FLORIDA GEOLOGICAL SURVEY


siliciclastics with carbonates becoming more abundant in southwestern Florida. The facies
relationships within the marine Pliocene sediments of southern Florida are quite complex.

 Tt Tamiami Formation The Tamiami Formation (Mansfield, 1939) is a poorly defined
lithostratigraphic unit containing a wide range of mixed carbonate-siliciclastic lithologies and
associated faunas (Missimer, 1992). It occurs at or near the land surface in Charlotte, Lee,
Hendry, Collier and Monroe Counties in the southern peninsula. A number of named and
unnamed members are recognized within the Tamiami Formation. These include: the
Buckingham Limestone Member; an unnamed tan clay and sand; an oyster (Hyotissa) facies, a
sand facies, the Ochopee Limestone Member, the Bonita Springs Marl Member; an unnamed
limestone facies; the Golden Gate Reef Member; and the Pinecrest Sand Member (Missimer,
1992). The individual members of the Tamiami Formation were not separately mapped on the
geological map.
 Lithologies of the Tamiami Formation in the mapped area include: 1) light gray to tan,
unconsolidated, fine to coarse grained, fossiliferous sand; 2) light gray to green, poorly
consolidated, fossiliferous sandy clay to clayey sand; 3) light gray, poorly consolidated, very fine
to medium grained, calcareous, fossiliferous sand; 4) white to light gray, poorly consolidated,
sandy, fossiliferous limestone; and 5) white to light gray, moderately to well indurated, sandy,
fossiliferous limestone. Phosphate is present in virtually all lithologies as limited quantities of
sand- to gravel-sized grains. Fossils present in the Tamiami occur as molds, casts and original
material. The fossils present include barnacles, mollusks, corals, echinoids, foraminifers and
calcareous nannoplankton.
 The Tamiami Formation has highly permeable to impermeable lithologies that form a
complex aquifer. Locally, it is part of the surficial aquifer system. In other areas, it forms a part
of the intermediate confining unit/aquifer system.

 Tib Jackson Bluff Formation The Jackson Bluff Formation, named by Vernon and
Puri (1964), occurs at or near the surface in a limited area of the panhandle in Leon, Liberty and
Wakulla Counties. It has attracted much attention due to its abundant fossil molluscan fauna
(Huddlestun, 1984; Schmidt, 1984).
 In the outcrop area, the Jackson Bluff Formation is described as a sandy, clayey shell bed
(Schmidt, 1984). It is composed of tan to orange-brown to gray green, poorly consolidated,
fossiliferous, sandy clays to clayey sands. Fossils present include abundant mollusks, corals,
foraminifers and occasional vertebrate remains.

 Tic Intracoastal Formation Limited exposures and shallow subsurface occurrences of
the Intracoastal Formation have been reported in northwestern Florida (Bay, Franklin, Liberty
and Wakulla Counties) (Schmidt, 1984). In the subsurface, it occurs to the west across the
Apalachicola Embayment (Huddlestun, 1984; Schmidt, 1984).
 The Intracoastal Formation is composed of light gray to olive gray, poorly indurated,
sandy, clayey, highly fossiliferous limestone (grainstone and packstone). The fossils present
include foraminifers, mollusks, barnacles, echinoids and ostracods. Quartz sand varies from
very fine to coarse grained (Huddlestun, 1984).