THE GEOLOGY OF THE AREA BETWEEN WADI WARDAN AND WADI GHARANDAL, EAST CLYSMIC RIFT, SINAI, EGYPT

The area between Wadi Wardan and Wadi Gharandal lies within the rift of the Gulf of Suez, the Clysmic rift, and is part of an elongated zone of outcropping Miocene deposits which show considerable persistence in a NNW to SSE direction, but which undergo frequent and rapid facies changes from W to E. The rocks are folded into a series of asymmetrical anticlinal flexures and synclines, sometimes faulted, whose axes trend NNW to SSE. They prove to be drape structures overlying pre‐Miocene blocks which are generally tilted. Block faulting began during Oligocene times and persisted through Miocene into the post‐Miocene period. The blocks dip westwards, towards the centre of the rift, and are generally bounded by antithetic faults. The structures described in this paper are typical for the whole region of the Clysmic rift. There are no beds of Oligocene age and no igneous rocks, either of extrusive or of intrusive origin, occur in association with Miocene or later deposits. The area has proved to be important economically. Three oilfields have been discovered there–Sudr (which lies some kilometres N of Wadi Wardan) in 1946, Ras Metarma in 1948, and Asl in 1949. In each case, the reservoir rock is found near the base of the Miocene or in Eocene limestone at or near the top of a Wdipping block of pre‐Miocene strata. Marls and gypsum or anhydrite deposits invariably form the capping rock. Copyright © 1979, Wiley Blackwell. All rights reserved