Chronology and origin of VMS deposits in Xinjiang, NW China

VMS deposits in Xinjiang, NW China are widespread in the Altay, Tianshan and West Kunlun orogenic belt, mainly formed during the Proterozoic rifting and Phanerozoic post-orogenic extension and are related to the bimodal volcanism. The VMS deposits are middle and small in scale. According to assemblages of metallogenetic elements, they can be divided into four types (Cu-Zn, Cu-S, Pb-Zn-Cu and Pb-Zn types) with the Cu-Zn and Pb-Zn types being the most important ones. Research of isotopic chronology shows that the VMS deposits in Xinjiang were formed during the Proterozoic, Ordovician, Deovonian, Carboniferous and Permian periods and usually underwent multi-stage mineralization, especially the large-sized deposits usually have post-volcanic superimposed mineralization by tectonomagmatic or metamorphic hydrothermal metal-logenic fluids.