Active rifting, magmatism and volcanism in the Afar Depression, Ethiopia

The Afar Depression forms a topographic low in north-eastern Ethiopia at the triple junction of the Red Sea, Gulf of Aden and Main Ethiopian Rifts at the northern end of the East African Rift system. This setting is one of few locations where active continental breakup and the transition to oceanic crust can be observed on land and serves as a unique natural laboratory to understand the processes involved (Makris and Ginzburg. 1987). The margins of the Afar Depression are marked by the Ethiopian plateau to the west, Somali plateau to the southeast and Danakil Highlands to the northeast. Since the emplacement of the Ethiopian Trap Basalts ~ 31-29 Ma, the Arabian plate has been moving away from the Nubian plate to form the Red Sea (Ebinger et al., 1993; Hofmann et al., 1997; Wolfenden et al., 2005). The inland continuation of the Red Sea extension is displayed in en-echelon ~ 60 km-long discrete magmatic rift segments which are foci for volcanic and tectonic activity: Erta’Ale, Tat’Ale, Alayta and Dabbahu-Manda Hararo (Acocella et al., 2008; Ebinger and Casey, 2001; Hayward and Ebinger, 1996). The Dabbahu-Manda Hararo magmatic segment is the southernmost segment to display the north-west – south-east orientation of the Red Sea Rift in Afar and therefore marks the propagating tip of the Red Sea Rift