East African Rift - Wikipedia OverviewExtentCompeting theories on geologic evolutionGeologic evolutionPetrologyVolcanism and seismicityThe East African Rift is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago. In the past it was considered to be part of a larger Great Rift Valley that extended north to Asia Minor. The rift, a narrow zone, is a developing divergent tectonic plate boundary where the African Plate is in the process of splitting into two tectonic plates, called the Somali Plate and the Nubian Plate, at a rate of 6–7 mm..See more on enpedia · Text under CC-BY-SA license East Africa's Great Rift Valley: A Complex Rift System geology›Plate TectonicsMost rifts in other parts of the world have progressed to the point that they are now either under water or have been filled in with sediments and are thus hard to study directly. The East African Rift System however, is an excellent field laboratory to study a modern, actively developing rift system.