SCOUR NUCLEI AS TARGETS FOR MARINE GEOARCHAEOLOGY IN THE GEORGIA BIGHT: EVIDENCE FROM ENVIRONMENTAL DNA AND PALYNOLOGY

On the eastern coast of North America, post-LGM marine transgression and sedimentation has covered prehistoric terrestrial ecosystems and artifacts of any coastal human activity, but evidence of both may be preserved in sediments just below the modern sand sheet on the wide, shallow continental shelf of the Georgia Bight. Indeed, offshore artificial reefs have yielded terrestrial vertebrate bones and lithic artifacts. However, the layer of Holocene sand comprising the sea floor sediment surface of the continental shelf obscures deposits older than approximately six kya. Study of terrestrial paleoecology or archeology prior to the establishment of the modern shoreline therefore requires not just marine archeology, but removal of the modern sediment.

We propose scour nuclei – erosional features caused by current flow over any sea floor obstruction – as target sites to study the sediment beneath Holocene sand on the Georgia Bight. Substantial scour nuclei have formed adjacent to several vessels sunk off the coast by the Georgia Department of Natual Resources to form artificial reefs. In some cases, scour reveals sediment from Marine Isotope Stage 3 (32-46 kya); thus, they are suitable targets for prehistoric palaeoecological and archeological exploration. Here, we present results from the ROV assisted exploration of three scour nuclei sites from two artificial reefs in the Georgia Bight (L; KC_B and KC Motherlode). Sediment samples were collected, and pollen and environmental DNA were analyzed for evidence of pre-Holocene terrestrial ecology.