LAUSR

Abstract The structural and stratigraphic evolution of rift basins has been documented globally from modern systems, outcrop and subsurface datasets. Extensive fragmentation and break-up of Gondwana during the Cretaceous created a complex suite of rift basins in the Northern Africa. The Beni Suef rift basin straddles the River Nile and is infilled by a thick Mesozoic–Tertiary succession. Cenomanian–Turonian deposition commenced with the sandstone-dominated Bahariya Formation. Depositional environments transitioned stratigraphically from fluvial-marine to shallow marine and finally to mixed clastic and non-clastic shelfal deposits of the Abu Roash Formation. Sedimentation styles were tectonically controlled showing transgressive-to-regressive depositional cycles developed over the Gondwana rift systems. Cycles were controlled by short-lived, small-scale tectonic oscillations of the platform, resulting in four depositional sequences. Deposition environments in the Cenomanian transitioned from shallow marine to deeper marine shelfal deposits and finally to a coastal environment. During Late Cenomanian–Early Turonian, rapid platform submergence resulted in a transgressive facies succession, topped by deltaic deposits. In the Middle–Upper Turonian, two sequences formed with an intervening short-lived period of lower relative sea level. Relative sea-level oscillations were partly in phase with the global sea-level changes, controlled by local tectonics induced by the fragmentation of Gondwana during the Late Cretaceous.