U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 01-4084

Prepared in cooperation with the

SOUTH FLORIDA WATER MANAGEMENT DISTRICT

Surface-Geophysical Characterization of

Ground-Water Systems of the

Caloosahatchee River Basin, Southern Florida
Surface-Geophysical Characterization of Ground-Water 

Systems of the Caloosahatchee River Basin, 

Southern Florida

By Kevin J. Cunningham, Stanley D. Locker, Albert C. Hine, 

David Bukry, John A. Barron, and Laura A. Guertin

U.S. Geological Survey

Water-Resources Investigations Report 01-4084

Prepared in cooperation with the

SOUTH FLORIDA WATER MANAGEMENT DISTRICT

Tallahassee, Florida

2001
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

CHARLES G. GROAT, Director

Use of trade, product, or firm names in this publication is for descriptive purposes only 

and does not imply endorsement by the U.S. Geological Survey

For additional information Copies of this report can be 

write to: purchased from:

District Chief U.S. Geological Survey

U.S. Geological Survey Branch of Information Services

Suite 3015 Box 25286

227 N. Bronough Street Denver, CO 80225

Tallahassee, FL 32301 888-ASK-USGS

Additional information about water resources in Florida is available on the World 

Wide Web at http://fl.water.usgs.gov
Contents III

CONTENTS

Abstract ............................................................................................................................................................................... 1

Introduction ......................................................................................................................................................................... 2

Purpose and Scope .................................................................................................................................................... 2

Previous Studies ........................................................................................................................................................ 2

Acknowledgments..................................................................................................................................................... 4

Methods............................................................................................................................................................................... 4

Seismic-Reflection Survey........................................................................................................................................ 4

Ground-Penetrating Radar......................................................................................................................................... 4

Drilling, Well Completion, Geophysical Logging, and Core Analysis..................................................................... 6

Micropaleontology .................................................................................................................................................... 7

Strontium-Isotope Stratigraphy ................................................................................................................................. 7

Hydrogeologic Framework ................................................................................................................................................. 7

Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin........................................... 8

Marine Seismic-Reflection Survey ........................................................................................................................... 8

Survey Segment 1............................................................................................................................................ 8

Survey Segment 2.......................................................................................................................................... 14

Survey Segment 3.......................................................................................................................................... 19

Survey Segment 4.......................................................................................................................................... 22

Survey Segment 5.......................................................................................................................................... 28

Ground-Penetrating Radar....................................................................................................................................... 28

Indian Mound Site......................................................................................................................................... 28

CRS06 Site .................................................................................................................................................... 30

Summary and Conclusions................................................................................................................................................ 33

References Cited ............................................................................................................................................................... 34

Appendix: Lithologic Descriptions of Cores Drilled for this Study ................................................................................. 37

FIGURES

1. Map of the Caloosahatchee River Basin study area showing locations of seismic illustrations, test coreholes

drilled for this study, seepage meter sites, ground-penetrating radar sites, and established test wells .................... 3

2. Column showing lithostratigraphic units recognized in the study area, their generalized geology, and

relation with hydrogeologic units............................................................................................................................. 5

3. Interpretive line drawing based on marine seismic-reflection profiles along the Caloosahatchee River from

structures S-77 to S-79 ............................................................................................................................................. 9

4. Seismic-reflection profile between Ortona Lock and Moore Haven...................................................................... 10

5. Hydrogeologic section A-A′ showing test coreholes drilled for this study near the Caloosahatchee River.......... 13

6. Column showing correlation of the chronostratigraphy of part of the late Tertiary geomagnetic polarity

time scale ................................................................................................................................................................ 17

7. Seismic-reflection profile between La Belle and Ortona Lock showing strata drilled at the GL-323 

test corehole............................................................................................................................................................ 18

8. Seismic-reflection profile between La Belle and the GL-323 test corehole .......................................................... 20

9. Seismic-reflection profile between La Belle and S-79 (Franklin Lock) ................................................................ 27

10. Seismic-reflection profile in San Carlos Bay ......................................................................................................... 29

11. Ground-penetrating radar profile and interpretation from the Indian Mound site in Glades County .................... 31

12. Sections showing correlation of ground-penetrating radar profile, test corehole HE-1118, and seepage 

meters at the CRS06 monitoring well site in Hendry County ................................................................................ 32

13. Plot showing average ground-water seepage data collected at the CRS06 monitoring well site in Hendry

County, October 1998 to January 1999 .................................................................................................................. 33
IV Contents

TABLES

1. Description of wells drilled during this study ................................................................................................................ 6

2. Occurrence of stratigraphically important silicoflagellate taxa in test coreholes GL-327 and GL-329 .......................11

3. Strontium-isotope data and ages from shell material collected from test coreholes GL-323, GL-325, 

GL-327, and L-5809..................................................................................................................................................... 14

4. Occurrence of stratigraphically important coccolith taxa in test coreholes GL-323, GL-325, GL-327, 

and GL-329 .................................................................................................................................................................. 15

5. Occurrence of stratigraphically important diatom taxa in test coreholes GL-323, GL-325, GL-327, 

and GL-329 .................................................................................................................................................................. 21

6. Benthic foraminiferal genera listed alphabetically and their distribution with depth in test coreholes GL-323, 

GL-325, GL-327, GL-329, and L-5809 ....................................................................................................................... 23

7. Ecological data for benthic foraminiferal genera identified in test coreholes GL-323, GL-325, GL-327, 

GL-329, and L-5809..................................................................................................................................................... 26

Conversion Factors, Acronyms, and Abbreviations

Multiply By To obtain

inch (in.) 25.4 centimeter (cm)

foot (ft) 0.3048 meter (m)

foot per second (ft/s) 0.3048 meter per second (m/s)

foot per day (ft/d) 0.3048 meter per day (m/d)

foot per nannosecond (ft/ns) 0.3048 meter per nannosecond (m/ns)

mile (mi) 1.609 kilometer (km)

mile per hour (mi/hr) 1.609 kilometer per hour (km/hr)

square mile (mi2) 2.590 square kilometer (km2)

Acronyms

FGS Florida Geological Survey

GPR Ground-penetrating radar

SFWMD South Florida Water Management District

SRM Standard reference material

USGS U.S. Geological Survey

Abbreviations

Hz Hertz

J Joule

Ma Million years

MHz Megahertz

ms Millisecond

ns Nannosecond

Vp Compressional wave velocity
Abstract 1

Surface-Geophysical Characterization of Ground-Water 

Systems of the Caloosahatchee River Basin, 

Southern Florida

By Kevin J. Cunningham1, Stanley D. Locker2, Albert C. Hine2, David Bukry3, 

John A. Barron3, and Laura A. Guertin4

Abstract

The Caloosahatchee River Basin, located in 

southwestern Florida, includes about 1,200 square 

miles of land. The Caloosahatchee River receives 

water from Lake Okeechobee, runoff from the watershed, and seepage from the underlying ground-water 

systems; the river loses water through drainage to the 

Gulf of Mexico and withdrawals for public-water 

supply and agricultural and natural needs. Water-use 

demands in the Caloosahatchee River Basin have 

increased dramatically, and the Caloosahatchee could 

be further stressed if river water is used to accommodate restoration of the Everglades. Water managers 

and planners need to know how much water will be 

used within the river basin and how much water is 

contributed by Lake Okeechobee, runoff, and ground 

water.

In this study, marine seismic-reflection and 

ground-penetrating radar techniques were used as a 

means to evaluate the potential for flow between the 

river and ground-water systems. Seven test coreholes 

were drilled to calibrate lithostratigraphic units, their 

stratal geometries, and estimated hydraulic conductivities to surface-geophysical profiles. 

A continuous marine seismic-reflection survey 

was conducted over the entire length of the Caloosahatchee River and extending into San Carlos Bay. 

Lithostratigraphic units that intersect the river bottom 

and their characteristic stratal geometries were 

identified. Results show that subhorizontal reflections 

assigned to the Tamiami Formation intersect the river 

bottom between Moore Haven and about 9 miles 

westward. Oblique and sigmoidal progradational 

reflections assigned to the upper Peace River Formation probably crop out at the floor of the river in the 

Ortona area between the western side of Lake 

Hicpochee and La Belle. These reflections image a 

regional-scale progradational deltaic depositional 

system containing quartz sands with low to moderate 

estimated hydraulic conductivities. In an approximate 6-mile length of the river between La Belle and 

Franklin Lock, deeper karstic collapse structures are 

postulated. These structures influence the geometries 

of parallel reflections that intersect the river channel. 

Here, reflections assigned to the Buckingham Limestone Member of the Tamiami Formation (a confining 

unit) and reflections assigned to the clastic zone of 

the sandstone aquifer likely crop out at the river 

bottom. Beneath these shallow reflections, relatively 

higher amplitude parallel reflections of the carbonate 

zone of the sandstone aquifer are well displayed in 

the seismic-reflection profiles. In San Carlos Bay, 

oblique progradational reflections assigned to the 

upper Peace River Formation are shown beneath the 

bay. Almost everywhere beneath the river, a diffuse 

ground-water flow system is in contact with the 

channel bottom. 

Ground-penetrating radar profiles of an area 

about 2 miles north of the depositional axis of the 

deltaic depositional system in the Ortona area show 

that progradational clinoforms imaged on seismic 

reflection profiles in the Caloosahatchee River are 

present within about 17 feet of the ground surface. 1U.S. Geological Survey, Miami, Fla.

2University of South Florida, Tampa, Fla.

3U.S. Geological Survey, Menlo Park, Calif.

4Mary Washington College, Fredricksburg, Va.
2 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

Ground-penetrating radar profiles show southward 

dipping, oblique progradational reflections assigned 

to the upper Peace River Formation that are terminated at their tops by a toplapping or erosional 

discontinuity. These clinoformal reflections image 

clean quartz sand that is probably characterized by 

moderate hydraulic conductivity. This sand could be 

mapped using ground-penetrating radar methods.

INTRODUCTION

The Caloosahatchee River Basin is located in 

southwestern Florida and includes approximately 

1,200 mi2 of land (LaRose and McPherson, 1980). 

The Caloosahatchee River receives water from Lake 

Okeechobee, runoff from the watershed, and seepage 

from the surficial aquifer system. The river empties 

into the Gulf of Mexico behind Sanibel and Pine 

Islands near Fort Myers (fig. 1), and supplies water 

for public, agricultural, and natural needs. Water-use 

demands in the Caloosahatchee River Basin have 

increased dramatically and could be further stressed if 

used to accommodate restoration of the Everglades 

(Dabbs, 1998). To determine how much water, if any, 

can be diverted for restoration, water managers and 

planners need to know how much water will be used 

within the river basin, and how much water is contributed to the river by Lake Okeechobee, runoff, and 

ground water. An integrated surface-water/groundwater model is being used by the South Florida Water 

Management District (SFWMD) to develop a water 

budget for the Caloosahatchee River Basin based on 

current usage in order to predict the effects of watermanagement alternatives (Dabbs, 1998). To better 

assess the hydraulic connection between the Caloosahatchee River and the underlying aquifer systems used 

in the model, the U.S. Geological Survey (USGS), in 

cooperation with the SFWMD, initiated a study to 

provide a high-resolution geophysical and hydrogeologic framework for the aquifer systems underlying 

the Caloosahatchee River Basin.

Purpose and Scope

The purpose of this report is to characterize the 

hydrogeologic framework of ground-water systems 

that are being simulated by the integrated groundwater/surface-water model for the Caloosahatchee 

River Basin. This is accomplished through the interpretation of geophysical, lithologic, micropaleontological, 

and strontium-isotope data.

Depth to geologic contacts and hydrogeologic 

units, orientation of bedding, lithologic types and 

thickness, and sequence stratigraphy are interpreted 

from seismic-reflection and ground-penetrating radar 

(GPR) profiles. Lithologic descriptions of seven test 

coreholes are linked to the geophysical interpretations 

to provide an accurate hydrogeologic framework. 

Micropaleontologic and strontium-isotope data provide 

temporal constraints that guide correlation of reflections 

on seismic profiles and of lithologic units in cores.

Previous Studies

Few surface-geophysical surveys have been 

collected in the area of the Caloosahatchee River 

Basin. Missimer and Gardner (1976) demonstrated the 

benefits of linking the hydrology of Lee County, Fla., 

to subsurface geologic features on seismic profiles, 

including lithostratigraphic boundaries, bedding orientation, paleochannel-fills, and lithology. Wolansky and 

others (1983) correlated seismic-stratigraphic units to 

the hydrologic units of the surficial and intermediate 

aquifer systems in an area including Charlotte Harbor 

and Venice in southwestern Florida. Lewelling and 

others (1998) showed how seismic-reflection data can 

contribute to the identification of geologic features that 

could act as potential conduits for the exchange of surface water in the Peace River and underlying aquifers 

in west-central Florida. About 8 mi of single-channel 

and multichannel airgun data have been collected on 

the inland river section of the Caloosahatchee River 

and about 5.5 mi in the Caloosahatchee River estuary 

and San Carlos Bay (Scholz and Cunningham, 1997). 

Specific hydrogeologic features that can be inferred 

from GPR profiles include sediment types and thickness 

(Beres and Haeni, 1991), karst features (Barr, 1993; 

McMechan and others, 1998), subaerial-exposure 

surfaces (Kruse and others, 2000), depth to water table 

and clay beds (Johnson, 1992; Barr, 1993), and soil 

types and soil conditions (Freeland and others, 1998). 

Finally, van Overmeeren (1998) showed the application of linking radar stratigraphy to hydrogeological 

characteristics of the shallow subsurface.
Introduction 3

Ok

Lake

Hicpochee

San

Carlos

Bay

LEE COUNTY

HENDRY COUNTY

COLLIER COUNTY

CHARLOTTE COUNTY

GLADES COUNTY



	 
	  	 




	



S-77

S-79

S-78

EXPLANATION

Indian

Mound

CRS06

GL-323

GL-325

HE-1118

L-5809

GL-324

W-17591

GULF OF MEXICO

GL-326

00

15 MILES

15 KILOMETERS

5 10

5 10

SEGMENT 5

SEGMENT 4 SEGMENT 3 SEGMENT 2

SEGMENT 1

Sanibel

Pine

Island

Island

Fort

Myers

La Belle

Canal C-43 GL-329

GL-327

W-16944

W-12844

A

A

S-79CRS06L-5809W-17591

GROUND-PENETRATING RADAR SURVEY SITE NAME ORNUMBER--Four seepage meters are located at the CRS06 siteCONTROL STRUCTURE NAME AND NUMBERNON-U.S. GEOLOGICAL SURVEY TEST WELL AND NUMBER

SEISMIC PROFILEROADSAND PITHYDROGEOLOGIC SECTION

U.S. GEOLOGICAL SURVEY TEST COREHOLE AND NUMBER--Test

coreholes GL-326 and HE-1118 drilled to support ground-penetratingradar data. Other test coreholes drilled to assist the seismic-reflection

A A survey. Test well GL-324 is a monitor well drilled by rotary method 

Caloosahatchee

River

29

82

884

41 846

41

75

Figure 1. The Caloosahatchee River Basin study area showing locations of seismic illustrations, test coreholes drilled for this study, sepenetrating radar sites, and established test wells. Continuous seismic surveys were run from S-77 at Lake Okeechobee to the bridge crCarlos Bay at the Gulf of Mexico. Segments 1-5 are areas on seismic profiles exhibiting different seismic stratigraphic characteristics.
4 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

Acknowledgments

Pamela Telis of the USGS is acknowledged for 

providing technical support for this investigation. 

Jim Trindell of the Florida Geological Survey (FGS) 

drilled seven test coreholes. Tom Scott (FGS) contributed 

to the organization of the drilling program. Anthony 

Brown and Steven Memberg (USGS) provided assistance in geophysical logging of wells. Marc Buursink 

(USGS) gave long-distance assistance with the GPR 

instrumentation. The x-ray diffraction determinations 

were conducted by Donald McNeill (University of 

Miami). 

METHODS

A multidisciplinary approach was taken to 

produce an accurate high-resolution hydrogeologic 

framework of the ground-water systems underlying 

the Caloosahatchee River Basin. This approach 

included the integration of marine seismic-reflection 

techniques, GPR methods, core analyses, micropaleontology, and strontium-isotope stratigraphy.

Seismic-Reflection Survey

About 180 mi of digital, single-channel, marine 

seismic-reflection data were collected along much of 

the Caloosahatchee River and part of San Carlos Bay 

(fig. 1). Good seismic penetration was achieved to 

more than 250 ms or about 800 ft during the survey. 

Problems with intense acoustic reverberations generated at the river floor prevented meaningful imaging in 

parts of the seismic survey. Muddy sediments or gas, 

especially in freshwater environments, can contribute 

to reverberations (Snyder and others, 1989; Evans and 

others, 1994). The obscured penetration was localized 

and sometimes not present across the full width of the 

river. For the section of river between structures S-79 

and S-77 (fig. 1), lines were run on opposite sides of 

the river during traverses upstream and downstream so 

that the double coverage could avoid some of the 

localized problems caused at the river bottom.

The seismic-reflection survey was collected 

using an Elics Delph2 digital acquisition and processing system. A Huntec electrodynamic “boomer” plate 

attached to a catamaran sled was used to generate the 

underwater acoustical pulse. This acquisition unit was 

powered by an Applied Acoustics CSP-1000 power 

supply at a setting of 700 or 1,000 J. The shot rate 

was 1 second with a sampling rate of 8,000 Hz. 

An Innovative Transducer ST-5 10-channel hydrophone array was used to detect the return pulse. 

The range of the recording window was from 0 to 

300 ms. Real-time navigational positions were 

obtained using Trimble digital global positioning system equipment. Post-cruise data processing included 

bandpass filtering, automatic gain control, and trace 

summing. 

For seismic data at and close to test coreholes 

GL-323, GL-325, GL-327, GL-329, and L-5809 

(fig. 1), approximate depth scales for seismic profiles 

were calculated from two-way traveltimes using velocities of 5,315 ft/s above the top of the lower Peace 

River Formation (fig. 2) and 8,203 ft/s below the top of 

the lower Peace River Formation. These velocities are 

based on correlation of test-corehole data to seismic 

profiles. The velocities above the top of the lower 

Peace River Formation are lower than velocities 

reported for similar facies (quartz sand) by Anselmetti 

and others (1997). For seismic profile illustrations 

herein that do not include test coreholes, approximate 

depth scales were calculated using a Vp of 5,578 ft/s 

above the top of the lower Peace River Formation and 

7,218 ft/s below the top of the lower Peace River 

Formation. These velocities are more consistent with 

the laboratory measurement of Anselmetti and others 

(1997). Description and interpretation of seismicreflection configuration patterns are based on comparison to examples in Mitchum and others (1977).

Ground-Penetrating Radar

The surface-geophysical method of GPR was 

used to obtain continuous images of geologic and 

hydrogeologic units at two sites in the Caloosahatchee 

River Basin. The Indian Mound and CRS06 sites were 

chosen for detailed interpretation, owing to the superior 

quality of the GPR profiles (fig. 1).

All GPR data were collected using a SIR System-10A+ with a dual 100-MHz antenna array manufactured by Geophysical Survey Systems, Inc. The 

profiles were collected by towing the antennas 55 ft 

behind a truck with a connecting rope and cable at a 

rate of about 0.5 mi/hr. The separation between the 

center point of the antennas was 35 in. Interpretations 

were made using RADAN for WinNT software and the 

RADAN-to-bitmap conversion utility.

At the Indian Mound site, approximate depth 

scales for radar profiles were calculated from two-way 
Methods 5

Series Lithostratigraphic

units (this study)

HOLOCENE

PLEISTOCENE

MIOCENE

OLIGOCENE

UNDIFFERENTIATED

LAKE FLIRT MARL,

UNDIFFERENTIATED

SOIL AND SAND

PAMLICO

SAND

FORT

THOMPSON

FORMATION

CALOOSAHATCHEE

FORMATION

BUCKINGHAM

LIMESTONE

MEMBER

UNNAMED

SAND

OCHOPEE

LIMESTONE

MEMBER

LOWER

PEACE

RIVER

FORMATION

ARCADIA

FORMATION

SUWANNEE

LIMESTONE

UPPER

PEACE

RIVER

FORMATION

TAMIAMI FORMATION HAWTHORN

GROUP

Lithology

Hydrogeologic

units

(Reese and

Cunningham,

2000)

South Florida Water

Management District

hydrogeologic

units

INTERMEDIATE

AQUIFER SYSTEM

INTERMEDIATE

CONFINING UNIT

SANDSTONE

AQUIFER

CLASTIC

ZONE

CARBONATE

ZONE

UPPER

HAWTHORN

CONFINING ZONE

UPPER

FLORIDAN

AQUIFER

UPPER

FLORIDAN

AQUIFER

MID-HAWTHORN

CONFINING ZONE AND

AQUIFER AND LOWER

HAWTHORN CONFINING

ZONE

SURFICIAL AQUIFER SYSTEM

UPPER

SEMICONFINING

TO CONFINING

UNIT

TAMIAMI

CONFINING

ZONE

GRAY

LIMESTONE

AQUIFER

LOWER

TAMIAMI

AQUIFER

Marl, quartz sand,

peat, organic soil

Quartz sand

Marine limestone and minor

gastropod-rich freshwater limestone

Quartz sand, pelecypod-rich

quartz sandstone, terrigenous

mudstone

Pelecypod rudstone and float

stone, quartz sand rich, locally

marly

Pelecypod lime rudstone

and floatstone, pelecypod-rich

quartz sand, moldic quartz

sandstone

Quartz sand, sandstone, and

pelecypod-rich quartz sand,

local abundant phosphate grains

diatomaceous mudstone,

Moldic pelecypod-rich

quartz sand or sandstone

Marl, clay, phosphate

grains, quartz sand

Limestone, dolosilt, quartz sand,

terrigenous mudstone, local

abundant phosphate grains

Sandy limestone, dolomite,

phosphatic sand and carbonate,

sand, silt, and clay

Fossiliferous

limestone

WATERTABLE

AQUIFER WATERTABLE

AQUIFER

PLIOCENE

Figure 2. Lithostratigraphic units recognized in the study area, their generalized geology, and relation with hydrogeologic 

units. Modified from Olsson and Petit (1964), Hunter (1968), Wedderburn and others (1982), Miller (1986), Smith and Adams 

(1988), Missimer (1992), Brewster-Wingard and others (1997), Missimer (1997; 1999), Weedman and others (1999), and 

Reese and Cunningham (2000).
6 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

traveltimes employing velocities of 0.49 ft/ns for 

unsaturated sand and 0.20 ft/ns for saturated sand 

(Davis and Annan, 1989). At the CRS06 site, velocities 

were calculated using depths to reflections that could 

be determined from positive correlations with a buried 

culvert, depth to water table, and test-corehole lithologies. The velocity of unsaturated sand was calculated 

at 0.39 ft/ns using a traveltime from ground level to 

the measured depth of an exposed metal culvert. The 

velocity of saturated sand was calculated at 0.24 ft/ns, 

the traveltime between the measured top of the water 

table and the measured depth to the top of limestones 

of the Caloosahatchee Formation (fig. 2). A velocity 

of 0.18 ft/ns was used for saturated limestone. This 

value was obtained from Kruse and others (2000) for 

saturated near-surface limestones in southern Florida.

Drilling, Well Completion, Geophysical 

Logging, and Core Analysis

Seven continuous test coreholes (fig. 1) were 

drilled to groundtruth seismic-reflection and GPR surveys. The test coreholes were drilled by the FGS using 

a Failing 1500 drilling rig that employs a wireline coring method. Five of the test coreholes are located in 

Glades County (GL-323, GL-325, GL-326, GL-327, 

and GL-329), one in Lee County (L-5809), and one in 

Hendry County (HE-1118) as shown in figure 1. 

The GL-326 and HE-1118 test coreholes were drilled 

to support the GPR data, whereas the other coreholes 

were drilled to support interpretation of the seismicreflection survey. Three test coreholes (GL-325, 

GL-327, and L-5809) were constructed as monitoring 

wells using 2-in. diameter slotted, polyvinyl-chloride 

casing. An additional monitoring well (GL-324) was 

drilled by normal rotary method at a distance of 10 ft 

from test corehole GL-323 (fig. 1). Descriptions of the 

test coreholes and a normal-rotary well drilled for this 

study are given in table 1.

Borehole-geophysical logs collected by the 

USGS for six of the test coreholes drilled during this 

study include induction resistivity, natural gamma ray, 

spontaneous potential, and single-point resistance. 

The induction-resistivity log was not collected at well 

GL-323 because of operational problems with the 

borehole-geophysical tool, and no logs were run in 

well GL-329 because of the shallow collapse of the 

wellbore. Borehole-geophysical tools were run in 

holes filled with drilling mud and cased with 6-in. 

diameter steel surface casing set to a depth between 

10 and 25 ft below ground level. The data were 

collected in digital format and are archived at the 

USGS office in Miami, Fla. 

Table 1. Description of wells drilled during this study

[Well locations are shown in figure 1. USGS, U.S. Geological Survey; FGS, Florida Geological Survey; MW, monitoring well; WLC, wireline 

core; NA, not applicable; NR, normal rotary; PVC, polyvinyl chloride; TW, test well]

Well identifier

Well 

type

Drilling 

method

Land net 

location

Lati-

 tude1

Longi-

 tude1

Altitude of 

measuring 

point2

(feet)

Total 

depth 

drilled 

(feet)

Well construction 

material

Screen interval

USGS 

local well 

number 

FGS

Depth at 

top 

(feet)

Depth at

bottom

(feet)

Sand

pack

GL-323 W-18069 TW WLC SE SEC25 

T42S R29E

 264738 0812142 21 401 NA NA NA NA

GL-324 NA MW NR SE SEC25 

T24S R29E

 264738 0812142 21 38 2-inch PVC 20 37 6/20

GL-325 W-18070 TW, 

MW

WLC NW SE SEC35

T42S R29E

 264622 0812338 25.5 200.75 2-inch PVC 25 55 6/20

GL-326 W-18073 TW WLC SW SW SEC30

T42S R32E

 264659 0811017 16 39.5 NA NA NA NA

GL-327 W-18074 TW, 

MW

WLC SW SEC22 

T42S R32E

264803 0810705 14 454 2-inch PVC 40 100 20/30

GL-329 W-18075 TW WLC SW SW SEC25 

T42S R31E

264707 0811114 34 431 NA NA NA NA

HE-1118 W-18072 TW WLC NE SEC19 

T43S R31E

 264408 0811555 22 26.75 NA NA NA NA

L-5809 W-18071 TW, 

MW

WLC NE SEC26 

T43S R27E

 264257 0813527 8 100 2-inch PVC 41 61 6/20

1North American Datum of 1983.

2Ground level.
Hydrogeologic Framework 7

 Core samples were described in the laboratory 

using a 10-power hand lens and binocular microscope 

to determine vertical patterns of microfacies, sedimentary structures, lithostratigraphic boundaries and to 

estimate hydraulic conductivity. Core-sample descriptions are presented in the appendix. Limestones were 

classified by combining the schemes of Dunham 

(1962), Embry and Klovan (1971), and Lucia (1995). 

Rock colors were recorded by comparing dry samples 

to a rock-color chart containing Munsell color chips 

(Geological Society of America, 1991). Hydraulic conductivity of cores was visually estimated using a classification scheme based on local lithologies and physical 

properties of sediments developed by Fish (1988, table 7). 

This scheme distinguishes five categories of hydraulic 

conductivity for lithologies within the surficial aquifer 

system in Broward County: very high is greater than 

1,000 ft/d, high ranges from 100 to 1,000 ft/d, moderate ranges from 10 to 100 ft/d, low ranges from 0.1 to 

10 ft/d, and very low to nearly impermeable is less than 

0.1 ft/d.

Micropaleontology

Coccoliths and diatoms were prepared and identified using standard methods at the USGS Micropaleontology Laboratory in Menlo Park, Calif. Coccolith 

floras were assigned to the biostratigraphic zones of 

Okada and Bukry (1980) with normalized additions of 

Subzones CN12aA, aB, and aC from Bukry (1991). 

Diatom floras were dated using the correlations of Barron 

(1992). Ages are reported in accordance with the integrated magnetobiochronologic Cenozoic time scale of 

Berggren and others (1995).

Information contained in Bock and others 

(1971), Poag (1981), and Jones (1994) was used to help 

identify benthic foraminifera at the genus level. Paleoenvironmental interpretations are based on Murray’s 

(1991) grouping of individual benthic foraminiferal 

associations and species into broad depth categories of 

inner and outer shelf, which are defined as mean sea 

level to approximate water depths of 330 ft and 330 to 

660 ft, respectively. 

Strontium-Isotope Stratigraphy

Thirteen pelecypod shells and one echinoderm 

shell that appeared to be unaltered, based on examination with a binocular microscope, were collected from 

test coreholes GL-323, GL-325, and L-5809 for 

strontium-isotope analysis. Five samples were 

collected from the Arcadia Formation, six samples 

from the Peace River Formation, and three samples 

from the Tamiami Formation. Chemical separations 

and isotopic analyses were conducted by the Thermal 

Ionization Mass Spectrometry Laboratory at the 

University of Florida in Gainesville. The x-ray diffraction analyses showed that all samples were composed 

of low-magnesium calcite. The within-run precision 

for single analyses ranged from 10 to 21 x 10-6 (2σ

standard error from the mean). All strontium-isotopic 

ratios were normalized to 86Sr/88Sr = 0.1194 and to 

SRM-987 = 0.710249 with a 2σ error of 23 x 10-6. 

Conversion of 87Sr/86Sr values to ages was derived 

from “Look-up Table Version 3:10/99” of Howarth and 

McArthur (1997). A value of 1 x 10-6 was subtracted 

from all 87Sr/86Sr values to correct for an interlaboratory bias between the University of Florida values and 

data presented in the “Look-up Table” of Howarth and 

McArthur (1997). The ages are used in accordance 

with the integrated magnetobiochronologic Cenozoic 

time scale of Berggren and others (1995).

HYDROGEOLOGIC FRAMEWORK

This study focused on the surficial aquifer 

system and the intermediate aquifer system or 

intermediate confining unit (fig. 2) underlying the 

study area. The surficial aquifer system consists of the 

water-table aquifer and hydraulically connected units 

above the first occurrence of laterally extensive beds of 

much lower permeability. The surficial aquifer system 

is composed mainly of sediments and rocks of 

Pliocene age (Tamiami Formation) and of Pleistocene 

and Holocene ages (fig. 2). The surficial aquifer 

system is divided into two aquifers: the water-table 

aquifer and the gray limestone aquifer, also called the 

lower Tamiami aquifer (Smith and Adams, 1988; 

Reese and Cunningham, 2000). The Ochopee 

Limestone is included in the gray limestone aquifer of 

southern Florida; this major aquifer was defined by 

Fish (1988) and investigated over a broad area by 

Reese and Cunningham (2000). The water-table 

aquifer and the gray limestone aquifer are either 

separated by a semiconfining to confining unit or 

coincide where confinement is absent (Knapp and 

others, 1984; Smith and Adams, 1988; Reese and 

Cunningham, 2000).
8 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

The intermediate aquifer system includes 

permeable rock and sediment that lie between the surficial aquifer system and the Floridan aquifer system; 

however, the intermediate aquifer system acts as a 

confining unit to the Floridan aquifer system in the 

study area. The intermediate aquifer system occurs 

within the Hawthorn Group and is composed mostly 

of a heterogeneous mixture of low-permeability clay, 

sandy clay, and dolosilt. Zones of permeable limestone, dolostone, sandstone, sand, and gravel also 

occur in this aquifer system. The intermediate aquifer 

system has been divided by the SFWMD into the 

sandstone aquifer, which lies between the upper 

Hawthorn confining zone and the mid- and lower 

Hawthorn confining zones; the sandstone aquifer is 

composed of a clastic and carbonate zone (Smith and 

Adams, 1988).

The Hawthorn Group is composed of the Peace 

River Formation and the Arcadia Formation (fig. 2). 

As defined by Missimer (1999), the Peace River 

Formation contains an informal upper and lower 

member. These are referred to herein as the upper 

Peace River Formation and the lower Peace River Formation, respectively (fig. 2). The upper Peace River 

Formation is primarily composed of siliciclastic strata. 

The lower Peace River Formation is similar to the 

underlying Arcadia Formation; both are composed of 

limestone as well as dolosilt, sand, and clay. 

The Upper Floridan aquifer is composed of 

permeable portions of the lower Arcadia Formation, 

the Suwannee Limestone, the Ocala Limestone, and 

the Avon Park Formation. None of the test coreholes 

drilled for this study penetrate rocks of the Upper 

Floridan aquifer; however, the seismic-reflection 

survey probably contains reflections from strata of 

the upper portion of the Upper Floridan aquifer.

GEOPHYSICAL CHARACTERIZATION OF 

GROUND-WATER SYSTEMS OF THE 

CALOOSAHATCHEE RIVER BASIN

 Seismic-reflection and GPR profiles, when 

combined with geologic and hydrologic data, can contribute substantially to the characterization of hydrogeologic properties of shallow aquifers and confining 

units. A marine seismic-reflection survey and several 

GPR surveys were used to characterize the hydrogeologic framework of the ground-water systems of the 

Caloosahatchee River Basin. Seven test coreholes 

were drilled to link subsurface hydrogeologic features 

to the geophysical profiles. Age constraints determined 

by micropaleontologic and strontium-isotope data 

were used to correlate reflections on seismic profiles 

with lithologic units in cores. Interpretations of some 

depositional environments were strengthened by 

including micropaleontologic data.

Marine Seismic-Reflection Survey

The seismic-reflection survey spanned the 

Caloosahatchee River and part of San Carlos Bay 

(Locker and Hine, 1999). The primary survey area 

extends more than 38.5 mi from Moore Haven Lock 

(S-77) to the Franklin Lock (S-79) as shown in figure 

1. An additional seismic profile from Franklin Lock to 

San Carlos Bay (fig. 1) was made, in part, for comparison with previous seismic profiles made in San Carlos 

Bay by Missimer and Gardner (1976) and Scholz and 

Cunningham (1997). 

The seismic survey from Moore Haven to San 

Carlos Bay has been divided into five seismic-reflection 

survey segments as shown in figure 1. The division is 

based on similarity of seismic-reflection configurations and continuity along discrete lengths of the survey. An interpretive line drawing of survey segments 1 

to 3 and the eastern part of segment 4, between Moore 

Haven and Franklin Lock, is shown in figure 3.

Survey Segment 1 

Survey segment 1 contains imaging of the 

Tamiami Formation, Peace River Formation, Arcadia 

Formation, surficial aquifer system, and intermediate 

confining unit (fig. 4). Seismic reflections within the 

Tamiami Formation are discontinuous with parallel, 

subparallel, and wavy parallel configurations (fig. 4). 

Seismic reflections assigned to the Tamiami Formation 

drape over the paleotopography of a truncation surface 

at the top of the upper Peace River Formation (fig. 4). 

Missimer (1999) reported a 0.2-Ma hiatus at this discontinuity between the Tamiami Formation and upper 

Peace River Formation in southwestern Florida.

The presence of the silicoflagellates Dictyocha 

ornata africana, D. ornata ornata, and D. ornata 

tamarae from mudstones in the middle part of the 

Tamiami Formation in test corehole GL-329 and the 

lower Tamiami Formation in test corehole GL-327 

indicates assignment of these reflections to the late 

Pliocene (table 2 and fig. 5). The late Pliocene age for 
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 9

the lower Tamiami Formation is corroborated 

by two ages (2.15 and 1.91 Ma) derived from 

strontium isotopes (table 3). Coccoliths from 

the base of the Tamiami Formation in test 

corehole GL-329 suggest probable correlation 

of basal Tamiami reflections to Subzone 

CN12aA or to the late-early Pliocene based on 

the presence of rare Discoaster surculus and 

Sphenolithus sp. but without Reticulofenestra 

pseudoumbilca (table 4 and figs. 5 and 6).

Correlation of the survey segment 1 

seismic-reflection profile to the GL-326 and 

GL-329 test coreholes suggests that sediments 

of the Tamiami Formation probably crop out 

along the river bottom (about 45 ft below land 

surface) at these test corehole locations. Sand 

and shells of moderate to high hydraulic conductivity that overlie clay (at 37 ft below land 

surface) of very low hydraulic conductivity 

are included in the Tamiami Formation at the 

GL-326 test corehole (see appendix). Sand of 

moderate hydraulic conductivity is included in 

the upper Tamiami at the GL-329 test corehole 

(see appendix). These coreholes suggest that 

both the water-table aquifer and the Tamiami 

confining zone (fig. 2) of Smith and Adams 

(1988) may crop out along the Caloosahatchee 

River bottom in the western part of the survey 

segment, and perhaps elsewhere. 

In the western part of survey segment 1, 

seismic reflections assigned to the upper Peace 

River Formation are discontinuous, oblique, 

and progradational. These reflections are truncated updip by a prominent seismic-sequence 

boundary (fig. 4). The progradational seismicreflection patterns of the upper Peace River 

Formation likely represent the eastern flank of 

a deltaic depositional system. The patterns are 

similar to prograding deltaic clinoforms identified in the Fort Myers area by previous 

investigators (Missimer and Gardner, 1976; 

Evans and Hine, 1991; Scholz and Cunningham, 1997). Closer to Moore Haven, the 

reflections within the upper Peace River Formation more closely approach a horizontal and 

wavy configuration (fig. 4, easternmost area), 

but are widely interrupted by areas of chaotic 

reflections that cannot be reliably interpreted.

Figure 8

? ?

Figure 4 Figure 7

Figure 9

? ?

?

?

? ?

Arcadia Formation

Upper Peace

River Formation 50

100150200250300350

0

L-5809

S-78

Ortona Lock La Belle

S-77

Moore Haven S-79 Franklin Lock

AY TRAVELTIME, TWO-W

IN MILLISECONDS

DEPTH, IN FEET

Top carbonate zoneof sandstone aquifer

River bottom

Segment 4 Segment 3 Segment 2 Segment 1

Paleotopographic High

Downlapunconformity

?

Lower PeaceRiver Formation

? ?

Lower Peace

River Formation

River Formation Upper Peace

Arcadia Formation ?

GL-323 GL-325

Upper Peace

River Formation

0 5 10 MILES0 5 10 KILOMETERS

APPROXIMATE HORIZONTAL SCALE

GL-329 GL-326 GL-327

Tamiami Formation

01002003004005006007008009001,0001,100

EXPLANATION

Tamiami FormationUpper Peace River FormationLower Peace River FormationArcadia Formation

Figure 3. Interpretive line drawing based on marine seismic-reflection profiles along the Caloosahatchee River from structures S-77 to S-79. Oblique and sigmoidal 

progradational reflections indicate the presence of a regional-scale deltaic depositional system within the upper Peace River Formation approximately between La Belle and test corehole GL-326.
10 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

Figure 4. Seismic-reflection profile between Ortona Lock and Moore Haven (location in fig. 3). The thick section of oblique, progradationassigned to the upper Peace River Formation (UPR), and the overlying subhorizontal reflections are assigned to the Tamiami Formationlower Peace River Formation.

West R

? ? 

Arcadia Formation?

Eastwardprogradingclinoforms

Tamiami Formation

Unconformity/

Upper Peace

River Formation

5,000 5,500 6,000 6,500 

0

50

100150200250

20

100

406080

120140160180200220240260280300320340360380

0

600400450500550650700750800

DEPTH, IN FEET

USING 5,578 FEET

PER SECOND

DEPTH, IN FEET

USING 7,218 FEET

PER SECOND

?

TWO-WAY TRAVELTIME, IN MILLISECONDS 350

0

5

0.5 

0 1 K

Shot point

GL-329

Undifferentiated

Fill

Tamiami Formation

GL-326

Fill and undifferentiated

Caloosahatchee and Tamiami Formations

UPR LPR
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 11

Table 2. Occurrence of stratigraphically important silicoflagellate taxa in test coreholes GL-327 and GL-329

[UPR, upper Peace River Formation; LPR, lower Peace River Formation; +, present; -, not present; --, not determined]

Sample

depth

(feet)1

Silicoflagellates 

(barren or

 present)

Stratigraphic

 unit

Subepoch2

Silicoflagellate taxa3

Dictyocha

ornata 

africanus

Dictyocha

ornata ornata

Dictyocha 

ornata tamarae

GL-327

102.5 Present Tamiami Late Pliocene ++ +

108.0 Present Tamiami Late Pliocene + + +

109.7 Present Tamiami Late Pliocene ++ +

113.4 Present Tamiami Late Pliocene + + +

116.1 Present Tamiami Late Pliocene ++ +

120.0 Present Tamiami Late Pliocene + + +

121.2 Present Tamiami Late Pliocene ++ +

124.9 Present Tamiami Late Pliocene + + +

130.4 Barren Tamiami -- -- -

208.5 Barren UPR -- - - -

251.5 Barren UPR -- -- -

302.6 Barren UPR -- - - -

319.0 Barren UPR -- -- -

326.9 Barren UPR -- - - -

337.5 Barren UPR -- -- -

352.5 Barren UPR -- - - -

361.2 Barren UPR -- -- -

371.5 Barren UPR -- - - -

383.1 Barren UPR -- -- -

429.0 Barren UPR -- - - -

445.2 Barren UPR -- -- -

449.2 Barren LPR? -- - - -

453.1 Barren LPR? -- -- -
12 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

GL-329

 72.9 Present Tamiami Late Pliocene ++ -

 74.5 Present Tamiami Late Pliocene + - -

 76.7 Present Tamiami Late Pliocene +- +

 77.9 Present Tamiami Late Pliocene + - -

226.0 Barren UPR -- -- -

243.1 Barren UPR -- - - -

270.0 Barren UPR -- -- -

282.8 Barren UPR -- - - -

311.8 Barren UPR -- -- -

312.1 Barren UPR -- - - -

334.5 Barren UPR -- -- -

335.5 Barren UPR -- - - -

344.5 Barren UPR -- -- -

366.5 Barren UPR -- - - -

367.5 Barren UPR -- -- -

382.0 Barren UPR -- - - -

398.0 Barren LPR? -- -- -

398.3 Barren LPR? -- - - -

411.0 Barren LPR? -- -- -

417.5 Barren LPR? -- - - -

1Below ground surface.

2Subepoch names reported in accordance with integrated magnetobiochronologic time scale of Berggren and others (1995).

3Identification by David Bukry, U.S. Geological Survey, Menlo Park, Calif.

Table 2. Occurrence of stratigraphically important silicoflagellate taxa in test coreholes GL-327 and GL-329 (Continued)

[UPR, upper Peace River Formation; LPR, lower Peace River Formation; +, present; -, not present; --, not determined]

Sample

depth

(feet)1

Silicoflagellates 

(barren or

 present)

Stratigraphic

 unit

Subepoch2

Silicoflagellate taxa3

Dictyocha

ornata 

africanus

Dictyocha

ornata ornata

Dictyocha 

ornata tamarae
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 13 Figure 5. Hydrogeologic section A-A′ showing test coreholes drilled for this study near the Caloosahatchee River. Site locations s

Some gamma-ray logs used to correlate between wells are shown.

0 200 400

GAMMA RAY

(COUNTS PER SECOND)

600

0 200 400

GAMMA RAY

(COUNTS PER SECOND)

0 300

GAMMA RAY

(COUNTS PER SECOND)

FILLQUARTZ SANDSHELLY QUARTZ SANDPHOSPHATE SANDDIATOMACEOUS MUDSTONETERRIGENOUS MUDSTONEMARLPELECYPOD SHELLSDOLOSILTDOLOSTONELIMESTONE

EXPLANATION

TD 100 feet

UPPER

PEACE RIVER

FORMATION

LOWER

PEACE RIVER

FORMATION

LOWER

PEACE RIVER

FORMATION(?)

TAMIAMI

FORMATION

BUCKINGHAM LIMESTONE

MEMBER OF

TAMIAMI FORMATION

CLASTIC ZONE OF

SANDSTONE AQUIFER

CLASTIC ZONE OF

CARBONATE ZONE OF

SANDSTONE AQUIFER

CARBONATE ZONE OF

SEMICONFINING TO

CONFINING

SEM

SEMICONFINING TO

CONFINING

SEMICONFINING TO

CONFINING

WATER-TABLE

AQUIFER

WATER-TABLE

AQUIFER

SAND

AQUIFER

(UNNAMED)

SEMICONFINING TO

CONFINING

UNDIFFERENTIATED

LAKE FLIRT

MARL

UNDIFFERENTIATED

UNDIFFERENTIATED

ARCADIA

FORMATION ARCADIA

FORMATION

“LOWER

HAWTHORN”(?)

TD 200.5 feet

TD 401 feet

TD 2,500 feet

TD 401 feet

TD 39.5

feet

USGS

L-5809

USGS

GL-325

USGS

GL-323

USGS

GL-32

USGS

GL-329

ALTITUDE, IN FEET

West

A 

Sea level

-100

-50

50

UndifferentiatedLimestone

-150

-200-250

-300

-350

-400

-450

UPPER

PEACE RIVER

FORMATION

UPPER

PEACE RIVER

FORMATION

CN8

19.02Ma

22.33Ma

23.21Ma23.77Ma

24.13Ma

10.37Ma

SFWMD

W-17591

0 200 400

GAMMA RAY (COUNTS PER SECOND)

+++

+

+

++

+

+

+

+ ++++

+

+

CN10b or higher

ProbableCN12aA

LatePliocene

CN10-CN11

Cn10

L MioPlio FO 5.5 Ma T. oestrupii

CN10-CN11

Late Miocene

to Pliocene

+

HYDROSTRATIGRAPHICBOUNDARY (APPROXIMATE)

NO CORE RECOVERED

Ma MILLION YEARS

NANNOFOSSIL ZONEU. S. GEOLOGICAL SURVEYSOUTH FLORIDA WATERMANAGEMENT DISTRICT

SFWMD

USGS

MICROPALEONTOLOGY SAMPLESTRONTIUM-ISOTOPE SAMPLELITHOSTRATIGRAPHIC BOUNDARY(APPROXIMATE WHERE DASHED)

TD

FO

TOTAL DEPTH, IN FEETBELOW LAND SURFACEFIRST OCCURRENCE

VERTICAL SCALE GREATLY EXAGGERATED

0 5 MILES

0 4 KILOMETERS

+

+

11.37Ma

11.17Ma

12.81Ma

18.38 Ma (probably reworked Arcadia material)19.02 Ma (probably reworked Arcadia material)

19.10 Ma (probably reworked material)

+

+

+++

Unconformity
14 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

The lower terminations of the clinoforms 

assigned to the upper Peace River Formation are 

masked by chaotic seismic reflections (fig. 4) possibly 

created by anomalous energy reflected off steeply 

inclined areas of the river bottom. Presumably the 

lower clinoforms downlap onto subhorizontal, slightly 

wavy, parallel seismic reflections assigned to the 

lower Peace River Formation below the zone of chaotic 

reflections (fig. 4). The subhorizontal reflections of 

the lower Peace River Formation are interpreted to 

grade downward into reflections with a similar reflection configuration assigned to the Arcadia Formation 

and possibly the upper part of the Suwannee 

Limestone (fig. 4).

Survey Segment 2

 Survey segment 2 includes seismic representation of the same formations and aquifers as shown in 

survey segment 1. Seismic reflections assigned to the 

Tamiami Formation are represented by only a thin zone 

of poorly defined reflections beneath the river bottom 

in an area near test corehole GL-323 (fig. 7). These 

seismic reflections are within a zone of poor data 

quality, and their geometry is obscured by waterbottom reflections. Quartz sands of the Tamiami 

Formation crop out at the floor of the Caloosahatchee 

River at the GL-323 location, based on correlation of 

the GL-323 test corehole data to survey segment 2 

(fig. 7). Visual estimates of the hydraulic conductivity 

Table 3. Strontium-isotope data and ages from shell material collected 

from test coreholes GL-323, GL-325, GL-327, and L-5809

[All shell material collected has low-magnesium calcite mineralogy determined from 

x-ray diffractometer records. Ma, million years]

Local well

identifier

Depth

(feet)1

Stratigraphic

 position

87Sr/86Sr2 Estimated 

age (Ma)3

GL-323

217.6 Upper Peace River 0.708518 19.024

218.0 Upper Peace River .708564 18.384

255.5 Arcadia .708518 19.02

265.2 Arcadia .708333 22.33

279.2 Arcadia .708299 23.21

322.0 Arcadia .708270 23.77

364.6 Arcadia .708249 24.13

GL-325

147.6 Lower Peace River .708879 10.37

162.7 Lower Peace River .708849 11.37

172.8 Lower Peace River .708855 11.17

183.5 Lower Peace River .708821 12.81

GL-327

67.2 Tamiami .709081 2.15

94.3 Tamiami .709088 1.91

L-5809 37.5 Tamiami .708513 19.104

1Below ground level.

2Measured at the University of Florida Thermal Ionization Mass Spectrometry 

Laboratory, normalized to 86Sr/88Sr = 0.1194, and corrected to a mean value of SRM-987 = 

0.710249 (+0.000023). A value of 1 x 10-6 was subtracted from all 87Sr/86Sr values to correct 

for an interlaboratory bias between the University of Florida values and data presented in the 

“Look-up Table Version 3:10/99” of Howarth and McArthur (1997).

3Ages derived from “Look-Up Table Version 3:10/99” of Howarth and McArthur 

(1997), and used in accordance with time scale of Berggren and others (1995).

4Probable reworked material from Arcadia Formation.
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 15

Table 4. Occurrence of stratigraphically important coccolith taxa in test coreholes GL-323, 

GL-325, GL-327, and GL-329 

[Identification of coccoliths by David Bukry, U.S. Geological Survey, Menlo Park, Calif. UPR, upper 

Peace River Formation; LPR, lower Peace River Formation; --, not determined]

Well

identification

Sample depth1

(feet)

Stratigraphic

position

Coccoliths

 barren or

 present

Nannofossil zone2

GL-323

 109.2 UPR Barren --

 115.9 UPR Present CN10c-11

 134.2 UPR Barren --

 140.5 UPR Barren --

 153.8 UPR Present CN10-11

 223.4 UPR Present CN10c-11

 230.5 LPR Barren --

 292.7 Arcadia Barren --

GL-325

 121.0 UPR Present Miocene to Pliocene

 130.0 LPR Barren --

 192.7 LPR Present CN8

GL-327

100.2 Tamiami Barren --

102.5 Tamiami Barren --

108.0 Tamiami Barren --

109.7 Tamiami Barren --

113.4 Tamiami Barren --

116.1 Tamiami Barren --

120.0 Tamiami Barren --

121.2 Tamiami Barren --

124.9 Tamiami Barren --

126.3 Tamiami Barren --

130.4 Tamiami Barren --

208.5 UPR Barren --

251.5 UPR Barren --

302.6 UPR Barren --

319.0 UPR Barren --

326.9 UPR Barren --

337.5 UPR Barren --

352.5 UPR Barren --

361.2 UPR Barren --

371.5 UPR Barren --

383.1 UPR Barren --
16 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

GL-327

429.0 UPR Barren --

445.2 UPR Barren --

449.2 LPR? Barren --

453.1 LPR? Barren --

GL-329

 72.9 Tamiami Barren --

 74.5 Tamiami Barren --

 76.7 Tamiami Barren --

 77.9 Tamiami Barren --

153.2 Tamiami Present Probable CN12aA

226.0 UPR Barren --

243.1 UPR Barren --

270.0 UPR Barren --

282.8 UPR Barren --

311.8 UPR Barren --

312.1 UPR Barren --

334.5 UPR Barren --

335.5 UPR Barren --

344.5 UPR Barren --

366.5 UPR Barren --

367.5 UPR Barren --

382.0 UPR Barren --

398.0 LPR Barren --

398.3 LPR Barren --

411.0 LPR Barren --

417.0 LPR Barren --

1Depth reported below ground level.

2Coccolith floras assigned to the biostratigraphic zones of Okada and Bukry (1980) and reported in 

accordance with integrated magnetobiochronologic time scale of Berggren and others (1995).

Table 4. Occurrence of stratigraphically important coccolith taxa in test coreholes GL-323, 

GL-325, GL-327, and GL-329 (Continued)

[Identification of coccoliths by David Bukry, U.S. Geological Survey, Menlo Park, Calif. UPR, upper 

Peace River Formation; LPR, lower Peace River Formation; --, not determined]

Well

identification

Sample depth1

(feet)

Stratigraphic

position

Coccoliths

 barren or

 present

Nannofossil zone2
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 17

E. huxleyi (0.248)

P. lacunosa (0.408)

G. parallela (0.94)

H. sellii (1.41)

C. macintyrei (1.65)

G. caribbeanica (1.7)

D. brouweri (1.95)

D. pentaradiatus (2.36)

D. surculus (2.51)

D. tamalis (2.82)

D. variablis (3.11)

Sphenolithus spp. (3.62)

R. pseudoumbilica (3.83)

Amaurolithus spp. (4.50)

C. acutus (5.04)

C. rugosus (5.05)

T. rugosus (5.23) C. acutus (5.09)

Thalassiosira

pareoestrupii (6.0)

D. quinqueramus (5.6)

A. amplificus (6.6)

Thalassiosira

oestrupii (5.5)

A. amplificus (5.9)

Paracme (6.8) R. pseudoumbilica

Paracme (8.8) R. pseudoumbilica

A. primus (7.2)

D. loeblichii (7.4)

M. convalis (7.8)

D. berggrenii (8.6)

D. loeblichii (8.7)

D. bollii (9.1)

D. hamatus (9.4)

C. calyculus (9.36)

M. convalis (9.5)

D. neohamatus (9.6)

D. hamatus (10.7)

Nannofossil datums

(million years)

Diatom

datums

(million

years)

First occurrence surface

Last occurrence surface

11

CN14

CN13

CN12

CN8

CN10

CN9

2

CN7

CN6

CN11

2A

3

3A

4

1

Miocene

5

3B

Pleistocene

4A

Pliocene

Gelasian

Time

(million years)

Polarity

Age

Epoch

Series

Zones of Okada

and Bukry (1980);

Bukry (1991) a

b

a

c

d

b

b

c

b

b

a

b

a

aA

aB

aC

a

CN15

Late

Middle

Late

Late

Early

Early

Tortonian Calabrian Piacenzian Zanclean Messinian

Chrons

0

Figure 6. Correlation of the chronostratigraphy of part of the late Tertiary geomagnetic polarity time scale (Berggren and others, 1995). Coccolith zonation from 

Ocean Drilling Project Leg 171B at the Blake Nose east of the Florida Peninsula (Shipboard Scientific Party, 1998) with normalized additions of subzones CN12aA, aB, and aC from Bukry (1991) and diatom datums from offshore California.
18 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

0

50

100150200250

GL-323

RIVER

SW BEND ESE

Upper Peace

River Formation

Westward prograding

clinoforms

TWO-WAY TRAVELTIME, IN MILLISECONDS

River bottom

DEPTH, IN FEET

USING 5,315 FEET

PER SECOND

DEPTH, IN FEET

USING 8,203 FEET

PER SECOND

Shot point 4,300 4,000 3,500 3,000 2,500 2,000 1,500 

Arcadia Formation

UndifferentiatedLake Flirt Marl

Lower

Peace River

Formation

Arcadia

Formation

300350400450500600550650700750

800

20

100

406080

120140160180200220240260

0

Tamiami Formation

5 1 KILOMETER

0.5

00 1 MILE

Erosional

unconformity/

seismic sequence

boundary

A UPR LPR

Figure 7. Seismic-reflection profile between La Belle and Ortona Lock showing strata drilled at the GL-323 test corehole (location in figprogradational reflections, identified as siliciclastics and assigned to the upper Peace River Formation (UPR), downlap onto a major seisdisplays local erosional truncation. Parallel reflections below the seismic sequence boundary are assigned to the lower Peace River FoFormation (A). At the GL-323 test corehole, the unnamed sand of the Tamiami Formation may be exposed by dredging at the floor of th
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 19

of the quartz sand of the Tamiami Formation in the 

GL-323 test corehole suggest that sand of low to moderate hydraulic conductivity (see appendix) crop out at 

the bottom of the Caloosahatchee River at this location, 

possibly providing the potential for direct exchange 

between the river and aquifer.

Throughout most of the western half of survey 

segment 2, seismic reflections assigned to the upper 

Peace River Formation have either a sigmoid or oblique 

progradational configuration (figs. 7 and 8). Where 

visible, the upper parts of the oblique progradational 

reflections are terminated by an irregular, subhorizontal reflection representing the dredged floor of 

the Caloosahatchee River (fig. 8, shot points 

1,000-2,000) and probably crop out at the river floor in 

the Ortona area between the western side of Lake 

Hicpochee and La Belle (fig. 1). Micropaleontologic 

results support the assignment of the progradational 

reflections to the upper Peace River Formation (tables 

4 and 5). Samples from the GL-323 and GL-325 test 

coreholes suggest an early Pliocene age for these progradational strata based on diatom taxonomy (table 5 

and fig. 6) and assignment to Zones CN10c to CN11 

(fig. 6) based on coccolith taxonomy (table 4). The progradational seismic-reflection patterns of the upper 

Peace River Formation likely represent the western 

flank of a deltaic depositional system that is similar to 

prograding deltaic clinoforms identified in the Fort 

Myers area by previous investigators (Missimer and 

Gardner, 1976; Evans and Hine, 1991; Scholz and Cunningham, 1997). This environmental interpretation is 

consistent with ecological data for benthic-foraminiferal genera identifications for samples from test coreholes GL-323 and GL-325 (tables 6 and 7) that suggest 

deposition in a shallow-marine shelf environment. The 

depositional axis of the deltaic depositional system is 

shown in figure 3.

The upper Peace River Formation crops out 

along the floor of the Caloosahatchee River at test 

corehole GL-325, based on correlation of test corehole 

GL-323 to survey segment 2 (fig. 8). Visual estimates 

of the hydraulic conductivity of the upper Peace River 

Formation in test corehole GL-325 suggest that quartz 

sand of moderate hydraulic conductivity (see appendix) crops out at the bottom of the Caloosahatchee 

River at this location, and thus, the potential exists for 

direct exchange between the water-table aquifer and 

the river.

A major seismic-sequence boundary separates the 

upper Peace River Formation from the lower Peace River 

Formation (fig. 7). This seismic-sequence boundary 

approaches to within tens of feet of the river bottom at 

La Belle, which contrasts with its approximate 350 ft 

depth between Ortona Lock and Moore Haven (fig. 3). 

Westward dipping, progradational reflections of the upper 

Peace River Formation downlap onto much of this unconformity. The erosion of strata beneath the unconformity is 

represented by local termination of underlying reflections 

(figs. 7 and 8). This boundary is also indicated by a major 

shift in lithofacies and a sharp increase in gamma-ray 

activity in test coreholes GL-323 and GL-325 (fig. 5). 

In these coreholes, quartz sand or quartz conglomerate 

containing pebble-sized phosphorite grains of the upper 

Peace River Formation overlie dolosilt of the lower Peace 

River Formation (fig. 5 and appendix). 

The seismic reflections assigned to the lower 

Peace River Formation have a subhorizontal, parallel 

configuration that has a broad, wavy configuration pattern (figs. 7 and 8). Coccoliths from a depth of 192.7 ft 

in the GL-325 test corehole (fig. 5 and table 5) indicate 

assignment to Zone CN8 or early-late Miocene (fig. 6). 

Data derived from strontium isotopes suggest an age 

between 12.81 and 10.37 Ma for the lower Peace River 

Formation in test corehole GL-325 (table 3 and fig. 5). 

Both coccolith and strontium isotope ages indicate these 

parallel reflections are equivalent to the lower Peace 

River Formation of Missimer (1999), which ranges in 

age from 11 to 8.5 Ma.

Concordant seismic reflections delineate the 

boundary between the lower Peace River Formation and 

underlying Arcadia Formation (figs. 7 and 8). The 

formation contact between the Peace River Formation 

and the Arcadia Formation is an abrupt contact and possible erosional discontinuity in test corehole GL-323 (see 

appendix). This contact has been defined as a major 

depositional sequence boundary by Missimer (1997) and 

Guertin and others (2000) in southwestern Florida. Data 

derived from strontium isotopes suggest an age between 

24.13 to 19.02 Ma for the Arcadia Formation in test 

corehole GL-323 (table 3 and fig. 5).

Survey Segment 3

 Survey segment 3 contains seismic images of the 

Peace River Formation, possibly the Arcadia Formation, 

the surficial aquifer system, and intermediate confining 

unit (figs. 1-3). Seismic-reflection profiles indicate that 

the base of the upper Peace River Formation is shallower 

in this segment than in others (fig. 3).
20 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla. Figure 8. Seismic-reflection profile between La Belle and the GL-323 test corehole (location in fig. 3). The section of oblique prograding 

the upper Peace River Formation (UPR) downlaps onto a major seismic sequence boundary that displays local erosional truncation. Thbelow the unconformity are assigned to the lower Peace River Formation (LPR) based on drilling results. Near the GL-325 test corehole, upper Peace River Formation probably crop out at the river bottom. Parallel reflections of the lower Peace River Formation are underlaiof the Arcadia Formation (A). 

0

50

100150

GL-325 SW

River bottom

W

Upper Peace

River Formation

Gray panels mask

poor data areas

Erosional

unconformity

Shaded ar

that is possi

Fill

?

?

?

?

Lower Peace

River Formation

Arcadia

Formation

Arcadia

Formation

?

20

80

260

0

100 Shot point 500 1,000 1,500 2,000 2,500 3,000 3,500 

TWO-WAY TRAVELTIME, IN MILLISECONDS

100120140160180200220240

4060

UPR LPR

5 1 KILOMETER

0.5

00 1 MILE

Note for depth scale at GL-325 (Vp represents compressional 44-130 feet uses Vp= 5,315 feet per second130-270 feet uses Vp= 8,203 feet per second

Lake Flirt Marl

Undifferentiated Fort Thompson and Caloosahatchee Formations 
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 21

Table 5. Occurrence of stratigraphically important diatom taxa in test coreholes GL-323, GL-325, GL-327, and GL-329

[Diatom identification by J.A. Barron, U.S. Geological Survey, Menlo Park, Calif. UPR, upper Peace River Formation; LPR, lower Peace River 

Formation; Ma, million years; <, less than the value; --, not determined; ?, unknown]

Well

identification

Sample depth1

 (feet)

Diatoms

 barren or

 present

Stratigraphic

unit Subepoch2 Estimatedage2 (Ma) Taxa present

GL-323

 109.2 Present UPR Early Pliocene <5.5

Hemidiscus ovalis, 

Koizumia tatsunokuchiensis, 

Thalassiosira eccentrica, 

T. leptopus, 

T. oestrupii

 140.5 Present UPR Early Pliocene <5.5

Hemidiscus ovalis, 

Thalassiosira eccentrica, 

T. oestrupii

 223.4 Barren UPR -- -- --

 230.5 Barren LPR -- -- --

 292.7 Barren Arcadia -- -- --

 373 Barren Arcadia -- -- --

GL-325

 121 Present UPR

Late Miocene to 

early Pliocene

<6.0

Azpeitia vetustissimus, 

Koizumia adaroi, 

Koizumia tasunokuchiensis, 

Thalassiosira eccentrica, 

T. leptopus, 

T. Praeoestrupii

 130 Barren LPR -- -- --

 192.7 Barren LPR -- -- --

GL-327

102.5 Present Tamiami Late Miocene to 

Holocene

<11.2 Hyalodiscus spp. 

Paralia sulcata

108.0 Present Tamiami Pliocene <5.5 Hemidiscus ovalis,

Nitzshcia granulata

120.0 Present Tamiami ? ?

Actinocyclus divisus

Actinocyclus octonarius

Actinoptychus sp.

Azpeitia nodulifer

Hyalodiscus sp.

Navicula sp.

Paralia sulcata

Thalassiosira eccentrica

130.4 Barren Tamiami -- -- --

208.5 Barren UPR -- -- --

251.5 Barren UPR -- -- --

302.6 Barren UPR -- -- --

319.0 Barren UPR -- -- --

326.9 Barren UPR -- -- --

337.5 Barren UPR -- -- --

352.5 Barren UPR -- -- --

361.2 Barren UPR -- -- --

371.5 Barren UPR -- -- --
22 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

GL-327

383.1 Barren UPR -- -- --

429.0 Barren UPR -- -- --

445.2 Barren UPR -- -- --

449.2 Barren LPR? -- -- --

453.1 Barren LPR? -- -- --

GL-329

226.0 Barren UPR -- -- --

243.1 Barren UPR -- -- --

270.0 Barren UPR -- -- --

282.8 Barren UPR -- -- --

311.8 Barren UPR -- -- --

312.1 Barren UPR -- -- --

334.5 Barren UPR -- -- --

335.5 Barren UPR -- -- --

344.5 Barren UPR -- -- --

366.5 Barren UPR -- -- --

367.5 Barren UPR -- -- --

1Depth reported below ground level.

2Diatom floras dated using the correlations of Barron (1992) and reported in accordance with integrated magnetobiochronologic time 

scale of Berggren and others (1995). 

Table 5. Occurrence of stratigraphically important diatom taxa in test coreholes GL-323, GL-325, GL-327, and GL-329 

(Continued)

[Diatom identification by J.A. Barron, U.S. Geological Survey, Menlo Park, Calif. UPR, upper Peace River Formation; LPR, lower Peace River 

Well

identification

Sample depth1

 (feet)

Diatoms

 barren or

 present

Stratigraphic

unit Subepoch2 Estimatedage2 (Ma) Taxa present

Seismic reflections throughout much of survey 

segment 3 cannot be reliably interpreted because they 

have a chaotic reflection configuration or are overprinted by multiples. Oblique progradational configurations present in the eastern part of survey segment 3 are 

assigned to the upper Peace River Formation. The 

uppermost reflections are terminated by an irregular, 

subhorizontal reflection representing the dredged floor 

of the Caloosahatchee River. The progradational 

seismic-reflection patterns of the upper Peace River 

Formation are the westward extension of the deltaic 

depositional system imaged in survey segments 1 and 2 

(figs. 4, 7, and 8). In the upper Peace River Formation, 

progradational seismic reflections downlap onto subhorizontal, parallel seismic reflections assigned to the 

lower Peace River Formation (fig. 3). The subhorizontal 

reflections of the lower Peace River Formation may 

grade downward into reflections with a similar reflection configuration assigned to the Arcadia Formation. 

Survey Segment 4

Survey segment 4 contains imaging of the 

Tamiami Formation, Peace River Formation, possibly the Arcadia Formation, the surficial aquifer system, and the intermediate aquifer system (figs. 1-3 

and 9). The continuity in seismic data is poorest 

along this section of the river, with short areas of 

reliable data broken intermittently by data of poor 

quality. Much of the seismic data in survey segment 

4 cannot be interpreted because of a chaotic reflection configuration or overprinting by multiples. 

To aid in visualizing survey segments of reliable 

seismic data, the portions of poor quality are not 

shown in figure 9. Lithostratigraphic results from 

test corehole L-5809 (fig. 9 and appendix) were 

used to assign groups of seismic reflections to 

established lithostratigraphic and hydrogeologic 

units (fig. 2). 
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 23

Table 6. Benthic foraminiferal genera listed alphabetically and their distribution with depth in test coreholes GL-323, GL-325, 

GL-327, GL-329, and L-5809

[References to Bock and others (1971), Poag (1981) and Jones (1994) assisted L.A. Guertin in identification of benthic foraminifers. 

B, Buckingham Limestone member of the Tamiami Formation; LPR, lower Peace River Formation; US, unnamed sand of the Tamiami 

Formation; UPR, upper Peace River Formation; --, not determined. Rare indicates less than 15 specimen per sample, common indicates 15 to 

45 specimen per sample, abundant indicates greater than 45 specimen per sample]

Well

identification

Sample

depth1

(feet)

Benthic

forams

 barren or

present

Stratigraphic

 position Genera present

GL-323

 45.0 Barren US --

 54.5 Barren UPR --

 59.0 Barren UPR --

 68.0 Barren UPR --

 76.1 Barren UPR --

 81.6 Barren UPR --

 89.1 Barren UPR --

 96.5 Barren UPR --

 100.4 Barren UPR --

 103.75 Barren UPR --

 114.3 Barren UPR --

 120.0 Barren UPR --

 127.0 Present UPR Common Bulimina, Buliminella, Cancris, Cibicides, Elphidium, Hanzawaia, and Nonion

 130.9 Present UPR Rare Buliminella and Elphidium.

 132.4 Present UPR Abundant Buliminella and Elphidium.

 135.5 Present UPR Common Buliminella and Elphidium.

 143.7 Present UPR Rare Buliminella, Elphidium and Hanzawaia.

 153.3 Present UPR Common Buliminella, Elphidium and Hanzawaia; rare Nonion and Rosalina.

 157.8 Present UPR Rare Buliminella and Elphidium.

 163.4 Present UPR Rare Buliminella, Elphidium and Hanzawaia.

 172.1 Present UPR Common Buliminella, Cancris, Cibicides, Discorbis, Elphidium, Hanzawaia, Nonion

and Rosalina.

 179.6 Present UPR Rare Buliminella, Elphidium, Hanzawaia, Nonion and Rosalina.

 185.3 Present UPR Rare Buliminella, Elphidium, Hanzawaia and Rosalina.

 199.8 Present UPR Rare Elphidium.

 203.4 Present UPR Common Elphidium; rare Buliminella, Discorbis and Planulina. 

 207.0 Present UPR Rare Elphidium.

 212.5 Present UPR Rare Elphidium.

 221.75 Present UPR Rare Elphidium.

 223.9 Barren UPR --

GL-325

 32.0 Barren UPR --

 42.5 Barren UPR --

 54.5 Barren UPR --

 65.0 Barren UPR --

 74.5 Barren UPR --

 83.2 Barren UPR --
24 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

GL-325

 93.0 Barren UPR --

 109.2 Barren UPR --

 121.0 Barren UPR --

 123.5 Present UPR Common Elphidium; rare Amphistegina, Buliminella, Cibicides, Fursenkonina, 

Hanzawaia, and Nonion. 

 126.2 Barren UPR --

 127.9 Barren UPR --

GL-327

 20.7 Barren Undifferentiated --

 28.7 Barren Undifferentiated --

 38.5 Barren Tamiami --

 66.7 Present Tamiami Rare Nonion, Quinqueloculina, and Triloculina

 84.7 Present Tamiami Rare Quinqueloculina, and Triloculina

 100.2 Present Tamiami Rare Ammonia, Homotrema, and Nonion

 102.5 Present Tamiami Rare Ammonia and Homotrema

 108.0 Barren Tamiami --

 109.7 Present Tamiami Rare Ammonia, Homotrema, and Nonion

 113.4 Present Tamiami Rare Ammonia

 116.1 Barren Tamiami --

 120.0 Barren Tamiami --

 121.2 Barren Tamiami --

 124.9 Barren Tamiami --

 126.3 Present Tamiami --

 130.4 Barren Tamiami Rare Nonion

 156.5 Barren UPR --

 178.7 Barren UPR --

 208.5 Barren UPR --

 223.7 Barren UPR --

 251.5 Barren UPR --

 255.6 Barren UPR --

 278.0 Barren UPR --

 302.6 Barren UPR --

 319.0 Barren UPR --

 326.9 Barren UPR --

 337.2 Barren UPR --

 352.5 Barren UPR --

Table 6. Benthic foraminiferal genera listed alphabetically and their distribution with depth in test coreholes GL-323, GL-325, 

GL-327, GL-329, and L-5809 (Continued)

[References to Bock and others (1971), Poag (1981) and Jones (1994) assisted L.A. Guertin in identification of benthic foraminifers. 

B, Buckingham Limestone member of the Tamiami Formation; LPR, lower Peace River Formation; US, unnamed sand of the Tamiami 

Formation; UPR, upper Peace River Formation; --, not determined. Rare indicates less than 15 specimen per sample, common indicates 15 to 

45 specimen per sample, abundant indicates greater than 45 specimen per sample]

Well

identification

Sample

depth1

(feet)

Benthic

forams

 barren or

present

Stratigraphic

 position Genera present
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 25

 361.2 Barren UPR --

 371.5 Barren UPR --

 383.1 Barren UPR --

GL-327 429.0 Barren UPR --

 445.8 Barren UPR --

 449.2 Barren LPR? --

 453.1 Barren LPR? --

GL-329

 69.9 Present Tamiami Rare Nonion, Spirolina, Spiroloculina, and Triloculina

 71.8 Present Tamiami Rare Quinqueloculina

 77.8 Present Tamiami Rare Ammonia, Nonion, and Quinqueloculina

 153.2 Present Tamiami Rare Ammonia, Cancris, Hanzawaia and Nonion

L-5809

 5.8 ? B --

 9.1 Present B Rare Cibicides and Elphidium

 14.9 Present B Common Ammonia and Rosalina

 20.3 Present B Abundant Ammonia; common Cibicidoides, Elphidium, and Rosalina

 23.8 Present B Abundant Cibicidoides and Elphidium; common Buliminella, Cancris, Fursenkoinam, 

and Nonion

 25.0 Present B Common Cibicidoides, Elphidium, Fursenkoina, and Nonion; rare Buliminella and Cancris

 28.3 Present B Common Cibicidoides and Elphidium; rare Buliminella and Cancris, 

 29.9 Present B Rare Cancris, Cibicides, Cibicidoides, Elphidium, Fursenkoina, and Rosalina

 33.9 Barren B --

 35.0 Present B Common Bigenerina, Buliminella, Cancris, Cibicidoides, Elphidium, Fursenkina, 

Nonion, and Rosalina

 36.3 Barren B --

 40.5 Barren UPR --

 47.4 Present2 UPR --

 55.1 Barren UPR --

 60.8 Barren UPR --

 67.7 Barren UPR --

 71.8 Barren UPR --

 74.1 Barren UPR --

 77.5 Barren UPR --

 79.1 Barren UPR --

 86.7 Barren UPR --

1Depth reported below ground level. 

2Present but no identification due to recrystallization.

Table 6. Benthic foraminiferal genera listed alphabetically and their distribution with depth in test coreholes GL-323, GL-325, 

GL-327, GL-329, and L-5809 (Continued)

[References to Bock and others (1971), Poag (1981) and Jones (1994) assisted L.A. Guertin in identification of benthic foraminifers. 

B, Buckingham Limestone member of the Tamiami Formation; LPR, lower Peace River Formation; US, unnamed sand of the Tamiami 

Formation; UPR, upper Peace River Formation; --, not determined. Rare indicates less than 15 specimen per sample, common indicates 15 to 

45 specimen per sample, abundant indicates greater than 45 specimen per sample]

Well

identification

Sample

depth1

(feet)

Benthic

forams

 barren or

present

Stratigraphic

 position Genera present
26 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

Seismic reflections assigned to the Buckingham 

Limestone Member of the Tamiami Formation (fig. 2) 

are represented by only a thin zone of poorly defined 

reflections beneath the river bottom in an area near test 

corehole L-5809 and beyond in structural lows (fig. 9). 

These seismic reflections are within a zone of poor data 

quality, and their geometry is obscured by reflections at 

the river bottom. Where structural lows are present 

along survey segment 4, the Buckingham Limestone 

Member possibly crops out at the river bottom based 

on correlation of the L-5809 test corehole to survey 

segment 4 images (fig. 9 and appendix). Visual estimates 

in test corehole L-5809 indicate that marl, terrigenous 

mudstone, quartz and phosphatic sand, and dolosilt of 

the Buckingham Limestone Member mostly have very 

low to low hydraulic conductivity (see appendix). This 

suggests confinement between the surface water of the 

Caloosahatchee River and the ground-water system at 

structural lows.

A structural template, probably related to karstic 

collapse of deeper limestone that could be contained in 

the Floridan aquifer system, is responsible for a wavy, 

Table 7. Ecological data for benthic foraminiferal genera identified in test coreholes GL-323, GL-325, 

GL-327, GL-329, and L-5809

[Depth and environment information according to Murray (1991). Depth values originally published in meters;

>, greater than the value]

Genus

Approximate

water depth

(feet)

Environment

Ammonia 0-160 Brackish and hypersaline lagoons, inner shelf

Amphistegina 0-430 Coral reefs, lagoons

Bigenerina Shelf

Bulimina Inner shelf to bathyal

Buliminella Mainly shelf, but also lagoons and upper bathyal

Cancris 160-490 Inner shelf

Cibicides 0->6,600 Lagoons to bathyal

Cibicidoides Shelf to bathyal

Discorbis 0-160 Shelf

Elphidium1 0-160 Brackish to hypersaline marshes, lagoons, inner shelf

Fursenkoina 0-3,900 Lagoons to upper bathyal

Hanzawaia Inner shelf

Homotrema Marine, inner shelf

Nonion 0-590 Shelf

Planulina Shelf, bathyal

Quinqueloculina Hypersaline lagoons, marine shelf

Rosalina 0-330 Lagoon, inner shelf

Spirolina 0-200 Lagoons and nearshore

Spiroloculina 0-130 Lagoons, inner shelf

Triloculina Mainly hypersaline lagoons or marine inner shelf

1Poag (1981) states that Elphidium is abundant and widespread in coastal lagoons, bays, and estuaries.
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 27 Figure 9. Seismic-reflection profile between La Belle and S-79 (Franklin Lock). Location shown in figure 3. Test corehole L-5809 was s

high amplitude reflection at about 35 milliseconds depth. This reflection is assigned to the top of the carbonate zone of the sandstone aqby reflections imaging siliciclastics of the upper Peace River Formation (UPR) and the clastic zone of the sandstone aquifer (fig. 2). Pomay be related to karstification of deeper limestone strata. LPR represents the lower Peace River Formation.

Shallow dip controlled

by deeper structure

L-5809

West

Gray panels mask

poor data gaps

Shaded area is anomalous energy

that is possibly canal wall reflections?

Arcadia

Formation

?

Lower

Peace River

Formation?

?

Top carbonate

zone of

sandstone

aquifer

Clastic zone of

sandstone aquifer

Buckingham Limestone Memberof Tamiami Formation

Collapse

structure?

Collapse

structure?

Shot point 2,600 3,000 3,500 4,000 4,500 5,000 5,500 6,000 

Undifferentiated

Upper

Peace River

Formation

? ?

? 

?

UPR

LPR

0

50

100150

TWO-WAY TRAVELTIME, IN MILLISECONDS

00 

20

100

406080

Depth in feet 0

using 5,315 feet

per second

Depth in feet

using 8,203 feet

per second

250

300

200

150
28 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

parallel configuration pattern of the seismic reflections 

assigned to the upper Peace River Formation (fig. 9). 

The lower bounding seismic reflections of the upper 

Peace River Formation are concordant with seismic 

reflections assigned to the lower Peace River Formation below (fig. 9). The upper Peace River Formation 

possibly crops out at the floor of the Caloosahatchee 

River along structurally high areas east of test corehole L-5809, based on correlation of the corehole to 

survey segment 4 (fig. 9 and appendix). Visual estimates of hydraulic conductivity for the upper Peace 

River Formation in test corehole L-5809 suggest that 

quartz sand of moderate hydraulic conductivity (see 

appendix) may crop out along the bottom of the 

Caloosahatchee River in structurally high areas. This 

would potentially allow direct water exchange between 

the river and the clastic zone of the sandstone aquifer. 

Thus, a potential connection exists between the intermediate aquifer system and the Caloosahatchee River 

at structural highs (fig. 9).

The seismic reflections assigned to the lower 

Peace River Formation, as was the case with the upper 

Peace River Formation, have a wavy, parallel configuration pattern (fig. 9) that is also controlled by local 

structural deformation. The uppermost seismic reflections of the lower Peace River Formation have a stronger 

or higher amplitude than the reflections of the upper 

Peace River Formation. This change in amplitude is 

associated with the density change (in the sandstone 

aquifer) of the clastic-zone quartz sand and carbonatezone limestone. The strong seismic reflections bounding the top of the carbonate zone of the sandstone 

aquifer can be traced for several miles in the seismic 

profile, indicating that the aquifer can be mapped, at 

least locally, with seismic-reflection methods. The 

parallel reflections of the lower Peace River Formation may grade downward into reflections with a 

similar reflection configuration assigned to the Arcadia 

Formation (fig. 9).

Survey Segment 5

Survey segment 5 contains imaging of the 

Tamiami, Peace River, and Arcadia Formations (figs. 1, 

2, and 10), and the surficial and intermediate aquifer 

systems. In the Fort Myers area, survey segment 5 

seismic reflections assigned to the upper Peace River 

Formation (Missimer and Gardner, 1976; Missimer, 

1999) have either a sigmoid or oblique progradational 

configuration or subhorizontal, parallel configuration 

(fig. 10). The progradational seismic-reflection patterns 

of the upper Peace River Formation likely represent a 

deltaic depositional system as suggested by Missimer 

and Gardner (1976) and Missimer (1999). East of the 

delta, where the seismic reflections are subhorizontal, 

they drape over a seismic discontinuity separating the 

upper and lower Peace River Formations as shown by 

Missimer and Gardner (1976) and Missimer (1999). 

The progradational reflections of the upper Peace 

River Formation downlap onto this discontinuity 

(fig. 10). Seismic reflections below the discontinuity 

have a parallel configuration. These reflections assigned 

to the lower Peace River Formation are subhorizontal 

and locally have a broad, wavy configuration. The 

subhorizontal reflections of the lower Peace River 

Formation grade downward into reflections with a 

configuration similar to those assigned to the Arcadia 

Formation. Missimer (1999) shows that discontinuity 

between reflections of the lower Peace River Formation and the Arcadia Formation includes erosional 

truncation of uppermost seismic reflections of the 

Arcadia Formation. The wavy configuration pattern of 

limestone of the Hawthorn Group shown in figure 10 

is probably related to karstic collapse of deeper limestone that could be contained in the Floridan aquifer 

system, similar to the structures observed in survey 

segment 4 (fig. 9).

Ground-Penetrating Radar

Interpretations of GPR profiles are presented for 

two rural sites in the coastal lowlands that include the 

Caloosahatchee River Basin. The Indian Mound site 

(fig. 1) is located at the abandoned Florida Rock Industries sand pit and adjacent Indian Mound Park in 

Glades County. Data were collected on barren, sandy 

terrain and gravel roads. The CRS06 monitoring well 

site (fig. 1) in Hendry County includes a GPR traverse 

that runs parallel to the C-3 canal and includes four 

seepage meters. No substantial change in land-surface 

altitude was observed along the GPR traverses except 

for artificial levees adjacent to canals.

Indian Mound Site

The GPR survey at the Indian Mound site 

contains imaging of surficial quartz sands, possibly 

quartz sands of the Tamiami Formation, and quartz 
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 29

? ? 

River bottom

Turn West

0

50

100150200

20

100

406080

120140160

0

DEPTH, IN FEET

USING 7,218 FEET

PER SECOND

200250300350400450500600550650700750

DEPTH, IN FEET

USING 5,578 FEET

PER SECOND

Hawthorn Group

limestone

Approximate depth to topof Suwannee Limestone

South

Prograding clinoforms (deltaic)

Upper Peace River Formation Downlap unconformity

Shot point 19,500 19,000 18,500 18,000 17,500 17,000 16,500 16,000 15,5

TWO-WAY TRAVELTIME, IN MILLISECONDS

5 1 KILOMETE

0.5

00 1 M

Figure 10. Seismic-reflection profile in San Carlos Bay (location shown in fig. 1). The same section of prograding clinoformal reflection 

other studies by Missimer and Gardner (1976), Scholz and Cunningham (1997), and assigned to the upper Peace River Formation by clinoformal reflections likely represent a southward prograding deltaic depositional system as suggested by Missimer (1999). Underlyinsurface are parallel reflections assigned to the lower Peace River Formation.
30 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

sands of the upper Peace River Formation (fig. 11) and 

the surficial aquifer system. Radar reflections assigned 

to the upper Peace River Formation have a parallel, 

oblique progradational configuration (fig. 11). The 

uppermost inclined radar reflections assigned to the 

upper Peace River Formation form a toplapping or 

erosional discordance with overlying horizontal parallel radar reflections tentatively assigned to the Tamiami Formation (fig. 11). Verification of assignment of 

the inclined reflections to the upper Peace River Formation is based on correlation of the GPR profile to 

the Caloosahatchee River seismic survey and nearby 

lithologic logs obtained from test wells W-12844 and 

W-16944 (fig. 1). The inclined radar facies present 

within the upper Peace River Formation (fig. 11) is 

probably indicative of moderate hydraulic conductivities for quartz sands (Fish, 1988, table 7), because 

samples from spoil banks around the sand pit suggest 

this facies lacks any significant clay matrix and is friable. The apparent angle on the south dipping seismic 

reflections is about 7 degrees. The parallel, oblique 

progradational pattern of radar reflections (fig. 11) 

may be images of the tops of progradational seismicreflection configurations that dip as much as 5 degrees 

in the easternmost part of survey segment 2 (fig. 3). 

Thus, GPR has potential to image the shallow part of 

the subsurface above the river bottom not imaged in 

the marine seismic-reflection profiles collected along 

the Caloosahatchee River. The reflection geometries 

displayed in the GPR profile (fig. 11) are interpreted to 

be low-angle, accretionary foreset beds associated 

with the depositional axis of the deltaic depositional 

system imaged in seismic-reflection profiles to the 

south along the Caloosahatchee River (fig. 3). 

Abundant discoid pebbles have been recovered 

from the spoil banks surrounding the sand pit and have 

been excavated possibly from equivalent strata. The 

possible presence of discoid pebbles within the southward dipping beds of the upper Peace River Formation 

(fig. 11) are consistent with deposition in foreshore, 

shoreface and offshore marine or channel-spit environments. Dobkins and Folk (1970) showed that the 

presence of discoid pebbles can be used as evidence of 

beach environments. 

CRS06 Site

A test corehole (HE-1118) was drilled to a depth 

of 22 ft at the CRS06 site (figs. 1 and 12) to obtain 

lithostratigraphic and hydraulic information about the 

shallow rock units of the surficial aquifer system. 

Horizontal, parallel radar reflections assigned to a surficial quartz sand onlap onto the sides of the lows on an 

undulatory radar reflection assigned to the top of the 

Caloosahatchee Formation (fig. 12). The radar facies 

of the Caloosahatchee Formation has a wavy, parallel 

to semiparallel, configuration with radar reflections of 

relatively moderate to high amplitude compared to 

overlying reflections of the surficial sand. 

The depth and continuity of the Caloosahatchee 

Formation is of hydrologic interest because these properties may influence drainage. At the CR06 site, four 

seepage meters were installed by Belanger (1999) to 

measure rates of exchange between canal water and 

ground water. The estimated stratigraphic positions of 

the basal contacts of seepage meters 1 and 2 with 

canal-bottom outcrops are correlated to intervals of no 

recovery in test corehole HE-1118 (fig. 12). Very high 

seepage rates are reported for seepage meter 2 

(fig. 13). Since correlation of the estimated depth and 

location of seepage meter 2 to test corehole HE-1118 

shows the meter is positioned over rocks or sediments 

that were not recovered in the test corehole, it is not 

possible to verify any geologic explanation for the relatively high seepage rates. However, based on samples 

of rock dredged from the canal during construction, the 

rock samples can have inch-scale diameter, semivertical, solution-enlarged porosity, it is possible that seepage meter 2 is seated above this type of large-scale 

pore network in the Caloosahatchee Formation. Seepage meters 1, 3, and 4 produced relatively low seepage 

rates (fig. 13). Correlation of the bottom position of 

seepage meter 1 to the GPR profile and test corehole 

HE-1118 suggests the meter is seated on the upper contact of the Caloosahatchee Formation (fig. 12). Correlation of the bottom position of seepage meters 3 and 4 

suggests these meters are seated in a shelly sandstone 

with low hydraulic conductivity (see appendix, test 

corehole HE-1118) at a depth of about 16 ft below 

ground level. Positioning of seepage meters 3 and 4 in 

a hydrogeologic unit with low hydraulic conductivity 

suggests that the relatively low seepage rates are geologically controlled. 

The combined use of data from seepage meters, 

GPR, and continuously drilled test coreholes can be 

used to gain an accurate understanding of subsurface 

hydraulic properties. Continuous borehole images can 

provide critical hydrogeologic information over zones 

of no core recovery, such as in this study where 

borehole images, if available, could have been used 
Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin 31 VERTICAL SCALE GREATLY EXAGGERATED 50 FEET

5 15 METERS

25

10

0

0

NORTH WATER TABLE(?) 

TOP UPPER PEACE RIVER 

INSTRUMENT NOISE

TOPLAP OR EROSIONAL

TRUNCATION(?)

0

100

500

400

300

200

DEPTH IN NANNOSECONDS

TWO-WAY TRAVELTIME

NORTH 

TAMIAMI TAMIAMI FORMATION(?) FORMATION(?)

SURFICIAL SANDS

UPPER PEACE

RIVER FORMATION

UPPER PEACE

RIVER FORMATION

0

100

500

400

300

200

DEPTH IN NANNOSECONDS

TWO-WAY TRAVELTIME

*Based on velocity of (1) unsaturated sand of 0.4(2) saturated sand of 0.20 feet per nannosecond 

Figure 11. Ground-penetrating radar profile and interpretation from the Indian Mound site in Glades County. The radar profile shows preflections that are interpreted to be images of low angle, accretionary foreset beds. This geophysical technique profiles a unique view inthe sediments, producing information that can be used for interpretation of depositional environments and hydraulic conductivity. A dee500 feet north of the profile, which suggests the entire profile is imaging a quartz sand lithology. (See fig. 1 for site location).
32 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla. SOUTH NORTH

DEPTH IN NANNOSECONDS

TWO-WAY TRAVELTIME

0

100200

CRS06

Well Cluster

WATER

TABLE

Top

Caloosahatchee

Formation

Possible

semivertical

solution

“pipe”

Direct

arrival

Test

corehole

HE-1118

51525

INSTRUMENT NOISE

*Based on velocity of (1) unsaturated sand of 0.39 foot per nannosecond,

(2) saturated sand of 0.24 foot per nannosecond, and (3) saturatedlimestone of 0.18 foot per nannosecond

SOUTH

DEPTH IN NANNOSECONDS

TWO-WAY TRAVELTIME

0

100200

Surficial quartz sand

Caloosahatchee Formation

Tamiami Formation

CRS06

Well Cluster

TEST

COREHOLE

HE-1118

NORTH

APPROXIMATE DEPTH*, IN FEET,

BELOW GROUND LEVEL

0

510201525

50 FEET

10 15 METERS

25

5

VERTICAL SCALE GREATLY EXAGGERATED

00

QUARTZ SANDSHELLY SANDSTONEPELECYPOD LIME RUDSTONE AND FLOATSTONEUNCONSOLIDATED PELECYPODS SHELLS

EXPLANATION

0

1020

APPROXIMATE DEPTH*, IN FEET,

BELOW GROUND LEVEL 

INTERVAL OF NO CORE RECOVERYLITHOSTRATIGRAPHIC BOUNDARY, DASHED WHERE APPROXIMATELY LOCATEDUNLAPPING BEDS

Figure 12. Correlation of ground-penetrating radar profile, test corehole HE-1118, and seepage meters at the CRS06 monitoring well sAll four seepage meters are seated in the Caloosahatchee Formation. (See fig. 1 for site location)
Summary and Conclusions 33

to accurately correlate between the seat position of 

seepage meters 1 and 2 and the core intervals that 

lacked recovery.

SUMMARY AND CONCLUSIONS

The Caloosahatchee River Basin, located in 

southwestern Florida, encompasses 1,200 mi2 of land. 

The Caloosahatchee River receives water from Lake 

Okeechobee, runoff from the watershed, and seepage 

from the ground-water systems; it loses water through 

drainage to the Gulf of Mexico and through withdrawals for public-water supply, agriculture, and natural 

needs. Projected water-supply needs indicate the 

Caloosahatchee River will not meet future demands, 

and the Caloosahatchee River Basin could be further 

stressed if the river water is used to accommodate restoration of the Everglades. Water managers and planners need to know how much water will be used within 

the Caloosahatchee River Basin and how much water is 

contributed by Lake Okeechobee, runoff, and ground 

water. In this study, marine seismic-reflection and GPR 

techniques were used to support evaluation of potential 

exchange of water between the river and ground-water 

systems. Seven test coreholes were drilled to calibrate 

lithostratigraphic units and their estimated hydraulic 

conductivities to surface-geophysical profiles. 

A continuous marine seismic-reflection survey 

was collected over much of the entire Caloosahatchee 

River and part of San Carlos Bay. Subhorizontal reflections assigned to the Tamiami Formation intersect the 

river bottom along a 9-mi segment just west of Moore 

Haven. In an area between the western side of Lake 

Hicpochee and La Belle, oblique and sigmoidal progradational reflections assigned to the upper Peace 

River Formation probably intersect the floor of the 

river. These progradational reflections image a regionalscale deltaic depositional system containing quartz 

sands with low to moderate estimated hydraulic conductivities. For a 6-mi length of the river between 

La Belle and Franklin Lock, deeper structures possibly 

created by karstic collapse influence the geometries of 

parallel reflections that intersect the river channel. 

Here, reflections assigned to the Buckingham Limestone Member of the Tamiami Formation, a confining 

unit, and reflections assigned to the clastic zone of the 

sandstone aquifer are likely connected with the river 

bottom. Beneath these shallow reflections, relatively 

higher amplitude parallel reflections of the carbonate 

zone of the sandstone aquifer are well displayed in the 

0.0001

0.001

0.01

0.1

1.0

Oct 1998

SEEPAGE, IN GALLONS PER

SQUARE FEETPER HOUR

Nov 1998 Dec 1998 Jan 1999

DATE

SEEPAGE METER 1 SEEPAGE METER 2

SEEPAGE METER 3 SEEPAGE METER 4

Figure 13. Average ground-water seepage data collected at the CRS06 monitoring well site in 

Hendry County, October 1998 to January 1999. Data collected by Belanger (1999). Original units 

were in milliliters per square meter per hour.
34 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

seismic-reflection profiles. A deltaic depositional 

system that displays oblique progradational reflections 

assigned to the upper Peace River Formation underlies 

San Carlos Bay. Almost everywhere beneath the river, 

a diffuse ground-water flow system is in contact with 

the channel bottom. Between Ortona Lock and Lake 

Hicpochee, however, limestones of the Tamiami Formation may intersect the river channel, suggesting 

local conduit flow between the surface and groundwater systems.

The GPR profiles of an area about 2 mi north of 

the depositional axis of the deltaic depositional system 

between Lake Hicpochee and La Belle show that the 

progradational clinoforms seen in seismic records 

from the Caloosahatchee River are present within 

about 17 ft of the ground surface. The GPR profiles 

show that the uppermost southward dipping, oblique 

progradational reflections of the Peace River Formation are terminated by a toplapping or erosional discontinuity. These clinoformal reflections represent 

clean quartz sands that are probably characterized by 

moderate hydraulic conductivity. The areal distribution of the clinoformal reflections could be mapped 

using GPR methods. 

In general, results of this study indicate that:

• Seismic-reflection profiles are necessary to accurately correlate hydrogeologic units between 

wells because the geometries of south Florida 

hydrostratigraphic units contain complex stratal 

geometries;

• Seismic-reflection profiles can be used to image 

and map the boundary between the clastic zone 

and carbonate zone of the sandstone aquifer, 

which is part of the intermediate aquifer system;

• Seismic-reflection profiles can be used to infer the 

distribution and quality of the connection 

between the bottom of the Caloosahatchee River 

and ground-water systems;

• Seismic-reflection profiles are useful in defining 

regional-scale depositional systems that are templates for the regional-scale hydraulic properties 

of the regional ground-water systems;

• Shallow collapse structures within the Peace River 

and Arcadia Formations that could be related to 

karst within the limestone of the Floridan aquifer 

system can be imaged with seismic-reflection 

methods;

• GPR methods have potential to image the shallow 

portion of the subsurface above the Caloosahatchee River bottom, which was not imaged in 

the marine seismic-reflection profiles;

• GPR profiles can be useful in defining depositional 

environments of near-surface siliciclastics, and 

thus, used in mapping the shallow distribution 

and degree of the permeability of a ground-water 

system; and 

• Understanding the connection between seepage 

meters and hydraulic properties of the subsurface 

rocks is possible by combining GPR methods, 

continuous test coreholes, and continuous borehole images.

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Appendix--Litholotic Descriptions 37

APPENDIX

Lithologic Descriptions of

Cores Drilled for This Study

[Items in the descriptions are arranged in the following order: rock type with 

modifiers, color, grain size, sorting, roundness, accessory grains, porosity, 

hydraulic conductivity, environment, and comments. However, not all of 

these items are included in every description. Latitude and longitude datums 

NAD 83]

Local well identifier

GL-323

GL-325

GL-326

GL-327

GL-329

HE-1118

L-5809
38 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

GL-323 Test Corehole

Florida Geological Survey well number W-18069

GWSI number GL-323

Total depth 401 feet

Cored from 0 to 401 feet

County Glades

Location SE, sec. 25, T42S, R29E

Latitude 26° 47′ 38′′

Longitude 81° 21′ 42.5′′

Elevation 21 feet

Completion date May 7, 1999

Other types of logs available Resistivity, gamma ray, spontaneous potential

Owner U.S. Geological Survey

Driller Florida Geological Survey

Core described by Kevin J. Cunningham

Fill 0 to 10 feet

Lake Flirt Marl Formation 10 to 10.9 feet

Undifferentiated 10.9 to 25 feet

Tamiami Formation 25 to 47(?) feet

Upper Peace River Formation 47(?) to 225.2 feet

Lower Peace River Formation (?) 225.2 to 255.3 feet

Arcadia Formation 255.3 to 401 feet

Water-table aquifer 0 to 38(?) feet
Appendix--Litholotic Descriptions, Core GL-323 39

Depth

(feet below 

land surface)

Lithologic description of GL-323 test corehole

0.0-10.0 Fill.

10.0-10.9 Quartz sand interbedded with gastropod lime wackestone; moderate yellowish brown 10YR 6/2; mainly very fine to fine 

quartz sand; Helisoma gastropods; 25 percent intergrain porosity; moderate hydraulic conductivity; friable.

10.9-19.3 No recovery.

19.3-25.0 Mixed lithology of quartz sand and pelecypods and gastropods; probably caved sediments.

25.0-26.0

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly very fine to fine quartz sand; minor 

very fine to fine phosphorite and heavy mineral grains; trace clay; 2 percent phosphorite and heavy mineral grains; 25 percent 

intergrain porosity; moderate hydraulic conductivity; friable; trace clay matrix.

26.0-37.0 No recovery.

37.0-38.0 Caved sand and shells.

38.0-38.8

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly very fine to fine quartz sand; minor 

sand- to pebble-sized fossils, terrigenous clay, and very fine to fine phosphorite and heavy mineral grains; abundant pelecypod shells and fragments; 2 percent phosphorite and heavy mineral grains; 20 percent intergrain porosity; low hydraulic 

conductivity; friable, minor clay matrix.

38.8-42.0

Quartz sand; very light gray N8 and yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly very fine to 

fine quartz sand; minor sand- to pebble-sized fossils, clay and lime mud, and very fine to fine phosphorite and heavy mineral 

grains; abundant pelecypod shells and fragments; minor barnacles; 2 percent phosphorite and heavy mineral grains; 15 percent intergrain porosity; low hydraulic conductivity: friable; minor clay and lime mud matrix.

42.0-47.0

Quartz sand; very light gray N8 and yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly very fine to 

fine quartz sand; minor medium quartz sand, sand- to pebble-sized fossils, clay and lime mud, and very fine to fine phosphorite and heavy mineral grains; minor pelecypod shells and fragments; 2 percent phosphorite and heavy mineral grains; trace 

mica; 20 percent intergrain porosity; low hydraulic conductivity; friable; minor clay and lime mud matrix.

47.0-49.0

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly very fine to fine quartz sand; minor 

terrigenous clay, and very fine to fine phosphorite and heavy mineral grains; 2 percent phosphorite and heavy mineral grains; 

trace mica; 20 percent intergrain porosity; low hydraulic conductivity; friable; minor clay matrix.

49.0-51.5 No recovery.

51.5-54.5 Caved sediments.

54.5-61.0

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly very fine to fine quartz sand; minor 

very fine to fine phosphorite and heavy mineral grains; trace terrigenous clay; 2 percent phosphorite and heavy mineral 

grains; trace mica; 25 percent intergrain porosity; moderate hydraulic conductivity; friable; trace clay matrix; bioturbated.

61.0-69.0

Quartz sand; yellowish gray 5Y 7/2 and light olive gray 5Y 5/2; black N1 phosphorite and heavy minerals; mainly very fine 

to fine quartz sand; minor terrigenous clay and very fine to fine phosphorite and heavy mineral grains; 2 percent phosphorite 

and heavy mineral grains; trace mica; 10-15 percent intergrain porosity; low hydraulic conductivity; soft; minor clay matrix; 

irregular, disrupted clay laminations; bioturbated.

69.0-70.0 No recovery.

70.0-84.0

Quartz sand; yellowish gray 5Y 7/2 and light olive gray 5Y 5/2; black N1 phosphorite and heavy minerals; mainly very fine 

to fine quartz sand; minor terrigenous clay and very fine to fine phosphorite and heavy mineral grains; 2 percent phosphorite 

and heavy mineral grains; trace mica; 10-15 percent intergrain porosity; low hydraulic conductivity; soft; minor clay matrix; 

irregular, disrupted clay laminations; bioturbated.

84.0-85.0 No recovery.

85.0-102.0

Quartz sand; yellowish gray 5Y 7/2 and light olive gray 5Y 5/2; black N1 phosphorite and heavy minerals; mainly very fine 

quartz sand; minor fine quartz sand, terrigenous clay and very fine to fine phosphorite and heavy mineral grains; 2-4 percent 

phosphorite and heavy mineral grains; trace mica; 10-15 percent intergrain porosity; low hydraulic conductivity; soft; minor 

clay matrix; irregular, disrupted clay laminations; bioturbated.
40 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

102.0-105.6

Interbedded quartz sand and diatomaceous mudstone; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; 

mainly very fine quartz sand and terrigenous clay; minor very fine to fine phosphorite and heavy mineral grains; diatoms; 

5-15 percent phosphorite and heavy mineral grains; trace mica; 5-15 percent intergrain porosity; very low hydraulic conductivity.

105.6-108.0 No recovery.

108.0-123.5

Diatomaceous mudstone; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly terrigenous clay; minor 

silt and very fine quartz sand, and very fine to fine phosphorite and heavy mineral grains; diatoms; 2-10 percent phosphorite 

and heavy mineral grains; trace mica; 5 percent microporosity; very low hydraulic conductivity; minor interbedding with very 

fine quartz sand.

123.5-125.0 No recovery.

125.0-130.0

Diatomaceous mudstone; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly terrigenous clay; minor 

silt and very fine quartz sand, and very fine to fine phosphorite and heavy mineral grains; diatoms; 2-10 percent phosphorite 

and heavy mineral grains; trace mica; 5 percent microporosity; very low hydraulic conductivity; minor interbedding with very 

fine quartz sand.

130.0-133.0

Quartz sand; yellowish gray 5Y 7/2 and light olive gray 5Y 5/2; black N1 phosphorite and heavy minerals; mainly very fine 

to fine quartz sand; minor terrigenous clay and very fine to fine phosphorite and heavy mineral grains; 2-15 percent phosphorite and heavy mineral grains; trace mica; 10 percent intergrain porosity; low hydraulic conductivity; friable; mainly fine to 

coarse quartz sand at base of unit.

133.0-140.0

Diatomaceous mudstone; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly terrigenous clay, silt and 

very fine quartz sand; minor very fine to medium phosphorite and very fine heavy mineral grains; diatoms; 2-20 percent 

phosphorite and heavy mineral grains; trace mica; 5 percent microporosity; very low hydraulic conductivity.

140.0-145.0

Diatomaceous mudstone interlaminated with quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; 

mainly terrigenous clay, silt and very fine quartz sand; minor fine to coarse quartz sand, very fine to medium phosphorite, and

very fine heavy mineral grains; diatoms; 2-20 percent phosphorite and heavy mineral grains; trace mica; 5 percent 

microporosity; very low hydraulic conductivity.

145.0-151.0 No recovery.

151.0-160.0

Diatomaceous mudstone interlaminated with quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; 

mainly terrigenous clay, silt and very fine quartz sand; minor fine to coarse quartz sand, very fine to medium phosphorite, and

very fine heavy mineral grains; diatoms; 2-20 percent phosphorite and heavy mineral grains; trace mica; 5 percent 

microporosity; very low hydraulic conductivity.

160.0-170.0

Quartz sand with very minor interlaminations of diatomaceous mudstone; yellowish gray 5Y 7/2; black N1 phosphorite and 

heavy minerals; mainly medium to coarse quartz sand; minor silt to fine quartz sand, terrigenous clay, very fine to coarse 

phosphorite, and very fine heavy mineral grains; diatoms; trace to 5 percent phosphorite and heavy mineral grains; trace 

mica; 20-25 percent intergrain porosity; low to moderate hydraulic conductivity; minor clay matrix.

170.0-180.5

Quartz sand with very minor interlaminations of diatomaceous mudstone; yellowish gray 5Y 7/2; black N1 phosphorite and 

heavy minerals; mainly fine to medium quartz sand; minor silt to very fine quartz and coarse sand, terrigenous clay, very fine 

to medium phosphorite, and very fine heavy mineral grains; trace to 5 percent phosphorite and heavy mineral grains; trace 

mica; 20-25 percent intergrain porosity; low to moderate hydraulic conductivity; minor clay matrix.

180.5-181.0 No recovery.

181.0-189.5

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly fine to medium quartz sand; minor silt 

to very fine quartz sand, terrigenous clay, very fine to medium phosphorite, and very fine heavy mineral grains; trace to 5 percent phosphorite and heavy mineral grains; trace mica; 20-25 percent intergrain porosity; low to moderate hydraulic conductivity; minor clay matrix.

189.5-191.0 No recovery.

191.0- 219.5

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly very fine to fine quartz sand; minor 

silt quartz sand, terrigenous clay, very fine to fine phosphorite, and very fine heavy mineral grains; 5-20 percent phosphorite

and heavy mineral grains; trace mica; 20-25 percent intergrain porosity; low hydraulic conductivity; minor clay matrix; bioturbated; very fine laminations of terrigenous mudstone between 203 and 203.4 feet; thin white pelecypod shells at 217.75.

Depth

(feet below 

land surface)

Lithologic description of GL-323 test corehole
Appendix--Litholotic Descriptions, Core GL-323 41

219.5-221.6

Quartz sand interlaminated with terrigenous mudstone; yellowish gray 5Y 7/2, light olive gray 5Y 5/2, olive gray 5Y 4/1; 

black N1 phosphorite and heavy minerals; mainly very fine to fine quartz sand and terrigenous clay; minor silt quartz sand, 

very fine to fine phosphorite, and very fine heavy mineral grains; 5-20 percent phosphorite and heavy mineral grains; trace 

mica; <5-25 percent intergrain porosity; very low hydraulic conductivity.

221.6-224.3

Terrigenous mudstone with minor interbeds of quartz sand; olive gray 5Y 3/2, yellowish gray 5Y 7/2; black N1 phosphorite 

and heavy minerals; mainly terrigenous clay; minor silt-sized and very fine to fine quartz sand, very fine to fine phosphorite,

and very fine heavy mineral grains; 5-20 percent phosphorite and heavy mineral grains; trace mica; 20 percent intergrain 

porosity in quartz sand; very low hydraulic conductivity.

224.3-225.2

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy minerals; mainly very fine to fine quartz sand; minor 

silt-sized and medium to small pebble-sized quartz sand, very fine sand- and small pebble-sized phosphorite, and very fine 

heavy mineral grains; 20-30 percent phosphorite and heavy mineral grains; trace mica; 20 percent intergrain porosity; low 

hydraulic conductivity.

225.2-231.0

Dolosilt, terrigenous mudstone and quartz silt; yellowish gray 5Y 7/2; mainly very fine quartz sand, quartz silt, dolosilt and 

clay; minor silt-sized and fine sand, very fine to coarse phosphorite grains, and very fine heavy mineral grains; 5-30 percent 

phosphorite and heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; trace very thin, white 

pelecypod shells.

231.0-244.1

Silty and sandy terrigenous mudstone and quartz silt; yellowish gray 5Y 7/2; mainly very fine quartz sand, quartz silt and 

clay; minor silt-sized and fine sand, very fine to coarse phosphorite grains, and very fine heavy mineral grains; 5-30 percent 

phosphorite and heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; trace very thin, white 

pelecypod shells.

244.1-248.1

Lime mudstone with abundant phosphorite grains; yellowish gray 5Y 7/2 to white N9; black N1 phosphorite grains produce a 

salt and pepper appearance; mainly clay-sized lime mud and very fine phosphorite grains; minor silt-sized and very fine sand, 

very fine heavy mineral grains, and fine to medium phosphorite grains; 30-50 percent phosphorite and trace heavy mineral 

grains; 5 percent microporosity; very low hydraulic conductivity; chalky texture.

248.1-251.0 No recovery.

251-253.3

Quartz sand and phosphorite with micrite matrix; yellowish gray 5Y 7/2 to white N9; black N1 phosphorite grains produce a 

salt and pepper appearance; mainly clay-sized lime mud, very fine phosphorite grains, and silt-sized and very fine sand, very 

fine heavy mineral grains, and fine to medium phosphorite grains; 30-50 percent phosphorite and trace heavy mineral grains; 

5 percent microporosity; very low hydraulic conductivity; chalky texture.

253.3-259.4

Lime mudstone with abundant phosphorite grains; pale greenish yellow to white N9; black N1 phosphorite grains; mainly 

clay-sized lime mud and very fine phosphorite grains; very fine heavy mineral grains, and fine to medium phosphorite grains; 

5-40 percent phosphorite and trace heavy mineral grains; minor pelecypods; 5 percent microporosity; very low hydraulic 

conductivity; chalky texture; abrupt contact and possible erosional discontinuity at 255.3 feet.

259.4-261.0 No recovery.

261.0-268.7

Lime mudstone and pelecypod floatstone with lime mudstone matrix; pale greenish yellow 10Y 8/2 to yellowish gray 5Y 7/2 

to white N9; black N1 phosphorite grains; mainly clay-sized lime mud and very fine to fine phosphorite grains; minor very 

fine to fine quartz sand, very fine heavy mineral grains, medium sand- to very small pebble-sized phosphorite grains, and 

pebble-sized pelecypods; 5-40 percent phosphorite and trace heavy mineral grains; 10-20 percent quartz sand; trace 

bryozoans; 5 percent microporosity; very low hydraulic conductivity; chalky texture; abrupt contact at 266.9 feet; up to large 

pebble-sized phosphate pebbles between 268.6 and 268.7 feet.

268.7-269.0

Lime mudstone and bryozoan floatstone with lime mudstone matrix; yellowish gray 5Y 7/2 to white N9; black N1 phosphorite grains; mainly clay-sized lime mud and very fine to fine phosphorite grains; minor very fine heavy mineral grains, 

medium sand- to very small pebble-sized phosphorite grains, and pebble-sized bryozoans; 5-20 percent phosphorite and trace 

heavy mineral grains; bryozoans (including chielostomes and Cyclostomata) 5 percent microporosity; very low hydraulic 

conductivity; chalky texture; irregular abrupt contact with 1-mm thick blackened crust at top (268.7 feet) and up to 2 centimeters of microtopography; probable top of Arcadia.

269.0-271.0 No recovery.

Depth

(feet below 

land surface)

Lithologic description of GL-323 test corehole
42 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

271.0-276.3

Lime mudstone and bryozoan floatstone with lime mudstone matrix; yellowish gray 5Y 7/2 to white N9; black N1 phosphorite grains; mainly clay-sized lime mud and very fine to fine phosphorite grains; minor very fine heavy mineral grains, 

medium sand- to very small pebble-sized phosphorite grains, and pebble-sized bryozoans; 5-20 percent phosphorite and trace 

heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; chalky texture; bryozoans between 271 and 

273.5 feet.

276.3-278.0 No recovery.

278.0-280.5

Interbedded lime mudstone and oyster lime floatstone with lime mudstone matrix; yellowish gray 5Y 7/2 to white N9; black 

N1 phosphorite grains; mainly clay-sized lime mud and very fine to fine phosphorite grains; minor very fine heavy mineral 

grains; 5-20 percent phosphorite and trace heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; 

chalky texture.

280.5-281.0 No recovery.

281.0-287.7

Interbedded lime mudstone, dolosilt and pelecypod lime floatstone with lime mudstone matrix; yellowish gray 5Y 7/2 to 

white N9; black N1 phosphorite grains; mainly clay-sized lime mud, silt-sized dolomite and very fine to fine phosphorite 

grains; minor medium sand- and small pebble-sized phosphorite grains, and very fine heavy mineral grains; 5-30 percent 

phosphorite and trace heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; moldic pelecypods; 

bioturbated; abundant intraclasts of lithology between 288 and 292 feet.

287.7-288.0 No recovery.

288.0-292.0

Dolosilt; yellowish gray 5Y 8/1; black N1 phosphorite grains; mainly silt-sized dolomite; minor very fine to fine phosphorite 

grains and very fine heavy mineral grains; trace to 5 percent phosphorite and trace heavy mineral grains; 5 percent 

microporosity; very low hydraulic conductivity; possible unconformity between 287.7 and 288 feet.

292.0-297.0

Terrigenous mudstone; pale olive 5Y 6/2; black N1 phosphorite grains; mainly clay; minor very fine to fine phosphorite 

grains and very fine heavy mineral grains; trace to 5 percent phosphorite and trace heavy mineral grains; 5 percent 

microporosity; very low hydraulic conductivity; horizontal laminations; up to large pebble-sized chert clasts in lower 1⁄2 inch 

of interval.

297.0-299.0

Terrigenous mudstone; yellowish gray 5Y 7/2, light olive gray 5Y 5/2; black N1 phosphorite grains; mainly clay; minor very 

fine to medium phosphorite grains and very fine heavy mineral grains; 5-20 percent phosphorite and trace heavy mineral 

grains; 5 percent microporosity; very low hydraulic conductivity.

300.0-306.0

Pelcypod lime floatstone and lime wackestone; pale olive 10 Y 6/2, yellowish gray 5Y 7/2 to white N9; black N1 phosphorite 

grains; mainly clay-sized lime mud; minor very fine to medium phosphorite grains, very fine heavy mineral grains, and pebble-sized fossils; 5-20 percent phosphorite and trace heavy mineral grains; minor pelecypods, bryozoans and gastropods; 

5 percent microporosity; very low hydraulic conductivity.

306.0-324.0

Interbedded phosphorite sand with lime mudstone matrix, pelecypod lime floatstone with lime mudstone matrix, and lime 

mudstone with abundant phosphorite grains; pale olive 10 Y 6/2, yellowish gray 5Y 7/2, olive gray 5Y 3/2; black N1 and 

light olive gray 5Y 5/2 phosphorite grains; mainly very fine to fine phosphorite grains and clay-sized lime mud; minor 

medium to coarse phosphorite grains, very fine heavy mineral grains, and pebble-sized fossils; 20-75 percent phosphorite and 

trace heavy mineral grains; minor pelecypods; 5 percent microporosity; very low hydraulic conductivity.

324.0-328.0

Lime mudstone with abundant phosphorite grains and pelecypod lime floatstone with lime mudstone matrix; yellowish gray 

5Y 8/1; black N1 and light olive gray 5Y 5/2 phosphorite grains; mainly clay-sized lime mud; minor very fine to fine phosphorite grains, very fine heavy mineral grains, and pebble-sized fossils; 10-20 percent phosphorite and trace heavy mineral 

grains; minor pelecypods and gastropods; 5 percent microporosity; very low hydraulic conductivity.

328.0-331.0 No recovery.

331.0-341.0

Lime mudstone with abundant phosphorite grains and pelecypod lime floatstone with lime mudstone matrix; yellowish gray 

5Y 8/1; black N1 and light olive gray 5Y 5/2 phosphorite grains; mainly clay-sized lime mud; minor very fine to fine phosphorite grains, very fine heavy mineral grains, and pebble-sized fossils; 10-20 percent phosphorite and trace heavy mineral 

grains; minor pelecypods and gastropods; 5 percent microporosity; very low hydraulic conductivity.

341.0-351.0

Lime mudstone with abundant phosphorite grains and pelecypod lime floatstone with lime mudstone matrix; yellowish gray 

5Y 8/1; black N1 and light olive gray 5Y 5/2 phosphorite grains; mainly clay-sized lime mud; minor very fine to fine phosphorite grains, and very fine heavy mineral grains; 10-20 percent phosphorite and trace heavy mineral grains; 5 percent 

microporosity; very low hydraulic conductivity.

Depth

(feet below 

land surface)

Lithologic description of GL-323 test corehole
Appendix--Litholotic Descriptions, Core GL-323 43

351.0-359.0

Quartz and phosphorite sand; yellowish gray 5Y 7/2; black N1 and light olive gray 5Y 5/2 phosphorite grains; mainly silt- to 

very fine sand-sized quartz grains and very fine phosphorite grains; minor very fine heavy mineral grains; 50 percent phosphorite and trace heavy mineral grains; 10 percent intergrain porosity; low hydraulic conductivity; abundant dolosilt and 

terrigenous mudstone matrix.

359.0-359.2

Lime mudstone with abundant phosphorite grains and pelecypod lime floatstone with lime mudstone matrix; yellowish gray 

5Y 8/1; black N1 and light olive gray 5Y 5/2 phosphorite grains; mainly clay-sized lime mud; minor very fine to fine phosphorite grains, and very fine heavy mineral grains; 10-20 percent phosphorite and trace heavy mineral grains; 5 percent 

microporosity; very low hydraulic conductivity.

359.2-361.0 No recovery.

361.0-370.0

Lime mudstone with abundant phosphorite grains and pelecypod lime floatstone with lime mudstone matrix; yellowish gray 

5Y 8/1; black N1 and light olive gray 5Y 5/2 phosphorite grains; mainly clay-sized lime mud; minor very fine to fine phosphorite grains, and very fine heavy mineral grains; 10-20 percent phosphorite and trace heavy mineral grains; 5 percent 

microporosity; very low hydraulic conductivity.

370.0-371.0

Dolosilt; yellowish gray 5Y 7/2; black N1 and light olive gray 5Y 5/2 phosphorite grains; mainly silt-sized dolomite; minor 

very fine to fine phosphorite grains and very fine heavy mineral grains; trace to 5 percent phosphorite and trace heavy mineral

grains; 5 percent microporosity; very low hydraulic conductivity.

371.0-377.8 Terrigenous mudstone; olive gray 5Y 3/2; mainly clay-sized terrigenous clay; 5 percent microporosity; very low hydraulic 

conductivity; very fine horizontal laminations.

377.8-379.0

Phosphorite sand with terrigenous clay matrix; yellowish gray 5Y 7/2; black N1 and light olive gray 5Y 5/2 phosphorite 

grains; mainly very fine to medium sand-sized phosphorite grains; minor coarse to small pebble-sized phosphorite grains; 

clay-sized terrigenous clay; 90 percent phosphorite and trace heavy mineral grains; 10 percent intergrain porosity; low 

hydraulic conductivity.

37.9.0-401.0 No recovery.

Depth

(feet below 

land surface)

Lithologic description of GL-323 test corehole
44 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

GL-325 Test Corehole

Florida Geological Survey well number W-18070

GWSI number GL-325

Total depth 200.5 feet

Cored from 0 to 200.5 feet

County Glades

Location NW, SE, sec. 35, T42S, R29E

Latitude 26° 46′ 21.5′′

Longitude 81° 23′ 37.9′′

Elevation 25.5 feet

Completion date June 19, 1999

Other types of logs available Induction, gamma ray, resistivity, spontaneous potential

Owner U.S. Geological Survey

Driller Florida Geological Survey

Core described by Kevin J. Cunningham

Fill 0 to 15.9 feet

Lake Flirt Marl Formation 15.9 to 18.6 feet

Undifferentiated Fort Thompson, Caloosahatchee 18.6 to 22.5 feet

Tamiami Formation 22.5 to 22.6 feet

Upper Peace River Formation 22.6 to 128.3 feet

Lower Peace River Formation 128.3 to 200.5 feet

Water-table aquifer 0 to 55 feet
Appendix--Litholotic Descriptions, Core GL-325 45

Depth

(feet below 

land surface)

Lithologic description of GL-325 test corehole

0.0-0.5 No recovery.

0.5-3.4 Fill.

3.4-5.0 No recovery.

5.0-7.6 Fill.

7.6-10.0 No recovery.

10.0-13.0 Fill.

13.0-15.0 No recovery.

15.0-15.9 Fill.

15.9-16.6 Marl; yellowish gray 5Y 8/1; mainly clay-sized micrite and silt and very fine to fine quartz sand; well sorted; subangular to 

subrounded; 20 percent quartz sand; 15 percent moldic porosity; very low hydraulic conductivity; soft wet; hard dry.

16.6-18.6

Quartz sand; dark yellowish brown 10YR 4/2; mainly very fine to medium quartz sand; trace clay; well sorted; subangular to 

subrounded; 20 percent quartz sand; trace clay; 25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; 

unconsolidated; abundant organics.

18.6-18.8

Pelecypod-rich quartz sand yellowish gray 5Y 7/2; mainly fine to medium quartz sand; minor medium to pebble-sized fossils; 

well sorted; subangular to subrounded; 45 percent pelecypods (including Chione); 25 percent intergrain porosity; moderate 

hydraulic conductivity; soft wet.

18.8-20.0 No recovery.

20.0-21.6 Caved quartz sand from Lake Flirt Formation.

21.6-22.5

Pelcypod-rich quartz sand; yellowish gray 5Y 7/2; mainly fine to medium quartz sand; minor medium to pebble-sized fossils; 

well sorted; subangular to subrounded; 45 percent pelecypods (including Chione); 25 percent intergrain porosity; moderate 

hydraulic conductivity; soft wet.

22.5-22.6

Pelecypod lime floatstone with quartz sand-rich lime mudstone matrix; dark gray to medium dark gray N3 to N4; mainly fine 

quartz sand; minor medium to very coarse quartz sand and medium to pebble-sized fossils; well sorted; subangular to subrounded; 45 percent quartz sand; 15 percent pelecypods; 5 percent moldic porosity; low hydraulic conductivity; very hard 

wet; well consolidated.

22.6-30.0 No recovery (driller reports that this interval is “soft” quartz sand based rig response while drilling interval).

30.0-30.8

Quartz sand; light olive gray 5Y 6/1; black N1 phosphorite and heavy mineral grains; mainly fine to medium quartz sand; 

minor quartz silt to very fine and coarse to very coarse quartz sand, and very fine to fine phosphorite and heavy mineral 

grains; moderately sorted; subangular to subrounded; 5 percent mainly phosphorite and subordinate heavy mineral grains; 

25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; very poorly consolidated.

30.8-36.9

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly fine to medium quartz sand; 

minor quartz silt to very fine and coarse to very coarse quartz sand, and very fine to fine phosphorite and heavy mineral 

grains; moderately sorted; subangular to subrounded; 5 percent mainly phosphorite and subordinate heavy mineral grains; 

25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; very poorly consolidated.

36.9-37.5 No recovery.

37.5-39.9

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly fine to medium quartz sand; 

minor quartz silt to very fine and coarse to very coarse quartz sand, and very fine to fine phosphorite and heavy mineral 

grains; moderately sorted; subangular to subrounded; 5 percent mainly phosphorite and subordinate heavy mineral grains; 

25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; very poorly consolidated.

39.9-40.5 No recovery.
46 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

40.5-42.0

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly fine to medium quartz sand; 

minor quartz silt to very fine and coarse to very coarse quartz sand, and very fine to fine phosphorite and heavy mineral 

grains; moderately sorted; subangular to subrounded; 5 percent mainly phosphorite and subordinate heavy mineral grains; 

25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; very poorly consolidated.

42.0-47.0

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly very fine to medium quartz sand; 

minor quartz silt to coarse quartz sand and very fine to fine phosphorite and heavy mineral grains; moderately to well sorted; 

subangular to subrounded; 5-10 percent mainly phosphorite and subordinate heavy mineral grains; 25 percent intergrain 

porosity; moderate hydraulic conductivity; soft wet; very poorly consolidated; trace coarse sand grains.

47.0-48.0 No recovery.

48.0-50.0

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly very fine to medium quartz sand; 

minor quartz silt and coarse quartz sand, and very fine to fine phosphorite and heavy mineral grains; moderately to well 

sorted; subangular to subrounded; 5-10 percent mainly phosphorite and subordinate heavy mineral grains; 25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; very poorly consolidated; trace coarse sand grains.

50.0-54.5

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy mineral grains; mainly very fine to fine quartz sand; 

minor quartz silt and medium to coarse quartz sand, very fine phosphorite and heavy mineral grains; well sorted; subangular 

to subrounded; 10 percent mainly phosphorite and subordinate heavy mineral grains; trace mica; 25 percent intergrain porosity; 

moderate hydraulic conductivity; soft wet; very poorly consolidated; trace medium to coarse quartz grains.

54.5-55.0 No recovery.

55.0-59.4

Quartz sand; yellowish gray 5Y 7/2; light olive gray 5Y 5/2 and olive gray 5Y 3/2 clay; black N1 phosphorite and heavy 

mineral grains; mainly very fine to fine quartz sand; minor quartz silt and medium quartz sand, very fine phosphorite and 

heavy mineral grains; well sorted; subangular to subrounded; 10-15 percent mainly phosphorite and subordinate heavy 

mineral grains; trace mica; 20 percent intergrain porosity; low hydraulic conductivity; soft wet; very poorly consolidated; 

common irregular thin (<1 mm thick) clay laminations and trace clay matrix; trace medium quartz grains.

59.4-60.0 No recovery.

60.0-68.9

Quartz sand; yellowish gray 5Y 7/2 sand; light olive gray 5Y 5/2 and olive gray 5Y 3/2 clay; black N1 phosphorite and heavy 

mineral grains; mainly very fine quartz sand; minor quartz silt and fine quartz sand, very fine phosphorite and heavy mineral 

grains; well sorted; mainly angular to subangular and subordinate subrounded; 10-15 percent mainly phosphorite and subordinate heavy mineral grains; trace mica; 20 percent intergrain porosity; low hydraulic conductivity; soft wet; very poorly 

consolidated; minor irregular thin (<1-3 mm thick) clay laminations, clay-rich sand laminations and clay matrix; trace 

medium quartz grains.

68.9-70.5 No recovery.

70.5-77.0

Quartz sand; yellowish gray 5Y 7/2 sand; black N1 phosphorite and heavy mineral grains; mainly very fine to fine quartz 

sand; minor quartz silt and medium to very coarse quartz sand, very fine phosphorite and heavy mineral grains; well to moderate sorted; mainly angular to subangular very fine to fine quartz grains and subangular to subrounded quartz sand; 10-15 

percent mainly phosphorite and subordinate heavy mineral grains; trace mica; 20 percent intergrain porosity; low hydraulic 

conductivity; soft wet; very poorly consolidated; minor thin clay-rich sand laminations; minor medium to coarse quartz grains 

floating in fine to very fine matrix; trace very coarse quartz grains; approximately 10 degrees inclined planar thinly laminated 

quartz sand between 73.5 and 75.5 feet.

77.0-80.2

Quartz sand; yellowish gray 5Y 7/2 sand; light olive gray 5Y 5/2 and olive gray 5Y 3/2 clay; black N1 phosphorite and heavy 

mineral grains; mainly very fine to fine quartz sand; minor quartz silt and very fine phosphorite and heavy mineral grains; 

well sorted; mainly angular to subangular and subordinate subrounded; 10-15 percent mainly phosphorite and subordinate 

heavy mineral grains; trace mica; 15-20 percent intergrain porosity; low hydraulic conductivity; soft wet; poorly consolidated; minor irregular thin clay laminations; common clay and dolosilt(?) matrix; common burrows.

80.2-80.5 No recovery.

80.5 - 84.0

Quartz sand; yellowish gray 5Y 7/2 sand; light olive gray 5Y 5/2 and olive gray 5Y 3/2 clay; black N1 phosphorite and heavy 

mineral grains; mainly very fine to fine quartz sand; minor quartz silt and very fine phosphorite and heavy mineral grains; 

well sorted; mainly angular to subangular and subordinate subrounded; 10-15 percent mainly phosphorite and subordinate 

heavy mineral grains; trace mica; 15-20 percent intergrain porosity; low hydraulic conductivity; soft wet; poorly consolidated; minor irregular thin clay laminations; common clay and dolosilt(?) matrix; common burrows.

Depth

(feet below 

land surface)

Lithologic description of GL-325 test corehole
Appendix--Litholotic Descriptions, Core GL-325 47

84.0-86.7

Quartz sand; yellowish gray 5Y 7/2 and light olive gray 5Y 5/2; black N1 phosphorite and heavy mineral grains; mainly very 

fine to fine quartz sand; minor quartz silt and very fine phosphorite and heavy mineral grains; well sorted; mainly angular to 

subangular and subordinate subrounded; 10-15 percent mainly phosphorite and subordinate heavy mineral grains; trace mica; 

10-15 percent intergrain porosity; low hydraulic conductivity; soft wet; abundant clay and dolosilt(?) matrix; common burrows that result in a mottled appearance.

86.7-87.0 No recovery.

87.0-91.0

Quartz sand; yellowish gray 5Y 7/2 and light olive gray 5Y 5/2; black N1 phosphorite and heavy mineral grains; mainly very 

fine to fine quartz sand; minor quartz silt and very fine phosphorite and heavy mineral grains; well sorted; mainly angular to 

subangular and subordinate subrounded; 10-15 percent mainly phosphorite and subordinate heavy mineral grains; trace mica; 

10-15 percent intergrain porosity; low hydraulic conductivity; soft wet; abundant clay and dolosilt(?) matrix; common burrows that result in a mottled appearance.

91.0-93.5

Quartz sand; yellowish gray 5Y 7/2 and minor light olive gray 5Y 5/2; black N1 phosphorite and heavy mineral grains; 

mainly very fine quartz sand; minor quartz silt and fine quartz sand and very fine phosphorite and heavy mineral grains; well 

sorted; mainly angular to subangular and subordinate subrounded; 10-15 percent mainly phosphorite and subordinate heavy 

mineral grains; trace mica; 15-20 percent intergrain porosity; low hydraulic conductivity; soft wet; trace clay matrix.

93.5-100.0

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy mineral grains; mainly very fine quartz sand; minor 

quartz silt and fine quartz sand and very fine phosphorite and heavy mineral grains; well sorted quartz sand; mainly angular to

subangular and subordinate sub rounded; 15 percent mainly phosphorite and subordinate heavy mineral grains; trace mica; 

15 percent intergrain porosity; low hydraulic conductivity; soft wet; minor clay and dolosilt(?) matrix; burrowed; irregular 

laminations.

100.0-102.8

Quartz sand; yellowish gray 5Y 7/2; black N1 phosphorite and heavy mineral grains; mainly very fine quartz sand; minor 

quartz silt and fine quartz sand and very fine phosphorite and heavy mineral grains; well sorted; mainly angular to subangular 

and subordinate subrounded; 15-20 percent mainly phosphorite and subordinate heavy mineral grains; trace mica; 15-20 percent intergrain porosity; low hydraulic conductivity; soft wet; very minor clay and dolosilt(?) matrix; burrowed; irregular 

laminations.

102.8-112.0

Quartz sand; yellowish gray 5Y 7/2 and light olive gray 5Y 5/2; black N1 phosphorite and heavy mineral grains; mainly very 

fine quartz sand; minor quartz silt and very fine phosphorite and heavy mineral grains; well sorted; angular to subangular; 

15-20 percent mainly phosphorite and subordinate heavy mineral grains; trace mica; 15 percent intergrain porosity; low 

hydraulic conductivity; soft wet; minor clay and dolosilt(?) matrix; burrowed; minor irregular laminations of quartz sand with 

abundant clay and dolosilt(?) matrix.

112.0-120.0

Quartz sand; light olive gray 5Y 5/2 and olive gray 5Y 3/2; black N1 phosphorite and heavy mineral grains; mainly very fine 

quartz sand; minor quartz silt and fine quartz sand and very fine phosphorite and heavy mineral grains; well sorted; mainly 

angular to subangular and subordinate subrounded; 15 percent mainly phosphorite and subordinate heavy mineral grains; 

trace mica; 15 percent intergrain porosity; low hydraulic conductivity; soft wet; abundant clay and dolosilt(?) matrix; burrowed; minor irregular laminations of sandy clay.

120.0-121.0

Diatomaceous mudstone; light olive gray 5Y 5/2; black N1 phosphorite and heavy mineral grains; mainly clay-sized; very 

fine phosphorite and heavy mineral grains; diatoms, siliceous spicules and small foraminifers, 15 percent mainly phosphorite 

and subordinate heavy mineral grains; 5 percent microporosity; low hydraulic conductivity; firm when wet.

121.0-124.0

Interlaminated sandy terrigenous mudstone and quartz sand; light olive gray 5Y 5/2 and olive gray 5Y 3/2; black N1 

phosphorite and heavy mineral grains; mainly clay and very fine quartz sand; minor very fine phosphorite and heavy mineral 

grains; well sorted; angular to subangular; diatoms, siliceous spicules, undifferentiated small foraminifers, small benthic 

foraminifers; 10-20 percent mainly phosphorite and subordinate heavy mineral grains; 15 percent intergrain porosity in sand 

laminations; 5 percent microporosity in clay laminations; very low to low hydraulic conductivity; firm wet; burrowed.

124.0-127.7

Interlaminated sandy terrigenous mudstone and quartz sand; light olive gray 5Y 5/2 and olive gray 5Y 3/2; black N1 

phosphorite and heavy mineral grains; mainly clay and very fine quartz sand; minor very fine phosphorite and heavy mineral 

grains; well sorted; angular to subangular; diatoms, siliceous spicules, undifferentiated small foraminifers(?); 10-20 percent 

mainly phosphorite and subordinate heavy mineral grains; 15 percent intergrain porosity in sand laminations; 5 percent 

microporosity in clay laminations; very low to low hydraulic conductivity; firm wet; burrowed; Planolites trace fossil at 

126.7 feet.

Depth

(feet below 

land surface)

Lithologic description of GL-325 test corehole
48 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

127.7-128.3

Quartz conglomerate; light olive gray 5Y 6/1black N1 to dark gray N3 phosphorite and black N1 heavy mineral grains; 

mainly very fine sand- to large pebble-sized quartz grains; minor very fine sand sized to medium pebble sized phosphorite 

grains and very fine heavy mineral grains; poorly sorted; angular to subangular very fine to fine quartz grains and subangular 

to subrounded medium sand- to pebble-sized quartz grains; 10-25 percent mainly phosphorite and subordinate heavy mineral 

grains; 15 percent intergrain porosity; low hydraulic conductivity; soft wet; poorly consolidated; quartz pebbles up to 2.5 cm 

wide; minor clay matrix.

128.3-130.0

Dolosilt; yellowish gray 5Y 7/2; black N1 phosphorite and heavy mineral grains; mainly silt-sized dolomite; minor very fine 

quartz sand and subordinate fine quartz sand, and very fine phosphorite and heavy mineral grains; well sorted; mainly angular 

to subangular and subordinate subrounded; minor quartz sand; 10-15 percent mainly phosphorite and subordinate heavy 

mineral grains; 5 percent microporosity; low hydraulic conductivity.

130-131

Quartz sand with dolosilt matrix; yellowish gray 5Y 7/2; black N1 phosphorite and heavy mineral grains; mainly silt-sized 

dolomite; minor very fine quartz sand and subordinate fine quartz sand, and very fine phosphorite and heavy mineral grains; 

well sorted; mainly angular to subangular and subordinate subrounded; 10-80 percent quartz sand; 10-15 percent mainly 

phosphorite and subordinate heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity.

131.0-134.5

Sandy dolosilt and quartz sand with dolosilt matrix; yellowish gray 5Y 7/2; black N1 phosphorite and heavy mineral grains; 

mainly silt-sized dolomite and very fine to fine quartz sand; minor medium to very coarse quartz sand, very fine to coarse 

phosphorite grains and very fine heavy mineral grains; moderately sorted; mainly angular to subangular and subordinate 

subrounded; 10 percent mainly phosphorite and subordinate heavy mineral grains; 5 percent microporosity; very low 

hydraulic conductivity; medium to very coarse quartz grains floating in dolosilt and finer quartz sand matrix.

134.5-135.5

Dolosilt; yellowish gray 5Y 7/2; black N1 phosphorite and heavy mineral grains; mainly silt-sized dolomite and very fine 

quartz sand; minor fine quartz sand, very fine phosphorite grains and heavy mineral grains; fine sand-sized to small pebblesized fossils; well sorted; mainly angular to subangular and subordinate subrounded; 20-30 percent quartz sand; 10 percent 

mainly phosphorite and subordinate heavy mineral grains; 10 percent undifferentiated fossil fragments; 5 percent microporosity;

very low hydraulic conductivity.

135.5-136.7

Sandy dolosilt and lime mudstone; yellowish gray 5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly silt-sized 

dolomite and very fine quartz sand; minor fine quartz sand, very fine phosphorite and heavy mineral grains; fine sand-sized to 

small pebble-sized fossils; well sorted; mainly angular to subangular and subordinate subrounded; 20-40 percent quartz sand; 

10 percent mainly phosphorite and subordinate heavy mineral grains; 5 percent pelecypods and undifferentiated fossil fragments; 5 percent microporosity; very low hydraulic conductivity.

136.7-140.5 No recovery

140.5-145.0

Pelecypod lime floatstone with sandy pelecypod lime wackestone and mud-dominated lime packstone matrix; yellowish gray 

5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly medium sand-sized to small pebble-sized fossils, clay-sized 

micrite and very fine quartz sand; minor fine quartz sand, and very fine phosphorite and heavy mineral grains; well sorted; 

mainly angular to subangular and subordinate subrounded; pelecypods and gastropods; 20-45 percent quartz sand; 5-10 percent mainly phosphorite and subordinate heavy mineral grains; 15 percent moldic porosity; low hydraulic conductivity.

145.0-150.5

Pelecypod lime rudstone with sandy pelecypod mud-dominated and grain-dominated packstone matrix; yellowish gray 

5Y 8/1 and white N9; black N1 phosphorite and heavy mineral grains; mainly medium sand-sized to large pebble-sized 

fossils, clay-sized micrite and very fine quartz sand; minor fine quartz sand, and very fine phosphorite and heavy mineral 

grains; well sorted; mainly angular to subangular and subordinate subrounded; pelecypods and gastropods; 20-45 percent 

quartz sand; 5-10 percent mainly phosphorite and subordinate heavy mineral grains; 25 percent moldic porosity; moderate 

hydraulic conductivity.

150.5-151.1

Lime mudstone; pale olive 5Y 6/2; black N1 phosphorite and heavy mineral grains; mainly clay-sized micrite; minor very 

fine to fine quartz sand and very fine phosphorite and heavy mineral grains; well sorted; mainly angular to subangular and 

subordinate subrounded; trace pelecypods; minor quartz sand; trace mainly phosphorite and subordinate heavy mineral 

grains; 5 percent microporosity; very low hydraulic conductivity; percentage of quartz increase upwards.

151.1-154.5

Interlaminated sandy dolosilt and quartz sand with dolosilt matrix; pale olive 5Y 6/2; black N1 phosphorite and heavy mineral grains; mainly clay-sized micrite and very fine quartz sand; minor fine quartz sand, fine sand- to pebble-sized fossils, and 

very fine phosphorite and heavy mineral grains; well sorted; mainly angular to subangular and subordinate subrounded; 10-30 

percent undifferentiated fossils and pelecypods; 20-70 percent quartz sand; trace mainly phosphorite and subordinate heavy 

mineral grains; 5 percent microporosity; very low hydraulic conductivity; thinly laminated; borrows parallel to horizontal 

laminations.

Depth

(feet below 

land surface)

Lithologic description of GL-325 test corehole
Appendix--Litholotic Descriptions, Core GL-325 49

154.5-157.9

Quartz sandstone with abundant micrite matrix; light greenish gray 5GY 8/1; black N1 phosphorite and heavy mineral grains; 

mainly clay-sized micrite and very fine quartz sand; minor fine quartz sand and very fine phosphorite and heavy mineral 

grains; well sorted; mainly angular to subangular and subordinate subrounded; 20-30 percent undifferentiated fossils and 

trace echinoid spines; 5 percent mainly phosphorite and subordinate heavy mineral grains; 5 percent microporosity; very low 

hydraulic conductivity; abundant micrite matrix.

157.9-159.0

Quartz sandstone with abundant micrite matrix; light greenish gray 5GY 8/1; black N1 phosphorite and heavy mineral grains; 

mainly clay-sized micrite and very fine quartz sand; minor fine to coarse quartz sand, fine sand- to medium pebble-sized 

fossils, very fine to coarse phosphorite and very fine heavy mineral grains; moderately sorted; mainly angular to subangular 

and subordinate subrounded; 10-20 percent undifferentiated fossils and pelecypods; 5 percent mainly phosphorite and subordinate heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; abundant micrite matrix.

159.0-160.5 No recovery.

160.5-161.1

Quartz sandstone with abundant micrite matrix; light greenish gray 5GY 8/1; black N1 phosphorite and heavy mineral grains; 

mainly clay-sized micrite and very fine quartz sand; minor fine to coarse quartz sand, fine sand- to medium pebble-sized fossils, very fine to coarse phosphorite and very fine heavy mineral grains; moderately sorted; mainly angular to subangular and 

subordinate subrounded; 10-20 percent undifferentiated fossils and pelecypods; 5 percent mainly phosphorite and subordinate 

heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; abundant micrite matrix.

161.1-164.2

Pelecypod lime rudstone with sandy lime mudstone and quartz sandstone matrix; yellowish gray 5Y 8/1 and light greenish 

gray 5GY 8/1; black N1 phosphorite and heavy mineral grains; mainly clay-sized micrite, fine quartz sand and fine sand- to 

large pebble-sized fossils; minor very fine and medium to coarse quartz sand, very fine to fine phosphorite and heavy mineral 

grains; moderately sorted; mainly angular to subangular and subordinate subrounded; pelecypods and trace bryozoans; 5 percent mainly phosphorite and subordinate heavy mineral grains; 10 percent intergrain porosity; low hydraulic conductivity; 

quartz sandstone has abundant micrite matrix; large pebble-sized bryozoans in the upper 3 inches of interval.

164.2-166.0

Pelecypod lime rudstone with quartz sand matrix; yellowish gray 5Y 8/1 and light greenish gray 5GY 8/1; black N1 phosphorite and heavy mineral grains; mainly clay-sized micrite, fine quartz sand and fine sand- to large pebble-sized fossils; minor 

very fine and medium to coarse quartz sand, very fine to medium phosphorite and heavy mineral grains; well sorted; mainly 

angular to subangular and subordinate subrounded; pelecypods and undifferentiated fossils; 5 percent mainly phosphorite and 

subordinate heavy mineral grains; 10 percent intergrain porosity; low hydraulic conductivity.

166.0-169.1

Interbedded pelecypod-rich quartz sand and pelecypod rudstone with quartz sand matrix; pale olive 10Y 6/2; black N1 phosphorite and heavy mineral grains; mainly clay-sized micrite, fine quartz sand, fine sand- to large pebble-sized fossils; minor 

very fine and medium to coarse quartz sand, and very fine phosphorite and heavy mineral grains; well sorted; mainly angular 

to subangular and subordinate subrounded; pelecypods and trace barnacles and echinoid spines; 10-15 percent mainly phosphorite and subordinate heavy mineral grains; 20-25 percent intergrain porosity; low hydraulic conductivity.

169.1-170.5 No recovery.

170.5-174.2

Interbedded pelecypod-rich quartz sand and pelecypod rudstone with quartz sand matrix; pale olive 10Y 6/2; black N1 phosphorite and heavy mineral grains; mainly clay-sized micrite, fine quartz sand, fine sand- to large pebble-sized fossils; minor 

very fine and medium to coarse quartz sand, and very fine phosphorite and heavy mineral grains; well sorted; mainly angular 

to subangular and subordinate subrounded; pelecypods and trace barnacles and echinoid spines; 10-15 percent mainly phosphorite and subordinate heavy mineral grains; 20-25 percent intergrain porosity; low hydraulic conductivity.

174.2-175.5

Quartz sand; light olive gray 5Y 6/1; black N1 phosphorite and heavy mineral grains; mainly fine quartz sand; minor very 

fine and medium quartz sand, and very fine to fine phosphorite and heavy mineral grains; well sorted; mainly angular to 

subangular and subordinate subrounded; 20 percent undifferentiated fossils and pelecypods; 15 percent mainly phosphorite 

and subordinate heavy mineral grains; 25 percent intergrain porosity; low hydraulic conductivity.

175.5-180.5 No recovery

180.5-183.2

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly very fine quartz sand; minor fine 

quartz sand, fine sand- to small pebble-sized fossils, and very fine phosphorite and heavy mineral grains; well sorted; mainly 

angular to subangular and subordinate subrounded; undifferentiated fossils and pelecypods; 10 percent mainly phosphorite 

and subordinate heavy mineral grains; 20 percent intergrain porosity; low hydraulic conductivity; minor clay matrix.

Depth

(feet below 

land surface)

Lithologic description of GL-325 test corehole
50 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

183.2-185.0

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphorite and heavy mineral grains; mainly very fine quartz sand; minor fine 

quartz sand, fine sand- to small pebble-sized fossils, and very fine phosphorite and heavy mineral grains; well sorted; mainly 

angular to subangular and subordinate subrounded; <5 percent undifferentiated fossils and pelecypods; 10 percent mainly 

phosphorite and subordinate heavy mineral grains; 15 percent intergrain porosity; low hydraulic conductivity; minor clay 

matrix.

185.0-189.1

Sandy terrigenous mudstone; light olive gray 5Y 6/1; black N1 phosphorite and heavy mineral grains; mainly clay and very 

fine quartz sand; minor fine quartz sand and very fine phosphorite and heavy mineral grains; well sorted; mainly angular to 

subangular; 20-60 percent quartz sand; minor small benthic foraminifers; 15 percent mainly phosphorite and subordinate 

heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; burrowed in part; thin horizontal laminations.

189.1-190.5 No recovery.

190.5-194.2

Sandy terrigenous mudstone; light olive gray 5Y 6/1; black N1 phosphorite and heavy mineral grains; mainly clay and very 

fine quartz sand; minor fine and coarse quartz sand and very fine phosphorite and heavy mineral grains; moderately sorted; 

mainly angular to subangular; 20-60 percent quartz sand; minor small benthic foraminifers; 15 percent mainly phosphorite 

and subordinate heavy mineral grains; 5 percent microporosity; very low hydraulic conductivity; burrowed in part; thin horizontal laminations; more species diversity in benthic foraminifers than interval 185 to 189.1 feet.

194.2-194.3

Sandy dolosilt; light greenish gray 5GY 8/1; black N1 phosphorite and heavy mineral grains; mainly silt-sized dolomite and 

very fine quartz sand; minor fine and coarse quartz sand and very fine to coarse phosphorite grains and very fine heavy mineral grains; moderately sorted; mainly angular to subangular; 15 percent mainly phosphorite and subordinate heavy mineral 

grains; 5 percent microporosity; very low hydraulic conductivity; burrowed in part; thin horizontal laminations.

194.3-200.5 No recovery.

Depth

(feet below 

land surface)

Lithologic description of GL-325 test corehole
Appendix--Litholotic Description, Core GL-326 51

GL-326 Test Corehole

Florida Geological Survey well number W-18073

GWSI number GL-326

Total depth 39.5 feet

Cored from 0 to 39.5 feet

County Glades

Location SW, SW, sec. 30, T42S, R32E

Latitude 26° 46′ 59′′

Longitude 81° 10′ 17′′

Elevation 16 feet

Completion date July 24, 1999

Other types of logs available Induction, gamma ray, resistivity, spontaneous potential

Owner U.S. Geological Survey

Driller Florida Geological Survey

Core described by Kevin J. Cunningham

Fill 0 to 7.0 feet

Undifferentiated 7.0 to 9.3 feet

Caloosahatchee Formation 9.3 to 17.75 feet

Top Tamiami Formation 17.75 feet

Water-table aquifer 0 to 33.3 feet

Top Tamiami confining zone 33.3 feet (electrical logs contributed to selection of tops)
52 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

Depth

(feet below 

land surface)

Lithologic description of GL-326 test corehole

0.0-7.0 Fill; very pale orange 10YR 8/2, pale yellowish brown 10YR 6/2.

7.0 -8.0

Fill with a clast of Helisoma lime rudstone with quartz sand-rich wackestone matrix; light gray N7; possible top Fort Thompson at 7 feet based on clast of Helisoma-Fort Thompson lithology, color change to light gray, and comparison to depth of base 

of fill along Caloosahatchee River bank; poor sample quality.

8.0-9.0 No recovery.

9.0-9.3

Quartz sand; dark gray N3 to medium light gray N6, 10 YR 2/2 humus; mainly fine to medium quartz sand; minor clay, very 

fine and medium quartz and clay to very fine humus; well sorted; subangular to subrounded; local abundant clay; up to 5 percent humus; 25 percent intergrain porosity; low to moderate hydraulic conductivity; soft to friable wet; loose unconsolidated 

sand to semiconsolidated clay-rich sand and very thinly laminated clay (2-mm thick).

9.3-9.5

Rubble of pelecypod lime rudstone with quartz sand-rich grain dominated packstone matrix; very pale orange 10YR 8/2; 

mainly medium quartz sand; minor very fine to fine and coarse quartz sand, and fine sand-sized to medium pebble-sized 

fossils and fossil fragments; well sorted; subangular to subrounded; 25 percent quartz sand; 15 percent intergrain porosity; 

low to moderate hydraulic conductivity; sample is rubble.

9.5-10.9

Pelecypod lime floatstone with quartz sand-rich, skeletal wackestone matrix; very pale orange 10YR 8/2; mainly very fine to 

medium quartz sand; minor coarse quartz sand and fine sand-sized to very large pebble-sized fossils and fossil fragments; 

well sorted; subangular to subrounded; pelecypods and bryozoans; 20-30 percent quartz sand; 15 percent moldic, root-mold, 

intergrain porosity; low to moderate hydraulic conductivity; very hard wet; well consolidated; 1-mm diameter, semivertical 

root molds.

10.9-14.0 No recovery.

14.0-14.5 Rubble of limestone and pelecypod shells.

14.5-17.0 No recovery.

17.0-17.8

Pelecypod lime rudstone with quartz sand-rich marly matrix and loose oyster fragments; yellowish gray 5Y 8/1, medium light 

gray N6 to very light gray N8; very fine sand-sized to very large pebble-sized fossils and fossil fragments, clay-size marl; 

minor very fine quartz sand; moderately sorted; subangular to subrounded; pelecypods and subordinate oysters and bryozoans; 10 percent quartz sand; 5-25 percent intergrain porosity; low to moderate hydraulic conductivity; soft wet; marl matrix.

17.8-25.0 No recovery.

25.0-27.5

Loose pelecypod shells; very pale orange 10YR 8/2, medium dark gray N4 to very light gray N6; coarse sand-sized to 

medium pebble-sized fossils and fossil fragments; minor very fine to medium quartz sand; well sorted; subangular to 

subrounded; 95 percent pelecypods and subordinate gastropods; 5 percent quartz sand; trace marl; 25-35 percent intergrain 

porosity; moderate to high hydraulic conductivity; unconsolidated, loose shells; most shells broken; trace matrix of sandy 

marl.

27.5-28.0

Quartz sand; light gray N7 to very light gray N8; N1 heavy minerals; mainly fine to medium quartz sand; minor very fine and 

coarse quartz; well sorted; subangular to subrounded; 5 percent pelecypod shells; trace heavy minerals; 25 percent intergrain 

porosity; moderate hydraulic conductivity; soft wet; unconsolidated.

28.0-29.5 No recovery.

29.5-31.0

Loose pelecypod shells with quartz sand and clay matrix; yellowish gray 5Y 7/2, very pale orange 10YR 8/2, medium dark 

gray N4 to very light gray N6; medium sand-sized to small pebble-sized fossils and fossil fragments; minor very fine to 

medium quartz sand; well sorted; subangular to subrounded; 80 percent pelecypods and subordinate gastropods; 10 percent 

quartz sand; 10 percent clay; 20 percent intergrain porosity; low hydraulic conductivity; soft wet; unconsolidated.

31.0-31.5

Loose pelecypod shells; very pale orange 10YR 8/2, medium dark gray N4 to very light gray N6; coarse sand-sized to 

medium pebble-sized fossils and fossil fragments; minor very fine to medium quartz sand; well sorted; subangular to 

subrounded; 95 percent pelecypods and subordinate gastropods; 5 percent quartz sand; trace marl; 25-35 percent intergrain 

porosity; moderate to high hydraulic conductivity; unconsolidated, loose shells; most shells broken; trace matrix of sandy 

marl.
Appendix--Litholotic Description, Core GL-326 53

31.5-33.3

Quartz sand; very light gray N8, yellowish gray 5Y 8/1; N1 phosphate grains and heavy minerals; mainly fine to medium 

quartz sand; minor very fine and coarse quartz; well sorted; subangular to subrounded; 5 percent pelecypod shells; trace 

heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; unconsolidated.

33.3-33.5

Quartz sand; light olive gray 5Y 6/1; N1 phosphate grains and heavy minerals; mainly fine to medium quartz sand; minor 

very fine and coarse quartz, and medium sand-sized to medium pebble-sized pelecypod shells; well sorted; subangular to 

subrounded; 20 percent pelecypod shells; 10 percent clay matrix; trace heavy minerals; 15 percent intergrain porosity; low 

hydraulic conductivity; soft wet; unconsolidated.

33.5-34.5 No recovery.

34.5-37.0

Mixture of pelecypod shells, quartz sand and clay; sediments is light olive gray; shells are very pale orange 10YR 8/2, 

medium dark gray N4 to very light gray N6; coarse sand-sized to medium pebble-sized fossils and fossil fragments, and very 

fine to medium quartz sand; minor coarse quartz sand; well sorted; subangular to subrounded; 60 percent pelecypods and 

subordinate gastropods; 35 percent quartz sand; 5 percent clay; 10 percent intergrain porosity; low hydraulic conductivity; 

soft wet; unconsolidated, loose shells; most shells broken; trace matrix of sandy marl.

37.0-38.5

Clay with abundant pelecypod shells and minor quartz sand; light olive gray 5Y 5/2; olive gray 5Y 4/1; granule to small 

pebble-sized shells; minor very fine to fine quartz sand and medium to very large pebble-sized shells; well sorted; subangular 

to subrounded; 35 percent pelecypod shells and subordinate gastropods; 5 percent quartz sand; 5 percent intergrain porosity; 

very low hydraulic conductivity; firm wet; semiconsolidated; gradational with unit above.

38.5-39.5 No recovery.

Depth

(feet below 

land surface)

Lithologic description of GL-326 test corehole
54 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

GL-327 Test Corehole

FGS well number W-18074

GWSI number GL-327

Total depth 454 feet

Cored from 0 to 454 feet

County Glades

Location SW, sec. 22, T42S, R32E

Latitude 26° 48′ 2.7′′

Longitude 81° 07′ 5.2′′

Elevation 14 feet

Completion Date April 13, 2000 

Other types of logs available Resistivity, gamma ray, spontaneous potential

Owner USGS

Driller FGS 

Core described by Kevin J. Cunningham 

Fill 0 to 19.8(?) feet 

Undifferentiated 19.8(?) to 33 feet

Tamiami Formation 33 to 141 feet

Upper Peace River Formation 141 to 446.5 feet

Lower Peace River Formation(?) 446.5 to 454 feet (based on gamma-ray log)

Water-table aquifer 0 to 28.9 feet 

Tamiami confining zone 28.9 to 39 feet

Lower Tamiami aquifer 39 to 98.8 feet 
Appendix--Litholotic Description, Core GL-327 55

Depth

(feet below 

land surface)

Lithologic description of GL-327 test corehole

0.0-8.8 Fill

 8.8-10.0 No recovery

10.0-19.3 Fill(?)

19.3-19.8

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand; minor medium to coarse quartz sand; moderate to 

well sorted quartz sand; 25 percent intergrain porosity; moderate hydraulic conductivity; friable; 10-30 percent broken 

pelecypod shells 

19.8-20.3 Quartz sand; dark gray N3; mainly very fine to fine quartz sand; minor medium quartz sand; well sorted quartz sand; 

25 percent intergrain porosity; low hydraulic conductivity; moderately friable; abundant dark organic material in matrix 

20.3-23.0 No recovery

23.0-23.2 Quartz sand; dark gray N3; mainly very fine to fine quartz sand; minor medium quartz sand; well sorted quartz sand; 

25 percent intergrain porosity; low hydraulic conductivity; moderately friable; abundant dark organic material in matrix

23.2-24.0 No recovery

24.0-25.5 Quartz sand; pale yellowish brown 10YR 6/2 to white N9; mainly very fine to fine quartz sand; minor medium to very 

coarse quartz sand; well sorted quartz sand; 25 percent intergrain porosity; moderate hydraulic conductivity; friable

25.5-28.0 No recovery

28.0-28.9 Quartz sand; pale yellowish brown 1OYR 6/2 to white N9; mainly very fine to fine quartz sand; minor medium to very 

coarse quartz sand; well sorted quartz sand; 25 percent intergrain porosity; moderate hydraulic conductivity; friable

28.9-31.2

Quartz sand with abundant pelecypods; yellowish gray 5Y 8/1; mainly fine quartz sand; minor very fine and medium quartz 

sand; pelecypods up to large pebble size; well sorted quartz sand; poorly sorted quartz sand and shells; 25 percent intergrain 

porosity; low hydraulic conductivity; 40-50 percent pelecypod shells; clay matrix

31.2-33.0 No recovery

33.0-34.5

Quartz sand with lime mudstone matrix; brownish black 5YR 2/1 to grayish black N2; mainly fine quartz sand; minor very 

fine and medium quartz sand; well sorted quartz sand; very poorly sorted quartz sand and shells; low hydraulic conductivity; 

20-40 percent gastropods (Helisoma); fresh-water environment

34.5-35.4 Quartz sand; pale yellowish brown 1OYR 6/2; mainly fine quartz sand; minor very fine and medium to coarse quartz sand; 

pelecypods up to large pebble size; moderate to well sorted quartz sand; moderate hydraulic conductivity; friable

35.4-35.8

Quartz sand with abundant pelecypods; yellowish gray 5Y 8/1; mainly fine quartz sand; minor very fine and medium to 

coarse quartz sand; pelecypods up to large pebble size; moderate to well sorted quartz sand; low hydraulic conductivity; 

friable; 40-50 percent pelecypod shells; marl matrix

35.8-37.0 No recovery

37.0-37.8 Fill

37.8-39.0

Quartz sand with abundant pelecypods; yellowish gray 5Y 8/1; mainly fine-medium quartz sand; minor very fine and coarse 

quartz sand; pelecypods up to large pebble size; moderate to well sorted quartz sand; low hydraulic conductivity; friable; 

40-50 percent pelecypod shells (including Chione); marl matrix

39.0-41.0

Gastropod and pelecypod lime rudstone and floatstone with matrix of quartz-sand-rich lime wackestone and mud-dominated 

lime packstone or quartz sand with lime mudstone matrix; medium dark gray N4 to medium light gray N6; mainly very fine 

to fine quartz sand; coarse sand to very large pebble-sized fossils; well sorted quartz sand; 20-40 percent moldic and vuggy 

porosity; high hydraulic conductivity; hard; fossils mainly low-spiraled gastropods and minor pelecypods

41.0-45.0 No recovery
56 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

45.0-46.8

Pelecypod lime rudstone and floatstone with matrix of quartz-sand-rich lime wackestone and mud-dominated lime packstone or quartz sand with lime mudstone matrix; medium dark gray N4 to light gray N7; mainly very fine to fine quartz sand; 

coarse sand to very large pebble-sized fossils; well sorted quartz sand; 20-40 percent moldic and vuggy porosity; high 

hydraulic conductivity; hard; fossils mainly pelecypods (including Chione) and minor gastropods

46.8-51.0 No recovery

51.0-51.4 Rubble of lithology from interval between 45 and 46.8 feet.

51.4-61.0 No recovery

61.0-61.5

Unconsolidated pelecypod lime rudstone and quartz sand matrix; medium dark gray N4 to medium light gray N6; mainly 

medium to coarse quartz sand and minor very fine and very coarse quartz sand; mainly coarse to granule-sized fossils; 

moderate to well sorted quartz sand; sand and shells poorly sorted; 25 percent intergrain porosity; moderate hydraulic 

conductivity; friable; fossils mainly broken pelecypods; 30 percent quartz sand

61.5-66.0 No recovery

66.0-68.4

Unconsolidated pelecypod lime rudstone and quartz sand matrix; medium dark gray N4 to medium light gray N6; mainly 

medium to coarse quartz sand and minor very fine and very coarse quartz sand; mainly coarse to small pebble-sized fossils; 

moderate to well sorted quartz sand; sand and shells poorly sorted; 25 percent intergrain porosity; moderate hydraulic 

conductivity; friable; fossils mainly broken pelecypods; 30 percent quartz sand

68.4-69.3

Quartz sand with abundant pelecypods; medium dark gray N4 to medium light gray N6; mainly medium quartz sand and 

minor fine and coarse quartz sand; mainly coarse to small pebble-sized fossils; well sorted quartz sand; sand and shells 

poorly sorted; 25 percent intergrain porosity; moderate hydraulic conductivity; friable; 30 percent broken pelecypod shells

69.3-71.0 No recovery

71.0-71.2

Quartz sand with abundant pelecypods; medium dark gray N4 to medium light gray N6; mainly medium quartz sand and 

minor fine and coarse quartz sand; mainly coarse to small pebble-sized fossils; well sorted quartz sand; sand and shells 

poorly sorted; 25 percent intergrain porosity; moderate hydraulic conductivity; friable; 30 percent broken pelecypod shells

71.2-76.0 No recovery (driller “felt” soft sand drilling through interval)

76.0-80.0

Quartz sand with abundant pelecypods; yellowish gray 5Y 8/1 and medium gray N5 to light gray N7; mainly medium quartz 

sand and minor fume and coarse quartz sand; mainly coarse to granule-sized fossils; well sorted quartz sand; sand and shells 

poorly sorted; 30 percent intergrain porosity; moderate hydraulic conductivity; friable; 40-60 percent broken pelecypod 

shells

80.0-81.0 No recovery

81.0-84.9

Quartz sand with abundant pelecypods; yellowish gray 5Y 8/1 and medium gray N5 to light gray N7; mainly medium quartz 

sand and minor fume and coarse quartz sand; mainly coarse to small-pebble sized fossils; well sorted quartz sand; sand and 

shells poorly sorted; 30 percent intergrain porosity; moderate hydraulic conductivity; friable; 40-60 percent broken pelecypod shells

84.9-86.0 No recovery

86.0-89.9

Quartz sand with abundant pelecypods; yellowish gray 5Y 8/1 and medium gray N5 to light gray N7; mainly medium quartz 

sand and minor fine and coarse quartz sand; mainly coarse to small-pebble sized fossils; well sorted quartz sand; sand and 

shells poorly sorted; 30 percent intergrain porosity; moderate hydraulic conductivity; friable; 40-60 percent broken pelecypod shells

89.9-91.0 No recovery

91.0-94.0

Quartz sand with abundant pelecypods; yellowish gray 5Y 8/1 and medium gray N5 to light gray N7; mainly medium quartz 

sand and minor fine and coarse quartz sand; mainly coarse to small-pebble sized fossils; well sorted quartz sand; sand and 

shells poorly sorted; 30 percent intergrain porosity; moderate hydraulic conductivity; friable; 40-60 percent broken pelecypod shells

Depth

(feet below 

land surface)

Lithologic description of GL-327 test corehole
Appendix--Litholotic Description, Core GL-327 57

94.0-95.4

Quartz sand with abundant pelecypods; yellowish gray 5Y 8/1 and medium gray N5 to light gray N7; mainly medium quartz 

sand and minor fume and coarse quartz sand; mainly coarse to small pebble sized fossils; well sorted quartz sand; sand and 

shells poorly sorted; 30 percent intergrain porosity; moderate hydraulic conductivity; friable; 40-60 percent broken pelecypod shells, bryozoans and barnacles

95.4-96.0 No recovery

96.0-98.8

Unconsolidated pelecypod lime rudstone with matrix of quartz sand with minor clay matrix; yellowish gray 5Y 8/1 and 

medium gray N5 to light gray N7; mainly medium quartz sand and minor fine and coarse quartz sand; mainly medium to 

large-pebble sized fossils; sand and shells very poorly sorted; 20 percent intergrain porosity; low to moderate hydraulic 

conductivity; 60-80 percent broken pelecypod shells, gastropods and barnacles

98.8-99.1 Sandy, silty, gastropod-rich terrigenous mudstone; brownish gray 5Y 4/1 to brownish black 5YR 2/1; mainly very fine to 

medium quartz sand; mainly medium to granule-sized fossils; very low hydraulic conductivity; firm

99.1-99.6 Pelecypod-rich terrigenous mudstone; pale yellowish brown 1OYR 6/2; very low hydraulic conductivity; firm; 50 percent

pelecypods

 99.6-100.9 Pelecypod-rich, silty terrigenous mudstone; brownish gray 5YR 4/1; granule to medium pebble-sized fossils; very low 

hydraulic conductivity; firm; minor pelecypods

100.9-101.0 No recovery

101.0-104.3 Pelecypod-rich, silty terrigenous mudstone; brownish gray 5YR 4/1 to light brownish gray 5YR 6/1; medium sand to 

granule-sized fossils; very low hydraulic conductivity; firm; minor fragments of thin-shelled pelecypods

104.3-106.0 No recovery

106.0-110.3 Pelecypod-rich, silty terrigenous mudstone; brownish gray 5YR 4/1 to light brownish gray 5YR 6/1; medium sand to 

granule-sized fossils; very low hydraulic conductivity; firm; minor fragments of thin-shelled pelecypods

110.3-111.0 No recovery

111.0-123.0 Silty terrigenous mudstone; light brownish gray 5YR 6/1; very low hydraulic conductivity; firm; trace diatoms

123.0-127.0 Silty terrigenous mudstone; light brownish gray 5YR 6/1; very low hydraulic conductivity; firm; minor siliceous spicules; 

trace benthic foraminifera

127.0-132.0 Silty quartz sand; yellowish gray 5Y 8/1; low hydraulic conductivity; calcareous terrigenous mudstone matrix

132.0-139.0

Quartz sand; yellowish gray 5Y 8/1; mainly fine to medium quartz sand and minor very fine and coarse to very coarse quartz 

sand; well sorted quartz sand; low hydraulic conductivity; 10-20 percent broken fossil fragments; minor marl matrix; intraclasts of sandstone

139.0-140.0

Quartz sand; yellowish gray 5Y 8/1; mainly medium quartz sand and minor fine and coarse to very coarse quartz sand; well 

sorted quartz sand; low hydraulic conductivity; 10-20 percent broken fossil fragments; very minor marl matrix; intraclasts of 

sandstone

140.0-141.0 No recovery

141.0-141.2

Rubble of quartz sandstone; medium dark gray N4 to medium gray N5; mainly very fine to fine quartz sand and minor 

medium quartz sand; well sorted quartz sand; mainly vuggy porosity; moderate hydraulic conductivity; calcite cemented; 

vuggy porosity may be associated with a possible unconformity at 141 feet

141.2-141.5 Quartz sandstone; yellowish gray 5Y 8/1; mainly medium quartz sand and minor fine and coarse to very coarse quartz sand; 

moderately sorted quartz sand; mainly vuggy porosity; moderate hydraulic conductivity; hard

141.5-146.0 No recovery

146.0-146.2 Rubble

146.2-151.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-327 test corehole
58 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

151.0-155.0

Quartz sand; yellowish gray 5Y 8/1; mainly medium to coarse quartz sand and minor fine and very coarse quartz sand; 

moderately sorted quartz sand; 1-2 percent phosphorite and heavy minerals; trace mica; 25 percent intergrain porosity; low 

to moderate hydraulic conductivity; minor clay matrix

155.0-156.0 No recovery

156.0-160.1

Quartz sand; yellowish gray 5Y 8/1; mainly medium to coarse quartz sand and minor fine and very coarse quartz sand; 

moderately sorted quartz sand; 1-2 percent phosphorite and heavy minerals; trace mica; 25 percent intergrain porosity; low 

to moderate hydraulic conductivity; minor clay matrix

160.1-161.0 No recovery

161.0-165.3

Quartz sand; yellowish gray 5Y 8/1; mainly medium to coarse quartz sand and minor fine and very coarse quartz sand; 

moderately sorted quartz sand; 1-2 percent phosphorite and heavy minerals; trace mica; 25 percent intergrain porosity; low 

to moderate hydraulic conductivity; minor clay matrix

165.3-166.0 No recovery

166.0-167.0

Quartz sand; yellowish gray 5Y 8/1; mainly medium to coarse quartz sand and minor fine and very coarse quartz sand; 

moderately sorted quartz sand; 1-2 percent phosphorite and heavy minerals; trace mica; 25 percent intergrain porosity; low 

to moderate hydraulic conductivity; minor clay matrix

167.0-170.5

Quartz sand; yellowish gray 5Y 8/1; mainly fine to medium quartz sand and minor very fine and coarse to very coarse quartz 

sand; moderately sorted quartz sand; 1-2 percent phosphorite and heavy minerals; 25 percent intergrain porosity; low to 

moderate hydraulic conductivity; minor clay matrix

170.5-171.0 No recovery

171.0-173.7

Quartz sand; yellowish gray 5Y 8/1 to very light gray N8; mainly fine quartz sand and minor very fine and medium quartz 

sand; well sorted quartz sand; 2-5 percent phosphorite and heavy minerals; trace mica; 30 percent intergrain porosity; 

moderate hydraulic conductivity; friable; trace clay matrix; bioturbated

173.7-176.0 No recovery

176.0-180.8

Quartz sand; light olive gray 5Y 6/1; mainly very fine to fine quartz sand and minor medium to coarse quartz sand; well 

sorted quartz sand; 5 percent phosphorite and heavy minerals; trace mica; 20-25 percent intergrain porosity; low hydraulic 

conductivity; friable; trace clay matrix; bioturbated

180.8-181.0 No recovery

181.0-190.7

Quartz sand; light olive gray 5Y 6/1; mainly very fine to fine quartz sand and minor medium to coarse quartz sand; well 

sorted quartz sand; 5 percent phosphorite and heavy minerals; trace mica; 20-25 percent intergrain porosity; low hydraulic 

conductivity; friable; trace clay matrix; bioturbated

190.7-191.0 No recovery

191.0-210.7

Quartz sand; light olive gray 5Y 6/1; mainly very fine to fine quartz sand and minor medium quartz sand; well sorted quartz 

sand; 5 percent phosphorite and heavy minerals; trace mica; 20-25 percent intergrain porosity; low hydraulic conductivity; 

friable; trace clay matrix; bioturbated

210.7-211.0 No recovery

211.0-220.4

Quartz sand; light olive gray 5Y 6/1; mainly very fine to fine quartz sand and minor medium quartz sand; well sorted quartz 

sand; 5 percent phosphorite and heavy minerals; trace mica; 20-25 percent intergrain porosity; low hydraulic conductivity; 

friable; trace clay matrix; bioturbated

220.4-221.0 No recovery

221.0-225.7

Quartz sand; light olive gray 5Y 6/1; mainly very fine to fine quartz sand and minor medium quartz sand; well sorted quartz 

sand; 5 percent phosphorite and heavy minerals; trace mica; 20-25 percent intergrain porosity; low hydraulic conductivity; 

friable; trace clay matrix; bioturbated

225.7-226.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-327 test corehole
Appendix--Litholotic Description, Core GL-327 59

226.0-255.6

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand and trace medium quartz sand; well sorted quartz 

sand; 5-10 percent phosphorite and heavy minerals; trace mica; 20 percent intergrain porosity; low hydraulic conductivity; 

friable; trace to minor clay matrix; bioturbated

255.6-256.0 No recovery

256.0-265.5

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand and trace medium quartz sand; well sorted quartz 

sand; 5-10 percent phosphorite and heavy minerals; trace mica; 20 percent intergrain porosity; low hydraulic conductivity; 

friable; trace to minor clay matrix; bioturbated

265.5-266.0 No recovery

266.0-270.8

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand and trace medium quartz sand; well sorted quartz 

sand; 5-10 percent phosphorite and heavy minerals; trace mica; 20 percent intergrain porosity; low hydraulic conductivity; 

friable; trace to minor clay matrix; bioturbated

270.8-271.0 No recovery

271.0-275.7

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand and trace medium quartz sand; well sorted quartz 

sand; 5-10 percent phosphorite and heavy minerals; trace mica; 20 percent intergrain porosity; low hydraulic conductivity; 

friable; trace to minor clay matrix; bioturbated

275.7-276.0 No recovery

276.0-280.1

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand and trace medium quartz sand; well sorted quartz 

sand; 5-10 percent phosphorite and heavy minerals; trace mica; 20 percent intergrain porosity; low hydraulic conductivity; 

friable; trace to minor clay matrix; bioturbated

280.1-290.4

Quartz sand; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations; mainly very fine to fine quartz sand 

and trace medium quartz sand; well sorted quartz sand; 20 percent intergrain porosity; low hydraulic conductivity; friable; 

trace clay matrix; bioturbated; uncommon thick laminations (0.25-1.0 inch thick)

290.4-291.0 No recovery

291.0-300.5

Quartz sand; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations; mainly very fine to fine quartz sand 

and trace medium quartz sand; well sorted quartz sand; 20 percent intergrain porosity; low hydraulic conductivity; friable; 

trace clay matrix; bioturbated; uncommon thick laminations (0.25-1.0 inch thick)

300.5-301.0 No recovery

301.0-305.8

Quartz sand; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations; mainly very fine to fine quartz sand 

and trace medium quartz sand; well sorted quartz sand; 20 percent intergrain porosity; low hydraulic conductivity; friable; 

trace clay matrix; bioturbated; uncommon thick laminations (0.25-1.0 inch thick)

305.8-306.0 No recovery

306.0-310.6

Quartz sand; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations; mainly very fine to fine quartz sand 

and trace medium quartz sand; well sorted quartz sand; 20 percent intergrain porosity; low hydraulic conductivity; friable; 

trace clay matrix; bioturbated; uncommon thick laminations (0.25-1.0 inch thick)

310.6-311.0 No recovery

311.0-315.0

Quartz sand; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations; mainly very fine to fine quartz sand 

and trace medium quartz sand; well sorted quartz sand; 20 percent intergrain porosity; low hydraulic conductivity; friable; 

trace clay matrix; bioturbated; uncommon thick laminations (0.25-1.0 inch thick)

315.0-316.0 No recovery

316.0-317.8

Quartz sand; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations; mainly very fine to fine quartz sand 

and trace medium quartz sand; well sorted quartz sand; 20 percent intergrain porosity; low hydraulic conductivity; friable; 

trace clay matrix; bioturbated; uncommon thick laminations (0.25-1.0 inch thick)

Depth

(feet below 

land surface)

Lithologic description of GL-327 test corehole
60 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

317.8-320.9

Quartz sand; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations; mainly fine quartz sand, minor very 

fine and trace medium quartz sand; well sorted quartz sand; 20 percent intergrain porosity; low hydraulic conductivity; 

friable; trace clay matrix; bioturbated; uncommon thick laminations (0.25-1.0 inch thick)

320.9-321.0 No recovery

321.0-324.6

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic l- to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

324.6-326.0 No recovery

326.0-328.6

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic 1- to 6 foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

328.6-331.0 No recovery

331.0-335.0

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic 1- to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

335.0-336.0 No recovery

336.0-339.8

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; immoderate to well sorted quartz sand; 20 percent intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace

clay matrix; bioturbated; cyclic 1- to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; 

thinly laminated to medium bedded in part (0.25 to 6 inches thick)

339.8-341.0 No recovery

341.0-342.5

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic 1- to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

342.5-345.0 No recovery

345.0-348.6

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarse- cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic l- to 6 foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

348.6-350.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-327 test corehole
Appendix--Litholotic Description, Core GL-327 61

350.0-354.1

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic 1-to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

354.1-355.0 No recovery

355.0-357.9

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic 1- to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

357.9-361.0 No recovery

361.0-364.4

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic 1- to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

364.4-366.0 No recovery

366.0-367.6

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic 1- to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

367.6-371.0 No recovery

371.0-375.5

Quartz sand with clay interlaminations and interbeds; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; varying from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly 

medium to coarse quartz sand with minor very fine to medium quartz sand; moderate to well sorted quartz sand; 20 percent 

intergrain porosity in coarse quartz sand; coarser cycle top moderate and finer cycle base low; friable quartz sand; trace clay

matrix; bioturbated; cyclic 1- to 6-foot thick coarsening upward cycles; clay laminations within cycles thin upwards; thinly 

laminated to medium bedded in part (0.25 to 6 inches thick)

375.5-376.0 No recovery

376.0-377.7

Interlaminated mudstone and quartz sand; light olive gray 5Y 6/1 quartz sand and light olive gray 5Y 6/1 to olive gray 

5Y 4/1clay laminations and beds; mainly clay and medium to small pebble-sized quartz sand; very low to low hydraulic 

conductivity; 

377.7-381.0 No recovery

381.0-384.6

Interlaminated mudstone and quartz sand; light olive gray 5Y 6/1 quartz sand and light olive gray 5Y 6/1 to olive gray 

5Y 4/1clay laminations and beds; mainly clay and medium to small pebble-sized quartz sand; very low to low hydraulic 

conductivity; 

384.6-385.1

Quartz sandstone; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; mainly fine to medium 

quartz sand and minor very fine quartz sand; well sorted quartz sand; low hydraulic conductivity; hard; well cemented; 

possible unconformity at 384.6 feet

385.1-424.5 No recovery (probably unconsolidated sand based on gamma ray)

Depth

(feet below 

land surface)

Lithologic description of GL-327 test corehole
62 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

424.5-424.7

Quartz sandstone; yellowish gray sand 5Y 8/1 and light olive gray 5Y 6/1 clay laminations and beds; mainly fine to medium 

quartz sand and minor very fine and coarse to small pebble-sized quartz sand; well sorted quartz sand; low hydraulic 

conductivity; hard; well cemented with lime mudstone matrix; possible unconformity at 384.6 feet

424.7-430.5

Interlaminated mudstone and quartz sand; light olive gray 5Y 6/1 quartz sand and olive gray 5Y 4/1clay laminations and 

beds; mainly clay and very fine quartz sand; very low hydraulic conductivity; bioturbated; clay matrix; abrupt contact or 

unconformity at 424.7 feet

430.5-435.4 Quartz sand with clay matrix; light olive gray 5Y 6/1 quartz sand and olive gray 5Y 4/l clay laminations and beds; mainly 

fine to coarse quartz sand and minor very coarse quartz sand; very low hydraulic conductivity; bioturbated; clay matrix

435.4-436.0 No recovery

436.0-446.5

Quartz sand; light olive gray 5Y 6/1 quartz sand and olive gray 5Y 4/1clay laminations and beds; mainly very fine to very 

coarse quartz sand and minor very coarse quartz sand; 20 percent phosphorite and heavy minerals; low hydraulic conductivity; bioturbated; trace to abundant clay matrix; fuming upward cycle and thicken upward of clay laminations from 446.5 to 

424.7 feet

446.5-453.7 Mudstone; olive gray 5Y 4/1; very low hydraulic conductivity; high-angle slickensides; possible unconformity at 446.5 

suggested by apparent abrupt contact and sharp decrease in gamma ray

453.7-454.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-327 test corehole
Appendix--Litholotic Description, Core GL-329 63

GL-329 Test Corehole

FGS well number W-18075

GWSI number GL-329

Total depth 431 feet

Cored from 0 to 431 feet

County Glades

Location SW, SW, sec. 25, T42S, R31E

Latitude 26° 47′ 7.4′′

Longitude 081° 11′ 13.5′′

Elevation 34 feet

Completion date June 12, 2000

Other types of logs available None

Owner USGS

Driller FGS

Core described by Kevin J. Cunningham

Fill 0 to 17 feet

Undifferentiated 17 to 29 feet

Tamiami Formation 29 to 153.3 feet

Upper Peace River Formation 153.3 to 393.4 feet

Lower Peace River Formation(?) 393.4 to 431 feet

Water-table aquifer 0 to 69.6 feet

Tamiami confining zone 69.6 to 93.2 feet

Lower Tamiami aquifer 93.2 to 206 feet
64 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

Depth

(feet below 

land surface)

Lithologic description of GL-329 test corehole

 0.0-17.0 Fill

17.0-17.1 Peat; black N1; low hydraulic conductivity

17.1-17.4 Quartz sand; brownish gray 5YR 4/1; mainly very fine to fine quartz sand; well sorted quartz sand; 25 percent intergrain 

porosity; moderate hydraulic conductivity; minor organics in matrix

17.4-22.0 No recovery

22.0-24.0 Quartz sand; brownish gray 5YR 4/1; mainly very fine to medium quartz sand; well sorted quartz sand; 20 percent intergrain porosity; moderate hydraulic conductivity; abundant dark organic material in matrix

24.0-24.7

Unconsolidated pelecypod and gastropod lime rudstone and quartz sand matrix; brownish gray 5YR 4/1; mainly very fine to 

medium quartz sand; minor to very large pebble-sized fossils; well sorted quartz sand; very poorly sorted fossils and sand; 

20 percent intergrain porosity; moderate hydraulic conductivity; one sample of hard limestone contains laminated calcrete 

filling voids indicating a possible exposure surface in interval

24.7-28.0 No recovery

28.0-28.5 Pelecypod lime rudstone with chalky lime packstone and grainstone matrix; very pale orange 10YR 8/2; mainly coarse to 

medium pebble-sized pelecypods; moderate hydraulic conductivity

28.5-29.0

Quartz sand; pale yellowish brown 10YR 6/2; mainly very fine to medium quartz sand; minor coarse quartz sand and coarse 

to medium pebble-sized pelecypods; moderately sorted quartz sand; 25 percent intergrain porosity; moderate hydraulic 

conductivity; minor broken pelecypod shells

29.0-30.2

Quartz sand; very light gray N8; mainly fine to medium quartz sand; minor very fine and coarse to very coarse quartz sand 

and very coarse to granule-sized pelecypods; trace medium pebble-sized pelecypods; moderately sorted quartz sand; 

25 percent intergrain porosity; moderate hydraulic conductivity; 20-30 percent broken pelecypod shells

30.2-32.5 No recovery

32.5-32.6

Quartz sand; very light gray N8; mainly fine to medium quartz sand; minor very fine and coarse to very coarse quartz sand 

and very coarse to granule-sized pelecypods; trace medium pebble-sized pelecypods; moderately sorted quartz sand; 

25 percent intergrain porosity; moderate hydraulic conductivity; 20-30 percent broken pelecypod shells

32.6-36.0 No recovery

36.0-36.3 Rubble of loose pelecypod and gastropod shells up to large pebble size and one large pebble composed of laminated 

calcrete, possible exposure surface in interval

36.3-41.0 No recovery

41.0-42.8

Unconsolidated pelecypod lime rudstone with quartz sand matrix; light gray N7; mainly fine to medium quartz sand; minor 

very fine and coarse quartz sand and coarse to granule-sized fossils; well sorted quartz sand; poorly sorted fossils and sand; 

pelecypods, gastropods and barnacles; 20 percent intergrain porosity; moderate hydraulic conductivity

42.8-46.0 No recovery

46.0-46.9

Unconsolidated pelecypod lime rudstone with quartz sand matrix; light gray N7; mainly fine to medium quartz sand; minor 

very fine and coarse quartz sand and coarse to granule-sized fossils; well sorted quartz sand; poorly sorted fossils and sand; 

pelecypods, gastropods and barnacles; 20 percent intergrain porosity; moderate hydraulic conductivity

46.9-51.0 No recovery

51.0-54.3

Quartz sand with abundant broken pelecypod shells; light gray N7; mainly fine to medium quartz sand; minor very fine and 

coarse quartz sand and coarse to granule-sized fossils; well sorted quartz sand; poorly sorted fossils and sand; 20 percent 

intergrain porosity; moderate hydraulic conductivity

54.3-56.0 No recovery
Appendix--Litholotic Description, Core GL-329 65

56.0-58.0

Quartz sand with abundant broken pelecypod shells; very pale orange 10YR 8/2; mainly fine to medium quartz sand; minor 

very fine quartz sand and coarse to granule-sized fossils; well sorted quartz sand; poorly sorted fossils and sand; pelecypods, gastropods and barnacles; 30 percent intergrain porosity; moderate hydraulic conductivity

58.0-61.0 No recovery

61.0-64.5 Quartz sand with abundant broken pelecypod shells; yellowish gray 5Y 8/1; mainly fine quartz sand; minor very fine and 

medium quartz sand and coarse to granule-sized

81.3-86.0 No recovery

86.0-93.2

Quartz sand with abundant broken pelecypod shells; yellowish gray 5Y 8/1; mainly medium quartz sand; minor very fine to 

fine and coarse quartz sand; minor very coarse to granule-sized fossils; well sorted quartz sand; poorly sorted quartz sand 

and shells; 40-50 percent pelecypods, bryozoans, barnacles, gastropods, serpulid tubes; 25 percent intergrain porosity; 

moderate hydraulic conductivity

93.2-96.0 No recovery

96.0-96.7

Quartz sand with abundant broken pelecypod shells; yellowish gray 5Y 8/1; mainly medium quartz sand; minor very fine to 

fine and coarse quartz sand; minor very coarse to granule-sized fossils; well sorted quartz sand; poorly sorted quartz sand 

and shells; 40-50 percent pelecypods, bryozoans, barnacles, gastropods, serpulid tubes; 25 percent intergrain porosity; 

moderate hydraulic conductivity

 96.7-101.0 No recovery

101.0-102.3

Quartz sand with abundant broken pelecypod shells; yellowish gray 5Y 8/1; mainly medium to coarse quartz sand; minor 

very fine to fine quartz sand; minor very coarse to granule-sized fossils; well sorted quartz sand; poorly sorted quartz sand 

and shells; 40-50 percent pelecypods, bryozoans, barnacles, gastropods, serpulid tubes; 25 percent intergrain porosity; 

moderate hydraulic conductivity

102.3-102.5

Quartz sand with abundant broken pelecypod shells and clay matrix and quartz sandstone; yellowish gray 5Y 8/1 and 

medium gray N5 sandstone; mainly medium to coarse quartz sand; minor very fine to fine quartz sand; minor very coarse to 

granule-sized fossils; minor very fine to medium quartz sandstone; well sorted quartz sand; poorly sorted quartz sand and 

shells; 40-50 percent pelecypods, bryozoans, barnacles, gastropods, serpulid tubes; sand 25 percent intergrain porosity and 

sandstone 10 percent intergrain and moldic porosity; low hydraulic conductivity; clay matrix in sand; well-cemented, hard 

quartz sandstone; sandstone is broken into fragments probably by drilling

102.5-106.0 No recovery

106.0-110.3

Quartz sand and quartz sandstone with broken pelecypod shells; yellowish gray 5Y 8/1 and medium gray N5 sandstone; 

mainly fine to medium quartz sand and sandstone; minor fine and coarse quartz sand and sandstone; minor very coarse to 

granule-sized fossils; moderately to well sorted quartz sand and sandstone; poorly sorted quartz sand and shells; 30-40 percent pelecypods; low hydraulic conductivity; minor clay matrix in sand; hard quartz sandstone with a lime mudstone 

matrix; sandstone is broken into fragments probably by drilling

110.3-111.0 No recovery

111.0-112.5

Quartz sand; yellowish gray 5Y 8/1; mainly fine to very coarse quartz sand; minor very fine and granule quartz sand; minor 

medium sand- to small pebble-sized phosphorite grains; poor to moderately sorted quartz sand; poorly sorted quartz sand 

and shells; 10-25 percent pelecypods, barnacles, gastropods; 5 percent phosphorite and heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity

112.5-122.0

Quartz sand; yellowish gray 5Y 8/1; mainly fine to coarse quartz sand; minor very fine and very coarse quartz sand; minor 

medium to very coarse phosphorite grains; moderately sorted quartz sand; trace to 5 percent pelecypods, barnacles, gastropods; 5 percent phosphorite and heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity

122.0-130.5

Quartz sand; yellowish gray 5Y 8/1; mainly fine sand; minor very fine and medium to very coarse quartz sand; minor 

medium to very coarse phosphorite grains; moderately to well sorted quartz sand; 5 percent phosphorite and heavy 

minerals; 25 percent intergrain porosity; low to moderate hydraulic conductivity

130.5-131.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-329 test corehole
66 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

131-131.9

Quartz sand; yellowish gray 5Y 8/1; mainly very fine sand; minor very fine and trace medium to coarse quartz sand; minor 

medium to coarse phosphorite grains; moderately to well sorted quartz sand; 5 percent phosphorite and heavy minerals; 

25 percent intergrain porosity; moderate hydraulic conductivity

131.9-133.8

Quartz sand and sandstone; yellowish gray 5Y 8/1; mainly fine to coarse sand; minor very fine and very coarse to 

granule-sized quartz sand; minor medium to coarse phosphorite grains; poorly to moderately sorted quartz sand; 5 percent 

phosphorite and heavy minerals; minor pelecypods in sandstone

133.8-136.0 No recovery

136.0-141.0

Quartz sand and sandstone; yellowish gray 5Y 8/1; mainly fine to coarse sand; minor very fine and very coarse to granulesized quartz sand; minor medium to coarse phosphorite grains; poorly to moderately sorted quartz sand; minor pelecypods 

in sandstone 5 percent phosphorite and heavy minerals; abundant pelecypods (including oysters); sand 25 percent intergrain 

porosity and sandstone 10 percent intergrain and moldic porosity; sandstone low hydraulic conductivity and sand moderate 

hydraulic conductivity; friable quartz sand; well-cemented, hard sandstone

141.0-142.5

Quartz sandstone; yellowish gray 5Y 8/1; mainly fine to coarse sand; minor very fine and very coarse to granule-sized 

quartz sand; moderately sorted quartz sandstone; 10 percent intergrain and moldic porosity; low hydraulic conductivity; 

well-cemented, hard sandstone

142.5-143.0

Quartz sand; yellowish gray 5Y 8/1; mainly medium to very coarse sand; minor very fine to fine and granule-sized quartz 

sand; minor medium to very coarse phosphorite grains; moderately sorted quartz sand; 5 percent phosphorite and heavy 

minerals; minor broken pelecypod shells; 25 percent intergrain porosity; moderate hydraulic conductivity; friable

143.0-146.0 No recovery

146.0-149.7

Quartz sand and minor quartz sandstone; yellowish gray 5Y 8/1; mainly medium to very coarse sand and sandstone; minor 

very fine to fine and granule-sized quartz sand and sandstone; minor medium to very coarse phosphorite grains; moderately 

sorted quartz sand and sandstone; 5 percent phosphorite and heavy minerals; minor broken pelecypod shells; sand 25 percent intergrain porosity and sandstone intergrain and moldic porosity; sand moderate hydraulic conductivity and sandstone 

low hydraulic conductivity; friable quartz sand; well-cemented, hard sandstone

149.7-151.0 No recovery

 151.0-153.15

Quartz sand; yellowish gray 5Y 8/1; mainly coarse to very coarse sand; minor very fine to medium and granule-size quartz 

sand; minor medium to very coarse phosphorite grains; moderately sorted quartz sand; 5 percent phosphorite and heavy 

minerals; minor broken pelecypod shells; 25 percent intergrain porosity; moderate hydraulic conductivity; friable

 153.15-153.3

Unconsolidated quartz sand-rich, foraminifera lime grainstone; very pale orange 10YR 8/2; minor very fine to fine quartz 

sand; well sorted quartz sand; minor mica; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable; 

abrupt contact above and below

153.3-154.2

Quartz sand; yellowish gray 5Y 8/1; mainly fine to coarse sand; minor very fine and very coarse to granule-size quartz sand; 

minor very fine to granule-size phosphorite grains; moderately sorted quartz sand; 5-10 percent phosphorite and heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity; friable; chalky cement matrix in uppermost 2 inches 

possibly related to an unconformity

154.2-156.0 No recovery

156.0-162.3 Quartz sand; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz sand; poorly to 

moderately sorted quartz sand; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable

162.3-163.9

Quartz sand with pelecypods; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz 

sand; poorly to moderately sorted quartz sand; abundant large pelecypods; 25 percent intergrain porosity; low to moderate 

hydraulic conductivity; friable

163.9-165.3 Quartz sand; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz sand; poorly to 

moderately sorted quartz sand; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable

165.3-166.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-329 test corehole
Appendix--Litholotic Description, Core GL-329 67

166.0-169.3 Quartz sand; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz sand; poorly to 

moderately sorted quartz sand; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable

169.3-171.0 No recovery

171.0-177.0 Quartz sand; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz sand; poorly to 

moderately sorted quartz sand; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable

177.0-178.0 No recovery

178.0-185.0 Quartz sand; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz sand; poorly to 

moderately sorted quartz sand; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable

185.0-186.0 No recovery

186.0-187.5 Quartz sand; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz sand; poorly to 

moderately sorted quartz sand; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable

187.5-190.0 No recovery

190.0-192.0 Quartz sand; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz sand; poorly to 

moderately sorted quartz sand; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable

192.0-195.0 No recovery

195.0-195.1 Rubble of sandstone

195.1-200.0 No recovery

200.0-204.3 Quartz sand; very light gray N8; mainly very fine to coarse sand; minor very coarse to granule-sized quartz sand; poorly to 

moderately sorted quartz sand; 25 percent intergrain porosity; low to moderate hydraulic conductivity; friable

204.3-206.0 No recovery

206.0-206.1

Quartz sandstone; very light gray N8; mainly medium to coarse sand; minor fine and very coarse sized quartz sand; poorly 

to moderately sorted quartz sand; 10 percent intergrain porosity; low hydraulic conductivity; hard, well-cemented sandstone; possible unconformity at top

206.1-210.3

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

210.3-212.0 No recovery

212.0-218.0

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

218.0-220.0 No recovery

220.0-224.0

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

224.0-226.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-329 test corehole
68 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

226.0-230.0

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

230.0-234.0 No recovery

234.0-239.5

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1-to5 foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

239.5-241.0 No recovery

241.0-245.4

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

245.4-251.0 No recovery

251.0-251.6

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

251.6-255.0 No recovery

255.0-256.7

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

256.7-260.0 No recovery

260.0-262.7

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

262.7-270.0 No recovery

270.0-275.4

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine to medium quartz sand with minor very fine and coarse quartz sand to mainly very fine to coarse quartz 

sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate 

hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 

5-foot thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

275.4-280.0 No recovery

280.0-283.8

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

Depth

(feet below 

land surface)

Lithologic description of GL-329 test corehole
Appendix--Litholotic Description, Core GL-329 69

283.8-290.0 No recovery

290.0-292.5

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

292.5-300.0 No recovery

300.0-305.2

Quartz sand with minor clay laminations; yellowish gray5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

305.2-310.0 No recovery

310.0-312.7

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

312.7-320.0 No recovery

320.0-323.0

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

323.0-330.0 No recovery

330.0-334.5

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

334.5-335.0 No recovery

335.0-336.0

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

336.0-341.0 No recovery

341.0-343.3

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

343.3-344.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-329 test corehole
70 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

344.0-346.8

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and light olive gray 5Y 6/1 clay laminations; varying 

from mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic 

conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot 

thick fining upward cycles; clay laminations within cycles thicken and increase in abundance upwards

346.8-350.7

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand with minor medium quartz sand; well sorted quartz 

sand; 5 percent phosphorite and heavy minerals; 25 percent intergrain porosity; low to moderate hydraulic conductivity; 

trace clay matrix

350.7-354.0 No recovery

354.0-370

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand with minor medium quartz sand; well sorted quartz 

sand; 5 percent phosphorite and heavy minerals; 25 percent intergrain porosity; low to moderate hydraulic conductivity; 

trace clay matrix

370.0-373.4

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and olive gray 5Y 4/1 clay laminations; varying from 

mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately 

sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; coarser lower cycle moderate hydraulic conductivity and finer upper cycle low hydraulic conductivity; friable quartz sand; trace clay matrix; cyclic 1- to 5-foot thick fining 

upward cycles; clay laminations within cycles thicken and increase in abundance upwards

373.4-375.0 No recovery

375.0-376.8

Quartz sand with minor clay laminations; yellowish gray 5Y 8/1 sand and olive gray 5Y 4/1 clay laminations; varying from 

mainly fine quartz sand with minor very fine and medium quartz sand to mainly very fine to coarse quartz sand; moderately 

sorted quartz sand; 20-25 percent intergrain porosity in coarse quartz sand; low to moderate hydraulic conductivity; friable 

quartz sand; trace clay matrix

376.8-380.8

Quartz sand; yellowish gray 5Y 8/1; mainly very fine to fine quartz sand with minor medium quartz sand; well sorted quartz 

sand; 5 percent phosphorite and heavy minerals; 25 percent intergrain porosity; low to moderate hydraulic conductivity; 

trace clay matrix

380.8-381.0 No recovery

381.0-384.8

Quartz sand; yellowish gray 5Y 8/1; mainly fine to medium quartz sand with minor very fine and coarse quartz sand; well 

sorted quartz sand; 5 percent phosphorite and heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity; trace clay matrix; uncommon clay laminations

384.8-391.0 No recovery

391.0-392.8

Quartz sand; yellowish gray 5Y 8/1; mainly fine to medium quartz sand with minor very fine and coarse quartz sand; well 

sorted quartz sand; 5 percent phosphorite and heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity; trace clay matrix; uncommon clay laminations

392.8-393.0 No recovery

393.0-393.4 Quartz sand; yellowish gray 5Y 8/1; mainly fine quartz sand with minor very fine and medium quartz sand; well sorted 

quartz sand; moderate hydraulic conductivity

393.4-394.6 Mudstone; olive gray 5Y 4/1; very low hydraulic conductivity

394.6-410.0 No recovery

410.0-410.5 Mudstone; olive gray 5Y 4/1; very low hydraulic conductivity

410.5-411.2 Mudstone; olive gray 5Y 4/1; very low hydraulic conductivity

411.2-416.5 No recovery

416.5-417.5 Mudstone; olive gray 5Y 4/1; very low hydraulic conductivity

417.5-431.0 No recovery

Depth

(feet below 

land surface)

Lithologic description of GL-329 test corehole
Appendix--Litholotic Descriptions, Core HE-1118 71

HE-1118 Test Corehole

Florida Geological Survey well number W-18072

GWSI number HE-1118

Total depth 26.75 feet

Cored from 0 to 26.75 feet

County Hendry

Location NE, sec. 19, T43S, R31E

Latitude 26° 44′ 08′′

Longitude 81° 15′ 55′′

Elevation 22 feet

Completion date July 23, 1999

Other types of logs available Induction, gamma ray, resistivity, spontaneous potential

Owner U.S. Geological Survey

Driller Florida Geological Survey

Core described by Kevin J. Cunningham

Pamlico Sand 0 to 8.5 feet

Caloosahatchee Formation 8.5 to 21 feet

Top Tamiami Formation 21 feet

Water-table aquifer 0 to 8.5 feet

Confining zone 8.5 to 21 feet

Top subaquifer of surficial aquifer 21 feet (electrical logs contributed to selection of tops)
72 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

Depth

(feet below 

land surface)

Lithologic description of HE-1118 test corehole

0.0-2.0

Quartz sand; pale yellowish brown 10YR 6/2; N1 black heavy minerals; mainly very fine to medium quartz sand; minor 

silt-sized quartz, coarse quartz sand, pelecypods up to large pebble size, lithoclasts up to large pebble size, and very fine 

heavy minerals; moderately sorted; subangular to subrounded; 3 percent pelecypods including Chione; trace heavy minerals; 

30 percent intergrain porosity; moderate hydraulic conductivity; soft wet; loose, unconsolidated sand.

2.0-6.0

Quartz sand; mottled very pale orange 10YR 8/2, grayish orange 10YR 7/4; mainly very fine to medium quartz sand; minor 

silt-sized quartz, coarse to very coarse quartz sand, and very fine heavy minerals; moderately sorted; subangular to 

subrounded; trace black heavy minerals; 30 percent intergrain porosity; moderate hydraulic conductivity; soft wet; loose, 

unconsolidated sand.

6.0-7.0 No recovery

7.0-7.9

Quartz sand; mottled very pale orange 10YR 8/2, grayish orange 10YR 7/4; mainly very fine to medium quartz sand; 

minor silt-sized quartz, coarse to very coarse quartz sand, and very fine heavy minerals; moderately sorted; subangular to 

subrounded; trace black heavy minerals; 30 percent intergrain porosity; moderate hydraulic conductivity; soft wet; loose, 

unconsolidated sand.

7.9-10.3 No recovery.

10.3-11.3

Pelecypod lime floatstone with quartz sand-rich, skeletal wackestone matrix; very pale orange 10YR 8/2, grayish orange 

10YR 7/4; mainly very fine to medium quartz sand; minor coarse quartz sand and fine sand-sized to large pebble-sized fossils 

and fossil fragments; well sorted; subangular to subrounded; pelecypods and bryozoans; 20-40 percent quartz sand; 15 percent moldic, root-mold, intergrain porosity; low to moderate hydraulic conductivity; very hard wet; well consolidated; 1-mm 

diameter, semivertical root molds.

11.3-15.0 No recovery.

15.0-16.4

Shelly sandstone; very pale orange 10YR 8/2; mainly clay-size marl, very fine to medium quartz sand and medium sand-sized 

to very large pebble-sized fossils and fossil fragments; well sorted; subangular to subrounded; 40 percent fossils (pelecypods 

and subordinate gastropods); 10 percent intergrain porosity; low hydraulic conductivity; soft wet; marl matrix

16.4-16.7

Pelecypod rudstone with quartz sand-rich marly matrix; pale yellowish brown 10YR 6/2; very fine sand-sized to very large 

pebble-sized fossils and fossil fragments, clay-size marl, very fine to medium quartz sand; minor coarse quartz sand; moderately sorted; subangular to subrounded; pelecypods and subordinate gastropods; 20 percent quartz sand; 10 percent intergrain 

porosity; low hydraulic conductivity; soft wet; marl matrix.

16.7-17.0 No recovery.

17.0-17.6

Pelecypod-oyster rudstone with quartz sand-rich, grain-dominated, skeletal packstone matrix; yellowish gray 5Y 8/1, 

medium light gray N6 to light gray N7; very fine sand-sized to very large pebble-sized fossils and fossil fragments, clay-size 

marl, very fine to medium quartz sand; minor coarse quartz sand; moderately sorted; subangular to subrounded; pelecypods 

and subordinate gastropods; 20 percent quartz sand; 30 percent moldic porosity; low to moderate hydraulic conductivity; soft 

wet; marly matrix.

17.6-21.0 No recovery.

21.0-26.0

Loose pelecypod shells; very pale orange 10YR 8/2, medium dark gray N4 to very light gray N6; coarse sand-sized to 

medium pebble-sized fossils and fossil fragments; minor very fine to medium quartz sand; well sorted; subangular to subrounded; 90 percent pelecypods and subordinate gastropods and barnacles; 5 percent quartz sand; 5 percent clay; 35 percent 

intergrain porosity; moderate hydraulic conductivity to high; unconsolidated, loose shells; most shells broken; very minor 

matrix of sandy clay; interval from 21-26 feet represented by a single sample bag.

26.0-26.8 No recovery.
Appendix--Litholotic Descriptions, Core L-5809 73

L-5809 Test Corehole

Florida Geological Survey well number W-18071

GWSI number L-5809

Total depth 100 feet

Cored from 0 to 100 feet

County Lee

Location NE, sec. 26, T43S, R27E

Latitude 26° 42′ 57′′

Longitude 81° 35′ 27′′

Elevation 8 feet

Completion date July 11, 1999

Other types of logs available Induction, gamma ray, resistivity, spontaneous potential

Owner U.S. Geological Survey

Driller Florida Geological Survey

Core described by Kevin J. Cunningham

Pamlico Sand(?) 0 to 2.6 feet

Bee Branch Member of Caloosahatchee Marl(?) 2.6 to 4.5 feet

Buckingham Member of Tamiami Formation 4.5 to 38.9 feet

Peace River Formation 38.9 to 100 feet

Water-table aquifer 0 to 4.5 feet

Upper confining unit 4.5 to 40 feet

Clastic zone of sandstone aquifer 40 to 90.75 feet

Top carbonate zone of sandstone aquifer 90.75 feet

Note Well had artesian flow after reaching total depth, possibly from the carbonate zone of the sandstone aquifer
74 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

Depth (feet 

below land 

surface)

Lithologic description of L-5809 test corehole

0.0-2.6

Quartz sand; light brownish gray 5YR 6/1, dark yellowish brown 10YR 4/2, dusky yellowish brown 10YR 2/2; mainly very 

fine to fine quartz sand; minor silt-sized quartz and medium quartz sand; well sorted; subangular to subrounded; trace clay in 

lower part of interval; 15-25 percent intergrain porosity; low to moderate hydraulic conductivity; soft wet; loose sand; abundant organics particles; recent rootlets.

2.6-4.5

Pelecypod lime floatstone with skeletal grainstone and quartz sand-rich lime mudstone matrix; very pale orange 10YR 8/2, 

moderate yellowish brown 10YR 5/4; mainly medium sand-sized to granule-sized fossil fragments and lime mud; minor very 

fine to fine quartz sand and pebble-sized fossils; well sorted; angular to subrounded; <30 percent quartz sand; 20 percent 

vuggy and micro porosity; low to moderate hydraulic conductivity; very hard to firm wet; weathered to a chalky texture in 

part; mostly samples of rubble.

4.5-6.6 Marl; very pale orange 10YR 8/2; mainly clay-sized micrite and clay; minor quartz silt and very fine to very large pebble-sized

fossils; <5 percent skeletal fragments and pelecypods; very low porosity; very low hydraulic conductivity; firm wet; hard dry.

6.6-7.0 No recovery.

 7.0-10.9 Marl; very pale orange 10YR 8/2; mainly clay-sized micrite and clay; minor quartz silt and very fine to very large pebble-sized

fossils; <5 percent skeletal fragments and pelecypods; very low porosity; very low hydraulic conductivity; firm wet; hard dry.

10.9-12.0 No recovery.

12.0-13.1 Marl; very pale orange 10YR 8/2; mainly clay-sized micrite and clay; minor quartz silt and very fine to very large pebble-sized

fossils; <5 percent skeletal fragments and pelecypods; very low porosity; very low hydraulic conductivity; firm wet; hard dry.

13.1-14.0

Marly terrigenous mudstone; yellowish gray 5Y 8/1, very pale orange 10YR 8/2; mainly clay and clay-sized micrite; minor 

very fine to fine quartz sand; 5-20 percent quartz sand; 5-10 percent small benthic foraminifers; trace shark’s teeth and fish 

scales; subangular to subrounded; very low porosity; very low hydraulic conductivity; firm wet; hard dry.

14.0-16.8

Marly terrigenous mudstone; light olive gray 5Y 6/1 and 5Y 5/2; dark yellowish orange 10YR 6/6 phosphate grains; mainly 

clay and clay-sized micrite; minor very fine to fine quartz sand and very fine to fine phosphate grains; 5-20 percent quartz 

sand; 5-10 percent small benthic foraminifers; <5 percent phosphate grains; trace shark’s teeth and fish scales; subangular to 

subrounded; very low porosity; very low hydraulic conductivity; firm wet; hard dry.

16.8-17.0 No recovery.

17.0-21.0

Marly terrigenous mudstone; light olive gray 5Y 6/1 and 5Y 5/2; dark yellowish orange 10YR 6/6 phosphate grains; mainly 

clay and clay-sized micrite; minor very fine to fine quartz sand and very fine to fine phosphate grains; 5-20 percent quartz 

sand; 5-10 percent small benthic foraminifers; <5 percent phosphate grains; trace shark’s teeth and fish scales; subangular to 

subrounded; very low porosity; very low hydraulic conductivity; firm wet; hard dry.

21.0-22.0 No recovery.

22.0-26.2

Terrigenous mudstone; light olive gray 5Y 6/1; dark yellowish orange 10YR 6/6 phosphate grains; mainly clay; minor very 

fine to fine quartz sand and very fine to fine phosphate grains; 5-20 percent quartz sand; <10 percent small benthic foraminifers and <20 percent phosphate grains in sand laminations; trace shark’s teeth and fish scales; angular to subrounded; very 

low porosity; very low hydraulic conductivity; firm wet; hard dry; sand occurs in thin to thick laminations.

26.2-26.6

Quartz sand with clay matrix; yellowish gray 5Y 7/2; dark yellowish orange 10YR 6/6 phosphate grains; mainly very fine 

quartz sand; minor fine quartz sand and very fine to fine phosphate grains; well sorted; subangular to subrounded; 10 percent 

small benthic foraminifers; 15 percent phosphate grains; 15 percent intergrain porosity; low hydraulic conductivity; soft wet.

26.6-27.0 No recovery.

27.0-28.5

Quartz sand with clay matrix; yellowish gray 5Y 7/2; dark yellowish orange 10YR 6/6 phosphate grains; mainly very fine 

quartz sand; minor fine quartz sand and very fine to fine phosphate grains; well sorted; subangular to subrounded; 10 percent 

small benthic foraminifers; 15 percent phosphate grains; 5-15 percent intergrain porosity; very low to low hydraulic conductivity; soft wet; thin to thick laminations and thin beds of clay, quartz sand and phosphate sand; fines upward to a clay cap.

28.5-31.5

Quartz sand with clay matrix; yellowish gray 5Y 8/1, light olive gray 5Y 6/1; moderate yellowish brown 10YR 5/4 and 

brownish gray 5YR 4/1 phosphate grains; mainly very fine quartz sand; minor fine quartz sand and very fine to fine phosphate grains; well sorted; subangular to subrounded; 40 percent phosphate grains; 1 percent small benthic foraminifers; trace 

pelecypods, fish scales; 5-15 percent intergrain porosity; very low to low hydraulic conductivity; soft wet; thin to thick laminations and thin beds of clay, quartz sand and phosphate sand; fines upward to a clay cap; possible mud cracks at 30.9 feet.
Appendix--Litholotic Descriptions, Core L-5809 75

31.5-36.8

Interbedded terrigenous mudstone, quartz sand and phosphate sand; yellowish gray 5Y 8/1, light olive gray 5Y 6/1, olive gray 

5Y 4/1; black N1 phosphate grains; mainly very fine quartz sand; minor fine quartz sand and very fine to fine phosphate 

grains; well sorted; subangular to subrounded; 40 percent phosphate grains; 1 percent small benthic foraminifers; trace 

pelecypods, fish scales, siliceous spicules; 5-15 percent intergrain porosity; very low to moderate hydraulic conductivity; soft 

wet; thin to thick laminations and thin beds of clay, quartz sand and phosphate sand.

36.8-37.0 Dolosilt; light olive gray 5Y 6/1; mainly silt-sized dolomite; 5 percent microporosity; very low hydraulic conductivity.

37.0-37.6

Quartz sand; light olive gray 5Y 6/1; black N1 phosphate grains; mainly very fine quartz sand; minor fine to small pebblesized quartz sand and very fine to small pebble-sized phosphate grains; moderately sorted; subangular to subrounded; 25 percent phosphate grains; 15 percent intergrain porosity; low hydraulic conductivity; soft wet; base of fining upward unit with 

top at 31.5 feet; possible erosional unconformity at 37.6 feet.

37.5-38.9

Pelecypod lime floatstone with quartz sand-rich lime mudstone matrix; yellowish gray 5Y 8/1; mainly fine quartz sand; minor 

very fine to small pebble-sized quartz and up to very large pebble-sized fossils; moderately sorted; subangular to subrounded; 

pelecypods and minor cerithiids(?); 10 percent intergrain porosity; low hydraulic conductivity; hard wet; limestone appears 

chalky and weathered, possible subaerial unconformity at top.

38.9-40.0

Quartz sand; light olive gray 5Y 6/1; black N1 phosphate grains; mainly very fine quartz sand; minor fine to small pebblesized quartz sand and very fine to granule-sized phosphate grains; moderately sorted; subangular to subrounded; 3 percent 

phosphate grains; 10-25 percent intergrain porosity; low to moderate hydraulic conductivity; soft to firm wet; grades upward 

from clean sand at base to micrite matrix at top.

40.0-41.0 No recovery.

41.0-44.6

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly fine to medium quartz sand; minor very fine and 

coarse to granule-sized quartz sand, very fine to granule-sized phosphate grains and very fine heavy minerals; moderately 

sorted; subangular to subrounded; 3 percent phosphate grains; trace heavy minerals; 25 percent intergrain porosity; moderate 

hydraulic conductivity; soft wet; friable; frosted quartz sand grains; trace very irregular clay laminations.

44.6-46.0 No recovery.

46.0-48.0

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly fine to medium quartz sand; minor very fine and 

coarse to granule-sized quartz sand, very fine to granule-sized phosphate grains and very fine heavy minerals; moderately 

sorted; subangular to subrounded; 3 percent phosphate grains; trace heavy minerals; 25 percent intergrain porosity; moderate 

hydraulic conductivity; soft wet; friable; minor frosted quartz grains.

48.0-50.0 No recovery.

50.0-55.3

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly very fine to medium quartz sand; minor coarse quartz 

sand, very fine to medium phosphate grains, very fine heavy minerals; moderately to well sorted; subangular to subrounded; 

3 percent phosphate grains; trace mica and heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity; 

soft wet; friable; minor frosted quartz grains.

55.3-55.5 No recovery.

55.5-59.5

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly very fine to fine quartz sand; minor medium quartz sand, 

very fine to fine phosphate grains and very fine heavy minerals; well sorted; subangular to subrounded; 3 percent phosphate 

grains; trace mica and heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; friable.

59.5-60.5 No recovery.

60.5-63.7

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly very fine to fine quartz sand; minor medium quartz sand, 

very fine to fine phosphate grains and very fine heavy minerals; well sorted; subangular to subrounded; 3 percent phosphate 

grains; trace mica and heavy minerals; 20 percent intergrain porosity; moderate hydraulic conductivity; soft wet; friable.

63.7-65.5

Quartz sand; yellowish gray 5Y 8/1, light olive gray 5Y 6/1; black N1 phosphate grains; mainly very fine to fine quartz sand; 

minor medium to coarse quartz sand, very fine to medium phosphate grains and very fine heavy minerals; moderately sorted; 

subangular to subrounded; 2 percent phosphate grains; minor clay matrix and heavy minerals; 15 percent intergrain porosity; 

low hydraulic conductivity; soft wet; friable.

65.5-66.0 No recovery.

Depth (feet 

below land 

surface)

Lithologic description of L-5809 test corehole
76 Surface-Geophysical Characterization of Ground-Water Systems of the Caloosahatchee River Basin, Southern Fla.

66-67.5

Quartz sand; yellowish gray 5Y 8/1, light olive gray 5Y 6/1; black N1 phosphate grains; mainly very fine to medium quartz 

sand; minor coarse quartz sand, very fine to medium phosphate grains and very fine heavy minerals; moderately sorted; subangular to subrounded; 2 percent phosphate grains; minor clay matrix and heavy minerals; 15 percent intergrain porosity; low 

hydraulic conductivity; soft wet; friable.

67.5-68.5

Quartz sand; light olive gray 5Y 6/1; black N1 phosphate grains; mainly very fine to medium quartz sand; minor coarse 

quartz sand, very fine to medium phosphate grains and very fine heavy minerals; moderately sorted; subangular to subrounded; 2 percent phosphate grains; abundant clay matrix; trace heavy minerals; 10 percent intergrain porosity; low 

hydraulic conductivity; soft wet; friable.

68.5-70.5

Quartz sand; yellowish gray 5Y 8/1, light olive gray 5Y 6/1; black N1 phosphate grains; mainly very fine to medium quartz 

sand; minor coarse quartz sand, very fine to medium phosphate grains and very fine heavy minerals; moderately sorted; subangular to subrounded; 2 percent phosphate grains; minor clay matrix and heavy minerals; 15 percent intergrain porosity; low 

hydraulic conductivity; soft wet; friable.

70.5-71.0 No recovery.

71.0-71.5

Quartz sand; yellowish gray 5Y 8/1, light olive gray 5Y 6/1; black N1 phosphate grains; mainly very fine to medium quartz 

sand; minor coarse quartz sand, very fine to medium phosphate grains and very fine heavy minerals; moderately sorted; subangular to subrounded; 2 percent phosphate grains; minor clay matrix and heavy minerals; 15 percent intergrain porosity; low 

hydraulic conductivity; soft wet; friable.

71.5-74.4

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly fine to medium quartz sand; minor very fine and 

coarse to granule-sized quartz sand, very fine to very coarse phosphate grains and very fine heavy minerals; moderately 

sorted; subangular to subrounded; 2 percent phosphate grains; trace clay matrix; minor heavy minerals; 15-25 percent 

intergrain porosity; moderate hydraulic conductivity; soft wet; friable.

74.4-75.5 No recovery

75.5-80.2

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly fine to medium quartz sand; minor very fine and 

coarse to granule-sized quartz sand, very fine to very coarse phosphate grains and very fine heavy minerals; moderately 

sorted; subangular to subrounded; 2 percent phosphate grains; trace clay matrix; minor heavy minerals; 25 percent intergrain 

porosity; moderate hydraulic conductivity; soft wet; friable.

80.2-80.5 No recovery.

80.5-80.7

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly fine to medium quartz sand; minor very fine and 

coarse to medium pebble-sized quartz sand, very fine to small pebble-sized phosphate grains and very fine heavy minerals; 

moderately sorted; subangular to subrounded; 2 percent phosphate grains; minor heavy minerals; 25 percent intergrain 

porosity; moderate hydraulic conductivity; soft wet; friable.

80.7-85.5 No recovery.

85.5-87.5

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly very fine to fine quartz sand; minor medium quartz 

sand, very fine to fine phosphate grains and very fine heavy minerals; well sorted; subangular to subrounded; 2 percent phosphate grains; minor heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; friable; trace 

thin clay laminations.

87.5-90.5 No recovery.

90.5-90.7

Quartz sand; yellowish gray 5Y 8/1; black N1 phosphate grains; mainly very fine to fine quartz sand; minor medium quartz 

sand, very fine to fine phosphate grains and very fine heavy minerals; well sorted; subangular to subrounded; 2 percent phosphate grains; minor heavy minerals; 25 percent intergrain porosity; moderate hydraulic conductivity; soft wet; friable; trace 

thin clay laminations; a few clasts of up to medium pebble-sized quartz sandstone and phosphate above the basal surface at 

90.75 that are loose in core box.

90.8-91.7

Pelecypod lime floatstone with skeletal wackestone matrix; very light gray N8; mainly micrite; minor very fine to pebblesized fossils; skeletal fragments and pelecypods; 20 percent moldic porosity; low hydraulic conductivity; hard wet; very well 

consolidated; minor root molds about 1 mm in diameter; very local blackened upper surface.

91.7-94.0

Pelecypod lime rudstone with skeletal grainstone to grain-dominated packstone matrix; grayish orange 10YR 7/4; mainly 

very fine sand-sized to large pebble-sized fossils; pelecypods, skeletal fragments, gastropods; trace corals and bryozoans; 

30 percent moldic and intergrain porosity; high hydraulic conductivity; hard wet; well consolidated.

94.0-100.0 No recovery.

Depth (feet 

below land 

surface)

Lithologic description of L-5809 test corehole