Structural study of fault damage zones in the area between Wadi Baba and Wadi Araba (eastern side of the Suez rift)

Abstract

The study area extends from Wadi Baba in the north to Gebel Ekma in the south in the eastern part of the Gulf of Suez rift. The present work is based on outcrop studies of damage zones of some normal faults which dissect the Nubia Sandstone in southwest Sinai Peninsula. In order to determine the damage zones and their related structures in the study area, the standard field equipment such as the compass, hand lens, diluted HCl, digital camera, measurement tape and satellite (Google) images were used. Field measurements were taken along scanlines extending across the faults. Each scanline was located perpendicular to the fault strike and within a single sand layer as much as possible in order to avoid the possible effects of different lithologies. Field recording of the position, azimuth, and dip of each structure (e.g. deformation bands, fractures, and minor faults) was done in addition to measurements of the apertures of these structures. In the study area, the Nubia Sandstone is widely exposed and highly dissected by different fault trends. 17 faults with different displacements ranging between more than 1 km and 50 cm have been studied in order to define the fault-damage zone geometry within the Nubia Sandstone. The Baba-Sidri area was covered by 5 stations and 12 scanlines have been spread across 8 faults with variable displacements in order to determine the fault-damage zones and their related structures. The first station covered two major faults in the area, the Baba border fault and Baba transfer fault. The damage zone of the Baba NNW-SSE oriented rift-parallel normal fault and its zone have been measured by two scanlines located in its footwall. Three regional cross sections constructed in order to find the relationship between the footwall and hanging wall damage zones.