East African Rift

The East African Rift is part of the larger Great Rift Valley. It is a continental rift zone that appears to be a developing divergent tectonic plate boundary. The rift is a narrow zone in which the African Plate is in the process of splitting into two new plates called the Nubian and Somalian subplates or protoplates. It runs from the Afar Triple Junction in the Afar Depression southward through eastern Africa. It is believed to run offshore of the coast of Mozambique along the Kerimba and Lacerda rifts or grabens, [ http://www.nature.com/nature/journal/v321/n6070/abs/321599a0.html Seaward extension of the East African Rift, Letters to Nature 321, 599 - 603 (05 June 1986) Nature] terminating in the Andrew Bain Fracture Zone complex, where it is believed to have its junction with the Southwest Indian Ridge. [ http://geology.geoscienceworld.org/cgi/content/abstract/30/4/339 "Location of the Nubia-Somalia boundary along the Southwest Indian Ridge", "Geology", Apr.2002]

The East African Rift is unusual in that most of the world's active rifts are found in oceanic crust, and mostly beneath the seas. Besides the much smaller Baikal Rift Zone in eastern Russia and the remote, ice sheet-covered West Antarctic Rift, it is the only other example of actively rifting continental crust on Earth.

The East African Rift consists of two main branches called the Eastern Rift Valley and the Western Rift Valley. These result from the actions of numerous normal (dip-slip) faults which are typical of all tectonic rift zones.

Volcanic activity

The East African Rift zone includes a number of active as well as dormant volcanoes. These include Mount Kilimanjaro, Mount Kenya, Mount Karisimbi, Mount Nyiragongo, Mount Meru and Mount Elgon as well as the Crater Highlands in Tanzania. The Ol Doinyo Lengai volcano remains active, and is currently the only natrocarbonatite volcano in the world.

References