Geometry and kinematics of right‐lateral transpressional faults and growth folds, the western side of the Gulf of Suez, Egypt

Elaborated geological mapping and structural analysis of the Gulf of Suez's western side revealed two superimposed tectonic regimes; Late Cretaceous‐Early Eocene dextral transpression along ENE‐oriented deep‐seated faults and NE Oligo‐Miocene extension. Pre‐rift structures are represented by four ENE‐oriented right‐lateral strike‐slip deformation zones (DZ). Each DZ is defined by the ENE‐oriented right‐lateral strike‐slip faults, NE to ENE growth folds, and NW‐oriented normal faults. The orthogonal relation between the growth folds and NW‐oriented faults indicates their association to a strike‐slip tectonic regime. The tight overturned folds and the small angles between the growth fold axis and the principal deformation zone implies transpression rather than simple shearing. A transpressional tectonic regime with NW‐SE maximum principal stress (σ1) and NE‐SW minimum principal stress (σ3) were dominantly active during Late Cretaceous‐Early Eocene. The occurrence of three angular unconformities at different stratigraphic levels within the Upper Cretaceous‐Lower Eocene sedimentary sequences infer the deformation age. ENE anticlines have grown above the propagating deep‐seated transpressional faults, associated with continuous exhumation along their hinge zones and syntectonic deposition in the sub‐basins beyond their steep limbs. The cartoon illustrates the progressive growth parallel folds above propagating transpressional fault and the distribution of the syn‐kinematic sedimentary sequences. (a) Northward tilted continual passive margin after cessation of the Jurassic rifting; (b) Conicain to Campanian growth of ENE‐oriented anticlines above propagating transpressional faults and development of small basin in between the uprising anticlines, the sedimentary sequence onlap the crestal part of the Wadi Araba Deformation zone and little thinning above the uplifted growth folds. (c) Uplifting during Palaeocene high enough to make the uprising growth anticlines above Sea level or slightly submerged. (d) After a second phase of uplifting: A considerable sub‐basin has been developed and received Early Eocene sediments. (e) Post Early Eocene, several ENE‐oriented incised valleys have been developed guided by the pre‐existing deformation zones and associated growth folds, the onset of the Gulf of Suez rifting and the uplift of its margin was responsible for deeply incised valleys along the pre‐existing Upper Cretaceous‐Eocene deformation zones.