Eastern African rift system


EASTERN AFRICAN RIFT SYSTEM (RU: Восточно-Африканская рифтовая система) is the system of the large tectonic faults (of the dip-slip tectonic faults) and grabens (rifts), which are well developed on the background of the recent uplifts of the Eastern Africa (see the Map).

The system extends along the meridional direction from the northern periphery of the Red Sea to the lower reaches of the Zambezi river. The system also includes the Red Sea graben with the branchings (the Gulf of Suez, and the Gulf of Aqaba), and the Gulf of Aden graben, which are joined within the region of the Afar depression. The system continues to the north through the Dead Sea to the foothills of the Taurus mountains. On the territory of Africa, this system comprises the two branches (western and eastern rifts), which are expressed within the relief as the deep and wide (40-50 kilometres) valleys with the precipitous slopes and depressions on the bottom, which are occupied by the lakes (Tanganyika, Malawi, and others). The eastern rift is connected through the Ethiopian rift with the Afar depression, and at the south, within the Malawi country, is connected with the western rift. There are confined to the longitudinal and transverse tectonic faults the volcanoes with the height of more than 5000 metres (Kenya, Kilimanjaro, Elgon, and others). The seismicity, which is inherent to the Eastern African rift system, testifies about the recent movements along the tectonic faults. There is also characteristic for the rift grabens the thinning of the continental crust, which is proceeding within the Red Sea and Gulf of Aden to the rupture of this crust, and to the partial replacement by the crust of the oceanic type. The forming of the Eastern African rift system has started during the Oligocene, and continues during the modern epoch, while proceeding within the situation of the explicit extension and separation of the continental crust, with the distancing of the Arabian and Somalian blocks from the African block proper.