The journey of the Band-e-Zeyarat ophiolite (Makran Accretionary Wedge, SE Iran) from the mid-ocean ridge to the accretionary complex: new insights from its sedimentary cover and associated basaltic dykes and sills

The Band-e-Zeyarat ophiolite (BEZO) sedimentary cover in the Makran Accretionary Prism (SE Iran) records a complex tectono-sedimentary evolution, extending from its formation at a mid-ocean ridge (MOR) setting to deformation in an accretionary prism. Stratigraphic and biostratigraphic data indicate the occurrence of a Valanginian transition zone sequence separating the volcanic sequence and pelagic sedimentary cover. The latter consists of lower Hauterivian cherty limestone passing upwards to upper Hauterivian-Barremian marl and limestone. The pelagic sedimentary cover continues with post-Barremian-Cenomanian (?) marls. Arenites are interlayered in the sedimentary cover; they are composed of rock fragments derived from volcanic-arc and continental margin settings. The BEZO sedimentary cover is intruded by dykes and sills showing enriched MOR basalt chemical affinity. Structural analysis indicates a polyphase deformation history that involved faulting and folding. Our multidisciplinary results indicate that the BEZO formed in a MOR setting and that it was subsequently overprinted by off-axis and within-plate magmatism as it spread away from this MOR. The Band-e-Zeyarat oceanic crust was incorporated into the Makran prism in the latest Late Cretaceous-Paleocene and was further deformed via strike-slip faulting along the dextral Minab-Sabzevaran fault during the Miocene-Pliocene.