Alkaline Rocks and Carbonatites of the World

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Ayelu-Aabida (Ayyalu-Abida)

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Occurrence number: 
054-00-035
Country: 
Ethiopia
Region: 
Main Ethiopian Rift
Location: 
Longitude: 40.8, Latitude: 10.07

This is a large (45 km east-west) twin volcano the older and higher Ayelu centre lying west of Aabida. Ayelu is built of thick rhyolitic flows with the eastern flank covered by ignimbrites that were emitted from Aabida. Aabida is a strato volcano with a 5x4 km summit caldera within which is a trachytic dome. Ignimbrite, emanation of which led to formation of the caldera, covers a wide area and extends for up to 40 km from the summit. The ignimbrite is of a greenish colour, pantelleritic in composition and has surface 'blisters' similar to those described from Fantale (No. 36). Rock analyses and petrographic descriptions of Ayelu rocks will be found in Hieke (1950 and 1953).

Age: 
Aabida is of recent age with many fumaroles within the caldera and around the volcano.
References: 
HIEKE, M.O. 1950. I basalti dell’Africa Orientale. Memorie degli Istituti di Geologia e Mineralogia dell’Universita di Padova, 17: 1-42.HIEKE, M.O. 1953. Le vulcaniti acide dell’Africa Orientale. Memorie degli Istituti di Geologia e Mineralogia dell’Universita di Padova, 18: 1-45.VARET, J. 1978. Geology of Central and Southern Afar (Ethiopia and Djibouti Republic). Editions du Centre National de la Recherche Scientifique, Paris. (Explanation accompanying Geological map of central and southern Afar. 1:500,000).
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