Читать книгу Bats of Southern and Central Africa - Ara Monadjem - Страница 34

Major zones of uplift and faulting across southern Africa created the Luangwa, Gwembe and Kamalondo rift valleys. Precursors of these graben first formed during Karoo times (350–180 Ma). This tectonic activity is associated with the rifting that continues across Africa today in the East African Rift System, which started to propagate into southern Africa about 20 Ma. The East African Rift is a narrow zone in which the African Plate is in the process of splitting into two new tectonic plates. The dramatic scarps and graben that characterise the East African Rift System are very young when considered against the deep antiquity of the continent’s geological history; nevertheless, they are of key importance in controlling biotic evolution (see Geomorphology below). The chain of rift valleys propagates south across East Africa from Afar, Ethiopia, diverging into two discrete forks across southern Africa. One is expressed southward, through Malawi into the Urema Trough of Mozambique; the second extends southwest into the Okavango graben in northeastern Botswana from Katanga (DRC) and Zambia.