Implications of Clay-Provenance Studies in Two Georgia Estuaries

Abstract

ABSTRACT The amount of kaolinite and illite in bottom muds of Altamaha River and Sound, a partially-mixed estuary, does not vary appreciably downstream, indicating that the bulk of the clays is river-supplied. In contrast, much of the bottom mud of Sapelo Sound, a tidal-water body with minor freshwater discharge, seems to be derived from erosion of coastal outcrops. Our results suggest that the clay flux from ocean sources is minimal in either case, and tends to have been overestimated by previous workers. On the other hand, the clay flux from shore erosion tends to have been underestimated in sediment-budget studies of Georgia estuaries.