Namib Sand Sea

The Namib Sand Sea (the Sossus Sand Formation) is a major physiographic feature of the Namib Desert, covering a 50–160 km wide region of the coast between Lüderitz and Walvis Bay and covering an area of ~34,000 km2 (Stone, 2013). It is bordered by the southern Atlantic Ocean to the west and by the Great Escarpment of southern Africa to east. New age control from cosmogenic dating indicates that the sand sea is more than a million years old (Vermeesch et al., 2010; Stone, 2013). The sand sea overlies a Neogene age fossil desert (the Tsondab Sandstone Formation). The sandy desert is dominated by large linear dunes and has areas of star-shaped dunes on its eastern margin and a belt of simple and compound transverse and barchanoid dunes along the coast (Livingstone, 2013). Linear and star dunes attain impressive heights, in excess of 150 m and 300 m, respectively. The Orange River is the predominant ultimate source of sand for the Namib Desert dunes. After long-distance fluvial transport, sand from the Orange River is washed by ocean waves and dragged northwards by vigorous longshore currents and under the incessant action of southerly winds, sand is blown inland and carried farther north to accumulate in the Namib erg, a peculiar wind-dominated sediment sink with the sand deposited hundreds of kilometers away from the mouth of the Orange River. (Garzanti et al., 2012).