Seismic imaging of sub-circular salt-related structures: evidence for passive diapirism in the Straits of Hormuz, Persian Gulf

A detailed interpretation of seismic data has been carried out to analyse salt diapirism in the Straits of Hormuz in the Persian Gulf. Salt diapirs in the Zagros Foldbelt are mainly characterized by structures formed by mobilization of the Cambrian Hormuz salt as reactive diapirs during the Late Cretaceous–Tertiary Zagros orogeny. Interpretation of available data in the straits of Hormuz suggests that diapirs of Hormuz salt grew actively until the Early Miocene and then continued to rise passively by downbuilding of surrounding sediments until the present time. The syn- to post-Miocene Zagros sedimentation played a major role in passive diapirism. Sedimentation of the thick Lower Miocene deposits led to greater subsidence of the basin and passive diapirism of the Early Miocene Fars salt as well as further inflation of the Hormuz salt into neighbouring structures. Seismic mapping of the salt-related structures as well as observations in the overlying sediments, such as thickness variations and faulting, also constrain the Late Tertiary passive diapirism of the Hormuz and Fars salt in the Zagros.