Extensional tectonics and sedimentation, eastern Gulf of Suez, Egypt

Abstract

The eastern margin of the Gulf of Suez displays spectacular interrelationships between rift-border fault systems and sedimentation patterns. The structural and sedimentological evolution of a 100 km long segment of the well-exposed eastern margin of the Gulf of Suez rift has been studied by detailed field map**, structural and sedimentological analysis together with analysis of Landsat TM and SPOT data. The eastern margin of the Gulf of Suez between Hammam Faraun in the north and Gebel Araba in the south is formed by a series of north-west trending, south-west dip** rift-border faults that are segmented and offset in an en-echelon pattern together with a second set of segmented, north- west trending, south-west dip**, major intra-rift faults that form the ‘coastal fault system’. In cross-section the faults are typically south-west dip**, planar domino — to gently curving listric in shape. The pre-rift stratigraphy includes crystalline Pan-African basement rocks (largely metavolcanics, migmatites and granites) and a pre-rift sedimentary succession of elastics and carbonates that ranges in age from the Cambrian through to the Eocene. Syn-rift elastics and carbonates range from the Oligocene through to the Recent and typically show depositional patterns which relate to the geometries of the extensional fault systems. Shallow marine Miocene syn-rift elastics were deposited in fault-bounded sub- basins at the rift margin and fanglomerate bodies with well-developed progradational wedge geometries formed in the hangingwalls of major rift-border faults. Continued movement along the major fault systems has deformed the pre-rift and syn-rift sequences leading to the present-day structural configurations.