Tectonic Trends, Timing, and Mechanics of the Egyptian Edge of the Red Sea and Gulf of Suez: ABSTRACT

Two major areas of onshore preservation of both pre-and syn-Red Sea sediments occur at Gebel Zeit, near the mouth of the Gulf of Suez, and at Quseir, 200 km (125 mi) to the south. At Quseir, a belt of 600 m.y. greenstone basement has at least three stages of coaxial N30°W deformation curving northwestward into N60°W grain of the regional Hamrawein Synclinorium. In Late Eocene (?) to Early Miocene time, this northwest-trending structure was further downwarped by block faulting with associated local gravity fold tectonics. The Cenozoic synclinorium dies out southeastward into a synchronous or slightly older system of north-south trending fault blocks, many of which show early stage right-lateral strike-slip slickenslides. In the Mid-Miocene, the Red Sea coast suffered major downwarping along N25°W trends, whereas the interior synclinorium was further broken into generally northwest-trending, northeast-tilted irregular fault blocks reactivating many older fault trends. By contrast, the Gebel Zeit block appears rigidly parallel with the N25°W Red Sea-Gulf of Suez trend and shows systematic long-term tilting away from the Gulf of Suez with at least five stages of Eocene through Miocene uplift, erosion of its eastern basement edge, and concomitant sinking and deposition on its western edge. The evidence points to early stage fault patterns inherited from the local structural grain of the Precambrian basement that pre-dated the principal Red Sea-Gulf of Suez evolution into its dominant N25°W tectonic trend during the Miocene