T124 Coastal and Island Geoarchaeology

Monday, 16 October 2023
1:30 PM - 5:30 PM
330

NOVEL EXAMINATION OF SEA FLOOR SCOUR AND THE DISCOVERY OF AN EXTANT PALEO-LANDFORM, GEORGIA BIGHT, USA

Paper number: T124-5
Program: Technical Sessions
Time: 2:25 PM – 2:40 PM

Authors

Abstract

Sea floor scour, nucleated by large artificial reef structures such as vessel hulks, barges, train cars, military vehicles, etc., herein called "scour nuclei," has exposed a previously buried paleo-landform on the Continental Shelf. At artificial reef structures - a 30 m steel barges - a relic paleo-landform with in situ sapling-size tree stumps and fossil animal bone has been uncovered by scour adjacent to the reef structure. Turbulence produced by tidal and wind-generated currents in the Georgia Bight has produced scour pits termed by others as "moats." The modern palimpsest sand sheet has been removed to depths of over a meter. Further afield, a larger area, termed "a comet", of less deep scour extends roughly at the same scale as the nucleating feature. The so-called comet stretches over 30 meters from the barge on what is the "down-current" side of the structure. While tidal currents operate twice daily in the Georgia Bight, ebb currents are typically stronger than those associated with the flood tide. This difference produces the asymmetry seen in the distribution and size of scour features. At Reef SAV, we report, herein, the discovery of a Marine Isotope Stage 3 paleo-landform, dated to 40,800 to 49,670 YBP by AMS-radiocarbon means.

Geological Society of America Abstracts with Programs. Vol. 55, No. 6

doi: 10.1130/abs/2023AM-394418

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