Abstract: Reevaluating Florida Basement

Russell A. Wicker, Douglas L. Smith

A generalized representation of the basement and overlying sedimentary rocks of peninsular Florida has been developed utilizing available gravity-anomaly values, deep test-well data, and a variation of the Talwani two-dimensional gravity-modeling technique. Subsurface density and depth values along 10 profiles were adapted to an iterative calculating process to generate gravity-anomaly profiles conforming to those observed. Modeled cross sections along these profiles then were used to interpolate basement and sedimentary configurations for the entire peninsula. The final models display the low-density (1.95 to 2.15 g/cc) near-surface rocks of Late Cretaceous to Holocene ages extending to depths ranging from approximately 0.8 to 2.6 km. Depths of the underlying Lower Creta eous rocks (density of 2.30 to 2.55 g/cc) extend to approximately 1.4 km in north Florida and to more than 4.7 km in south Florida. An abrupt north-to-south increase in average basement rock density from 2.73 to 3.00 g/cc is evident along a general east-west trending zone passing through the central part of the peninsula. This supports the concept of a north-to-south transition from continental to oceanic type rocks underlying the thick sedimentary sequences of the central Florida peninsula.

AAPG Search and Discovery Article #90965©1978 GCAGS and GC Section SEPM, New Orleans, Louisiana