Lithospheric structure beneath the south-eastern Zagros Mountains, Iran: recent slab break-off?

Integrated lithospheric modelling, based on the combined interpretation of gravity, geoid and topography data sets, highlights a previously undocumented lithospheric thinning beneath the Zagros collisional belt (Iran), which we propose to relate to recent slab break-off at the continent-ocean transitional lithosphere. Recent published data on the distribution of seismicity at depth support this interpretation. In agreement with other published models for the Zagros Mountains, the overlying crust exhibits, by contrast, a noticeable thickening, reaching a maximum of 52 km. The consequent thermal uplift expected from slab break-off is suggested to have modified the Zagros wedge taper and triggered the recently documented switch from thin-skinned to thick-skinned deformation in the Zagros Fold-Thrust Belt.