Volcanogenic massive sulphide (VMS) deposits in unconventional oceanic tectonic environments represent potential new targets for mineral resources such as Cu, Co, Ni, Zn, Au and Ag. Among these are the so-called ultramafic-hosted VMS deposits which form along low angle detachment faults in a variety of tectonic settings such as ocean-continent transition, mid-ocean ridge and supra-subduction. Such deposits have high potential in the Tethyan ophiolites, especially in the Alps, but their genesis remains poorly understood.