Preliminary sequence stratigraphy and tectonic evolution of the Tokar Delta, (Southern Sudanese Red Sea)

Abstract

The study area comprises about 2500sq.Kms. From the seismic data acquired by the Oil Companies (Chevron 1975-76 Total 1980 and IPC 1992), thirty two seismic lines were selected Fig (2). Also synthetic seismograms of Suakin-1, Bashayer-1 A and Bashayer-2A wells are used. The stratigraphy and sedimentation of the Sudanese Red Sea can be placed into four major tectonic phases, Pre-rifting stratigraphy, Syn-Rift Pre-Salt Stratigarphy, Salt Phase and Syn-Rift Post Salt Stratigraphy. Basic concepts of seismic stratigraphy are applied, the lower most sequence (Mukawar, Hamamit and Mughersum group) overlies and onlaps the basement complex is Relatively uniform throughout the area, the evaporite sequence deposited during the cycle of sea level rise and fall, indicating a change in climate and prolonged period of desiccation, this sequence is composed of Belayim and Dungunab Formation. The Dungunab Formation is a listric glide surface. The third sequence contains three system tracts, the lowermost is a low stand, the middle is a transgressive, and the upper is a high stand system tract. This sequence is known as the Zeit Formation. The uppermost sequence is a thick sedimentary unit which is composed mainly of a mixture of elastics and carbonates of Abu Shagara Group. The region witness extensive studies concerning the behavior of the tectonism and the evolution of the Red Sea and its adjoining. Tokar Delta is a part of a NW-SE trending fault-controlled sedimentary basin.