Active transcurrent fault system along the north African passive margin

Abstract

Abstract Along the southern boundary of the eastern Mediterranean extends a WNW-trending narrow zone, about 1000 km long, of possible transcurrent faulting. It terminates on both sides at areas of crustal extension, the Tyrrhenian Sea on the west-northwest and the Gulf of Suez on the east-southeast. From the southern Tyrrhenian Sea the fault zone runs through the Strait of Sicily rift zone, the Ionian Sea, the base of the continental margin of eastern Lybia and western Egypt, into the land area through the apex of the Nile Delta and eventually into the Gulf of Suez. Studies of the fault pattern in the Strait of Sicily indicate that the rifting processes there are associated with a major dextral shear zone. Right-lateral movement is also consistent with the deformation along the southeastern extension of the fault zone: i.e., the sense of offset of a series of bathymetric depressions located along the base of the continental margin of eastern Lybia and western Egypt which we interpret as pull-apart basins formed by transcurrent faulting. Crustal structure may play an important role in controlling the location of the fault zone. On both ends, adjacent to the zones of crustal extension in the Tyrrhenian Sea and the Gulf of Suez, the fault is located within a continental crust, in the Strait of Sicily and in northern Egypt. In between, in the Ionian Sea and at the base of the continental margin of eastern Lybia and western Egypt, it is located in between provinces of continental crust on the south and oceanic crust on the north.