TWO ARCHAEOLOGICAL AND PALEONTOLOGICAL LOCALITIES ON THE ATLANTIC SOUTHEASTERN U.S. CONTINENTAL SHELF, GRAY'S REEF NATIONAL MARINE SANCTUARY AND J-REEF (GEORGIA)

Systematic survey and limited excavation at Gray's Reef National Marine Sanctuary (Georgia), 32 km offshore Georgia, and nearby J-Reef, in the Atlantic Ocean, has identified two localities containing vertebrate fossil remains and two artifacts - one an organic artifact - a bone/antler tool and the other lithic - a projectile point typologically assigned to the early Middle Archaic Period. Post-glacial sea level over-stepped the 17-20 m depths, at these locations, during the Archaic Period, ca. 8000 BP. Before that overstep, as far back as 40,000 BP, the area around Gray's Reef and J-Reef was a subaerial coastal plain. During the Holocene (post-12, 000 BP) relative sea level (RSL) continued its rise from its full glacial regression of over-100 meters below present-day levels (4). Sea level regression began well before the Late Glacial Maximum (LGM) ca. 21,000 BP or Marine Oxygen Isotope Stage - 2 (MIS - 2). At Gray's Reef, the direct dating of sediments and other materials such as shell, wood and bone (Table 1), indicates a subaerial exposure of a now-drowned coastal plain, dating from several millennia before the LGM (ca. 40,000 BP) to the early Holocene transgression, 8-9,000 BP. Geoarchaeological studies at Gray's Reef have, since 1996, confirmed an allogenic nature for the fossils assemblage and artifacts' provenance.