Abstract
Radiocarbon dating of paleoliquefaction features near Bluffton in Beaufort County, South Carolina, indicates a likelihood of four prehistoric seismic events that occurred at 500 ±180, 1180 ±220, 2355 ±365, and 3355 ±485 yr B.P. Among these, the 500 ±180 and 2355 ±365 yr B.P. events appear to have originated near Bluffton, outside of the currently active Charleston seismic source zone. Association of these two events with a local source near Bluffton conflicts with the idea of periodic activation of a single seismic source near Charleston. The felt shocks of 1826, 1903, and 1912, reported from ∼20 km south of the paleoliquefaction sites, and a small earthquake on January 1989 located near Bluffton indicate that this area has been moderately active in historic times. Releveling data have identified an ∼30-km-long zone of uplift in the area. Stratigraphic data indicate the presence of an east-trending buried fault in the vicinity. These observations imply the presence of an additional seismic source zone in the South Carolina coastal plain, near Bluffton.