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Durward H. Boggess

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STATE OF FLORIDA
DEPARTMENT OF ENVIRONMENTAL PROTECTION
David B. Struhs, Secretary

DIVISION OF RESOURCE ASSESSMENT AND MANAGEMENT
Edwin J. Conklin, Director

FLORIDA GEOLOGICAL SURVEY
Walter Schmidt, State Geologist and Chief

SPECIAL PUBLICATION NO. 49

GEOLOGY AND HYDROLOGY OF LEE COUNTY, FLORIDA
DURWARD H. BOGGESS MEMORIAL SYMPOSIUM

EDITED BY
Thomas M. Missimer and Thomas M. Scott

Published for the
FLORIDA GEOLOGICAL SURVEY
Tallahassee
2001

LETTER OF TRANSMITTAL

FLORIDA GEOLOGICAL SURVEY
Tallahassee
2001

Governor Jeb Bush
Tallahassee, Florida

Dear Governor Bush:

The Florida Geological Survey, Division of Resource Assessment and Management, Department
of Environmental Protection, is publishing as Special Publication No. 49, Geology and
Hydrogeology of Lee County, Florida, Durward H. Boggess Memorial Symposium, edited by
Thomas M. Missimer and Thomas M. Scott. The information presented herein is valuable in
understanding the geology of the aquifers underlying this growing region. It will be useful to state
planners and land managers who must make informed decisions about local aquifer uses and
resources.

Respectfully,

Walter Schmidt, Ph.D.
State Geologist and Chief
Florida Geological Survey

Printed for the
Florida Geological Survey

Tallahassee
2001

ISSN 0085-0640

iv

CONTENTS

Dedication and Editor's Preface ........................................ ...... vi
A cknow ledgem ents ........................................................ vii
List of Participants and Contributors .................................... ...... viii

Contributions of Durward H. Boggess to the hydrology and geology of Lee County, Florida
by Thom as M M issim er . ......... ........................................... 1

GEOLOGY

The Surficial Geology of Lee County and the Caloosahatchee Basin, by Thomas M. Scott and
T hom as M M issim er ...................................................... 17

Late Neogene Geology of Northwestern Lee county, Florida, by Thomas M. Missimer ..... 21

Sequence Stratigraphy of a Carbonate Ramp and Bounding Silicielasties (late Miocene -
Pliocene), Southern Florida, by Kevin J. Cunningham, David Burky, Tokiyuki Sato, John A.
Barron, Laura A. Guertin, and Ronald S. Reese ................................... 35

Late Paleogene and Neogene Chronostratigraphy of Lee County, Florida,
by Thomas M. Missimer . ......... .......................................... 67

HYDROGEOLOGY

Hydrogeology of Lee County, Florida, by Thomas M. Missimer and W. Kirk Martin ........ 91

Water Level Maps of the Primary Aquifers in the Lower West Coast of Florida
by Terry Bengtsson and Hope Radin .................................. . ...... 139

Hydrogeologic Implications of Uranium-rich Phosphate in Northeastern Lee County
by J. Michael W einberg and James B. Cowant .................................. 151

Hydrogeology of the Lower Floridian Aquifer "Boulder Zone" of Southwest Florida
by Robert G. Maliva, Charles W Walker, and Edward X. Callahan .............. . . 167

HYDROLOGY AND WATER QUALITY

Caloosahatchee Basin integrated surface water groundwater model
by Clyde Dabbs, Torten Jacobsen, Douglas Moulton, and Akin Owosina .......... .... .183

Surface Water Management in Lee County, by Archie T Grant and Andrew D. Tilton .... 197

Seagrass meadow hourly dissolved oxygen recordings, central Estero Bay, Lee County
by Hugh J. Mitchell-Tapping, Thomas J. Lee, Cathy R. Williams, and Thomas Winter ... .205

The Lee County Abandoned Well Program, by Jack McCoy .................. . . 227

DEDICATION AND EDITOR'S PREFACE

A special symposium on the geology and hydrology of Lee County, Florida was held in Fort
Myers on November 18 and 19, 1999. This symposium was held as part of the 9th Southwest
Florida Water Resources Conference. The conference was held in honor of Durward H.
Boggess, who made significant contributions to the understanding of the geology and hydrology
of Lee County.

Durward H. Boggess was a hydrologist with the U.S. Geological Survey in Fort Myers from
1966 to 1979. During this time period, Lee County was one of the most rapidly growing regions
in the United States. Little was known about the geology and the aquifer system beneath the
county, as evidenced by the small number of publications on this region by the Florida Geological
Survey. Durward H. Boggess developed a geologic and hydrologic database that allowed the
development of future water supplies to occur with a sound scientific basis.

Most of the papers published in this volume were presented at the conference and a few
others were added to make the volume as complete as possible in terms of recent knowledge
on the geology and hydrology of Lee County. The volume is organized with a discussion of the
contributions of Durward Boggess, followed by a series of papers on the geology of the county.
Based on the geologic framework, a series of papers follows on the hydrogeology of the county.
Finally, some papers on the surface-water hydrology and water quality of the county complete
the volume.

Lee County occurs in the geographic middle of the southern part of the Florida Platform.
The geology of this region is rather unique, because there is a succession of carbonate
sediments followed by a complex mix of carbonate and siliciclastic sediments (beginning in the
Oligocene). The geographic location of the county and the mixing of the sediments caused the
aquifer system beneath the county to be quite complex with numerous different aquifers present.
Over 12 aquifers or major water-bearing zones occur beneath any given area of the county. It
is critical to understand the geology and hydrology of this area, because many of the aquifer are
or will be used for water supply. Also, the deep aquifer system is used for the disposal of liquid
wastes, such as oil field brines, concentrates from desalination plants, and treated domestic
wastewater.

It is extremely important that recent information on the geology and hydrology of this as well
as other regions of Florida be made available to environmental managers and the general pub-
lic in a timely manner.

Thomas M. Missimer Thomas M. Scott
Fort Myers Tallahassee

ACKNOWLEDGEMENTS

The editors wish to acknowledge a number of individuals whose efforts made this sym-
posium and the resulting special publication possible. Perhaps the most difficult task, aside from
finding the time to prepare a paper, is the meeting planning and organization. This task fell on
the conference host committee, whose efforts are greatly appreciated: Ron Edenfield (Chair),
Susan Brookman, John Capece, Clyde Dabbs, Win Everham, Samy Faried, Lynne Felknor,
Jennifer Flaitz, Ron Hamel, Kurt Harclerode, Steve Kempton, Bonnie Kranzer, Jeff Krieger, Tom
Missimer, John Musser, Dan VanNorman, and Sean Weeks.
The editors extend a special thanks to Mrs. Durward Boggess for providing the photo of
her husband used inside the front cover of the publication. And we thank Frank Rupert for com-
piling the different text and graphics formats into QuarkXPress for publication.

LIST OF PARTICIPANTS AND CONTRIBUTORS

John Barron, U.S. Geological Survey, 345 Middlefield rd., Menlo Park, CA 94025
Terry Bengtsson, SFWMD, 2301 McGregor Blvd, Fort Myers, FL 33901
David Bukrey, U.S. Geological Survey, 345 Middlefield rd., Menlo Park, CA 94025
Edward Callahan, Florida Geophysical Logging, Inc., 15465 Pine Ridge Rd., Fort Myers, FL
33908
James Cowart, Department of Geological Sciences, Florida State University, Tallahassee, FL
32306
Kevin Cunningham, U.S. Geological Survey, 9100 NW 36th Street, Suite 107, Miami, FL
33178
Clyde Dabbs, SFWMD, 2301 McGregor Blvd, Fort Myers, FL 33901
Archie Grant, Johnson Engineering, Inc.P.O. Box 1550, Fort Myers. FL 33902
Laura Guertin, Mary Washington College, Fredericksburg, VA 22401
Torsten Jacobsen, DHI Inc., Eight Neshaminy Interplex, Suite 219, Trevose, PA 19053
Thomas Lee, Ostego Bay Foundation Inc./Estero Bay Marine Laboratory Inc., P.O.
Box 0875, Fort Myers Beach, FL 33931
Robert Maliva, CDM/Missimer International, Inc., 8140 College Parkway, Suite 202, Fort
Myers, FL 33919
Joseph Mallon, Ostego Bay Foundation Inc./Estero Bay Marine Laboratory Inc., P.O.
Box 0875, Fort Myers Beach, FL 33931
Kirk Martin, CDM/Missimer International, Inc., 8140 College Parkway, Suite 202, Fort
Myers, FL 33919
Jack McCoy, Lee County Natural Resources Division, P.O. Box 398, Fort Myers, FL 33902
Thomas Missimer, CDM/Missimer International, Inc., 8140 College Parkway, Suite 202, Fort
Myers, FL 33919
Hugh Mitchell-Tapping, Ostego Bay Foundation Inc./Estero Bay Marine Laboratory Inc., P.O.
Box 0875,Fort Myers Beach, FL 33931
Douglas Moulton, C.D.M., 2301 Maitland Center Parkway, Suite 301, Maitland, FL 32751
Akin Owosina, SFWMD, 2301 McGregor Blvd, Fort Myers, FL 33901
Hope Radin, SFWMD, 3301 Gun Club Rd., West Palm Beach, FL
Ronald Reese, U.S. Geological Survey, 9100 NW 36th Street, Suite 107, Miami, FL 33178
Thomas Scott, Florida Geological Survey, 903 West Tennessee St., Tallahassee, FL 32304'
Tokiyuki Sato, Institute of Applied Earth Sciences Mining College, Akita University, Tegata-
Gakuencho 1-1, Akita, 010, Japan
Andrew Tilton, Johnson Engineering, Inc.P.O. Box 1550, Fort Myers. FL 33902
Leslie Wadderburn, Consulting Hydrogelogist
Charles Walker, CDM/Missimer International, Inc., 8140 College Parkway, Suite 202, Fort
Myers, FL 33919
Micheal Weinberg, Water Resource Solutions, 428 Pine Island Rd. SW, Cape Coral, FL 33991
Cathy Williams, Ostego Bay Foundation Inc./Estero Bay Marine Laboratory Inc., P.O.
Box 0875, Fort Myers Beach, FL 33931
Thomas Winter, Ostego Bay Foundation Inc./Estero Bay Marine Laboratory Inc., P.O.
Box 0875, Fort Myers Beach, FL 33931

FLORIDA GEOLOGICAL SURVEY

CONTRIBUTIONS OF DURWARD H. BOGGESS
TO THE HYDROLOGY AND GEOLOGY
OF LEE COUNTY, FLORIDA

Thomas M. Missimer,
CDM/Missimer International, Inc., 8140 College Parkway, Suite 202, Fort Myers, Florida 33919

ABSTRACT

Sparse investigation of the hydrology and geology of Lee County, Florida was conducted
before Durward Boggess established the U.S. Geological Survey office in Fort Myers during
1966. Past work included a general description of the geology along the banks of the
Caloosahatchee River (Heilprin, Dall, DuBar) and some paleontological studies of barrow pit
spoils piles and some surface-water studies in a few streams. Durward Boggess quickly grasped
the water-supply problems of Lee County and recognized the need for both surface-water and
groundwater data.
The completion of the Okeechobee Waterway (construction of S-79) occurred only a short
time before Mr. Boggess moved to Lee County. In 1966, the Caloosahatchee River was believed
to be the most reliable source of water supply for the City of Fort Myers and the unincorporated
areas of Lee County. Intakes were designed and constructed about 1 mile upstream of the W.
P. Franklin Dam (S-79) on the river. These intakes fed the artificial recharge system for the City
of Fort Myers Wellfield via a pipeline and the new Lee County Water Treatment Plant. Mr.
Boggess was concerned about the proximity of the intake structures to the lock through S-79.
Each time a boat passed through the lock in dry periods, a slug of saltwater moved upstream.
So, his first work in Lee County was on how to control the upstream movement of saline water
in the Caloosahatchee River.
Among the many contributions made by Durward Boggess to the study and management of
water resources in Lee County were: 1) the establishment of permanent gaging stations on the
Caloosahatchee River and other larger streams in Lee County, 2) the establishment of the crest-
stage gages in Lee County to assess flooding and drainage problems, 3) the creation of an
extensive data base on the geology and hydrology of Lee County, 4) the initial mapping of the
shallow and intermediate aquifer systems, 5) the definition and naming of the principal aquifers
used in Lee County, including the Lower Hawthorn Aquifer, the Upper Hawthorn Aquifer (now
termed the Mid-Hawthorn Aquifer), the Sandstone Aquifer, and the water-table aquifer, 6) the
recognition that brackish, saline-water in the Lower Hawthorn Aquifer was a resource to be con-
served and would be a water supply for the future, 7) helped establish how saline water inter-
acted with the shallow aquifer system of Sanibel Island and helped established development
practices that would be fundamental to the writing of the City of Sanibel Comprehensive Land
Use Plan, 8) recognized that cut and fill landfills, which were the state-of-the-art landfill type at
that time, were causing groundwater contamination, 9) suggested that the shallow groundwater
system in southern and eastern Lee County would be the source for future public water supplies
in Lee County, 10) recognized that the Mid-Hawthorn Aquifer was being over-pumped in Cape
Coral and Fort Myers, 11) recognized that improper well construction practices were causing
contamination of the freshwater resources of the county with saline water, which led to the adop-
tion of new well construction codes and the establishment of a well plugging program, 12) rec-
ognized that over-drainage of the Lehigh Acres area of Lee County was adversely affecting the
water resources and wetlands, and 13) convinced the Lee County government that the planning
process should include the management of the groundwater resources.
Without the scientific expertise and insight of Durward Boggess, Lee County would have had

SPECIAL PUBLICATION NO. 49

severe water supply problems many years ago. Durward Boggess believed that it was very
important for the public to understand how the hydrologic system functioned and he spent much
time with the media and interested citizens to help educate them. He was one dedicated indi-
vidual, who cared about Southwest Florida, that made a difference in molding the future man-
agement of water resources.

INTRODUCTION

Prior to the 1960's, geological and hydrological work on Lee County, Florida was very limit-
ed (Figure 1). Initial geological and paleontological investigation on this region began in the late
1880's. The first description of geological work in southwestern Florida was that of Heilprin
(1887), who wrote "Prior to our visit, the only portion of the state that had been examined geo-
logically, or on which a geological report had been prepared, was the region lying north of a line
running almost due northeast from the Manatee River, just south of Tampa Bay, to the east coast.
Below all this was conjectural, although the existence of certain limestones of undetermined age
was hinted at, or even located, by a number of causal observers (Tuomey, Conrad) who chanced
to navigate some of the outer waters. Such a limestone was reported by Tuomey to be found in
Charlotte Harbor, but the exact locality of its occurrence is not noted." Heilprin (1887) described
the geology and paleontology of the banks of the Caloosahatchee River from Fort Myers east to
past Labelle in Hendry County. Rather extensive works on the paleontology of the exposed
Pliocene and Pleistocene sediments along the Caloosahatchee River, Shell and Alligator creeks
(Charlotte County) were made by William H. Dall of the Wagner Free Institute of Philadelphia.
Dall (1890-1903) described many of the most common mollusk species of the Neogene
sediments. Additional paleontological investigations were conducted in parts of Lee County by
Wendall C. Mansfield (an original field assistant of Dall), Druid Wilson, Helen I. Tucker, and Axel
Olsson. Some of the data collected are published in Tucker and Wilson (1932-33) and Olsson
and Harbison (1953), but no stratigraphic descriptions were made. Petroleum exploration began
in Southwest Florida in the 1930's with a number of "shallow" dry holes being drilled in Charlotte,
Lee, and Collier counties. Few data were preserved from this early deep exploration work.
Detailed investigations of the exposed Neogene paleontology and geology of the
Caloosahatchee River from Lee County and Hendry County were published by DuBar (1958)
with another study conducted in Charlotte County (DuBar, 1962). A surface geological map of
the area was published by Parker and Cooke (1944), based on minimal data collected from
exposures and barrow pits.
Some reconnaissance work on the hydrogeology of the Southwest Florida region was
undertaken in the 1940's as a part of extensive studies directed by Gerald Parker of the U. S.
Geological Survey. Some preliminary data on rainfall along with some logs of wells in Hendry
County immediately to the east of Lee County were published in Parker et al. (1955). A study of
surface water flows and surface-water quality in a few streams in Lee County was published by
Kenner and Brown (1956). The U. S. Geological District office in Tallahassee was concerned
about the lack of hydrogeologic data and aquifer definitions in the early 1960's and Nevin Hoy
was assigned to make an assessment of the hydrology and geology of Lee County. A draft report
by Hoy was submitted to the Florida Geological Survey but not published, because of insufficient
data.
The U. S. Geological Survey decided to open a field office in Fort Myers under the direction
of the Subdistrict office in Miami during 1965. A senior hydrologist with the U.S.G.S. in Maryland,
Durward H. Boggess, was assigned to open the office. His assignment was to assess the water
resource problems of Lee County, to develop a hydrogeologic data base, and to develop fund-
ing sources for conducting hydrologic investigations.

FLORIDA GEOLOGICAL SURVEY

SCALE

25 MILES

40 KILOMETERS

Figure 1. Map of Lee County showing locations mentioned in text.

In 1966, Lee County was a rural region, with a predominantly agricultural economy and a devel-
oping tourist industry. Population growth was beginning to accelerate and a number of water
supply problems were becoming evident. Water supplies for the new residents of the county
along with the expanding agricultural uses were beginning to become problematical. Durward
Boggess arrived in Lee County in 1966 at a critical time in its development history. He made an
immediate and long-term impact on the management of the water resources of Lee County. The
problems he outlined in "Water-Supply Problems in Southwest Florida" (Boggess, 1968) set the
beginning of his work on the geology and hydrology of Lee County. During the 13 years of serv-
ice with the U. S. Geological Survey in Lee County, Durward Boggess made numerous contri-
butions to the geologic and hydrologic knowledge of Southwest Florida. This paper outlines only
a few of these contributions.

SPECIAL PUBLICATION NO. 49

The Caloosahatchee River as a Water Supply Source
Construction of the Okeechobee Waterway was completed only about a year before
Durward Boggess came to Lee County. In 1966, the City of Fort Myers was having serious prob-
lems with its wellfield, which was the only potable public water-supply source for the city.
Therefore, the city decided to pump surface water from the Caloosahatchee River at the
upstream side of the primary salinity control structure (S-79) to the wellfield in order to recharge
the system via a series of canals. An assessment of the City of Fort Myers wellfield and the
Caloosahatchee River recharge system lead to the first Boggess report on the hydrogeology of
Southwest Florida (Boggess, 1968). Use of the Caloosahatchee River as a water supply source
had some serious problems, because of the lock in the river, which allowed boat traffic to use the
waterway. Each time a boat passed through the lock, a slug of saline-water was allowed to
migrate upstream. This problem was recognized early by Durward Boggess and he assisted the
City of Fort Myers in studying the problem by conducting controlled flushing experiments with the
U. S. Army Corps of Engineers, who were responsible for operation of the waterway (Boggess,
1970a). A cooperative program was initiated between the U. S. Geological Survey and the City
of Fort Myers to establish the first locally funded hydrological studies in Southwest Florida.
Boggess continued to study the saline-water intrusion problem in the river for many years
(Boggess, 1970b; 1972) until the discharge of water from Lake Okeechobee and a bubble cur-
tain were used to control the upstream movement of the saline water.
Unfortunately, the City of Fort Myers and later, Lee County Utilities, did not heed the advice
of Durward Boggess who suggested that the water supply intakes in the Caloosahatchee River
should be moved upstream several miles in order to avoid the salinity problem. The City of Fort
Myers is currently in the process of developing a new water supply source with the intention of
discontinuing use of the Caloosahatchee River.

The Mobil Oil Drilling Program
During the later part of 1966, a geologist from Mobil Oil Corporation, called the U.S.G.S
office in Fort Myers to request some information on the shallow geology of the Southwest Florida
area. A meeting was initiated between a team of Mobil geologists and Durward Boggess to dis-
cuss a proposed confidential test drilling program that Mobil Oil intended to initiate in Southwest
Florida. Mobil was actively involved in a petroleum exploration program in Southwest Florida at
that time. There was some suggestion that the structure of the top of the middle Miocene and
the top of the Eocene sediments in the region could give significant clues with regard to where
to drill in the 12,000 foot zone of the late Cretaceous Sunniland Formation, which was the oil pro-
duction horizon in the area. Durward Boggess and Mobil Oil struck a deal that proved to be the
key factor in the development of an extensive hydrogeologic data base in Southwest Florida.
Mobil decided to drill several hundred test holes to depths ranging from 200 to 1500 feet through-
out Southwest Florida. Drill cuttings would be collected from each well, geologist logs would be
made, and geophysical logs (electric and gamma ray) would be run on each test well. The deal
was that if Durward Boggess agreed to help obtain permission to drill the test wells in road right-
of-ways and assisted in the data collection, he would be given copies of all raw data and geo-
physical logs as long as he agreed not to make the information public for two years (shallow mid-
dle Miocene wells) or five years (upper Eocene wells). Despite being a one man office with sig-
nificant responsibilities and some internal problems with U.S.G.S. policy, the agreement was
made. For over a year, geological data were collected and even water quality information was
obtained. This information formed the hydrogeological data base that allowed Durward Boggess
to define and name the primary freshwater aquifers in Lee County and to suggest where future
water supplies could be obtained (Sproul, Boggess, and Woodard, 1972; Boggess, Missimer,
and O'Donnell, 1977).

FLORIDA GEOLOGICAL SURVEY

The Cape Coral Canal System Salinity Barrier Issue
In the late 1960's and early 1970's, a new urban area in western Lee County, Cape Coral,
was being developed. Gulf American Land Corporation was in the process of digging hundreds
of lineal miles of canals at depths near or below sea level to both obtain fill material to increase
the altitude of the land for flood control and septic tank function and to allow boat access.
In the northwestern part of the development area (north of S.R. 78), the state and local regula-
tory bodies were concerned about the potential for saltwater intrusion into the interior of the area
(Figure 1). Durward Boggess was requested to assess the situation and assist both the regula-
tory agencies and the developer to decide where to control the potential landward movement of
tidal surface-water (saltwater intrusion) through the canal system. After extensive discussion,
Durward Boggess recommended that Burnt Store Road be designated as the salinity control line.
A series of four control structures were constructed along this north-south oriented road. This
was the first concerted effort in Lee County to control the intrusion of tidal saline-water into inte-
rior areas. The precedent set by this decision set the trend for future development throughout
Southwest Florida.

Contamination of the Fresh Groundwater Resources with Artesian Saline-Water
When Durward Boggess arrived in Southwest Florida, all of the water wells in the region
were constructed by the cable-tool method using as little casing as possible. Many of the wells
tapped deep aquifers, under artesian pressure, that yielded saline water. These deep wells were
used for irrigation of crops and for frost protection to some degree. Boggess recognized that
these wells were problematical allowing the entry of saline water into the freshwater aquifers of
Southwest Florida. An earlier study by Klein, Schroeder, and Lichtler (1962) in Hendry County
had documented this problem, and Boggess (1968) first discussed the significance of the prob-
lem in Lee County.
The issue of improper well construction and the adverse effects on groundwater quality was
studied by Boggess for his entire career in Southwest Florida. He demonstrated that if a deep
well was properly plugged, the contamination caused by the discharge of saline-water into the
water-table aquifer was rapidly attenuated by dilution with rainfall (Boggess, 1973). Saline-water
intrusion into confined freshwater aquifers, such as the Sandstone Aquifer in eastern Lee County
or the Mid-Hawthorn Aquifer in western Lee County proved to be a nearly permanent situation
with very slow flushing and dilution (Sproul, Boggess, and Woodard, 1972; Boggess, Missimer,
and O'Donnell, 1977). Boggess recognized that the deep aquifer intrusion of saline-water into
the shallower fresh-water aquifers was not the only problem related to well construction (Figure
2). In Cape Coral, thousands of irrigation and single-family home supply wells were tapping the
Mid-Hawthorn Aquifer. The potentiometric surface of the aquifer was drawn down far below sea
level. Most of the small-diameter irrigation wells that were constructed into the Mid-Hawthorn
Aquifer had steel casings driven by the cable-tool drilling method and contained no cement grout.
Within a few years after construction, corrosion holes formed in the casing at near sea level
cathodicc corrosion). The saline-water occurring within the water-table aquifer adjacent to tidal
canals began to drain into the Mid-Hawthorn Aquifer via gravity feed. This problem virtually
destroyed a large part of the Mid-Hawthorn Aquifer in Cape Coral (Boggess, Missimer and
O'Donnell, 1977).
The research performed by Durward Boggess on the effects of improper well construction
on the fresh groundwater resources lead to the development of new well construction permitting
ordinances imposed by the Lee County government, the South Florida Water Management
District, and years later by the City of Cape Coral. Boggess helped initiate a well plugging pro-
gram to eliminate thousands of wells causing groundwater contamination.

SPECIAL PUBLICATION NO. 49

WELL A
CONTROL VALVE CLOSED
HOLES IN CASING NEAR
LAND SURFACE

WELL B

WELL C

CONTROL VALVE OPEN CONTROL VALVE CLOSED
OR NO VALVE

- WELL CASING -

WELL CASING -

I I

I 1< OPEN BORE
I HOLE
2 (NO CASING)
I I
I I

I I
I I

ARROWS DENOTE
DIRECTION OF
SALINE WATER
I I MOVEMENT

LAND SURFACE
WATER-TABLE AQUIFER
(FRESH WATER)

CONFINING BED
CEMENT GROUT

UPPER PART OF THE
HAWTHORN FORMATION
OR
TAMIAMI FORMATION
(FRESH WATER)

CONFINING BED

LOWER HAWTHORN SUWANEE
OR
DEEPER AQUIFER
UNDER PRESSURE
(SALINE WATER)

Figure 2. Diagram showing how saline-water contaminates freshwater aquifers by improper well
construction or improper management. Well A has corrosion holes in the upper part of the cas-
ing and is not cased to the top of the aquifer containing pressurized saline water. Saline water
migrates into both the confined and unconfined fresh-water aquifers. Well B also is not cased to
the top of the pressurized saline-water aquifer and the wellhead value is either open or broken
off. Saline-water enters all freshwater aquifers via the well or at land surface. Well C is a proper-
ly constructed well with the proper depth of casing and cement grout in the annulus. No saline
water contamination occurs in this well.

Aquifers of Lee County Defined and Named
Little was known about the aquifer system beneath Lee County in 1966. On the Florida East
Coast, the aquifer system was rather simple with the unconfined aquifer in the southeast area
being termed the Biscayne Aquifer and the deep aquifer system being the Floridan Aquifer
(Parker et al., 1955). Boggess recognized that the aquifer system in Lee County was much more
complex than the Florida East Coast with a larger number of aquifers occurring with different
pressures and water qualities. Boggess began to use formal names for the aquifers in order to
communicate with the public in 1970. He was aware that the Floridan Aquifer beneath Lee
County contained numerous individual flow zones. The uppermost two zones that were used for
irrigation and contained slightly saline water, he named in ascending order, the Suwannee
Aquifer and the Lower Hawthorn Aquifer (Figure 3). Two confined aquifers contained freshwa-
ter over large areas of the county. In western Lee County he named the confined freshwater
aquifer the Upper Hawthorn Aquifer (now termed the Mid-Hawthorn Aquifer) and in eastern and
southern Lee County he named the confined freshwater aquifer the Sandstone Aquifer. Boggess

0h
f 7/ h\

I

I

FLORIDA GEOLOGICAL SURVEY

also recognized that another confined freshwater aquifer occurred in the southern part of Lee
County in the Bonita Springs area, which was later termed the Lower Tamiami Aquifer (Figure 3).
There was considerable scientific importance in defining and naming these aquifers. Water
level and quality information could be organized into a consistent scheme using the definitions.
In subsequent years, the aquifer data were used to locate large public supply wellfields and to
develop regional water supply plans.
The definition and naming of the aquifers in Lee County also served an even more impor-
tant function. It allowed the public and press to understand the groundwater system to a greater
degree, which lead to better planning and political decisions on protection and management of
the groundwater resources.

Contamination Caused by Cut and Fill Municipal Landfills
In the 1960's and 1970's, the "state of the art" sanitary landfill design in Florida was the cut
and fill type. In this type of landfill, a series of trenches were dug from land surface into the sur-
ficial aquifer to depths ranging from 8 to 20 feet below surface. A typical "cell" averaged about
15 feet in depth and was up to about 1000 feet in length. Water was removed from the trench
during construction and filling via dewatering. No liners or other methods were used to separate
the municipal waste buried in the cell from the surrounding groundwater. Upon completion of fill-
ing with waste, the trench was covered and another trench was constructed beside it.

The City of Fort Myers operated a cut and fill landfill east of town along Buckingham Road
(Figure 1). The city established a groundwater quality monitoring program around the landfill to
assess any impacts to the groundwater system and at the same time requested the U. S.
Geological Survey to assist in the location of a new landfill site. In 1974, Durward Boggess
informed the City of Fort Myers that the landfill was having an adverse impact on the shallow
groundwater system adjacent to the landfill and on some surface-water bodies that drained into
the headwaters of the Six-Mile Cypress. A report was delivered to the city in 1975 to document
the findings (Boggess, 1975). Ultimately, the city consolidated its efforts to locate a new landfill
site with the Lee County Government and a site was chosen south of State Road 82 (Gulf Coast
Landfill). It should be noted that Durward Boggess advised the Lee County Government that the
site chosen was not ideal for a landfill location, but the county had no other options at the time
because of timing and public protests.

The study of the City of Fort Myers landfill as well as others in South Florida lead to major rule
revisions by the Florida Department of Environmental Regulation (now Florida Department of
Environmental Protection). Cut and fill landfills were outlawed and all landfills ultimately were
required to be lined with impervious material to prevent groundwater contamination. Durward
Boggess was one of the first hydrologists to point out the problem to the local and state govern-
ment officials.

Saline-Water Intrusion into the Shallow Freshwater System of Sanibel Island, Florida
For many years Sanibel Island was a sparsely populated barrier island lying southwest of
Fort Myers. It was connected to the mainland by a ferryboat that took residents and day-trippers
to and from the island. In 1965, a bridge was completed to the island and activity greatly
increased. A building boom began on the island in the early 1970's with a number of deep canals
and artificial lakes being constructed. The shallow aquifer system on Sanibel Island contained
a fragile freshwater lense that was critical to the maintenance of an internal freshwater marsh
and the island vegetation. The construction activity was causing the intrusion of saltwater into
the shallow aquifer system and was destroying the freshwater lense.

SPECIAL PUBLICATION NO. 49

Figure 3. The original aquifer terminology for Lee County as named by Durward Boggess (modi-
fied from Sproul, Boggess & Woodard, 1972).

FLORIDA GEOLOGICAL SURVEY

Durward Boggess was asked to study the problem and conducted an investigation of the
shallow water resources over a period of several years in the early 1970's (Boggess, 1974). The
information obtained from this investigation was used to develop new construction standards for
Sanibel Island and ultimately the information was used to help develop the comprehensive land
use plan for the island (after the incorporation of the City of Sanibel).

Wetland Destruction in Lehigh Acres Caused by Over-Drainage
The development of a vast tract of land in eastern Lee County was very active in the late
1960's and early 1970's. Lehigh Acres was being carved out of pristine pine flatwoods and fresh-
water wetland areas. The area was flat and poorly drained, so a network of deep drainage
canals was being constructed to drain the area to the north via the Orange River, Bedman Creek,
and other streams to the Caloosahatchee River. Over a short period of time, a major wetland
feature in the area, Halfway Pond, dried up and was lost. There was considerable public out-
rage over the destruction of this 400-acre pond and a number of state, federal, and local agen-
cies took interest in the issue.
Durward Boggess was requested to make a rapid investigation of the area to provide a
hydrogeologic assessment of the effects of drainage on the groundwater system (Boggess and
Missimer, 1975). The report on the area was used by federal agencies to stop the over-drainage
of the wetlands and the water management district required that water level control structures be
placed in the drainage canals to retain groundwater.

Saline Water as a Future Water Supply for Lee County
Beginning in the late 1960's, Durward Boggess took a strong interest in the artesian, saline
water resources of Lee County. First, he recognized that the deep, free-flowing wells were a
source of contamination to the freshwater aquifers. However, as he studied the aquifers, he real-
ized that these waters were also resources that could be treated using new water treatment tech-
nology. This realization was confirmed, when he was requested by the Island Water Association
of Sanibel Island to help assist in the development of a public water supply system on the island.
In the past, only shallow wells and cisterns were used for water supply on the island, but with
rapid development, the shallow aquifer was not capable of yielding the necessary quantity of
water required. The Island Water Association decided to use deep wells tapping the Lower
Hawthorn Aquifer System to feed a new desalination system that used the electrodialysis
process to desalt the water. Boggess provided considerable hydrogeologic data and expertise
to develop the first saline-water wellfield in the Lee County (Boggess, 1974b; 1974b; Boggess
and O'Donnell, 1982).
Over a period of several years, Boggess accumulated a large data base on the saline water
resources of Lee County. In 1974, he published a critical document that provided the key hydro-
geologic and water quality information to allow the successful development of those resources
(Boggess, 1974). In the mid-1970's, Cape Coral and Pine Island developed wellfields to use the
saline water resources, using the initial data base and forethought of Durward Boggess.

The Water-Table and Sandstone Aquifers of Eastern and Southeastern
Lee County as Future Water Supplies
In his investigations of Lee County, Durward Boggess realized in the early 1970's that the
county could be divided into the water poor western and northern area and the water rich east-
ern and southern area. From the geologic data base obtained from the Mobil Oil test drilling pro-
gram and from extensive inventorying of existing wells, Boggess believed that the shallow and
immediate aquifers in eastern and southern Lee County would be the only viable freshwater
resources that could be developed in the future. During the later part of his career, he concen-

SPECIAL PUBLICATION NO. 49

treated on compiling the hydrogeologic investigation in this area (Boggess, Missimer and
O'Donnell, 1982; Boggess and Watkins, 1986). The information gathered by Boggess in east-
ern and southern Lee County was instrumental in the successful development of the Lehigh
Acres Utilities Wellfield (Sandstone Aquifer), the Florida Cities Green Meadows Wellfield (water-
table and Sandstone aquifers), the Lee County South Wellfield (water-table and Sandstone
aquifers), the Gulf Utilities north and south wellfields (water-table aquifer), and the Bonita Springs
Utilities west and east wellfields (Lower Tamiami Aquifer).

The Well Schedule and Well Log Data Base
Over his 13 years with the U. S. Geological Survey in Lee County, Durward Boggess was
meticulous about the compilation of a well and geologic data base. He used topographic maps
of the entire county to locate every well on which he could obtain data. The well was given a
number and the data were recorded in a series of well schedules. When a geologic log existed,
it was given a corresponding number and was recorded in a file. The same was true for water
quality analyses. It was a time-consuming and tedious job to establish and maintain this record-
keeping system, but it was critical in developing an accurate and detailed assessment of the
groundwater resource. Data were collected on over 4000 wells in Lee County during the
Boggess years. This is the most extensive hydrogeologic data base established for any county
in the state of Florida and the credit for it goes to Durward Boggess.

Durward H. Boggess, The Man
Durward Boggess left a reputation as a man of impeccable integrity, who could always be
relied upon to give fair and unbiased technical council. He never turned down any information
request and talked to anyone who contacted the U. S. Geological Survey office. He established
an excellent rapport with the press and helped educate numerous, young reporters. He talked
with and provided information to elected officials, but he was never political, in the sense of pur-
suing some personal agenda. He was particularly skilled at finding solutions to the acquisition
of technical data in the field, such as how to keep old, worn-out recording devices working, or
how to collect flood stage data at minimal cost (crest-stage gages), or how to collect water sam-
ples at depths without expensive devices. He was also skilled at teaching water resources data
collection methods to young geologists and to old engineers without ruffling sensitive egos.
Durward Boggess never had said anything derogatory about any person, even when he was crit-
icized. In his quiet, gentle way, he was able to obtain the funding he needed to perform scien-
tific investigations of the highest quality without resorting to crisis creation via the media.

CONCLUSIONS

The contributions of Durward Boggess to the knowledge on the hydrology and geology of
Lee County is a case study on how one man with integrity and spirit can make a profound con-
tribution to science. The methods Mr. Boggess employed to glean the most information possi-
ble with minimal budgets is a case study for all practicing hydrologists and hydrogeologists.
Without the development of the data base and the forethought given by Durward Boggess, the
water resources of Lee County would have been severely damaged two decades ago. These
contributions are still being used today as the population growth of Lee County causes further
development of the water resources. Every citizen of Southwest Florida owes a debt of gratitude
to Durward Boggess for his diligence and perseverance in working on the hydrology and geolo-
gy of Lee County, Florida.

FLORIDA GEOLOGICAL SURVEY

REFERENCES

Dall, W. H., 1890-1903, Contributions to the Tertiary fauna of Florida with special reference to the
Miocene Silex beds of Tampa and the Pliocene beds of the Caloosahatchee River: Wagner
Free Institute Science Trans., v. 3, 6 parts, 1654 pp.

DuBar, J. R., 1958, Stratigraphy and paleontology of the late Neogene strata of the
Caloosahatchee River area of southern Florida: Florida Geological Survey Bulletin No. 40,
267 pp.

DuBar, J. R., 1962, Neogene biostratigraphy of the Charlotte area in Southwestern Florida:
Florida Geological Survey Bulletin No. 43, 83 pp.

Heilprin, A., 1887, Explorations on the West Coast of Florida and in the Okeechobee Wilderness:
Wagner Free Institute of Philadelphia, 134 pp.

Kenner, W. E., and Brown, E., 1956, Surface water resources and quality of waters in Lee
County, Florida: Florida Geological Survey Information Circular No. 7, 69 pp.

Klein, H., Schroeder, M. C., and Lichtler, W. F., 1964, Geology and groundwater resources of
Glades and Hendry counties, Florida: Florida Geological Survey Rept. of Investigations No.
37, 101 pp.

Olsson, A. A., and Harbison, A., 1953, Pliocene Mollusca of Southern Florida: Academy of
Natural Science, Philadelphia, Mon. 8, 457 pp.

Parker, G. G., and Cooke, C. W, 1944, Late Cenozoic geology of southern Florida with a dis-
cussion of the ground water: Florida Geological Survey Geological Bulletin No. 27, 119 pp.

Parker, G. G., Ferguson, G. E., and Love, S. K., 1955, Water resources of southeastern Florida:
U. S. Geological Survey Water-Supply Paper 1255, 965 pp.

Tucker, H. I., and Wilson, D., 1932-1933, Some new and otherwise interesting fossils from the
Florida Tertiary: Bull. Am. Paleontology, v. 18, p. 39-82.

COMPLETE PUBLICATIONS LIST OF DURWARD H. BOGGESS

Lee County:

Boggess, D. H., 1968, Water-supply problems in southwest Florida:U.S. Geological Survey
Open-File Report FL-68003, 27 p.

Boggess, D. H., 1970, A test of flushing procedures to control salt-water intrusion at the W.F.
Franklin Dam near Fort Myers, Florida: Florida Bureau of Geology Information Circular 62.
pt 1, p. 1-15.

Boggess, D. H., 1970, The magnitude and extent of salt-water contamination in the
Caloosahatchee River between La Belle and Olga, Florida: Florida Bureau of Geology
Information Circular 62, pt. 2, p. 17-39.

SPECIAL PUBLICATION NO. 49

Boggess, D. H., 1972, Controlled discharge form the W.P. Franklin Dam as a means of flushing
saline water from the fresh-water reach of the Caloosahatchee River, Lee County, Florida:
U.S. Geological Survey Open-File Report FL-72028, 45 p.

Boggess, D. H., 1973, The effects of plugging a deep artesian well on the concentration of
chloride in water in the water-table aquifer at Highland Estates, Lee County, Florida:
U.S. Geological Survey-Open File Report FL73003, 20 p.

Boggess, D. H. 1974, Saline ground-water resources of Lee County, Florida: U.S. Geological
Survey Open-File Report 74-247, 62 p.

Boggess, D. H., 1974, The shallow fresh-water system of Sanibel Island, Lee County, Florida,
with emphasis on the sources and effects of saline water: Florida Bureau of Geology Report
of Investigations 69, 52 p.

Boggess, D.H., 1975, Effects of a landfill on ground-water quality: U.S. Geological Survey Open-
File Report 75-594, 44 p.

Boggess, D. H., and Missimer, T. M., 1975, A reconnaissance of hydrogeologic conditions in
Lehigh Acres and adjacent Lee County, Florida: U.S. Geological Survey Open-File 75-55,
106 p.

Boggess, D. H.,, Missimer, T. M., and O=Donnell, T. H., 1977, Saline-water intrusion related to
well construction in Lee County, Florida: U.S. Geological Survey Water-Resources
Investigations 77-33, 29 p.

Boggess, D. H., Missimer, T. M. and O=Donnell, T. H., 1981, Hydrogeologic sections through Lee
County, and adjacent areas of Hendry and Collier counties, Florida: U. S. Geological Survey
Water-Resources Investigations Open-File Report 81-639, 1 sheet.

Boggess, D. H., and O=Donnell, T.H., 1982, Deep artesian aquifers of Sanibel and Captiva
Islands, Lee County, Florida: U. S. Geological Survey Open-File Report 82-253, 32 p.

Boggess, D. H., and Watkins, F. A., Jr., 1986, Surficial aquifer system in eastern Lee County,
Florida: U. S. Geological Survey Water-Resources Investigations 85-4161, 59 p.

Fitzpatrick, D. J., Boggess, D. H., Missimer, T. M., and O=Donnell, T. H., 1979, Saltwater intru-
sion in the City of Cape Coral: U. S. Geological; Survey Professional Paper 1150, p. 114-
115.

Missimer, T. M., and Boggess, D. H., 1974, Fluctuations of the water table in Lee County, Florida,
1969-1973: U. S. Geological Survey Open-File Report FL-74019, 41 p.

Sproul, C. R., Boggess, D. H., and Woodard, H. J., 1972, Saline-water intrusion from deep arte-
sian sources in the McGregor Isles areas of Lee County, Florida: Florida Bureau of Geology
Information Circular 75, 30 p.

FLORIDA GEOLOGICAL SURVEY

Other:

Adams, J. K., and Boggess, D. H., 1963, Water-table, surface-drainage, and engineering soils
map of the Saint Georges area, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-60.

Adams, J. K., and Boggess, D. H., 1964, Water-table, surface-drainage, and engineering soils
map of the Wilmington area, Delaware: U.S. Geological Survey Hydrologic Investigations
Atlas, HA-79.

Adams, J. K., and Boggess, D. H., 1964, Water-table, surface-drainage, and engineering soils
map of the Taylors Bridge area, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-80.

Adams, J. K., and Boggess, D. H., 1964, Water-table, surface-drainage, and engineering soils
map of the Sharptown area, Delaware: U. S. Geological Survey Hydrologic Investigations
Atlas, HA-84.

Adams, J. K., and Boggess, D. H, 1964, Water-table, surface-drainage, and engineering soils
map of the Hickman area, Delaware: U. S. Geological Survey Hydrologic Investigations
Atlas, HA-100.

Adams, J. K., and Boggess, D. H., 1964, Water-table, surface-drainage, and engineering soils
map of the Ellendale Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-101.

Adams, J. K., and Boggess, D. H., 1964, Water-table, surface-drainage, and engineering soils
map of the Harbeson Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-108.

Adams, J. K., and Boggess, D. H., 1964, Water-table, surface-drainage, and engineering soils
map of the Trap Pond area, Delaware: U. S. Geological Survey Hydrologic Investigations
Atlas, HA-120.

Adams, J. K., Boggess, D. H., and Coskery, 0. J., 1964, Water-table, surface-drainage, and
engineering soils map of the Clayton area, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-83.

Adams, J. K., Boggess, D. H., and Coskery, 0. J., 1964, Water-table, surface-drainage, and
engineering soils map of the Seaford East Quadrangle, Delaware: U. S. Geological Survey
Hydrologic Investigations Atlas, HA-106.

Adams, J. K., Boggess, D. H., and Coskery, 0. J., 1964, Water-table, surface-drainage, and
engineering soils map of the Frankford area, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-119.

Adams, J. K., Boggess, D. H., and Davis, C. F., 1964, Water-table, surface-drainage, and engi-
neering soils map of the Dover Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-139.

SPECIAL PUBLICATION NO. 49

Adams, J. K., Boggess, D. H., and Davis, C. F., 1964, Water-table, surface-drainage, and engi-
neering soils map of the Lewes area, Delaware, U. S. Geological Survey Hydrologic
Investigations Atlas, HA-103.

Boggess, D. H., and Adams, J. D., 1963, Water-table, surface-drainage, and engineering soils
map of the Neward area, Delaware: U. S. Geological Survey Hydrologic Investigations
Atlas, HA-64.

Boggess, D. H., and Adams, J. K., 1964, Water-table, surface-drainage, and engineering soils
map of the Middletown area, Delaware: U. S. Geological Survey Hydrologic Investigations
Atlas, HA-82.

Boggess, D. H., and Adams, J. K, 1964, Water-table, surface-drainage, and engineering soils
map of the Greenwood Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-99.

Boggess, D. H., and Adams, J. K., 1964, Water-table, surface-drainage, and engineering soils
map of the Seaford West area, Delaware: U. S. Geological Survey, Hydrologic
Investigations Atlas, HA-105.

Boggess, D. H., and Adams, J. K., 1964, Water-table, surface-drainage, and engineering soils
map of the Bethany Beach area, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-122.

Boggess, D. H., and Adams, J. K., 1964, Water-table, surface-drainage, and engineering soils
map of the Laurel area, Delaware: U. S. Geological Survey Hydrologic Investigations Atlas,
HA-123.

Boggess, D. H., and Adams, J. K., 1965, Water-table, surface-drainage, and engineering soils
map of the Millsboro area, Delaware: U. S. Geological Survey Hydrologic Investigations
Atlas, HA-121.

Boggess, D. H., and Adams, J. K., 1965, Water-table, surface-drainage, and engineering soils
map of the Little Creek Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-134.

Boggess, D. H., and Adams, J. K., 1965, Water-table, surface-drainage, and engineering soils
map of the Kenton area, Delaware: U. S. Geological Survey Hydrologic Investigations Atlas,
HA-138.

Boggess, D. H., Adams, J. K., and Coskery, 0. J., 1964, Water-table, surface-drainage, and engi-
neering soils map of the Milton Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-102.

Boggess, D. H., Adams, J. K., and Davis, C. F., 1964, Water-table, surface-drainage and engi-
neering soils map of the Smyrna area, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-81.

FLORIDA GEOLOGICAL SURVEY

Boggess, D. H., Adams, J. K., and Davis, C. F., 1964, Water-table, surface-drainage, and engi-
neering soils map of the Georgetown Quadrangle, Delaware: U. S. Geological Survey
Hydrologic Investigations Atlas, HA-107.

Boggess, D. H., Adams, J. K., and Davis, C. F., 1964, Water-table, surface-drainage, and engi-
neering soils map of the Rehoboth Beach area, Delaware: U. S. Geological Survey
Hydrologic Investigations Atlas, HA-109.

Boggess, D. H., Davis, C. F., and Coskery, 0. J., 1965, Water-table, surface-drainage, and engi-
neering soils map of the Milford Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-133.

Boggess, D. H., Davis, C. F., and Coskery, 0. J., 1965, Water-table, surface-drainage, and engi-
neering soils map of the Burrsville area, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-135.

Boggess, D. H., Davis, C. F., and Coskery, 0. J., 1965, Water-table, surface-drainage, and engi-
neering soils map of the Wyoming Quadrangle, Delaware: U. S. Geological Survey
Hydrologic Investigations Atlas, HA-141.

Boggess, D. H., and Heidel, S. G., 1968, Water resources of the Salisbury area, Maryland:
Maryland Geological Survey Reports of Investigations 3, 69 p.

Boggess, D. H., and Rima, D. R., 1962, Experiments in water spreading at Newark,
Delaware, U. S. Geological Survey Water-Supply Paper 1594-B, p. B1-B15.

Davis, C. F., and Boggess, D. H., 1964, Water-table, surface-drainage, and engineering soils
map of the Maryland area, Delaware: U. S. Geological Survey Hydrologic Investigations
Atlas, HA-132.

Davis, C. F., and Boggess, D. H., 1964, Water-table, Surface-drainage, and engineering soils
map of the Harrington Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-136.

Davis, C. F., and Boggess, D. H., 1964, Water-table, surface-drainage, and engineering soils
map of the Mispillion River Quadrangle, Delaware: U. S. Geological Survey Hydrologic
Investigations Atlas, HA-137.

Davis, C. F., Boggess, D. H., and Coskery, 0. J., 1965, Water-table, surface drainage, and engi-
neering soils map of the Frederica area, Delaware: U.S. Geological Survey Hydrologic
Investigations Atlas, HA-140.

SPECIAL PUBLICATION NO. 49

FLORIDA GEOLOGICAL SURVEY

The Surficial Geology of Lee County and the Caloosahatchee Basin

Thomas M. Scott
Florida Geological Survey, 903 W. Tennessee St., Tallahassee, FL 32304-7700
And
Thomas M. Missimer
Missimer International, Inc., 8140 College Parkway, Suite 202, Fort Myers, FL 33919

ABSTRACT

Knowledge of the surficial geology is a processor to developing an understanding of the
regional hydrogeology. Surficial geologic mapping in Florida is problematic because of the low
relief and sand cover. The mapping effort in Lee County relied heavily on data from well cuttings
and cores due to the sparse occurrence of pits, quarries and natural outcrops. The authors have
spent many years visiting pits and quarries and working subsurface samples to develop an
understanding of the regional geologic framework. The accumulated database was utilized to
determine sand overburden thickness and the underlying stratigraphic units for creating the Lee
County geological map.
The geologic units mapped were the Tertiary Tamiami Formation (Tt), Tertiary-Quaternary
shell units (Tqsu includes Caloosahatchee, Bermont, and Fort Thompson Formations of previ-
ous usage) and Quaternary (Holocene) coastal and estuarine sediments (Qh). Less than 20 feet
of undifferentiated sands occurred within the map area.

INTRODUCTION

Geological maps provide an important tool for developing an understanding of geological
history and natural resources. Knowledge of the regional surficial and near-surface geology is a
necessary prerequisite to beginning to understand hydrogeology. The type and distribution of
surficial and near-surface sediments has a direct bearing on the occurrence of surface water and
the recharge of groundwater.
Vernon and Puri (1964) produced the last geological map by the Florida Geological Survey
(FGS). Brooks (1982) published an independent version of the State geological map. Both
maps required updating and revision. In the late 1980s, the FGS began an effort to create an
updated and revised State geological map. In 1991, the mapping program focus changed toward
the development of county geological maps for a statewide radon hazard analysis investigation.
The maps created for this investigation formed the basis for the new State geological map.
Florida is the only state in the United States that lies entirely within a coastal plain province.
With the highest elevation in the State of just 345 feet, relief is generally limited and few outcrops
exist. The low relief of the southwestern Florida landscape yields little information to geologists
from natural exposures making geological mapping problematic. As a result, the mapping effort
in Lee County and the Caloosahatchee Basin utilized information gathered from well cuttings and
cores (including a number of cores drilled by the FGS), quarries and pits, and limited natural out-
crops. In developing a concept of the regional geologic framework, the authors have spent many
years examining exposed sections and spoil piles in pits and quarries in addition to analyzing
subsurface samples. The accumulated database was utilized in formulating the Lee County geo-
logic map (Figure 1).
Much of the Florida landscape is covered by a sand blanket of varying thickness. Mapping
the general surficial occurrence of the sands provides only limited information. As such, the con-

SPECIAL PUBLICATION NO. 49

vention was adopted of removing up to 20 feet of undifferentiated sands and mapping the under-
lying formations. In areas where the sand cover exceeded 20 feet in thickness, the occurrence
of sand was mapped. Within Lee County, no areas of more than 20 feet of undifferentiated sand
were identified. However, due to the nature of the database, sands thicker than 20 feet may
occur locally within the county.

GEOLOGY

The geologic units mapped in Lee County were the Tertiary Tamiami Formation (Tt), Tertiary-
Quaternary shell units (Qsu includes Caloosahatchee, Bermont and Fort Thompson formations
of previous usage) and Quaternary (Holocene) coastal and estuarine sediments (Qh).
The oldest formation shown on the Lee County geological map is the Pliocene Tamiami
Formation (Tt). The Tamiami Formation is a poorly defined lithostratigraphic unit containing a
wide range of mixed carbonate-siliciclastic lithologies and associated faunas (Missimer, 1992).
The Peace River Formation, Hawthorn Group, underlies the Tamiami Formation throughout the
county. The Tamiami Formation consists a mixture of variably sandy limestone, sands, and clays
containing varying percentages of phosphate grains. Fossils, including mollusks, echinoids and
corals, are commonly abundant in the Tamiami Formation. Fossil preservation varies from well
preserved to molds and casts of the original fossils.
Overlying the Tamiami Formation throughout much of Lee County are sediments mapped as
undifferentiated Tertiary/Quaternary (Plio-Pleistocene) shell-bearing units (Qsu). The
Caloosahatchee, Bermont and Fort Thompson formations of previous references are included
within the Qsu designation due to the primarily biostratigraphic nature of the units throughout
their areal extent (see Scott, 1992). Within portions of the map area, the Caloosahatchee and
Fort Thompson are lithologically separable. However, throughout much of the rest of southern
Florida, the units are lithologically indistinct. This unit consists of sand with subordinate lime-
stone and clay. Fossils, including mollusks and corals, are common, often abundant and preser-
vation is often excellent.
A quartz sand blanket (less than 20 feet thick) overlies Tt and Qsu throughout the county.
The sand is generally a fine to medium well sorted sand with no fossils. Along the coast, below
an altitude of approximately 5 feet msl, are sediments mapped as Holocene age sediments.
These sediments consist of quartz sand with a variable organic component and occasional peat
to muck deposits. The Holocene sediments include the beach ridge and dune sands.

REFERENCES

Brooks, H.K., 1982, Geologic Map of Florida: Center for Environmental and Natural Resources,
University of Florida.

Missimer, T.M., 1992, Stratigraphic relationships of sediment facies within the Tamiami Formation
of southwestern Florida: Proposed intraformational correlations; in Scott, T.M., and Allmon,
W.D., editors, The Plio-Pleistocene stratigraphy and Paleontology of southern Florida;
Florida Geological Survey Special Publication 36, p.63-92.

Scott, T. M., 1992, Coastal Plains stratigraphy: The dichotomy of biostratigraphy and lithos-
tratigraphy A philosophical approach to an old problem: in Scott, T.M., and Allmon, W. D.,
The Plio-Pleistocene stratigraphy and paleontology of southern Florida: Florida Geological
Survey Special Publication 36, p. 21-26.

Figure 1. Geologic Map of Lee County, Florida.

SPECIAL PUBLICATION NO. 49

T. Missimer and T. Scott, 1993, Geologic map of Lee County, Florida: Florida Geological Survey
Open File Map Series no. 61.

Vernon, R.O., and Puri, H.S., 1964 Geologic map of Florida, Florida Bureau of Geology Map
Series 18.

FLORIDA GEOLOGICAL SURVEY

LATE NEOGENE GEOLOGY OF NORTHWESTERN
LEE COUNTY, FLORIDA

Thomas M. Missimer
CDM/Missimer International, Inc., 8140 College Parkway, Suite 202, Fort Myers, Florida 33919

ABSTRACT

During the past 24 years, the Neogene geology of northwestern Lee County has been stud-
ied in numerous dewatered, shell pits. The thickness of the stratigraphic section studied is about
30 feet and contains three formations; the Tamiami, the Caloosahatchee, and the Fort
Thompson. The Tamiami Formation is a predominantly siliciclastic unit, equivalent to the Sand
Facies of Missimer (1992) with one occurrence of the Pinecrest Member (predominantly arago-
nitic mollusk shell) atAcline (Charlotte County). The Caloosahatchee Formation is a mixed car-
bonate and siliciclastic unit that is divided into three separate units by two intraformational uncon-
formities. The Fort Thompson Formation is a shell and quartz sand unit that contains two or
three stratigraphic units. From the base to the top of the formation, the relative percentage of
quartz sand increases from about 20 to 100% by volume.
The lithostratigraphy of the shallow Neogene sediments adjacent to Charlotte Harbor shows
that numerous transgressive and regressive sea level events produced a series of depositional
environment changes over the last 4 million years. The region was blanketed with a sheet of
quartz sand similar to the West Florida Shelf of today during the Pliocene as the Tamiami
Formation was deposited. During deposition of the Caloosahatchee Formation, the region was
subtropical with predominantly carbonate deposition and a coastal influx of quartz sand. Tropical
and subtropical mollusks and corals were abundant in the region producing an environment sim-
ilar to the present area between Cape Sable and Florida Bay. Deposition of the Fort Thompson
Formation brought a substantial change to the environment with an evolution to barrier island
and shallow nearshore deposition patterns similar to those observed today.

INTRODUCTION

Geological work in the northwestern area of Lee County and southern area of Charlotte
County began during the 1880's with a few early descriptive works. In his classic work on the
geology of the lower Florida West Coast, Heilprin (1887) wrote "Prior to our visit, the only portion
of the state that had been examined geologically, or on which a geological report had been pre-
pared, was the region lying north of a line running almost due northeast from the Manatee River,
just south of Tampa Bay, to the east coast. Below this all was conjectural, although the exis-
tence of certain limestones of undetermined age was hinted at, or even located, by a number or
causal observers (Tuomey, Conrad) who chanced to navigate some of the outer waters. Such
a limestone was reported by Tuomey to be found in Charlotte Harbor, but the exact locality of its
occurrence is not noted." Another scientist from the Wagner Free Institute of Philadelphia,
William H. Dall, was the first geologist to visit some of the late Neogene exposures in the
Charlotte Harbor area, immediately north of Lee County. Dall (1890-1903) described many of
the fossils found in the Pliocene and Pleistocene sediments of the region. During the 1930's,
several geologists examined exposures of the Caloosahatchee and Fort Thompson formations
at locations near Shell Creek, Alligator Creek, and in spoil piles adjacent to excavations. Wendall
C. Mansfield, Druid Wilson, Helen I. Tucker, and Axel A. Olsson visited several sites and col-
lected fossil mollusks. The paleontology of the fossil mollusks was described in a few publica-
tions (Tucker and Wilson, 1932a; Olsson and Harbison, 1953). In 1958, a shell pit located near

SPECIAL PUBLICATION NO. 49

Acline (Figure 1) was drained to make bed collections of the fossils and to describe the geology.
Druid Wilson of the U.S. Geological Survey and Stanley Olsen of the Florida Geological Survey
made these collections, but no work other than a fauna list (Tucker and Wilson, 1932b; also in
DuBar, 1962) was ever published. A detailed investigation of the Neogene geology of the
Charlotte Harbor area was published by DuBar (1962). DuBar described the geology at 13 sites
located adjacent to Charlotte Harbor and the geology adjacent to Shell Creek.
The geologic descriptions presented in this paper are considered to be preliminary and were
compiled at numerous locations in Lee and Charlotte counties over a period of 24 years by the
author and a number of associates. The author was first introduced to the geology of the
Charlotte Harbor area by F. Sternes McNeill, who was one of W. C. Mansfield's field assistants
in the 1930's. McNeill accompanied Durward Boggess and the author to several locations in the
area between 1972 and 1975.

NEOGENE STRATIGRAPHY

Introduction
A number of shell and sand pits have been excavated adjacent to the southeastern margin
of Charlotte Harbor in Charlotte and Lee counties and in the Cape Coral area of Lee County over
the past 40 years. Many of these excavations were dewatered to facilitate sediment
removal, which allowed detailed descriptions of the sediments to be made. Three Neogene
stratigraphic units were penetrated in most of the excavations, which include the Tamiami,
Caloosahatchee, and the Fort Thompson formations. Neogene time includes the Miocene to the
end of the Pleistocene or 23.8 to 0.01 Ma or a million years before present (Berggren et al.
1995). A general stratigraphic column is shown in Figure 2 using the stratigraphic terminology
of Missimer (1992) for the Tamiami Formation and the terminology of DuBar (1962) for the
Caloosahatchee and Fort Thompson formations. Although geologic information was collected at
each of the locations (sections measured and described) shown in Figure 1, detailed descrip-
tions of the geology are presented for only the Burnt Store Road North Pit (4), the Nelson Road
Pit (5), and the Chiquita Sand Pit (6).

Tamiami Formation
The Tamiami Formation is a Pliocene unit that contains a wide variety of members or facies
dependant upon the specific location studied. Missimer (1992) presented a stratigraphic corre-
lation of the various lithologic units found within the Tamiami Formation in Southwest Florida
(Figure 3). In the northern part of the study area, the exposures of the Tamiami Formation in
Alligator Creek are a sandy, calcareous clay with some phosphate and a few calcitic fossil frag-
ments (DuBar, 1958). The calcareous clay faces correlates to the tan clay and sand faces,
which occurs near the base of the formation (Figure 3). At all other locations, with the exception
of the Acline Pit, the section of the Tamiami Formation penetrated was either a sand and partially
indurated sandstone (Burnt Store Road North Pit), an unlithified quartz sand with solely calcitic
fossils interbedded with some limestone (Nelson Road Pit), or a partially indurated sand and bar-
nacle hash (Chiquita Sand Pit). All of these predominantly quartz sand units correlate lithos-
tratigraphically with the sand faces of Missimer (1992) shown in Figure 3.
The only exposure of the classical Pinecrest Member containing a wide diversity of mollus-
can species with preserved aragonitic shell is at the Acline Pit site. The Pinecrest Member of the
Tamiami Formation is the youngest member of the formation and does not occur as a continu-
ous stratigraphic unit in the area of Charlotte Harbor.

FLORIDA GEOLOGICAL SURVEY

Charlotte
Harbor

Gulfof
MeA'co

Acline Pit
Coral Rock Industries Pit
The Dirt Store Pit
Burnt Store Road Pit
Nelson Road Pit
Chiquita Sand Pit

N

k

SCALE
12 MILES
20 KILOMETERS

Figure 1. Map of Charlotte Harbor area showing the locations of pits studied in Lee and
Charlotte counties.
Caloosahatchee Formation
DuBar (1962) recognized five stratigraphic subdivisions of the Caloosahatchee Formation in
the Charlotte Harbor area (Figure 4). Although these subdivisions of the formation do occur, they
are rarely if ever all present at a single location or in the same stratigraphic position Stratigraphic
sections are commonly described in terms of sequence stratigraphy, in which a sequence is
defined as an unconformity-bounded stratal unit (Van Wagoner et al. 1990). A sequence is sub-
divided into parasequences, which are the building blocks of the sequence. A parasequence is
defined as Arelatively conformable successions of genetically related beds or bedsets bounded

SPECIAL PUBLICATION NO. 49

Age Formation Member

Upper
Fort Thompson Upper
Lower
Pleistocene Lower
F
E

Caloosahatchee
C
B
A
Pliocene
Pinecrest
Tamiami
Sand

Figure 2. General stratigraphic column showing the late Neogene units studied in the Charlotte
Harbor area.
by marine-flooding surfaces or their correlative surfaces@ (Van Wagoner et al. 1990). Based on
modern concepts of sequence stratigraphy, the Caloosahatchee Formation can probably be bro-
ken down into three different sequences or perhaps parasequences when viewed on a regional
basis. There are at least two distinctive breaks in the Caloosahatchee stratigraphic section,
marked by the occurrence of either a laminated crust and disconformity or the occurrence of a
freshwater limestone. These breaks correspond to either marine-flooding surfaces or to terres-
trial discontinuities as in the case of freshwater limestones. In the general stratigraphic column
show in Figure 4, the unconformities dividing the section occur at the top of Units C and E. It is
not possible to correlate regionally individual lithologic units within the formation, because of
spatial variability caused by depositional environment changes. However, the correlation of the
unconformities in stratigraphic order does allow correlation of time lines, which was the method
used by Perkins (1977) for correlating these stratigraphic units along the Florida East Coast.
The Caloosahatchee Formation at the Burnt Store Road North Pit contained four different

2.8

!5

Ld
O 0
4. <

4.2

Figure 3. Diagram showing the correlation of lithostratigraphic unit, defined facies, and formal members of the Tamiami Formation
(from Missimer, 1992).

SPECIAL PUBLICATION NO. 49

WHITE TO
GRAY SAND

YELLOW
TO BROWN
SAND

UNIT

UNIT D

UNIT C
UNIT E
- U NIT

Sand

Sandy marl

Sandy

Sandy marl
-- Conglom.
limestone
Calcareous
clay

Figure 4. General stratigraphic column showing the stratigraphic units studied by DuBar (1962)
in the Charlotte Harbor area with unit descriptions (DuBar, 1962).
lithic units (Figure 5). At this location there are only two stratigraphic breaks in the section
instead of the three found in the DuBar general section. A basal sequence or parasequence con-
tains two lithic units with an unlithified shell and sandy mud at the base and an indurated lime-
stone containing abundant shell at the top. The occurrence of freshwater fossils at the base of
the section could indicate the occurrence of another stratigraphic break, but the remaining sec-
tion does not occur. The uppermost unit consists of a basal, unlithified shell unit overlain by an
indurated limestone containing abundant aragonitic mollusk shells. The top of the limestone con-

UNIT E

* *

* *

FLORIDA GEOLOGICAL SURVEY

0

5

z o

I-
I

a 15

20

Z
0
0.

0
I

L-

U)UJ
85
00
.JI

*-- Sand, white

S -- Sandstone

Shell and sand

Shell
Unconformity
-4 -4--- 4 Limestone, shell
-- Shell

<4- Limestone, shelly

( .- Shell, muddy, sand
Freshwater fossils

Unconformity

<- Sandstone, limestone,
barnacles

*-- Water

Figure 5. Neogene stratigraphy of the Burnt Store Road North Pit in Lee County.
tains a laminated crust at some locations in the pit. Without some absolute time control, it is not
possible to correlate this section with the general DuBar typical section.
To the southeast of Charlotte Harbor, the occurrence of the Caloosahatchee Formation is
limited to only a few locations, because the formation has been removed by erosion or was not
deposited. The southernmost known occurrence of the formation on the Florida West Coast is
at the Nelson Road Pit, but only in the northeast corner of the pit (Figures 6 and 7). Despite the
relatively thin section of the formation at about 8 feet, nine different lithologies were found in
three sequences or parasequences. The basal unit is bounded with a disconformity at the base
and a freshwater limestone at the top. The lowest lithologic unit is an unlithified quartz sand and
shell. An indurated sandy limestone with shell lies conformably above the lowest unit and the
sequence is capped by a freshwater limestone. The middle sequence contains three different
lithologic units beginning at the base with a partially indurated limestone containing well-pre-

SPECIAL PUBLICATION NO. 49

UJ
LL
Z

a-

10

15

20

25

i
Sc

I-

-- Fill
-- Sand
s-- Sandstone

Sand and shell

Shell and sand

- Unconformity

Limestone
and shell

- Unconformity

- Unconformity

__ Muddy sand
and sandstone

Figure 6. Neogene stratigraphy of the Nelson Road Pit located in Lee County.
served aragonitic mollusk shells. This lithic unit is underlain by a coralline boundstone, contain-
ing about ten different species of corals. The sequence is capped by a highly altered limestone
containing predominantly sparite and no preserved aragonitic fossils. The top of the limestone
contains some solution depressions partially infilled with indurated laminated muds. The upper-
most sequence also contains three different lithologies. The base is an unlithified quartz sand

FLORIDA GEOLOGICAL SURVEY

Unconformity
S _Freshwater
13 .limestone

Limestone,
S r hard, indurated

15 Sand and shell

wI- Discontinuity
LI Limestone,
Ssparite
17 r .. .* Coralline
I" boundstone
I- 4-- Limestone, shell
S. .Freshwater

19 0 ,.. limestone
1 0J Limestone, sandy,
shelly

L < Sand and shell
21 Unconformity

Figure 7. Detailed stratigraphy of the Caloosahatchee Formation at the Nelson Road Pit in Lee
County.

and shell. It is topped by a hard, indurated limestone containing preserved aragonitic shell. The
sequence is capped with a freshwater limestone with some preserved laminations at the surface.
The Nelson Road Pit is the only known location in the region that contains all three sequences
described by DuBar (compare Figure 7 to 4).
No Caloosahatchee Formation sediments were found in the Chiquita Sand Pit located east
of the Nelson Road Pit. Specifically defined Caloosahatchee Formation sediments have not
been identified at any other location to the south in Lee or Collier counties.

SPECIAL PUBLICATION NO. 49

Fort Thompson Formation
The Fort Thompson Formation was originally described as a predominantly carbonate unit
based on outcrops located along the Caloosahatchee River and the carbonate shell deposits
found in a number of pits in South Florida (Dall, 1890-1903; DuBar, 1958). After DuBar (1962)
studied the stratigraphy of the Fort Thompson Formation in the Charlotte Harbor area and north-
western Lee County, the definition of the Fort Thompson Formation was forced to include pre-
dominantly siliciclastic and mixed carbonate and siliciclastic sediments. DuBar (1962) recog-
nized two separate quartz sand units within the formation in the Charlotte Harbor area, but did
not formally separate them.
Based on the stratigraphic sections described in the pits along Charlotte Harbor, there are
two or three different stratigraphic units within the Fort Thompson Formation in this region.
These units may represent individual sequences related to two separate sea level events or may
be a single sequence containing a discontinuity. The uppermost unit, above a laminated crust
representing an unconformity is problematical and may represent a very late sea-level deposit
or may be an erosional deposit related to soil development.
At the Burnt Store Road North Pit, the Fort Thompson Formation is clearly divided into three
different stratigraphic units (Figure 5). At the base of the formation, there is a shell bed averag-
ing about 12 inches in thickness. This unit is predominantly aragonitic shell with a minor amount
of quartz sand. The overlying unit consists of a shell and sand bed about 5 feet thick capped
by a laminated sandstone. The uppermost unit is a quartz sand containing little on no carbon-
ate and is sometimes laminated.
The Fort Thompson Formation section at the Nelson Road Pit is quite similar to the Burnt
Store Road North Pit (Figure 6). The section consists of three stratigraphic units. The lowest
unit is a shell and sand bed containing aragonitic shell, quartz sand, and some mud. The mid-
dle unit is a sand and shell bed capped by a laminated sandstone. Quartz sand is the predom-
inant component of the middle unit with up to 70% by volume. About 60 cm of quartz sand over-
lies the laminated crust. The uppermost quartz sand unit contains little or no carbonate.
There is again a clear similarity between the Fort Thompson Formation stratigraphy at the
Chiquita Sand Pit and the pits described (Figure 8). There are three stratigraphic units with the
lowest unit being a shell and quartz sand with a minor quantity of mud. The middle unit is pre-
dominantly quartz sand with 10 to 20% shell and no mud and is capped by a laminated sand-
stone crust. About 2.5 feet of sand occurs as the uppermost unit, which contains a typical soil
profile.

Age of the Neogene Stratigraphic Units
The most recent data available on the age of the Neogene formations discussed in this
paper was collected from Florida Geological Survey core W-16242, located at South Seas
Plantation on Captiva Island east of pit sites (Missimer, 1997). Based on this work, the estimat-
ed age ranges using the time scale of Berggren et al. (1995) for the formations discussed are:
Tamiami Formation, 4.29 to 2.15 Ma; Caloosahatchee Formation, 2.14 or 1.77 to 0.6 Ma; and
Fort Thompson Formation, 0.6 to 0.12 Ma. The Pinecrest Member of the Tamiami Formation has
an age range of 3.22 to 2.15 Ma in this core. These estimated age ranges for the formations are
likely to be similar for the sections discussed based on the close proximity of the Captive Island
core to the pit locations.

DISCUSSION

Study of the Neogene geology of the Charlotte Harbor area indicates that there is consid-
erable spatial variability in the lithologic units constituting the Tamiami, Caloosahatchee and Fort

FLORIDA GEOLOGICAL SURVEY

Thompson formations. Conventional lithostratigraphic correlation is not possible, but mapping
of regional disconformities does allow correlation of time-equivalent units because of the
relatively flat relief of the South Florida Platform (Perkins 1977).
At nearly every location studied, the Tamiami Formation is predominantly a siliciclastic unit
consisting of quartz sand with calcitic shell or slightly cemented quartz sand. The described
lithologic unit is equivalent to the Sand Facies of Missimer (1992). The only location containing
any section of the Pinecrest Member is the Acline Pit, which is further evidence that the Pinecrest
Member is not a regionally mappable stratigraphic unit.
There are two disconformities within the Caloosahatchee Formation that divide it into three
sequences or parasequences. It is likely that each of the three units found represent a single
sea-level event based on the generally shoaling-upward nature of the sediments (note the depth

I-

LU

a

5

10

15

20

i

I-

- Sand, white, brown

-. Sandstone,
laminated

Sand, with shell
(15-20%), white

Shell, with sand
(30-40%), gray,
slightly muddy

Sandstone,
barnacles,
Ostrea

Figure 8. Neogene stratigraphy of the Chiquita Sand Pit in Lee County.

SPECIAL PUBLICATION NO. 49

of water in which the sediments were deposited becomes progressively shallower). Based on
recent age-dating work by Missimer (1997), the uppermost sequence is likely a Pleistocene sea-
level event while the lower two sequences are Pliocene events. Similar
ages for these sediments was determined by Jones et al. (1991) in Sarasota County.
Three different lithologic units were found within the Fort Thompson Formation. These units
show remarkable uniformity in composition. The units become progressively more siliciclastic
from bottom to top of the formation.

CONCLUSIONS

Over the last 4 million years, the geological character of the Charlotte Harbor region has
changed considerably. When the Tamiami Formation was being deposited, the area was pre-
dominantly a sandy, shallow marine environment, similar to the current conditions on the West
Florida shelf with deeper water (Meeder 1987). Based on the work of Meeder (1987), the cli-
mate of the region was subtropical, but perhaps cooler than present. During the later period of
Tamiami Formation deposition, massive shell beds of the Pinecrest Member were deposited in
isolated areas, such as Acline. Deposition of these shell beds is believed to be the result of
storms and processes occurring in shallow coastal waters (Allmon 1993).
During deposition of the Caloosahatchee Formation, there were three sea level events that
showed a rise and then a succeeding recession. Based on the occurrence of tropical and sub-
tropical mollusks and corals in the sediments, and oxygen isotope data collected on core W-
16242 located on Captiva Island (Missimer 1997), the region was perhaps warmer than during
deposition of the Tamiami Formation and showed a greater diversity of depositional environ-
ments ranging from shallow shelf or ramp to open bay, to lagoonal or embayment. The deposi-
tional environments are similar to those currently existing from Cape Sable south to Florida Bay
and to the west on the shelf. Not as much quartz sand was entering the marine environment
during this time, which may indicate that sea level was slightly higher than today.
Sediments of the Fort Thompson Formation show characteristics similar to those currently
being deposited as barrier islands, such as Sanibel Island. The general climatic conditions were
similar to today based on the mollusk assemblage. Large quantities of quartz sand were being
deposited with the mollusks. The environment probably looked similar to today with the shell and
sand deposits occurring along the coast and on the shallow shelf with the muddier sediments
being deposited in shallow embayments, such as the upper part of Charlotte Harbor and the inte-
rior of the Caloosahatchee River embayment.

RESEARCH NEEDS

Although numerous geologic, paleontologic, and seismic reflection studies have been made
of the region in and around Charlotte Harbor, no significant synthesis of the work has been
accomplished. It would be extremely useful to correlate the seismic reflection data collected by
Evans et al. (1989) and Evans and Hine (1991) with the lithostratigraphy in this paper and the
paleontological studies of the past to produce a depositional model of the region through time.

ACKNOWLEDGMENTS

I thank the many geologists that accompanied me during field mapping and sample collec-
tion. This group includes: F. Sternes McNeill (deceased), Durward H. Boggess (deceased),
Thomas M. Scott, Roger Portall, Victor Zullo (deceased), Bill Harris, and many others. Charles
Walker reviewed this manuscript and added helpful comments.

FLORIDA GEOLOGICAL SURVEY

REFERENCES

Berggren, W. A., D. V. Kent, C. C. Swisher, III, and M. P. Aubry. 1995. A revised Cenozoic
geochronology and chronostratigraphy. Pp. 129-212 in: Berggren, W. A., D. V. Kent, M. P.
Aubry, and J. Hardenbol, editors, Geochronology, time scales and global stratigraphic cor-
relation, Soc. Econ. Paleont. Mineral. Spec. Pub. No. 54.

Dall, W. H. 1890-1903. Contributions to the Tertiary fauna of Florida with special reference to the
Miocene Silex beds of Tampa and the Pliocene beds of the Caloosahatchee River. Wagner
Free Institute Science Trans., v. 3, 6 parts, 1654 pp.

DuBar, J. R. 1958. Stratigraphy and paleontology of the late Neogene strata of the
Caloosahatchee River area of southern Florida. Florida Geological Survey Bull. 40, 267pp.

DuBar, J. R. 1962. Neogene biostratigraphy of the Charlotte Harbor area in Southwestern
Florida. Florida Geological Survey Geological Bulletin No. 43, 83pp.

Evans, M.W. and A.C. Hine. 1991. Late Neogene sequence stratigraphy of a carbonate-silici-
clastic transition: Southwest Florida: Geol. Soc. Am. Bull., 103: 679-699.

Heilprin, A. 1887. Explorations on the West Coast of Florida and in the Okeechobee Wilderness.
Wagner Free Institute of Philadelphia, 134p.

Jones, D.S., B.J. MacFadden, S.D. Webb, P.A. Mueller, D.A. Hoddell, and T.M. Cronin. 1991.
Intergrated geochronology of a classic Pliocene fossil site in Florida: Linking marine and ter-
restrial biochronologies: Jour. of Geology, v. 99, p. 637-648.

Meeder, J.F. 1987. The paleoecology, petrology and depositional model of the Pliocene Tamiami
Formation, Southwest Florida (with special reference to corals and reef development): Ph.D.
dissertation, Univ. of Miami, Coral Gables, Florida, 749 pp.

Missimer, T. M. 1992. Stratigraphic relationships of sediment facies within the Tamiami
Formation of Southwest Florida: Proposed intraformational correlations. Pp. 63-92 in Scott,
T. M., and W. A. Allmon, eds., The Plio-Pleistocene Stratigraphy and Paleontology of
Southern Florida. Florida Geological Survey Special Publication No. 36.

Missimer, T. M. 1993. Pliocene stratigraphy of southern Florida: Unresolved issues of facies cor-
relation in time. Pp. 33-42 in Zullo, V. A., W. B. Harris, T. M. Scott, and R. W Portell, The
Neogene of Florida and Adjacent Regions, Proceedings of the Third Bald Head Island
Conference on Coastal Plains Geology. Florida Geological Survey Special Publication 37.

Missimer, T. M. 1997. Late Oligocene to Pliocene evolution of the central portion of the South
Florida Platform: Mixing of siliciclastic and carbonate sediments. Unpublished Ph.D. dis-
sertation, University of Miami, Coral Gables, Florida, 2 volumes, 1001 pp.

Olsson, A. A., and A. Harbison. 1953. Pliocene Mollusca of Southern Florida. Acad. of Natural
Science, Philadelphia, Mon. 8, 457pp.

SPECIAL PUBLICATION NO. 49

Perkins, R. D. 1977. Depositional framework of Pleistocene rocks in South Florida. Pp.131-198
in Enos, P., and R. D. Perkins, Quaternary sedimentation in South Florida. Geological
Society of America Memoir 147.

Tucker, H. I., and D. Wilson. 1932a. Some new and otherwise interesting fossils from the Florida
Tertiary. Bull. Am. Paleontology 18:39-82.

Tucker, H.I. and D. Wilson. 1932b. A list of species from Acline, Florida: Indiana Acad. Sci. Proc.,
v. 41, p. 357.

Van Wagoner, J.C., R.M. Mitchum, K.M. Campion and V.D. Rahmanian. 1990. Siliciclastic
sequence stratigraphy in well logs, cores and outcrops: Concepts for high-resolution corre-
lation of time and faces: AAPG Methods in Exploration Series No. 7, Am. Assoc. of
Petroleum Geologists, Tulsa, Okla., 55 pp.

SPECIAL PUBLICATION NO. 49

SEQUENCE STRATIGRAPHY OF A SOUTH FLORIDA CARBONATE RAMP AND
BOUNDING SILICICLASTICS (LATE MIOCENE-PLIOCENE)

Kevin J. Cunningham1, David Bukry2, Tokiyuki Sato3, John A. Barron2,
Laura A. Guertin4, and Ronald S. Reese1
1. U.S. Geological Survey, 9100 N.W. 36th Street, Suite 107, Miami, FL 33178
2. U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025
3. Institute of Applied Earth Sciences, Mining College, Akita University, Tegata-Gakuencho 1-1, Akita, 010, Japan
4. Mary Washington College, Fredericksburg, VA 22401

ABSTRACT

In southern peninsular Florida, a late-early to early-late Pliocene carbonate ramp (Ochopee
Limestone Member of the Tamiami Formation) is sandwiched between underlying marine silici-
clastics of the late Miocene to early Pliocene Peace River Formation and an overlying late
Pliocene unnamed sand. At least three depositional sequences (DS1, DS2, and DS3), of which
two contain condensed sections, are recognized in the Peace River Formation; an additional
depositional sequence (DS4) is proposed to include the Ochopee Limestone.
Established chronologies and new biostratigraphic results indicate that the Tortonian and
Zanclean ages bracket the Peace River Formation. Depositional sequence 1 (DS1) prograded
across the present-day peninsular portion of the Florida Platform during the Tortonian age and
laps out near the southern margin of the peninsula. During the latest Tortonian and Messinian
ages, progradation of DS2 overstepped the southern lap out of DS1 and extended at least as far
as the Florida Keys. Deposition of DS2 ended, at the latest, near the Miocene-Pliocene bound-
ary. Siliciclastic supply was reduced during early Pliocene deposition of DS3, which is absent in
southernmost peninsular Florida. This reduction in supply of siliciclastics was followed by aggra-
dational accumulation of heterozoan temperate carbonate sediments on a widespread carbon-
ate ramp that includes the Ochopee Limestone. The Ochopee Limestone was deposited during
eustatic cycle TB3.6 and ended in the late Pliocene with basinward lap out near the southern
margin of the Florida peninsula. The Ochopee Limestone ramp was buried with a late Pliocene
resumption of southward influx of siliciclastics (unnamed sand and Long Key Formation) that
extended south beyond the middle and upper Florida Keys.

INTRODUCTION

Until the early 1990's, stratigraphic investigations of Miocene-Pliocene siliciclastics and car-
bonates beneath southern Florida focused on lithostratigraphy (Peck et al., 1979; Wedderburn
et al., 1982; Peacock, 1983; Missimer, 1984; Knapp et al., 1986; Scott, 1988; Smith and Adams,
1988; Missimer, 1992). Recently, sequence stratigraphy has contributed to conceptualizing a
more accurate spatial and temporal framework of the Miocene-Pliocene stratigraphic framework
of southern Florida (Evans and Hine, 1991; Warzeski et al., 1996; Missimer, 1997; Cunningham
et al., 1998; Guertin et al., 1999; Missimer, 1999; Guertin et al., 2000). This developing
sequence-stratigraphic framework for southern Florida is the result of integrating lithostratigra-
phy, micropaleontology, magnetostratigraphy, strontium-isotope chemostratigraphy, and seismic
stratigraphy along with delineating unconformities that bound depositional sequences (Missimer,
1997; Weedman et al., 1997; Cunningham et al., 1998; Edwards et al., 1998; Guertin, 1998;
Missimer, 1999; Weedman et al., 1999). The purpose of this study is to integrate new lithologic
and paleontologic data with established subsurface data to more accu-rately describe the region-
al lithostratigraphic and sequence-stratigraphic framework of the Miocene-Pliocene siliciclastics

FLORIDA GEOLOGICAL SURVEY

and carbonates of southern Florida. Correlating these data will improve understanding of the
regional stratigraphic framework and constrain time boundaries for depositional sequences.

METHODS

A total of 89 coreholes and cuttings from 18 test wells were used to map lithostratigraphic
boundaries and to develop facies associations and sequence stratigraphy (Fig. 1). The cuttings
were described using a binocular microscope. Descriptions of the cores are from Causaras
(1985), Causaras (1987), Fish (1988), Fish and Stewart (1991), McNeill et al. (1996), Missimer
(1997), Weedman et al. (1997), Cunningham et al., (1998), Edwards et al., (1998), Guertin
(1998), Weedman et al. (1999), Reese and Cunningham (2000, in press), and from the data
archives of the Florida Geological Survey and U.S. Geological Survey.
Co-authors David Bukry and Tokiyuki Sato identified coccolith taxonomy, and John Barron
determined diatom taxonomy. Bukry and Barron conducted identifications by standard U.S.
Geological Survey methods. Sato identified coccoliths for each sample by counting 200 nanno-
fossil specimens for quantitative analysis. The terms abundant (greater than 32 percent of spec-
imens in total assemblage), common (32 to 8 percent of specimens in total assemblage), rare
(less than 8 percent of specimens in total assem-blage) and present (found but not counted)
were used to describe quantitatively coccolith populations defined by Sato. Coccolith taxomony
has been assigned to the biostratigraphic zones of Okada and Bukry (1980) as calibrated to the
coccolith datums of ODP Leg 171B from the Blake Nose east of northern Florida (Shipboard
Scientific Party, 1998) with normalized modifications from Bukry (1991).
Co-author Laura Guertin identified benthic foraminifera at the genus level using data from
Bock et al. (1971), Poag (1981), and Jones (1994). Paleoenvironmental interpretations are
based on grouping of individual benthic foraminiferal associations and species into the broad
depth categories of inner and outer shelf, defined as mean sea level to an approximate water
depth of about 305 feet and from about 305 to 610 feet, respectively (Murray, 1991). Ages are
reported in accordance with the integrated magnetobiochronologic Cenozoic time scale of
Berggren et al. (1995).

CARBONATE RAMP AND BOUNDING SILICICLASTICS
TEMPORAL AND SPATIAL BOUNDARIES

Lithologic units of primary interest in this study, from oldest to youngest, are the Peace River
Formation of the Hawthorn Group, Ochopee Limestone Member of the Tamiami Formation, and
an unnamed sand member (Fig. 2). Facies associations pre-sented for the Peace River
Formation, Ochopee Limestone, and unnamed sand are based on examination of cores and on
existing descriptions within the study areas outlined in Figure 1.

Peace River Formation
Lithostratigraphy
Three depositional sequences (DS1, DS2, and DS3) are newly defined on a regional scale
within the Peace River Formation (Fig. 2). Although interpreted to be depositional sequences,
DS3 actually may be a parasequence. Much of the lithofacies analysis completed by Reese and
Cunningham (2000, in press) for southeastern Florida was limited mostly to DS2 and DS3.
Depositional sequence 1 (DS1) was characterized primarily by Weedman et al. (1997) and
Edwards et al. (1998). Five lithofacies have been identified by Reese and Cunningham (2000, in
press) for the upper part of the Peace River Formation in an area shown in Figure 1: (1) diatoma-

SPECIAL PUBLICATION NO. 49

0 REVERSE-AIR CORE
* DRILL CUTTINGS
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	Front Cover
	Frontispiece
	Title Page
	Letter of transmittal
	Table of Contents
	Dedication
	Acknowledgement
	List of participants and contr...
	Contributions of Durward H. Boggess...
	The surficial geology of Lee county...
	Late neogene geology of northwestern...
	Sequence stratigraphy of a south...
	Late paleogene and neogene chronostratigraphy...
	The hydrogeology of Lee County,...
	Water level elevation maps of the...
	Hydrogeologic implications of Uranium-rich...
	Hydrogeology of the lower Floridian...
	Caloosahatchee basin integrated...
	Surface water management in Lee...
	Seagrass meadow hourly dissolved-oxygen...
	The Lee County abandoned well...
	Back Cover

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