Multiple mineralization events in the eastern Tianshan district, NW China: Isotopic geochronology and geological significance

The eastern Tianshan district occupies the middle of the Central Asian Orogenic Belt and has great economic potential for polymetallic mineralization. More than 20 medium to large ore deposits have been discovered in this region since the late 1980s. The timing of mineralization was previously thought to be Hercynian, but, Mesozoic ages for intrusions and mineralization have been repeatedly reported in recent years. Based on geochronological data and regional geological evidence, it is suggested that the mineralization in the eastern Tianshan was formed during multiple events. The mineralization processes are related to an subduction-island arc stage (∼360–320 Ma) with porphyry-type and volcano-sedimentary copper deposits, a collisional-accretionary stage (∼300–280 Ma) with orogenic-type gold deposits, a post-collisional-extension stage (∼280–245 Ma) with mafic–ultramafic copper–nickel and epithermal gold deposits, and an intracontinental extensional stage (∼240–220 Ma) that gave rise to the Jinwuozi gold deposit, Xiaobaishitou skarn W–Mo deposit and Baishan porphyry Mo–Re deposit.