Structural Architecture and Paleofluid Evolution of Strike-slip and Normal Fault Zones, Jabal Qusaybah Anticline, Oman

The E-W-trending Jabal Qusaybah anticline is located at the western termination of the Salakh Arc, Oman Mountains. Jabal Qusaybah exposes the Cretaceous Natih carbonates, folded in a ~10 km long anticline characterized by a complex fault pattern which mainly includes (i) NE-SW left-lateral strike-slip and (ii) N-S extensional fault zones. The N-S striking extensional fault zones are perpendicular to the fold axis and best developed in the central sector of the anticlinal crest. They are geometrically confined within major NE-SW left-lateral strike-slip fault zones, forming an overall transtensional horsetail array. Collectively, our findings show that, in this transtensional setting, the fault zones acted as preferential pathways for fluid flow during folding, and that the central part of the anticline is the more dilatant sector. Furthermore, damage zone H/S ratio versus displacement diagram indicates that the structural position, rather than fault throw, is the parameter controlling the location of the more dilatants fault segments.