Widely dispersed Quaternary tephra in Africa

Several prominent widespread Pleistocene tephra layers have been recognised and correlated across northern Kenya, Ethiopia and Uganda. A single unit has been correlated between Lake Turkana and the Gulf of Aden. Each of these tephra units represents the products of an eruption of at least 4 km3 of magma. The number of active volcanoes within the African rift valleys suggests that there should be an order of magnitude more widespread tephra layers than have yet been correlated. Further study of the short cores recovered from East African lakes and mire deposits, integrated with ongoing research on the young or active caldera volcanoes of the East African Rift, should yield many more marker tuffs from the Holocene and late Pleistocene. The prospects for developing a high-resolution record of rift volcanism for the past 40,000 years are very good.