Structural architecture and tectonic evolution of Haimour block, Gulf of Aqaba, Egypt: An example of multiphase deformed stepover

Abstract

A unique outcrop of a dilational NNE-oriented stepover takes place between two left-stepping NE sinistral faults at the Haimour block along the western margin of the Gulf of Aqaba basin. Detailed surface geological mapping was achieved in order to unravel structural architecture and deformation style of the Haimour stepover (HSO). The HSO comprises N- to NNE- oriented transtensional and normal faults that affect all the sedimentary succession including the syn-kinematic sediments. Contrarily, the southern part includes a remarkable push-up structure that comprises NNE-to NE-oriented compressional structures affecting the Upper Cretaceous rock units. The southern end of the HSO is marked by a NNE-oriented Principal Displacement Zone (PDZ), which encloses NNE- and NE-oriented sinistral faults. Structural analysis of field data considering the previous analogue and numerical models indicates a well-developed basin side-walls and basin cross-fault zone of the HSO. Additionally, divergent-oblique slip model (30° transtension) is suggested for the HSO. The proposed tectonic model of the HSO revealed that the initiation of the pull-apart basin took place during the Oligocene times concurrently with the opening of the Red Sea rift and continued to the Post-Miocene times. The outcomes of this study provide a model for architecture and evolution of similar structural style along Gulf of Aqaba and Dead Sea Transform. Moreover, the proposed architecture of the HSO should provide an analogue for subsurface mapping and exploration at strike-slip zones.