The Accumulation of The Sand Sea

Sand seas are the largest aeolian sand bodies and contain considerable volumes of aeolian sand, together with local but significant amounts of interdune and extra-dune fluvial lacustrine and marine sediments (Lupe and Ahlbrandt 1979 ). Their accumulation probably requires long periods of geological time. Estimates of the time required for modem sand seas in the Sahara to accumulate range from 1.35 to 2 Ma, but up to 50 Ma may be required to reach full equilibrium with sand flow conditions ( Wilson 1971 ). On this time scale, tectonic effects and basin subsidence will become significant factors in sand sea accumulation, as evidenced by the 300 m of aeolian sand beneath the Murzuq Sand Sea in Libya ( Glennie 1970 ). In contrast to the considerable lengths of time for sand sea accumulation envisaged by Wilson and Glennie, Ahlbrandt et al. (1983 ) argue that the 924 m thickness of sand in the Nebraska Sand Hills was deposited during the period 6000–8000 BP.