Structural setting of Gebel Ataqa area, Gulf of Suez, Egypt: Implications for rift-related fault array

Abstract

Gebel Ataqa is a triangular rift-related tilted fault block bounded from all sides by steeply dipping normal faults. The exposed rock units in Gebel Ataqa area range in age from Cretaceous to Recent. Cretaceous outcrops are restricted to the eastern escarpment; however, most of the exposures of the Gebel Ataqa area belong to Middle Eocene dolomitic limestone. The Upper Eocene outcrops are scattered at the foot of Gebel Ataqa and are faulted down against the Middle Eocene in the northern part of the study area. The Miocene outcrops are scattered in the southwestern low lands of Gebel Ataqa on the both sides of WadiHagul Road. The structural setting of the Gebel Ataqa is related to Oligocene-Miocene rift tectonics. The major fault systems mapped in Gebel Ataqa area are NW-SE oriented faults, as well as E-W elongated fault belts including en echelon faults located in the northwestern part of Gebel Ataqa. In the southwestern part of the study area, the interference of the NW-SE oriented faults and E-W oriented faults form a zigzag fault array. The majority of the mapped faults are steeply dipping. The E-W en echelon faults are dipping at 80° to vertical, however, the NW-SE oriented faults and their associated E-W oriented faults range in dip from 65° to 75°. The E-W and NW-SE oriented faults' systems are of the same age (Oligocene-Miocene and rejuvenated in the post-Miocene time). The E-W en echelon fault belts are related to the rejuvenation of deep-seated E-W oriented faults.