Rift Architecture and Growth Sedimentation across a Main Accommodation Zone, Northern Gulf of Suez-Egypt

By

 Darwish Khaled¹, Mohamed Darwish², Adel Sehim²

(1) GUPCO, Cairo, Egypt (2) Cairo University, Cairo, Egypt

 The Gulf of Suez rift shows asymmetry and reversal dip-polarity between centeral and northern segments. Onshore physiographic asymmetry and reversal locations of rift troughs are reflected by rift development across inherited deficit zones of wrenching-ridges that acted as rift-accommodation zones. The interference areas of rifting and deficit zones show narrow Early Miocene rift that gradually overcomes the effect of deficits and being wider by additional over-stepping fault-propagations in the older rift-shoulder.

The rift volcanics are geographically controlled by these deficit zones. The early syn-rift sediments show development of the rift-shoulder faults and deposition over flexure zones. Carbonates predominate in blocks close to the rift-shoulder faults, while reservoir clastics were charged from wadies on other side of the rift. Late Aquitanian-Burdigalian progressive rifting and accelerated fault subsidence were associated with divergent sedimentary-wedging of open marine source rocks and surface wadies continued charging reservoir clastics. Rift shoulder uplifting and shallowing of earlier troughs took-place in Langhian with manifestation of NE-trending fault segments.

The northern Gulf experienced exposure in Upper Miocene where deposition of evaporites diverges south-ward. Blocks south of deficit zones received continuous subsidence and deposition of thick salts. Renewed activities on the northern rift faults accommodated space for deposition of up to 7000 feet thick clastics of Pliocene-Holocene. This younger activity formulated petroleum traps where discoveries are located.