FLORIDA GEOLOGICAL SURVEY


 Upper Eocene Priabonian Stage

 To Ocala Limestone Dall and Harris (1892) referred to the limestones exposed near
Ocala, Marion County, in central peninsular Florida as the Ocala Limestone. Puri (1953, 1957)
elevated the Ocala Limestone to group status recognizing its component formations on the basis
of foraminiferal faunas (biozones). Scott (1991) reduced the Ocala Group to formational status
in accordance with the North American Stratigraphic Code (North American Commission on
Stratigraphic Nomenclature, 1983).
 The Ocala Limestone consists of nearly pure limestones and occasional dolostones. It
can be subdivided into lower and upper facies on the basis of lithology. The lower member is
composed of a white to cream-colored, fine to medium grained, poorly to moderately indurated,
very fossiliferous limestone (grainstone and packstone). The lower facies may not be present
throughout the areal extent of the Ocala Limestone and may be partially to completely
dolomitized in some regions (Miller, 1986). The upper facies is a white, poorly to well
indurated, poorly sorted, very fossiliferous limestone (grainstone, packstone and wackestone).
Silicified limestone (chert) is common in the upper facies. Fossils present in the Ocala
Limestone include abundant large and smaller foraminifers, echinoids, bryozoans and mollusks.
The large foraminifera Lepidocyclina sp. is abundant in the upper facies and extremely limited in
the lower facies. The presence of these large foraminifers in the upper facies is quite distinctive.
 The Ocala Limestone is at or near the surface within the Ocala Karst District in the west-
central to northwestern peninsula and within the Dougherty Plain District in the north-central
panhandle (Scott, in preparation). In these areas, the Ocala Limestone exhibits extensive
karstification. These karst features often have tens of feet (meters) of relief, dramatically
influencing the topography of the Ocala Karst District and the Dougherty Plain District (Scott, in
preparation). Numerous disappearing streams and springs occur within these areas.
 The permeable, highly transmissive carbonates of the Ocala Limestone form an important
part of the FAS. It is one of the most permeable rock units in the FAS (Miller, 1986).

 Tre Residuum on Eocene sediments The post-Eocene residuum lying on Eocene
sediments in the panhandle consists of reddish brown, sandy clays and clayey sands with
inclusions of weathered Eocene limestones. Some of the inclusions are silicified carbonates.

 Oligocene Series
 Lower Oligocene Rupelian Stage

 Previous geologic maps of Florida presented the Lower Oligocene sediments exposed at
the surface or in the shallow subsurface in a variety of ways. Cooke (1945) mapped, in
ascending order, the Marianna Limestone, Byram Formation, Suwannee Limestone and the Flint
River Formation. Vernon and Puri (1964) identified the Marianna Limestone, "Byram"
Formation, Duncan Church beds and the Suwannee Limestone. Brooks (1982) recognized the
Marianna Limestone, Suwannee Limestone and the Duncan Church facies of the Suwannee
Limestone. The variations in the stratigraphic units are indicative of the confusion over the
lithologic recognition and subdivision of the Lower Oligocene sediments. The confusion is at
least partially due to the use of biostratigraphic data to subdivide the lithostratigraphic units.