ABSTRACT

Comparative size analyses of adjacent foreshore, berm, and dune sediments were conducted along a coastal barrier chain of the Middle Atlantic Bight between Cape Henry, Virginia and Cape Hatteras, North Carolina. The three genetic populations are comprised of characteristic sub-populations, and exhibit statistically significant textural differences. Their textural attributes are interpreted in terms of a proposed conceptual model for the transverse transport system of barrier sediments.

During fair weather conditions, barrier sediments are subjected to sequential environmental processes, resulting in the acquisition of distinctive and cumulative textural response characteristics. The foreshore population is generated largely through aqueous processes associated with the normal swash-backwash regime, with only minor response to aeolian processes; whereas, the berm population is generated by high water swash-backwash regimes, and is substantially modified by subsequent aeolian processes. The dune population is generated entirely by the aeolian regime, and represents a clastic filtrate derived from adjacent berm and aeolian flat deposits. The distinctive response characteristics of the three genetic populations tend to be obliterated by inter-population feedback, and th ough storm homogenization by washover fans. Characteristic textural responses of the genetic populations appear to be determined both by the types of operative processes within an environment, and by their relative effectiveness.