Early magmatism in the greater Red Sea Rift; timing and significance
Early magmatism in the greater Red Sea Rift; timing and significance (in Uniformitarianism and plate tectonics; a tribute to Kevin C.A. Burke and John F. Dewey--L'uniformitarisme et la tectonique des plaques; hommage a Kevin C.A. Burke et a John F. Dewey, A. M. Celal Sengor (editor) and Ali Polat (editor))
Canadian Journal of Earth Sciences = Revue Canadienne des Sciences de la Terre (November 2016) 53 (11): 1158-1176
Throughout the greater Red Sea rift system the initial late Cenozoic syn-rift strata and extensional faulting are closely associated with alkali basaltic volcanism. Older stratigraphic units are either pre-rift or deposited during pre-rupture mechanical weakening of the lithosphere. The East African superplume appeared in northeast Africa approximately 46 Ma but was not accompanied by any significant extensional faulting. Continental rifting began in the eastern and central Gulf of Aden at approximately 31-30 Ma coeval with the onset of continental flood volcanism in northern Ethiopia, Eritrea, and western Yemen. Volcanism appeared soon after at Derudeb in southern Sudan and at Harrats Hadan and As Sirat in Saudi Arabia. From approximately 26.5 to 25 Ma a new phase of volcanism began with the intrusion of a dike field reaching southeast of Afar into the Ogaden. At 24-23 Ma dikes were emplaced nearly simultaneously north of Afar and reached over 2000 km into northern Egypt. The dike event linked Afar to the smaller Cairo mini-plume and corresponds to initiation of lithospheric extension and rupture in the central and northern Red Sea and Gulf of Suez. By approximately 21 Ma the dike intrusions along the entire length of the Red Sea were completed. Each episodic enlargement of the greater Red Sea rift system was triggered and facilitated by breakthrough of mantle-derived plumes. However, the absence of any volumetrically significant rift-related volcanism during the main phase of Miocene central and northern Red Sea - Gulf of Suez rifting supports the interpretation that plate-boundary forces likely drove overall separation of Arabia from Africa.