Luangwa River ago, there was no way out and the Luangwa Rift filled with a Rift Valley Lake called the Madumabisa Lake, which rivalled Lake Malawi in size. The water of the lake overflowed in a river to the south-west, towards what is now the Kalahari, where it combined with the Okavango, Upper Zambezi, Cuando and Kafue rivers, emptying into the Limpopo River and flowing to the Indian Ocean. Several geological events combined to produce the current river systems. Faulting produced another graben just to the south of the Luangwa Rift, and running east-west: the Zambezi Rift Valley and the Chicoa Trough.
Zambezi Escarpment Zambezi Escarpment Zambezi Escarpment is a name used for the escarpments forming both sides of the rift valley or graben in which lie the middle Zambezi river and Lake Kariba. They are fault scarps, rising 500 to 600 m higher than the lake or river, running from the Batoka Gorge roughly 800 km to the lower Zambezi, and facing each other about 50 to 100 km apart, closer in the west and opening up in the east. The northern Zambezi Escarpment in Zambia is steeper. It is somewhat broken north of Lake Kariba, but is particularly steep and well-formed from