OPEN FILE REPORT NO. 80


suggested grouping the latest Pliocene through late Pleistocene Caloosahatchee, Bermont and
Fort Thompson Formations in to a single lithostratigraphic entity, the Okeechobee formation
(informal). In mapping the shelly sands and carbonates, a generalized grouping as Tertiary-
Quaternary shell units (TQsu) was utilized. This is equivalent to the informal Okeechobee
formation. The distribution of the Caloosahatchee and Fort Thompson Formation are shown on
previous geologic maps by Cooke (1945), Vernon and Puri (1964) and Brooks (1982).
 The Nashua Formation occurs within the Pliocene Pleistocene in northern Florida.
However, it crops out or is near the surface is an area too small to be shown on a map of this
scale.
 Lithologically these sediments are complex, varying from unconsolidated, variably
calcareous and fossiliferous quartz sands to well indurated, sandy, fossiliferous limestones (both
marine and freshwater). Clayey sands and sandy clays are present. These sediments form part
of the surficial aquifer system

 Pleistocene Series

 Oa Anastasia Formation The Atlantic Coastal Ridge is underlain by the Anastasia
Formation from St. Johns County southward to Palm Beach County. Excellent exposures occur
in Flagler County in Washington Oaks State Park, in Martin County at the House of Refuge on
Hutchinson Island and at Blowing Rocks in Palm Beach County. An impressive exposure of
Anastasia Formation sediments occurs along Country Club Road in Palm Beach County
(Lovejoy, 1992). The Anastasia Formation generally is recognized near the coast but extends
inland as much as 20 miles (32 kilometers) in St. Lucie and Martin Counties.
 The Anastasia Formation, named by Sellards (1912),is composed of interbedded sands
and coquinoid limestones. The most recognized facies of the Anastasia sediments is an orangish
brown, unindurated to moderately indurated, coquina of whole and fragmented mollusk shells in
a matrix of sand often cemented by sparry calcite. Sands occur as light gray to tan and orangish
brown, unconsolidated to moderately indurated, unfossiliferous to very fossiliferous beds. The
Anastasia Formation forms part of the surficial aquifer system.

 Ok Key Largo Limestone The Key Largo Limestone, named by Sanford (1909), is
exposed at the surface in the Florida Keys from Soldier Key on the northeast to Newfound
Harbor Keys near Big Pine Key on the southwest (Hoffmeister, 1974). This unit is a fossil coral
reef much like the present day reefs offshore from the Keys. An exceptional exposure of the
Key Largo Limestone occurs in the Windley Key Quarry State Geological Site in the upper
Florida Keys. Exposures of the limestone containing large coral heads are in a series of old
quarries.
 The Key Largo Limestone is a white to light gray, moderately to well indurated,
fossiliferous, coralline limestone composed of coral heads encased in a calcarenitic matrix. Little
to no siliciclastic sediment is found in these sediments. Fossils present include corals, mollusks
and bryozoans. It is highly porous and permeable and is part of the Biscayne Aquifer of the
surficial aquifer system

 Om Miami Limestone The Miami Limestone (formerly the Miami Oolite), named by
Sanford (1909), occurs at or near the surface in southeastern peninsular Florida from Palm Beach