|UFDC Home||myUFDC Home | Help ||
|Maps and charts|
CITATION SEARCH THUMBNAILS PAGE IMAGE ZOOMABLE
STANDARD VIEW MARC VIEW
|Table of Contents|
Title Page 1
Title Page 2
Page 2 (MULTIPLE)
Page 6 (MULTIPLE)
Maps and charts
FLRD GEOLOSk ( IC SUfRiW
[year of publication as printed] Florida Geological Survey [source text]
The Florida Geological Survey holds all rights to the source text of
this electronic resource on behalf of the State of Florida. The
Florida Geological Survey shall be considered the copyright holder
for the text of this publication.
Under the Statutes of the State of Florida (FS 257.05; 257.105, and
377.075), the Florida Geologic Survey (Tallahassee, FL), publisher of
the Florida Geologic Survey, as a division of state government,
makes its documents public (i.e., published) and extends to the
state's official agencies and libraries, including the University of
Florida's Smathers Libraries, rights of reproduction.
The Florida Geological Survey has made its publications available to
the University of Florida, on behalf of the State University System of
Florida, for the purpose of digitization and Internet distribution.
The Florida Geological Survey reserves all rights to its publications.
All uses, excluding those made under "fair use" provisions of U.S.
copyright legislation (U.S. Code, Title 17, Section 107), are
restricted. Contact the Florida Geological Survey for additional
information and permissions.
State of Florida
Department of Natural Resources
Elton J. Gissendanner, Executive Director
Division of Resource Management
Charles W. Hendry, Jr., Director
Florida Geological Survey
Steve R. Windham, Chief
Open File Report 11
Geology of DeSoto County, Florida
Kenneth M. Campbell
Florida Geological Survey
3 1262 04543 6317
Geology of DeSoto County, Floridat Ge
Florida Bureau ot Geology ta
BY 903 %.Tennsee st
Tahas FL 32304
Kenneth M. Campbell
Florida Geological Survey
Several authors have discussed the physiography of the Florida peninsula.
For the purposes of this report, White's (1970) classification will be utilized.
The vast majority of DeSoto County lies within the DeSoto Plain (Fig. 1). Por-
tions of the southwest corner of the county fall within the boundaries of the
Gulf Coastal Lowlands.
Elevations within the county range from very near sea level in the southwest
corner along the lower Peace River valley, to 90-95 feet in the northeast corner
of the county. Elevations increase almost imperceptably from the southwest
toward the northeast. The topography tends to be flat with relatively steeper
slopes in the vicinity of streams. Much of the interstream area is poorly
drained. Many swamps, marshes and ponds are present throughout the county. The
Peace River, Horse Creek and Joshua Creek are the major streams within the county.
The DeSoto Plain is a very flat area located primarily in Manatee, Hardee,
DeSoto, Highlands, Glades and Charlotte counties. White (1970) believes that
the DeSoto Plain is a submarine plain probably formed under Pleistocene Wicomico
seas (70 100 feet above present sea level). White (1970) cites the notable
absence of relict shoreline features as evidence of the submarine origin of the
Gulf Coastal Lowlands
The southwest corner of DeSoto County is located within the Gulf Coastal
Lowlands (White, 1970). The prominent topographic features of the Gulf Coastal
Lowlands within DeSoto County include scarps and terraces developed during
Pleistocene sea level stands and the entrenched Peace River Valley. Healy
(1975a) shows two terraces within the Gulf Coastal Lowlands portion of DeSoto
County. The Pamlico terrace is found at elevations of approximately 8-25 feet
above mean sea level; the Talbot at 25-42 feet. Both of these terraces extend
up the entrenched Peace River Valley. Except within the Peace River Valley,
these "terraces" are poorly defined elevation zones. The flood plain of the
Peace River lies as much as 30 feet below the surrounding upland surface in this
Surface and near surface sediments in DeSoto County consist of quartz sand,
clay, limestone and dolomite. These sediments range in age from Oligocene
(38-22.5 million years ago) to Holocene (10,000 years ago to present).
The Suwannee Limestone is present throughout DeSoto County in the subsurface.
The Suwannee Limestone is a creamy white to light yellowish grey limestone,
variably textured (wackestone to packstone), poorly to well indurated and variably
recrystalllzed. The upper portions are highly fossiliferous (predominantly
poorly preserved foraminifera, with molluscs, echinoids and corals). Moldic
and vuggy porosity is common.
The top of the Suwannee Limestone is encountered at approximately 350 feet
below mean sea level in the northeastern and northwestern corners of the county,
and dips generally to the south and south-southeast. In the southeastern corner
of the county, the top of the Suwannee Limestone is encountered at depths of
approximately 700 feet below mean sea level (Scott, in press; Wilson, 1977).
The thickness of the Suwannee ranges from approximately 140 feet to over
400 feet within the county (Wilson, 1977). The thinnest portion is in extreme
northeastern DeSoto County, while the thickest portion is along the central por-
tion of the western edge of the county.
Scott (in press) has raised the Hawthorn from formation status to group status.
The Hawthorn Group will include those sediments which in the past have been
included in the Tampa, Hawthorn and Bone Valley formations. In DeSoto County,
the Hawthorn Group consists of, in ascending order, the Arcadia Formation and
the Peace River Formation.
The Arcadia Formation (Scott, in press) is named after the town of Arcadia
in DeSoto County. The type section designated by Scott (in press) is located in
the core W#12050 (see Figure 4) between -96 feet M.S.L. and -216 feet M.S.L.
The Arcadia Formation contains, in ascending order, the Nocatee and Tampa members
and an unnamed member.
The Nocatee Member of the Arcadia Formation is named for the town of
Nocatee in central DeSoto County and is present throughout DeSoto County. The
sediments included in the Nocatee have previously been called the "sand and clay
unit" of the Tampa Limestone (Wilson, 1977).
Lithologically, the Nocatee consists of a complexly interbedded sequence of
variably phosphatic quartz sands, clays and carbonates (Scott, in press). The
Nocatee is predominantly a plastic (sand and clay) unit. Quartz sands are typi-
cally fine to coarse grained, sometimes silty, clayey, calcareous or dolomitic
and variably phosphatic (Scott, in press). Clay beds are common. The clays are
variably quartz sandy and silty, phosphatic and calcareous to dolomitic.
Carbonate beds are subordinate within the Nocatee (Scott, in press).
The top of the Nocatee Member of the Arcadia Formation within DeSoto County
is encountered at elevations which range from approximately -200 feet M.S.L. to
approximately -450 feet M.S.L. (Scott, in-press). .The.upper surface dips to the
south and south-southeast. The thickness of the Nocatee within the county
ranges from approximately 125 to slightly more than 200 feet.
The Tampa Member of the Arcadia Formation is lithologically similar to the
type Tampa Formation of King and Wright (1979), but has a slightly greater phos-
phate content (1-3 percent) and greater area extent (Scott, in press). The
Tampa Member is a white to tan-colored, quartz sandy limestone with a carbonate
mud matrix. Varying amounts of clay are usually disseminated throughout the
rock (King and Wright, 1979; Scott, in press). Some beds within the Tampa
Member contain more than 50 percent quartz sand. Dolomite is relatively uncom-
mon within the Tampa Member (King and Wright, 1979; Scott, in press).
The Tampa Member is recognizable throughout most of DeSoto County, however
the unit becomes indistinct due to a faces change in eastern DeSoto County and
south of the DeSoto/Charlotte county line (Scott, in press).
The top of the Tampa Member is encountered between 150 and 200 feet
below mean sea level in DeSoto County (Scott, in press). Thickness of the Tampa
ranges from 50 to 100 feet (Scott, in press).
The upper (unnamed) member of the Arcadia Formation includes those sedi-
ments which in the past have been referred to as the "Hawthorn carbonate unit"
(Scott, in press). Lithologically, these sediments consist of white to yellow-
ish grey, quartz sandy, phosphatic and sometimes clayey, dolomites and lime-
stones (uncommon). Occasional beds of carbonate rich quartz sand and thin clay
beds are present.
The upper member of the Arcadia is present throughout DeSoto County. In
those areas where the Tampa and Nocatee Members are not recognized, the entire
formation remains undifferentiated. The top of the Arcadia Formation ranges
from near mean sea level in the northern part of the county to slightly more
than 100 feet below mean sea level and dips generally in a south-southeast
direction. Where the Arcadia is differentiated, the upper member is approxima-
tely 100 to 140 feet thick. The thickness of the entire Arcadia Formation,
within the county, ranges from slightly less than 300 feet to more than 500 feet
(Scott, in press).
Peace River Formation
The Peace River Formation (Scott, in press) in DeSoto County consists of
those sediments which have been described in the past, as "upper Hawthorn
clastics." The type section designated by Scott (in press) is well #12050
(section 16, township 38S, range 26E, DeSoto County) between +41 and -97 feet
MSL. Lithologically, these sediments consist of yellowish-grey to light olive
green interbedded phosphatic sands, clayey sands, clays and dolomite stringers.
The top of the Peace River Formation is found at or near mean sea level
throughout much of the county (Scott, in press). In northwestern DeSoto County,
however, the Peace River Formation is encountered at 50 feet above mean sea
level. The base of the Peace River is gradational with the underlying Arcadia
Formation, and is picked at the point where the sediments change from predomi-
nantly plastic to predominantly carbonate (Scott, in press).
The thickness of the Peace River Formation is approximately 50 feet in the
northeastern and southwestern corners of the county. The Peace River thickens
to more than 160 feet in the southeastern corner of the county. The Peace River
dips, and thickens in a general south easterly direction.
Undifferentiated Surficial Sands and Shell
Surficial deposits of Pliocene-Pleistocene age (5.3 to .01 million years
ago) blanket the county. Throughout the majority of the county, the surficial
deposits consist of silty, clayey, shelly sands and variably indurated shell
beds. The shell beds are generally limited to the southern third of the county.
The undifferentiated surficial sands and shell range from 10-30 feet thick
throughout the majority of the county. Surficial sediments thicken in the south
central portion of the county and along the DeSoto/Highlands county line.
Clean quartz sand of Pleistocene age (1.6 to..01 million years ago) forms a
veneer over the clayey shelly sands. These deposits consist of unconsolidated
very fine to medium grained quartz sand. The sands are white to light brown in
color and contain trace amounts of phosphate sand and limestone or shell
Deposits of Holocene age (10,000 years ago to present) are primarily
limited to present day stream flood plains, beaches, swamps, marshes and lakes.
these sediments consist of sand, silt, clay and organic materials.
Groundwater in DeSoto County is obtained from the surficial aquifer system,
the intermediate aquifer system and from the Floridan Aquifer. The aquifers are
separated by confining layers which restrict vertical water movement between the
Surficial Aquifer System
The surficial aquifer consists primarily of quartz sand and includes the
undifferentiated surficial sands and shell as well as the uppermost portions of
the Peace River Formation. With the exception of some lithified shell beds,
these sediments are unconsolidated.
The top of the surficial aquifer is the ground water table and water within
the surflcial aquifer is generally under unconfined conditions. The base of the
surficial aquifer system is formed by the clayey, less permeable beds of the
Peace R'iver Fotmation'"The surficial aquifer system underlies essentially all
of DeSoto County and is utilized primarily for domestic, lawn irrigation and
stock watering supplies, where high flow notes are not required (Wilson, 1977).
Intermediate Aquifer System
The intermediate aquifer system contains water under confined conditions
and consists primarily of the .limestones and dolomites of the Arcadia Formation.
The intermediate aquifer corresponds with the "upper unit of the Floridan
Aquifer" of Wilson (1977). The upper confining layer of the intermediate
aquifer system consists of the clayey sediments of the Peace River Formation.
The lower confining layer consists of the Nocatee Member of the Arcadia
Within DeSoto County, the intermediate aquifer averages approximately 200
feet in thickness (Wilson, 1977). Typical wells yield up to several hundred
gallons per minute, however, yield is highly variable (Wilson, 1977). The prin-
cipal uses for wells developed in the intermediate aquifer are for domestic and
The Floridan Aquifer consists of the limestones and dolomites of the
Suwannee Limestone and the underlying Ocala Group and Avon Park Limestone. The
Floridan contains water under confined conditions. In DeSoto County, the upper
confining layer consists of the Nocatee Member of the Arcadia Formation. The
top of the Floridan is encountered at approximately 300 feet below mean sea
level in the northwestern corner of the county and dips to approximately 750
feet below mean sea level in the southeastern corner (Buono and Rutledge, 1978).
Wells developed in the Floridan Aquifer yield large quantities of water,
often in excess of 1000 gallons per minute (Wilson, 1977). The primary use of
water from the Floridan Is large scale inigation. Water quality of the Floridan
Aquifer is generally poorer than in the surficial and intermediate aquifers.
Water quality In both the Floridan and the intermediate aquifer decreases in a
general southwesterly direction (Wilson, 1977).
Areas of Artesian Flow
Both the intermediate and the Floridan aquifers are under confined con-
ditions and may contribute to artesian flow. Healy (1975b) shows the south-
western portion of the county as an area of artesian flow. This area emcom-
passes the entire Peace River Valley, portions of the Horse Creek and Joshua
Creek drainages and the Gulf Coastal Lowlands as well as the southwestern edge
of the DeSoto Plain. Barr and Schiner (1983) show potentiometric surface eleva-
tions of 40-50 feet above mean sea level for much of the same area.
Barr, G. L., and Schiner, G. R., 1983, Potentiometric surface of the Floridan
Aquifer, Southwest Florida Water Management District, May, 1983, U. S.
Geol. Survey, O.F.R. 83-547.
Buono, A., and Rutledge, A. T., 1978, Configuration of the top of the Floridan
Aquifer, Southwest Florida Water Management District, and adjacent areas,
U. S. Geol. Survey, Water Resources Investigation 78-34.
Healy, H. G., 1975a, Terraces and shorelines of Florida, Florida Bureau of
Geology, Map Series #71.
1975b, Piezometric map with the area of artesian flow of the
Floridan Aquifer in Florida, Revised 1975, Florida Bureau of Geology, Map
Series #4 Revised.
King, K. C. and Wright, R., 1979, Revision of the Tampa Formation, west-central
Florida, Transactions, Gulf Coast Association of Geological Societies, vol.
XXIX, pp. 257-261.
Scott, T. M., 1985, The regional lithostratigraphy of the Hawthorn Group Miocene
of Florida, Florida Bureau of Geology, Bull. #59, manuscript in press.
White, W. A., 1970, Geomorphology of the Florida peninsula, Florida Bureau of
Geology, Bull. #51, 164p.
Wilson, W. E., 1977, Ground water resources of DeSoto and Hardee Counties,
Florida, Florida Bureau of Geology, Report of Invest. #83, 102p.
Rad 1/- Vj/
444 0 0 /x
. Jo -
.4 ocvrzoV A/RP
............................... .......... iiiiiiiiiii .. --Irr~--l CICCI-
SARASOTA CO.IDESOTO CO. W-12311
W-12948 W- 12050 T37S R27ES26ec
W- 2983 W- 15303 T37S.R24E.S34CEN T38S.R26E.51644
T38S.R2 2E.S2 1 T 388R23E.S 14hb
MSL -- SUPEACE RtVE R FORMATION
ARCADIA FORMATION ARCADIA FORMATION
-soo- SUWANNEE LMESTONE- S00
HARDEE CO. DESOTO CO.
1 SURFICIAL SANDS
PECaE RIVER FORMATION
DESOTO CO.I CHARLOTTE CO.
SURFICIAL SANDS & SHELL
ARCADIA PEACE RIVER FORMATIONFORMATION
SUWAN---Ee BASE OF jil
m ---- --
PEACE RIVER FORMATIO