Pleistocene Carbonate Seif Dunes and their Role in the Development of Complex Past and Present Coastlines of the U.A.E.

Abstract

Isolated outcrops of Pleistocene carbonate aeolianites and their cappings of shallow water Pleistocene marine limestones are described largely from Al Dabb'iya on the eastern end of the Great Pearl Bank, Abu Dhabi. Their sedimentological characteristics and depositional settings are discussed in relation to mainland Pleistocene aeolianite trends observed from satellite images. A comparison of the internal dune cross-bedding with dune morphologies suggests changing wind regimes that probably resulted from meteorological changes induced by the onset of a Pleistocene glacial period. The complex palaeo-geomorphology imposed by the dunes strongly influenced later Pleistocene coastal marine sedimentation that was concentrated in a series of shallow embayments separated by low-relief seif dunes forming peninsulas. Similar marine settings extended into the Holocene along parts of the United Arab Emirates coastline and still persist locally.