Beaches and beach-related facies, Holocene barrier islands of Georgia

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Abstract
The mesotidal coast of Georgia encompasses diverse sedimentary features and depositional environments, most of which typify major facies of the entire Georgia Bight – a broad embayment on the southeastern U.S. shelf. Barrier island strandline environments especially include tidal inlets and shoals, the beach shoreface, foreshore, and backshore, and dunes and washover fans. Low energy beach segments may grade directly into small seaside tidal flats. Relict salt marsh deposits crop out on erosional beaches. All deposits are in dynamic equilibrium with fluctuating coastal conditions and a gradual rise in sea level. Most of these facies are important in interpreting ancient epeiric transgressive/regressive coastal sequences. Pronounced local variations in the overall sequence result from complex latero-vertical relationships between (1) the shoreface, foreshore, and shoals, and (2) the shoals, low energy beaches, and beach-related tidal flats. Washover fans and relict deposits on erosional beaches cause perturbations within present day lateral relationships but are normal in transgressive facies tracts along such coasts. Close stratigraphic control of outcrops or cores would be necessary for detailed reconstructions of, or correlations among, ancient analogs.