P&R Geological Consultants Pty Ltd., Scarborough, WA, Australia
The rift basins of East Africa are currently the site of renewed petroleum exploration efforts. This interest is based primarily on the proximity and geological analogy to large oil and gas fields in Sudan and Yemen, and has recently been renewed by the discoveries in Uganda. This region has a complex history of rifting: Karroo rifts of Permian - Jurassic age trend mainly NNE through Kenya, Ethiopia and Somalia; Upper Jurassic-Cretaceous rifts trend NW/SE through Sudan/Kenya and Yemen/Somalia; and Tertiary rifts, with sub-meridional trends onshore and NNW and NE trends in the Afar, Gulf of Aden and Red Sea. The younger rift trends cut across the older rift and sag basins, creating a locally complex basin framework.
Reconstructing the paleogeography of the East Africa basins requires an almost continent-scale regional approach. The integration of data from Ethiopia, Somalia, Kenya, Tanzania, Madagascar and Yemen has provided new insights into the paleo-geography of the Horn of Africa basins. Eight palaeogeographic maps from the Upper Permian to Lower Tertiary show the influence of Precambrian structure on Phanerozoic basin development and the impact of the younger rift events on the pre-existing basin framework and hydrocarbon potential.