not flow at
the surface, and at the time the traverse was made the water level stood
about eight feet below the top of the casing. Water entered the well from
the Tampa formation and the top of the Suwannee limestone in the inter-
val between depths of 450 and 325 feet, moved up the well and out into
the Hawthorn formation above the top of the 6-inch casing, in the
interval between depths of 70 to 60 feet.
Fluctuations of water level in artesian wells range from a fraction
of a foot to several feet and are caused by one or several factors. The
larger fluctuations are generally due to daily and seasonal variations in
withdrawals of water from wells or to recharge from rainfall. Minor
fluctuations are caused by such factors as ocean tides, atmospheric-
pressure changes, winds, earthquakes, and passing trains. These factors
and their effects on water levels are discussed in detail in a paper by
Parker and Stringfield (1950).
z SELF- POTENTIAL RELATIVE RESISTIVITY VELOCITY
AGE :o 10 mv 25ohms (rpm of current meter)
u. 0 20

0 Plestocend --
Phliocene
O-- O


100 100

0
j U

J z

J z H



o ----- 300









40
S400- -- -- ------ --- 400




500 .----500

0 1


600 -------*-- -- : 600
Figure 16. Graphs showing data from well 29-37-10, four miles west of Bradenton.






REPORT OF INVESTIGATIONS No. 18


Records from continuous recording gages installed on four wells and
water-level measurements made periodically in more than 30 wells pro-
vide information on the fluctuations and progressive trends of the
artesian pressure head in Manatee County. These records show that the
largest fluctuations were caused by the variations in daily and seasonal
withdrawals of water from wells; however, observable fluctuations were
caused by earthquakes, changes in barometric pressure, and ocean tides.
Figures 17 and 18 show hydrographs prepared from records of the con-
tinuous recording gages, and figures 1.9-23 show hydrographs of 17 of
the wells in which water levels were measured periodically. Water-level
measurements in other wells are listed in table 6.
Measurements of water level in well 26-18-1 were begun in 1941. A
continuous recording gage was installed in February 1945 and is still
in operation. The hydrograph of this well (fig. 17) shows seasonal fluc-
tuations and the general trend of artesian pressure head from June 1941
to December 1956. The seasonal use of artesian water in the area is
indicated by a decline in head during the periods of least rainfall when
large quantities of water were being used for irrigation. The higher head
during periods of greater rainfall may be due partly to recharge, but it
is due principally to a decrease in withdrawal. Seasonal fluctuations of
several feet occurred during the period from 1941 to 1948, but there was
apparently no progressive change in head. As shown by the hydrograph,
the magnitude of the seasonal fluctuations has increased and the head has
declined progressively since 1948, indicating a progressive increase in
both seasonal and perennial use of water. The water level in this well
reached a record low of 82.17 feet above sea level on April 28, 1956.
The hydrographs in figures 19-23 show the effects of seasonal use of
water from 1951 through 1955. Most of them show a slight progressive
decline in artesian pressure head during this period. The lowest water
levels were recorded in April and May 1956.
Earthquake waves passing through the earth's crust cause a rela-
tively rapid expansion and contraction of artesian aquifers and force
the water levels in wells to rise and fall. The effects of earthquakes on
the water level in well 26-18-1 are shown on the hydrographs in figure
24, which were traced from charts of the automatic 'recording gage.
The destructive earthquake that occurred in the Dominican Republic
on August 4, 1946, caused a maximum water-level fluctuation of 1.15
feet, and an after shock of this earthquake on August 8, 1946, caused
a maximum fluctuation of 0.17 foot. A severe earthquake in north-
western Costa Rica on October 5, 1950, caused a maximum fluctuation
of 1.55 feet.
The daily changes in atmospheric pressure cause minor fluctuations


35











-?. 1 ..


35 --..... "--, -.. .. --,. ... -- "--3 5
3---7----..----- ---,,--- -- -------_ 4
S -----------'- -- ---- -- -------------------^ -- ----- --- ....- .T-o- ---...."--------. _- ,
-)1- e 42



____ 9_3______9_________9___9_9_9__9 4' 9 9i 5 j, f V
SWLL 26--40








32 932
> I





8 o8







24 24
,-"20 ,_-20



;'


Figure 1. Hydrograph of wel 6-11 and raiall at Bridenton.
Figure 17. Hydcrograph of well 26-18-1 and rainfall at Bradenton.


0

0
0
0


C-,

Lu







REPORT OF INVESTIGATIONS No. 18


21




I


Figure 18. Hydrographs of wells 27-36-3, 28-31-1, and 31-34-6.


23~"- I" TT''~llll-l-IT- l" l b~1'"'-s'


21







WELL 27-36-3, 4 MILES SOUTHWEST OF BRADENTON











25



9-- ------- --- ----------i-- -- ------- ----|------------i---------------i--





SWell 28-31-1, 4 MILES SOUTHEAST OF BRADENTON






20 --



2 .---------- i -----I-----..----- --- ---.-



14
WELL 31-34-6, I MILE NORTHWEST OF PALMETTO

1 1952 1953 1954 1955 1956







FLORIDA GEOLOGICAL SURVEY


44 .....

43 -- -- -
WELL 17-I*I1, 4 MILES SOUTHWEST OF MYAKKA CITY
42


26 _ _


24 -
22 --..- -...---.--.



20 -------------
WELL 24-30-1, 4 MILES SOUTHEAST OF TALLAVAST
i n .. i. .1.. I I .-


30 .-.. .. I ....-- /.


WELL 28- 23-1, 12 MILES EAST OF BRADENTON
2 6 I . .. .. ..I. .

22
WELL 29-37-7, 4 MILES WEST OF BRADENTON
20 ... ____ ______________

14 -

I1 5 19521953 -1 5419--55

1951 1952 1953 1954 1955


17-11-1, 24-30-1, 26-41-2, 28-23-1, and 29-37-7.


Li_ L~L__I


/0'**'A


I


Figure? 19. HTydrogaphs of wells '








REPORT OF INVESTIGATIONS No. 18


w
LL


39


8000
CHLORIDE CONTENT OF WATER


4000
WELL 28-41-4, NEAR CORTEZ

WATER LEVEL

12-------


Figure 20. Graphs showing relation between water levels and chloride content of
water in wells 23-38-3, 28-41-4, and 29-40-10.








40 FLORIDA GEOLOGICAL SURVEY
i

-
WATER LEVEI










300-N

250-- --


200 -

150, ------ ------ ------^ -
_____ 1252 953


24
WATER LEVEL




10 .-- --- ---. -- ___


Figure 21. Graphs showing relation between water levels and chloride content of
water in wells 27-34-1, 27-38-7, and 27-41-1.








REPORT OF INVESTIGATIONS NO. 18


1,000

800


300
CHLORIDE CONTENT OF WATER
250 - j-^


_- I


i ., I I_


Figure 22. Graphs showing relation between water levels and chloride content of
water in wells 29-42-3, 831-37-12, and 33-35-4.


41


WELL 31-37-12, 2 MILES NORTH OF PALMA SOLA<


WATER LtVEL



-- --- -


200
24

22

20

18

16


--








FLORIDA GEOLOGICAL SURVEY


Figure 23. Graphs showing relation between water levels and chloride content of
water in wells 30-39-11, 31-43.3, and 31-44-3.


42


vi



4t


W
w
A
1x








042







REPORT OF INVESTIGATIONS No. 18


43.0


42.5



42.0


41.5


41.0


46.01


45.5


45.0-


4.. 5' 6 7 8 9 0o
OCTOBER 195046




F*-"Possage of hurricane center 40 miles NNW
Poyg vof well



Fluctuations caused by normal
atmospheric- pressure changes

OCTOBER 1946 j


Effects of earthquakes and changes in barometric pressure on the water
level in well 26-18-1, 12 miles northwest of Myakka City.


,-Maximum fluctuation: 1.15 feet

Maximum fluctuation: 0.17 foot.






,... DOMINICAN REPUBLIC EARTHQUAKES


3 4 5 6 7 8' 9
AU(UST 1946


R.


S 1 1 II
I NORTHWESTERN COSTA RICA EARTHQUAKE


---Maximum fluctuatitL : 1.52 feet


4'


Figure 24.


I-


r


- ----


a"TV.


4W


A e






FLORIDA GEOLOGICAL SURVEY


of water levels in most artesian wells. These fluctuations, however, are
often masked by larger fluctuations resulting from local pumping, ocean
tides, or other causes. The effects of atmospheric-pressure changes on
the water level in well 26-18-1, which is not affected by pumping or
ocean tides, are revealed by the hydrographs in figure 24. Periods of
high barometric pressure occur about noon and midnight and are shown
by low water levels at these times. The periods of low barometric,
pressure in the early morning and late afternoon are represented by
high water levels on the hydrographs. The magnitude of the fluctua-
tions in this well is generally less than 0.1 foot but may be considerably
greater when barometric pressure changes are greater than normal.
As shown in figure 24, the water level rose 0.45 foot on October 7, 1946,
when the center of a hurricane passed about 40 miles west of the well
at approximately 11:80 p.m. The lowest recorded barometric pressure
at Sarasota was 29.26 inches, and at Cortez it was 28.95 inches, or about
one inch lower than normal.
Piezometric Surface: The contours on the map in figure 25 show the
configuration of the piezometric surface of the Floridan aquifer in
Manatee County in September 1954. The piezometric surface was more
than 65 feet above sea level in the northeast corner of the county and
sloped westward to about 20 feet above sea level along the coast, in-
dicating a general westward movement of water. East of the 80-foot
contour, the piezometric surface has a fairly uniform gradient of about
1% feet per mile. The uniformity of the gradient indicates that no large
quantity of water was gained or lost by the aquifer in this area. West
of the 30-foot contour, the gradient is less than one foot per mile. The
configuration of the 20-foot and 22-foot contour lines indicates that
appreciable discharge is occurring near Palma Sola and Palmetto. As
the quantity of water being withdrawn from wells at the time the
water-level measurements were made was small, the low-pressure
trough around Palma Sola shown by the 20-foot and 22-foot contour
lines, is probably due in part to a movement of water from the Floridan
aquifer into the younger formations through unused irrigation wells.
Figure 26 shows the configuration of the piezometric surface in June
1955, during an extended period of dry weather when large quantities
of water were being withdrawn from irrigation wells. The altitude of
the piezometric surface ranged from about 60 feet in the northeast
corner of the county to less than 13 feet in the vicinity of Palma Sola.
A comparison of figures 25 and 26 shows that throughout the county
the piezometric surface was about five feet lower in June than in Sep-
tember; at some places in the western part of the county it was about
10 feet lower. The configuration of the contour lines in the coastal area







S- S C C Cuv
45 < SW82*3 252-V


j IN


I- -A ___ ___ __I: I ~~


;77-T7TT777~T--vTF1TT-rn-


Tifi/i


'V.


,i/ p *J-ff


i~~~/: /


7,-V .11111 LV1~'\ I~~Y


.1 .-i ri -c


dc 1 'I ; l


!I


ly~


')%is~~l: ~I~~~L~ P-~ r:~ (~. Li


INA IF gfigiefflumb. AL- I % I I ~ I %It % % AIL
i -7 -i -1-7roAR.Mbe
'gr
N-mt-.-s
---LA

MAC
*owe cc

IL


S~ ~ NAXJJJ~TSO.


I 'I\ I


25-


/I~" L- ~ IfiLRN


I VV-X-J I


e- 2%
S&34SC0a C C v *


k~Li~A~YA\ 'NiV\ \ Nr1~J


I> *~


nflowpnq well shower; well flurr.er
cnd ciliut~de of oiezormetryc slurftce

Flowing well showing well i,'.wiber cand
cltisude of prezer-e~ruc surface


WvC *wth recorder 7t1wwmg we-Cl number
an-d al:Itude a'of pezonetr#C Surface

fls,cvrg approxarnoie altitude cf bie
piezomoe'ric surface in feet cbove oieacn
see levei


__ IV \~XiiW


9 .- .o


Figure 25. Map of Manatee County showing the piezometric surface in September 1954.


z".


3


i ~-~Ljrr-C~s~pr?--;T--T~-iC~-l--~T-Ti-m


, L


-1.- !-.74 %.L 1 i I F -.4 4 i!7


-r- -P


% -- -1--e _


- [ -1i- 105 i P i i --t w t 0 1


I ld--, c e i 1 1 1 1 k -k = -X -4 4 4 ;-4


. 1~ ~ ~ ~ -1,i i 'f --t tb


U9 --- --- -


-M-


i 3F


i -c t t


vT-Ad~,L-


--


L~-Y- -~_ -- --~e-


1 :9 ; ._ _


, ---


I 14 -l


1( --- % t i -ll. N N-* I' tI*


l


. .-- 1 ,ICZ l


I


A\ A- i\ \










27 -7 -














I. l. 4 ''"---- -





EXPLANAT ONA
2 0' .P. 5 r';"

Nonflowing well showing well number Well with recorder show- g well number .__
and altitude of peezometric surface and altitude of piezomrnetric surface 20 '
*2T



I l--' --02
Flowing well showing well number and Lne showing approximate altitude of the
altitude of piezometric surface piezomrnetric surface in feet above mean\'


s i ev el,




Figure 26. Map of Manatee County showing the piezometric surface in June 1955. .






REPORT OF INVESTIGATIONS No. 18


in figure 26 shows that the low-pressure trough in the Palmetto-Palma
Sola area had expanded and deepened as a result of the increased
withdrawals of water from irrigation, industrial, public supply, and
domestic wells. The depression shown by the 20-foot contour line, in
the northern part of the coastal area, was caused by the combined
drawdowns of a large number of irrigation wells.
Depth to Water Level Below Land Surface: Figure 27 shows the
areas of artesian flow and the approximate depth to water, below land
surface, in wells that penetrate the Floridan aquifer. It is based on the
piezometric surface in June 1955 (fig. 26).
The areas of artesian flow are along the coast and in the southeastern
part of the county, and they extend several miles upstream along the
valleys of the major streams. There are several isolated areas within
the areas of artesian flow where the land surface is relatively high and
wells will not flow.
In most of the county water levels are less than 25 feet below the
land surface but in the northeastern part of the county they range in
depth from 50 to more than 75 feet.
Temperature: The temperature of the earth's crust increases with
depth at the rate of about 1lF for each 50 to 100 feet. The tempera-
ture of ground water generally increases with depth at approximately
the same rate.
Measurements of the temperature of water from many wells were
made during the investigation. The temperature of water in formations
less than 100 feet deep is generally between 740 and 750F, and that
of water from the Hawthorn formation is between 750 and 77.5F.
The temperature of water from the Tampa formation generally ranges
from 77.50 to 790F, according to the depth of the principal producing
zones and the proportion of the total yield of the well that is obtained
from each zone. Water from wells that penetrate the Suwannee lime-
stone and older formations ranges in temperature from about 79 to
more than 84F, according to the amounts of water obtained from the
various producing zones in both the Tampa formation and the Suwan-
nee limestone as well as in the older formations. Water samples taken
with a deep-well sampler indicates that the temperature of the water
in the Suwannee is 810 to 82F (fig. 12).
The temperature of the water in the Hawthorn and older forma-
tions generally increases in the direction of dip, because of the in-
creased depth of the various producing zones.


47








r





35.















2'-
w*


Figure 27. Map of Manatee County showing the area of artesian flow and the depth
to water in June 1955.


' C EXPLANATION

AREA OF .s c
ARTESIAN FLOW
WATER LEVEL,IN FEET .2
BELOW LAND SURFACE

o- so 2



-25 -5 --

Mars nf
,o..= ,, ;


,ia t


lid






an


* ** ** *Q @ SQ *


o5 9-a






REPORT OF INVESTIGATIONS No. 18


USE OF WATER
Ground water is the source of practically all irrigation, industrial
public, and domestic water supplies in Manatee County except the
Bradenton municipal supply, which is obtained from the Braden River.
The use of water from that municipal supply averages about 3 million
gallons a day; however, numerous private wells throughout the city
furnish water for lawn irrigation, air conditioning, and other uses.
The individual records of 865 wells are published as Florida Geo-
logical Survey Information Circular No. 19 and their locations are
shown in plate 1 and figure 2. The wells that penetrate the Floridan
aquifer are generally between 350 and 600 feet deep. They range from
3 to 12 inches in diameter, but most of them are 6 to 10 inches in
diameter. They are cased to depths ranging from about 25 to more
than 100 feet. In addition to the surface casing, some wells are lined
with an inner casing to prevent the caving of sand from the Hawthorn
and Tampa formations. The wells generally yield several hundred
gallons per minute, but the yields differ according to the permeability
of the aquifer, the diameter of the well bore, and the thickness of the
aquifer that is penetrated by the well.
Shallow wells range from about 25 to more than 200 feet in depth
and from 19 to 6 inches in diameter. Most domestic wells are two
inches in diameter and yield about 30 to 75 gpm.
There is no practical method for determining accurately the average
daily use of water in the county, because of the large variations in daily
and seasonal withdrawals, and the fact that accurate records of with-
drawal are available for only a few of the many wells. It is roughly
estimated that the average daily use of water in Manatee County is in
the range of 15 to 20 million gallons.

QUANTITATIVE STUDIES
The withdrawal of water from an aquifer creates a depression in
the water table or piezometric surface around the point of withdrawal.
This depression generally has the approximate form of an inverted cone
and is referred to as the cone of depression. The amount by which the
water surface is lowered at any given point within this cone is known
as the drawdown. The size, shape, and rate of growth of the cone of
depression depend on several factors: (1) the rate of pumping, (2) the
water-transmitting and storage capacities of the aquifer, (3) the in-
crease in recharge resulting from the lowering of the water surface,
and (4) the decrease in natural discharge due to the lowering of that
surface. The yield of the Floridan aquifer in Manatee County is limited
by the extent to which the piezometric surface can be lowered without






FLORIDA GEOLOGICAL SURVEY


impairing the quality of the water or making the cost of obtaining it
prohibitive.
The principal hydrologic properties of an aquifer are its capacities
to transmit and to store water, for all aquifers serve as both conduits
and reservoirs. An artesian aquifer functions primarily as a conduit,
transmitting water from places of recharge to places of discharge; how-
ever, it is also capable of storing or releasing water, by expansion and
compression.
A measure of the capacity of an aquifer to transmit water is the
coefficient of transmissibility. In customary units, it is the quantity of
water, in gallons per day (gpd) at the prevailing temperature of the
water, that will flow through a vertical section of the aquifer one foot
wide and extending the full saturated height, under a unit hydraulic
gradient. The coefficient of storage is a measure of the capacity of an
aquifer to store water, and is defined as the volume of water it releases
from or takes into storage per unit surface area of the aquifer per unit
change in head normal to that surface.
Pumping Test: A pumping test was made in August 1955 to deter-
mine the transmissibility and storage coefficients of the Floridan aquifer
at one location in Manatee County. Well 34-30-1 was pumped at the
rate of 1,000 gpm for a period of 123.5 hours, beginning at 11 a. m. on
August 22 and ending at 2:30 p. m. on August 27. Water levels were
measured periodically in wells 34-30-2, 34-30-3, and 34-30-4 (fig. 28)
throughout the period of pumping, to determine the rates and magni-
tudes of drawdown at different distances from the pumped well. After

N



EXPLANATION
Pumped well
0
Observatlon well
0 5 ,O0 FEET
34-30-3



34-30- 2 34-30-I


Figure 28. Sketch of pumping-test site, showing location of pumped well in relation
to observation wells.















WELL 34-30-4, 7 MILES NORTHEAST OF BRADENTON ..-- ..
**** --"... ... .. .



4... ................. ...____.____



WELL 34-30-3, 7 MILES NORTHEAST OF BRADENTON .
"L 3 7 M N O B .








22_ 23 24 _25 26 2729


' .. .-AUGUST, 1955-
i 22, 2> 3 24 I 2S3 2 6e i 27 2 8t 29 o
___________________________________________________AUGUST. ,19SB__________________________________


Figure 29. Graphs


showing drawdown and recovery
wells during pumping tes


of water levels in observation


PCi
0


0




C02

z






FLORIDA GEOLOGICAL SURVEY


pumping stopped, measurement of water levels in the observation wells
was continued for about 72 hours. Hydrographs prepared from these
water-level measurements are shown in figure 29.
The Theis graphical method (Wenzel, 1942, p. 87-89) was used to
compute the transmissibility and storage coefficients from the draw-
downs in the observation wells. This method relates the drawdowns
in the vicinity of a discharging well to the rate and duration of dis-
charge and is based on several simplifying assumptions, including the
following: (1) the aquifer is of infinite areal extent and is uniform
in thickness, (2) the aquifer is homogeneous and transmits water with
equal facility in all directions, (3) the discharge well penetrates the
entire thickness of the aquifer, (4) there is no recharge to the aquifer
in the area of influence of the discharging well, and (5) the aquifer is
losing water through only the discharging well.
As shown in figures 30 and 31, the data for each of the observation
wells plotted as a separate curve and the upper part of each curve fell
below the type curve. These deviations indicate that the aquifer does
not closely conform to one or more of the conditions assumed in the
This e(llation. The downward deviation of the data curves from the
type curve during the latter part of the test is an indication that the
a(quifer was receiving recharge probably from the overlying Haw-
thorn formation. The data curves were analyzed by using a leaky-
aquifer type curve (unpublished) developed by H. H. Cooper, Jr., of
the U. S. Geological Survey, Tallahassee. The curve for well 84-30-3
best fitted the leaky-aquifer type curve. The results obtained by using
data for well 84-30-3, therefore, are believed to be most representative
of the Floridan aquifer in the area of the pumping test.
The coefficients of transmissibility and storage computed by match-
ing the observed-data curves against the type curves are as follows:
Coellicient of Transmissibilily Cocificient of Storage
Well Drawdown Recovery Drawdown Recovery
31-30-3 100,000 96,000 l.lx10- 1.4xl0-'
314-30-4 140,000 140,000 4.3x 10- 4.3x 10-
34-30-2 460,000 480,000 1.0x 10-" 8.7x10-4
The data for well 34-30-3 were also analyzed by a method devised
by Cooper and Jacob (1946, p. 526-534), which gave a transmissibility
of 100,000 gpd per foot and a storage coefficient of 1.lx10-' (fig. 32).
Theoretical Drawdowns: The results of the pumping test indicate
that the transmissibility coefficient of the Floridan aquifer near the test
site is about 100,000 gpd per foot and the storage coefficient is about
0.00014. The coefficients of transmissibility and storage may differ con-
siderably from place to place, and because of this, it is not practicable to


52









,3 2 3 S 365 7


39 2 3 4 S 6 ?6 91 2

-: ;."L .. 1 : i [ : i: i .-I .ki-.I .'- *. ;|l;.i. .:.


3 4 S


1 PONT 7


S7 s9


.ti:L .-!_ -c L t


l.; 4 1 :2 I '.,.:II:i.!.I! ;F.T.Ti .j: LL.::... Fi' : j Ii +


I* I 7 3: 9.1-- 97=


.___.-_: _____.. _...:... ..:... :.... .. . .._____'"___ _'__'_ .-.'7 i


:1:74 _____ nfl-L


L4Tf- i "


)-- .

o n
ti

2a
z"






o-
0.
7.

S
4.




2




0.01


.~~~~ t.1.. '1 iii II: ~~


S* "-- ---- -


S. : .;.: ....:.. .,. .. ... ,.aC.i L1 ::KI.: L.4'-V1 .I~4


I.=.. :r: t :
,.'-"'-'. *4.:


T I tC ; i i ; l .I i i i


-t~~~o..*O 6:,- ~ --- -9~ V'?Ir


L.s r"- ki*** ih : Iw,


I Ia l 4 A


;~P4TI~tJ


:- .::; .-; ; :::I- -t .-: .. :: .. :.. f : ::-. 4 -


-tLitiJ .W'~


A. ;:*I


it -
4yin!7.

iu:uihj:W


3 4 5 7 i .-


Ls *---sr *** !E.^**^ ***s


F i ".'- ".i ".-.&I -Lt -I


3 45 6 7 s i
t/rt (days/ft!)


. ..: ::::::.::;::.:... ... .


~i~i~ii~;Li~i~ii~ie~iiii-ii-t~t iiiliijii:ililii:i~t~


I:7.


.: .. ; :..... .


n. -:- if iIi K ...:



li.?!!!!4- 1 pt!
rumlitil~~~~~~~- M--_... ....... .. ..


3 4 S6 7 8


EXPLANATION

0 = 1,000 gpm
W(u) = 1.0
u = 0.1
114.6 0QWu)
T= s

1.87 r'
o
Well 34-30-3
s = 1.13 feet t/r'= 23 x I0-
T =100,000
S=LI x lO"4

Well 34-30-4
s=0.8 foot t/r =5.6 x 10"
T= 140,000
S=4.3xl0
0
Well 34-30-2
s=025 foot$ t/r== 4.1x 1o
T = 460,000
S =1.0 910O


2 3 4 167


Figure 30. Logarithmic plot of drawdowns in observation wells versus t/r'.


-=- ... -


4 5 6 7


0

i.

7 0
6 ^
5 -





I Z
3






, 9

$ 1Z
I Z


....i...L..ic


- i~ii~~: :~lii~!. l~ ~~ I MI


I i ;.L r .- : '. -


. . . .


'i-S;":;-


,-T


i i r 1 )'~) iirr!: ~1 "'~;-C~" t~


' ~'


---


------


.4


a


L


I I i I b -- --- k,, 1- Lii tL 1 IF '


-- --


T


.. '.


r~ irr;;rrl i i (i1l !11(1111111:111111 11111( 1 ~) I it Lt )


iii~iii~ri-i~tii~L~~


- 1 t'l 1.


i i-h. SH.M, il i :i 1 L-=m =f--


'


--- -- -~~-- -- -- -


, I '


.


: *-l I I. -. 1- I*. A I.+ii. .4 .-*.i


~if-iii~iit'i:~-~~~~''-~:~~~"::'~'~t~ii


4 .$ S 1*f1


3 4


7 9.1


I I. .. .1 .1 _


; t


* :


71


:-r.: L


I '.+ .- : ," !. I


I ':T -."- I: : ,.


7-


i :i I 8: i i. I i i i :: i i i


-


L~ii iT~Ii~i::i~~ii i Ili~i:l! n-~,~~ l~-i~~ii~iiit'il'~. i~ii~~~i~~j iii~~_~;~ i~;:~;~.i~ i~~:tImest~t


ID]-7 7!


,1 i '.'*.T l '- I


r: :t;i;n-.i;:;.


I


*S ~S : ; i : ::; :.*:::: ;;::;.* I.;;*:'l .l) .:::=f -^


.1


F-?. .


--


f! !iit*[ \t\ i';l- t..


~~1 i fi I S.i i i iiirii~siiii:ii:i::riirit:i'::i::~'~f~ i


r-,;


0 Hiim MEM ME


2 3 4 6 7


t








t/r' (dOys/ft.')


S *6 7 8 %-.


Figure 31. Logarithmic plot of recoveries in observation wells versus t/r'.


04
0


0


ibo6


- 4-5 I6 75s1 -,


3 4 1 8t *5 1-


s 6 a r lbb
















IJ
Ld










5

6-

L



0.001
5-




6- OI


Time since


Figure 32. Semilog plot


pumping stopped (days)


of recovery versus t for well 34-30-3, seven miles northeast
of Bradenton.


0.01 0.1


0

Z





CO

0

oz


1.0






FLORIDA GEOLOGICAL SURVEY


predict drawdowns in one place on the basis of aquifer properties deter-
mined in some other place. However, in order to illustrate how water
levels are affected in the vicinity of a pumping well, figure 33 was con-
structed. This figure shows theoretical drawdowns in the vicinity of a
well pumping at the rate of 1,000 gpm from an aquifer having a trans-
missibility coefficient of 100,000 gpd per foot and a storage coefficient
of 0.00014.

QUALITY OF WATER
The water that falls on the earth's surface as rain or snow is practi-
cally free of dissolved mineral matter except for small quantities of
atmospheric gases, smoke and dust. Therefore, the mineral constituents
and degree of mineralization of ground water depend generally upon the
composition and solubility of the soil and rocks through which
the water passes, and upon the time of contact. In some cases mineraliza-
tion of ground water may result from the mixing of relatively fresh water
with highly mineralized, residual sea water within the water-bearing
formations.
Chemical analyses of the water from 137 selected wells in Manatee
County (fig. 34) were made by the Quality of Water Branch of the U. S.
Geological Survey (table 5). The wells range in depth from about 50 to
more than 700 feet. In addition to these analyses, the chloride content
of water from about 750 wells and the hardness of water from 287 wells
were determined during the investigation and the results are published in
Florida Geological Survey Information Circular No. 19.
Constituents and Properties: The principal mineral constituents and
physical properties of water from wells in Manatee County are discussed
below. The concentrations of mineral constituents are given in parts per
million 1 ppm is approximately equivalent to 8.34 pounds per million
gallons of water. Specific conductance is expressed in micromhos at 25C,
and the hydrogen-ion content in standard pH units. The tolerable limits
given for the ions, unless stated otherwise, are taken from standards
prescribed by the U. S. Public Health Service (1946).
Calcium: Calcium (Ca) is dissolved from limestone, which is predom-
inantly calcium carbonate, by water containing carbon dioxide. Calcium
is a principal cause of hardness in water.
Water from wells that penetrate the Suwannee limestone or older
formations was generally a composite of water from the Tampa formation
and the Suwannee limestone and contained 50 to 320 ppm of calcium.
The calcium content of water from the Tampa formation, ranged from
50 to 325 ppm. The Hawthorn and younger formations yielded water
having a calcium content of 36 to 204 ppm.
















S15






25 j Computed on the basis of: 0
25
T= 100,000 gpd / ft.
S= 0.00014
0 Q=I,000 gpm
30r- I I F i I- I I -_ I- ii i --A l
1.0 5 10 50 100 500 1,000 10,000 100,000
DISTANCE, IN FEET, FROM PUMPING WELL
Figure 88. Graph showing theoretical drawdowns in the vicinity of a well being o
pumped at a rate of 1,000 gpm for selected periods of time. 1












~
-- -.---.---- -.- -. I
____________ 2-----

/ -.--.----
- ---- -?r -
-F


-I.-'
S-U -
~ I


~/KIiL.


I to
~


I ii wrnTe


1 9 1 1 1


--, I A I


EXPLANATION


:' i


JLLLI+ ~Ij
~ i44~~
I.
0
I LL


I __


: ,:14


: I


I.
ii


I 1


I

1


a
=
C


a
U


0


z
C

0
'7.'. ~

C


Figure :34. Mapl of Manatee County showing wells sampled for chemical analysis
and location of line A-B in figure 44.


rL1


16" or


ttt


=sop 0---FT


3b


1-4


' '


i


RR 1 1


1 -


- --


cc 70 o.


-L


- m J


Lm-Lmm"


St 7, w


k/T


1


I


'


aw






REPORT OF INVESTIGATIONS No. 18


Magnesium: Magnesium (Mg) is dissolved principally from dolomite
or dolomitic limestone, and, like calcium, it causes hardness. As magne-
sium is one of the principal mineral constituents of sea water, ground
water that has been contaminated with sea water has a relatively high
magnesium content.
The magnesium content of water from the Suwannee limestone and
older formations ranged from 28 to 167 ppm. Water from the Tampa
formation contained 13 to 118 ppm, and water from the Hawthorn and
younger formations contained 5.8 to 99 ppm, but generally less than 50
ppm.
Sodium and Potassium: Sodium (Na) and potassium (K) are dis-
solved in small amounts from many types of rocks but they constitute
only a small part of the total mineral content of fresh ground water. The
sodium content of water that has been contaminated with sea water is
generally high, as sea water is primarily a solution of sodium chloride.
Water from the Suwannee and older formations contained 0 to 628
ppm of sodium and potassium; water from the Tampa formation con-
tained 0 to 246 ppm; water from the Hawthorn and younger formations
contained 0 to 218 ppm.
Bicarbonate: Bicarbonate (HCOa) in ground water is obtained from
the solution of limestone and other carbonate rocks by water containing
carbon dioxide.
Water from the Suwannee and older formations has a bicarbonate
content of 102 to 264. ppm, and water from the Tampa formation had a
bicarbonate content of 162 to 270 ppm. The bicarbonate content of water
from the Hawthorn ranged from 48 to 557 ppm, but it was generally
higher than that of water from the Floridan aquifer.
Sulfate: Sulfate (SO.) in ground water may be due to the oxidation
of sulfides or to the solution of sulfates of calcium, magnesium, sodium,
or potassium that were deposited by the sea. Large quantities of sulfate
salts in water may impart a bitter taste and have a laxative effect. Sulfates,
of calcium and magnesium cause boiler scale. The tolerable limit of
sulfate in drinking water is considered to be about 250 ppm.
Water from the Floridan aquifer in Manatee County is generally high
in sulfate. Wells penetrating the Suwannee and older formations yielded
water having a sulfate content of 22 to 803 ppm (fig. 35). Water from
the Tampa formation contained 22 to 750 ppm (fig. 36). Water.fi'om the
Hawthorn and younger formations contained 5 to 550 ppm, but generally
less than 200 ppm.
Chloride: Chloride (Cl) in small quantities may be dissolved from
most rocks and soils and is found in large quantities in water that has







r45' 40 35' 8230 25 ___2C 82*1'
273 7 27-v-
?7"3a'---l-' --* l" -' "" f--,r ; -T- *- -- -- -- -.- -- -- -- --,- -- -.-- -.-- --_ ,,.-"-


n 7 I .. 7 :6/ <
:== _T'J i --"^ ^^ ^i~y -
825 4 3 25 2









S27 A C30, 3











8245 40' 35' EXPLANATION o 30 25


Figure 35. Map of western Manatee County showing sulfate content of water from





403


il~LL12~

~-~--~3~~CO~"


6ib 1;


823 20 8218'a


I-
!_


'1'

- I-
i I


'I


'I I


- %%


ANNA MARA






EXPRADENTON 20' 821,










i A I U -
--., --I








.A. .. 2 .7_ .02 ._ .3 *._ "


3 "pcer miIon
251-500


82*30'


-501-600


S more then 600


Figure 36. Map of western Manatee County showing sulfate content of water from
the Tampa formation.


K%~jLZ~


~r~t~f~l~


27


82 45'


L'J' 250 or less


G/1


% %


0
0


z
2'







z
0
P

o


I


- I


'-----~~--


1 Z =


--- -' -;--~ "'


L.Wev" I I I


-"JL" _p_, .


;r I


Axql.


.ww -


_- x f


VM


I


J


823d0'


20'


8201'


27'


20' 8, -






1 41,()All C) OtAG CEtCLAIC SunvEY


been contaminated by seal water. Chloride salts do not generally decrease
the potability of water except when present in sufficient quantity to cause
a saltN taste. Water high in chloride content is very corrosive to metal
surfaces and is harmful to most cultivated plants.
The chloride content of water from wells in Manatee County is dis-
cussed in detail in this report under the heading "Salt-Water Contamin-
ation." The chloride content ranged from 12 to more than 1,500 ppm in
water from wells that penetrate the Suwannee limestone and older forma-
tions (fig.37) and from 10 to 920 ppin in water from wells that penetrate
only the Tampa formation (fig. 38). The chloride content of water in
the Hlawthorn and younger formations ranged from 8 to more than 400
ppm (fig. 39) except at the north end of Anna Maria Island, where it
was as much as 44,000 ppim. The extreme saltiness of the water is
apparently due to the solution of mineral salts that were deposited
in the formation.
Iron: Iron ( Fe) occurs in almost all rocks, but the quantity dissolved
by ground water is generally very small in comparison with other con-
stituents. Iron in water causes stains on plumbing fixtures and clothing,
and in concentrations greater than 0.5 to 1.0 ppm it can be tasted. Iron
can generally he removed from water by aeration and filtration.
Fluoride: Fluoride (F) is found in very minor amounts in most ground
water. Water containing fluoride in excess of 1.5 ppm may cause mottling
of the enamel of children's teeth during formation (Cox and Ast 1951, p.
641-648); however, il concentrations of 1.5 ppm or less, fluoride tends
to reduce tooth decay in children and is added to many public supplies
for this reason.
Dissolved Solids: The dissolved-solids concentration represents the
approximate anmout of mineral matter dissolved in the water. Water
containing less than 500 ppm is generally of good chemical quality,
according to U. S. Public Health Service standards, and water contain..
ing up to 1,000 ppm may be used for public supplies if a less mineralized
water is not available.
The dissolved solids of water from wells penetrating both the Suwan-
nee limestone and older formations range from 382 to 3,560 ppm. The
concentration of dissolved solids in water from these wells is shown in
figure 40. Figure 41 shows the concentration of dissolved solids in water
from wells penetrating the Tampa formation, the range being from 376 to
1,700 ppm.
Water from the Hawthorn and younger formations had a dissolved-
solids content ranging from 216 to 1,620 ppm, but most of the water had
350 to 6)00 ppn.





S' 40' 35'2________253' ,2 '
2 /,"7*3h,,_.._







A M A -i VNH







_. .*' ____,_.. : ,, ___ __--- ,----
27 30' 353 ... 8" .,' C ,^,






...5 .-.' "ene ate t-
OVI























Figure 37. Map of western Mlanatee County showing chloride content of water
from wells that penetrate the Suwannee limestone and older formations.







8 245' 0


r1 we


EXPLANATION


I] 25 or less

Figure 38. Map


2326-50


25'T








1%1
2 c i


2 7059


\ N
N
'\ N N N
N N N
N. N. *\ *\*
.~ N N N
N N \ -


82*30C


S101-250


N N. \ '~
~2723'
20 82~18'

~ rr~re than 250


of western Manatee County showing chloride content of water from
the Tampa formation.


C,,




t!1





2?


82r45'


40'


36i21 3 liles I___


ANNAI MARIA



2750': -




sBRA DE' '" -N T ""
BEACH .^ EC6

25 i .... -iy f.
rS ^^^^^^


-_ .'* I i\ !" "r"""r" ~ "" c ~


z27245-
8245'


50 or less


_35' !2"3f 25' 0' 2*2d


1Thfl77i7VTh~1


X/


- J/-.- I !/ -f 9 -


I


.1
.. l i


Ti
F



-j


MAAIME
COU27-30'


N


- I A -%--LA-L- -- l T I


35' EXPLANATION. 830'
FRts per million
0
51-100


--


71


'- -- i -;-- ''23'


more than 100


Figure 39. Map of western Manatee County showing chloride content of water from
the Hawthorn and younger formations.


V


RL|


i I


I I I I "),


II 1 1 1 1 1 1 1 1- I r pr r


I t/ r I r I i .I I74


i a~ 7~l- i0=411I r 1--~S5 2


35


r--j


ml


1





L.


* i Oi.A'j.^A^y'^A.'ilt.yv


' -~~-I'-- ---~-- ~


rr-


I-


I I ---I I


I


fNIL


_JAIR


al







8 40 35' 6230 20 82
-,, -1 ,,- 1 3










COO I J















LONG! -
S245 40' EXPLANATION 30 25 20 '








Ports per million

s500 or less 5o-75o l75-Ipoo ^% o0-I25o -o 5- .,morI am 10oo

Figure 40. Map of western Manatee County showing concentration of dissolved
solids in water from wells that penetrate the Suwannee limestone and
older formations.
older format-ions.




20' 82*8


-1L 7
i -1 7- Ills


I I I


Ikc I


NNA MAA


T PAPMASO
FPAMASOL VA
27030 -r -!--
I


1M'i /


II


I'


"/i\


I I 1 -I-k


(LLrh


5uvif


S40' 27*3
LJ41


'717F~{~-r~ PARRISHlY
V1Ae" P -I l


~** N


7'V1


el -I


_____ ~ TN~ ':
11K. N
~ N ,r
N N~


N


- N,


yE ~!' :27*30'
Ne


IA'A
____ / < *
BRADENTON~ ~N N N
N EYAC'*
N, ;-'..




-, ~ 25`258
^^,&A 0' 'A 1- Aore vot e230'500


0 s500 or less


C501-o000


Pcrts per mtlr:~or
El .oor- r250


0j a5t-r5oC


Figure 41. Map of western Manatee County showing concentration of dissolved
solids in water from the Tampa formation.


270


I
r J





824"5


7 mo ftn 1,500


I


m i j -.


-- -- ---------


-4 1 A 6' 6 1 P


'i- -


W I JoF I Z A Z L %%I I I


- --- -- --


ib' .


A I % %


.m6- 0 Ims- i


t~i-i I, i


.tlovi, IN %7


7'c r~ 1 1


4-4 1


~dfY~i


i F-RF


z I V-01-Y I f


--


C-


I-


a90'0


E.


11


v


Czi *aF


. J% /


/i


rvrl- 11.


M:T


' 1 J~'
*\2-\


7
16






68


Hardness: The hardness of a water is due almost entirely to the salts
of calcium and mIagnesium. Hardness caused by calcium and magnesium
equivalent to the carbonate and bicarbonate is referred to as carbonate
hardness. lardness caused by the chlorides, sulfates, and nitrates of
calcium a(lnd mnagnesiumn is known as noncarbonate hardness. The most
noticeable effects of hardness are the formation of soap curds and the
lack of suds when soup is added to the water. Hard water also causes a
scale il oilers or vessels ill which the water is heated.
Water having a hardness of less than 50 ppm is generally satisfactory
for most purposes. Hardness between 50 and 150 ppm does not seriously
interfere with the 11se( of water for most purposes but does increase the
U1s of soap andl is generally ObjectiOnablle to ,people who are accustomed
to soft water. Water having a hardness of more than 150 ppm is rated
its hard andl is commonlyV softened for domestic and other uses.
Figure 42 shows the hardness of water from wells that penetrate the
Suwannitce and older limestones; it ranged from 240 to 1,680 ppm. Figure
43 shows the hardness of water from the Ta111pa formation; it rallge(d
from 228 to 1,09()0 ppm. Wells that did not penetrate the Floridan aquifer
yielded water ranging in hardness from 140 to 916 ppm, bult the hardness
was generally less than 500 ppm.
Sprcifict/fr ( idclamn:c: The specific conductance of water is a measure
of its capacity to conduct all electric current and depends on the concelln-
tration andl ionization of the minerals in solution, It is useful in determin-
ing the mitieralization of a water. The specific conductance of water from
the Floridlan aquifer in the county ranged from 478 to 5,260 micromhos.

Hydrogen Sulfide: Hydrogen sulfide (H. S) is a gas that gives water
ali objectionable odor andl causes corrosion of plumbing. It can be
remove ,d ib aeration. Water containing hydrogen sulfide is often referred
to as "sulifur water." No determinations were made of the hydrogen
sulfide content of water from wells in Manatee County; however, the
gas is present iln water from mosatwells that penetrate the Hawthorn
and older formations.
Ilydrogen-ion Concentration (pll): The pH value of a water indicates
the instantaneous concentration of hydrogen ions. Water that has a pH
of 7.0 is said to be neutral. Water having a pTH of less than 7.0 is acidic
and may be corrosive; water having a pH greater than 7.0 is alkaline and
not generally corrosive. The pH of water from the Floridan aquifer in
Manatee (Coumnntv ranged from 7.2 to 8.5, and the pH of water from the
younger formations ranged from 7.3 to 8.2.


Ft'lom)llA GEOLO(GICALI SUR\VEN











J-
eA ,er?' a7 ~* --- ero





' 4-- 3 5 e 2V_.o:wr l ^ a












,250 or ess -. '
^25I- 500 '7
,7 5 I : '^ ^4 A 75 i'." r'"





// r^e stta, / /
/ ./ /-- --

ES ] o,1- ,'o^ ^^, / /, ,, .., --



























:.0r less ;
m,25.-"500
- ,'*. -- "," ^,- "- --'~, 2.. 7* .












Figure 43. Map of Manatee County showing hardness of water from the Tampa
\ '0 7. w.- 7/








501__.o -,5
0
,,,. 7!0

t .i .. !1"" ,tI \ "t
......:,-_. ... ; ,, .,
Figue4.Mpo aae onysownad fwtrfo h ap
i-= ,;,,, ,,,r"m"ti---






REPORT OF INVESTIGATIONS No. 18


SALT-WATER CONTAMINATION
In coastal areas where the water-bearing formations are hydraulically
connected to the sea, the depth to salt water is directly related to the
height that fresh water stands above sea level. The lowering of the water
table or artesian pressure head in such areas may permit sea water to
enter the water-bearing formation and contaminate the fresh water.
Salty water is present in the Floridan aquifer at relatively shallow
depths throughout much of the coastal area of Florida. At some places,
the lowering of the artesian pressure head by the withdrawal of large
quantities of water from wells has caused the encroachment of sea water
into the aquifer. In most of the coastal area, however, the head is suffi-
ciently high to prevent encroachment of water directly from the sea; thus,
the extensive occurrences of salty water are probably due to residuals of
sea water that entered the aquifer prior to Recent time.
The Floridan aquifer was partly filled with sea water several times
during the interglacial stages of the Pleistocene epoch, when the sea stood
above the present level. Since the last recession of the sea, the circulation
of fresh water through the aquifer has been gradually diluting and flush-
ing out the salty water. In much of the coastal area, the flushing
is incomplete and a part or all of the water-bearing formations still contain
water which, although considerably less salty than sea water, is too salty
for most uses. The dilution and flushing of the salty watef will continue
as long as the artesian pressure head remains relatively high. Excessive
lowering of the head will retard the flushing action and may cause an
upward movement of the salty water from the lower zones of the aquifer,
except where such movement is prevented by impermeable beds. If the
head is lowered far enough, the seaward movement of water in the aquifer
will be reversed, and thus will permit sea water to enter the aquifer.
The dissolved mineral matter in sea water consists predominantly of
chloride salts. The chloride content of ground water, therefore, is
generally a reliable index of contamination by sea water. Water samples
from about 750 wells were analyzed to determine the chloride content of
the water in the Floridan aquifer and in the Hawthorn and younger
formations.
The analyses show that in most of the county the water in the Floridan
aquifer has a chloride content of 25 ppm or less. In western Polk County
the water in this aquifer has a chloride content of about 10 ppm, and in
eastern Manatee County, about 15 ppm. It gradually increases westward,
in the direction of ground-water movement. The principal constituents
of water from selected wells that penetrate the Floridan aquifer (see
line A-B in fig. 84) are shown graphically in figure 44, to illustrate the
increase in mineral content of the water as it moves toward the coast.






FLORIDA GEOLOGICAL SURVEY


As shown in figures 37 and 38, the water in the Floridan aquifer in much
of the coastal area has a chloride content ranging from 26 to more than
500 ppm. The areas of highest chloride content are generally the areas
of lowest artesian pressure head (fig. 25, 26); however, the mean artesian
head along the coast is sufficiently high to prevent sea water from entering
the aquifer at depths less than about 650 feet.


28-34-2 28-31-2
WELL NUMBERS


Figure 44. Graph showing the principal constituents of water from selected wells
along line A-B in figure 34.

Two wells on Mullet Key, about five miles north of Anna Maria Island,
yield water from the Floridan aquifer having a chloride content of about
900 ppm. A well on the Sunshine Skyway, about three miles south of
the Pinellas County peninsula, yields water from the Floridan aquifer
having a chloride content of 1,350 ppm. The relatively low chloride
content of water from these wells indicates that most of the salt water
has been flushed from the upper part of the Floridan aquifer in an area
extending a considerable distance offshore.
As shown in figure 38, the water from the Tampa formation contains
less than 250 ppm of chloride throughout most of the coastal area. This in-
dicates that most of the salty water has been flushed out by the circulation






REPORT OF INVESTIGATIONS No. 18


of fresh water, although a few wells at the northern end of Anna
Maria Island yield water from the Tampa formation containing as much
as 460 ppm of chloride. The flushing of the salty water from the Suwan-
nee limestone and older formations is less complete than it is from the
Tampa formation (fig. 37, 38). The water from wells that penetrate the
Suwannee limestone and older formations is principally a composite of
water from the Tampa formation and Suwannee limestone, and it contains
less than 500 ppm of chloride in most of the coastal area. However,
several deep wells in the vicinity of Palma Sola Bay yield water having a
chloride content ranging from about 1,000 ppm to more than 1,500 ppm.
The chloride content of the water in the Suwannee limestone and older
formations is probably much higher than indicated by the analyses of the
composite samples.
Water samples were collected at various depths in selected wells to
determine the chloride content of water from the different producing
zones. As indicated by graphs in figures 12, 15, 45, and 46, the saltier
water enters the wells from the deep producing zones and is diluted by
fresher water from other producing zones as it moves up the well bore.
For example, the analyses of samples collected in well 28-41-4 (fig. 12)
show that the chloride content of water from the Suwannee limestone at
the bottom of the well was about 2,400 ppm, whereas at a depth of 500
feet, where additional water entered the well, the average, chloride con-
tent was about 900 ppm. At a depth of about 380 feet, where a consider-
able quantity of water entered the well from the Tampa formation, the
average chloride content was about 550 ppm.
Periodic analyses of water samples show that the chloride content of
the water changes with changes in artesian pressure head. Generally, a
decrease in head is accompanied by an increase in chloride content, and
vice versa (fig. 20, 22). This relationship indicates that the lowering
of the head causes an upward movement of the salty water from the deep
formations. The relationship may also reflect variations in the proportion
of the total yield of the well that is obtained from each producing zone.
During periods of heavy withdrawal, the head in the Tampa formation
in localized areas is slightly less than the head in the deeper formations.
During such times, the proportionate yield from the deeper formations is
increased, and the chloride content of the water is higher.
Although the periodic determinations of chloride content indicate that
the lowering of the artesian pressure head causes an upward movement
of salty water from the deeper formations, they do not show any lateral
expansion of the contaminated area. However, a continued decline of
the piezometric surface in the coastal area will eventually result in lateral
encroachment from the ocean. Lateral encroachment can be prevented


78








14 FLORIDA GEOLOGICAL SURVEY


3 SELF- POTENTIAL RELATIVE RESISTIVITY CHLORIDE CONTENT
AGE 10 mv 25ohms (ports per million)
..- 200 300 400 500

0- aand-C,





100 -- 1..-- I00






-00 --------- ------- i ---- ---- 0
4 z
to








3* 500 -- 300-- 400
i 0 i








400 4 00





S500 -00
5u 0


.600


Figure 45. Graph showing data from well 27-36-1, four miles southwest of Bradenton.






BRPOtT OF INVESTIGATIONS No, 18


CHLORIDE CONTENT
(parts per million)
)0 1,500 2,000


TEMPERATURE
(degrees
Fahrenheit)
80 81
i-- -10


1001 ---- 00
J


-J

U)

< 200 --- 200



O
0


I-
U 300- 300
LL
z













500 500




Figure 46. Graph showing chloride content and temperature of water from well
29-40-8, two miles north of Cortez.


75






FLORIDA GEOLOGICAL SURVEY


and upward encroachment retarded by avoiding excessive drawdown,
through the use of proper well spacing and controlled discharge rates
in the coastal area.
SUMMARY AND CONCLUSIONS
The investigation of the ground-water resources of Manatee County
consisted primarily of collecting and evaluating data from more than
900) private and public wells. The principal results are summarized
below:
The county is underlain below depths ranging from about 175 to 875
feet, by a thick section of limestone consisting of formations of Eocene,
Oligocene, and Miocene ages. The limestone formations penetrated by
water wells are the Avon Park limestone and the Ocala group of Eocene
age, the Suwannee limestone of Oligocene age, and the Tampa formation
of early Miocene age. These formations are overlain by the Hawthorn
formation of middle Miocene age, which consists of interbedded marl,
limestone, and sand. The Hawthorn is overlain by deposits of sand, clay,
shells, and limestone of Pliocene and Pleistocene age, which range in
thickness from a few feet to about 90 feet.
Water in usable quantities generally occurs in all formations pen-
etrated by wells. The sand, limestone, and shell beds of Pliocene and
Pleistocene age yield water to many domestic wells. The water in these
deposits is replenished by local rainfall. The Suwannee limestone and
Tampa formation, which form a part of the Floridan aquifer, are the
principal sources of ground water in the county. The water in these
formations occurs in permeable zones separated by relatively impermeable
layers which retard the vertical movement of the water. The water is
replenished by rainfall in northern Polk County and, possibly, in north-
eastern Manatee County. The Hawthorn formation serves as a confining
layer for the water in the Floridan aquifer. Beds of sand, shells, and
limestone within the Hawthorn are the source of many small irrigation
and domestic water supplies.
The artesian pressure head of the water in the Hawthorn formation is
generally several feet lower than that of water in the Floridan aquifer.
Because of this difference in head, water from the Suwannee limestone
and Tampa formation leaks upward into the permeable beds in the Haw-
thorn formation through wells that are open to all these formations. The
depression in the piezometric surface in the vicinity of Palma Sola (fig.
25) is probably due in part to such leakage through unused irrigation
wells.
Water-level records show that significant changes in artesian pressure
head result from daily and seasonal variations in withdrawal of water
from wells. During periods of heaviest withdrawal, the piezometric






REPORT OF INVESTIGATIONS No. 18


surface is lowered four or five feet throughout the county and as much
as 10 feet at some places. The increase in both seasonal and perennial
use of water since 1948 has resulted in a progressive decline of artesian
head in parts of the county and a progressive increase in the magnitude
of seasonal fluctuations.
Because of the decline in head, pumping is necessary in many areas
where sufficient quantities of water were formerly obtained by natural
flow. In other areas, the depth of the water below the land surface has
exceeded the lift capacity of centrifugal pumps, and turbine pumps must
now be used.
The chloride content of the artesian water in most of the county is
about 15 to 25 ppm, but in a zone about 3 to 10 miles wide along the
coast it ranges from 26 to more than 1,500 ppm. This indicates that the
ground water is contaminated by salt water. The salty water is probably
a diluted residue of sea water which entered the aquifer during Pleisto-
cene times and which has not been completely flushed from the aquifer.
The mean artesian head along the coast is sufficiently high to prevent the
encroachment of salt water directly from the sea.
A few wells yield water containing more than 400 ppm of chloride
from the Tampa formation, but the water in the Tampa generally contains
less than 250 ppm of chloride, indicating that most of the salt water has
been flushed out. The flushing is less complete from the Suwannee lime-
stone, in which the water at some places contains more than 2,000 ppm
of chloride. Throughout most of the coastal area, however, the chloride
content of water in the Suwannee is less than 500 ppm. The water in the
Eocene formations along the coast is probably too salty for most uses.
Periodic determinations of chloride content show that the chlorinity
of the water changes with significant changes in artesian pressure head.
Some wells that show a progressive decline in head show also a progres-
sive increase in chloride content, indicating that the lowering of head
causes an upward migration of salty water from the deeper formations.
Little or no expansion of the contaminated area has occurred during
the period of investigation; however, if the piezometric surface continues
to decline in the coastal area, lateral encroachment from the ocean will
eventually result. Lateral encroachment can be prevented and vertical
encroachment retarded by avoiding excessive drawdowns, through the
use of proper well spacing and controlled discharge rates in and adjacent
to the contaminated area.
Water-level measurements and periodic determinations of the chloride
content of water from selected wells should be continued, so that any
changes in the head and chlorinity of the artesian water can be detected
and controlled.


- ---~-L ~L ----IL_






FLORIDA GEOLOGICAL SURVEY


REFERENCES
Anders, R. B. (see Peek, H. M.)
Applin, Esther R. (see Applin, Paul L.)
Applin, Paul L.
1944 (and Applin, Esther R.) Regional subsurface stratigraphy and structure
of Florida and southern Georgia: Am. Assoc. Petroleum Geologists Bull.,
vol. 28, no. 12.
Ast, D. B. (see Cox, C. R.)
Black, A. P.
1951 (and Brown, Eugene) Chemical character of Florida's waters-1951:
Florida State Board of Cons., Division Water Survey and Research,
Paper 6.
Brown, Eugene (see Black, A. P.)
Collins, W. D.
1928 (and Howard, C. S.) Chemical character of waters of Florida: U. S.
Geol. Survey Water-Supply Paper 596-G.
Cooke, C. W.
1945 Geology of Florida: Florida Gecol. Survey Bull. 29.
Cooper, II. H., Jr.
1940 (and Jacob, C. E.) A generalized graphical method of evaluating forma-
tion constants and summarizing well-field history: Am. Geophys. Union
Trans., vol. 27.
Cox, C. R.
1951 (and Ast, D. B.) Water fluoridation a sound public health practice:
Am. Water Works Assoc. Jour., vol. 43, no. 8.
Ferguson, G. E. (see Parker, G. G.)
Gunter, Herman (see Sellards, E. H.)
Howard, C. S. (see Collins, W. D.)
Jacob, C. E. (see Cooper, H. HI., Jr.)
Love, S. K. (see Parker, G. G.)
MacNeil, F. S.
1950 Pleistocene shorelines in Florida and Georgia: U. S. Geol. Survey Prof.
Paper 221-F.


Matson, G.
1918

Parker, G.


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


1950 (and Stringfleld, V. T.) Effects of earthquakes, trains, tides, winds, and
atmospheric pressure changes on water in the geologic formations of
Southern Florida: Econ. Geology, vol. 45, no. 51.
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.
1955 (and Anders, R. B.) Interim report on the ground-water resources of
Manatee County, Florida: Florida Geol. Survey Inf. Ciro. 6.
Puri, Harbans
1953 Zonation of the Ocala group in peninsular Florida (abstract): Jour.
Sedimentary Petrology, vol. 23.
Sanford, Samuel (see Matson, G.C.)


78






REPORT OF INVESTIGATIONS No. 18 79

Sellards, E. H.
1913 (and Gunter, Herman) The artesian water supply of eastern and southern
Florida: Florida Geol. Survey 5th Ann. Rept.
Stringfleld, V. T. (also see Parker, G. G., 1950)
1933 Ground-water investigations in Florida: Florida Geol. Survey Bull. 11.
1936 Artesian water in the Florida peninsula: U. S. Geol. Survey Water-
Supply Paper 778-C.
U. S. Public Health Service
1.946 Public Health Reports: vol. 61, no. 11, p. 371-384.
Vernon, R. 0.
1951 Geology of Citrus and Levy counties, Florida: Florida Geol. Survey
Bull. 33.
Wenzel, L. K.
1942 Methods for determining permeability of water-bearing materials, with
special reference to discharging-well methods: U. S. Geol. Survey Water-
Supply Paper 887.








Table 5. Chemical Analyses of Water from Wells in Manatee County
(Analyses, in parts per million, by U.S. Geological Survey)


Mag-
nesium
Mf e


Sodium
and po-
tassium
(NV +K)


Bicar-
bonate
(HCO) -'


Well No.
i


Date
of col-
lection


Chloride
(Cl)


Dis-


solved
solids


3- 9-55
3- 7-55
3- 7-55
4- 1-55
3-23-55
3- 9-55
3- 9-55
4- 1-55
2-24-55
1-26-54
1-29-54
2-16-55
2-16-55
2-16-55
3- 7-55
3-23-55
3- 9-55
4- 1-55
4- 1-55
1-20-54
3- 7-55
3-23-55
3-23-55
3-23-55
4- 1-55
2-16-55
2-21-55
2-21-55
2-18-55


Hardness as Specific
CaCO; conduct-
ance-
(mi-
SNoncar- cromhos
Total bonate at 25*C)


Calcium
(Ca)


72
212
162
36
140
166
146
94
151
126
149
109
120
186
140
139
154
70
145
170
122
130
141
144
73
192
188
154
252


38 1.6' 208
113 146 !?64
93 96 162
17 55 248
69 29 165
84 12 170
73 .01 167
51 50 236
71 55 166
52 ........ 172
58 ........ 162
20 26 309
18 30 412
91 195 160
78 82 172
67 37 175
78 12 170
34 49 250
45 160 527
103 186
80 78 178
60 49 178
65 35 171
68 32 166
35 51 362
88 114 162
77 65 194
23 26 338
115 171 156


Sulfate
(S04)


135
750
615
15
472
508
412
268
495
385
468
108
25
495
480
475
498
106
124
472
500
475
502
515
55
625
535
126
660


!


20 430-
280 1,700
158 1,270
44 342
49 966
83 1,120
66 940
57 716
97 988
65 860
80 974
32 476
54 534
283 1,530
147 1,130
46 944
51 960
74 606
236 1,110
145 1,100
97 1,010
27 862
24 928
26 936
58 504
217 1,410
149 1,170
90 664
467 1,970


20-10-1
23-38-1
23-38-3
*24-26-1
25-29-2
25-31-2
25-31-7
*25-32-1
25-33-5
25-34-1
25-34-2
*25-34-3
*25-34-9
25-35-2
25-40-3
26-29-3
26-30-3
*26-31-2
*26-33-5
26-35-3
26-41-2
27-28-1
27-29-1
27-30-3
*27-31-2
27-34-1
*27-35-1
*27-35-2
27-35-3


pH


166
860
654
160
498
621
527
251
532


37
707
529
479
565
109
115

425
480
494
30
709
627
201
972


635
2,180
1,610
529
1,220
1,430
1,240
967
1,320
1,140
1.250
728
778
1,980
1,440
1,180
1,250
817
1,650
1,540
1,330
1,110
1,115
1,150
802
1,800
1,580
1,000
2,660


336
994
786
160
633
760
664
444
668
528
614
354
374
838
670
622
704
314
547
690
634
571
620
630
326
841
786
478
1,100


-i
Temper-
ature
(*F)

79
80.5
79.2
79.5
79.5
78.5
80.
78
78.5


79.2
82
80

80.
78
81
79
79.8
74
79
75.5


7.7
7.4
7.4
7.5
7.4
7.5
7.5
7.5
7.7
7.5
7.4
7.3
7.4
7.4
7.3
7.4
7.4
8.1
7.3
7.3
7.4
7.4
7.4
7.3
7.4
7.4
745
7.5
7.5


I


I


0
L0


0q
CA





Table 5 (continued)

Hardness as Specific
Sodium CaCOa conduct-
Date Calcium Mag- and po- Bicar- Sulfate Chloride Dis- ance Temper-
Well No. of col- (Ca) nesium tassium bonate (SO4) (Cl) solved (mi- ature pH
election (Mg) (Na+K) (HCO) solids Noncar- cromhos (0F)
Total bonate at 25*C)
*27-37-5 2-17-55 97 19 20 345 15 46 426 320 138 681 75 7.5
27-38-3 3- 3-55 208 100 101 162 575 296 1,550 930 798 2,100 79.9 8.2
27-38-7 1-20-54 219 88 ........ 166 595 300 1,580 912 ........ 2,120 79 7.4
27-39-4 3- 3-55 120 82 64 195 355 174 1,030 636 476 1,390 78 7.4 .
27-39-12 1-20-54 229 94 ........ 168 682 240 1,650 958 ........ 2,030 80 7.4
27-41-3 1-20-54 134 71 ........ 200 392 112 1,020 628 ........ 1,330 79 7.4 0
28-16-1 3- 9-55 50 28 15 264 22 24 382 240 24 473 79 7.5 P
28-29-3 3-23-55 118 54 29 178 388 21 760 516 370 991 78 7.5 -.
*28-30-7 4- 1-55 113 9.2 26 316 72 30 448 320 61 678 75 7.5
28-31-2 1-28-54 164 69 ........ 168 545 28 1,020 696 ........ 1,250 85 7.3
.*28-32-2 4-1-55 71 27 43 326 19 67 482 288 22 748 ........ 7.5
*28-33-2 4- 1-55 36 20 13 196 14 18 216 172 12 376 ........ 7.4
*28-34-1 3-17-55 229 42 78 250 490 141 1,220 744 539 1,600 ....... 7.4
28-34-2 3-25-55 177 78 47 102 622 94 1,280 762 679 1,570 78 7.9 Q
*28-34-5 3-25-55 107 10 40 317 62 50 486 308 48 724 74 7.3 0
*28-34-7 3-25-55 77 28 29 301 72 34 420 307 61 639 ........ 7.3
*28-35-12 4- 1-55 101 5.8 14 314 21 20 344 276 19 553 ........ 7.5 z
28-37-1 1-20-54 235 97 ........ 216 500 578 1,910 990 ........ 2,880 78 7.3 o
*28-37-9 3-3-55 123 13 25 412 15 44 444 360 23 721 ........ 7.8
128-38-6 5-21-53 326 135 412 160 803 925 2,900 1,370 1,240 4110 ....7.5
28-40-8 1-20-54 158 96 ........ 204 415 232 1,230 740 ........ 1.700 79 7.3
28-41-5 3- 7-55 320 167 414 178 675 1,090 3,220 1,480 1,340 4,580 80.3 7.2
28-41-6 3- 7-55 134 83 70 204 435 148 1,100 676 509 1,400 76 7.5
28-41-7 3- 7-55 110 66 85 224 365 118 1,090 546 363 1,180 77.8 7.9
29-26-3 3- 4-55 52 34 23 209 99 32 376 270 109 604 77.5 7.6
29-26-5 3- 4-55 99 49 16 190 280 25 604 448 293 833 80 7.8
*29-29-3 4- 1-55 38 28 40 232 38 47 354 210 20 561 ........ 7.6
29-29-6 3- 4-55 136 .63 15 174 440 22 804 598 456 1,050 79.7 7.6
29-32-2 1-27-54 168 59 ........ 176 512 27 1.000 664 ........ 1,210 79 7.5
S1Io








Table 5 (continued)


Well No.


Date
of col-
lection


*29-32-5 3-25-55
*29-35-1 2-21-55
29-35-2 1-28-54
29-35-7 2-24-55
*29-36-7 3- 3-55
*29-36-9 2-23-55
*29-36-14 2-14-55
*29-36-18 2-14-55
29-37-9 2-14-55
29-40-8 1-29-54
29-42-3 3- 7-55
30-25-1 3- 4-55
30-27-6 3- 4-55
30-28-2 2-14-55
30-30-1 1-28-54
*20-37-2 2-14-575
20-37-6 3- 3-55
*20-37-7 3- 3-55
30-27-8 1-28-54
*W0-28-1 3- 3-55
*30-28-5 3- 3-55
30-28-7 3- 3-55
30-38-9 1-21-54
*30-39-4 3- 3-55
30-39-5 7-18-51
30-41-1 2-16-55
31-24-1 3- 4-55
31-o0--1 1-27-54
*31-30-3 3-25-55


Calcium
(Ca)


40
110
191
222
108
132
86 1
82
204
147
260
94
124
126
128
113
214
118
197
77
106
160
172
108
204
214
74
134
74


Mag-
nesium
(Mg)

9.8
21
88
101
17
22
9.8
26
99
89
149
46
65
61
50
9.2
102
26
106
31
51
63
104
34
99
107
36
52
61


Hardness as


Sodium CaCOs conduct-
and po- Bicar- Sulfate Chloride' Di.- i: ance Temper--
i tassium bonate (SO) (Cl) solved (mi- ature pH
(Na +K) (HC03) solids Noncar- cromhoes (cF)
Total bonate at 25C)
31 48 102 44 280 140 101 431 8.1
29 362 54 50 508 361 65 787' 75 7.3
........ 164 668 52 1.250 840 ........ 1.500 78 7.3
21 161 755 69 1.380 970 838 1,610 79.3 7.6
.0 372 8 18 400 340 34 606 76 7.3
39 426 6 106 620 420 71 1.010 ........ 7.4
31 292 12 50 392 255 16 615 76 7.9
S32 323 35 56 446 312 48 700 76 7.9
I 61 169 665 155 1.350 916 778 1,740 79.5 7.3
....... 210 255 598 1,580 678 ......... 2.550 79 7.4
S394 184 700 878 2.630 1,260 1.110 3.820 79.8 7.4
6.4 187 245 21 578 424 271 780 81.5 7.6
10 180 400 25 776 577 430 994 82 7.5
.0 172 368 26 802 566 425 1.040 81.5 7.5
........ 174 390 23 ........ 524..... 995 77 7.5
17 351 12 41 410 320 33 637 76.5 7.3
43 154 690 144 1.450 954 828 1,750 78 7.3
8.3 270 116 55 516 402 181 781 76.5 7.7
........ 180 645 295 1.660 930 ........ 2,180 79 7.4
45 241 100 82 550 320 123 768 ........ 7.9
20 202 259 58 706 474 309 957 77.3 7.4
33 210 355 134 1,080 658 485 1,380 75 7.6
........ 182 542 208 1,410 780 ........ 1.810 ........ 7.3
46 248 175 89 662 410 207 911 76.2 7.4
218 186 542 472 1,660 916 769 2.530........ 8.2
229 182 540 540 1,910 974 825 2.830 79.5 7.3
15 196 170 20 438 332 172 650 79 7.5
........ 176 432 24 862 546 ........ 1.040 77 7.5
75 390 165 76 696 436 117 090 ........ 7.3


0


Specific




Table 5 (continued)

Hardness as Specific
Sodium CaCO conduct-
Date Calcium Mag- and po- Bicar- Sulfate Chloride Dis- ance Temper-
Well No. of col- (Ca) nesium tassium bonate (SO4) (Cl) solved (mi- ature pH
election (Mg) (Na-+K) (HCO3) solids Noncar- cromhos (CF)
Total bonate at 250C)


31-31-2
*31-32-2
*31-32-3
31-32-4
31-32-8
*31-34-1
31-34-10
31-34-13
31-37-3
31-37-6
31-37-10
*31-38-4
31-39-2
*31-39-3
*31-43-2
31-43-2
32-25-1
32-27-2
32-27-3
32-29-2
32-32-1
32-32-7
32-33-2
32-33-4
*32-33-6
32-34-6
33-23-1
*33-25-1
33-31-1


1-27-54
3-25-55
3-25-55
3-25-55
2- 8-55
3-25-55
1-21-54
2-4-55
1-29-54
1-21-54
2- 7-55
2-18-55
2-18-55
2-18-55
11-20-50
1-20-54
2-15-55
2-15-55
2-15-55
1-27-54
2- 7-55
2- 8-55
2- 7-55
2- 4-55
3-25-55
2- 4-55
2- 8-55
3-25-55
2- 4-55


137
178
58
163
150
57
193
236
227
187
~2
104
286
118
1,260
216
78
82
94
103
153
172
281
169
179
173
75
44
136


53
80
78
67
66
34
117
98
97
113
99
56
152
46
1, 590
93
39
48
48.
47
76
69
109
73
74
81
32
23
60


58
49
28
42
20
i133

1 i67
S35
628
25
13.100

3.2
1.4
54.
51
105
33
47
66
6.4
11
23


170
365
259
165
176
331
162
172
172
188
162
220
188
2 2
201
194
188
188
200
178
124
160
156
156
193
120
180
262
192


448
490
278
542
535
19
608
790
722
580
725
240
675
199
1.710
4V0
178
215
232
342
6F0
570
750
575
580
660
153
5 4
420


23
64
50
31
26
24
92
225
282
232
328
96
1,310
100
25.500
440
28
22
21
23
38
70
332
48
65
87
18
6
30


860
1. 120
712
1.010
914
352
1,260
1.670
1.770
1.510
1,820
750
3.560
680
43.500
1.570
454
492
550
752
1.100
1.090
1.870
1.140
1.140
1.270
444
254
856


556
773
465
682
646
282
802
992
966
858
986
490
1.340
484
9,800
924
355
402
432
450
694
712
1.150
722
751
764
318
2041
586


474
253
497
502





310
1186



294
9,690

248
2851



8594
593
666
171
204
428


1.050
1,510
1.030
1.250
1,160
580
1,510
2,120
2.240
1.950
2,390
1,040
5,260
963
53,600
2.320
671
725
784
904
1,300
1.350
2.400
1.340
1.430
1.500
636
418
1. 100


77

79.8
78


78
77
80
75
81.5
75.5
78
81.4
79
80
77
79
79
84
80

82
81


7.4
7.2
7.4
7.2
7.7
7.3
7.5
7.5
7.3
7.4
7.5
7.4
7.5
7.3
7.6
7.4
7.4
7.7
8.5
7.5
7.9
7.4
7.5
7.9
7.3
8.0
7.8
7.3
7.9


- -









Table 5 (continued)


Sodium
Date Calcium Mag- and po- Bicar- Sulfate Chloride!
of col- (Ca) nesium tassium ; bonate (SO4) (Cl)
election i (Mg) (Na+K)! (HCO,)

2- 4-55 195 78 105 168 580 208
1-21-54 176 107 ........ 172 530 202
2- 8-55 79 35 17 208 176 18
3- 2-55 80 41 0.9 192 178 19
2-15-55 88 45 5 188 220 23
2- 4-55 133 55 44 172 460 24
2- 4-55 114 65 69 120 505 56
2- 4-55 195 82 167 180 595 297
1-21-54 179 75 .. 168 535 175
2- 8-55 199 88 143 160 590 301
2- 8-55 136 57 37 172 425 50
2- 7-55 148 62 66 172 445 117
1-28-54 153 64 ........ 174 428 118
2- 8-55 171 72 111 178 510 204
2- 7-55 116 52 39 178 355 52
3- 9-55 106 58 34 188 310 72
1-27-54 69 13 ........ 270 40 28
2- 4-55 123 50 31 176 360 44
1-22-54 122 47 ........ 190 320 35
2- 4-55 159 69 62 180 505 100
2- 4-55 129 57 48 188 420 50
1-22-54 111 50 ........ 193 335 31


Hardness as
CaCO,


Well No.


33-33-8
33-35-4
34-23-2
34-25-3
34-29-1
34-31-2
34-32-3
34-33-7
34-34-2
34-35-2
35-31-2
35-32-11
35-33-6
35-34-5
36-31-1
36-32-2
37-29-3
37-31-3
37-32-10
38-32-5
38-32-9
38-33-5


Dis-
solved
solids
Total
1,390 807
1,280 770
510 341
454 368
570 404
792 558
952 552
1,530 824
1,280 760
1,560 858
852 574
1,040 624
1,040 648
1,330 722
748 504
788 503
388 228
738 512
736 500
1,030 680
820 556
754 482


Specific
conduct-,
ance Temper-
(mi- ature
cromhos (F)
at 25C)
1,810 80
1,770 77
692 80
687 79
813 80.1
1,040 77
1,150 79
2,070 81
1,670 78
2,110 79
1,120 78
1,360 79
1,400 77
1,740 79
1,020 79
1,070 78
556 76
1,010 80
976 77
1,340 81
1,070 78
950 76


Analysis of water from the Hawthorn or a younger formation.
1 Contains silica (SiO2), 21 ppm; iron (Fe) in solution, 0.00 ppm; total iron, 0.59 ppm; fluoride (F), 1.9 ppm; nitrate (NO3),
0.4 ppm; color, 5.
2 Contains silica (SiO2), 29 ppm; iron (Fe) in solution, 0.00 ppm; total iron, 0.07 ppm; fluoride (F), 0.9 ppm; nitrate (NOQ),
2.9 ppm; color, 12.
'Contains silica (Si02), 8.6 ppm; iron (Fe), in solution, 0.16 ppm; total iron, 5.0 ppm; fluoride (F), 0.2 ppm; nitrate (NO3),
22 ppm; color, 40.


Noncar-
bonate
670
170
210
250
417
454
676
728
433
484
576
358
349
368
542
402
. .. .. ...


pH


0


CA


7.4
7.3
8.0
7.7
7.3
7.6
8.1
7.3
7.3
7.6
7.6
7.6
7.5
7.6
7.6
7.5
7.7
7.5
7.6
7.7
7.7
7.7




Table 6. Water-Level Measurements
(All measurements in feet with reference to measuring point)

Water Water Water Water
Well No. Date level Date level Date level Date level
23-38-1............... 5-16-53 11.0 10-13-53 11.2 7- 1-54 12.9 3- 7-55 8.5
6- 3-53 9.5 12-11-53 11.0 8-16-54 13.2 7-21-55 11.6
7-23-53 10.2 3- 4-54 11.2 9-16-54 12.2 10-27-55 12.1
9-16-53 11.5 5-17-54 12.5 1-31-55 8.5 12-15-55 10.5
9-16-53 11.3 ............ .................................... ............ ............
23-38-2............... 3-16-54 14.0 8-21-51 15.2 7-29-52 13.4 2- 4-53 11.5
4-16-51 12.6 4-11-52 12.0 10-29-52 15.0 3-31-53 11.9
6- 6-51 12.6 5-25-52 10.8 12-15-52 11.8 4-30-53 11.0
25-31-7............... 10-27-52 5.2 7-22-53 3.46 12-22-54 4.2 6- 6-55 1.75
12-15-52 2.95 9-16-53 5.2 1-31-55 2.2 7-21-55 3.2
2-11-52 4.10 10-15-53 5.3 3- 9-55 0.35 9-15-55 4.2
3-31-53 0.47 12-18-53 4.8 4- 6-55 1.4 10-27-55 1.1
5-16-53 0.9 9-16-54 4.9 5- 9-55 2.2 12-13-55 1.4
6- 2-53 0.8 ............ ........................ ............ ............ ............
25-40-3B............... 3-16-51 14.0 7-29-52 14.2 6- 3-53 13.9 3- 4-54 14.0
4-16-51 15.5 10-29-52 14.7 7-23-53 14.3 5-17-54 14.0
6- 6-51 15.1 12-15-52 15.3 9-16-53 14.5 7- 1-54 15.2
5-21-51 16.1 2- 4-53 14.8 10-13-53 15.2 8-16-54 16.1
4-11-52 14.0 3-31-53 14.2 12-11-53 15.0 9-16-54 15.0
6-25-52 13.8 5-16-53 13.6 ........................ ............ ............
26-30-5............... 3- 1-54 9.0 11- 8-54 8.0 4- 6-55 8.3 9-15-55 10.1
6-30-54 10.2 12-22-54 10.0 5-10-55 2.35 10-27-55 6.7
9-17-54 11.1 1-31-55 6.5 6- 6-55 3.2 12-13-55 7.2
27-39-9............... 11-13-52 1.85 3-30-53 3.65 7-22-53 3.55 12-18-53 5.3
2-12-53 6.5 5-15-53 1.55 10-13-53 3.2 ......................


0

0








0
o0
00a









Table 6 (continued)


Well No.


27-41-2 ..............


28-37-6 ...............


Date


Water
level


2-18-51 7.0
3-16-51 7.5
4-17-51 7.8
6- 8-51 8.0
7-22-51 8.9
10- 2-51 8.2
5- 4-52 7.3
6-21-52 7.1

12-11-52 3.65
2-12-53 2.57


Date


7-30-52
9-27-52
11- 8-52
12-29-52
2- 3-53
3-20-53
5-15-53
6- 3-53

4- 7-53
5-15-53


Water
level


7.0
8.1
8.2
8.3
8.1
7.0
7.1
8.3

- 4.83
- 5.68


i Water
Date I level
_ ________i____


7-23-53
9-17-53
10-13-53
12-17-53
6- 7-54
8-18-54
9-15-54
11- 9-54

6- 3-53
7-22-53


7.9
8.5
7.8
7.4
9.0
9.0
8.8
7.5

- 4.68
- 2.25


Date

12-23-54
1-31-55
3- 7-55
4- 4--55
6- 7-55
7-22-55
9-13-55
12-13-55

9-15-53
12- 9-53


Water
level

8.0
7.8
7.4
7.6
6.5
7.2
7.5
7.6

- 1.58
- 1.22


29-26-1............... 2-22-51 1.72 9-19-51 1.87 2- 4-53 0.44 10-15-53 2.65
3-16-51 1.80 7-24-52 .90 4- 1-53 4.20 12-15-53 2.50
4-11-51 0.67 10-11-52 1.88 5-16-53 5.49 3- 1-54 0.1
6- 6-51 3.37 11- 7-52 .74 7-22-53 1.09 9-21-54 2.9
8-22-51 2.69 12-29-52 1.84 9-17-53 2.75 6- 7-55 4.5

29-34-1............... 6-27-51 0.27 12-29-52 .58 7-23-53 1.02 9-16-54 2.40
7-29-52 1.23 2-11-53 1.20 9-17-53 2.49 9-28-54 2.75
11- 8-52 .70 5-30-53 2.63 12-15-53 1.73

29-36-3............... 11-13-52 4.5 7-22-53 3.67 8-18-54 3.0 6- 6-55 5.70
12-22-52 5.6 9-15-53 3.01 9-16-54 2.5 7-21-55 3.17
2-11-53 3.9 10-13-53 2.95 11- 9-54 4.0 9-15-55 3.04
3-31-53 6.9 12-15-53 3.07 12-23-54 3.4 10-27-55 3.98
5-15-53 -7.6 3- 2-54 8.2 1-31-55 3.8 12-13-55 4.05
6- 2-53 6.3 4-27-54 5.1 4- 4-55 4.2

30-39-19............... 6- 7-54 5.7 11- 9-54 8.5 2- 2-55 5.3 4- 4-55 6.5
8-18-54 5.1 12-23-54 -5.7 3- 7-55 9.3 5-13-55 9.5
9-15-54 5 .1 ............ ............ .. ..... ............ ............ ............
,, + "*


-1 1 1


Table 6 (continued)
..... .


,i


1




Table 6 (continued)

Water Water Water Water
Well No. Date level Date level Date level Date level
31-38-4............... 3-16-51 5.8 10- 2-51 5.6 3-20-53 5.6 8-18-54 7.5
6- 8-51 5.1 9-27-52 8.3 5-15-53 3.2 ........................
8- 9-51 7.1 12-11-52 5.6 9-15-53 8.5 ........................
9-19-51 8.3 2-11-53 8.3 12-16-53 8.8 ............ ............
32-29-3 ............... 6-22-52 2.05 5-16-53 3.90 10-15-53 5.0 6-28-54 5.0
7-29-52 3.20 7-21-53 3.57 12-10-53 5.05 8-23-54 5.2
2-11-53 3.6 9-17-53 5.09 2-25-54 0.9 9-17-54 4.6
4- 1-53 1.77 ............ ............ .... ................ ........... ............
32-30-1............... 9-20-54 10.05 2- 2-55 13.5 10-26-55 14.45 ........................
12-22-54 11.9 5- 9-55 18.9 12-15-55 13.37 ............ ............
35-26-1............... 9-20-54 11.5 4- 6-55 15.3 5-31-55 17.95 12-15-55 ............
3- 9-55 16.8 5- 9-55 20.6 10-26-55 14.80 ........................
35-33-6 ............... 2- 7-51 8.4 12-28-51 10.4 10-:0-52 9.8 7-21-53 9.8
4-16-51 10.8 4-10-52 7.0 12-29-52 7.5 9-14-53 10.7
6- 6-51 5.5 5- 4-52 4.34 2-10-53 10.5 10-14-53 10.1
8-23-51 11.9 7-29-52 12.0 4- 1-53 8-.0 12-17-53 9.6
9-26-51 11.5 9-15-52 11.2 5-15-53 4.9 2- 2-55 8.4
10- 2-51 11.3 10-11-52 10.2 6- 2-53 6.1 ............ ...........
36-29-2............... 12- 7-52 7.5 3-10-55 10.60 10-26-55 8.07 ........................
9-22-54 2.7 5-31-55 8.10 12-15-55 5.99 ........................
36-32-2 ............... 3-20-51 13.1 7-29-52 13.0 5-15-53 6.7 f 9-14-54 13.6
4-16-51 14.2 9-15-52 14.3 6- 2-53 8.0 9-28-54 15.5
6- 6-51 11.5 10-11-52 14.1 7-21-53 11.4 3- 9-55 9.0
8-15-51 14.1 10-20-52 12.1 9-14-53 14.1 5-31-55 11.6
5- 4-52 7.6 2-10-53 3.2 10-15-53 13.6...
6-26-52 11.3 4- 2-53 9.0 12-17-53 13.6 ........ .. .... ..










Table 6 (continued)


Water Water Water Water
Well No. Date level Date level Date level Date level

37-24-2............... 4-20-52 1.83 4- 1-53 -4.10 6-28-54 0.5 4-19-55 2.40
6-22-52 2.26 5-16-53 6.44 8-23-54 .7 5- 9-55 8.00
7-24-521.00 7-22-53 0.38 9-30-54 1.35 5-31-55 5.60
9-16-52 0.75 8-19-53 0.2 11-11-54 1.75 10-26-55 2.57
10-11-52 .25 9-17-53 1.05 12-21-54 .9 12-15-55 -3.64
12-11-52 1.79 12-15-53 1.20 2- 1-55 2.9 ........................
2-11-53.64 2-25-54 2.9 3-9-55 -5.15 ........................

38-32-9 ............... 3-20-51 1.2 10-11-52 14.1 3-2-54 14.7 2- 1-55 12.9
4-16-51 14.7 2-10-53 12.2 6-29-54 16.2 3- 9-55 11.7
6- 8-51 12.1 4-2-53 8.2 8-17-54 14.7 4- 4-55 13.9
8-18-51 13.5 5-15-53 9.5 9-14-54 12.6 5-13-55 9.9
9-25-51 7.9 6- 1-53 9.4 9-28-54 15.4 5-31-55 13.0
5- 4-52 8.0 7-21-53 15.3 11- 5-54 13.5 9-15-55 12.2
7-29-52 11.5 9-14-53 14.9 12-22-54 14.0 12-14-55 12.5
9-15-52 9.5 12-17-53 11.2 ............ ............ ........................
I I I


0



Lu'
0

0

C,,

Lu'
84






REPORT OF INVESTIGATIONS No. 18


TABLE 7. Logs of Selected Wells in Manatee County
Well 17-11-1
(Florida Geological Survey No. W-2595)
Del
Lithology Lai
Pleistocene and Pliocene:
Sand, clear, fine, quartz --.......------- ..--------......................---.......-...
Sand, dark brown, fine, with some coarse grains; contains carbonaceous
and limonitic material ("hardpan") ..----- ...------...-..-........ ..--------..
Sand, tan, fine ............. ..........----------------... -----.. -.. --..---........... ...------------...
Sand, brown, very fine; a few heavy mineral grains and some linmonite
Sand, tan, less stained than above, fine to medium ......------....---..----....... ...
Sand, darker tan than above, medium, with some fine and a few large
frosted pebbles; some sand is frosted and some is polished ......... .-.-
Sand, dark gray-brown, fine to medium; dark mineral grains, some
larger polished quartz grains ..................._ .................... ...................-----
Sand, dark tan, fine to medium,, with some rounded, frosted, and
polished pebbles; a few phosphate minerals; fragments of brown
sandstone .......-....----.......-----....--..........--...------.......--------.............................-------..............
Sand, lighter tan than above, fine to medium, with frosted and polished
pebbles of quartz; many dark gray pebbles of phosphate minerals ......
Sand, as above, but lighter in color and finer .----....... ...---- -----....-
Sand, as above, but dark gray-tan in color ....-....-.....................
Sand, as above, with some calcareous cement .. ..-- ---.............
Sand, gray, medium to coarse; much black phosphate minerals, fine to
pebble size; calcareous clay ................-----__......-..-- ....----
Sand and gravel of quartz and phosphate minerals; gray fairly hard,
sandy, silty limestone; shark tooth ..............---------.........--- --.. -----.
Hawthorn formation:
Sand and gravel of quartz and phosphate minerals; gray-green, silty,
calcareous, slightly sandy clay, with fine black and gray phosphate
minerals ............................-- -------------------------------.------------------..
As above, with fragments of gray-tan to dark gray limestone .....-----
Clay, greenish-gray and green, calcareous, sandy, phosphatic ......
Sand and gravel of quartz and phosphate minerals; dark gray, hard,
sandy limestone -------..-...-.........-- ---................- ---------...................... ...
Limestone, light to dark gray, hard, sandy; phosphate and quartz
pebbles; mollusk fragments -----....--.....----....--...........--...---....-------......-----......
Clay, light gray, chalky, sandy; limestone as above; quartz and
phosphate pebbles ..-........----------------. ------------- .. --------------
Clay, gray, silty, sandy, calcareous; fine-grained phosphate minerals;
impure limestone .---------.........................---..-. -----------------------.--
Limestone, gray to tan, hard, sandy, porous in part, crystalline in part,
fossiliferous; chert .........................................--- ....-....-....-.......----...-.......-----
Limestone, gray-white, fairly hard, crystalline in part, fossiliferous,
slightly sandy ....--- .--------- .......................---------- ...........----.------.......--
Limestone, as above; gray, calcareous, chalky, sandy clay; chert; sand;
phosphate minerals ...--......-------...--....................---...........................--..........------
Clay, as above; gray and tan, hard, dense limestone .............-.........
Clay, as above; gray-white, hard, sandy limestone, crystalline in part;
chert; phosphate minerals -....................................................................
Clay, dark gray-green, calcareous, silty, sandy; phosphate minerals;
limestone, as above .............................................---....-...---..--......--------..............
Clay, gray-white, chalky, sandy, with phosphate grains and pebbles;
white to tan, hard, sandy limestone; some chert .............................


pth Below
nd Surface
(feet)
0-8

8-10
10-15
15-20
20-25

25-40

40-50


50-00

60-65
65-70
70-75
75-80

80-90

90-95



95-105
105-125
125-129

129-135

135-144

144-155

155-170

170-180

180-196,

196-213
218-218

218-230

230-235


235-260







FLORIDA GEOLOGICAL SURVEY


Clay, gray, calcareous, sandy, with phosphate; tan and gray, hard,
sandy limestone; phosphate minerals and chert ..........------.--..................--------. 260-291
Limestone, white to tan, soft, fairly pure, fine, granular, fossiliferous;
chert and phosphate pebbles ....-------...--...-.....--.......................---------...... 291-300
Clay, white, chalky; tan, fairly soft, fossiliferous limestone, crystalline
in part; some chert ..- --- ...------.........----................----.--------... 300-306
Clay, dark green, silty, sandy, calcareous; white, gray, and tan, hard,
dense limestone, crystalline in part; chert ...-..........-...---........-------.....---...---. 306-317
Clay, reddish-tan, calcareous; tan and gray, hard, dense limestone, some
white, sandy; much dark brown chert -----.--.............------------....-. 8317-323
Clay, white, chalky; tan, hard, finely crystalline dolomitic, fossiliferous
limestone; chert; fine sand; phosphate minerals ....-------...---......---. 323-340
Clay, as above, with brown and gray chert .-------.. ..------..--.. ------ 840-345
Clay, gray and white, chalky, phosphatic; tan, finely crystalline, hard
limestone; some chert -------- ---..------....-.....-... 845-360
Clay, gray, sandy, chalky, phosphatic; white to tan, soft, sandy
limestone, porous in part, hard, dense, silicified, dolomitic in part,
fossiliferous in part ------------- -------- ------------------ 360-365
Clay, as above; white and gray, hard limestone, very sandy in part .. 8365-377
Clay andI limestone, as above; many shell fragments, ostracods, and
Foramlinif(era -............------------------------------ ----..---------.... 77-883
'l'anpa formation:
L[imtestone, white and gray, fragmental, fossiliferous .---- ....---.--..... 383-390
Limestone, white to tan, soft, sandy in part, porous; fine sand; shell
fragments, Foraminifera ---..---------------------.------------- 390-396
Limestone, gray, white and tan, hard, sandy, fossiliferous; contains
crystalline calcite, phosphate minerals, sand and chalcedony ..--------..... 896-400
Limlwstone, gray, white to tan, hard, very sandy, dolomitic in part,
porous in part; some chert; fossiliferous, mollusks, echinoid spines,
Sorits sp., and other Foraminifera .----.. ....--- .....------ .... ------ 400-443
LimestoIne, creamy white, soft, chalky, containing many Bryozoa, also
gray and tan, hard, sandy, fossiliferous .--..----.--.-----------... ..-----.. 448-456
Limestone, white, soft, chalky, sandy, fossiliferous; phosphate grains 456-464
Limestone, as above, with some dark gray, hard, sandy .---....---------........ 464-471
Limestone, liglit to dark gray, tan, hard, dense, very sandy, crystalline
and dolomitic in part; fossiliferous; some phosphate and chert ....-- 471-497
Lidmestonle, white, fairly soft, chalky, very sandy, fossiliferous; some
black phosplate grains; molds and casts of mollusks---- .-.....--.--..----.... 497-512
Clay, gray, green, waxy; fine sand; phosphate minerals; limestone, gray,
hard, dense, with fragments and pebbles of sandy limestone ..------.. 512-517
Limestone, white and tan, chalky, sandy, granular in part; chert and
chalcedony; mollusk molds and casts, and ostracods .......-------........------. 517-539
Clay, gray to tan, waxy, shaly, slightly sandy, calcareous; much very
fine phosphate, also some white, chalky, very sandy; a few limestone
fragments -- ..........-------------------- 539-544
Limestone, white, soft, chalky, very sandy; phosphate minerals; also
some tan, hard, dense limestone -...- -.----- ....................-------------------.-------- 544-578
Liimestone, as above; some chert .......---.-- .... .---.........------.. 578-582
Limestone, as above, fossiliferous .--- ..........-- -------------...............----------. 582-586
Limestone, as above, also tan and brown, hard, dense, less sandy,
fossiliferous; very little phosphate ... ....----...........-----------... 586-596
Limestone, gray, tan, and brown, hard, dense, sandy in part, porous in
part, fossiliferous; contains crystalline calcite .--.---...........-..-..--..-.........--------------.596-608
Limestone, as above, but more granular; Archaias floridanus present ..-- 608-612
No sample ---.. .. ----------------..-......... --- --....------..........................-.......... 612-624


90







REPORT OF INVESTIGATIONS No. 18


Suwannee limestone:
Limestone, creamy white and tan, fairly hard, granular, porous in part;
poorly preserved fossils, Rotalia mexicana, and other Foraminifera .... 624-631
Limestone, white to tan, soft, pure, granular, porous, fossiliferous;
abundant echinoid spines and plates, Rotalia mexicana, and other
Foraminifera --...----................---......--------------------..........................---.-----........-................-----.... 631-720
Limestone, as above, but darker tan and more crystalline; fewer
F oraminifera --........-.....................--..---....................--...........--------------------------.............---.. 720-767
Limestone, as above, but less granular ..------..-----..--........-----.........-----..............--...... 767-773
Ocala group:
Limestone, gray-tan, "dirty" appearing, fairly soft, somewhat granular,
fossiliferous ..............................................................----........................... 773-783
Limestone, gray, tan, fairly hard to soft, granular to fragmental,
crystalline in part, fossiliferous; many Foraminifera, including
Gyipsina globula ................................-------...-----.......--.-------------...............----. 783-805
Limestone, as above, with Lepidocyclina floridensis, L. ocalana, Iletero-
stegina ocalana, Operculinoides sp. ..------.........--..-.--.--....................------...---....---..... 805-831
Limestone, gray to tan; foraminiferal coquina with a fine granular
chalky matrix, Nummulites sp., Gypsina globula, Lepidocyclina
ocalana, Operculinoides floridensis, Heterostegina ocalana .--..............-------- 831-930
Limestone, as above; gray-tan, sticky, calcareous clay ...........-- ............. 930-937
Limestone, as above, and brown, hard, crystalline dolomite ...--...----- 937-955
Limestone, dark brown, saccharoidal, dolomitic; some fragments are
white, fairly soft ..........-....-....-----..-..-..--..--.........................---------.------....-----...----. 955-974
Limestone, as above, but porous ....--....---.......-------------..... ----..--... 974-981
Limestone, as above, but lighter in color ...--...---.. -------..---------... 981-987
Limestone, as above, but gray-tan in color ------..-.. --.... ---- .--.. ...-..---..-. 987-1,051
Limestone, dark brown, saccharoidal, dolomitic; some fragments are
white and gray -..-...-----------.. -----------........ ------...-------...... 1,051-1,068
Limestone, as above, also tan, fairly hard, dense, some granular, porous
in part, fossiliferous; contains mollusks, echinoids, ostracods,
Foraminifera, Gypsina globula, Nummulites sp., and others .......---... 1,063-1,089
Limestone, gray and tan, hard, dense, dolomitic in part, crystalline in
part, has chalky matrix; mollusks, echinoids, Foraminifera .-------- 1,089-1,097
Avon Park limestone:
Limestone, tan, fairly soft, granular, chalky, crystalline calcite,
echinoids, ostracods, Dictyoconus cooked, and other Foraminifera .-.1,097-1,112
Limestone, as above, also porous, foraminiferal; abundant Dictyoconus
cooker, ostracods, echinoids ........ .......------.------........ ...------.------..-.....-- 1,112-1,136
Limestone, creamy white and tan, soft, granular with a chalky matrix,
foraminiferal, crystalline in part; Dictyoconus cooked, Lituonella
floridanus, Valvulina sp., and other Foraminifera .......-------------.... ... 1,136-1,151
Limestone, white and tan, soft, chalky, granular, porous, foraminiferal;
Dictyoconus cooked, Spirolina coryensis, Valvulina sp., and others ..-1,151-1,246
Limestone, as above, but with fewer fossils; also brown hard crystalline
dolomite ---------...-......... ............... .........-------............------ ------- ......----..... 1,246-1,253
Limestone, creamy white to gray-white and tan, hard, dense to
granular, chalky, fossiliferous; some brown crystalline dolomite;
Dictyoconus cooked, and others ..--.--...........-........---.......-----.-------..........--..... 1,253-1,275
Limestone, as above, fossils fewer and poorly preserved ..-- ---......----...1,275-1,301
Limestone, as above, but more fossiliferous ..........-.....-..-..--....--.------............ 1,301-1,330
Limestone, dark tan and gray, hard, dense, nodular, porous in part,
fossiliferous; Dictyoconus cooked, and others --..........-...----.........--.......----..-....--. 1,8830-1,376
Limestone, as above; dolomite, dark brown, crystalline, porous -----.......... 1,376-1,418







FLORIDA GEOLOGICAL SURVEY


Well 23-30-1
(Florida Geological Survey No. W-257)
Depth Below
Land Surface
Lithology (feet)
No sample .....------------......---.........--...................................-----------..........----------..........--...-....-.......--. 0-25
Hawthorn formation:
Clay, dark gray-green, shaly, slightly sandy, phosphatic, calcareous;
small amount of white soft limestone, and a few shell fragments .... 25-35
Limestone, white, soft and chalky to hard; fine black phosphate min-
erals; some fine sand .............----------------------------...................................................... 35-40
Clay, dark gray-green, silty, slightly sandy, calcareous; some phosphate
minerals ----------...-.--------. ----. ------------------.......... 40-50
Clay, gray-white, chalky, with fine phosphate minerals; white hard
dolomitic limestone; some chert and fine sand --....------------.............-...-.....--... 50-60
No sample ------------------------... ........ ...........------.....---------...----- 60-90
Clay, gray-white, chalky, with fine phosphate minerals; limestone,
white, hard, dolomitic; some chert and fine sand ..----.....---..................--------- 90-120
Clay, gray, very sandy, calcareous, silty; much fine dark phosphate
minerals and some white limestone --------. ...........-----------------........... 120-175
Clay, white, chalky, sandy; phosphate minerals; some limestone and
chert; fragments of mollusks and echinoids ......------------------ 175-200
No samples ... .. ..... ..----------- ....... ..---------- --------------........----- 200-230
Clay, dark gray, calcareous, silty; fine to coarse sand; gray, tan, and
black phosphate minerals -------------..-. ------.---------. 230-240
Clay, gray, silty, sandy, calcareous; phosphate minerals and some white
soft limestone; some chert -.....--------...----------------......................--.. 240-250
Clay, gray-white, chalky, slightly sandy; some fine phosphate minerals;
some gray-green waxy clay; some soft white limestone .-...--...........--------... 250-280
Clay, as above; white, soft, sandy limestone, containing some chert and
mollusk fragments. ..--------..-- ......-----------....- --------... ----..............-. 280-290
Clay, as above, with some limestone, chert, and sand ..-....-..--..--......---......---. 290-390
Tampa formation:
Clay, as above; limestone, white, soft, finely crystalline, dolomitic;
chert; oolitic chalcedony------- --- -----------.....-----... ----..... 890-400
Limestone, creamy white, very sandy, fairly soft; fragments of mollusks,
Bryozoa and echinolds; ostracods and Foraminifera --.....--------...--..-.. 400-420
Limestone, its above; Sorites sp .----....--------------------------- 420-440
Limestone, tan and brown, less sandy than above; abundant fossils .-- 440-470
Limestone, creamy white to tan, hard, porous in part, sandy in part,
fossiliferous, crystalline in part; Archalas floridanus, and Sorites sp... -470-500
Limestone, as above; also tan, hard, somewhat granular, porous,
fossiliferous -.--.... ---... ----...-....................................------------.............. 500-550
Limestone, gray-white to tan, fairly hard, porous, somewhat granular,
sandy, fossiliferous, Archaias floridanus, and other Foraminifera ....... -- 550-560
Suwannee limestone:
Limestone, gray to tan, granular, porous, crystalline in part, fossiliferous 560-580
Limestone, creamy white to tan, pure, soft, granular, very porous,
finely crystalline, fossiliferous; abundant miliolids and other Fora-
inifera ------- ...----- --- .... .....--------------------...........................--......---... 580-590
Limestone, as above, well preserved; Rotalia mexicana ..---..--.................----------.. 590-600
Limestone, white, soft, granular, porous, very fossiliferous --..-...-..---........... 600-6380
Limestone, cream to tan, soft, granular to dense, porous, fossiliferous 680-640
No sample -----------...-------------..............-------------......---..........----............... 640-650
Limestone, tan, hard, dense, fossiliferous ..---.--.-----------.....--........-........-..... 650-675.


92







REPORT OF INVESTIGATIONS No. 18


Well 26-22-1
(Florida Geological Survey No. W-3612)
Depth Below
Land Surface
Lithology (feet)
Pleistocene and Pliocene:
Sand, clay, impure limestone, quartz, and phosphate gravel ...------------ 0-10
Clay, greenish-gray, calcareous, silty, sandy; quartz and phosphate
gravel; gray, hard, sandy, impure limestone fragments; mollusk
fragments ..........-------------........................-......................----------.--------................---...-----.. 10-60
Hawthorn formation:
Limestone, gray-white, chalky, dolomitic, sandy in part; phosphate
grains and pebbles; gray, calcareous, sandy clay --..................------------ 60-120
Limestone, as above, with some chert .. ............-----------------.. .... -------.. 120-140
Limestone, gray-white, soft, chalky, sandy, to gray, hard, dense; clay,
greenish-gray, sandy, calcareous, phosphatic .-------- ....-----------. 140-150
Clay, gray to greenish-gray, chalky, sandy, phosphatic; white and gray,
soft, chalky to hard, dense limestone ----------------------- 150-160
Clay,' gray-white, chalky, sandy, phosphatic; sand; gray chert and some
impure limestone ..---........ ...----------------------------------. 160-210
Clay, as above; limestone, gray-white, hard, sandy; chert; phosphate
grains and pebbles; mollusk fragments ...---..-------------------. 210-220
Clay, as above; tan to dark gray, crystalline, sandy, phosphatic limestone 220-240
As above, with much sand and phosphate minerals --------------- 240-290
As above, with some chert ....-------------------------------. 290-300
Limestone, white to gray, hard, sandy in part, fossiliferous; green
waxy, silty, sandy, calcareous, phosphatic clay .-----------------. 00-330
Clay, gray, chalky, sandy, phosphatic; gray and tan, hard, very sandy
limestone, crystalline and dolomitic in part .......------------------- 33880-360
Tampa formation:
Limestone, tan, fairly hard, sandy, porous, crystalline in part, fossili-
ferous; small amount of phosphate minerals; mollusk casts and molds,
echinoid spines and Foraminifera, Archaias floridanus, and Sorites sp. 360-380
Limestone, as above, with some chert ... .....-----------------------. 880-390
Limestone, as above, but less porous ...... .....-------------------------.. 890-400
Limestone, light to dark tan and gray, hard, dense, sandy, crystalline in
part, fossiliferous ............-------------....------------------------.... 400-450
Limestone, gray-white, hard, dense, porous in part, slightly sandy, fos-
siliferous; Archaias floridanus .... ....-------- ...........--------------------..... 450-460
Limestone, gray and tan, hard, dense, porous (contains solution cavi-
ties), partly granular, sandy, fossiliferous; abundant miliolids,
Archaias floridanus .......... -----------------------------------.....460-480
Limestone, white to tan, fairly hard, sandy in part, porous; some frag-
ments are creamy white, soft, granular, porous, and fossiliferous;
Archaias floridanus, and Sorites sp .............-------------------------. 480-530
Suwannee limestone:
Limestone, creamy white, soft, granular, fossiliferous, crystalline in part;
Rotalia mexicana, and other Foraminifera------ ....-------------- 530-550
No sample ----......------.. .....-....---- ....... .....----------------------.. 550-556
Limestone, creamy white to tan, soft, granular, porous, fossiliferous,
crystalline in part; mollusk fragments, echinoid spines and plates,
Foraminifera, Rotalia mexicana ..------.....---...--.....--------------------- 556-610
Limestone, gray-tan, harder and more crystalline than above, granular
in part, porous, fossiliferous, mollusks, echinoids, Rotalia mexicana,
and other Foraminifera ...........................................................------------.......... 610-630


93







IF AI ,w1A CGIOLOCtCAI, SURVEY


Limestone, It s above, but more granular and softer ...--.-............ 680-660
Limestone, tan and brown, hard, crystalline and dolomitic, fossiliferous;
iIollusks, ehinoilds, Rotalla mexicana, and other Foraminifera -- 660-700
Limestone, tan, fairly hard, granular to chalky, crystalline in part,
fossiliferous, Hotalia mexicana, and other Foraminifera -..---.---- 700-720
Ocala group:
Limestone, tan, soft, fragmental, silty, chalky, crystalline in part,
foraminiferal, Gypsina globula, Nummulites sp., Lepldocyclina oca-
hla, IL. floridh'en.s, and others -.....--- ..-.--- ...--....--- 720-840
Limestone, coquina of foraminifers and other fossils in a chalky matrix;
Camerina, (Gypsina globula, Lepidocyclhia ocalnma, Opercullnoldes
floridecn.ds, lleterostegina ocalana, and others ...-----.. ---------840-960
iimnestone, brown, hard, dolomitic and crystalline, chalky matrix, not
very fossiliferous; a few Lepidoclyclna noted --------------. 900-990
Limestone, as above, more fossiliferous; Nummulities sp., Lepldo-
('riclina ocWahma, O(perculinoide's sp., and others ------ ------- 990-1,000
limeistone, white to brown, chalky, soft, crystalline, coquinoid; Forn-
minifera and other fossils ..........----------------------.. .... 1,000-1,020
Avoui Park limestone:
limestone, tan to brown, fairly soft, granular, crystalline in part,
dolomitic, chalky matrix, fossiliferous, echinoids, Dictiloconus cooked,
Splrolina corl-ensls .. .. ------. .- 1,020-1,000
Inimestone, as above but softer and more chalky --.- --.-------1,060-1,080
Limestone, cream and tan, soft, coquinoid, some crystalline and
dolomitie ... -.---. -----.- ... 1,080-1,110
Limestone, light to dark brown, hard, dolomitic, crystalline, linonitic
inll part; contains solution cavities; some lignite .-..------.------1,110-1,180
Limestone, as above, with fragments that are white, soft, fossiliferous,
and porous -.-..---------------.-- --.---------1,130-1,140
Limestone, as above; Coskinolina floridaia, Dlctiloconus cooked,
Spilroiuna ((or yen.si's, Valvulina sp., and other Foraminifera .---- -- 1,140-1,160
LhI stone, dark brown, hard, crystalline, dolomitic, porous .--.----- 1,160-1,170
Limestone, dark gray and brown, hard, dense, finely crystalline, dolo-
mitic, porous ili part, lignitic -.-------_----.... 1,170-1,190
No sample .. ..-..... ... 1,190-1,820
Limestone, dark brown, as above, to tan, very porous; no fossils noted -- 1,820-1,870
Limestone, as above, with some carbonaccous material ----------1,870-1,400
Limestone, ias above; fossils rare, poorly preserved -----.--------- 1,400-1,420
Limestone, tan, fairly soft, somewhat granular, porous, carbonaceous;
few poorly preserved fossils -- ----------------------------1,420-1,510
,imestolne, lan and brown, hard, crystalline in part, porous in part,
lilnonitic in part, carlbonl aceous ...... .. -.--- -------.... 1,510-1,540


94







REPORT OF INVESTIGATIONS No. 18 95

Well 29-83-1
(Florida Geological Survey No. W-75)
Depth Below
Land Surface
Lithology (feet)
Pleistocene and Pliocene:
No sample -------------------- -------.---.- -----------.... ..... 0-20
Sand, brown stained, fine to coarse, quartz; large rounded and frosted
quartz pebbles; some impure limestone fragments; carbonaceous
material ------ .-------------------....--.... ..--------- 20-21
Sand, white, quartz, fine; pebbles as above; brown shaly clay; bone
fragments -- ----.----------- .. .......-------------- 21-24
Limestone, white, hard, dolomitic, somewhat chalky; fine sand and
phosphate minerals .-------------------------------.............24-80
Limestone, white, hard, dolomitic, porous in part, phosphatice; chert;
mollusk casts and molds ----------.---.....--....... 30-388
Hawthorn formation:
Limestone, white, chalky, sandy in part; phosphate, fine sand to pebble
size --- ------------------- ----......... -- --------....... ......... 38-74
Clay, gray, calcareous, sandy; phosphate grains and pebbles; limestone,
gray, fairly hard, impure, sandy; chert ----.------------------- 74-78
Clay and limestone as above; phosphate gravel; much chert -- --- 78-80
Clay, gray, chalky, sandy, phosphatie; limestone, white, sandy, chalky,
phosphatic; chert --------- -------------------- ---------------- 80-96
Clay, light to dark gray, calcareous, sticky, sandy; impure limestone;
phosphate minerals and chert ----- ---- ---------------- 96-110
Clay, dark blue-gray, calcareous, sticky, phosphatic 110-126
No sample .--------------------------.......... 126-182
Clay, gray, calcareous, sticky, phosphatic; limestone and chert ------ 132-154
Clay, gray, calcareous, silty, sandy, phosphatic; some gray, sandy lime-
stone; a few mollusks ---.---...- ---------------------....... 154-185
Clay, white, chalky, sandy; phosphate grains and pebbles; white, hard,
sandy, phosphatic limestone; a few mollusk molds and casts ----.- 185-220
Limestone, gray, hard, silicifled, sandy in part, phosphatic .-----------..... 220-235
Clay, gray-white, calcareous, sandy, phosphatic; white fairly hard
limestone; sandy chert and chalcedony --.-------...-------------.. 235-250
Clay, as above; white, fairly hard, dense limestone; shell fragments .... 250-270
Clay, gray, calcareous, sandy; white and gray, hard, phosphatic, sandy
limestone; fine sand and pebbles; chalcedony ----------------.... 270-280
Hawthorn and Tampa formations undifferentiated:
Clay, as above; gray and tan, fairly hard, sandy, fossiliferous limestone;
chalcedony; Archaias, Sorites, and other Foraminifera ...........------------.... 280-300
Tampa formation:
Limestone, gray and tan, hard, dense, porous in part, sandy in part,
fossiliferous, phosphatic; Archaias floridanus and Sorites sp .-------- 300-340
Limestone, tan, slightly sandy, fairly hard, porous, fossiliferous; mol-
lusks and Foraminifera, Archaias floridanus and Sorites sp. -------340-370
Limestone, tan, fairly hard, sandy, porous, crystalline in part; chert;
mollusks, ostracods, Archalas floridanus, Sorites, sp., and other
Foraminifera ..... .----......................-------------.---...... .. ... ---------....-...--..... ... ---. 370-397
Limestone, gray and tan, hard, slightly sandy, dense, porous in part,
dolomitic in part, fossiliferous; some chert ..----..--....------------. 897-440
Suwannee limestone:
Limestone, creamy white and tan, soft, granular, porous, foraminiferal 440-450






FLORIDA GEOLOGICAL SURVEY


Limestone, creamy white, soft, chalky, granular, porous, fossiliferous 450-5831
Limestone, white and tan, soft, granular, fossiliferous; mollusks, abun-
dant echinoid spines and plates, Rotalia mexicana, and other
Foraminifera -- -- ..-...... -- -.-............. .- ....-- 535-558
imhnestone, gray and tan, soft, granular, porous; cchinoid fragments
abundant, few Foraninifera .- ..--- -..-. .......--........ 555-571
I'huestone, as above, with abundant well-preserved lIotalta mexicana,
and other Foraminifera .- .- ......-.....--.- ....-...... ..-. 575-600
lhiestone, creamy white, soft, granmular, porous, somewhat chalky,
foramui iferal .. .. ........... .. -. .......... ... 6000. 50
ilumestone, tan, soft, granular, fossiliferous, liotalla mexicana --------- 080-007
Litmestone, dark tan, granular, crystalline in part, fossiliferous; Dictyo-
Crou.s cooked, I{otalia mexicana, and other Foraminifera .- ... 667-6084
Dolomite, tan to dark brown, hard, finely crystalline, porous in part;
some limestone as above --- ...-- ..-.-.--. -------- 085-700
I, nestone, gray and tan, hard, dense, finely crystalline, dolomitic 700-71C
Dolomite, dark brown, hard, crystalline; tan, granular, porous, chalky
ltestone; abundant milliolids .-------------------------- 710-745
O(cila Grollp:
1itmestone, creamy white and tan, fragmental, granular, somewhat
chalky, very fossiliferous; mollusks, cchinoids, Bryozoa, Gypsina
globula, and other Foraminifera ...---------.----------745-800
ltimestone, white and tan, soft, granular; in part a foraminiferal coquina,
Nummulites sp., Lepidocyclina sp,, Ileterostegia ocalana, and
others .- .......... .. 800-922






R1EPrOR OF INVE1STIAT1ONs No, S8


Well 80-27-4
(Florida Geological Survey No, W-2817)
Depth Below
Land Surface
Lithology (feet)
No sample -------------------------------- 075
Hawthorn formation:
Clay, gray-white, calcareous, chalky, sandy; fine phosphate grains; lime-
stone, gray, tan, sandy in part, crystalline in part, porous in part,
phosphate; few fossil fragments --------.. 75-105
Clay, as above; sand, fine to medium; shells --------- 105-115
Clay, gray, chalky, sandy, and green shale; light gray, hard, sandy
limestone, porous in part; chert; phosphate minerals; fragments of
mollusk shells and casts ------- -------- 115-185
Clay, gray-white, gray and tan, sandy, calcareous, phosphatic; gray,
hard, sandy limestone ----------. -------....---- 185-145
Silt, greenish-gray, calcareous, very sandy; fine sand; fine black phos-
phate minerals; some gray-white limestone-- .... ---- 145-155
Clay, gray-tan, silty, very sandy, calcareous; fine phosphate; limestone,
gray, hard, with few mollusk molds and casts -------- 155-175
Clay, dark gray-green, very silty and sandy, some dark gray-brown,
waxy; small amount of lihnestone ----- ---------------- 175-105
As above, with some chert ---..------------------- 105-225
Clay, gray-white, chalky to greenish-gray, waxy, sandy; limestone,
gray, impure, sandy; mollusk molds and casts; phosphate minerals;
some chert .... --....--..---.--.----- 225-265
Clay, white, chalky, sandy; phosphate minerals; limestone fragments;
chert ...-----.----- ------------------------- 205-285
Limestone, light to dark gray, hard, sandy, dolomitic in part; thert;
a few mollusk fragments --------------------... .. 285-295
Limestone, as above; clay, gray, chalky, sandy, phosphatic--------- 295-315
Clay, as above; some dolomite; limestone and shell fragments --------- 15-325
Hawthorn and Tampa formations undifferentiated:
Clay, as above; white and gray sandy limestone, dolomitic in part;
mollusk and echinoid fragments -.--. ---------------------825-335
Tampa formation:
Limestone, white and gray, hard, sandy, porous, fossiliferous, dolomitic
in part; mollusks, echinolds, Archaias floridanus, Sorites sp., and
other Foraminifera ..-......-... ----- 33885-345
Limestone, tan, gray and brown, fairly hard, porous, sandy in part,
dolomitic and crystalline in part, fossiliferous; mollusks, Archaias
florikanus, Sorites sp., and other Foraminifera -..---- --------- 345-885
Limestone, light to dark gray and tan, hard, sandy, fossiliferous, dolo-
mitic and crystalline in part; Archaias floridanus and Sorites sp. 885-485
Limestone, white and tan, hard, sandy, fossiliferous, porous in part 485-465
Suwanneo limestone:
Limestone, light gray and tan, fairly soft, granular, porous, fossiliferous,
Rotalia mexicana and other Foraminifera ...................---------- --- 465-485
Limestone, tan, soft, granular, porous, fossiliferous, crystalline; calcite;
mollusks, echinoids, Rotalia mexicana, and other Foraminifera ....... 485-545
Limestone, tan to gray-tan, soft, granular, porous; abundant mollusks,
echinoids, Rotalia mexicana, and other Foraminifera .................... 545-605
Limestone, gray, tan and brown, granular, fossiliferous, as above, with
specimens of Dictyoconus cooked ...................... .....................-- .......... 605-625







FLORIDA GEOLOGICAL SURVEY


Well 35-26-1
(Florida Geological Survey No. W-2715)
Depth Below
Land Surface
Lithology (feet)
Pleistocenle and Pliocene:
Sand ......-- --.. .--- ---.. ------- ....... 0-15
Clay, yellow to brown, calcareous, fine to coarse sand and phosphate
grains ----... --... ----- ---- 15-21
I lawthorn formation:
Clay, gray, calcareous; phosphate minerals, sand and pebbles ---------- 21-61
Sand, quartz and phosphate, fine; some clay, as above ....----------- 61-62
Clay, gray-green, slightly calcareous, silty, slightly sandy, very fine,
phosphatic ...................................... 62-85
Clay, gray, calcareous, sandy; phosphate minerals and sand, fine -.... 85-100
(lay, as above; white and gray, hard, impure limestone, porous in part 100-140
Clay, light gray to dark greenish-gray, silty, phosphatic; very little sand 140-160
Clay, light to dark gray, calcareous, sandy, phosphatic; fragments of
gray limestone .--- --- ------------ 160-185
Clay, gray-white, chalky, silty, slightly sandy, phosphatic --------.. ---- 185-200
Clay, as above; gray and tan, hard, dense, sandy limestone ----------200-215
Clay and limestone, as above; many phosphate pebbles; gray chert;
mollusks and ostracods ..... .--.----- 215-250
Clay, as above; some limestone, as above; much quartz and phosphate
sand -. ------ ------------------ .-----------... 250-330
limestone, gray and brown, hard, crystalline, some white, soft, sandy,
fossiliferous; fragments of Archaias floridanus ---- ---------. 880-347
Tampa formation:
limestone, dark brown, hard, sandy, crystalline and dolomitic, porous
in part; chert; Archaias floridanus .... --.-.-.... ------------- 347-385
Limestone, tan, gray and brown, hard, crystalline, sandy, dolomitic,
porous; chert .- ...- -.... -..-..-..- ..- 885-400
lilWestone, gray and tan, soft, chalky to fairly hard, granular in part,
porous, fossiliferous; miliolids, Archalas floridanus, and other Fora-
m innifcra ...................... ... ... 400-450
Sliwannee limestone:
milestone, creamy white to tan, soft, granular, porous, some crystalline,
and fossiliferous; mollusks, echinoids, Rotalia mexicana, and other
lForaminifera .. --- -- -- -.. --------------------- 450-570
l,imestone, cream to tan, granular, crystalline in part, to gray hard,
dense; chert; Coskinolina floridaa, Dlictyoconus cooked, Rotalia
mrxicnnJa, and other Foraminifera ..--. ---...------------ 570-590







REPORT OF INVESTIGATIONS No. 18 99

Well 86-29-1
(Florida Geological Survey No. W-2393)
Depth Below
Land Surface
Lithology (feet)
No sample -.. ...........-- .... .. ............. .. .... .... (0-75
Hawthorn formation:
Clay, gray, sandy, calcareous; with phosphate grains and pebbles and a
few fragments gray impure limestone ... .... .. .......... 75-85
Clay, as above; gray-white, sandy, phosphatic limestone .. ... 85-100
Clay, as above; light to dark gray limestone, very sandy in part; fine to
coarse phosphate sand; few shell fragments .-------.. ........... 100-125
Clay, greenish-gray, calcareous, sandy; gray and black phosphate grains
and pebbles; gray, hard, impure, sandy limestone; a few poorly pre-
served Foraminifera ........-----...-... .. ....... 125-150
Clay, gray, sandy, calcareous, with fine to coarse phosphate sand;
gray and tan, fairly hard, impure, sandy limestone; few shell frag-
ments and poorly preserved Foraminifera .. ... ..-. 150-175
Clay, as above, with a few limestone fragments .....-.- ....- 175-200
Limestone, gray-white, fairly soft, chalky, sandy, with phosphate; few
mollusk fragments; gray, calcareous, sandy clay, large phosphate
pebbles ---...... --.--- ...-.. -...- ..----- .. ... .......-.. ..- .....-.... ............. 200-225
Limestone, gray-white to tan, fairly hard, sandy in part, dolomitic;
gray, calcareous clay; fine phosphate sand and pebbles .. .... 225-250
Tampa formation:
Limestone, gray-white to tan, fairly hard, dense, sandy, dolomitic, fos-
siliferous; a few mollusk mold and cast fragments; dark gray chert;
fine sand ..---. ---........ ..----- .....-.. -- ...-.- ... ..- ... .......-.--.... ...... 250-275
Limestone, white, gray, and tan, hard, dense, sandy, phosphatic, solu-
tion cavities; mollusks, ostracods, and Foraminifera, Archaias flor-
idanus, and Sorites sp. present ----..---.---..------. --- 275-300
Limestone, white to gray, fairly hard, dense, sandy, dolomitic and
crystalline in part; phosphate minerals and chert; mollusks, ostracods,
and Foraminifera, Archalas floridanus, Sorites sp. .- --.... 300-325
Limestone, gray and tan, hard, dense, sandy; solution cavities; few
phosphate grains; fossiliferous, as above -.....-----------.- ---. ..-.. 325-350
Limestone, as above .-...----------.... ------.-...-.....-- --- -----3. 50-400
Limestone, tan, hard, dense to soft, granular, porous, sandy in part;
mollusks, echinoid spines, Foraminifera .- ..... 400-410
Suwannee limestone:
Limestone, white to tan, fairly hard, very porous; contains many solu-
tion cavities; small amount of chert; mollusks, echinoid spines, Fora-
minifera ..-..................----------------------.. ................-------...................-....---- 410-425
Limestone, as above; Rotalia mexicana present ..------.. ..-----------..- 425-440
Limestone, creamy white to tan, soft, granular, porous; crystalline
calcite in solution cavities; mollusk casts of crystalline calcite; echi-
noid spines, Foraminifera, Rotalia mexicana abundant .--------...--.. 440-463
Limestone, as above --..-.............-----------------.....--.....-----------.. 463-475
Limestone, as above, dolomitic ... ......... ------------------------------- 475-490
Limestone, as above ---..-..-...........................................------------.......................-------------------...--- 490-530
Limestone, tan, gray and brown, fairly hard, granular and porous in
part, dolomitic and crystalline in part; some pyrite; mollusks, echi-
noid spines, Foraminifera, Dictyoconus cooked present 530-575
Limestone, tan, soft to hard, granular, crystalline in part, dolomitic;
brown, hard, crystalline dolomite; mollusks, echinoids, Foraminifera,
Coskinolina floridana, and Dictyoconus cooked 575-600



















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Ground-water resources of Manatee County, Florida ( FGS: Report of investigations 18 )
CITATION SEARCH THUMBNAILS DOWNLOADS PDF VIEWER PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00001202/00001
 Material Information
Title: Ground-water resources of Manatee County, Florida ( FGS: Report of investigations 18 )
Series Title: ( FGS: Report of investigations 18 )
Physical Description: viii, 99 p. : illus., maps (1 in pocket) ; 23 cm.
Language: English
Creator: Peek, Harry M
Geological Survey (U.S.)
Publisher: s.n.
Place of Publication: Tallahassee
Publication Date: 1958
 Subjects
Subjects / Keywords: Groundwater -- Florida -- Manatee County   ( lcsh )
Water-supply -- Florida -- Manatee County   ( lcsh )
Genre: non-fiction   ( marcgt )
 Notes
General Note: "Prepared by the United States Geological Survey in cooperation with the Florida Geological Survey, Board of County Commissioners of Manatee County, and the Manatee River Soil Conservation 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 - 000958540
oclc - 01747346
notis - AES1350
lccn - a 59009473
System ID: UF00001202:00001

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Table of Contents
    Copyright
        Copyright
    Front Cover
        Page i
    Florida State Board of Conservation
        Page ii
    Transmittal letter
        Page iii
        Page iv
    Table of Contents
        Page v
        Page vi
        Page vii
        Page viii
    Abstract
        Page 1
    Introduction
        Page 2 (MULTIPLE)
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
    Geology
        Page 14 (MULTIPLE)
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
    Ground water
        Page 22 (MULTIPLE)
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
        Page 66
        Page 67
        Page 68
        Page 69
        Page 70
    Salt-water contamination
        Page 71
        Page 72
        Page 73
        Page 74
        Page 75
    Summary and conclusions
        Page 76 (MULTIPLE)
        Page 77
    References
        Page 78
        Page 79
    Table 5. Chemical analysis of water
        Page 80
        Page 81
        Page 82
        Page 83
        Page 84
    Table 6. Water-level measurements
        Page 85
        Page 86
        Page 87
        Page 88
    Table 7. Logs of selected wells
        Page 89
        Page 90
        Page 91
        Page 92
        Page 93
        Page 94
        Page 95
        Page 96
        Page 97
        Page 98
        Page 99
    Map
        Page 100
Full Text






FLRD GEOLIOWC( ICA SURflViEWY~


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Florida Geological Survey shall be considered the copyright holder
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information and permissions.








STATE OF FLORIDA

STATE BOARD OF CONSERVATION

Ernest Mitts, Director

FLORIDA GEOLOGICAL SURVEY

Robert 0. Vernon, Director



REPORT OF INVESTIGATIONS NO. 18




GROUND-WATER RESOURCES OF

MANATEE COUNTY, FLORIDA


By
Harry M. Pcek
U. S. Geological Survey




Prepared by the
UNITED STATES GEOLOGICAL SURVEY
in cooperation with the
FLORIDA GEOLOGICAL SURVEY
BOARD OF COUNTY COMMISSIONERS OF MANATEE COUNTY
and the
MANATEE RIVER SOIL CONSERVATION DISTRICT


TALLAHASSEE, FLORIDA
1958






!' */. "/





FLORIDA STATE BOARD

OF

CONSERVATION


LEROY COLLINS
Governor


I. A. GRAY
Secretary of State



J. EDWIN LARSON
Treasurer



THOMAS D. BAILEY
Superintendent of Public Instruction


RICHARD ERVIN
Attorney General



RAY E. GREEN
Comptroller



NATHAN MAYO
Commissioner of Agriculture


ERNEST MITTS
Director of Conservation





LETTER OF TRANSMITTAL


Oda qeyloaical cSatvemj

Tallahassee

December 15, 1958



Mr. Ernest Mitts, Director
Florida State Board of Conservation
Tallahassee, Florida

Dear Mr. Mitts:

I am forwarding to you a report entitled, GROUND-WATER RE-
SOURCES of MANATEE COUNTY, FLORIDA, which was prepared
by Harry M. Peek, Geologist with the U. S. Geological Survey. This
work was done in cooperation with the Florida Geological Survey, the
Board of County Commissioners of Manatee County and the officials
of the Manatee River Soil Conservation District. It is recommended
that this report be published as Report of Investigation No. 18.

The rapid development and expansion of the coastal areas of Manatee
County combined with increased irrigation of truck farms, cattle lands
and citrus groves, have multiplied the problems of obtaining adequate
supplies of water which meet the quality demands of the various com-
peting interests. This study contributes the needed data for a wise
development of the water resources of the area.

Respectfully submitted,
ROBERT 0. VENON, Director





























Completed manuscript received
April 30, 1958

Published by the Florida Geological Survey
Rose Printing Company, Inc.
Tallahassee, Florida
January, 1959






TABLE OF CONTENTS
Page
Abstract .....-...................-......-........... ....-- .................................................................. 1
Introduction ...........................-.............. ..........................................---- .. ---- 2
Purpose and scope of the investigation ............................................................... 4
Acknowledgments ...............................................................---.....................--........--------..... -- 5
Previous investigations -------........------..........................................................------------------...--..---.......... 5
Well-numbering system ....................................................-..---....-- --------- -------- 6
Geography ........................................................................................... ------------
Climate ..........................--..-...-...-....--....--------.......-------------........................................................---------.. 6
Physiography ..........-.....-............................................................. ....---- ------- 9
History ....................................... ....................................---- ...............................--------------- 11
Population ..............---------------.---...................-...................-----------------.................................................. 12------------12
Industry ..........------.........---.--------......----------.............----...................-------------.....................-........... 12
Transportation ....----------------.................................--...........................----.............-----.----........------........ 14
Geology ..............-............-----------.-....................................------...........---------------------------------------------------..... 14
Pre-T ertiary rocks .................................................................................... ........ 14
T ertiary system ................................................................................................... 14
E ocene series ............................................................................................... 14
Avon Park lim estone ........................................................................... 14
O cala group ......................................................................................... 16
O ligocene series ........................................................................................... 17
Suw annee lim estone ........................................................................... 17
M iocene series ..................................................................................... ........... 18
Tam pa form ation ................................................................................. 18
Hawthorn formation ........................................................................... 21
Pliocene series ..................................................................................... ........ 21
Pleistocene series ......................................................................................... 22
Ground water .....-..-......--------................................--.....................................-----...------------------.--. 22
Principles of occurrence .......--..-.........-----...................--.-----..........................-------------------- 22
Ground water in Florida .----................---- ........--------------....-------------------------------- 28
Artesian water ..........................................-......-............................................. 24
Piezometric surface .....................--...............................................----------...... 24
Ground water in Manatee County .--------------...............--......----.............................-------.---- 24
Artesian water ......................................................----------.................................... 26
Current-meter exploration ...--...........................-------.----..............................-------------.. 27
Artesian head -..-...--.........................................................-------------------------------- 883
Piezometric surface ................................. .. ..................... .............44
Depth to water level below land surface ........................................... 47
Temperature --.--.-------......-....................................--..------------..................----------. 47
Use of water-------- ..........-....................-............---.......----..........--..------....---..-------............ 49
Quantitative studies .......-----------------..............................-..........--------------------------------- 49
Pumping test ..........-- .............--........................................................... 50
Theoretical drawdowns ..................................-.................... .------........ .. 52
Quality of water -...------...-.......-............--------------------------------------------------------------... 56
Constituents and properties -----.....--..-...-...........----...-....................................... -----------------56
Calcium ....................................... ........................-------...........................--... 56
Magnesium ....-------------..................................--......................................---.....----------...........-------. 59
Sodium and potassium -.................-----....-.................................------....------........--..---- 59
Bicarbonate .......---............-----------....................................................................----------- 59
Sulfate -...-...-...-..........................---------..--.....-..-..........................................----------------....----.--...... 59
Chloride ....--------------................-....-..................................... .......................... 59







Iron 2.. ..-... .. ....-.....- ... ............................................................ 62
Fluoride .... ......... ........ ........ ...... .. ......................................... ..... 62
Dissolved solids ... ........- ............................................................. 02
Hardness ....-..----------......------------------------..................................-...--.................. 68
Specific conductance .... ................... .............. ............................------------..-- 08
Hydrogen sulfide ....-------... ---------....... -............... -----...... ............. .................. 68
Hydrogen-ion concentration (pH ) .................................................... 68... 8


Salt-water contamination

Summary and conclusions

IRHefrences


. .. .... .... .... ..... .... ........................ ..... ........... 7 1

........................--------................................ 76

.... ....------ ...............................------... 78






















































vi






ILLUSTRATIONS
Plate Page
1 Map of western Manatee County showing locations of wells........... In pocket
Figure
1 Map of the Florida Peninsula showing the location of Manatee County ...... 3
2 Map of eastern Manatee County showing locations of wells ........................... 7
3 Precipitation and temperature at Bradenton ...............................................------------------ 8
4 Map of Manatee County showing the Pleistocene terraces ........-................. 10
5 Population growth in Manatee County and the cities of Bradenton
and Palmetto, 1890-1950 ......-.............................................................-........... 13
6 Cross sections showing the geological formations penetrated by
water wells in M anatee County ..... ................................. ....................... .. 16
7 Structure-contour map of the top of the Suwannee limestone in
Manatee County ......................................--------------------.........-...............................-----............. 19
8 Structure-contour map of the top of the Tampa formation in
M anatee County ................................................................................................. 20
9 Map of the Florida Peninsula showing the piezometric surface ---......------.. 25
10 Graphs showing data from well 27-28-2, seven miles southeast of
Bradenton ..............................................................................-----....-..................-----------..-- 27
11 Graphs showing data from well 28-29-8, six miles southeast of
Bradenton ....-........--.....-......-....---------------...................-.............-.....--.--------................-...........------........--... 28
12 Graphs showing data from well 28-14-4, near Cortez ........................................29
13 Graphs showing data from well 29-29-4, five miles east of Bradenton .......... 80
14 Graphs showing data from well 30-28-1, seven miles east of Bradenton ........ 31
15 Graphs showing data from well 88-32-5, five miles northeast of Terra Ceia.... 32
16 Graphs showing data from well 29-37-10, four miles west of Bradenton ....-.. 34
17 Hydrograph of well 26-18-1 and rainfall at Bradenton ...--................---.......-----...---..- 36
18 Hydrographs of wells 27-36-3, 28-31-1, and 31-34-6 ..............-...---.........----- .------..... 37
19 Hydrographs of wells 17-11-1, 24-30-1, 26-41-2, 28-23-1, and 29-37-7 .-..-....---. 38
20 Graphs showing relation between water levels and chloride content of
water in wells 23-38-3, 28-41-4, and 29-40-10 .....-......--..................-------------......-......-..-....-- 39
21 Graphs showing relation between water levels and chloride content of
water in wells 27-34-1, 27-38-7, and 27-41-1 .--......------..-.........-.........-..-...-................--.... ------40
22 Graphs showing relation between water levels and chloride content of
water in wells 29-42-8, 81-37-12, and 83-35-4 .--....----------...........-...--..-..........-....-....--...-..--. 41
28 Graphs showing relation between water levels and chloride content of
water in wells 80-39-11, 31-43-3, and 31-44-38 ...................................................42
24 Effects of earthquakes and changes in barometric pressure on the water
level in well 26-18-1, 12 miles northwest of Myakka City ..........--------....-......-....-...-- 48
25 Map of Manatee County showing the piezometric surface in
September 1954 -....--.---..........--...........-..-.................................................----....--.........---....--..- 45
26 Map of Manatee County showing the piezometric surface in June 1955 ...... 46






27 Map of Manatee County showing the area of artesian flow and the
depth to water in June 1955 ..-..-------------.........-------..................---------............................................- 48
28 Sketch of pumping-test site, showing location of pumped well in
relation to observation wells ................... ............................. ......... ......-........... 50
29 Graphs showing drawdown and recovery of water levels in observation
wells during pumping test .......................-................................. ---.................... 51
'30 Logarithmic plot of drawdowns in observation wells versus t/r ..............------ 58
31 Logarithmic plot of recovery in observation wells versus t/r ................-----.... 54
32 Semilog plot of recovery versus t for well 84-30-3, seven miles
northeast of Bradenton .---. -------.. --------... --......---.............--..----------...--.......-. 55
33 Graph showing theoretical drawdowns in the vicinity of a well being
pumped at a rate of 1,000 gpm for selected periods of time ....------.......-............. 57
34 Map of Manatee County showing wells sampled for chemical analysis
and location of line A-B in figure 44 .----..---------------.................................................. 58
35 Map of western Manatee County showing sulfate content of water from
wells that penetrate the Suwannee limestone and older formations .-..........------.. 60
36 Map of western Manatee County showing sulfate content of water
from the Tampa formation .. ------------------..... ...........................---------............ 61
37 Map of western Manatee County showing chloride content of water from
wells that penetrate the Suwannce limestone and older formations ...........- 63
38 Map of western Manatee County showing chloride content of water
from the Talampa form action .......................................................................... ........ 64
39 Map of western Manatee County showing chloride content of water
from the Hlawthorn and younger formations .--------..-..--....-...-...----..-------........ 65
'10 Map of western Manatee County showing concentration of dissolved solids
in water from wells that penetrate the Suwance limestone and older for-
ations .. ..... ....-----------....... -- --------.......... ..-........-............ 66
41t Map of western Manatee County showing concentration of dissolved
solids in water from the Tampa formation -- .---..-------...---.......-------.......-... 67
42 Map of Manatee County showing hardness of water from wells that
penetrate the Suwannee and older limestones ....------.....--------......--------................. 69
43 Map of Manatee County showing hardness of water from
the Tampa formation ----------..... ..................-------------------......---... 70
41 Graph showing the principal constituents of water from selected
wells along line A-B in figure 34 ..--------..--....-------............. --------------........... .... 72
45 Graph showing data from well 27-36-1, four miles southwest
of Bradenton ..- -- ---------... ..................................... ---------------- 74
46 Graph showing chloride content and temperature of water from well
29-10-3, two miles north of Cortez --.-..---.------------------............. ........... ........ 75
Table
1 Pleistocene terraces and shorelines in Manatee County ................................ 9
2 Agricultural use of land in Manatee County in 1954 .--------.....................................-- 12
3 Geologic formations of Manatee County ---..... ..................................................... 15
4 Stratigraphic nomenclature of the upper Eocene in Florida ............................ 17
5 Chemical analyses of water from wells in Manatee County ............................ 80
6 Water-level measurements ...--.....---..............-------------------.......................................................... 85
7 Logs of selected wells in Manatee County ..................................................... 89
viii







GROUND-WATER RESOURCES OF
MANATEE COUNTY, FLORIDA

ABSTRACT

Manatee County comprises an area of about 800 square miles adjacent
to the Gulf of Mexico in the southwestern part of peninsular Florida.
Deposits of sand, limestone, and shells, mainly of Pleistocene age, but
probably partly of Pliocene age, are exposed at the surface throughout
most of the county. These range in thickness from a few feet to about
90 feet. They are underlain by interbedded marl, limestone, and sand
of the Hawthorn formation of middle Miocene age. The Hawthorn
formation is underlain, at depths ranging from about 175 to 350 feet
below sea level, by a series of limestones of Tertiary age which have
a total thickness of more than 4,000 feet. The upper part of the limestone
section consists of the Avon Park limestone of late middle Eocene age,
the Ocala group' of late Eocene age, the Suwannee limestone of Oligo-
cene age, and the Tampa formation of early Miocene age.
Usable quantities of ground water are obtained in the county from
all formations penetrated by wells. Small supplies for domestic use are
obtained from the surficial deposits of sand and shells, which contain
water under nonartesian conditions. Most domestic supplies, however,
are obtained from the permeable beds in the upper part of the Hawthorn
formation and from younger formations in which the water is under a
slight artesian pressure.
The Suwannee limestone and Tampa formation are the principal
sources of artesian water. All the large industrial, irrigation, and public
supplies are obtained from them, but many domestic and small irrigation
supplies are obtained from permeable beds in the Hawthorn formation,
which serves as a confining bed for the water in the underlying limestones.
Records of the fluctuations of artesian head show that the withdrawal
of large quantities of artesian water causes an extensive lowering of the
piezometric surface. During periods of heaviest withdrawal, the piezo-
metric surface declines at least four or five feet throughout the county
and as much as 10 feet at some places. The magnitude of the seasonal
fluctuations has increased and a progressive decline in the artesian head

'The stratigraphic nomenclature used in this report conforms to the usage of
the U. S. Geological Survey with the following exceptions: the Ocala limestone is
herein referred to as the Ocala group, and the Tampa limestone is referred to as
the Tampa formation. These exceptions are made in order to conform to the nomen-
clature used by the Florida Geological Survey.






FLORIDA GEOLOGICAL SURVEY


has occurred in some parts of the county since about 1948, because of an
increase in water use.
Determinations of the chloride content of the artesian water indicate
salt-water contamination in a zone about 3 to 10 miles wide along the
coast. The degree of contamination increases with depth and seaward.
Throughout most of the zone, the water in the Tampa formation contains
less than 250 parts per million (ppm) of chloride and is suitable for
most purposes, but some wells in the vicinity of Palma SolaBay yield
water from the Tampa formation containing more than 400 ppm of
chloride. The chloride content of the water in the Suwannee limestone
is more than 2,000 ppm at some places but is generally less than 500 ppm.
The water in the Eocene formations along the coast is probably too
salty for most uses.
Periodic analysis of the water from many wells shows that the
chloride content varies with the seasonal fluctuations of artesian pressure
head. Some wells that show a progressive decline in artesian pressure
head also show a progressive increase in chloride content of the water,
indicating that significant declines in head result in upward movement
of salty water from the deeper formations. This upward movement is
probably retarded considerably by the beds of low permeability that
separate the principal water-bearing zones.
INTRODUCTION
Ground water is the principal source of fresh water for public, domes-
tic, agricultural, and industrial supplies in Florida. The increased use
of ground water in the State, resulting from the growth of population
and industry, has caused a large number of water-supply problems,
particularly in coastal areas where population and industry are concen-
trated. Most of the water-supply problems in these areas can be classified
as "salt-water" problems.
In much of the coastal area of southern Florida, a part or all of the
formations capable of yielding large quantities of water contain naturally
salty water. Thus, the problem in this area is one of finding supplies of
fresh water that are adequate to meet the increased demand and are
economically feasible to develop. The problem in other areas is to
protect present supplies from contamination by salt-water encroachment
from the sea or from underlying formations that contain naturally salty
water. Encroachment of salt water from either source occurs as a result
of excessive lowering of the fresh-water pressure head.
A large part of western Manatee County (fig. 1) is used for growing
winter vegetables and citrus fruits, and large quantities of artesian water







REPORT OF INVESTIGATIONS No. 18


ApotcAlmalS stele


Figure 1. Map of the Florida Peninsula showing the location of Manatee County.






FLORIDA GEOLOGICAL SURVEY


are used for irrigating these crops. The large withdrawals of artesian
water for irrigation and for processing agricultural products result in a
considerable seasonal decline of the artesian head, particularly in the
western part of the county. This seasonal decline of artesian head has
increased in proportion to the increase in withdrawal of artesian water.
The progressive increase in seasonal decline of the artesian head
intensifies the danger of salt-water encroachment in the artesian aquifer.
The presence of salty water in the artesian aquifer in parts of the coastal
area of the county suggests that slight encroachment may already have
occurred. Recognizing this possibility, and in response to the concern
expressed by the farmers of the county, the Board of County Commis-
sioners and the Supervisor of the Manatee River Soil Conservation Dis-
trict requested the U. S. Geological Survey and the Florida Geological
Survey to make an investigation of the ground-water resources of the
county. As a result of this request, an investigation was begun in Decem-
ber 1950 by the U. S. Geological Survey in cooperation with the above
agencies.

PURPOSE AND SCOPE OF THE INVESTIGATION
The purpose of the investigation was to make a detailed study of the
geology and ground-water resources of the county, principally to deter-
mine whether salt-water encroachment had occurred or was likely to
occur. The investigation consisted of the following phases:
1. An inventory of more than 900 selected wells, to obtain information related
to the occurrence and use of ground water in the county.
2. A collection of data on water levels for use in determining progressive trends
and the magnitude of seasonal fluctuations, and in constructing maps show-
ing the altitude to which water will rise in artesian wells.
3. Determinations of the chloride content of water from about 750 wells, to
define the areas in which the ground water is relatively salty.
.I. Periodic determinations of the chloride content of water from selected wells,
to find the relation between salinity and artesian pressure.
5. A study of geologic conditions governing the occurrence and movement of
ground water.
f(. Exploration of selected wells with deep-well current meter, to determine
the depth and thickness of the principal water-bearing zones.
7. Chemical analyses of water samples from selected wells.
8. Studies to determine the water-transmitting and water-storing properties of
the water-bearing formations.
The field work of this investigation from December 1950 to January
1954 was done by R. B. Anders of the U. S. Geological Survey. An
interim report covering this part of the investigation was published in
March 1955 (Peek, H. M., and Anders, R. B., 1955). The field work from
January 1954 until the investigation was completed in December 1955






REPORT OF INVESTIGATIONS No. 18


was done by the author of the present report. The present report includes
most of the data from the earlier field work and report.
ACKNOWLEDGMENTS
Acknowledgment is made to H. 0. Kendrick, County Agent, and his
staff and to E. L. Ayers, County Agent during the first part of the
investigation, for the helpful assistance given throughout the investiga-
tion. I. H. Stewart of the Soil Conservation Service, U. S. Department
of Agriculture, and Fonzie Outlaw and L. Rhinehart of his staff, con-
tributed much valuable information and gave assistance in many ways
toward completion of the field work.
Appreciation is expressed to the well drillers who furnished informa-
tion and collected rock cuttings and water samples. These include:
Charles and Lowell Pemelman, W. Reddick, T. M. Shacklee, and Dale
Young, of Bradenton; C. D. Cannon, J. 0. Mixon, and E. Moran, of
Palmetto; E. E. Boyette, of Ruskin; J. P. Adams and R. Phillips, of
Sarasota.
Special thanks are due the many well owners for their cooperation
in contributing information and otherwise aiding the investigation.
PREVIOUS INVESTIGATIONS
No detailed investigations of the geology and ground-water resources
of Manatee County had been made prior to the present study. However,
several short studies were made, and the results have been published in
the reports of the Florida Geological Survey and the U. S. Geological
Survey. Some of the more informative reports are described below.
A report by Matson and Sanford (1913, p. 237, 254, 362-364; pl.5)
includes a section on the geology and water supply of Manatee County
and a table of selected well records. A report by Sellards and Gunter
(1913, p. 266-269; fig. 16) also includes a brief summary of the geology
and ground-water resources of the county and a map showing the area of
artesian flow.
A report on a reconnaissance investigation of several counties in the
State by Stringfield (19388, p. 8-5) contains a brief discussion of the
geography, geology, and ground water of Manatee County. Another
report by Stringfield (1936, p. 145, 164, 167, 170, 180, 182, 191, 192; pl.
10, 12, 16), which gives the results of a study of the artesian water of
the Florida Peninsula, contains water-level measurements and other data
on about 90 wells in Manatee County. The 1936 report also includes
maps of the Florida Peninsula showing the area of artesian flow, the
height above sea level to which water in the principal artesian aquifer
will rise in wells, and the areas in which water having a chloride content




FLORIDA GEOLOGICAL SURVEY


of more than 100 ppm is present at moderate depths.
The formations that crop out are briefly described in a report on the
geology of Florida by Cooke (1945, p. 138, 158, 157, 208, 223, 807). A
report by MacNeil (1950, pl. 19) describes Pleistocene shorelines in
Florida and Georgia and contains a map showing the general configura-
tion of these shorelines in Manatee County.
Chemical analyses of water from several wells and springs in Manatee
County are included in a report by Collins and Howard (1928, p. 220-
221) and a report by Black and Brown (1951, p. 77).
WELL-NUMBERING SYSTEM
The well-numbering system used in this report is based on latitude
and longitude. As shown in plate 1 and figure 2, the county has been
divided into quadrangles by a grid of 1-minute parallels of latitude and
1-minute meridians of longitude. The wells have been assigned numbers
according to their location within this grid. Each well number consists of
three parts: The first part is the latitude, in minutes, of the south side of
the 1-minute quadrangle, the second part is the longitude, in minutes, of
the east side of the quadrangle, and the third part is the number of the
well within the quadrangle. For example, the number 27-34-3 designates
the third well listed in the quadrangle bounded by latitude 27' on the
south and longitude 34' on the east. The degrees of latitude and longi-
tude are not included as a part of the well number because they are the
same for all wells in the county (fig. 1). Well locations are shown on
plate I and figure 2. Complete well descriptions, locations, and other
data are to be published as Florida Geological Survey Information Cir-
cular No. 19, and may be obtained for one dollar per copy.
GEOGRAPHY
Manatee County comprises an area of about 800 square miles adja-
cent to the Gulf of Mexico in the southwestern part of the Florida
Peninsula (fig. 1). It is bounded on the north by Hillsborough County,
on the east by Hardee and De Soto counties, on the south by Sarasota
County, and on the west by Tampa Bay and the Gulf of Mexico.
CLIMATE
Manatee County has a subtropical climate and a mean temperature
of about 72F. According to the records of the U. S. Weather Bureau,
the mean monthly temperatures at Bradenton range from 61.50F in
January to 81.2F in August, as shown graphically in figure 3. For com-
parative purposes, the figure includes also the average maximum and
minimum monthly temperatures during 1954.

























EXPLANATION
0I
Well penetrating aquifer above the Floridan
showing number assigned to well.
.2
Well penetrating the Floridan aquifer.
showing number assigned to well.


270 12'U-
82015'


82*10'
SARA SOTA


COUNTY


0 I 2 3 4 Miles

Figure 2. Map of eastern Manatee County showing locations of wells.


27023'



2720'


V







o

o
27J15'
LaJ
0



2720'



z
0

0






27 15'


82005'








8













4

-E

0.



























'S

'.5


Figure 3. Precipitation and temperature at Bradenton.


FLORIDA GEOLOGICAL SURVEY
















7 Aver ge moamum 5954
?-90
7T7- NVCA A A T O N


W 60 -- ( v go minimum m 195 d --


17' 40

SSEPT OCT NOV DEC JAN FEB MAR APR MAY JtIM JULY AUG SEPT OCT NOV DEC






REPORT OF INVESTIGATIONS No. 18


The average annual rainfall at Bradenton from 1880 through 1955
was 54.6 inches (fig. 3) but it ranged from as much as 75.78 inches in
1900 to as little as 29.45 inches in 1944. The average monthly rainfall
during the period of record ranged from 1.84 inches in November to 9.5
inches in July. About 60 percent of the yearly precipitation occurs
between June 1 and September 30.
PHYSIOGRAPHY
Manatee County lies within the Terraced Coastal Lowlands as de-
serilbed by Vernon (1951, p. 16), a subdivision of the Coastal Plain Prov-
ince. The topography is largely controlled by a series of marine terraces
formed during Pleistocene time, when the sea several times stood above
or below its present level.
The history of the Pleistocene epoch and the marine terrace deposits
in Florida that are associated with the fluctuations of sea level are dis-
cussed in detail in reports by Cooke (1945, p. 11-13, 245-312), Vernon
(1951, p. 15-42, 208-215), and Parker (1955, p. 89-124). The rise and fall
of sea level are attributed to the advance and retreat of the great conti-
nental ice sheets; the sea level declined as the glaciers expanded and rose
as they melted. When the sea was relatively stationary for long periods,
shoreline features and marine plains were developed. The remnants of
five marine terraces and four shorelines in Manatee County have been
previously mapped (Cooke 1945, figs. 43-47; Parker 1955, pl. 10) as listed
in the following table:
TABLE 1. Pleistocene Terraces and Shorelines in Manatee County
Terrace Altitude of shoreline
(feet above msl)
Sunderland -----.............--......-- ---------------------------.1701
Wicomico ...............................................-------------.......................--------------------------100
Penholoway .---------------....................................................................................----------------------- 70
Talbot ..-.............------..--.....---..............------------- -- 42
Pamlico ........................................................................................................-- 25
,The highest land surface in Manatee County, about 140 feet above sea level,
represents a shallow sea bottom of Sunderland time.
Figure 4 shows the general configuration of the Pleistocene terraces
in the county as determined from aerial photographs, topographic maps,
and field observation. The highest and oldest surface represents an off-
shore portion of the Sunderland terrace (Cooke 1945, p. 278-279), which
was formed when the sea was about 170 feet above the present level
and covered practically all of southern Florida, including Manatee
County. During Wicomico time, when the sea was at an altitude of
about 100 feet, the only land area was in the northeastern part of the
county. It consisted of the Sunderland terrace and associated islands.












arios'


-. '0
~,.


.:..:. .* .b



meow. .



IL-










: : : :: : m. : .~r
WSW 25 2' 9' 0
CO)


EXPLANATION

Swmdw'Iandt terrace
Wmemrsico terrace
SPenhateway terrace
rZ2 Tolot terrace
Pamwlico terrace

02


asc00taTY
SARASWfA COUNTY
25! 2C Is' ad eraS'


Figure 4. Map of Manatee County showing Pleistocene terraces.


*27*40


aszc"


82"40'


4w-- -
Poem"






REPORT OF INVESTIGATIONS No. 18


The shoreline of the Wicomico sea is marked by an escarpment that is
well preserved in many places. The base of the scarp is generally at an
altitude of about 90 to 100 feet.
The Penholoway terrace was formed when the sea was about 70 feet
above the present level and covered about two-thirds of the present
land area of the county. The shoreline of the Penholoway sea is marked
by a scarp that is well preserved in many places. The altitude of the
scarp base is generally about 60 to 70 feet.
The Talbot terrace was formed when the sea was 42 feet above the
present sea level and covered most of the western part of the county.
The shoreline of the Talbot sea is poorly preserved in most places and
is generally difficult to trace in the field. In the southeastern part of the
county, however, the shoreline is fairly well defined by a low escarp-
ment whose base is at an altitude of about 40 feet.
The Pamlico terrace is the youngest Pleistocene terrace that has been
recognized in the county. It was formed when the sea was about 25 feet
above the present level. A well-preserved scarp, whose base is at an
altitude of 20 to 25 feet, and other shoreline features generally mark
the shoreline of the Pamlico sea.
The Pamlico terrace forms a relatively flat coastal lowland that is
generally less than 20 feet above sea level, although it contains a few
low hills and ridges that rise to altitudes of 80 feet or more. The older
terraces form an upland of rolling hills that extends inland from
the Pamlico shoreline and gradually rises toward the northeast to an
altitude of about 140 feet. The Talbot and Penholoway terraces have
been modified to some extent by stream dissection but consist predomi-
nantly of low rolling hills having broad, relatively flat summits at alti-
tudes of about 50 to 80 feet. The Wicomico and Sunderland surfaces
have been more completely dissected by streams and the relief is more
pronounced; however, in many places they are still relatively flat and
drainage is poorly developed.
The surface drainage of the county is principally through the Mana-
tee, Little Manatee, and Myakka rivers and their tributaries. Much of
the coastal area is drained by small streams that empty directly into the
Gulf of Mexico. A large part of the county, however, is poorly drained
and contains many ponds anid swamps. A network of canals has been
dug throughout most of the county to supplement the natural drainage.
HISTORY
Manatee County was established in 1855 and originally included
the area that is now Hardee, De Soto, and Sarasota counties. De Soto






12 FLORIDA GEOLOGICAL SURVEY

County was separated from Manatee County in 1887, and Sarasota
County was created from the southern part of Manatee County in 1921.
The county received its name from the manatee, or sea cow, which
inhabited the surrounding waters. The Spanish explorer, Hernando De
Soto, landed on Terra Ceia Island in 1539. His army landed on the south
side of the Manatee River at Shaws Point, which is now a national
monument.

POPULATION
The population of the county in 1950 was 34,547, an increase
of 32 percent from that of 1940 (fig. 5). About 90 percent of the total
population is in the western one-third of the county. Bradenton, the
county seat and largest city, had a population of about 13,000 in 1950.
The growth of population in Bradenton and Palmetto from 1895 through
1950 is shown graphically in figure 5.

INDUSTRY
The principal sources of income are agriculture and associated indus-
tries, commercial fishing, and the tourist trade. The mild climate and
the ready supply of water for irrigation have been the predominant
factors in making the county one of the State's most productive agri-
cultural areas. The agricultural use of land in the county in 1954, accord-
ing to the U. S. Bureau of the Census, is given in table 2. In 1948 more
than 3.5 million pounds of food fish were caught and marketed, in addi-
tion to shellfish, crabs, shrimp, and miscellaneous seafoods. The mild
climate, beaches, waterways, and game fish annually attract thousands
of tourists from all parts of the country. Mineral products from the
county include limestone, dolomite, sand, and shells.

TABLE 2. Agricultural Use of Land in Manatee County in 1954
Acres
Approximate land area ......---......--..--....---.......................-------------------------................................... 448,640
Farmland .....-------------....---..........-.....-...........--------..-....-.............-.................-...............-... 809,125
Cropland harvested ---------..-........-..-.....-.......-----.........--..----...-..-..-............. 15,614
Vegetables .---------...........-.....-----...--..-----...-....-...-........ 4,558
G roves ... ...................................................... 8,407
Flowers and shrubs .-..--....-------...-......---..........-..-.......... 2,082
O their ......... .. ............................................ 567
Cropland not used .................................................................. 7,830
Total land pastured ..................................---------------------------........................ 266,803
Cropland pastured .-.................-----....----...........-............- 17,619
Pastureland ......................................................... 109,567
Woodland pastured ......-..-------...-...---.....-.....-.................. 189,617
W oodland not pastured ............................................................. 10,602
Other land not pastured ............................................................ 8,776








REPORT OF INVESTIGATIONS No. 18 18


14



CITY OF 3RADE NTON .
10



















CITY OF PALMErTO
il0l




- -o- I I I I I I I ... .. ..r-7. .
LiI) ___" ll_. Il
2I / .
(1)6- 11.. .
0 .
..I-. . .
zI~ . .


iia i l.. .. ..""- '


Figure 5. Population growth in Manatee County and the cities of Bradenton and
Palmetto, 1890-1950.






FLORIDA GEOLOGICAL SURVEY


TRANSPORTATION
U. S. Highways 19, 41, and 301, in addition, to many State highways,
provide easy access to all parts of the county and to adjacent counties.
The Atlantic Coast Line Railroad and the Seaboard Air Line Railroad
provide rail transportation, and scheduled air flights and bus service
also are available.

GEOLOGY
Thec known geologic formations of Manatee County range in age from
Recent to Cretaceous. They are listed and briefly described in table 3.
The surface formations consist predominantly of undifferentiated depos-
its of Pleistocene and, probably, Pliocene age; however, beds of Miocene
age are exposed at some places. The subsurface formations are described
on the basis of studies of rock cuttings, electric logs, and drillers logs of
wells in Manatee and adjacent counties. Detailed logs of selected wells
are included in table 7.
PRE-TERTIARY ROCKS
Rocks older than middle Eocene in Manatee and adjacent counties
are known only from a few deep oil-test wells. The data from these wells
indicate that rocks of Cretaceous age occur at a depth of about 5,000
feet in Manatee County. Well 26-22-1, drilled in 1955 by the Magnolia
Petroleum Corporation, entered the Upper Cretaceous at 5,120 feet
below sea level and ended in Cretaceous rocks at more than 10,000 feet
below sea level. The Cretaceous rocks consist of interbedded shale,
limestone, and anhydrite and contain highly mineralized water. Water
from near the bottom of well 26-22-1 contained more than 100,000 ppm
of chloride, whereas sea water generally contains less than 20,000 ppm of
chloride.
TERTIARY SYSTEM
The formations of Tertiary age in Manatee County and their approxi-
mate thicknesses are listed in table 3, but only those formations that are
penetrated by water wells (fig. 6) are discussed in this report.
EOCENE SERIES
Avon Park Limestone: The upper part of the late middle Eocene
in Florida was named the Avon Park limestone by the Applins (1944, p.
1680, 1686). It crops out in Citrus and Levy counties and is the oldest
formation exposed at the surface in Florida. It is also the oldest forma-
tion penetrated by water wells in Manatee County.
Lithologically, the Avon Park, in the county, ranges from white or
tan, fairly soft, coquinoid or granular limestone, to dark brown, hard,
crystalline dolomite. Most of the formation is dolomitized to some








REPORT OF INVESTIGATIONS No. 18


Table 8. Geologic Formations of Manatee County


Pamlico sand1
Older terrace
deposits


Caloosahathooee
imarl?
Boneo Valley
formation
Hawthorn
formation




Ta'mpa
formation


uiwastono
lliestoneo


Ocala group




Avon Park
limestono



Lako City
limestone
Oldsmar
limostoneo


Codar Keys
formation


Soil, muok, alluvium, sand.


Rand, shells, limestone,
Sand,


Marl, sand and gravol of quartz and( phosphate, shells,
1)ono fragments.
Sand and gravel of quartz and phosphate; clay, bone
fragments.
Clay and marl, gray, greonish and bluish gray, sandy,
phosphatio, oalcaroous, interboddod with sandy
lmostono, si, sand, and shells. The sand, sholl, and
li nostono bode are the souroo of small water supplies.
The water in the Hawthorn formation is undor ar-
tosian pressure and is gonorally loss minutralizod than
the water in the Tampa and oldor formations.
Limestone, white, gray and tan, gonorally hard, d(ono,
sandy, phosphatio in part, silioifiod in part, fossil-
iforous. Porosity due primarily to solution cavities.
Yields largo quantities of artesian water.
Limestone, oroamy white and tan soft to hard, granu-
lar, porous, crystalline, and dolomitic in part, very
fossiliforous. Gonorally a more productive source of
artesian water than tho T'ampa, but water is some-
what more mineralized in theo eastern part of the
county.


Limestone, white, croam, tan, chalky, s)'ft, granular,
porous, coquinoid in pait, with some hard, denso
layers and some thick beds of brown, crystalline
dolomite. Probably a productive source of artesian
water but penetrated by only a few wells. Water is
relatively high in mineral content in the coastal area.
Li'nostono, cream, tan, and brown, soft to hard, granu-
lar and coquinoid in part, crystalline and dolomitio
in part, very porous. Probably a very productive
source of water, but tapped by very few wolls. Water
is probably high in mineral content in theo coastal
area.
Limestone, cream and tan, chalky to granular, dolo-
mitio and gypsiferous in part, and very fossiliferous
in part.
Limestone, tan and brown, granular, porous; inter-
bedded with chort, anhydrite, and tan to brown,
crystalline, porous, dolomite.


Limestone, cream to tan, fairly hard, granular, gyp-
siforous, interbodded with tan to brown, crystalline
dolomite, fossiliferous in part.


Limestone, shale, anhydrite


8ysi om


Sorios


Formnation


300-325




700




500

950


2,000


-- --------- I ----- --c--.-------- -.I ----- --------- --------- -----~~---- ------,,,,I,,-,,~.


--------I-----------I-------~---~---- -------- 1------------11~


-------II c~~I-I- --I-~-~-~---I-.


- ----- -----------------------


Thicknoss
(foot)

0-20


0-20
0-(10


0-10
0-30?

150-300




125-235



150-300


Al






FLORIDA GEOLOGICAL SURVEY


41


PY I;INI titii I l


II ~OHMA I (AION NO(
,AAT(( (N IO(MAT~tN (MIOCE NH
fUIIMAI ION (tC i

IiA A (61001) (f Lid NCI- *' Ir-


Figure 6. Cross sections showing the geologic formations penetrated by water wells
in Manatee County.

degree and much of it is very fossiliferous, containing bryozoans, coral,
(ehinoids, mollusks, and many foraminifers, including specimens of
Dictyoconus cooked, Lituonella floridana, Spirolina coryensis, and Valvu-
lina intermedia.
The Avon Park limestone is about 700 feet thick in Manatee County
and is generally very permeable, owing to the extensive development of
solution channels. Several wells obtain water from the Avon Park and
it is probably a productive source of artesian water throughout the
county. In the coastal area, however, the water probably is highly
mineralized.
Ocala Group: Until recent years, all the limestones of late Eocene
(Jackson) age in peninsular Florida were considered a single formation,
the Ocala limestone. As shown in table 4, Cooke (1945, p. 53-62) and
the Applins (1944, p. 1683) referred all the late Eocene limestone to the
Ocala limestone; however, the Applins recognized an upper and a lower






REPORT OF INVESTIGATIONS No. 18


member on the basis of lithologic and faunal differences. After comple-
tion of his studies in Citrus and Levy counties, Vernon (1951, p. 111-171)
separated the late Eocene limestones into two formations: the Ocala
limestone, restricted to the upper part, and the Moodys Branch forma-
tion. Vernon also divided the Moodys Branch formation into two mem-
bers: the Williston member (upper) and the Inglis member (lower).
Table 4. Stratigraphic Nomenclature of the Upper Eocene in Florida

U.S. Geological Survey Floridat Geological Survey
Cooke (1945) Applins (1944) Vernon (1951) Puri (1953)
Upper OcIal liiiestono Crysitl
iieiumboer (restricted) River
formation
Oeala Ocala Ocala
lineA1tone limestone groups
Lower Moodys Williston Williston
member Branch member formation
formation
Inglika Ingli
moimbor formation

Puri (1953, p. 130) changed the Ocala limestone (as restricted by
Vernon) to the Crystal River formation and gave formational rank to the
Williston and Inglis 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.
The Ocala group lies unconformably on the Avon Park limestone in
Manatee County and is about 800 to 325 feet thick. The upper part con-
sists predominantly of cream, tan and grayish-tan, soft, chalky, highly
fossiliferous limestone. The lower part is similar but contains beds of
brown and tan, hard, crystalline dolomite and dolomitic limestone. The
Ocala group is penetrated by only a few wells in the county, although
it may be a productive source of artesian water. In the coastal areas,
however, the water in the Ocala group has a relatively high mineral
content.

OLIGOCENE SERIES
Suwannee Limestone: As used in this report, the Suwannee limestone
includes all deposits of Oligocene age in Manatee County. The Suwannee
is differentiated from the underlying Eocene formations and overlying
Miocene formations on the basis of lithology and fossils, and is separated
from these formations by unconformities.
The upper part of. the Suwannee is generally a creamy-white to tan
soft to hard granular porous limestone, with some beds of crystalline and






FLORIDA GEOLOGICAL SURVEY


dolomitic limestone. It contains many echinoids, mollusks, and foramini-
fers. The lower part is generally tan to gray, and it is harder, more crys-
talline, more dolomitic, and less fossiliferous than the upper part. Dictyo-
conus cooked and Coskinolina floridana are found in the Suwannee in
the western part of the county. They are generally restricted to the lower
part of the Suwannee and may be diagnostic of the lower Suwannee in
that area. However, these foraminifers were not found in the Suwannee
in the eastern part of the county. Specimens of Rotalia mexicana are
fairly abundant in the Suwannee limestone throughout the county.
The contours on the map in figure 7 represent the approximate alti-
tude and the configuration of the top of the Suwannee limestone in
Manatee County. The contours were drawn on the basis of well cuttings,
drillers logs, and electric logs. The dashed lines in the eastern part of
the county, where no control wells were available, were drawn on the
basis of information from wells in adjacent counties. As shown on this
map, the top of the formation ranges in depth from about 325 feet below
sea level in the northeastern part of the county to more than 550 feet below
sea level in the southern and southeastern parts of the county. The thick-
ness of the formation ranges from about 150 feet in the northeastern part
of the county to about 300 feet in the southwestern part.
The Suwannee is the most productive source of artesian water gen-
erally tapped by wells in the county. In the coastal area, the water in
the Suwannee is somewhat more mineralized than the water in the over-
lying Tampa formation.

MIOCENE SERIES
In this report, the deposits of Miocene age in Manatee County are
referred to the Tampa formation of early Miocene age (Cooke 1945, p.
107) and the Hawthorn formation of middle Miocene age. Both the
Tampa and Hawthorn formations are of marine origin, but they repre-
sentit different depositional environments and are probably separated by
an Inicoilformity.
Tampa Formation: The Tampa formation lies unconformably on the
Suwannee limestone of Oligocene age and consists of white, gray and
tan, hard, dense, sandy limestone which contains fine-grained phosphorite
inii some places. The limestone is crystalline and dolomitic, in part, and
contains thin beds of chert. It is generally fossiliferous, containing echi-
noid plates and spines, ostracods, foraminifers, and many molds and
casts of mollusks. Specimens of the foraminifers Archaias floridanus and
Sorites sp. are fairly abundant throughout the formation.
The contours on the map in figure 8 represent the approximate alti-
tude and configuration of the formation. They were drawn on the basis






ev4 40.
27*39.----


I


351 S'


1 1Li


I TK 9 4


I


II AcPOiS14


~fl77Irf


I \ I


27'


0
0



z






0
z

z

00>


, ; I _i I -. __M ;hoc_ i N i





he r II


74i


I I 1 rl i ~--I- I II


%. .
lk,


-a


Srftr


.....*


1 \


7


--I -"r ^ 770 P :S *- T- ,














EXPLANATION 475-

Well (drillers log available) -
525-r
Well (cuttings available) \ _

Well (electric log available 0 4m N \ T '* \

Well (cuttings and electric log available) .\

500- -- 500 .- \
Depth, ,n feet below mecn see level

Q \%
E P I % -, 0
Figure 7. Structure-contour map of the top of the Suwannee limestone in Manatee
County.























2 10'71

















Wenl (cuttings avokacee) \
o *
Well electricc log c,,ilblde) cr. ,^ r-s~-* 25 I? ..

Well (cuttings and eleCereC log ovCocble) -

200200 L
Depth, in feet below mean sea level

Dp. t,-.-- below......... -.
-'* ,c ~c"' *2'CS'


Figure 8. Structure-contour map of the top of the Tampa formation in Manatee
County.






REPORT OF INVESTIGATIONS No. 18


of information from electric logs, drillers logs, and the study of well
cuttings. The dashed lines in the eastern part of the county, where control
wells were not available, were drawn on the basis of information from
wells in adjacent counties. As shown on the map (fig. 8) the top' of
the Tampa ranges in depth from about 200 feet below sea level in the
northern and northeastern parts of the county to more than 350 feet
below sea level in the southwestern part. The thickness of the formation
ranges from about 125 feet in the northeastern part of the county to about
235 feet in the southeastern part. The average thickness is about 150 to
175 feet.
The Tampa formation generally has a relatively high permeability
owing to numerous interconnecting solution cavities. It is a very produc-
tive source of artesian water in most parts of the county.
Hawthorn Formation: The Hawthorn formation, as used in this
report, includes all deposits of Miocene age that are younger than the
Tampa formation. The Hawthorn consists of gray, bluish-gray and
greenish-gray, sandy, calcareous clay interbedded with white, gray, and
tan sandy limestone and thin beds of sand and shells. The clay and lime-
stone layers contain different amounts of chert, dolomite, sand, and phos-
phorite grains and pebbles. The limestone layers are fossiliferous, in part.
The top of the Hawthorn is an irregular erosion surface that generally
ranges from about 10 feet above sea level to about 50 feet below sea level
in Manatee County. The Hawthorn is exposed along some streams and
in shallow ditches in several places in the western part of the county.
The thickness of the formation ranges from about 150 feet in the north-
eastern part of the county to more than 350 feet in the southern part,
increasing in the direction of dip of the formation.
The beds of sand and limestone yield artesian water to many domestic
and some irrigation wells. The water is generally less mineralized than
that in the Floridan aquifer. Because of the low permeability and the
thickness of the clay layers, the formation serves as a confining layer for
the water in the underlying limestone formations of the Floridan aquifer.

PLIOCENE SERIES
Deposits of Pliocene age in Manatee County were referred by Cooke
(1945, p. 208-223), to the Bone Valley formation and the Caloosahatchee
marl. The Bone Valley formation consists of sand, gravel, clay, and phos-
phorite pebbles and is supposed to be present in much of the eastern part
of the county. In well 17-11-1, sediments from the interval between five
feet above sea level and about 40 feet below sea level consist of sand and
gravel of quartz and phosphorite, with some clay and impure limestone
,near the base. These sediments, which are underlain by the Hawthorn






FLORIDA GEOLOGICAL SURVEY


formation, probably represent the Bone Valley formation. Material of
similar lithology, in a ditch north of Ellenton, was referred to the Bone
Valley formation by Cooke (1945, p. 208).
The marl, shell, and limestone beds overlying the Hawthorn forma-
tion in the western part of the county were included in the Caloosahatchee
marl by Cooke (1945, p. 223). In some places the Hawthorn formation
is overlain by a thin bed of sandy weathered material containing pebbles
of quartz, phosphorite and bone fragments. In other places it is overlain
by a thin bed of marl containing sand and gravel of quartz and phos-
phorite, marine shells, and bone fragments. These beds, which appear
to be discontinuous and are generally less than 10 feet thick, may be of
Pliocene age. The shell and limestone beds at or near the surface through-
out much of the coastal area have been previously referred to the Caloosa-
hatchee marl, but they appear to the author to be of Pleistocene age.
PLEISTOCENE SERIES
Pleistocene sediments older than the Pamlico sand consist predom-
inantly of nonfossiliferous sand which ranges in thickness from a few
feet to about 65 feet. In some places the sediments contain a layer of
hardpan a few feet beneath the surface, which confines the water beneath
it under slight artesian pressure. They are a source of water for small
irrigation and domestic supplies in the eastern part of the county.
The Pamlico terrace is underlain by sand, sandy limestone, and shells.
The beds of limestone and shells generally occur at altitudes less than 20
feet above sea level and pinch out seaward from the Pamlico shoreline.
They were probably deposited during late Pleistocene time. The bed of
shell contains a fauna very similar to that of present beach deposits;
however, Cooke (1945, p. 222-223) reports that extinct species have been
found in a bed of shells of apparently the same age in Hillsborough
(County. The Pleistocene sediments beneath the surface of the Pamlico
terrace range in thickness from less than 1 foot to about 50 feet and are
tapped by a few domestic wells.
GROUND WATER
PRINCIPLES OF OCCURRENCE
Practically all the usable water of the earth moves through the vast
circulatory system known as the hydrologic cycle. In this cycle, water
condenses from the moisture in the atmosphere and falls as rain or snow.
Then it moves over and beneath the land surface to the oceans and is
returned to the atmosphere. Actually, the cycle may be modified or
completed at any time after the water condenses from the atmosphere,
as evaporation may begin even before the water reaches the earth, and


22






REPORT OF INVESTIGATIONS No. 18


continues throughout the entire cycle whenever air undersaturated with
moisture has access to the water. Also, great quantities of water are
returned to the atmosphere by the transpiration of plants.
Subsurface water may be divided into two general classes-suspended
(vadose) water and ground water. Suspended water is the water in the
zone of aeration-the zone in which the interstices of the soil or rocks,
whether, full or not, contain water, under less than atmospheric pressure.
Ground water is the water in the zone in which all the interstices are
filled with water under pressure greater than atmospheric. This saturated
zone is the reservoir that yields water to all springs and wells.
The water in the zone of saturation may occur as (1) unconfined
ground water (under nonartesian conditions) or as (2) confined ground
water (under artesian conditions). Where the ground water is not con-
fined, and its upper surface is under atmospheric pressure and is free
to rise and fall, it is said to be under nonartesian conditions. Its upper
surface is called the water table. Where the water is confined in a per-
meable bed that is overlain by a relatively impermeable bed, its upper
surface is not free to rise and fall and it is said to be under artesian
conditions. The term "artesian" is applied to ground water that is con-
fined under sufficient pressure to rise above the top of the permeable bed
that contains it, but not necessarily above the land surface.
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. Recharge is the process of replenishment of the
aquifer with water, and areas in which it occurs are known as recharge
areas. Generally, nonartesian aquifers may receive recharge throughout
their extent, whereas artesian aquifers receive recharge only where their
confining beds are absent or somewhat permeable.
The piezometric surface of an aquifer is an imaginary surface to which
water from an artesian aquifer will rise in tightly cased wells that
penetrate the aquifer. Where the piezometric surface is above the land
surface, artesian wells will flow under natural pressure.
GROUND WATER IN FLORIDA
Ground water occurs in Florida under both nonartesian and artesian
conditions. Nonartesian conditions occur generally in the shallow deposits
of sand, gravel, shells, and limestone which constitute many aquifers of
relatively small areal extent. These deposits are the source of many
domestic water supplies throughout the State and also of public and
industrial supplies in areas where the deeper formations contain salty
water. The water in the nonartesian aquifers is supplied chiefly by
,infiltration of local rainfall.


"23






FLORIDA GEOLOGICAL SURVEY


ARTESIAN WATER
Most of Florida is underlain by a thick section of permeable limestone
formations of Eocene, Oligocene, and Miocene ages. These formations
make up an extensive artesian aquifer from which most of the large
ground-water supplies of the State are obtained. Stringfield (19386, p. 125-
13'2, 146) described the aquifer and mapped the piezometric surface in
1933 and 1934. The name "Floridan aquifer" was introduced by Parker
(1955, p. 188-189) to include "parts or all of the middle Eocene (Avon
Park and Lake City limestones), upper Eocene (Ocala limestone), Oligo-
cene (Suwannee limestone), and Miocene (Tampa limestone, and per-
meable parts of the Hawthorn formation that are in hydrologic contact
with the rest of the aquifer)." The artesian water is confined by relatively
impermeable layers in the limestone formations and by the overlying clay
beds of Miocene age which are present in most of the State, The water
in the artesian aquifer is replenished chiefly by rainfall in areas where the
confining beds are absent or sufficiently permeable to permit the passage
of substantial quantities of water from the surface into the limestone.
Piezometric Surface: The configuration of the piezometric surface in
peninsular Florida is shown by contour lines in figure 9. These contour
lines represent the height, in feet above sea level, to which water will
rise in wells that penetrate the Floridan aquifer The lines indicate the
areas in which recharge occurs and the direction of movement of the
water inl the Floridan aquifer. In areas of recharge, the piezometric surface
is relatively high. The water moves away from these areas in the direc-
tion of steepest gradient, at right angles to the contour lines, toward
areas of discharge, where the piezometric surface is relatively low. The
piezometric surface in central Florida forms an elongated dome which is
centered in northern Polk County. This dome indicates that the lake
region of Polk County is the center of a relatively large area of recharge
which probably extends into adjacent counties (Stringfield, 1936, p. 148).
The water enters the limestone formations in this area through the num-
erous sinkholes that penetrate the confining bed, or at places where the
confining bed is absent.
The small ridge on the piezometric surface in Pasco County indicates
that recharge occurs also in parts of Pasco, Hernando, and Hillsborough
counties. The basin-shaped depression in the piezometric surface in the
vicinity of Tampa Bay is the result of discharge of water from the artesian
aquifer through springs and wells.
GROUND WATER IN MANATEE COUNTY
Ground water in usable quantities occurs in all formations penetrated
by wells in Manatee County. The beds of shell and sand of Pliocene and







REPORT OF INVESTIGATIONS No. 18 25

.. .. 682' 0I' 0.*


i__G 1E 0 R I A GI >
0 ^'oes A tN .'[ 4 / 9 J" NAS S A
Io t A ILON I' 50 .
-6LEM1 \ .. ..... ... .. \ }%- /e ....
MA I- \' 11 I 0 I'SON \
iAN L.' ANNtI A 1
Lion y WA LLA A lld1 A


0 \h-:-_- l, 1 0 vi \ C0


---1 (
SI < -, oRANKLI 90 0 .
Ln LoVaY sv MARION "L-









e t p a na on o i
01 I e 1 0\0
4 /1 !O LS N I A R









I HIGHLANDS 'yj+




L E HENRY PALM OEACH


Or\, ,_o \ /0"'._ ....._..L
1 Rnins i n t i l Ot WARD
0 \J L 80 0 1' -OSCEOLAN 9 21






EXPLA ANATIEN P L




Contour lns represent approximately the height, AE
In feet above mean sea level, to which water \
would have risen in tightly cased wells that
penetrated the principal artesian aquifer in
1949. --.


Approximate 8so0le W '.Jo

Figure 9I Map of the Florida Peninsula showing the piezoetric surface.
Figur 9. Mp ofthe ForidaPenisula howin thepieorntfosurlfae






FLORIDA GEOLOGICAL SURVEY


Pleistocene age yield water to many domestic wells. The water in these
deposits is replenished by local rainfall. In some places it is confined
under slight artesian head by layers of hardpan, clay, or limestone.
Reports by drillers indicate that most of the shallow wells in the county
penetrate at least one thin bed of clay or limestone that confines the
underlying water under artesian pressure, although the pressure is not
generally sufficient to produce a flowing well.
ARTESIAN WATER
In Manatee County, as in most of the state, the Floridan aquifer is the
priticipal artesian aquifer. Probably most of the water in the Floridan
aquifer in Manatee County comes from rainfall that infiltrates into the
aquifer in the recharge area of Polk County. From there it moves south-
westward into Manatee County, as indicated by the configuration of the
contours in figure 9. However, some recharge may occur in the north-
easternt part of Manatee County, where the piezometric surface is con-
siderably lower than the water table and ground water from the non-
artesian aquifer may percolate through the confining beds into the
Floridatn aquifer.
The Avon Park limestone and the Ocala group are penetrated by a
few wells in the county and are probably capable of yielding large
quantities of water, but they have not been used extensively because the
Suwannee limestone and Tampa formation yield enough water to supply
most wells. The water in the Suwannee limestone and the Tampa forma-
tion occurs in permeable zones that are generally separated by layers
of low permeability which retard the vertical movement of water. These
layers are discontinuous and are not completely impermeable, however;
hence, water may move from one to another permeable zone.
The Hawthorn formation, consisting predominantly of clay and marl,
serves ais a confining bed for the water in the underlying limestone forma-
tions. Thin beds of sand, shells, and limestone within the formation, which
are generally separated by relatively thick beds of clay, are the source of
many domestic and small irrigation supplies. These permeable beds
within the Hawthorn are generally separated from the Floridan aquifer
by layers of clay or marl.
The piezometric surface of the Hawthorn formation has not been
mapped; thus, the area of recharge is not known. Some recharge, at least
to the upper part, probably occurs in eastern Manatee County. The
lower part of the Hawthorn probably receives considerable recharge
from upward leakage of water from the Floridan aquifer, as the artesian
pressure in the Hawthorn is considerably less than that in the Floridan
aquifer.







REPORT OF INVESTIGATIONS No. 18


27


Current-meter Exploration: In order to determine the depth, thick-
ness, and relative productivity of the permeable zones in the limestone
formations, explorations were made in several selected wells with a deep-
well current meter, a device for measuring the velocity of the flow of
water through a well bore. The results of the current-meter traverses,
and other data pertaining to these wells, are shown graphically in fig-
ures 10-16. The velocities are expressed in revolutions per minute (rpm)
of the current meter. Actual flow rates, which are a function of velocity
and cross-sectional area, cannot be computed accurately, as the diameter
of the uncased part of the well bore is not uniform.
The results of a current-meter traverse in well 27-28-2 are shown
graphically in figure 10, which includes also an electric log of the forma-
tions and a diagram showing the construction of the well. The well was
Z SELF-POTENIIAL HELAlIVE RESISTIVITY VELOCITY
AGE 9 I0 my 25 ohms (rpm of current meter)
toL .... 50 0 0n Im


100




200




300




400




500


600


Figure 10. Graphs showing data from well 27-28-2, seven miles southeast of
Bradenton,







28 FLORIDA GEOLOGICAL SURVEY

flowing at the rate of about 450 gpm while the traverse was being made.
The velocities show that little or no water entered the well below a depth
of 615 feet. Some water entered the well between depths of 615 and 570
feet, but most of the total yield of the well was obtained from the interval
between 560 and 540 feet. The permeable zones of the Tampa formation
above 450 feet yielded some water. The large variations in velocity in
the uncased part of the well probably represent differences in size of
the well bore. The higher velocities in the cased part of the well indicate
that the diameter of the uncased part is considerably larger than eight
inches.
The velocities in well 28-29-3 (fig. 11) were determined when the
well was flowing at the rate of about 60 gpm. They indicate that the
Suwannee limestone yielded no water below a depth of 605 feet and that
most of the water from this formation was obtained from the intervals

E LF PO LNIIHAL RLLAtIVE hESIslivIl Y VELOCIIY
^G 10 my 25 Ohms (rpm of current meler)
-- 0 50 100
Pliocene .
0 and




o100 o----- t 00



I o.
.t

_200 _200


0
L a.J, o-







400. __400



500 I -- 500


OU W

S400 -- I. -- --- 600


Figure 11. Graphs showing data from well 28-29-8, six miles southeast of Bradonton.






SELF- POTENTIAL RELATIVE RESISTIVITY VELOCITY CHLORIDE CONTENT TEMPERATURE
AGE 10 my 25otms (rpm of current meter) (parts per million) (degrees Faireeit)
0_-" -o 50 100 500 100 1.500 2000 2,500 0 81 82




oo 0



100 W----- -- ------------ ^ ---------- ---- X




us a



O a ________ jar' _____ / o 8
3f 0





a 00

















soc = ----= ----- soo
Figure 12. Graphs showing data from well 28-41-4, near Cortez.











IN FEET


BELOW MEAN SEA LEVEL


-I

C'
C'













0
to
0





0
0
Ca
0



0
0


DEPTH,


o oj ro o
6 o o o a
0 0 0 0 0
0 0 0 0


0
.5'

3


b.,








CA


rri
I-
0
C)
-4


I IcpO
C,
C
.5'
-q


03



U,






REPORT OF INVESTIGATIONS No, 18 31

between depths of 605 and 585 feet and 525 and 505 feet. Most of
the total yield of the well was obtained from the Tampa formation,
between depths of 445 and 405 feet and 365 and 340 feet. The variations
in velocity between depths of 335 and 200 feet are due to differences
in size of the well bore, and they reflect the hard and soft layers in the
Tampa and Hawthorn formations. The higher velocities in the 6-inch
casing indicate that the diameter of the uncased part of the well is more
than six inches.
The velocities in well 28-41-4 were determined when the well was
flowing at the rate of about 60 gpm. They are shown in figure 12. Most
of the water from the Suwannee limestone entered between 590 and 520
feet. Some water was obtained from the Tampa formation between
depths of 480 and 470 feet, but most of the water from this formation
entered the well between 420 and 365 feet. The productive zones



SELF- POTENTIAL RELATIVE RESISTIVITY VELOCITY
Lt g 10 my 25ohms (rpm of current motor)

o oLI EN .........
PLIO NE .


100- 100



200, 200



300 02300

S0 400
ILt S ^^

0 --- --- 1T^'^ 4^rAo


Figure 14. Graphs showing data from well 80-28-1, seven miles cast of Bradenton.










SELF POTENTIAL
10 mv


RELATIVE RESISTIViTY
25ohms


VELOCITY


CHLORIDE CONTE14T
(Darts per mallac)


200






300





400 ><


Figure 15. Graphs showing data from well 38-32-5, five miles northeast of Terra
Ceia.


AGE 9






REPORT OF INVESTIGATIONS No. 18


indicated by the velocities correlate generally with changes in chloride
content and temperature, as shown in the figure.
Well 29-29-4 was flowing at an estimated rate of 110 gpm when the
velocity measurements shown in figure 18 were made. The velocities
indicate that most of the total yield was obtained from the Tampa for-
mation, in the interval between depths of 450 and 860 feet. The large
variations in velocity probably represent differences in the diameter of
the well bore. The decrease in velocity above a depth of 50 feet may
represent a loss of water to a permeable zone in the Hawthorn formation.
Well 80-28-1 was flowing an an estimated rate of 500 gpm when the
velocity measurements shown in figure 14 were made. The velocities indi-
cate that no water entered the well below a depth of 500 feet. Some
water entered the well between depths of 500 and 470 feet and a large
quantity entered between 465 and 430 feet. Most of the water came from
the Tampa formation in the interval between 375 and 350 feet, but some
may have entered the well from the upper part of the formation, between
240 and 230 feet. The large variations in velocity above a depth of 850
feet probably represent differences in the diameter of the well bore.
The velocities in well 88-32-5 were measured when the well was
flowing at the rate of about 400 gpm. They are shown in figure 15. The
velocities indicate that no water entered the well below a depth of 450
feet. A large part of the total yield was obtained from the upper part of
the Suwannee limestone between depths of 450 and 420 feet. Some water
probably entered the well from the Tampa formation between depths
of 880 and 860 feet, but most of the water from this formation entered
between 350 and 825 feet. The decrease in velocity above a depth of
225 feet represents a difference in the size of the well bore, as shown in
the diagram.
Artesian Head: Water-level measurements were made in many wells
during the investigation, to determine the altitude of the artesian pres-
sure head in different parts of the county and in the different formations.
These measurements, published separately as Florida Geological Survey
Information Circular No. 19, show that the water in the Tampa formation
and the water in the Suwannee limestone are under approximately the
same artesian pressure head; however, small differences may occur locally
during periods of heavy withdrawals. The head in the Hawthorn forma-
tion is generally several feet lower than the head in these underlying
formations of the Floridan aquifer.
Because the head in the Floridan aquifer is higher than that in the
Hawthorn formation, water from it moves up through partially cased
wells and flows out into the permeable beds of the Hawthorn formation.
This is illustrated by the graph in figure 16 which shows the results of


88







FLORIDA GEOLOGICAL SURVEY


a current-meter traverse in well 29-37-10. This well does not flow at
the surface, and at the time the traverse was made the water level stood
about eight feet below the top of the casing. Water entered the well from
the Tampa formation and the top of the Suwannee limestone in the inter-
val between depths of 450 and 325 feet, moved up the well and out into
the Hawthorn formation above the top of the 6-inch casing, in the
interval between depths of 70 to 60 feet.
Fluctuations of water level in artesian wells range from a fraction
of a foot to several feet and are caused by one or several factors. The
larger fluctuations are generally due to daily and seasonal variations in
withdrawals of water from wells or to recharge from rainfall. Minor
fluctuations are caused by such factors as ocean tides, atmospheric-
pressure changes, winds, earthquakes, and passing trains. These factors
and their effects on water levels are discussed in detail in a paper by
Parker and Stringfield (1950).
z SELF- POTENTIAL RELATIVE RESISTIVITY VELOCITY
AGE :o 10 mv 25ohms (rpm of current meter)
u. 0 20

0 Plestocend --
Phliocene
O-- O


100 100

0
j U

J z

J z H



o ----- 300









40
S400- -- -- ------ --- 400




500 .----500

0 1


600 -------*-- -- : 600
Figure 16. Graphs showing data from well 29-37-10, four miles west of Bradenton.






REPORT OF INVESTIGATIONS No. 18


Records from continuous recording gages installed on four wells and
water-level measurements made periodically in more than 30 wells pro-
vide information on the fluctuations and progressive trends of the
artesian pressure head in Manatee County. These records show that the
largest fluctuations were caused by the variations in daily and seasonal
withdrawals of water from wells; however, observable fluctuations were
caused by earthquakes, changes in barometric pressure, and ocean tides.
Figures 17 and 18 show hydrographs prepared from records of the con-
tinuous recording gages, and figures 1.9-23 show hydrographs of 17 of
the wells in which water levels were measured periodically. Water-level
measurements in other wells are listed in table 6.
Measurements of water level in well 26-18-1 were begun in 1941. A
continuous recording gage was installed in February 1945 and is still
in operation. The hydrograph of this well (fig. 17) shows seasonal fluc-
tuations and the general trend of artesian pressure head from June 1941
to December 1956. The seasonal use of artesian water in the area is
indicated by a decline in head during the periods of least rainfall when
large quantities of water were being used for irrigation. The higher head
during periods of greater rainfall may be due partly to recharge, but it
is due principally to a decrease in withdrawal. Seasonal fluctuations of
several feet occurred during the period from 1941 to 1948, but there was
apparently no progressive change in head. As shown by the hydrograph,
the magnitude of the seasonal fluctuations has increased and the head has
declined progressively since 1948, indicating a progressive increase in
both seasonal and perennial use of water. The water level in this well
reached a record low of 82.17 feet above sea level on April 28, 1956.
The hydrographs in figures 19-23 show the effects of seasonal use of
water from 1951 through 1955. Most of them show a slight progressive
decline in artesian pressure head during this period. The lowest water
levels were recorded in April and May 1956.
Earthquake waves passing through the earth's crust cause a rela-
tively rapid expansion and contraction of artesian aquifers and force
the water levels in wells to rise and fall. The effects of earthquakes on
the water level in well 26-18-1 are shown on the hydrographs in figure
24, which were traced from charts of the automatic 'recording gage.
The destructive earthquake that occurred in the Dominican Republic
on August 4, 1946, caused a maximum water-level fluctuation of 1.15
feet, and an after shock of this earthquake on August 8, 1946, caused
a maximum fluctuation of 0.17 foot. A severe earthquake in north-
western Costa Rica on October 5, 1950, caused a maximum fluctuation
of 1.55 feet.
The daily changes in atmospheric pressure cause minor fluctuations


35











1 -? -< ,

S- .... .-- t . ... -" -5-"- -6
5- 3-- ---.----- --,- -- -- ---



S -----------'- -- ---- -- -------------------^ -- ----- --- ....- .T-o- ---...."--------. _- ,


3-1' I
SWLL 26--40



-J '_18 MILES SOUTHEAST OF BRADENTON 35

^--------------______ --_______--- -.---------.- -.-.--- ---34-
-- ______ ___ -- 33

32 9 95 .9 9C 95 52 953 95 955 056 32



24 -2---1--------------- --- 24



+ 1__ '
2 L6--------- ------------- --H---- -|-- -------4------------------- .2
3 3 3


Figure 17. Hydrograph of well 26-18-1 and rainfall at Bradenton.


0


0
0
0
C,
0

C-,

Lu,
'4







REPORT OF INVESTIGATIONS No. 18


21




I


Figure 18. Hydrographs of wells 27-36-3, 28-31-1, and 31-34-6.


23~"- I" TT''~llll-l-IT- l" l b~1'"'-s'


21







WELL 27-36-3, 4 MILES SOUTHWEST OF BRADENTON











25



9-- ------- --- ----------i-- -- ------- ----|------------i---------------i--





SWell 28-31-1, 4 MILES SOUTHEAST OF BRADENTON






20 --



2 .---------- i -----I-----..----- --- ---.-



14
WELL 31-34-6, I MILE NORTHWEST OF PALMETTO

1 1952 1953 1954 1955 1956







FLORIDA GEOLOGICAL SURVEY


44 .....

43 -- -- -
WELL 17-I*I1, 4 MILES SOUTHWEST OF MYAKKA CITY
42


26 _ _


24 -
22 --..- -...---.--.



20 -------------
WELL 24-30-1, 4 MILES SOUTHEAST OF TALLAVAST
i n .. i. .1.. I I .-


30 .-.. .. I ....-- /.


WELL 28- 23-1, 12 MILES EAST OF BRADENTON
2 6 I . .. .. ..I. .

22
WELL 29-37-7, 4 MILES WEST OF BRADENTON
20 ... ____ ______________

14 -

I1 5 19521953 -1 5419--55

1951 1952 1953 1954 1955


17-11-1, 24-30-1, 26-41-2, 28-23-1, and 29-37-7.


Li_ L~L__I


/0'**'A


I


Figure? 19. HTydrogaphs of wells '








REPORT OF INVESTIGATIONS No. 18


w
LL


39


8000
CHLORIDE CONTENT OF WATER


4000
WELL 28-41-4, NEAR CORTEZ

WATER LEVEL

12-------


Figure 20. Graphs showing relation between water levels and chloride content of
water in wells 23-38-3, 28-41-4, and 29-40-10.








40 FLORIDA GEOLOGICAL SURVEY
i

-
WATER LEVEI










300-N

250-- --


200 -

150, ------ ------ ------^ -
_____ 1252 953


24
WATER LEVEL




10 .-- --- ---. -- ___


Figure 21. Graphs showing relation between water levels and chloride content of
water in wells 27-34-1, 27-38-7, and 27-41-1.








REPORT OF INVESTIGATIONS NO. 18


1,000

800


300
CHLORIDE CONTENT OF WATER
250 - j-^


_- I


i ., I I_


Figure 22. Graphs showing relation between water levels and chloride content of
water in wells 29-42-3, 831-37-12, and 33-35-4.


41


WELL 31-37-12, 2 MILES NORTH OF PALMA SOLA<


WATER LtVEL



-- --- -


200
24

22

20

18

16


--








FLORIDA GEOLOGICAL SURVEY


Figure 23. Graphs showing relation between water levels and chloride content of
water in wells 30-39-11, 31-43.3, and 31-44-3.


42


vi



4t


W
w
A
1x








042







REPORT OF INVESTIGATIONS No. 18


43.0


42.5



42.0


41.5


41.0


46.01


45.5


45.0-


4.. 5' 6 7 8 9 0o
OCTOBER 195046




F*-"Possage of hurricane center 40 miles NNW
Poyg vof well



Fluctuations caused by normal
atmospheric- pressure changes

OCTOBER 1946 j


Effects of earthquakes and changes in barometric pressure on the water
level in well 26-18-1, 12 miles northwest of Myakka City.


,-Maximum fluctuation: 1.15 feet

Maximum fluctuation: 0.17 foot.






,... DOMINICAN REPUBLIC EARTHQUAKES


3 4 5 6 7 8' 9
AU(UST 1946


R.


S 1 1 II
I NORTHWESTERN COSTA RICA EARTHQUAKE


---Maximum fluctuatitL : 1.52 feet


4'


Figure 24.


I-


r


- ----


a"TV.


4W


A e






FLORIDA GEOLOGICAL SURVEY


of water levels in most artesian wells. These fluctuations, however, are
often masked by larger fluctuations resulting from local pumping, ocean
tides, or other causes. The effects of atmospheric-pressure changes on
the water level in well 26-18-1, which is not affected by pumping or
ocean tides, are revealed by the hydrographs in figure 24. Periods of
high barometric pressure occur about noon and midnight and are shown
by low water levels at these times. The periods of low barometric,
pressure in the early morning and late afternoon are represented by
high water levels on the hydrographs. The magnitude of the fluctua-
tions in this well is generally less than 0.1 foot but may be considerably
greater when barometric pressure changes are greater than normal.
As shown in figure 24, the water level rose 0.45 foot on October 7, 1946,
when the center of a hurricane passed about 40 miles west of the well
at approximately 11:80 p.m. The lowest recorded barometric pressure
at Sarasota was 29.26 inches, and at Cortez it was 28.95 inches, or about
one inch lower than normal.
Piezometric Surface: The contours on the map in figure 25 show the
configuration of the piezometric surface of the Floridan aquifer in
Manatee County in September 1954. The piezometric surface was more
than 65 feet above sea level in the northeast corner of the county and
sloped westward to about 20 feet above sea level along the coast, in-
dicating a general westward movement of water. East of the 80-foot
contour, the piezometric surface has a fairly uniform gradient of about
1% feet per mile. The uniformity of the gradient indicates that no large
quantity of water was gained or lost by the aquifer in this area. West
of the 30-foot contour, the gradient is less than one foot per mile. The
configuration of the 20-foot and 22-foot contour lines indicates that
appreciable discharge is occurring near Palma Sola and Palmetto. As
the quantity of water being withdrawn from wells at the time the
water-level measurements were made was small, the low-pressure
trough around Palma Sola shown by the 20-foot and 22-foot contour
lines, is probably due in part to a movement of water from the Floridan
aquifer into the younger formations through unused irrigation wells.
Figure 26 shows the configuration of the piezometric surface in June
1955, during an extended period of dry weather when large quantities
of water were being withdrawn from irrigation wells. The altitude of
the piezometric surface ranged from about 60 feet in the northeast
corner of the county to less than 13 feet in the vicinity of Palma Sola.
A comparison of figures 25 and 26 shows that throughout the county
the piezometric surface was about five feet lower in June than in Sep-
tember; at some places in the western part of the county it was about
10 feet lower. The configuration of the contour lines in the coastal area







S- S C C Cuv
45 < SW82*3 252-V


j IN


I- -A ___ ___ __I: I ~~


;77-T7TT777~T--vTF1TT-rn-


Tifi/i


'V.


,i/ p *J-ff


i~~~/: /


7,-V .11111 LV1~'\ I~~Y


.1 .-i ri -c


dc 1 'I ; l


!I


ly~


')%is~~l: ~I~~~L~ P-~ r:~ (~. Li


INA IF gfigiefflumb. AL- I % I I ~ I %It % % AIL
i -7 -i -1-7roAR.Mbe
'gr
N-mt-.-s
---LA

MAC
*owe cc

IL


S~ ~ NAXJJJ~TSO.


I 'I\ I


25-


/I~" L- ~ IfiLRN


I VV-X-J I


e- 2%
S&34SC0a C C v *


k~Li~A~YA\ 'NiV\ \ Nr1~J


I> *~


nflowpnq well shower; well flurr.er
cnd ciliut~de of oiezormetryc slurftce

Flowing well showing well i,'.wiber cand
cltisude of prezer-e~ruc surface


WvC *wth recorder 7t1wwmg we-Cl number
an-d al:Itude a'of pezonetr#C Surface

fls,cvrg approxarnoie altitude cf bie
piezomoe'ric surface in feet cbove oieacn
see levei


__ IV \~XiiW


9 .- .o


Figure 25. Map of Manatee County showing the piezometric surface in September 1954.


z".


3


i ~-~Ljrr-C~s~pr?--;T--T~-iC~-l--~T-Ti-m


, L


-1.- !-.74 %.L 1 i I F -.4 4 i!7


-r- -P


% -- -1--e _


- [ -1i- 105 i P i i --t w t 0 1


I ld--, c e i 1 1 1 1 k -k = -X -4 4 4 ;-4


. 1~ ~ ~ ~ -1,i i 'f --t tb


U9 --- --- -


-M-


i 3F


i -c t t


vT-Ad~,L-


--


L~-Y- -~_ -- --~e-


1 :9 ; ._ _


, ---


I 14 -l


1( --- % t i -ll. N N-* I' tI*


l


. .-- 1 ,ICZ l


I


A\ A- i\ \










27 -7 -














I. l. 4 ''"---- -





EXPLANAT ONA
2 0' .P. 5 r';"

Nonflowing well showing well number Well with recorder show- g well number .__
and altitude of peezometric surface and altitude of piezomrnetric surface 20 '
*2T



I l--' --02
Flowing well showing well number and Lne showing approximate altitude of the
altitude of piezometric surface piezomrnetric surface in feet above mean\'


s i ev el,




Figure 26. Map of Manatee County showing the piezometric surface in June 1955. .






REPORT OF INVESTIGATIONS No. 18


in figure 26 shows that the low-pressure trough in the Palmetto-Palma
Sola area had expanded and deepened as a result of the increased
withdrawals of water from irrigation, industrial, public supply, and
domestic wells. The depression shown by the 20-foot contour line, in
the northern part of the coastal area, was caused by the combined
drawdowns of a large number of irrigation wells.
Depth to Water Level Below Land Surface: Figure 27 shows the
areas of artesian flow and the approximate depth to water, below land
surface, in wells that penetrate the Floridan aquifer. It is based on the
piezometric surface in June 1955 (fig. 26).
The areas of artesian flow are along the coast and in the southeastern
part of the county, and they extend several miles upstream along the
valleys of the major streams. There are several isolated areas within
the areas of artesian flow where the land surface is relatively high and
wells will not flow.
In most of the county water levels are less than 25 feet below the
land surface but in the northeastern part of the county they range in
depth from 50 to more than 75 feet.
Temperature: The temperature of the earth's crust increases with
depth at the rate of about 1lF for each 50 to 100 feet. The tempera-
ture of ground water generally increases with depth at approximately
the same rate.
Measurements of the temperature of water from many wells were
made during the investigation. The temperature of water in formations
less than 100 feet deep is generally between 740 and 750F, and that
of water from the Hawthorn formation is between 750 and 77.5F.
The temperature of water from the Tampa formation generally ranges
from 77.50 to 790F, according to the depth of the principal producing
zones and the proportion of the total yield of the well that is obtained
from each zone. Water from wells that penetrate the Suwannee lime-
stone and older formations ranges in temperature from about 79 to
more than 84F, according to the amounts of water obtained from the
various producing zones in both the Tampa formation and the Suwan-
nee limestone as well as in the older formations. Water samples taken
with a deep-well sampler indicates that the temperature of the water
in the Suwannee is 810 to 82F (fig. 12).
The temperature of the water in the Hawthorn and older forma-
tions generally increases in the direction of dip, because of the in-
creased depth of the various producing zones.


47









-.* *S owSwmeco .O@W%


or





35


As3c
Figure 27. Map of Manatee County showing the area of artesian flow and the depth .o....
to water in June 1955.


os' e


-9--I


















.. hi EXPLANATO10

AREA OF C
ARTESIAN FLOW
WATER LEVEL, IN FEET 1
BELOW LAND SURFACE 2 \



-as


E3*.s* s- -:N
b. t I -. J ,


,is


V,



0n


r






REPORT OF INVESTIGATIONS No. 18


USE OF WATER
Ground water is the source of practically all irrigation, industrial
public, and domestic water supplies in Manatee County except the
Bradenton municipal supply, which is obtained from the Braden River.
The use of water from that municipal supply averages about 3 million
gallons a day; however, numerous private wells throughout the city
furnish water for lawn irrigation, air conditioning, and other uses.
The individual records of 865 wells are published as Florida Geo-
logical Survey Information Circular No. 19 and their locations are
shown in plate 1 and figure 2. The wells that penetrate the Floridan
aquifer are generally between 350 and 600 feet deep. They range from
3 to 12 inches in diameter, but most of them are 6 to 10 inches in
diameter. They are cased to depths ranging from about 25 to more
than 100 feet. In addition to the surface casing, some wells are lined
with an inner casing to prevent the caving of sand from the Hawthorn
and Tampa formations. The wells generally yield several hundred
gallons per minute, but the yields differ according to the permeability
of the aquifer, the diameter of the well bore, and the thickness of the
aquifer that is penetrated by the well.
Shallow wells range from about 25 to more than 200 feet in depth
and from 19 to 6 inches in diameter. Most domestic wells are two
inches in diameter and yield about 30 to 75 gpm.
There is no practical method for determining accurately the average
daily use of water in the county, because of the large variations in daily
and seasonal withdrawals, and the fact that accurate records of with-
drawal are available for only a few of the many wells. It is roughly
estimated that the average daily use of water in Manatee County is in
the range of 15 to 20 million gallons.

QUANTITATIVE STUDIES
The withdrawal of water from an aquifer creates a depression in
the water table or piezometric surface around the point of withdrawal.
This depression generally has the approximate form of an inverted cone
and is referred to as the cone of depression. The amount by which the
water surface is lowered at any given point within this cone is known
as the drawdown. The size, shape, and rate of growth of the cone of
depression depend on several factors: (1) the rate of pumping, (2) the
water-transmitting and storage capacities of the aquifer, (3) the in-
crease in recharge resulting from the lowering of the water surface,
and (4) the decrease in natural discharge due to the lowering of that
surface. The yield of the Floridan aquifer in Manatee County is limited
by the extent to which the piezometric surface can be lowered without






FLORIDA GEOLOGICAL SURVEY


impairing the quality of the water or making the cost of obtaining it
prohibitive.
The principal hydrologic properties of an aquifer are its capacities
to transmit and to store water, for all aquifers serve as both conduits
and reservoirs. An artesian aquifer functions primarily as a conduit,
transmitting water from places of recharge to places of discharge; how-
ever, it is also capable of storing or releasing water, by expansion and
compression.
A measure of the capacity of an aquifer to transmit water is the
coefficient of transmissibility. In customary units, it is the quantity of
water, in gallons per day (gpd) at the prevailing temperature of the
water, that will flow through a vertical section of the aquifer one foot
wide and extending the full saturated height, under a unit hydraulic
gradient. The coefficient of storage is a measure of the capacity of an
aquifer to store water, and is defined as the volume of water it releases
from or takes into storage per unit surface area of the aquifer per unit
change in head normal to that surface.
Pumping Test: A pumping test was made in August 1955 to deter-
mine the transmissibility and storage coefficients of the Floridan aquifer
at one location in Manatee County. Well 34-30-1 was pumped at the
rate of 1,000 gpm for a period of 123.5 hours, beginning at 11 a. m. on
August 22 and ending at 2:30 p. m. on August 27. Water levels were
measured periodically in wells 34-30-2, 34-30-3, and 34-30-4 (fig. 28)
throughout the period of pumping, to determine the rates and magni-
tudes of drawdown at different distances from the pumped well. After

N



EXPLANATION
Pumped well
0
Observatlon well
0 5 ,O0 FEET
34-30-3



34-30- 2 34-30-I


Figure 28. Sketch of pumping-test site, showing location of pumped well in relation
to observation wells.















WELL 34-30-4, 7 MILES NORTHEAST OF BRADENTON ..-- ..
**** --"... ... .. .



4... ................. ...____.____



WELL 34-30-3, 7 MILES NORTHEAST OF BRADENTON .
"L 3 7 M N O B .








22_ 23 24 _25 26 2729


' .. .-AUGUST, 1955-
i 22, 2> 3 24 I 2S3 2 6e i 27 2 8t 29 o
___________________________________________________AUGUST. ,19SB__________________________________


Figure 29. Graphs


showing drawdown and recovery
wells during pumping tes


of water levels in observation


PCi
0


0




C02

z






FLORIDA GEOLOGICAL SURVEY


pumping stopped, measurement of water levels in the observation wells
was continued for about 72 hours. Hydrographs prepared from these
water-level measurements are shown in figure 29.
The Theis graphical method (Wenzel, 1942, p. 87-89) was used to
compute the transmissibility and storage coefficients from the draw-
downs in the observation wells. This method relates the drawdowns
in the vicinity of a discharging well to the rate and duration of dis-
charge and is based on several simplifying assumptions, including the
following: (1) the aquifer is of infinite areal extent and is uniform
in thickness, (2) the aquifer is homogeneous and transmits water with
equal facility in all directions, (3) the discharge well penetrates the
entire thickness of the aquifer, (4) there is no recharge to the aquifer
in the area of influence of the discharging well, and (5) the aquifer is
losing water through only the discharging well.
As shown in figures 30 and 31, the data for each of the observation
wells plotted as a separate curve and the upper part of each curve fell
below the type curve. These deviations indicate that the aquifer does
not closely conform to one or more of the conditions assumed in the
This e(llation. The downward deviation of the data curves from the
type curve during the latter part of the test is an indication that the
a(quifer was receiving recharge probably from the overlying Haw-
thorn formation. The data curves were analyzed by using a leaky-
aquifer type curve (unpublished) developed by H. H. Cooper, Jr., of
the U. S. Geological Survey, Tallahassee. The curve for well 84-30-3
best fitted the leaky-aquifer type curve. The results obtained by using
data for well 84-30-3, therefore, are believed to be most representative
of the Floridan aquifer in the area of the pumping test.
The coefficients of transmissibility and storage computed by match-
ing the observed-data curves against the type curves are as follows:
Coellicient of Transmissibilily Cocificient of Storage
Well Drawdown Recovery Drawdown Recovery
31-30-3 100,000 96,000 l.lx10- 1.4xl0-'
314-30-4 140,000 140,000 4.3x 10- 4.3x 10-
34-30-2 460,000 480,000 1.0x 10-" 8.7x10-4
The data for well 34-30-3 were also analyzed by a method devised
by Cooper and Jacob (1946, p. 526-534), which gave a transmissibility
of 100,000 gpd per foot and a storage coefficient of 1.lx10-' (fig. 32).
Theoretical Drawdowns: The results of the pumping test indicate
that the transmissibility coefficient of the Floridan aquifer near the test
site is about 100,000 gpd per foot and the storage coefficient is about
0.00014. The coefficients of transmissibility and storage may differ con-
siderably from place to place, and because of this, it is not practicable to


52









,3 2 3 S 365 7


39 2 3 4 S 6 ?6 91 2

-: ;."L .. 1 : i [ : i: i .-I .ki-.I .'- *. ;|l;.i. .:.


3 4 S


1 PONT 7


S7 s9


.ti:L .-!_ -c L t


l.; 4 1 :2 I '.,.:II:i.!.I! ;F.T.Ti .j: LL.::... Fi' : j Ii +


I* I 7 3: 9.1-- 97=


.___.-_: _____.. _...:... ..:... :.... .. . .._____'"___ _'__'_ .-.'7 i


:1:74 _____ nfl-L


L4Tf- i "


)-- .

o n
ti

2a
z"






o-
0.
7.

S
4.




2




0.01


.~~~~ t.1.. '1 iii II: ~~


S* "-- ---- -


S. : .;.: ....:.. .,. .. ... ,.aC.i L1 ::KI.: L.4'-V1 .I~4


I.=.. :r: t :
,.'-"'-'. *4.:


T I tC ; i i ; l .I i i i


-t~~~o..*O 6:,- ~ --- -9~ V'?Ir


L.s r"- ki*** ih : Iw,


I Ia l 4 A


;~P4TI~tJ


:- .::; .-; ; :::I- -t .-: .. :: .. :.. f : ::-. 4 -


-tLitiJ .W'~


A. ;:*I


it -
4yin!7.

iu:uihj:W


3 4 5 7 i .-


Ls *---sr *** !E.^**^ ***s


F i ".'- ".i ".-.&I -Lt -I


3 45 6 7 s i
t/rt (days/ft!)


. ..: ::::::.::;::.:... ... .


~i~i~ii~;Li~i~ii~ie~iiii-ii-t~t iiiliijii:ililii:i~t~


I:7.


.: .. ; :..... .


n. -:- if iIi K ...:



li.?!!!!4- 1 pt!
rumlitil~~~~~~~- M--_... ....... .. ..


3 4 S6 7 8


EXPLANATION

0 = 1,000 gpm
W(u) = 1.0
u = 0.1
114.6 0QWu)
T= s

1.87 r'
o
Well 34-30-3
s = 1.13 feet t/r'= 23 x I0-
T =100,000
S=LI x lO"4

Well 34-30-4
s=0.8 foot t/r =5.6 x 10"
T= 140,000
S=4.3xl0
0
Well 34-30-2
s=025 foot$ t/r== 4.1x 1o
T = 460,000
S =1.0 910O


2 3 4 167


Figure 30. Logarithmic plot of drawdowns in observation wells versus t/r'.


-=- ... -


4 5 6 7


0

i.

7 0
6 ^
5 -





I Z
3






, 9

$ 1Z
I Z


....i...L..ic


- i~ii~~: :~lii~!. l~ ~~ I MI


I i ;.L r .- : '. -


. . . .


'i-S;":;-


,-T


i i r 1 )'~) iirrl: ~1 "'~;-C~" t~


' ~'


---


------


.4


a


L


I I i I b -- --- k,, 1- Lii tL 1 IF '


-- --


T


.. '.


r~ irr;;rrl i i (i1l !11(1111111:111111 11111( 1 ~) I it Lt )


iii~iii~ri-i~tii~L~~


- 1 t'l 1.


i i-h. SH.M, il i :i 1 L-=m =f--


'


--- -- -~~-- -- -- -


, I '


.


: *-l I I. -. 1- I*. A I.+ii. .4 .-*.i


~if-iii~iit'i:~-~~~~''-~:~~~"::'~'~t~ii


4 .$ S 1*f1


3 4


7 9.1


I I. .. .1 .1 _


; t


* :


71


:-r.: L


I '.+ .- : ," !. I


I ':T -."- I: : ,.


7-


i :i I 8: i i. I i i i :: i i i


-


L~ii iT~Ii~i::i~~ii i Ili~i:l! n-~,~~ l~-i~~ii~iiit'il'~. i~ii~~~i~~j iii~~_~;~ i~;:~;~.i~ i~~:tImest~t


ID]-7 7!


,1 i '.'*.T l '- I


r: :t;i;n-.i;:;.


I


*S ~S : ; i : ::; :.*:::: ;;::;.* I.;;*:'l .l) .:::=f -^


.1


F-?. .


--


f! !iit*[ \t\ i';l- t..


~~1 i fi I S.i i i iiirii~siiii:ii:i::riirit:i'::i::~'~f~ i


r-,;


0 Hiim MEM ME


2 3 4 6 7


t












t/e' (days/ft.')


3 5t


Figure 31. Logarithmic plot of recoveries in observation wells versus t/r2.


0





0


C,





t4
'.4


2 i 4 5 76 81 3...


4 5* ,i6-0


7 9 9 ib-6
















IJ
Ld










5

6-

L



0.001
5-




6- OI


Time since


Figure 32. Semilog plot


pumping stopped (days)


of recovery versus t for well 34-30-3, seven miles northeast
of Bradenton.


0.01 0.1


0

Z





CO

0

oz


1.0






FLORIDA GEOLOGICAL SURVEY


predict drawdowns in one place on the basis of aquifer properties deter-
mined in some other place. However, in order to illustrate how water
levels are affected in the vicinity of a pumping well, figure 33 was con-
structed. This figure shows theoretical drawdowns in the vicinity of a
well pumping at the rate of 1,000 gpm from an aquifer having a trans-
missibility coefficient of 100,000 gpd per foot and a storage coefficient
of 0.00014.

QUALITY OF WATER
The water that falls on the earth's surface as rain or snow is practi-
cally free of dissolved mineral matter except for small quantities of
atmospheric gases, smoke and dust. Therefore, the mineral constituents
and degree of mineralization of ground water depend generally upon the
composition and solubility of the soil and rocks through which
the water passes, and upon the time of contact. In some cases mineraliza-
tion of ground water may result from the mixing of relatively fresh water
with highly mineralized, residual sea water within the water-bearing
formations.
Chemical analyses of the water from 137 selected wells in Manatee
County (fig. 34) were made by the Quality of Water Branch of the U. S.
Geological Survey (table 5). The wells range in depth from about 50 to
more than 700 feet. In addition to these analyses, the chloride content
of water from about 750 wells and the hardness of water from 287 wells
were determined during the investigation and the results are published in
Florida Geological Survey Information Circular No. 19.
Constituents and Properties: The principal mineral constituents and
physical properties of water from wells in Manatee County are discussed
below. The concentrations of mineral constituents are given in parts per
million 1 ppm is approximately equivalent to 8.34 pounds per million
gallons of water. Specific conductance is expressed in micromhos at 25C,
and the hydrogen-ion content in standard pH units. The tolerable limits
given for the ions, unless stated otherwise, are taken from standards
prescribed by the U. S. Public Health Service (1946).
Calcium: Calcium (Ca) is dissolved from limestone, which is predom-
inantly calcium carbonate, by water containing carbon dioxide. Calcium
is a principal cause of hardness in water.
Water from wells that penetrate the Suwannee limestone or older
formations was generally a composite of water from the Tampa formation
and the Suwannee limestone and contained 50 to 320 ppm of calcium.
The calcium content of water from the Tampa formation, ranged from
50 to 325 ppm. The Hawthorn and younger formations yielded water
having a calcium content of 36 to 204 ppm.
















S15






25 j Computed on the basis of: 0
25
T= 100,000 gpd / ft.
S= 0.00014
0 Q=I,000 gpm
30r- I I F i I- I I -_ I- ii i --A l
1.0 5 10 50 100 500 1,000 10,000 100,000
DISTANCE, IN FEET, FROM PUMPING WELL
Figure 88. Graph showing theoretical drawdowns in the vicinity of a well being o
pumped at a rate of 1,000 gpm for selected periods of time. 1












~
-- -.---.---- -.- -. I
____________ 2-----

/ -.--.----
- ---- -?r -
-F


-I.-'
S-U -
~ I


~/KIiL.


I to
~


I ii wrnTe


1 9 1 1 1


--, I A I


EXPLANATION


:' i


JLLLI+ ~Ij
~ i44~~
I.
0
I LL


I __


: ,:14


: I


I.
ii


I 1


I

1


a
=
C


a
U


0


z
C

0
'7.'. ~

C


Figure :34. Mapl of Manatee County showing wells sampled for chemical analysis
and location of line A-B in figure 44.


rL1


16" or


ttt


=sop 0---FT


3b


1-4


' '


i


RR 1 1


1 -


- --


cc 70 o.


-L


- m J


Lm-Lmm"


St 7, w


k/T


1


I


'


aw






REPORT OF INVESTIGATIONS No. 18


Magnesium: Magnesium (Mg) is dissolved principally from dolomite
or dolomitic limestone, and, like calcium, it causes hardness. As magne-
sium is one of the principal mineral constituents of sea water, ground
water that has been contaminated with sea water has a relatively high
magnesium content.
The magnesium content of water from the Suwannee limestone and
older formations ranged from 28 to 167 ppm. Water from the Tampa
formation contained 13 to 118 ppm, and water from the Hawthorn and
younger formations contained 5.8 to 99 ppm, but generally less than 50
ppm.
Sodium and Potassium: Sodium (Na) and potassium (K) are dis-
solved in small amounts from many types of rocks but they constitute
only a small part of the total mineral content of fresh ground water. The
sodium content of water that has been contaminated with sea water is
generally high, as sea water is primarily a solution of sodium chloride.
Water from the Suwannee and older formations contained 0 to 628
ppm of sodium and potassium; water from the Tampa formation con-
tained 0 to 246 ppm; water from the Hawthorn and younger formations
contained 0 to 218 ppm.
Bicarbonate: Bicarbonate (HCOa) in ground water is obtained from
the solution of limestone and other carbonate rocks by water containing
carbon dioxide.
Water from the Suwannee and older formations has a bicarbonate
content of 102 to 264. ppm, and water from the Tampa formation had a
bicarbonate content of 162 to 270 ppm. The bicarbonate content of water
from the Hawthorn ranged from 48 to 557 ppm, but it was generally
higher than that of water from the Floridan aquifer.
Sulfate: Sulfate (SO.) in ground water may be due to the oxidation
of sulfides or to the solution of sulfates of calcium, magnesium, sodium,
or potassium that were deposited by the sea. Large quantities of sulfate
salts in water may impart a bitter taste and have a laxative effect. Sulfates,
of calcium and magnesium cause boiler scale. The tolerable limit of
sulfate in drinking water is considered to be about 250 ppm.
Water from the Floridan aquifer in Manatee County is generally high
in sulfate. Wells penetrating the Suwannee and older formations yielded
water having a sulfate content of 22 to 803 ppm (fig. 35). Water from
the Tampa formation contained 22 to 750 ppm (fig. 36). Water.fi'om the
Hawthorn and younger formations contained 5 to 550 ppm, but generally
less than 200 ppm.
Chloride: Chloride (Cl) in small quantities may be dissolved from
most rocks and soils and is found in large quantities in water that has






-- -. 0 -.35. ...25 2
' J ri -- -- -S"









0--4C









2G..3 *y 1 ,A, "_ O
EXPLANATION 83' 25


S0Ports per million





__. or.-.... 7_., 5 050600. More than 700

Figure 35. Map of western Manatee County showing sulfate content of water from
wells that penetrate the Suwannee limestone and older formations.
1 i RAD "EON
.' % \















wells that penetrate the Suwannee limestone and older formations.





403


il~LL12~

~-~--~3~~CO~"


6ib 1;


823 20 8218'a


I-
!_


'1'

- I-
i I


'I


'I I


- %%


ANNA MARA






EXPRADENTON 20' 821,










i A I U -
--., --I








.A. .. 2 .7_ .02 ._ .3 *._ "


3 "pcer miIon
251-500


82*30'


-501-600


S more then 600


Figure 36. Map of western Manatee County showing sulfate content of water from
the Tampa formation.


K%~jLZ~


~r~t~f~l~


27


82 45'


L'J' 250 or less


G/1


% %


0
0


z
2'







z
0
P

o


I


- I


'-----~~--


1 Z =


--- -' -;--~ "'


L.Wev" I I I


-"JL" _p_, .


;r I


Axql.


.ww -


_- x f


VM


I


J


823d0'


20'


8201'


27'


20' 8, -






1 41,()All C) OtAG CEtCLAIC SunvEY


been contaminated by seal water. Chloride salts do not generally decrease
the potability of water except when present in sufficient quantity to cause
a saltN taste. Water high in chloride content is very corrosive to metal
surfaces and is harmful to most cultivated plants.
The chloride content of water from wells in Manatee County is dis-
cussed in detail in this report under the heading "Salt-Water Contamin-
ation." The chloride content ranged from 12 to more than 1,500 ppm in
water from wells that penetrate the Suwannee limestone and older forma-
tions (fig.37) and from 10 to 920 ppin in water from wells that penetrate
only the Tampa formation (fig. 38). The chloride content of water in
the Hlawthorn and younger formations ranged from 8 to more than 400
ppm (fig. 39) except at the north end of Anna Maria Island, where it
was as much as 44,000 ppim. The extreme saltiness of the water is
apparently due to the solution of mineral salts that were deposited
in the formation.
Iron: Iron ( Fe) occurs in almost all rocks, but the quantity dissolved
by ground water is generally very small in comparison with other con-
stituents. Iron in water causes stains on plumbing fixtures and clothing,
and in concentrations greater than 0.5 to 1.0 ppm it can be tasted. Iron
can generally he removed from water by aeration and filtration.
Fluoride: Fluoride (F) is found in very minor amounts in most ground
water. Water containing fluoride in excess of 1.5 ppm may cause mottling
of the enamel of children's teeth during formation (Cox and Ast 1951, p.
641-648); however, il concentrations of 1.5 ppm or less, fluoride tends
to reduce tooth decay in children and is added to many public supplies
for this reason.
Dissolved Solids: The dissolved-solids concentration represents the
approximate anmout of mineral matter dissolved in the water. Water
containing less than 500 ppm is generally of good chemical quality,
according to U. S. Public Health Service standards, and water contain..
ing up to 1,000 ppm may be used for public supplies if a less mineralized
water is not available.
The dissolved solids of water from wells penetrating both the Suwan-
nee limestone and older formations range from 382 to 3,560 ppm. The
concentration of dissolved solids in water from these wells is shown in
figure 40. Figure 41 shows the concentration of dissolved solids in water
from wells penetrating the Tampa formation, the range being from 376 to
1,700 ppm.
Water from the Hawthorn and younger formations had a dissolved-
solids content ranging from 216 to 1,620 ppm, but most of the water had
350 to 6)00 ppn.





S' 40' 35'2________253' ,2 '
2 /,"7*3h,,_.._







A M A -i VNH







_. .*' ____,_.. : ,, ___ __--- ,----
27 30' 353 ... 8" .,' C ,^,






...5 .-.' "ene ate t-
OVI























Figure 37. Map of western Mlanatee County showing chloride content of water
from wells that penetrate the Suwannee limestone and older formations.







8 245' 0


r1 we


EXPLANATION


I] 25 or less

Figure 38. Map


2326-50


25'T








1%1
2 c i


2 7059


\ N
N
'\ N N N
N N N
N. N. *\ *\*
.~ N N N
N N \ -


82*30C


S101-250


N N. \ '~
~2723'
20 82~18'

~ rr~re than 250


of western Manatee County showing chloride content of water from
the Tampa formation.


C,,




t!1





2?


82r45'


40'


36i21 3 liles I___


ANNAI MARIA



2750': -




sBRA DE' '" -N T ""
BEACH .^ EC6

25 i .... -iy f.
rS ^^^^^^


-_ .'* I i\ !" "r"""r" ~ "" c ~


z27245-
8245'


50 or less


_35' !2"3f 25' 0' 2*2d


1Thfl77i7VTh~1


X/


- J/-.- I !/ -f 9 -


I


.1
.. l i


Ti
F



-j


MAAIME
COU27-30'


N


- I A -%--LA-L- -- l T I


35' EXPLANATION. 830'
FRts per million
0
51-100


--


71


'- -- i -;-- ''23'


more than 100


Figure 39. Map of western Manatee County showing chloride content of water from
the Hawthorn and younger formations.


V


RL|


i I


I I I I "),


II 1 1 1 1 1 1 1 1- I r pr r


I t/ r I r I i .I I74


i a~ 7~l- i0=411I r 1--~S5 2


35


r--j


ml


1





L.


* i Oi.A'j.^A^y'^A.'ilt.yv


' -~~-I'-- ---~-- ~


rr-


I-


I I ---I I


I


fNIL


_JAIR


al






5 40 35' _6230 20 82
- 2 3
























-ooo
45 40' EXPLANATION 30' 25 20 2.'







Ports per million
8oo or less I5ol-75o ]75-lpoo lpo4-2 'o", o 5more tt i,0oo

Figure 40. Map of western Manatee County showing concentration of dissolved
solids in water from wells that penetrate the Suwannee limestone and
older formations.
older format-ions.




20' 82*8


-1L 7
i -1 7- Ills


I I I


Ikc I


NNA MAA


T PAPMASO
FPAMASOL VA
27030 -r -!--
I


1M'i /


II


I'


"/i\


I I 1 -I-k


(LLrh


5uvif


S40' 27*3
LJ41


'717F~{~-r~ PARRISHlY
V1Ae" P -I l


~** N


7'V1


el -I


_____ ~ TN~ ':
11K. N
~ N ,r
N N~


N


- N,


yE ~!' :27*30'
Ne


IA'A
____ / < *
BRADENTON~ ~N N N
N EYAC'*
N, ;-'..




-, ~ 25`258
^^,&A 0' 'A 1- Aore vot e230'500


0 s500 or less


C501-o000


Pcrts per mtlr:~or
El .oor- r250


0j a5t-r5oC


Figure 41. Map of western Manatee County showing concentration of dissolved
solids in water from the Tampa formation.


270


I
r J





824"5


7 mo ftn 1,500


I


m i j -.


-- -- ---------


-4 1 A 6' 6 1 P


'i- -


W I JoF I Z A Z L %%I I I


- --- -- --


ib' .


A I % %


.m6- 0 Ims- i


t~i-i I, i


.tlovi, IN %7


7'c r~ 1 1


4-4 1


~dfY~i


i F-RF


z I V-01-Y I f


--


C-


I-


a90'0


E.


11


v


Czi *aF


. J% /


/i


rvrl- 11.


M:T


' 1 J~'
*\2-\


7
16






68


Hardness: The hardness of a water is due almost entirely to the salts
of calcium and mIagnesium. Hardness caused by calcium and magnesium
equivalent to the carbonate and bicarbonate is referred to as carbonate
hardness. lardness caused by the chlorides, sulfates, and nitrates of
calcium a(lnd mnagnesiumn is known as noncarbonate hardness. The most
noticeable effects of hardness are the formation of soap curds and the
lack of suds when soup is added to the water. Hard water also causes a
scale il oilers or vessels ill which the water is heated.
Water having a hardness of less than 50 ppm is generally satisfactory
for most purposes. Hardness between 50 and 150 ppm does not seriously
interfere with the 11se( of water for most purposes but does increase the
U1s of soap andl is generally ObjectiOnablle to ,people who are accustomed
to soft water. Water having a hardness of more than 150 ppm is rated
its hard andl is commonlyV softened for domestic and other uses.
Figure 42 shows the hardness of water from wells that penetrate the
Suwannitce and older limestones; it ranged from 240 to 1,680 ppm. Figure
43 shows the hardness of water from the Ta111pa formation; it rallge(d
from 228 to 1,09()0 ppm. Wells that did not penetrate the Floridan aquifer
yielded water ranging in hardness from 140 to 916 ppm, bult the hardness
was generally less than 500 ppm.
Sprcifict/fr ( idclamn:c: The specific conductance of water is a measure
of its capacity to conduct all electric current and depends on the concelln-
tration andl ionization of the minerals in solution, It is useful in determin-
ing the mitieralization of a water. The specific conductance of water from
the Floridlan aquifer in the county ranged from 478 to 5,260 micromhos.

Hydrogen Sulfide: Hydrogen sulfide (H. S) is a gas that gives water
ali objectionable odor andl causes corrosion of plumbing. It can be
remove ,d ib aeration. Water containing hydrogen sulfide is often referred
to as "sulifur water." No determinations were made of the hydrogen
sulfide content of water from wells in Manatee County; however, the
gas is present iln water from mosatwells that penetrate the Hawthorn
and older formations.
Ilydrogen-ion Concentration (pll): The pH value of a water indicates
the instantaneous concentration of hydrogen ions. Water that has a pH
of 7.0 is said to be neutral. Water having a pTH of less than 7.0 is acidic
and may be corrosive; water having a pH greater than 7.0 is alkaline and
not generally corrosive. The pH of water from the Floridan aquifer in
Manatee (Coumnntv ranged from 7.2 to 8.5, and the pH of water from the
younger formations ranged from 7.3 to 8.2.


Ft'lom)llA GEOLO(GICALI SUR\VEN











J-
eA ,er?' a7 ~* --- ero





' 4-- 3 5 e 2V_.o:wr l ^ a












,250 or ess -. '
^25I- 500 '7
,7 5 I : '^ ^4 A 75 i'." r'"





// r^e stta, / /
/ ./ /-- --

ES ] o,1- ,'o^ ^^, / /, ,, .., --







.0. ,. ... .. .- -.- .. --.- -

.. ,I.



* ,.* ,*/. ;- .- .- ," "-- -,-, ,



-.-













!250 rl s s

.-50i- 750,-

W 27* 5
r-es ae 2r 7$$ V/1








Figure 43. Map of Manatee County showing hardness of water from the Tampa
formation.
. ,- ," i ; 01 ,/ ,. .
__ _51_-5.0,0 1W.













formatiom-






REPORT OF INVESTIGATIONS No. 18


SALT-WATER CONTAMINATION
In coastal areas where the water-bearing formations are hydraulically
connected to the sea, the depth to salt water is directly related to the
height that fresh water stands above sea level. The lowering of the water
table or artesian pressure head in such areas may permit sea water to
enter the water-bearing formation and contaminate the fresh water.
Salty water is present in the Floridan aquifer at relatively shallow
depths throughout much of the coastal area of Florida. At some places,
the lowering of the artesian pressure head by the withdrawal of large
quantities of water from wells has caused the encroachment of sea water
into the aquifer. In most of the coastal area, however, the head is suffi-
ciently high to prevent encroachment of water directly from the sea; thus,
the extensive occurrences of salty water are probably due to residuals of
sea water that entered the aquifer prior to Recent time.
The Floridan aquifer was partly filled with sea water several times
during the interglacial stages of the Pleistocene epoch, when the sea stood
above the present level. Since the last recession of the sea, the circulation
of fresh water through the aquifer has been gradually diluting and flush-
ing out the salty water. In much of the coastal area, the flushing
is incomplete and a part or all of the water-bearing formations still contain
water which, although considerably less salty than sea water, is too salty
for most uses. The dilution and flushing of the salty watef will continue
as long as the artesian pressure head remains relatively high. Excessive
lowering of the head will retard the flushing action and may cause an
upward movement of the salty water from the lower zones of the aquifer,
except where such movement is prevented by impermeable beds. If the
head is lowered far enough, the seaward movement of water in the aquifer
will be reversed, and thus will permit sea water to enter the aquifer.
The dissolved mineral matter in sea water consists predominantly of
chloride salts. The chloride content of ground water, therefore, is
generally a reliable index of contamination by sea water. Water samples
from about 750 wells were analyzed to determine the chloride content of
the water in the Floridan aquifer and in the Hawthorn and younger
formations.
The analyses show that in most of the county the water in the Floridan
aquifer has a chloride content of 25 ppm or less. In western Polk County
the water in this aquifer has a chloride content of about 10 ppm, and in
eastern Manatee County, about 15 ppm. It gradually increases westward,
in the direction of ground-water movement. The principal constituents
of water from selected wells that penetrate the Floridan aquifer (see
line A-B in fig. 84) are shown graphically in figure 44, to illustrate the
increase in mineral content of the water as it moves toward the coast.






FLORIDA GEOLOGICAL SURVEY


As shown in figures 37 and 38, the water in the Floridan aquifer in much
of the coastal area has a chloride content ranging from 26 to more than
500 ppm. The areas of highest chloride content are generally the areas
of lowest artesian pressure head (fig. 25, 26); however, the mean artesian
head along the coast is sufficiently high to prevent sea water from entering
the aquifer at depths less than about 650 feet.


28-34-2 28-31-2
WELL NUMBERS


Figure 44. Graph showing the principal constituents of water from selected wells
along line A-B in figure 34.

Two wells on Mullet Key, about five miles north of Anna Maria Island,
yield water from the Floridan aquifer having a chloride content of about
900 ppm. A well on the Sunshine Skyway, about three miles south of
the Pinellas County peninsula, yields water from the Floridan aquifer
having a chloride content of 1,350 ppm. The relatively low chloride
content of water from these wells indicates that most of the salt water
has been flushed from the upper part of the Floridan aquifer in an area
extending a considerable distance offshore.
As shown in figure 38, the water from the Tampa formation contains
less than 250 ppm of chloride throughout most of the coastal area. This in-
dicates that most of the salty water has been flushed out by the circulation






REPORT OF INVESTIGATIONS No. 18


of fresh water, although a few wells at the northern end of Anna
Maria Island yield water from the Tampa formation containing as much
as 460 ppm of chloride. The flushing of the salty water from the Suwan-
nee limestone and older formations is less complete than it is from the
Tampa formation (fig. 37, 38). The water from wells that penetrate the
Suwannee limestone and older formations is principally a composite of
water from the Tampa formation and Suwannee limestone, and it contains
less than 500 ppm of chloride in most of the coastal area. However,
several deep wells in the vicinity of Palma Sola Bay yield water having a
chloride content ranging from about 1,000 ppm to more than 1,500 ppm.
The chloride content of the water in the Suwannee limestone and older
formations is probably much higher than indicated by the analyses of the
composite samples.
Water samples were collected at various depths in selected wells to
determine the chloride content of water from the different producing
zones. As indicated by graphs in figures 12, 15, 45, and 46, the saltier
water enters the wells from the deep producing zones and is diluted by
fresher water from other producing zones as it moves up the well bore.
For example, the analyses of samples collected in well 28-41-4 (fig. 12)
show that the chloride content of water from the Suwannee limestone at
the bottom of the well was about 2,400 ppm, whereas at a depth of 500
feet, where additional water entered the well, the average, chloride con-
tent was about 900 ppm. At a depth of about 380 feet, where a consider-
able quantity of water entered the well from the Tampa formation, the
average chloride content was about 550 ppm.
Periodic analyses of water samples show that the chloride content of
the water changes with changes in artesian pressure head. Generally, a
decrease in head is accompanied by an increase in chloride content, and
vice versa (fig. 20, 22). This relationship indicates that the lowering
of the head causes an upward movement of the salty water from the deep
formations. The relationship may also reflect variations in the proportion
of the total yield of the well that is obtained from each producing zone.
During periods of heavy withdrawal, the head in the Tampa formation
in localized areas is slightly less than the head in the deeper formations.
During such times, the proportionate yield from the deeper formations is
increased, and the chloride content of the water is higher.
Although the periodic determinations of chloride content indicate that
the lowering of the artesian pressure head causes an upward movement
of salty water from the deeper formations, they do not show any lateral
expansion of the contaminated area. However, a continued decline of
the piezometric surface in the coastal area will eventually result in lateral
encroachment from the ocean. Lateral encroachment can be prevented


78








14 FLORIDA GEOLOGICAL SURVEY


3 SELF- POTENTIAL RELATIVE RESISTIVITY CHLORIDE CONTENT
AGE 10 mv 25ohms (ports per million)
..- 200 300 400 500

0- aand-C,





100 -- 1..-- I00






-00 --------- ------- i ---- ---- 0
4 z
to








3* 500 -- 300-- 400
i 0 i








400 4 00





S500 -00
5u 0


.600


Figure 45. Graph showing data from well 27-36-1, four miles southwest of Bradenton.






BRPOtT OF INVESTIGATIONS No, 18


CHLORIDE CONTENT
(parts per million)
)0 1,500 2,000


TEMPERATURE
(degrees
Fahrenheit)
80 81
i-- -10


1001 ---- 00
J


-J

U)

< 200 --- 200



O
0


I-
U 300- 300
LL
z













500 500




Figure 46. Graph showing chloride content and temperature of water from well
29-40-8, two miles north of Cortez.


75






FLORIDA GEOLOGICAL SURVEY


and upward encroachment retarded by avoiding excessive drawdown,
through the use of proper well spacing and controlled discharge rates
in the coastal area.
SUMMARY AND CONCLUSIONS
The investigation of the ground-water resources of Manatee County
consisted primarily of collecting and evaluating data from more than
900) private and public wells. The principal results are summarized
below:
The county is underlain below depths ranging from about 175 to 875
feet, by a thick section of limestone consisting of formations of Eocene,
Oligocene, and Miocene ages. The limestone formations penetrated by
water wells are the Avon Park limestone and the Ocala group of Eocene
age, the Suwannee limestone of Oligocene age, and the Tampa formation
of early Miocene age. These formations are overlain by the Hawthorn
formation of middle Miocene age, which consists of interbedded marl,
limestone, and sand. The Hawthorn is overlain by deposits of sand, clay,
shells, and limestone of Pliocene and Pleistocene age, which range in
thickness from a few feet to about 90 feet.
Water in usable quantities generally occurs in all formations pen-
etrated by wells. The sand, limestone, and shell beds of Pliocene and
Pleistocene age yield water to many domestic wells. The water in these
deposits is replenished by local rainfall. The Suwannee limestone and
Tampa formation, which form a part of the Floridan aquifer, are the
principal sources of ground water in the county. The water in these
formations occurs in permeable zones separated by relatively impermeable
layers which retard the vertical movement of the water. The water is
replenished by rainfall in northern Polk County and, possibly, in north-
eastern Manatee County. The Hawthorn formation serves as a confining
layer for the water in the Floridan aquifer. Beds of sand, shells, and
limestone within the Hawthorn are the source of many small irrigation
and domestic water supplies.
The artesian pressure head of the water in the Hawthorn formation is
generally several feet lower than that of water in the Floridan aquifer.
Because of this difference in head, water from the Suwannee limestone
and Tampa formation leaks upward into the permeable beds in the Haw-
thorn formation through wells that are open to all these formations. The
depression in the piezometric surface in the vicinity of Palma Sola (fig.
25) is probably due in part to such leakage through unused irrigation
wells.
Water-level records show that significant changes in artesian pressure
head result from daily and seasonal variations in withdrawal of water
from wells. During periods of heaviest withdrawal, the piezometric






REPORT OF INVESTIGATIONS No. 18


surface is lowered four or five feet throughout the county and as much
as 10 feet at some places. The increase in both seasonal and perennial
use of water since 1948 has resulted in a progressive decline of artesian
head in parts of the county and a progressive increase in the magnitude
of seasonal fluctuations.
Because of the decline in head, pumping is necessary in many areas
where sufficient quantities of water were formerly obtained by natural
flow. In other areas, the depth of the water below the land surface has
exceeded the lift capacity of centrifugal pumps, and turbine pumps must
now be used.
The chloride content of the artesian water in most of the county is
about 15 to 25 ppm, but in a zone about 3 to 10 miles wide along the
coast it ranges from 26 to more than 1,500 ppm. This indicates that the
ground water is contaminated by salt water. The salty water is probably
a diluted residue of sea water which entered the aquifer during Pleisto-
cene times and which has not been completely flushed from the aquifer.
The mean artesian head along the coast is sufficiently high to prevent the
encroachment of salt water directly from the sea.
A few wells yield water containing more than 400 ppm of chloride
from the Tampa formation, but the water in the Tampa generally contains
less than 250 ppm of chloride, indicating that most of the salt water has
been flushed out. The flushing is less complete from the Suwannee lime-
stone, in which the water at some places contains more than 2,000 ppm
of chloride. Throughout most of the coastal area, however, the chloride
content of water in the Suwannee is less than 500 ppm. The water in the
Eocene formations along the coast is probably too salty for most uses.
Periodic determinations of chloride content show that the chlorinity
of the water changes with significant changes in artesian pressure head.
Some wells that show a progressive decline in head show also a progres-
sive increase in chloride content, indicating that the lowering of head
causes an upward migration of salty water from the deeper formations.
Little or no expansion of the contaminated area has occurred during
the period of investigation; however, if the piezometric surface continues
to decline in the coastal area, lateral encroachment from the ocean will
eventually result. Lateral encroachment can be prevented and vertical
encroachment retarded by avoiding excessive drawdowns, through the
use of proper well spacing and controlled discharge rates in and adjacent
to the contaminated area.
Water-level measurements and periodic determinations of the chloride
content of water from selected wells should be continued, so that any
changes in the head and chlorinity of the artesian water can be detected
and controlled.


- ---~-L ~L ----IL_






FLORIDA GEOLOGICAL SURVEY


REFERENCES
Anders, R. B. (see Peek, H. M.)
Applin, Esther R. (see Applin, Paul L.)
Applin, Paul L.
1944 (and Applin, Esther R.) Regional subsurface stratigraphy and structure
of Florida and southern Georgia: Am. Assoc. Petroleum Geologists Bull.,
vol. 28, no. 12.
Ast, D. B. (see Cox, C. R.)
Black, A. P.
1951 (and Brown, Eugene) Chemical character of Florida's waters-1951:
Florida State Board of Cons., Division Water Survey and Research,
Paper 6.
Brown, Eugene (see Black, A. P.)
Collins, W. D.
1928 (and Howard, C. S.) Chemical character of waters of Florida: U. S.
Geol. Survey Water-Supply Paper 596-G.
Cooke, C. W.
1945 Geology of Florida: Florida Gecol. Survey Bull. 29.
Cooper, II. H., Jr.
1940 (and Jacob, C. E.) A generalized graphical method of evaluating forma-
tion constants and summarizing well-field history: Am. Geophys. Union
Trans., vol. 27.
Cox, C. R.
1951 (and Ast, D. B.) Water fluoridation a sound public health practice:
Am. Water Works Assoc. Jour., vol. 43, no. 8.
Ferguson, G. E. (see Parker, G. G.)
Gunter, Herman (see Sellards, E. H.)
Howard, C. S. (see Collins, W. D.)
Jacob, C. E. (see Cooper, H. HI., Jr.)
Love, S. K. (see Parker, G. G.)
MacNeil, F. S.
1950 Pleistocene shorelines in Florida and Georgia: U. S. Geol. Survey Prof.
Paper 221-F.


Matson, G.
1918

Parker, G.


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


1950 (and Stringfleld, V. T.) Effects of earthquakes, trains, tides, winds, and
atmospheric pressure changes on water in the geologic formations of
Southern Florida: Econ. Geology, vol. 45, no. 51.
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.
1955 (and Anders, R. B.) Interim report on the ground-water resources of
Manatee County, Florida: Florida Geol. Survey Inf. Ciro. 6.
Puri, Harbans
1953 Zonation of the Ocala group in peninsular Florida (abstract): Jour.
Sedimentary Petrology, vol. 23.
Sanford, Samuel (see Matson, G.C.)


78






REPORT OF INVESTIGATIONS No. 18 79

Sellards, E. H.
1913 (and Gunter, Herman) The artesian water supply of eastern and southern
Florida: Florida Geol. Survey 5th Ann. Rept.
Stringfleld, V. T. (also see Parker, G. G., 1950)
1933 Ground-water investigations in Florida: Florida Geol. Survey Bull. 11.
1936 Artesian water in the Florida peninsula: U. S. Geol. Survey Water-
Supply Paper 778-C.
U. S. Public Health Service
1.946 Public Health Reports: vol. 61, no. 11, p. 371-384.
Vernon, R. 0.
1951 Geology of Citrus and Levy counties, Florida: Florida Geol. Survey
Bull. 33.
Wenzel, L. K.
1942 Methods for determining permeability of water-bearing materials, with
special reference to discharging-well methods: U. S. Geol. Survey Water-
Supply Paper 887.








Table 5. Chemical Analyses of Water from Wells in Manatee County
(Analyses, in parts per million, by U.S. Geological Survey)


Mag-
nesium
Mf e


Sodium
and po-
tassium
(NV +K)


Bicar-
bonate
(HCO) -'


Well No.
i


Date
of col-
lection


Chloride
(Cl)


Dis-


solved
solids


3- 9-55
3- 7-55
3- 7-55
4- 1-55
3-23-55
3- 9-55
3- 9-55
4- 1-55
2-24-55
1-26-54
1-29-54
2-16-55
2-16-55
2-16-55
3- 7-55
3-23-55
3- 9-55
4- 1-55
4- 1-55
1-20-54
3- 7-55
3-23-55
3-23-55
3-23-55
4- 1-55
2-16-55
2-21-55
2-21-55
2-18-55


Hardness as Specific
CaCO; conduct-
ance-
(mi-
SNoncar- cromhos
Total bonate at 25*C)


Calcium
(Ca)


72
212
162
36
140
166
146
94
151
126
149
109
120
186
140
139
154
70
145
170
122
130
141
144
73
192
188
154
252


38 1.6' 208
113 146 !?64
93 96 162
17 55 248
69 29 165
84 12 170
73 .01 167
51 50 236
71 55 166
52 ........ 172
58 ........ 162
20 26 309
18 30 412
91 195 160
78 82 172
67 37 175
78 12 170
34 49 250
45 160 527
103 186
80 78 178
60 49 178
65 35 171
68 32 166
35 51 362
88 114 162
77 65 194
23 26 338
115 171 156


Sulfate
(S04)


135
750
615
15
472
508
412
268
495
385
468
108
25
495
480
475
498
106
124
472
500
475
502
515
55
625
535
126
660


!


20 430-
280 1,700
158 1,270
44 342
49 966
83 1,120
66 940
57 716
97 988
65 860
80 974
32 476
54 534
283 1,530
147 1,130
46 944
51 960
74 606
236 1,110
145 1,100
97 1,010
27 862
24 928
26 936
58 504
217 1,410
149 1,170
90 664
467 1,970


20-10-1
23-38-1
23-38-3
*24-26-1
25-29-2
25-31-2
25-31-7
*25-32-1
25-33-5
25-34-1
25-34-2
*25-34-3
*25-34-9
25-35-2
25-40-3
26-29-3
26-30-3
*26-31-2
*26-33-5
26-35-3
26-41-2
27-28-1
27-29-1
27-30-3
*27-31-2
27-34-1
*27-35-1
*27-35-2
27-35-3


pH


166
860
654
160
498
621
527
251
532


37
707
529
479
565
109
115

425
480
494
30
709
627
201
972


635
2,180
1,610
529
1,220
1,430
1,240
967
1,320
1,140
1.250
728
778
1,980
1,440
1,180
1,250
817
1,650
1,540
1,330
1,110
1,115
1,150
802
1,800
1,580
1,000
2,660


336
994
786
160
633
760
664
444
668
528
614
354
374
838
670
622
704
314
547
690
634
571
620
630
326
841
786
478
1,100


-i
Temper-
ature
(*F)

79
80.5
79.2
79.5
79.5
78.5
80.
78
78.5


79.2
82
80

80.
78
81
79
79.8
74
79
75.5


7.7
7.4
7.4
7.5
7.4
7.5
7.5
7.5
7.7
7.5
7.4
7.3
7.4
7.4
7.3
7.4
7.4
8.1
7.3
7.3
7.4
7.4
7.4
7.3
7.4
7.4
745
7.5
7.5


I


I


0
L0


0q
CA





Table 5 (continued)

Hardness as Specific
Sodium CaCOa conduct-
Date Calcium Mag- and po- Bicar- Sulfate Chloride Dis- ance Temper-
Well No. of col- (Ca) nesium tassium bonate (SO4) (Cl) solved (mi- ature pH
election (Mg) (Na+K) (HCO) solids Noncar- cromhos (0F)
Total bonate at 25*C)
*27-37-5 2-17-55 97 19 20 345 15 46 426 320 138 681 75 7.5
27-38-3 3- 3-55 208 100 101 162 575 296 1,550 930 798 2,100 79.9 8.2
27-38-7 1-20-54 219 88 ........ 166 595 300 1,580 912 ........ 2,120 79 7.4
27-39-4 3- 3-55 120 82 64 195 355 174 1,030 636 476 1,390 78 7.4 .
27-39-12 1-20-54 229 94 ........ 168 682 240 1,650 958 ........ 2,030 80 7.4
27-41-3 1-20-54 134 71 ........ 200 392 112 1,020 628 ........ 1,330 79 7.4 0
28-16-1 3- 9-55 50 28 15 264 22 24 382 240 24 473 79 7.5 P
28-29-3 3-23-55 118 54 29 178 388 21 760 516 370 991 78 7.5 -.
*28-30-7 4- 1-55 113 9.2 26 316 72 30 448 320 61 678 75 7.5
28-31-2 1-28-54 164 69 ........ 168 545 28 1,020 696 ........ 1,250 85 7.3
.*28-32-2 4-1-55 71 27 43 326 19 67 482 288 22 748 ........ 7.5
*28-33-2 4- 1-55 36 20 13 196 14 18 216 172 12 376 ........ 7.4
*28-34-1 3-17-55 229 42 78 250 490 141 1,220 744 539 1,600 ....... 7.4
28-34-2 3-25-55 177 78 47 102 622 94 1,280 762 679 1,570 78 7.9 Q
*28-34-5 3-25-55 107 10 40 317 62 50 486 308 48 724 74 7.3 0
*28-34-7 3-25-55 77 28 29 301 72 34 420 307 61 639 ........ 7.3
*28-35-12 4- 1-55 101 5.8 14 314 21 20 344 276 19 553 ........ 7.5 z
28-37-1 1-20-54 235 97 ........ 216 500 578 1,910 990 ........ 2,880 78 7.3 o
*28-37-9 3-3-55 123 13 25 412 15 44 444 360 23 721 ........ 7.8
128-38-6 5-21-53 326 135 412 160 803 925 2,900 1,370 1,240 4110 ....7.5
28-40-8 1-20-54 158 96 ........ 204 415 232 1,230 740 ........ 1.700 79 7.3
28-41-5 3- 7-55 320 167 414 178 675 1,090 3,220 1,480 1,340 4,580 80.3 7.2
28-41-6 3- 7-55 134 83 70 204 435 148 1,100 676 509 1,400 76 7.5
28-41-7 3- 7-55 110 66 85 224 365 118 1,090 546 363 1,180 77.8 7.9
29-26-3 3- 4-55 52 34 23 209 99 32 376 270 109 604 77.5 7.6
29-26-5 3- 4-55 99 49 16 190 280 25 604 448 293 833 80 7.8
*29-29-3 4- 1-55 38 28 40 232 38 47 354 210 20 561 ........ 7.6
29-29-6 3- 4-55 136 .63 15 174 440 22 804 598 456 1,050 79.7 7.6
29-32-2 1-27-54 168 59 ........ 176 512 27 1.000 664 ........ 1,210 79 7.5
S1Io








Table 5 (continued)


Well No.


Date
of col-
lection


*29-32-5 3-25-55
*29-35-1 2-21-55
29-35-2 1-28-54
29-35-7 2-24-55
*29-36-7 3- 3-55
*29-36-9 2-23-55
*29-36-14 2-14-55
*29-36-18 2-14-55
29-37-9 2-14-55
29-40-8 1-29-54
29-42-3 3- 7-55
30-25-1 3- 4-55
30-27-6 3- 4-55
30-28-2 2-14-55
30-30-1 1-28-54
*20-37-2 2-14-575
20-37-6 3- 3-55
*20-37-7 3- 3-55
30-27-8 1-28-54
*W0-28-1 3- 3-55
*30-28-5 3- 3-55
30-28-7 3- 3-55
30-38-9 1-21-54
*30-39-4 3- 3-55
30-39-5 7-18-51
30-41-1 2-16-55
31-24-1 3- 4-55
31-o0--1 1-27-54
*31-30-3 3-25-55


Calcium
(Ca)


40
110
191
222
108
132
86 1
82
204
147
260
94
124
126
128
113
214
118
197
77
106
160
172
108
204
214
74
134
74


Mag-
nesium
(Mg)

9.8
21
88
101
17
22
9.8
26
99
89
149
46
65
61
50
9.2
102
26
106
31
51
63
104
34
99
107
36
52
61


Hardness as


Sodium CaCOs conduct-
and po- Bicar- Sulfate Chloride' Di.- i: ance Temper--
i tassium bonate (SO) (Cl) solved (mi- ature pH
(Na +K) (HC03) solids Noncar- cromhoes (cF)
Total bonate at 25C)
31 48 102 44 280 140 101 431 8.1
29 362 54 50 508 361 65 787' 75 7.3
........ 164 668 52 1.250 840 ........ 1.500 78 7.3
21 161 755 69 1.380 970 838 1,610 79.3 7.6
.0 372 8 18 400 340 34 606 76 7.3
39 426 6 106 620 420 71 1.010 ........ 7.4
31 292 12 50 392 255 16 615 76 7.9
S32 323 35 56 446 312 48 700 76 7.9
I 61 169 665 155 1.350 916 778 1,740 79.5 7.3
....... 210 255 598 1,580 678 ......... 2.550 79 7.4
S394 184 700 878 2.630 1,260 1.110 3.820 79.8 7.4
6.4 187 245 21 578 424 271 780 81.5 7.6
10 180 400 25 776 577 430 994 82 7.5
.0 172 368 26 802 566 425 1.040 81.5 7.5
........ 174 390 23 ........ 524..... 995 77 7.5
17 351 12 41 410 320 33 637 76.5 7.3
43 154 690 144 1.450 954 828 1,750 78 7.3
8.3 270 116 55 516 402 181 781 76.5 7.7
........ 180 645 295 1.660 930 ........ 2,180 79 7.4
45 241 100 82 550 320 123 768 ........ 7.9
20 202 259 58 706 474 309 957 77.3 7.4
33 210 355 134 1,080 658 485 1,380 75 7.6
........ 182 542 208 1,410 780 ........ 1.810 ........ 7.3
46 248 175 89 662 410 207 911 76.2 7.4
218 186 542 472 1,660 916 769 2.530........ 8.2
229 182 540 540 1,910 974 825 2.830 79.5 7.3
15 196 170 20 438 332 172 650 79 7.5
........ 176 432 24 862 546 ........ 1.040 77 7.5
75 390 165 76 696 436 117 090 ........ 7.3


0


Specific




Table 5 (continued)

Hardness as Specific
Sodium CaCO conduct-
Date Calcium Mag- and po- Bicar- Sulfate Chloride Dis- ance Temper-
Well No. of col- (Ca) nesium tassium bonate (SO4) (Cl) solved (mi- ature pH
election (Mg) (Na-+K) (HCO3) solids Noncar- cromhos (CF)
Total bonate at 250C)


31-31-2
*31-32-2
*31-32-3
31-32-4
31-32-8
*31-34-1
31-34-10
31-34-13
31-37-3
31-37-6
31-37-10
*31-38-4
31-39-2
*31-39-3
*31-43-2
31-43-2
32-25-1
32-27-2
32-27-3
32-29-2
32-32-1
32-32-7
32-33-2
32-33-4
*32-33-6
32-34-6
33-23-1
*33-25-1
33-31-1


1-27-54
3-25-55
3-25-55
3-25-55
2- 8-55
3-25-55
1-21-54
2-4-55
1-29-54
1-21-54
2- 7-55
2-18-55
2-18-55
2-18-55
11-20-50
1-20-54
2-15-55
2-15-55
2-15-55
1-27-54
2- 7-55
2- 8-55
2- 7-55
2- 4-55
3-25-55
2- 4-55
2- 8-55
3-25-55
2- 4-55


137
178
58
163
150
57
193
236
227
187
~2
104
286
118
1,260
216
78
82
94
103
153
172
281
169
179
173
75
44
136


53
80
78
67
66
34
117
98
97
113
99
56
152
46
1, 590
93
39
48
48.
47
76
69
109
73
74
81
32
23
60


58
49
28
42
20
i133

1 i67
S35
628
25
13.100

3.2
1.4
54.
51
105
33
47
66
6.4
11
23


170
365
259
165
176
331
162
172
172
188
162
220
188
2 2
201
194
188
188
200
178
124
160
156
156
193
120
180
262
192


448
490
278
542
535
19
608
790
722
580
725
240
675
199
1.710
4V0
178
215
232
342
6F0
570
750
575
580
660
153
5 4
420


23
64
50
31
26
24
92
225
282
232
328
96
1,310
100
25.500
440
28
22
21
23
38
70
332
48
65
87
18
6
30


860
1. 120
712
1.010
914
352
1,260
1.670
1.770
1.510
1,820
750
3.560
680
43.500
1.570
454
492
550
752
1.100
1.090
1.870
1.140
1.140
1.270
444
254
856


556
773
465
682
646
282
802
992
966
858
986
490
1.340
484
9,800
924
355
402
432
450
694
712
1.150
722
751
764
318
2041
586


474
253
497
502





310
1186



294
9,690

248
2851



8594
593
666
171
204
428


1.050
1,510
1.030
1.250
1,160
580
1,510
2,120
2.240
1.950
2,390
1,040
5,260
963
53,600
2.320
671
725
784
904
1,300
1.350
2.400
1.340
1.430
1.500
636
418
1. 100


77

79.8
78


78
77
80
75
81.5
75.5
78
81.4
79
80
77
79
79
84
80

82
81


7.4
7.2
7.4
7.2
7.7
7.3
7.5
7.5
7.3
7.4
7.5
7.4
7.5
7.3
7.6
7.4
7.4
7.7
8.5
7.5
7.9
7.4
7.5
7.9
7.3
8.0
7.8
7.3
7.9


- -









Table 5 (continued)


Sodium
Date Calcium Mag- and po- Bicar- Sulfate Chloride!
of col- (Ca) nesium tassium ; bonate (SO4) (Cl)
election i (Mg) (Na+K)! (HCO,)

2- 4-55 195 78 105 168 580 208
1-21-54 176 107 ........ 172 530 202
2- 8-55 79 35 17 208 176 18
3- 2-55 80 41 0.9 192 178 19
2-15-55 88 45 5 188 220 23
2- 4-55 133 55 44 172 460 24
2- 4-55 114 65 69 120 505 56
2- 4-55 195 82 167 180 595 297
1-21-54 179 75 .. 168 535 175
2- 8-55 199 88 143 160 590 301
2- 8-55 136 57 37 172 425 50
2- 7-55 148 62 66 172 445 117
1-28-54 153 64 ........ 174 428 118
2- 8-55 171 72 111 178 510 204
2- 7-55 116 52 39 178 355 52
3- 9-55 106 58 34 188 310 72
1-27-54 69 13 ........ 270 40 28
2- 4-55 123 50 31 176 360 44
1-22-54 122 47 ........ 190 320 35
2- 4-55 159 69 62 180 505 100
2- 4-55 129 57 48 188 420 50
1-22-54 111 50 ........ 193 335 31


Hardness as
CaCO,


Well No.


33-33-8
33-35-4
34-23-2
34-25-3
34-29-1
34-31-2
34-32-3
34-33-7
34-34-2
34-35-2
35-31-2
35-32-11
35-33-6
35-34-5
36-31-1
36-32-2
37-29-3
37-31-3
37-32-10
38-32-5
38-32-9
38-33-5


Dis-
solved
solids
Total
1,390 807
1,280 770
510 341
454 368
570 404
792 558
952 552
1,530 824
1,280 760
1,560 858
852 574
1,040 624
1,040 648
1,330 722
748 504
788 503
388 228
738 512
736 500
1,030 680
820 556
754 482


Specific
conduct-,
ance Temper-
(mi- ature
cromhos (F)
at 25C)
1,810 80
1,770 77
692 80
687 79
813 80.1
1,040 77
1,150 79
2,070 81
1,670 78
2,110 79
1,120 78
1,360 79
1,400 77
1,740 79
1,020 79
1,070 78
556 76
1,010 80
976 77
1,340 81
1,070 78
950 76


Analysis of water from the Hawthorn or a younger formation.
1 Contains silica (SiO2), 21 ppm; iron (Fe) in solution, 0.00 ppm; total iron, 0.59 ppm; fluoride (F), 1.9 ppm; nitrate (NO3),
0.4 ppm; color, 5.
2 Contains silica (SiO2), 29 ppm; iron (Fe) in solution, 0.00 ppm; total iron, 0.07 ppm; fluoride (F), 0.9 ppm; nitrate (NOQ),
2.9 ppm; color, 12.
'Contains silica (Si02), 8.6 ppm; iron (Fe), in solution, 0.16 ppm; total iron, 5.0 ppm; fluoride (F), 0.2 ppm; nitrate (NO3),
22 ppm; color, 40.


Noncar-
bonate
670
170
210
250
417
454
676
728
433
484
576
358
349
368
542
402
. .. .. ...


pH


0


CA


7.4
7.3
8.0
7.7
7.3
7.6
8.1
7.3
7.3
7.6
7.6
7.6
7.5
7.6
7.6
7.5
7.7
7.5
7.6
7.7
7.7
7.7




Table 6. Water-Level Measurements
(All measurements in feet with reference to measuring point)

Water Water Water Water
Well No. Date level Date level Date level Date level
23-38-1............... 5-16-53 11.0 10-13-53 11.2 7- 1-54 12.9 3- 7-55 8.5
6- 3-53 9.5 12-11-53 11.0 8-16-54 13.2 7-21-55 11.6
7-23-53 10.2 3- 4-54 11.2 9-16-54 12.2 10-27-55 12.1
9-16-53 11.5 5-17-54 12.5 1-31-55 8.5 12-15-55 10.5
9-16-53 11.3 ............ .................................... ............ ............
23-38-2............... 3-16-54 14.0 8-21-51 15.2 7-29-52 13.4 2- 4-53 11.5
4-16-51 12.6 4-11-52 12.0 10-29-52 15.0 3-31-53 11.9
6- 6-51 12.6 5-25-52 10.8 12-15-52 11.8 4-30-53 11.0
25-31-7............... 10-27-52 5.2 7-22-53 3.46 12-22-54 4.2 6- 6-55 1.75
12-15-52 2.95 9-16-53 5.2 1-31-55 2.2 7-21-55 3.2
2-11-52 4.10 10-15-53 5.3 3- 9-55 0.35 9-15-55 4.2
3-31-53 0.47 12-18-53 4.8 4- 6-55 1.4 10-27-55 1.1
5-16-53 0.9 9-16-54 4.9 5- 9-55 2.2 12-13-55 1.4
6- 2-53 0.8 ............ ........................ ............ ............ ............
25-40-3B............... 3-16-51 14.0 7-29-52 14.2 6- 3-53 13.9 3- 4-54 14.0
4-16-51 15.5 10-29-52 14.7 7-23-53 14.3 5-17-54 14.0
6- 6-51 15.1 12-15-52 15.3 9-16-53 14.5 7- 1-54 15.2
5-21-51 16.1 2- 4-53 14.8 10-13-53 15.2 8-16-54 16.1
4-11-52 14.0 3-31-53 14.2 12-11-53 15.0 9-16-54 15.0
6-25-52 13.8 5-16-53 13.6 ........................ ............ ............
26-30-5............... 3- 1-54 9.0 11- 8-54 8.0 4- 6-55 8.3 9-15-55 10.1
6-30-54 10.2 12-22-54 10.0 5-10-55 2.35 10-27-55 6.7
9-17-54 11.1 1-31-55 6.5 6- 6-55 3.2 12-13-55 7.2
27-39-9............... 11-13-52 1.85 3-30-53 3.65 7-22-53 3.55 12-18-53 5.3
2-12-53 6.5 5-15-53 1.55 10-13-53 3.2 ......................


0

0








0
o0
00a









Table 6 (continued)


Well No.


27-41-2 ..............


28-37-6 ...............


Date


Water
level


2-18-51 7.0
3-16-51 7.5
4-17-51 7.8
6- 8-51 8.0
7-22-51 8.9
10- 2-51 8.2
5- 4-52 7.3
6-21-52 7.1

12-11-52 3.65
2-12-53 2.57


Date


7-30-52
9-27-52
11- 8-52
12-29-52
2- 3-53
3-20-53
5-15-53
6- 3-53

4- 7-53
5-15-53


Water
level


7.0
8.1
8.2
8.3
8.1
7.0
7.1
8.3

- 4.83
- 5.68


i Water
Date I level
_ ________i____


7-23-53
9-17-53
10-13-53
12-17-53
6- 7-54
8-18-54
9-15-54
11- 9-54

6- 3-53
7-22-53


7.9
8.5
7.8
7.4
9.0
9.0
8.8
7.5

- 4.68
- 2.25


Date

12-23-54
1-31-55
3- 7-55
4- 4--55
6- 7-55
7-22-55
9-13-55
12-13-55

9-15-53
12- 9-53


Water
level

8.0
7.8
7.4
7.6
6.5
7.2
7.5
7.6

- 1.58
- 1.22


29-26-1............... 2-22-51 1.72 9-19-51 1.87 2- 4-53 0.44 10-15-53 2.65
3-16-51 1.80 7-24-52 .90 4- 1-53 4.20 12-15-53 2.50
4-11-51 0.67 10-11-52 1.88 5-16-53 5.49 3- 1-54 0.1
6- 6-51 3.37 11- 7-52 .74 7-22-53 1.09 9-21-54 2.9
8-22-51 2.69 12-29-52 1.84 9-17-53 2.75 6- 7-55 4.5

29-34-1............... 6-27-51 0.27 12-29-52 .58 7-23-53 1.02 9-16-54 2.40
7-29-52 1.23 2-11-53 1.20 9-17-53 2.49 9-28-54 2.75
11- 8-52 .70 5-30-53 2.63 12-15-53 1.73

29-36-3............... 11-13-52 4.5 7-22-53 3.67 8-18-54 3.0 6- 6-55 5.70
12-22-52 5.6 9-15-53 3.01 9-16-54 2.5 7-21-55 3.17
2-11-53 3.9 10-13-53 2.95 11- 9-54 4.0 9-15-55 3.04
3-31-53 6.9 12-15-53 3.07 12-23-54 3.4 10-27-55 3.98
5-15-53 -7.6 3- 2-54 8.2 1-31-55 3.8 12-13-55 4.05
6- 2-53 6.3 4-27-54 5.1 4- 4-55 4.2

30-39-19............... 6- 7-54 5.7 11- 9-54 8.5 2- 2-55 5.3 4- 4-55 6.5
8-18-54 5.1 12-23-54 -5.7 3- 7-55 9.3 5-13-55 9.5
9-15-54 5 .1 ............ ............ .. ..... ............ ............ ............
,, + "*


-1 1 1


Table 6 (continued)
..... .


,i


1




Table 6 (continued)

Water Water Water Water
Well No. Date level Date level Date level Date level
31-38-4............... 3-16-51 5.8 10- 2-51 5.6 3-20-53 5.6 8-18-54 7.5
6- 8-51 5.1 9-27-52 8.3 5-15-53 3.2 ........................
8- 9-51 7.1 12-11-52 5.6 9-15-53 8.5 ........................
9-19-51 8.3 2-11-53 8.3 12-16-53 8.8 ............ ............
32-29-3 ............... 6-22-52 2.05 5-16-53 3.90 10-15-53 5.0 6-28-54 5.0
7-29-52 3.20 7-21-53 3.57 12-10-53 5.05 8-23-54 5.2
2-11-53 3.6 9-17-53 5.09 2-25-54 0.9 9-17-54 4.6
4- 1-53 1.77 ............ ............ .... ................ ........... ............
32-30-1............... 9-20-54 10.05 2- 2-55 13.5 10-26-55 14.45 ........................
12-22-54 11.9 5- 9-55 18.9 12-15-55 13.37 ............ ............
35-26-1............... 9-20-54 11.5 4- 6-55 15.3 5-31-55 17.95 12-15-55 ............
3- 9-55 16.8 5- 9-55 20.6 10-26-55 14.80 ........................
35-33-6 ............... 2- 7-51 8.4 12-28-51 10.4 10-:0-52 9.8 7-21-53 9.8
4-16-51 10.8 4-10-52 7.0 12-29-52 7.5 9-14-53 10.7
6- 6-51 5.5 5- 4-52 4.34 2-10-53 10.5 10-14-53 10.1
8-23-51 11.9 7-29-52 12.0 4- 1-53 8-.0 12-17-53 9.6
9-26-51 11.5 9-15-52 11.2 5-15-53 4.9 2- 2-55 8.4
10- 2-51 11.3 10-11-52 10.2 6- 2-53 6.1 ............ ...........
36-29-2............... 12- 7-52 7.5 3-10-55 10.60 10-26-55 8.07 ........................
9-22-54 2.7 5-31-55 8.10 12-15-55 5.99 ........................
36-32-2 ............... 3-20-51 13.1 7-29-52 13.0 5-15-53 6.7 f 9-14-54 13.6
4-16-51 14.2 9-15-52 14.3 6- 2-53 8.0 9-28-54 15.5
6- 6-51 11.5 10-11-52 14.1 7-21-53 11.4 3- 9-55 9.0
8-15-51 14.1 10-20-52 12.1 9-14-53 14.1 5-31-55 11.6
5- 4-52 7.6 2-10-53 3.2 10-15-53 13.6...
6-26-52 11.3 4- 2-53 9.0 12-17-53 13.6 ........ .. .... ..










Table 6 (continued)


Water Water Water Water
Well No. Date level Date level Date level Date level

37-24-2............... 4-20-52 1.83 4- 1-53 -4.10 6-28-54 0.5 4-19-55 2.40
6-22-52 2.26 5-16-53 6.44 8-23-54 .7 5- 9-55 8.00
7-24-521.00 7-22-53 0.38 9-30-54 1.35 5-31-55 5.60
9-16-52 0.75 8-19-53 0.2 11-11-54 1.75 10-26-55 2.57
10-11-52 .25 9-17-53 1.05 12-21-54 .9 12-15-55 -3.64
12-11-52 1.79 12-15-53 1.20 2- 1-55 2.9 ........................
2-11-53.64 2-25-54 2.9 3-9-55 -5.15 ........................

38-32-9 ............... 3-20-51 1.2 10-11-52 14.1 3-2-54 14.7 2- 1-55 12.9
4-16-51 14.7 2-10-53 12.2 6-29-54 16.2 3- 9-55 11.7
6- 8-51 12.1 4-2-53 8.2 8-17-54 14.7 4- 4-55 13.9
8-18-51 13.5 5-15-53 9.5 9-14-54 12.6 5-13-55 9.9
9-25-51 7.9 6- 1-53 9.4 9-28-54 15.4 5-31-55 13.0
5- 4-52 8.0 7-21-53 15.3 11- 5-54 13.5 9-15-55 12.2
7-29-52 11.5 9-14-53 14.9 12-22-54 14.0 12-14-55 12.5
9-15-52 9.5 12-17-53 11.2 ............ ............ ........................
I I I


0



Lu'
0

0

C,,

Lu'
84






REPORT OF INVESTIGATIONS No. 18


TABLE 7. Logs of Selected Wells in Manatee County
Well 17-11-1
(Florida Geological Survey No. W-2595)
Del
Lithology Lai
Pleistocene and Pliocene:
Sand, clear, fine, quartz --.......------- ..--------......................---.......-...
Sand, dark brown, fine, with some coarse grains; contains carbonaceous
and limonitic material ("hardpan") ..----- ...------...-..-........ ..--------..
Sand, tan, fine ............. ..........----------------... -----.. -.. --..---........... ...------------...
Sand, brown, very fine; a few heavy mineral grains and some linmonite
Sand, tan, less stained than above, fine to medium ......------....---..----....... ...
Sand, darker tan than above, medium, with some fine and a few large
frosted pebbles; some sand is frosted and some is polished ......... .-.-
Sand, dark gray-brown, fine to medium; dark mineral grains, some
larger polished quartz grains ..................._ .................... ...................-----
Sand, dark tan, fine to medium,, with some rounded, frosted, and
polished pebbles; a few phosphate minerals; fragments of brown
sandstone .......-....----.......-----....--..........--...------.......--------.............................-------..............
Sand, lighter tan than above, fine to medium, with frosted and polished
pebbles of quartz; many dark gray pebbles of phosphate minerals ......
Sand, as above, but lighter in color and finer .----....... ...---- -----....-
Sand, as above, but dark gray-tan in color ....-....-.....................
Sand, as above, with some calcareous cement .. ..-- ---.............
Sand, gray, medium to coarse; much black phosphate minerals, fine to
pebble size; calcareous clay ................-----__......-..-- ....----
Sand and gravel of quartz and phosphate minerals; gray fairly hard,
sandy, silty limestone; shark tooth ..............---------.........--- --.. -----.
Hawthorn formation:
Sand and gravel of quartz and phosphate minerals; gray-green, silty,
calcareous, slightly sandy clay, with fine black and gray phosphate
minerals ............................-- -------------------------------.------------------..
As above, with fragments of gray-tan to dark gray limestone .....-----
Clay, greenish-gray and green, calcareous, sandy, phosphatic ......
Sand and gravel of quartz and phosphate minerals; dark gray, hard,
sandy limestone -------..-...-.........-- ---................- ---------...................... ...
Limestone, light to dark gray, hard, sandy; phosphate and quartz
pebbles; mollusk fragments -----....--.....----....--...........--...---....-------......-----......
Clay, light gray, chalky, sandy; limestone as above; quartz and
phosphate pebbles ..-........----------------. ------------- .. --------------
Clay, gray, silty, sandy, calcareous; fine-grained phosphate minerals;
impure limestone .---------.........................---..-. -----------------------.--
Limestone, gray to tan, hard, sandy, porous in part, crystalline in part,
fossiliferous; chert .........................................--- ....-....-....-.......----...-.......-----
Limestone, gray-white, fairly hard, crystalline in part, fossiliferous,
slightly sandy ....--- .--------- .......................---------- ...........----.------.......--
Limestone, as above; gray, calcareous, chalky, sandy clay; chert; sand;
phosphate minerals ...--......-------...--....................---...........................--..........------
Clay, as above; gray and tan, hard, dense limestone .............-.........
Clay, as above; gray-white, hard, sandy limestone, crystalline in part;
chert; phosphate minerals -....................................................................
Clay, dark gray-green, calcareous, silty, sandy; phosphate minerals;
limestone, as above .............................................---....-...---..--......--------..............
Clay, gray-white, chalky, sandy, with phosphate grains and pebbles;
white to tan, hard, sandy limestone; some chert .............................


pth Below
nd Surface
(feet)
0-8

8-10
10-15
15-20
20-25

25-40

40-50


50-00

60-65
65-70
70-75
75-80

80-90

90-95



95-105
105-125
125-129

129-135

135-144

144-155

155-170

170-180

180-196,

196-213
218-218

218-230

230-235


235-260







FLORIDA GEOLOGICAL SURVEY


Clay, gray, calcareous, sandy, with phosphate; tan and gray, hard,
sandy limestone; phosphate minerals and chert ..........------.--..................--------. 260-291
Limestone, white to tan, soft, fairly pure, fine, granular, fossiliferous;
chert and phosphate pebbles ....-------...--...-.....--.......................---------...... 291-300
Clay, white, chalky; tan, fairly soft, fossiliferous limestone, crystalline
in part; some chert ..- --- ...------.........----................----.--------... 300-306
Clay, dark green, silty, sandy, calcareous; white, gray, and tan, hard,
dense limestone, crystalline in part; chert ...-..........-...---........-------.....---...---. 306-317
Clay, reddish-tan, calcareous; tan and gray, hard, dense limestone, some
white, sandy; much dark brown chert -----.--.............------------....-. 8317-323
Clay, white, chalky; tan, hard, finely crystalline dolomitic, fossiliferous
limestone; chert; fine sand; phosphate minerals ....-------...---......---. 323-340
Clay, as above, with brown and gray chert .-------.. ..------..--.. ------ 840-345
Clay, gray and white, chalky, phosphatic; tan, finely crystalline, hard
limestone; some chert -------- ---..------....-.....-... 845-360
Clay, gray, sandy, chalky, phosphatic; white to tan, soft, sandy
limestone, porous in part, hard, dense, silicified, dolomitic in part,
fossiliferous in part ------------- -------- ------------------ 360-365
Clay, as above; white and gray, hard limestone, very sandy in part .. 8365-377
Clay andI limestone, as above; many shell fragments, ostracods, and
Foramlinif(era -............------------------------------ ----..---------.... 77-883
'l'anpa formation:
L[imtestone, white and gray, fragmental, fossiliferous .---- ....---.--..... 383-390
Limestone, white to tan, soft, sandy in part, porous; fine sand; shell
fragments, Foraminifera ---..---------------------.------------- 390-396
Limestone, gray, white and tan, hard, sandy, fossiliferous; contains
crystalline calcite, phosphate minerals, sand and chalcedony ..--------..... 896-400
Limlwstone, gray, white to tan, hard, very sandy, dolomitic in part,
porous in part; some chert; fossiliferous, mollusks, echinoid spines,
Sorits sp., and other Foraminifera .----.. ....--- .....------ .... ------ 400-443
LimestoIne, creamy white, soft, chalky, containing many Bryozoa, also
gray and tan, hard, sandy, fossiliferous .--..----.--.-----------... ..-----.. 448-456
Limestone, white, soft, chalky, sandy, fossiliferous; phosphate grains 456-464
Limestone, as above, with some dark gray, hard, sandy .---....---------........ 464-471
Limestone, liglit to dark gray, tan, hard, dense, very sandy, crystalline
and dolomitic in part; fossiliferous; some phosphate and chert ....-- 471-497
Lidmestonle, white, fairly soft, chalky, very sandy, fossiliferous; some
black phosplate grains; molds and casts of mollusks---- .-.....--.--..----.... 497-512
Clay, gray, green, waxy; fine sand; phosphate minerals; limestone, gray,
hard, dense, with fragments and pebbles of sandy limestone ..------.. 512-517
Limestone, white and tan, chalky, sandy, granular in part; chert and
chalcedony; mollusk molds and casts, and ostracods .......-------........------. 517-539
Clay, gray to tan, waxy, shaly, slightly sandy, calcareous; much very
fine phosphate, also some white, chalky, very sandy; a few limestone
fragments -- ..........-------------------- 539-544
Limestone, white, soft, chalky, very sandy; phosphate minerals; also
some tan, hard, dense limestone -...- -.----- ....................-------------------.-------- 544-578
Liimestone, as above; some chert .......---.-- .... .---.........------.. 578-582
Limestone, as above, fossiliferous .--- ..........-- -------------...............----------. 582-586
Limestone, as above, also tan and brown, hard, dense, less sandy,
fossiliferous; very little phosphate ... ....----...........-----------... 586-596
Limestone, gray, tan, and brown, hard, dense, sandy in part, porous in
part, fossiliferous; contains crystalline calcite .--.---...........-..-..--..-.........--------------.596-608
Limestone, as above, but more granular; Archaias floridanus present ..-- 608-612
No sample ---.. .. ----------------..-......... --- --....------..........................-.......... 612-624


90







REPORT OF INVESTIGATIONS No. 18


Suwannee limestone:
Limestone, creamy white and tan, fairly hard, granular, porous in part;
poorly preserved fossils, Rotalia mexicana, and other Foraminifera .... 624-631
Limestone, white to tan, soft, pure, granular, porous, fossiliferous;
abundant echinoid spines and plates, Rotalia mexicana, and other
Foraminifera --...----................---......--------------------..........................---.-----........-................-----.... 631-720
Limestone, as above, but darker tan and more crystalline; fewer
F oraminifera --........-.....................--..---....................--...........--------------------------.............---.. 720-767
Limestone, as above, but less granular ..------..-----..--........-----.........-----..............--...... 767-773
Ocala group:
Limestone, gray-tan, "dirty" appearing, fairly soft, somewhat granular,
fossiliferous ..............................................................----........................... 773-783
Limestone, gray, tan, fairly hard to soft, granular to fragmental,
crystalline in part, fossiliferous; many Foraminifera, including
Gyipsina globula ................................-------...-----.......--.-------------...............----. 783-805
Limestone, as above, with Lepidocyclina floridensis, L. ocalana, Iletero-
stegina ocalana, Operculinoides sp. ..------.........--..-.--.--....................------...---....---..... 805-831
Limestone, gray to tan; foraminiferal coquina with a fine granular
chalky matrix, Nummulites sp., Gypsina globula, Lepidocyclina
ocalana, Operculinoides floridensis, Heterostegina ocalana .--..............-------- 831-930
Limestone, as above; gray-tan, sticky, calcareous clay ...........-- ............. 930-937
Limestone, as above, and brown, hard, crystalline dolomite ...--...----- 937-955
Limestone, dark brown, saccharoidal, dolomitic; some fragments are
white, fairly soft ..........-....-....-----..-..-..--..--.........................---------.------....-----...----. 955-974
Limestone, as above, but porous ....--....---.......-------------..... ----..--... 974-981
Limestone, as above, but lighter in color ...--...---.. -------..---------... 981-987
Limestone, as above, but gray-tan in color ------..-.. --.... ---- .--.. ...-..---..-. 987-1,051
Limestone, dark brown, saccharoidal, dolomitic; some fragments are
white and gray -..-...-----------.. -----------........ ------...-------...... 1,051-1,068
Limestone, as above, also tan, fairly hard, dense, some granular, porous
in part, fossiliferous; contains mollusks, echinoids, ostracods,
Foraminifera, Gypsina globula, Nummulites sp., and others .......---... 1,063-1,089
Limestone, gray and tan, hard, dense, dolomitic in part, crystalline in
part, has chalky matrix; mollusks, echinoids, Foraminifera .-------- 1,089-1,097
Avon Park limestone:
Limestone, tan, fairly soft, granular, chalky, crystalline calcite,
echinoids, ostracods, Dictyoconus cooked, and other Foraminifera .-.1,097-1,112
Limestone, as above, also porous, foraminiferal; abundant Dictyoconus
cooker, ostracods, echinoids ........ .......------.------........ ...------.------..-.....-- 1,112-1,136
Limestone, creamy white and tan, soft, granular with a chalky matrix,
foraminiferal, crystalline in part; Dictyoconus cooked, Lituonella
floridanus, Valvulina sp., and other Foraminifera .......-------------.... ... 1,136-1,151
Limestone, white and tan, soft, chalky, granular, porous, foraminiferal;
Dictyoconus cooked, Spirolina coryensis, Valvulina sp., and others ..-1,151-1,246
Limestone, as above, but with fewer fossils; also brown hard crystalline
dolomite ---------...-......... ............... .........-------............------ ------- ......----..... 1,246-1,253
Limestone, creamy white to gray-white and tan, hard, dense to
granular, chalky, fossiliferous; some brown crystalline dolomite;
Dictyoconus cooked, and others ..--.--...........-........---.......-----.-------..........--..... 1,253-1,275
Limestone, as above, fossils fewer and poorly preserved ..-- ---......----...1,275-1,301
Limestone, as above, but more fossiliferous ..........-.....-..-..--....--.------............ 1,301-1,330
Limestone, dark tan and gray, hard, dense, nodular, porous in part,
fossiliferous; Dictyoconus cooked, and others --..........-...----.........--.......----..-....--. 1,8830-1,376
Limestone, as above; dolomite, dark brown, crystalline, porous -----.......... 1,376-1,418