SOFIA - MGS-Winston-v2 1993, The Paleogene of Florida, Volume 2, A Regional Analysis of the Oligocene-Eocene Section of the Peninsula Using Vertical Lithologic Stacks

The Paleogene of Florida, Volume 2, A Regional Analysis of the Oligocene-Eocene Section of the Peninsula Using Vertical Lithologic Stacks

George O. Winston

ABSTRACT

This report is based on my descriptions of numerous sample sets from various stratigraphic investigations in Florida (Winston 1977, 1978, 1990, 1991, Puri & Winston 1974 and Winston & Puri 1975). In order to make paleogeographic interpretations of some 2500 feet of diverse carbonate lithologies without regional paleontologic or lithologic marker beds, I have organized these rocks into VERTICAL stacks based on similar lithologies, herein designated "Suites". These Suites cross stratigraphic boundaries.

All of the Suites of the Black Point Format include Oligocene and Eocene age rock between the base of the phosphatic Miocene Hawthorn and the top of the Paleocene Cedar Keys-Rebecca Shoal dolomite complex (Winston 1977, 1978, 1989 & 1991). The MADco Suite, which belongs to the Perdido Bay Format of the Panhandle (Winston 1993), extends into the geographic Peninsula province. The MADco Suite includes beds of Paleocene age in addition to Oligocene and Eocene rocks.

The MADco Suite is a light-colored skeletal, open marine wackestone which contains glauconite, chert and some dolomite. The PINco and ORco Suites are mostly tan and brown dolomite, with the PINco being differentiated by the presence of varying amounts of anhydrite.

The CHAco, DAco and LAFco Suites are characterized by a predominance of light-colored, chalky skeletal limestone, and subsidiary brown dolomite. In the DAco Suite, dolomite is a relatively minor constituent, whereas in the CHAco Suite it is a major component. The LAFco is differentiated from these Suites by the presence of both glauconite and chert.

All of the Black Point Suites were deposited on a tableland created by the underlying Paleocene Rebecca Shoal barrier reef atoll and its lagoonal carbonate-evaporite facies, the Cedar Keys Formation. The dolomite PINco and ORco Suites of the central tableland are encircled on the north, east and south by the dominantly limestone LAFco, CHAco and DAco Suites.

In the southeastern Peninsula the absence of the Ocala Limestone can be explained by a change of facies of that unit into upper Avon Park lithology, without invoking a short-lived uplift to permit erosion of this unit. Drill cutting data from wells in Dade County strongly suggest continuous deposition from the Avon Park through the Suwannee.

Four zones of Helicostegina gyralis occur in the northern Peninsula; the type Oldsmar top in the PINco Suite is associated with Zone III (see Fig. 13).

(The entire report is available below)