Oblique oceanic opening and passive margin irregularity, as inherited in the Zagros fold-and-thrust belt

The Zagros fold-and-thrust belt of SW Iran represents deformation of the former Arabian passive margin since Permian-Triassic opening of the Neo-Tethys ocean. The Zagros belt is characterized by a present-day structural salient-recess setting inherited from past marginal embayment-promontory geometry, which was involved in discontinuous ophiolite obduction and diachronous continental collision. We examine outcrop-scale Mesozoic extensional brittle tectonics, preserved as syn-depositional normal faults within the folded strata, in terms of stress tensor inversion. The result is then integrated with belt-scale isopach, seismic and topographical data to delineate the geometry of a major irregularity along the passive margin originating from oblique oceanic opening. The implication of this configuration within the tectonic framework of oceanic closure is discussed.