Paleoecology of Crepidula (Mollusca: Gastropoda) Beds, James City Formation (Pleistocene), North Carolina

Abstract

Masses of life-oriented valves of the marine gastropod Crepidula fornicata (Linne, 1758) form lenses in the James City Formation (Pleistocene) of North Carolina. The units are exposed along the banks of the Neuse River estuary in Craven County, near Johnson Point. Three other types of lithologic units, which occur in the bluffs at Johnson Point and differ (to various degrees) with respect to taxonomic composition and sedimentology, are dense clay layers, shell-hash layers, and dispersed shell beds. The primary distinguishing characteristics of the Crepidula beds include high shell/matrix ratio, high abundance of C. Jomicata, and high relative proportion of epifaunal suspension feeders. The Crepidula beds may be classified as "minor simple shell beds" (terminology of Kidwell, 1982) produced through the biologic activity of epifaunal organisms.