Evolution and Stratigraphic Variability of a Rift Border Fault Segment: Sarbut El Gamal, Thal Fault, Hammam Faraun Fault Block, Suez Rift, Egypt

Chris Leppard¹, Rob Gawthorpe¹, and Mike Young^2
1 University of Manchester, Manchester, United Kingdom
² Norsk Hydro ASA, Bergen, Norway

The evolution and linkage of fault segments to form continuous, basin bounding normal fault zones is recognised as an important control on the stratigraphic evolution of rift-basins. We document the tectono-stratigraphic evolution of a fault segment from the Thal rift border fault, Hammam Faraun fault block, Suez Rift from the onset of rifting through to the rift-climax phase.

A number of dated stratal surfaces mapped around the syn-rift depocentre of the Sarbut El Gamal segment allow constraints to be placed on the timing and style of deformation, and the spatial variability of facies along this segment of the fault zone. The early syn-rift continental, Abu Zenima Formation, to shallow marine, Nukhul Formation show a pronounced westward increase in thickness controlled by a series of synthetic and antithetic faults up to 3 km west of present day Thal fault. The orientation of these faults controlled the location of fluvial conglomerates and overbank mudstones that infill incised valleys eroded into the pre-rift. During the deposition of the deep marine, Lower Rudeis Formation these faults became inactive as displacement became progressively localized onto the Thal fault. The thinning of syn-rift stratal units towards the ends of the segment and the distribution of coarse-gained density flows within the hangingwall basin highlights the control the evolving structure had on facies variability within the Lower Rudies. However, antecedent drainage pathways are also believed to exert a major control the location of a major submarine fan complex located in the centre of the fault segment.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005