The fault-controlled skarn W–Mo polymetallic mineralization during the main India–Eurasia collision: Example from Hahaigang deposit of Gangdese metallogenic belt of Tibet

摘要: Abstract The Hahaigang W–Mo polymetallic skarn deposit is located in the central-eastern part of Gangdese tectono-magmatic belt Lhasa terrane, Tibet. was discovered 2007 with currently proven 46 million tons WO 3 ores, 12 million tons Mo and 1.31 million tons combined Cu–Pb–Zn at an average grade 0.20% , 0.07% Mo, 0.026% Cu, 0.49% Pb, 3.1% Zn. Ore bodies occur veins or disseminations, are confined within NE-striking Dalong fault zone which hosted by Lower-Permian Pangna Group dominantly quartz sandstone slate. Several granitic plutons exposed area known from drill-holes. Ages these determined using zircon U–Pb LA–ICP–MS method. For example, biotite monzogranite yields a 206 Pb/ 238 U– 207 U concordia age 58.66 ± 0.90 Ma weighted mean 57.02 ± 0.42 Ma. granite porphyry 109.1 ± 8.9 Ma 114.0 ± 2.6 Ma. 56.1 ± 1.1 Ma. Re–Os isochron 63.2 ± 3.2 Ma 5 molybdenite samples collected ores also obtained this study. geochronological data suggest that mineralization not temporally associated any dated igneous plutons. However, indicates might have occurred during main India–Eurasia collision initiated around 65 Ma. Microprobe analysis ilvaite occurs two generations reveals close relationship to Ca–Fe–F-rich hydrothermal fluids, were probably derived deeply-seated magmas. We ascent fluids strictly controlled ore-controlling zone, chemical interaction metasomatism between quartz-feldspathic host rocks produced collision. Although majority deposits reported be either pre- post-main collision, it evident study belt.