Structural evolution and Cenozoic tectonostratigraphy of the Cairo-Suez district, north Eastern Desert of Egypt: Field-structural data from Gebel Qattamiya-Gebel Urn Reheiat area

摘要

Detailed field mapping reveals that continental rifting is strongly deforming the Gebel Qattamiya-Gebel Urn Reheiat area and the entire Cairo-Suez district, in north Eastern Desert of Egypt. Rift-related structures are predominantly represented by E to WNW, NNW and NW oriented faults. The E to WNW oriented faults are small and build up the Gebel Qattamiya en echelon fault belt, whereas the faults trending NNW and NW establish a pervasive horst and graben structural style involving some rhomb-shape horsts as Gebel Qattamiya (GQRH), Gebel Urn Reheiat (GURRH) and south Gebel Urn Reheiat (SGURRH). Rock units of the Eocene succession and Oligocene sediments are well exposed and highly controlled by rift related structures. Rifting was developed through two rift-phases; initial and major ones. The initial phase (a newly recognized phase in this contribution) has been occurred in Late Eocene (Priabonian), while the main phase was prevailing during Late Oligocene-Early Miocene time and is characterized by hydrothermal veins and basaltic eruptions. Continental transtension in the Cairo-Suez district, including the study area, was probably synchronous with a major tectonic stage (Pyrenean-Atlasic movement) of continental collision between African-Arabian and Eurasian plates in Late Eocene-Oligocene time.