The Arabian passive margin formed at the southern margin of the Neo‐Tethys ocean during the breakup of Pangea. In the Lurestan region of the Zagros mountain belt, the deformed Arabian continental paleo‐margin can be reconstructed as originally consisting of distinct crustal domains, including a proximal sector and a distal continental ribbon, separated by a deep‐water trough, known as the Radiolarite Basin. Such an architecture was shaped by the continental rifting process, thus reflecting timing and style of continent separation, which is generally assumed to have occurred during the Permo‐Triassic interval. This study reports evidence of syn‐sedimentary extensional faults, unconformities, and facies changes in the Mesozoic stratigraphic succession of the Lurestan region, which point to a major Jurassic extensional pulse. In detail, extension reached its climax at the end of the Early Jurassic, when tectonically driven drowning of the long‐lived Triassic to Early Jurassic carbonate platform led to the transition from shallow‐ to deep‐water environments in large areas of the inner margin, coevally with the development of the Radiolarite Basin. Our findings suggest a two‐step continental rifting in this area, with the first Permo‐Triassic phase predating an Early Jurassic one.

The 2017 M_w 7.3 Iran–Iraq earthquake occurred in a region where the pattern of major plate convergence is well constrained, but limited information is available on the seismogenic structures. Geological observations, interpretation of seismic reflection profiles, and well data are used in this paper to build a regional, balanced cross section that provides a comprehensive picture of the geometry and dimensional parameters of active faults in the hypocentral area. Our results indicate (i) the coexistence of thin- and thick-skinned thrusting, (ii) the reactivation of inherited structures, and (iii) the occurrence of weak units promoting heterogeneous deformation within the palaeo-Cenozoic sedimentary cover and partial decoupling from the underlying basement. According to our study, the main shock of the November 2017 seismic sequence is located within the basement, along the low-angle Mountain Front Fault. Aftershocks unzipped the up-dip portion of the same fault. This merges with a detachment level located at the base of the Paleozoic succession, to form a crustal-scale fault-bend anticline. Size and geometry of the Mountain Front Fault are consistent with a down-dip rupture width of 30 km, which is required for an M_w 7.3 earthquake.