Development of linear dunes in the southwestern Kalahari, Southern Africa

Linear dunes in the southwestern Kalahari have a characteristic morphology and set of patterns which are similar to those in the Simpson–Strzelecki and Great Sandy Deserts in Australia. The dunes are today largely fixed by vegetation, but were probably active in a period of higher wind velocities and possibly lower rainfall some 19–16,000 y.b.p. During this and probably other periods of dune formation, dunes evolved from sediment sources in lunettes and river valleys within the sand sea itself as well as by the mobilisation of stabilised sand sheets and older dunes.