Superposed tectonic regimes in west Beni Suef basin, Nile Valley, Egypt: Implications to source rock maturation and hydrocarbon entrapment

Abstract

Abstract The present study contributes to the knowledge of the structural architecture and kinematic evolution of the West Beni Suef basin, by means of detailed seismic interpretation. This basin is one of several in a NW–SE oriented Early Cretaceous basin system occurring at the northeast corner of the African plate. We used the patterns of growth sedimentation above the limbs of growth folds, and in the downthrows of normal faults as kinematic indictors. Two phases of strike slip tectonics during the Santonian and Campanian–Maastrichtian superposing an Early Cretaceous rifting are verified in this basin. The Santonian and Campanian–Maastrichtian strike slip tectonics are represented by an E–W strike slip fault zone associated with NE growth folds and NW growth normal faults as well as ENE, WNW and E–W strike slip fault segments. The Early Cretaceous rifting facilitates the maturation of the deeper source rocks such as Lower Cretaceous shales of the Kharita Formation. Moreover, the strike slip tectonic events played a major role in the maturation of the shallow depth Cenomanian–Turonian Abu Roash “F” Member through entrapment in a releasing bend at the central part of the study area. The structures associated with the two tectonic regimes include, horsts, normal fault propagation folds and strike slip related anticlines, which formulated the main structural traps in the study area.