Wednesday, March 12, 2008

Continental breakup sea floor

An integrated approach to continental breakup: insights from central Ethiopia

San Diego State University Department of Geological Sciences Seminars Webinar Series

Dr. Tyrone Rooney San Diego State University Department of Geological Sciences

The East African Rift system is the archetypal example of continental rupture and has global significance in understanding extensional plate tectonic processes. We concentrate on the central Main Ethiopian Rift, which lies between the thicker continental crust in Southern Ethiopia and the thin predominately basaltic crust of the Afar Depression. We utilize Quaternary basaltic lavas erupted in tectono-magmatic fault belts to probe the source of rift magmatism and establish a connection between deeper mantle processes ( e.g. mantle plumes) and continental rifting. This study has also focussed on the relationship between magmatic intrusion in the continental lithosphere and extension. These geochemical results are combined with geophysical studies to produce an integrated geodynamic model for the progression of continental rifting along the Main Ethiopian Rift and call into question the concept of a simple transition between continental rifts and sea floor spreading centers.