Alkaline Rocks and Carbonatites of the World

Setup during HiTech AlkCarb: an online database of alkaline rock and carbonatite occurrences

Main Ethiopian Rift

Main Ethiopian Rift

The 'Main Ethiopian Rift' extends for some 600 km from the Afar Depression south-southwestwards to the Kenya border. Centred on the rift and the adjacent rift shoulders are numerous volcanoes that are mainly alkaline, many being composed predominantly of peralkaline silicic rocks. Descriptions of these centres follow (Nos 054-00-033-054-00-053). Much of the rift floor is covered by welded to unwelded ash-flow and pumice deposits of peralkaline rhyolitic composition which were probably erupted from fissures (Merla et al., 1979), although some may have emanated from the central volcanoes. There are few detailed descriptions of these deposits but information on the central part of the rift will be found in Di Paola (1973) and on the evolution of the northern part of the rift in Kazmin et al. (1980). A general account of the relationships between tectonics and volcanism is that of Mohr (1983) who has collected together chemical data (Mohr, 1962a). Some 77 K-Ar dates for volcanic rocks within the rift and for volcanoes of the rift shoulders will be found in Woldegabriel et al. (1990).

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Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith