Drainage evolution in south-central Africa since the breakup of Gondwana

Flood analysis of the Limpopo River basin through past evolution reconstruction and a geomorphological approach

“…The east still represents the dominant flowing direction of the fluvial system in southern Africa today, with Mozambique, located downstream, receiving nine international rivers in its territory. Figure 5 is derived from the drainage reconstructions of Moore (1999), who based some of his deductions on early intuitions of Du Toit (1933) later confirmed by De Wit (1999), Moore and Larkin (2001) and Goudie (2005). It shows clearly that the palaeo-Limpopo River during the early Cretaceous period was by far the largest river of southern Africa, as it also included the southeastwards flowing Cuando, Okavango and upper Zambezi rivers as its main tributaries.…”

“…It shows clearly that the palaeo-Limpopo River during the early Cretaceous period was by far the largest river of southern Africa, as it also included the southeastwards flowing Cuando, Okavango and upper Zambezi rivers as its main tributaries. The latter, which was most probably linked to the Limpopo through the Shashe River (Moore and Larkin, 2001), received waters from the Kafue and Luangwa rivers originally flowing in a southwesterly direction (Moore and Blenkinsop, 2002). Moore and Blenkinsop (2002) and Moore et al (2007) indicate that the palaeo-Limpopo River entered the coastal plain of Mozambique by exploiting the corridor traced by the Botswana dyke swarm oriented along a east-northwest direction (see Fig.…”

“…6) that arose due to plate tectonics in southern Africa. These axes of uplifting, which define the divides of important river watersheds today, have much influenced the drainage evolution in the region by determining successive river cuts and river captures (Moore and Larkin, 2001). According to Moore (1999) and Moore et al (2009b), they appeared in the following chronological order:…”

Geomorphic Landforms and Tectonism Along the Eastern Margin of the Okavango Rift Zone, North Western Botswana as Deduced from Geophysical Data in the Area

“…Initiation of current rifting processes in the ORZ are unknown; however, paleoenvironmental reconstruction from sediments collected in Lake Ngami suggests that feeder rivers promoted extensive flow beyond the Thamalakane and Kunyere faults circa and beyond into the Makgadikgadi pans (Shaw, 1995). Between 120 Ka and ~ 40 Ka, neotectonic activity resulted in uplift along the Zimbabwe-Kalahari axis and displacement along the northeast-southwest trending faults resulting in the impoundment of the protoOkavango, Kwando, and the upper Zambezi rivers and the development of the protoMakgadikgadi, Ngami, and Mababe sub-basins (Cooke 1984;Thomas and Shaw, 1991;Moore and Larkin, 2001) suggesting that rifting may have been initiated about 40 Ka.…”

The Okavango; a river supporting its people, environment and economic development

“…Geological evidence suggests that the Okavango River, along with the parallel Kwando and upper Zambezi Rivers flowed southeastward in late Pliocene-early Pleistocene time into the Limpopo catchment (Moore and Larkin, 2001). The lower Zambezi River forming the Zambezi system, which subsequently captured the Kwando along the Okavango fault lines, has since captured the upper Zambezi.…”