The East African Rift opens
Africa starts tearing itself in two, and the valley it creates will later shape human evolution.
- When
- —
- Duration
- 8 million years
- Known to
- ± 2 million years
- Era
- Oligocene, Cenozoic
Doming and weakening above the Afar plume initiates continental extension from about 31 million years ago, first in the Gulf of Aden and Ethiopia and later propagating south. The rift creates a triple junction at Afar, uplifted shoulders, and a chain of deep basins that fill with lakes. Its indirect consequences are enormous: the rift shoulders block moisture from the Atlantic and dry East Africa, converting forest to mosaic woodland and savanna, and the rift's subsiding basins bury and preserve the sediments in which almost the entire hominin fossil record is found.