Citation
The geomorphology and geology of Liberty County, Florida ( FGS: Open file report 43 )

Material Information

Title:
The geomorphology and geology of Liberty County, Florida ( FGS: Open file report 43 )
Series Title:
( FGS: Open file report 43 )
Creator:
Rupert, Frank
Florida Geological Survey
Place of Publication:
Tallahassee
Publisher:
Florida Geological Survey
Publication Date:
Language:
English
Physical Description:
9 p. : ill., map ; 28 cm.

Subjects

Subjects / Keywords:
Geomorphology -- Florida -- Liberty County ( lcsh )
Geology -- Florida -- Liberty County ( lcsh )
Liberty County (Fla.) ( lcsh )
Liberty County ( local )
City of Apalachicola ( local )
City of Tallahassee ( local )
Town of Suwannee ( local )
City of Chattahoochee ( local )
City of St. Marks ( local )
Limestones ( jstor )
Aquifers ( jstor )
Sediments ( jstor )
Geological surveys ( jstor )
Sand ( jstor )
Genre:
bibliography ( marcgt )
non-fiction ( marcgt )

Notes

Bibliography:
Includes bibliographical references (p. 8-9).
General Note:
Title from cover.
General Note:
At head of title: State of Florida, Department of Natural Resources, Division of Resource Management, Florida Geological Survey.
Funding:
Digitized as a collaborative project with the Florida Geological Survey, Florida Department of Environmental Protection.
Statement of Responsibility:
by Frank R. Rupert.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier:
027837622 ( aleph )
25641792 ( oclc )
AJG7173 ( notis )

Downloads

This item has the following downloads:


Full Text







STATE OF FLORIDA DEPARTMENT OF NATURAL RESOURCES
Tom Gardner, Executive Director







DIVISION OF RESOURCE MANAGEMENT Jeremy A. Craft, Director






FLORIDA GEOLOGICAL SURVEY
Walter Schmidt, State Geologist and Chief












OPEN FILE REPORT NO. 43 THE GEOMORPHOLOGY AND GEOLOGY OF LIBERTY COUNTY, FLORIDA BY

Frank R. Rupert






2ji' S 1DA LIBRARIES








FLORIDA GEOLOGICAL SURVEY Tallahassee
1991

























LI DARY










The geomorphology and geology of Liberty County, Florida

Frank R. Rupert, P.G. No. 149


GEOMORPHOLOGY characterized by a generally flat and often swampy,
seaward-sloping, sandy plain. Most of the lowlands Liberty County is situated in the Northern Zone area is ancient marine terrace, shaped by highgeomorphic province of White (1970), which standing Pleistocene seas. Today, much of southern
includes the northern Florida peninsula and all of Liberty County is covered by shallow, denslythe panhandle. In this portion of the east-central wooded swamp-like areas called "bays", and poorlyFlorida panhandle, the Northern Zone is divided defined creeks. Elevations in the Gulf Coastal into four geomorphic subzones based primarily on Lowlands of Liberty County range from between 20 topographic elevations. These include the Gulf and 25 feet above mean sea level (MSL) at the Coastal Lowlands, Beacon Slope, the Tallahassee southern end of the county to approximately 100 Hills, and the River Valley Lowlands (Figure 1). feet above MSL where the lowlands meet the higher
The Gulf Coastal Lowlands comprise much of slopes in northern Liberty County.
southern Liberty County. This subzone is An elevationally-transistional gemorphic zone

JACK0N CO.,N
-748
OL 1'

EXPLANATION
-- 6 -6599
-:- STATE/COUNTY ROAD
-3 0 CORE
-* CROSS SECTION LOCATION ESTIFFAN LOA
-- -.-- TALLAHASSEE HILLS

-4BEACON SLOPE GULF COASTAL LOWLANDS APALACHICOLA RIVER VALLEY LOWLANDS
C3OCHLOCKONEE RIVER
:1 VALLEY LOWLANDS
--- CODY SCARP
MILES
0 1 2 3 4 5
KILOMETERS

01UMATRA
FRANKLIN CO.


A' W-14890
Figure 1: Geomorphic and cross section location map of Liberty County.

1.








named the Beacon Slope (White et al., 1964) The river bluffs are commonly dissected by a
separates the Gulf Coastal Lowlands from the series of deep, east-west trending ravines containing
siliciclastic hills of northern Liberty County. The small creeks which drain into the Apalachicola Beacon Slope is a uniformly-sloping, ramp-like River. Many of these ravines extend several miles feature linking the topographically higher east of the river, ending at so-called "steepheads" Tallahassee Hills on the north with the Gulf Coastal (Sellards and Gunter, 1918). Steepheads form from Lowlands, Near-surface sediments are largely lateral undercutting of the sandy surficial sediments siliclastics overlying karstic limestone. Swampy by water seeping out of the surficial aquifer system. depressions and cover-subsidence sinks are common Ground water percolates downward through the throughout this terrain. In Liberty County, surficial sediments until it encounters a clay or marl.
elevations range from about 100 feet MSL at the It then travels horizontally over the less permeable southern edge of the slope to approximately 200 strata and emerges as a small spring or seep at a feet MSL at the northern edge, where it adjoins the bluff face. Gradually, the flowing water undermines Cody Scarp. The origin of the Beacon Slope is the overburden material, which slumps off forming uncertain, but it is most likely an erosional feature a semicircular, steep-walled head. As undermining associated with the higher sea level stands of the and slumping continue through time, the steephead Pleistocene. migrates laterally away from the original bluff face,
A relict southward facing marine escapment cutting a ravine as it progresses. Other steepheads named the Cody Scarp (Puri and Vernon, 1964) may branch off from the original ravine, forming a
forms the boundary between the Beacon Slope and dendritic series of smaller ravines feeding the parent the topographically higher Tallahssee Hills in ravine. northernmost Liberty County. This feature spans The Apalachicola and Ochlockonee Rivers are
much of northern Florida, and is one of the most the major streams flowing in Liberty County. The persistant topographic breaks in the -state. The Apalachicola River forms the western county Cody Scarp has been erosionally obscured in most boundary with adjacent Calhoun County. In of northern Liberty County. In the northeastern northwestern Liberty County, the broad valley of the part of the county, the scarp rises from a toe Apachicola averages 50 feet MSL in elevation. The elevation of approximately 205 feet MSL to a crest river meanders southwestward through a three-mile of about 220 feet MSL, marking the southern extent wide valley, which gradually descends to an of the Tallahassee Hills geomorphic zone. elevation of about 25 feet MSL at the southern edge
The Tallahassee Hills (Cooke, 1939) are a series of Liberty County. Here, the valley coalesces into of topographic highlands spanning the northern the swampy terrain of the Gulf Coastal Lowlands. edge of the eastern Florida panhandle. They are The valley comprises a geomorphic subzone named part of the Northern Highlands geomorphic the Apalachicola River Valley Lowlands.
province, which is thought to be a stream-dissected The Ochlockonee River forms the eastern remnant of a once continous highland plain Liberty County boundary with Leon and Wakulla
spanning southern Georgia and northern Florida. Counties. Originating in Georgia, the river is The Tallahassee Hills are capped by deltaic to dammed as a hydroelectric power source just above shallow marine, clayey sands, silts and clays. Highway 20 in Leon County, forming Lake Talquin. Elevations of the hills within Liberty County vary South of the dam, the Ochlockonee meanders over from approximately 220 feet MSL at the crest of the a broad, swampy valley averaging about one mile Cody Scarp to nearly 250 feet MSL at the northern wide. This valley comprises the Ochlockonee River county boundary. The modern hilly topography is Valley Lowlands geomorphic zone. In northeastern the result of post-depositional dissection and erosion Liberty County, the river valley is approximately 40 by running water. Steep bluffs occur in feet above MSL. Numerous small creeks contribute
northwestern Liberty County, where the Tallahassee to the river along its course, and oxbow lakes are Hills end abruptly at the floodplain of the common along the northern stretch of the river. In
Apalachicola River. The bluffs commonly stand 150 southeastern Liberty County, .the valley broadens feet or more above the floor of the floodplain, considerabily, merging with the low swampy "bays" exposing Miocene to Holocene age strata. Alum of the Apalachicola National Forest. Elevations
Bluff, located about 2.5 miles northwest of Bristol here average about 10 feet above MSL. The on the Apalachicola River, is one of the best Ochlockonee empties into Apalachee Bay, southeast
geologic exposures in Florida (Schmidt, 1983; of Liberty County.
Johnson, 1989). A number of small creeks drain the flat,



2.









swampy terrain of central Liberty County, and depth of 660 feet bis in one municipal water well in
empty into the Apalchicola and Ochlockonee Rivers. the city of Bristol. Because this unit lies in excess Telogia Creek is the largest of these; it enters of 600 feet bls countywide, it is not used extensively northeastern Liberty County from adjacent Gadsden as a water source in Liberty County. The Ocala County, arcs through the north central portion of Group is overlain by the Oligocene Marianna and the county, and joins the Ochlockonee River Suwannee Limestones.
southeast of Hosford.
Oligocene Series
GEOLOGY Marianna Limestone

Liberty County is underlain by hundreds of feet The Marianna Limestone (Matson and Clapp, of marine limestones, dolomites, sands, and clays. 1909) consists of gray to very light orange, chalky, The oldest rocks recovered from deep oil test well fossiliferous marine limestone frequently containing drilling in this county were Paleozoic Erathem (570 large, coin-shaped Lepidocyclina foraminifera to 250 million years ago) igneous rocks at depths of fossils. The Marianna Limestone is Lower approximately 12,000 feet below land surface (bls) Oligocene in age (38 to 33 million years old). This (Applegate et al., 1978)). The youngest sediments unit was penetrated by only one core (W-6901) in present in the county are Pleistocene and Holocene northwestern Liberty County, and the extent of its (1.8 million years old to recent) alluvium and occurrence under the county is uncertain due to a marine terrace sands and clays. general lack of well coverage. It probably underlies
The Mesozoic Erathem (250 to 65 million years western Liberty County at depths in excess of 400 ago) and early Cenozoic Erathem (Paleocene and feet bls, but pinches out to the east. The Marianna Eocene Series, 65 to 38 million years ago) rocks Limestone is overlain by sediments of the Upper underlying Liberty County are largely marine Oligocene Suwannee Limestone.
carbonates and interbedded siliciclastics lying at
depths penetrated only by deep oil test wells. Most Suwannee Limestone
water wells in Liberty County draw from Oligocene
and Miocene (38 to 5 million years old) strata at The Suwannee Limestone (Cooke and depths of 500 feet or less bls. One deep municipal Mansfield, 1936) is an Upper Oligocene (33 to 25 well taps Eocene (40 to 38 million years ago) million years old) light gray to yellowish-gray, well
limestone. These rocks function as important indurated, often dolomitized marine limestone. It freshwater aquifers for the region. For the typically contains abundant fossils including
purposes of this report, the discussion of the foraminifera, mollusks and echinoids. Depth to the stratigraphy of Liberty County will be limited to Suwannee Limestone ranges between about 350 and these Eocene and younger sediments. Figure 1 450 feet bls. Thickness of the unit is variable, and
shows the geologic cross section locations, and usually exceeds 100 feet. It generally dips and Figures 2 and 3 illustrate the shallow stratigraphy of thickens to the southwest into the trough of the Liberty County. Most of the geologic data cited in Apalachicola Embayment. The Suwannee this study is taken from Schmidt (1984), Puri and Limestone is a component of the Floridan aquifer Vernon,(1964), and from Florida Geological Survey system. It unconformibly overlies the Oligocene well log files. Marianna Limestone, where present, or Eocene
Ocala Group carbonates. The Suwannee Limestone
Eocene Series is overlain by Miocene sediments of the
Ocala Group Chattahoochee, St. Marks, or Chipola Formations,
or by Bruce Creek Limestone.
The Ocala Group (Puri, 1957) comprises a
series of Upper Eocene (41 to 38 million years old) Miocene and Pliocene Series
marine limestone units which underlie most of Chattahoochee and St. Marks Formations
Florida. In Liberty County, sediments of the Ocala
Group are typically white to very pale orange, The Lower Miocene (25 to 20 million years old)
slightly dolomitic, highly microfossiliferous Chattahoochee and St. Marks Formations (Dali and calcarenitic limestone. It is highly porous, and an Stanley-Brown, 1894; Finch, 1823) overlie the important component of. the Floridan aquifer Suwannee. Limestone in Liberty County. The
system. The Ocala Group was penetrated at a



3.











A A'





-300



So'200 CJ)cc

100

01 0 Mu





*g* -200 c

O0O 4- 0
31- 1 11.1 A vo






-10 w
-H rZA1 AC-SA .-R,,A,',O,









-12:1-400 MILIS
0 1 2 3 4 5
- 40
-o0 KILOMETERS
VaERICAL EAGOGINATION IS APPROXIMATILY ITS TIMES TRUE SCALE


Figure 2: Geologic cross section A-A'.






B I A B'






20

0 e MS.

-20

-40
-40 -200X1So 0



-SO.
-a -2T RESTA FORMATION






-100

-120 -E00

40 swAlE 0 2 S

0 2 4 6 9.
VERTICAL EXAGGERATION IS APPROXIMATELY ITS TIMES TRUE SCALE. KILOMETERS



Figure 3: Geologic cross section B-B'.




4.









Chattahoochee Formation is generally a very pale
orange to white or light gray, often quartz sandy, Hawthorn Group
phosphoritic, dolomitic marine limestone. It occurs Torreya Formation
under northern and western Liberty County. The
age-equivalent St. Marks Formation is a white to The Lower Miocene Torreya Formation (Banks
cream, fossiliferous calcilutite limestone underlying and Hunter, 1973; Huddlestun and Hunter, 1982; the southern and eastern portions of the county. Scott, 1988) of the Hawthorn Group underlies The two units interfinger in north-central Liberty northern Liberty County, extending from Leon County (Schmidt, 1984). County westward to Rock Bluff on the Apalachicola
In some cases, post-depositional ground-water River. In Liberty County, the Torreya Formation is alteration of the carbonates in portions of the typically a siliclastic unit consisting of light gray to central and western panhandle has made pale orange quartz sands and clays, commonly
differentiation of the Chattahoochee and St. Marks containing variable'amounts of phosphorite. The Formations from the underlying Suwannee lower portion of the unit is commonly comprised
Limestone and overlying Bruce Creek Limestone of a light olive gray, sandy, phosphoritic, and locally
difficult or impossible. Where defineable in Liberty dolomitic limestone. Depth to the top of this County however, the top of the Chattahoochee/St. formation in Liberty County varies considerably, Marks Formations varies from about 75 feet to 200 ranging from about 10 feet to 100 feet bls. The feet bis. Thickness averages about 200 feet. As thickness of the unit is also highly variable, reaching with the underlying Suwannee Limestone, the 100 to 200 feet thick in the northeastern portion of
Chattahoochee and St. Marks Formations dip to the the county. The Torreya Formation is west-southwest, grading into or interfingering with unconformibly overlain by sediments of the the Bruce Creek Limestone along the southern edge Intracoastal or Jackson Bluff Formations. of Liberty County. The Chattahoochee and St.
Marks Formations are units of the Floridan aquifer Bruce Creek Limestone
system, and many rural Liberty County wells draw
from these formations. Along the southern edge of The Middle Miocene (17 to 10 million years the county, the Bruce Creek Limestone overlies or old) Bruce Creek Limestone (Huddlestun, 1984) is grades into the Chattahoochee and St. Marks a white to yellowish-gray, fossiliferous, calcarenitic,
Formations. In northernmost Liberty County, the marine limestone underlying most of central and Bruce Creek Limestone is absent, and the southern Liberty County. It is often highly
Chattahoochee Formation is overlain by sediments microfossiliferous, molluskan moldic, and in some of the Miocene Chipola Formation or Torreya areas, dolomitic. From north-central Liberty
Formation. County, this unit thickens and dips rapidly towards
the south, into the trough of the Apalachicola
Chipola Formation Embayment. The Bruce Creek Limestone varies in
depth from approximately 125 feet bis at its
The Chipola Formation (Burns, 1889) is a northern limit in central Liberty County to over 200
Lower Miocene carbonate unit underlying portions feet bis in the southern portion of the county. Its of northernmost Liberty County. It is typically thickness increases rapidly from zero in the central comprised of a yellowish-gray to light gray, part of the county southward to about 200 feet near
comprised yellisate-gqart sangy, mariy' the Liberty-Franklin county line. The Bruce Creek
moderately-to-well indurated, quartz sandy, marine Limestone is the uppermost unit of the Floridan limestone. It is exposed as the basal unit at Alum aquifer system in Liberty County. It is overlain by Bluff, north of Bristol on the Apalachicola River. sediments of the Intracoastal, Chipola, or Torreya Here it commonly contains abundant fossil Formations.
mollusks. The Chipola Formation varies between
about 60 and 200 feet bls in Liberty County, and Intracoastal Formation
reaches a maximum of about 50 feet thick. It is
overlain by sediments of the Middle Miocene The Intracoastal Formation (Huddlestun, 1984;
Torreya Formation or the Upper Pliocene Jackson Schmidt and Clark, 1980) is comprised of a Bluff Formation. yellowish-gray, abundantly microfossiliferous, sandy,
poorly-indurated, marine limestone. It spans an age
range of Middle Miocene to Late Pliocene (17 to 2



5.








million years old), with the Late Miocene and Early Pilo-Pleistocene and Holocene Series
Pliocene portions absent due to a hiatus. Like the Undifferentiated Sand and Clays
underlying Bruce Creek Limestone, the updip limit
of the Intracoastal Formation occurs along a west- Much of central and southern Liberty County is
to-east line under northern Liberty County. The covered by surficial quartz sands, clays, clayey sands,
formation is generally absent north of the town of and gravels. Due to the massive and discontinuous Hosford. It thickens and dips to the south- nature of many of these units, they are lumped
southwest, approaching 100 feet in thickness in the together as undifferentiated deposits. These southeastern corner of the county. Depth to the top deposits represent a mixture of marine and fluvial of the unit in Liberty County is highly variable, siliciclastics associated with Pleistocene (1.8 million generally ranging between 50 and 150 feet bis. The to 10,000 years old) sea level highstands and the Intracoastal Formation is locally overlain by prograding Apalachicola delta. The modern soil
sediments of the Chipola, Torreya, or Jackson Bluff profiles probably evolved during the Late Formations. Pleistocene and Holocene (10,000 years ago to
present). Holocene alluvium, in the form of riverPliocene Series borne clays and quartz sand and gravel, is deposited
Jackson Bluff Formation along the banks and bars of the Apalachicola and
Ochlockonee Rivers, which border Liberty County.
The Upper Pliocene (3 to 1.8 million years old)
Jackson Bluff Formation (Puri and Vernon, 1964) is GROUND WATER
predominantly comprised of light gray to olive gray,
poorly-consolidated, clayey quartz sands and sandy Ground water is water that fills the pore spaces
shell beds. It overlies the Chipola, Torreya, and in subsurface rocks and sediments. This water is Intracoastal Formations in Liberty County. The derived principally from precipitation within Liberty
Jackson Bluff Formation is a thin unit, attaining a and adjacent counties. The bulk of Liberty County's maximum thickness of about 30 feet thick in consumptive water is withdrawn from ground water
western Liberty County. Depth to the top of the aquifers. Three main aquifers are present under Jackson Bluff is variable throughout the county, Liberty County. In order of increasing depth, these ranging from 20 to 100 feet bls. It crops out locally are the surficial aquifer system, the intermediate at Alum Bluff along the Apalachicola River. In aquifer and confining system, and the Floridan
northern Liberty County, it is overlain by the aquifer system. Data on aquifer extent and
Citronelle Formation and undifferentiated thicknesses are taken from Scott et al., 1991 (in
sediments. In the southern part of the county, it is preparation). covered by undifferentiated sands and clays.
Surficial aquifer system
Citronelle Formation
The surficial aquifer system is the uppermost
The reddish, clayey, coarse quartz sands and freshwater aquifer in Liberty County. This nongravels of the Upper Pliocene Citronelle Formation artesian aquifer is largely contained within the (Matson, 1916) blanket the Tallahassee Hills in undifferentiated sands and the Citronelle Formation northernmost Liberty County. Believed to be of sediments. It is present under most of Liberty
fluvial origin, the characteristic Citronelle Formation County, reaching a maximum measured thickness of sediments are comprised of cross-bedded sands, about 118 feet in the north-central part of the
gravels, and clays. Portions of the Liberty County county. In central and southern Liberty County it surficial deposits may represent reworked and is highly variable in thickness, ranging from about
redeposited Citronelle sediments, transported from 20 to 70 feet thick. The surficial aquifer system is the eroding highlands to the north. Thickness unconfined, and its upper surface is the water table.
generally varies between 20 and. 80 feet, and the In general, the water-table elevation fluctuates with Citronelle deposits comprise the surficial sediments precipitation rate and conforms to the topography in their area of occurence. Within Liberty County, of the land surface. Recharge to the aquifer is the Citronelle Formation sediments grade laterally largely through rainfall percolating through the southward into a series of undifferentiated quartz loose surficial sediments, and to a lesser extent, by sands and clayey sands. upward seepage from the underlying intermediate
aquifer system. The surficial aquifer system is not



6.









used extensively as a water source in the county.
Sand and gravel
Intermediate aquifer system or confining unit
Pleistocene marine terrace sands and alluvium
The intermediate aquifer system underlies the and Pliocene Citronelle Formation sediments are surficial aquifer system in Liberty County, and is comprised of quartz sand with varying amounts of largely contained within the Torreya, Intracoastal, clay matrix. These deposits blanket much of. the Chipola and Jackson Bluff Formations. Permeable county. A number of shallow private pits in Liberty
beds within the intermediate aquifer system vary County are worked for locally-used fill sand. In considerably in thickness over the areal extent of addition, the U.S. Forest Service routinely digs the aquifer. In general, the aquifer ranges from 100 clayey sand for use in stabilizing forest roads in to 200 feet in thickness under Liberty County, southern Liberty County (Patterson et al., 1986).
corresponding to the variable thicknesses of the None of this sand is utilized commercially. geologic formations containing it. The top of the Patterson et al. (1986) report a quartz sand and
intermediate is also highly variable, ranging from gravel stratum lying at a depth of about 15 feet surface outcrop along rivers and creeks in below the Apalachicola National Forest in southern
northeastern and northwestern Liberty County, to Liberty County. Although this deposit is of 20 feet or less bis at the southern edge of the commercial quality, its remote location and the
county, to as much as 100 feet bis under the thinness of the deposit (about 13 feet thick)
Tallahassee Hills in the .northernmost tip of the preclude commercial mining. In addition, sand and county. Some rural wells draw from this unit, but gravel products are produced more economically in the intermediate aquifer system is not widely used. other parts of the Florida panhandle, thus lessening as a potable water source in this area. Low- the potential for large-scale mining in Liberty
permeability beds in the basal intermediate aquifer County. system may locally function as confining units to the
underlying Floridan aquifer system. Clay

Floridan aquifer system Localized deposits of clay and sandy clay are
also associated with the undifferentiated Pleistocene
The Floridan aquifer system is comprised of and Holocene marine terrace deposits, Holocene
hundreds of feet of Eocene through Miocene age alluvium, and Citronelle Formation sediments.
marine limestones, including the Ocala Group, the Most of these clays are contained in and Marianna and Suwannee Limestones, and where interbedded with other sediments, and as a result
present, the Chattahoochee Formation, St. Marks are relatively impure. Miocene age palygorskite
Formation and Bruce Creek Limestone. Depth to (attapulgite) fuller's earth clays are mined to the
the top of the Floridan aquifer system varies from north in Gadsden County, but no commercial-grade about 50 feet bIs at the southern edge of the county deposits are known in Liberty County. to nearly 200 feet in the west-central portion. It is Flood-plain clay deposits along the the principle source of drinking water in Liberty Apalachicola and Ochlockonee Rivers have been County. The Floridan aquifer system occurs as an utilized for brick-making in nearby Calhoun and artesian aquifer under the entire county. Surface Gadsden Counties (Bell, 1924). Bell (1924) tested springs issuing from this aquifer are absent in clays collected at Estiffanulga Bluff, on the
Liberty County. Most of the regional recharge Apalachicola River in Liberty County, for firing and
occurs further to the north in Jackson County where working properties. He concluded that the clay was the strata comprising the Floridan aquifer system suitable for common brick, hollow block ware, drain crop out at the surface. tile, and earthenware. Commercial exploitation
never occurred.
MINERAL RESOURCES Patterson et al. (1986) noted the presence of a
sandy, shelly, plastic clay in a test boring in southern
The principal mineral resources occurring in Liberty County in the Apalachicola National Forest.
Liberty County are sand and gravel, clay, limestone, The sand and shell impurities, as well as the remote peat, phosphate, heavy minerals, and petroleum. location of the deposit preclude economic mining.
The following discussion summarizes the current Reserve estimates of the clay deposits in Liberty
mining potential of each commodity in the county. County have not been made. Future exploitation



7.








will be largely dependent upon local market potential of the deposits. Therefore, future mining
demand. potential is low.
Limestone
Petroleum
Impure Miocene limestones occur at depth
under most of Liberty County. Most of the Petroleum is produced from the Jurassic-age
shallower units contain extensive impurities, Smackover Formation and Norphiet Sandstone west including quartz sand. Due to the presence of these of Liberty County in the Jay trend of Santa Rosa impurities, the overburden thickness (at least 50 County. These formations are- also present under feet), and the presence of easily-accessible limestone Liberty County, but four oil wells drilled in the deposits at the surface in nearby Jackson County, it county to test these strata were dry holes is unlikely that limestone will ever be an economical (Applegate et al., 1978; Patterson et al., 1986). commodity in Liberty County. While the prospects for commercial petroleum
production in Liberty County appear slim at Peat present, only continued exploration of the Jurassic
and older units will ultimately rule out the potential Peat deposits form in a wet, reducing for the discovery of oil and gas under the county.
environment when accumulation of organic
materials (vegetation) exceeds the decomposition REFERENCES
rate of that material (Bond et al., 1986). While
such conditions are common in the swampy bays Applegate, A.V., Pontigo, F.A., and Rooke, J.H., covering much of the Apalachicola National Forest 1978, Jurassic Smackover oil prospects in
in southern Liberty County, only thin layers of non- the Apalachicola Embayment: Oil and Gas
commercial peaty material (organic deposits Journal, v. 76, no. 4, p. 80-84.
containing more than 25% ash) are present
(Patterson et al., 1986). Banks, J.E., and Hunter, M.E., 1973, Post-Tampa,
Pre-Chipola sediments exposed in Liberty,
Phosphate Gadsden, Leon, and Wakulla Counties,
Florida: Transactions, Gulf Coast
Many of the Miocene and Pliocene formations Association of Geological Societies, v.23, p.
underlying Liberty County contain variable 355-363.
percentages of phosphate sand and granules.
Patterson et al. (1986) reported the phosphate Bell, 0., 1924, A preliminary report on the clays of content of sediments from test- borings in southern Florida (exclusive of Fuller's Earth): in:
Liberty County and adjacent counties to be well Florida Geological Survey 15th Annual
below the minimum commercial percentage. In Report, p. 125-127.
addition, most phosphate-bearing strata occur at
depths in excess of 50 feet. These factors preclude Bond, P., Campbell, K.M., and Scott, T.M., 1986, a high mining potential for phosphate in Calhoun An overview of peat in Florida and related
County. issues: Florida Geological Survey
Special Publication 27, 151 p.
Heavy minerals
Burns, Frank, 1889, Unpublished Field Notes, U.S. Heavy minerals such as rutile, ilmenite, zircon, Geological Survey (Referenced in Cooke
staurolite, and others are minor components of the and Mossom, 1929, Geology of Florida:
surficial and near-surface sediments in Liberty Florida Geological Survey 20th Annual
County. Although a county-wide study has not been Report, 103 p.)
conducted, Patterson et al. (1986) determined the
heavy- mineral concentrations in test borings in Cooke, C.W., 1939, Scenery of Florida interpreted southern Liberty County were significantly below by a geologist: Florida Geological Survey
the commercial minimum percentage. In addition, Bulletin 17, 118 p.
the wide range of mineral species present rather
than specific concentration of the more valuable and Mossom, S., 1929, Geology of
mineral types further reduces the economic Florida: Florida Geological Survey



8.









20th Annual Report, 1927-1928, p. 29-227. Puri, H.S., 1957, Stratigraphy and zonation of the Ocala Group: Florida Geological Survey
and Mansfield, W., 1936, Suwannee Bulletin 38, 248 p.
Limestone of Florida: [abs.] Geological
Society of America Proceedings, and Vernon, R.O., 1964, Summary of
1935, p.71-72. the geology of Florida and a guidebook to
the classic exposures: Florida Geological
DalI, W.H., and Stanley-Brown, J., 1894, Cenozoic Survey Special Publication no. 5 (revised),
geology along the Apalacicola River: 312 p.
Bulletin of the Geological Society of
America, v. 5, p. 147-170. Schmidt, W., 1983, Cenozoic geology of the
Apalachicola River Area, Northwest
Davis, J.H., 1946, The peat deposits of Florida, their Florida: in: Cenozoic geology of the
occurence, development, and uses: Florida Apalachicola River area, northwest Florida:
Geological Survey Bulletin 30, 250 p. Southeastern GeologicalSociety Guidebook
No. 25, October 8, 1983, p. 33.
Finch, J., 1823, Geological essay on the Tertiary
formation in America: American Journal of 1984, Neogene stratigraphy and
Science, v. 7, p. 31-43. geologic history of the Apalachicola
Embayment, Florida: Florida Geological
Huddlestun, P.F., 1984, The Neogene stratigraphy of Survey Bulletin 58, 146 p.
the central Florida Panhandle: [Ph.D
Dissertation], Florida State University, and Clark, M.W., 1980, Geology of
Tallahassee, 210 p. Bay County, Florida: Florida Geological
Survey Bulletin 57, 76 p.
and Hunter, M.E., 1982,
Stratigraphic revision of the Torreya Scott, T.M., 1988, The lithostratigraphy of the
Formation of Florida (abstract) in: Scott, Hawthorn Group (Miocene) of Florida:
T.M., and Upchurch, S., (eds.), Miocene Florida Geological Survey Bulletin 59,
Symposium of the southeastern United 148 p.
States: Florida Bureau of Geology Special
Publication 25, p. 210. Lloyd, J., and Maddox, G., 1991 (in
preparation), Florida's ground water
Johnson, R.A., 1989, Geologic descriptions of monitoring network, Volume 1:
selected exposures in Florida: Florida Introduction and hydrogeologic framework:
Geological Survey Special Publication 30, p. Florida Geological Survey Special
67. Publication no. 32.

Matson, G., and Clapp, F., 1909, A preliminary Sellards, E.H., and Gunter, H., 1918, Geology
report on the geology of Florida with between the Apalachicola and Ochlockonee
special reference to the stratigraphy: Rivers: Florida Geological Survey
Florida Geological Survey 2nd Annual 10th Annual Report, p. 27.
Report, 1908-1909, p. 25-173.
White, W., Puri, H., and Vernon, R., 1964, 1916, The Pliocene Citronelle Unpublished manuscript cited in: Puri, H.
Formation of the Gulf Coastal Plain: U.S. and Vernon, R., 1964, Summary of the
Geological Survey Professional Paper 98, p. geology of Florida and a guidebook to the
167-192. classic exposures: Florida Geological Survey
Special Publication no. 5 (revised), 312 p.
Patterson,, S.H., Cameron, C.C., and Schmidt, W.,
1986, Geology and mineral resource 1970, The geomorphology of the
potential of seven roadless areas in the Florida peninsula: Florida Geological
Apalachicola National Forest, Liberty Survey Bulletin 51, 164 p.
County, Florida: U.S. Geological Survey
Bulletin 1587, 21 p.




9.




Full Text
xml version 1.0 encoding UTF-8
REPORT xmlns http:www.fcla.edudlsmddaitss xmlns:xsi http:www.w3.org2001XMLSchema-instance xsi:schemaLocation http:www.fcla.edudlsmddaitssdaitssReport.xsd
INGEST IEID E95EL7SDL_6BWUNQ INGEST_TIME 2017-04-19T18:50:07Z PACKAGE UF00001042_00001
AGREEMENT_INFO ACCOUNT UF PROJECT UFDC
FILES



PAGE 1

STATE OF FLORIDA DEPARTMENT OF NATURAL RESOURCES S Tom Gardner, Executive Director DIVISION OF RESOURCE MANAGEMENT Jeremy A. Craft, Director FLORIDA GEOLOGICAL SURVEY Walter Schmidt, State Geologist and Chief OPEN FILE REPORT NO. 43 THE GEOMORPHOLOGY AND GEOLOGY OF LIBERTY COUNTY, FLORIDA BY Frank R. Rupert aS' 7 5F LFMISDA LIBRARIES FLORIDA GEOLOGICAL SURVEY Tallahassee 1991

PAGE 2

L I DA Y

PAGE 3

The geomorphology and geology of Liberty County, Florida Frank R. Rupert, P.G. No. 149 GEOMORPHOLOGY characterized by a generally flat and often swampy, seaward-sloping, sandy plain. Most of the lowlands Liberty County is situated in the Northern Zone area is ancient marine terrace, shaped by highgeomorphic province of White (1970), which standing Pleistocene seas. Today, much of southern includes the northern Florida peninsula and all of Liberty County is covered by shallow, denslythe panhandle. In this portion of the east-central wooded swamp-like areas called "bays", and poorlyFlorida panhandle, the Northern Zone is divided defined creeks. Elevations in the Gulf Coastal into four geomorphic subzones based primarily on Lowlands of Liberty County range from between 20 topographic elevations. These include the Gulf and 25 feet above mean sea level (MSL) at the Coastal Lowlands, Beacon Slope, the Tallahassee southern end of the county to approximately 100 Hills, and the River Valley Lowlands (Figure 1). feet above MSL where the lowlands meet the higher The Gulf Coastal Lowlands comprise much of slopes in northern Liberty County. southern Liberty County. This subzone is An elevationally-transistional gemorphic zone JACKSON CO., N -74 O661 Oo / <: -EXPLANATION s (a 9. STATEICOUNTY ROAD a1' 0 CORE o o s CROSS SECTION LOCATION --. -TALLAHASSEE HILLS BEACON SLOPE [ GULF COASTAL LOWLANDS S\APALACHICOLA RIVER -.: VALLEY LOWLANDS SW-19 fOCHLOCKONEE RIVER SW-49 ' VALLEY LOWLANDS ' , -iCODY SCARP MILES ." 0 2 4 48 KILOMETERS 0SUMKTRAT co FRANKLIN. Co. A' W-14890 Figure 1: Geomorphic and cross section location map of Liberty County. 1.

PAGE 4

named the Beacon Slope (White et al., 1964) The river bluffs are commonly dissected by a separates the Gulf Coastal Lowlands from the series of deep, east-west trending ravines containing siliciclastic hills of northern Liberty County. The small creeks which drain into the Apalachicola Beacon Slope is a uniformly-sloping, ramp-like River. Many of these ravines extend several miles feature linking the topographically higher east of the river, ending at so-called "steepheads" Tallahassee Hills on the north with the Gulf Coastal (Sellards and Gunter, 1918). Steepheads form from Lowlands, Near-surface sediments are largely lateral undercutting of the sandy surficial sediments siliclastics overlying karstic limestone. Swampy by water seeping out of the surficial aquifer system. depressions and cover-subsidence sinks are common Ground water percolates downward through the throughout this terrain. In Liberty County, surficial sediments until it encounters a clay or marl. elevations range from about 100 feet MSL at the It then travels horizontally over the less permeable southern edge of the slope to approximately 200 strata and emerges as a small spring or seep at a feet MSL at the northern edge, where it adjoins the bluff face. Gradually, the flowing water undermines Cody Scarp. The origin of the Beacon Slope is the overburden material, which slumps off forming uncertain, but it is most likely an erosional feature a semicircular, steep-walled head. As undermining associated with the higher sea level stands of the and slumping continue through time, the steephead Pleistocene. migrates laterally away from the original bluff face, A relict southward facing marine escapment cutting a ravine as it progresses. Other steepheads named the Cody Scarp (Puri and Vernon, 1964) may branch off from the original ravine, forming a forms the boundary between the Beacon Slope and dendritic series of smaller ravines feeding the parent the topographically higher Tallahssee Hills in ravine. northernmost Liberty County. This feature spans The Apalachicola and Ochlockonee Rivers are much of northern Florida, and is one of the most the major streams flowing in Liberty County. The persistant topographic breaks in the state. The Apalachicola River forms the western county Cody Scarp has been erosionally obscured in most boundary with adjacent Calhoun County. In of northern Liberty County. In the northeastern northwestern Liberty County, the broad valley of the part of the county, the scarp rises from a toe Apachicola averages 50 feet MSL in elevation. The elevation of approximately 205 feet MSL to a crest river meanders southwestward through a three-mile of about 220 feet MSL, marking the southern extent wide valley, which gradually descends to an of the Tallahassee Hills geomorphic zone. elevation of about 25 feet MSL at the southern edge The Tallahassee Hills (Cooke, 1939) are a series of Liberty County. Here, the valley coalesces into of topographic highlands spanning the northern the swampy terrain of the Gulf Coastal Lowlands. edge of the eastern Florida panhandle. They are The valley comprises a geomorphic subzone named part of the Northern Highlands geomorphic the Apalachicola River Valley Lowlands. province, which is thought to be a stream-dissected The Ochlockonee River forms the eastern remnant of a once continous highland plain Liberty County boundary with Leon and Wakulla spanning southern Georgia and northern Florida. Counties. Originating in Georgia, the river is The Tallahassee Hills are capped by deltaic to dammed as a hydroelectric power source just above shallow marine, clayey sands, silts and clays. Highway 20 in Leon County, forming Lake Talquin. Elevations of the hills within Liberty County vary South of the dam, the Ochlockonee meanders over from approximately 220 feet MSL at the crest of the a broad, swampy valley averaging about one mile Cody Scarp to nearly 250 feet MSL at the northern wide. This valley comprises the Ochlockonee River county boundary. The modern hilly topography is Valley Lowlands geomorphic zone. In northeastern the result of post-depositional dissection and erosion Liberty County, the river valley is approximately 40 by running water. Steep bluffs occur in feet above MSL. Numerous small creeks contribute northwestern Liberty County, where the Tallahassee to the river along its course, and oxbow lakes are Hills end abruptly at the floodplain of the common along the northern stretch of the river. In Apalachicola River. The bluffs commonly stand 150 southeastern Liberty County, .the valley broadens feet or more above the floor of the floodplain, considerablly, merging with the low swampy "bays" exposing Miocene to Holocene age strata. Alum of the Apalachicola National Forest. Elevations Bluff, located about 2.5 miles northwest of Bristol here average about 10 feet above MSL. The on the Apalachicola River, is one of the best Ochlockonee empties into Apalachee Bay, southeast geologic exposures in Florida (Schmidt, 1983; of Liberty County. Johnson, 1989). A number of small creeks drain the flat, 2.

PAGE 5

swampy terrain of central Liberty County, and depth of 660 feet bls in one municipal water well in empty into the Apalchicola and Ochlockonee Rivers. the city of Bristol. Because this unit lies in excess Telogia Creek is the largest of these; it enters of 600 feet bls countywide, it is not used extensively northeastern Liberty County from adjacent Gadsden as a water source in Liberty County. The Ocala County, arcs through the north central portion of Group is overlain by the Oligocene Marianna and the county, and joins the Ochlockonee River Suwannee Limestones. southeast of Hosford. Oligocene Series GEOLOGY Marianna Limestone Liberty County is underlain by hundreds of feet The Marianna Limestone (Matson and Clapp, of marine limestones, dolomites, sands, and clays. 1909) consists of gray to very light orange, chalky, The oldest rocks recovered from deep oil test well fossiliferous marine limestone frequently containing drilling in this county were Paleozoic Erathem (570 large, coin-shaped Lepidocyclina foraminifera to 250 million years ago) igneous rocks at depths of fossils. The Marianna Limestone is Lower approximately 12,000 feet below land surface (bls) Oligocene in age (38 to 33 million years old). This (Applegate et al., 1978)). The youngest sediments unit was penetrated by only one core (W-6901) in present in the county are Pleistocene and Holocene northwestern Liberty County, and the extent of its (1.8 million years old to recent) alluvium and occurrence under the county is uncertain due to a marine terrace sands and clays, general lack of well coverage. It probably underlies The Mesozoic Erathem (250 to 65 million years western Liberty County at depths in excess of 400 ago) and early Cenozoic Erathem (Paleocene and feet bls, but pinches out to the east. The Marianna Eocene Series, 65 to 38 million years ago) rocks Limestone is overlain by sediments of the Upper underlying Liberty County are largely marine Oligocene Suwannee Limestone. carbonates and interbedded siliciclastics lying at depths penetrated only by deep oil test wells. Most Suwannee Limestone water wells in Liberty County draw from Oligocene and Miocene (38 to 5 million years old) strata at The Suwannee Limestone (Cooke and depths of 500 feet or less bls. One deep municipal Mansfield, 1936) is an Upper Oligocene (33 to 25 well taps Eocene (40 to 38 million years ago) million years old) light gray to yellowish-gray, well limestone. These rocks function as important indurated, often dolomitized marine limestone. It freshwater aquifers for the region. For the typically contains abundant fossils including purposes of this report, the discussion of the foraminifera, mollusks and echinoids. Depth to the stratigraphy of Liberty County will be limited to Suwannee Limestone ranges between about 350 and these Eocene and younger sediments. Figure 1 450 feet bls. Thickness of the unit is variable, and shows the geologic cross section locations, and usually exceeds 100 feet. It generally dips and Figures 2 and 3 illustrate the shallow stratigraphy of thickens to the southwest into the trough of the Liberty County. Most of the geologic data cited in Apalachicola Embayment. The Suwannee this study is taken from Schmidt (1984), Puri and Limestone is a component of the Floridan aquifer Vernon,(1964), and from Florida Geological Survey system. It unconformibly overlies the Oligocene well log files. Marianna Limestone, where present, or Eocene Ocala Group carbonates. The Suwannee Limestone Eocene Series is overlain by Miocene sediments of the Ocala Group Chattahoochee, St. Marks, or Chipola Formations, or by Bruce Creek Limestone. The Ocala Group (Puri, 1957) comprises a series of Upper Eocene (41 to 38 million years old) Miocene and Pliocene Series marine limestone units which underlie most of Chattahoochee and St. Marks Formations Florida. In Liberty County, sediments of the Ocala Group are typically white to very pale orange, The Lower Miocene (25 to 20 million years old) slightly dolomitic, highly microfossiliferous Chattahoochee and St. Marks Formations (Dall and calcarenitic limestone. It is highly porous, and an Stanley-Brown, 1894; Finch, 1823) overlie the important component of the Floridan aquifer Suwannee. Limestone in Liberty County. The system. The Ocala Group was penetrated at a 3.

PAGE 6

A A' C t N.NE 200 -1 2400 MILES w, 01 34 0 0 M4 S'I I I -2-v LA -12400 M' "0 1 4 5 | -500 KILOMETERS VEaRICAL 1IAGOIRATION IS APPROXIMATILY ITS TIMES TRUE SCALE Figure 2: Geologic cross section A-A'. B I A B' asa -2 0 -.--Roo RYA FORMATION .:of XMESTOE ESWAN o i MILEs -100 1 2I l l -o0 2 4 6 o VERTICAL EXAGGERATION IS APPROXIMATELY IS TIMES TRUE SCALE. KILOMETERS Figure 3: Geologic cross section B-B'. 4. 4.

PAGE 7

Chattahoochee Formation is generally a very pale orange to white or light gray, often quartz sandy, Hawthorn Group phosphoritic, dolomitic marine limestone. It occurs Torreya Formation under northern and western Liberty County. The age-equivalent St. Marks Formation is a white to The Lower Miocene Torreya Formation (Banks cream, fossiliferous calcilutite limestone underlying and Hunter, 1973; Huddlestun and Hunter, 1982; the southern and eastern portions of the county. Scott, 1988) of the Hawthorn Group underlies The two units interfinger in north-central Liberty northern Liberty County, extending from Leon County (Schmidt, 1984). County westward to Rock Bluff on the Apalachicola In some cases, post-depositional ground-water River. In Liberty County, the Torreya Formation is alteration of the carbonates in portions of the typically a siliclastic unit consisting of light gray to central and western panhandle has made pale orange quartz sands and clays, commonly differentiation of the Chattahoochee and St. Marks containing variable amounts of phosphorite. The Formations from the underlying Suwannee lower portion of the unit is commonly comprised Limestone and overlying Bruce Creek Limestone of a light olive gray, sandy, phosphoritic, and locally difficult or impossible. Where defineable in Liberty dolomitic limestone. Depth to the top of this County however, the top of the Chattahoochee/St. formation in Liberty County varies considerably, Marks Formations varies from about 75 feet to 200 ranging from about 10 feet to 100 feet bls. The feet bls. Thickness averages about 200 feet. As thickness of the unit is also highly variable, reaching with the underlying Suwannee Limestone, the 100 to 200 feet thick in the northeastern portion of Chattahoochee and St. Marks Formations dip to the the county. The Torreya Formation is west-southwest, grading into or interfingering with unconformibly overlain by sediments of the the Bruce Creek Limestone along the southern edge Intracoastal or Jackson Bluff Formations. of Liberty County. The Chattahoochee and St. Marks Formations are units of the Floridan aquifer Bruce Creek Limestone system, and many rural Liberty County wells draw from these formations. Along the southern edge of The Middle Miocene (17 to 10 million years the county, the Bruce Creek Limestone overlies or old) Bruce Creek Limestone (Huddlestun, 1984) is grades into the Chattahoochee and St. Marks a white to yellowish-gray, fossiliferous, calcarenitic, Formations. In northernmost Liberty County, the marine limestone underlying most of central and Bruce Creek Limestone is absent, and the southern Liberty County. It is often highly Chattahoochee Formation is overlain by sediments microfossiliferous, molluskan moldic, and in some of the Miocene Chipola Formation or Torreya areas, dolomitic. From north-central Liberty Formation. County, this unit thickens and dips rapidly towards the south, into the trough of the Apalachicola Chipola Formation Embayment. The Bruce Creek Limestone varies in depth from approximately 125 feet bls at its The Chipola Formation (Burns, 1889) is a northern limit in central Liberty County to over 200 Lower Miocene carbonate unit underlying portions feet bls in the southern portion of the county. Its of northernmost Liberty County. It is typically thickness increases rapidly from zero in the central cy to lt gy, part of the county southward to about 200 feet near comprised of a yellowish-gray to q ight gray, the Liberty-Franklin county line. The Bruce Creek moderately-to-well indurated, quartz sandy, marine Limestone is the uppermost unit of the Floridan limestone. It is exposed as the basal unit at Alum aquifer system in Liberty County. It is overlain by Bluff, north of Bristol on the Apalachicola River. sediments of the Intracoastal, Chipola, or Torreya Here it commonly contains abundant fossil Formations. mollusks. The Chipola Formation varies between about 60 and 200 feet bls in Liberty County, and Intracoastal Formation reaches a maximum of about 50 feet thick. It is overlain by sediments of the Middle Miocene The Intracoastal Formation (Huddlestun, 1984; Torreya Formation or the Upper Pliocene Jackson Schmidt and Clark, 1980) is comprised of a Bluff Formation. yellowish-gray, abundantly microfossiliferous, sandy, poorly-indurated, marine limestone. It spans an age range of Middle Miocene to Late Pliocene (17 to 2 5.

PAGE 8

million years old), with the Late Miocene and Early Pllo-Pleistocene and Holocene Series Pliocene portions absent due to a hiatus. Like the Undifferentiated Sand and Clays underlying Bruce Creek Limestone, the updip limit of the Intracoastal Formation occurs along a westMuch of central and southern Liberty County is to-east line under northern Liberty County. The covered by surficial quartz sands, clays, clayey sands, formation is generally absent north of the town of and gravels. Due to the massive and discontinuous Hosford. It thickens and dips to the southnature of many of these units, they are lumped southwest, approaching 100 feet in thickness in the together as undifferentiated deposits. These southeastern corner of the county. Depth to the top deposits represent a mixture of marine and fluvial of the unit in Liberty County is highly variable, siliciclastics associated with Pleistocene (1.8 million generally ranging between 50 and 150 feet bis. The to 10,000 years old) sea level highstands and the Intracoastal Formation is locally overlain by prograding Apalachicola delta. The modern soil sediments of the Chipola, Torreya, or Jackson Bluff profiles probably evolved during the Late Formations. Pleistocene and Holocene (10,000 years ago to present). Holocene alluvium, in the form of riverPliocene Series borne clays and quartz sand and gravel, is deposited Jackson Bluff Formation along the banks and bars of the Apalachicola and Ochlockonee Rivers, which border Liberty County. The Upper Pliocene (3 to 1.8 million years old) Jackson Bluff Formation (Puri and Vernon, 1964) is GROUND WATER predominantly comprised of light gray to olive gray, poorly-consolidated, clayey quartz sands and sandy Ground water is water that fills the pore spaces shell beds. It overlies the Chipola, Torreya, and in subsurface rocks and sediments. This water is Intracoastal Formations in Liberty County. The derived principally from precipitation within Liberty Jackson Bluff Formation is a thin unit, attaining a and adjacent counties. The bulk of Liberty County's maximum thickness of about 30 feet thick in consumptive water is withdrawn from ground water western Liberty County. Depth to the top of the aquifers. Three main aquifers are present under Jackson Bluff is variable throughout the county, Liberty County. In order of increasing depth, these ranging from 20 to 100 feet bls. It crops out locally are the surficial aquifer system, the intermediate at Alum Bluff along the Apalachicola River. In aquifer and confining system, and the Floridan northern Liberty County, it is overlain by the aquifer system. Data on aquifer extent and Citronelle Formation and undifferentiated thicknesses are taken from Scott et al., 1991 (in sediments. In the southern part of the county, it is preparation). covered by undifferentiated sands and clays. Surficial aquifer system Citronelle Formation The surficial aquifer system is the uppermost The reddish, clayey, coarse quartz sands and freshwater aquifer in Liberty County. This nongravels of the Upper Pliocene Citronelle Formation artesian aquifer is largely contained within the (Matson, 1916) blanket the Tallahassee Hills in undifferentiated sands and the Citronelle Formation northernmost Liberty County. Believed to be of sediments. It is present under most of Liberty fluvial origin, the characteristic Citronelle Formation County, reaching a maximum measured thickness of sediments are comprised of cross-bedded sands, about 118 feet in the north-central part of the gravels, and clays. Portions of the Liberty County county. In central and southern Liberty County it surficial deposits may represent reworked and is highly variable in thickness, ranging from about redeposited Citronelle sediments, transported from 20 to 70 feet thick. The surficial aquifer system is the eroding highlands to the north. Thickness unconfined, and its upper surface is the water table. generally varies between 20 and. 80 feet, and the In general, the water-table elevation fluctuates with Citronelle deposits comprise the surficial sediments precipitation rate and conforms to the topography in their area of occurence. Within Liberty County, of the land surface. Recharge to the aquifer is the Citronelle Formation sediments grade laterally largely through rainfall percolating through the southward into a series of undifferentiated quartz loose surficial sediments, and to a lesser extent, by sands and clayey sands, upward seepage from the underlying intermediate aquifer system. The surficial aquifer system is not 6.

PAGE 9

used extensively as a water source in the county. Sand and gravel Intermediate aquifer system or confining unit Pleistocene marine terrace sands and alluvium The intermediate aquifer system underlies the and Pliocene Citronelle Formation sediments are surficial aquifer system in Liberty County, and is comprised of quartz sand with varying amounts of largely contained within the Torreya, Intracoastal, clay matrix. These deposits blanket much of. the Chipola and Jackson Bluff Formations. Permeable county. A number of shallow private pits in Liberty beds within the intermediate aquifer system vary County are worked for locally-used fill sand. In considerably in thickness over the areal extent of addition, the U.S. Forest Service routinely digs the aquifer. In general, the aquifer ranges from 100 clayey sand for use in stabilizing forest roads in to 200 feet in thickness under Liberty County, southern Liberty County (Patterson et al., 1986). corresponding to the variable thicknesses of the None of this sand is utilized commercially. geologic formations containing it. The top of the Patterson et al. (1986) report a quartz sand and intermediate is also highly variable, ranging from gravel stratum lying at a depth of about 15 feet surface outcrop along rivers and creeks in below the Apalachicola National Forest in southern northeastern and northwestern Liberty County, to Liberty County. Although this deposit is of 20 feet or less bls at the southern edge of the commercial quality, its remote location and the county, to as much as 100 feet bls under the thinness of the deposit (about 13 feet thick) Tallahassee Hills in the.northernmost tip of the preclude commercial mining. In addition, sand and county. Some rural wells draw from this unit, but gravel products are produced more economically in the intermediate aquifer system is not widely used. other parts of the Florida panhandle, thus lessening as a potable water source in this area. Lowthe potential for large-scale mining in Liberty permeability beds in the basal intermediate aquifer County. system may locally function as confining units to the underlying Floridan aquifer system. Clay Floridan aquifer system Localized deposits of clay and sandy clay are also associated with the undifferentiated Pleistocene The Floridan aquifer system is comprised of and Holocene marine terrace deposits, Holocene hundreds of feet of Eocene through Miocene age alluvium, and Citronelle Formation sediments. marine limestones, including the Ocala Group, the Most of these clays are contained in and Marianna and Suwannee Limestones, and where interbedded with other sediments, and as a result present, the Chattahoochee Formation, St. Marks are relatively impure. Miocene age palygorskite Formation and Bruce Creek Limestone. Depth to (attapulgite) fuller's earth clays are mined to the the top of the Floridan aquifer system varies from north in Gadsden County, but no commercial-grade about 50 feet bls at the southern edge of the county deposits are known in Liberty County. to nearly 200 feet in the west-central portion. It is Flood-plain clay deposits along the the principle source of drinking water in Liberty Apalachicola and Ochlockonee Rivers have been County. The Floridan aquifer system occurs as an utilized for brick-making in nearby Calhoun and artesian aquifer under the entire county. Surface Gadsden Counties (Bell, 1924). Bell (1924) tested springs issuing from this aquifer are absent in clays collected at Estiffanulga Bluff, on the Liberty County. Most of the regional recharge Apalachicola River in Liberty County, for firing and occurs further to the north in Jackson County where working properties. He concluded that the clay was the strata comprising the Floridan aquifer system suitable for common brick, hollow block ware, drain crop out at the surface, tile, and earthenware. Commercial exploitation never occurred. MINERAL RESOURCES Patterson et al. (1986) noted the presence of a sandy, shelly, plastic clay in a test boring in southern The principal mineral resources occurring in Liberty County in the Apalachicola National Forest. Liberty County are sand and gravel, clay, limestone, The sand and shell impurities, as well as the remote peat, phosphate, heavy minerals, and petroleum. location of the deposit preclude economic mining. The following discussion summarizes the current Reserve estimates of the clay deposits in Liberty mining potential of each commodity in the county. County have not been made. Future exploitation S7.

PAGE 10

will be largely dependent upon local market potential of the deposits. Therefore, future mining demand. potential is low. Limestone Petroleum Impure Miocene limestones occur at depth under most of Liberty County. Most of the Petroleum is produced from the Jurassic-age shallower units contain extensive impurities, Smackover Formation and Norphiet Sandstone west including quartz sand. Due to the presence of these of Liberty County in the Jay trend of Santa Rosa impurities, the overburden thickness (at least 50 County. These formations are also present under feet), and the presence of easily-accessible limestone Liberty County, but four oil wells drilled in the deposits at the surface in nearby Jackson County, it county to test these strata were dry holes is unlikely that limestone will ever be an economical (Applegate et al., 1978; Patterson et al., 1986). commodity in Liberty County. While the prospects for commercial petroleum production in Liberty County appear slim at Peat present, only continued exploration of the Jurassic and older units will ultimately rule out the potential Peat deposits form in a wet, reducing for the discovery of oil and gas under the county. environment when accumulation of organic materials (vegetation) exceeds the decomposition REFERENCES rate of that material (Bond et al., 1986). While such conditions are common in the swampy bays Applegate, A.V., Pontigo, FA., and Rooke, J.H., covering much of the Apalachicola National Forest 1978, Jurassic Smackover oil prospects in in southern Liberty County, only thin layers of nonthe Apalachicola Embayment: Oil and Gas commercial peaty material (organic deposits Journal, v. 76, no. 4, p. 80-84. containing more than 25% ash) are present (Patterson et al., 1986). Banks, J.E., and Hunter, M.E., 1973, Post-Tampa, Pre-Chipola sediments exposed in Liberty, Phosphate Gadsden, Leon, and Wakulla Counties, Florida: Transactions, Gulf Coast Many of the Miocene and Pliocene formations Association of Geological Societies, v. 23, p. underlying Liberty County contain variable 355-363. percentages of phosphate sand and granules. Patterson et al. (1986) reported the phosphate Bell, 0., 1924, A preliminary report on the clays of content of sediments from test borings in southern Florida (exclusive of Fuller's Earth): n: Liberty County and adjacent counties to be well Florida Geological Survey 15th Annual below the minimum commercial percentage. In Report, p. 125-127. addition, most phosphate-bearing strata occur at depths in excess of 50 feet. These factors preclude Bond, P., Campbell, K.M., and Scott, T.M., 1986, a high mining potential for phosphate in Calhoun An overview of peat in Florida and related County. issues: Florida Geological Survey Special Publication 27, 151 p. Heavy minerals Burns, Frank, 1889, Unpublished Field Notes, U.S. Heavy minerals such as rutile, ilmenite, zircon, Geological Survey (Referenced in Cooke staurolite, and others are minor components of the and Mossom, 1929, Geology of Florida: surficial and near-surface sediments in Liberty Florida Geological Survey 20th Annual County. Although a county-wide study has not been Report, 103 p.) conducted, Patterson et al. (1986) determined the heavymineral concentrations in test borings in Cooke, C.W., 1939, Scenery of Florida interpreted southern Liberty County were significantly below by a geologist: Florida Geological Survey the commercial minimum percentage. In addition, Bulletin 17, 118 p. the wide range of mineral species present rather than specific concentration of the more valuable , and Mossom, S., 1929, Geology of mineral types further reduces the economic Florida: Florida Geological Survey 8. *

PAGE 11

20th Annual Report, 1927-1928, p. 29-227. Puri, H.S., 1957, Stratigraphy and zonation of the Ocala Group: Florida Geological Survey , and Mansfield, W., 1936, Suwannee Bulletin 38, 248 p. Limestone of Florida: [abs.] Geological Society of America Proceedings, , and Vernon, R.O., 1964, Summary of 1935, p.71-72.the geology of Florida and a guidebook to the classic exposures: Florida Geological Dall, W.H., and Stanley-Brown, J., 1894, Cenozoic Survey Special Publication no. 5 (revised), geology along the Apalacicola River: 312 p. Bulletin of the Geological Society of America, v. 5, p. 147-170. Schmidt, W., 1983, Cenozoic geology of the Apalachicola River Area, Northwest Davis, J.H., 1946, The peat deposits of Florida, their Florida: in: Cenozoic geology of the occurence, development, and uses: Florida Apalachicola River area, northwest Florida: Geological Survey Bulletin 30, 250 p. Southeastern GeologicalSociety Guidebook No. 25, October 8, 1983, p. 33. Finch, J., 1823, Geological essay on the Tertiary formation in America: American Journal of , 1984, Neogene stratigraphy and Science, v. 7, p. 31-43. geologic history of the Apalachicola Embayment, Florida: Florida Geological Huddlestun, P.F., 1984, The Neogene stratigraphy of Survey Bulletin 58, 146 p. the central Florida Panhandle: [Ph.D Dissertation], Florida State University, , and Clark, M.W., 1980, Geology of Tallahassee, 210 p. Bay County, Florida: Florida Geological Survey Bulletin 57, 76 p. , and Hunter, M.E., 1982, Stratigraphic revision of the Torreya Scott, T.M., 1988, The lithostratigraphy of the Formation of Florida (abstract) in: Scott, Hawthorn Group (Miocene) of Florida: T.M., and Upchurch, S., (eds.), Miocene Florida Geological Survey Bulletin 59, Symposium of the southeastern United 148 p. States: Florida Bureau of Geology Special Publication 25, p. 210. , Lloyd, J., and Maddox, G., 1991 (in preparation), Florida's ground water Johnson, RA., 1989, Geologic descriptions of monitoring network, Volume 1: selected exposures in Florida: Florida Introduction and hydrogeologic framework: Geological Survey Special Publication 30, p. Florida Geological Survey Special 67. Publication no. 32. Matson, G., and Clapp, F., 1909, A preliminary Sellards, E.H., and Gunter, H., 1918, Geology report on the geology of Florida with between the Apalachicola and Ochlockonee special reference to the stratigraphy: Rivers: Florida Geological Survey Florida Geological Survey 2nd Annual 10th Annual Report, p. 27. Report, 1908-1909, p. 25-173. White, W., Puri, H., and Vernon, R., 1964, , 1916, The Pliocene Citronelle Unpublished manuscript cited in: Puri, H. Formation of the Gulf Coastal Plain: U.S. and Vernon, R., 1964, Summary of the Geological Survey Professional Paper 98, p. geology of Florida and a guidebook to the 167-192. classic exposures: Florida Geological Survey Special Publication no. 5 (revised), 312 p. Patterson,, S.H., Cameron, C.C., and Schmidt, W., 1986, Geology and mineral resource , 1970, The geomorphology of the potential of seven roadless areas in the Florida peninsula: Florida Geological Apalachicola National Forest, Liberty Survey Bulletin 51, 164 p. County, Florida: U.S. Geological Survey Bulletin 1587, 21 p. 9.

PAGE 12

-FLORIDA-GEOLOGICAL-SURVEY COPYRIGHT NOTICE © [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.