Abstract

The NW Red Sea-Gulf of Suez rift system was initiated during Late Oligocene time and underwent extension in a N65°E direction, almost orthogonal to pre-existing WNW-trending Pan African shear-zone fabrics in the crystalline basement of the Sinai-African plate. Earliest syn-rift sediments are Upper Oligocene continental clastic deposits with minor syn-rift basalts. Early Miocene sedimentation was dominated by shallow marine clastic deposits, which developed variable stratigraphic architectures as a response to the interaction of extensional faulting, sea-level changes, sediment supply and dispersal. Analysis of fault geometries, fault kinematics and sedimentation patterns indicates that rift-normal extension predominated throughout the Late Oligocene-Early Mid-Miocene evolution of the rift. Reactivation of the Precambrian basement fabrics was the main factor controlling the fault architecture, fault linkage and evolution of the NW Red Sea-Gulf of Suez rift. Individual faults were initially strongly segmented and offset across ‘soft-linked’ relay structures. With increased extension these faults became linked by breaking down relay structures with the development of local ‘hard-linked’ transfer faults, thus giving rise to the rhomboidal fault pattern of the rift system. In Mid-Miocene time, the Levant-Gulf of Aqaba transform boundary was established, linking the Red Sea rift plate boundary to the convergent Bitlis-Zagros plate boundary. This resulted in a dramatic decrease in extension rates within the Gulf of Suez whereas the northern Red Sea continued to extend, with significant syn-rift sediments deposited in Late Miocene-Pliocene time in offshore fault-bounded basins.