Source of Tidal Creek Sand on a Tide-Dominated Barrier Island, St. Catherines Island, Georgia: Fourier Shape Analysis

Abstract

 

Seaside Creek, as well as other tidal creeks of St. Catherines Island (a barrier island in the Georgia Embayment) is a sand bottomed channel incising fine grained marsh sediment. The coarse channel bottom sediment can be derived from either or both of two sources. Headwardly, the creeks erode into the Pleistocene core of the island. At the inlets, sand is being contributed by littoral drift. Fourier analysis of the shape of quartz fine sand (180-250 microns) shows that the major source of sand in Seaside Creek (and, presumably, other creeks on St. Catherines Island) is the island core with contributions of littoral drift sediment only at the tidal inlet throat.