The final period in Namibia's geological history leading to its present-day physical form is largely a continuation of processes that stemmed from the break-up of Gondwana as Africa and South America split. The final shaping of the landscapes of Namibia began with rivers carrying eroded material down to the South Atlantic Ocean that formed when the two continents separated. The coastal plain thus expanded as elevated inland areas were eroded and lost ground, progressively withdrawing eastwards. That process continues today at a slow, imperceptible pace.

The expanding coastal plain holds many geological remnants of times long past, such as inselbergs, faults and dykes. The composition of its surface is however largely a product of the weather and ocean currents present along the Namibian coast. These maintain its aridity, drive sand across its surface and polish its rocks. The Orange River, in combination with the Benguela Current, has also had a major impact on the coast, supplying the sand that accumulates as coastal dunes, as well as the diamonds that have added so much to Namibia’s economy. The quantity of sand and diamonds deposited onshore would have been much reduced if it were not for the wide continental shelf on which they could settle before being carried northwards.