The mafic-ultramafic complex of Sikhoran (central Iran): a polygenetic ophiolite complex

The mafic-ultramafic complex of Sikhoran presents a long geological history, marked out by various magmatic, metamorphic and tectonic events. This history is much more complex than a simple ophiolite obduction over a continental margin. As early as the Upper Permian, following a mantle uprise in a Tethysian supra-subduction zone, the opening of a (back-arc?) basin in extensional/transtensional conditions provoked the intrusion of multiple gabbroic dykes, veins and plutons charged with fluids, through a mafic/ultramafic complex and its metamorphic cover. Several basins, characterised by abundant Submarine basaltic volcanism developed during Jurassic, whose feeding dykes may be represented by the diabase dyke swarms intruding the whole Sikhoran complex and its metamorphic cover.