Preliminary Biostratigraphy and Molluscan Fauna of the Goose Creek Limestone of Eastern South Carolina

Abstract

Despite 150 years of study, the stratigraphic relationship among Pliocene beds in South Carolina has not been clearly demonstrated. The Goose Creek Limestone and the closely related Raysor Marl have been particularly perplexing. Previously reported Goose Creek faunules have been too meager for effective comparison. Discoveries at the Martin Marietta Berkeley County Quarry and the Mason Dixon pit tripled the total number of documented species from the Goose Creek Limestone and provided a basis for correlating various literature records and Charleston Museum collections. The Goose Creek Limestone is divisible biostratigraphically into informal lower and upper units. These fauna! units appear coincident with a lithic division, separated by an unconformity. The Raysor Marl unconformably overlies the lower Goose Creek Limestone, reversing the inferred stratigraphic sequence prevailing in current literature. Raysor Marl and upper Goose Creek Limestone faunules share numerous index taxa and appear to be laterally equivalent, coeval lithofacies. Both units are distinct from, and older than, the Duplin Formation at its Natural Well stratotype. The Bear Bluff Formation, at its stratotype locality, is lithically and faunally congruent with the upper Goose Creek Limestone.