Geology and Soils

Abstract

On the basis of its geological features, WEllington (1946) divided the Zambezi River Catchment (Fig. 1) into three regions:

• 1. Plateau Tract dominated by Kalahari Sediments (Barotse Plain and northern edge of the Ngami Depression). In its southeastern part between the Zambesi/Chobe confluence and the end of the Batoke Gorge (Fig.4), the Zambezi Valley is cut in basalts (basic lavas) part of the Batoka Basalt of the Stormberg Age (Upper Karroo). To the east the basalt outcrop is terminated by a north-easterly trending fault down-throwing basalt against the much softer Upper Karroo Sandstones. It is thought that the Victoria Falls might well have been initiated at this point (ANON., 1962).

• 2. Trough Tract, a structural feature in which Karroo sediments have been deposited between rocks of the Basement Complex (Fig. 4). It includes the Gwenbe Valley and terminates eastwards at the Cabora Bassa rapids.

• 3. Lowland Tract, composed of the Manica Platform (Cabora Bassa to Luputa Gorge) and of the Mozambique Plain (marine deposits, Cretaceous to Recent).