Geologic History of Florida-Bahama Platform, Triassic Through Paleocene

George O. Winston

This study is based on top-to-bottom examination of samples from 146 wells from the Florida-Bahama platform. Following Triassic graben formation, three different structural configurations develop through time. In the Late Jurassic-Coahuilan, a northwestern and southeastern sedimentary province were separated by the Sarasota arch, located on the west Florida shelf. Modern basin configurations, which began to appear in the Comanchean, were modified by tectonics in Cuba in the early Gulfian. From the Late Jurassic through the Comanchean, the continental margin was occupied by a carbonate complex that restricted marine circulation in some areas. In the southeast, this barrier caused the deposition of lagoonal carbonates and anhydrites; in the north, clastics were deposited. Carbonate-evaporite deposition in the south ended at the close of the Comanchea and was followed by the deposition of chalk and chalky limestone in the Gulfian. During this epoch, the rapid subsidence of the Blake Plateau basin to bathal depths and the collapse of the Florida straits were associated with tectonic activity in northern Cuba. By the middle Gulfian, the Rebecca Shoal barrier reef had appeared on the upthrown northern side of the straits. This barrier reef expanded to encircle the Florida peninsula completely, at which time the Cedar Keys (Paleocene) lagoonal dolomite-anhydrite deposition was initiated.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.