Tectono-Stratigraphic Evolution of the Western Somali basin: Sediment Dynamics, Margin Instability and the Legacy of the East African Rift System

The evolution of the East African Margin changed drastically after the onset of East African Rift System (EARS). The uplift of the coastal basins and the formation of new rift structures in both onshore and offshore domains modified not only the rate of sediment delivery to the western Somali basin but also the sediment distribution pathways. Such changes have been recorded in the stratigraphy offshore Tanzania by a series of sediment depocenters bounded by basin-wide unconformities and laterally confined by main structural lineaments. In this contribution we reconstructed the post-Oligocene tectono-stratigraphic history of the Tanzanian margin by using a combination of large broadband multiclient seismic data and few boreholes, aiming to elucidate the role of the EARS in promoting sediment supply to the basin, in modifying the path of ocean bottom circulation and in triggering mass failure phenomena.