The Namib Desert in south western Africa, has a long history of evolution. In the Cretaceous the opening of the South Atlantic and the presence of a mantle plume led to the emplacement of various major intrusions and the eruption of great spreads of lava - the Etendeka lavas. The present landscape of the Namib shows the impression of these events. In addition, there is evidence that aridity has characterised the area for much of the last 140 million years, and that processes such as salt weathering have led to the planation of extensive areas. The Namib is dominated by the major intrusions, by wide plains, and by a Great Escarpment.