Eastern Rift structural geology - tectonics, volcanology and geothermal

Abstract

Eastern rift is a branch of the larger East African Rift (EARS), an extensive continental rift on the Earth’s surface that extends from Gulf of Eden/Red Sea in SW Asia and propagates southward through East Africa to Mozambique near Beira. As the EARS propagates southwards from Afar triangle/triple junction, it separates into two branches namely Eastern and Western Branches. The Eastern branch includes the Ethiopian and Kenya rifts that are centered on Ethiopian and Kenyan domal hotspots respectively. Rifting tectonic episode started 30Ma in the Afar region. Magmatic and volcanic activities associated with domal uplift started during Miocene. Volcanism preceded the major rift faulting events and the mechanism of rifting process has been modeled to be as a result of elevated heat flow from the upper mantle that caused a pair of thermal bulge in the central Kenya and the Afar region of north central Ethiopia. The volcanic centres within the Eastern rift have elevated heat flow and fracture networks that has made it possible for existence of low to high geothermal systems.