Melt- and fluid-inclusions studies in the Wunugetushan porphyry Cu–Mo deposit, NE China: Constraints on the separation of Cu and Mo

The Wunugetushan large porphyry Cu–Mo deposit in NE China is hosted by Mesozoic quartz monzonite and has a Mo-rich core Cu-rich rim space. In this paper, melt inclusions intrusions fluid different-stage veins were studied to explore potential parameters leading decoupling. Melt have rhyolitic compositions of 71.7–85.3 wt.% SiO 2 , 1.9–31.3 ppm Cu 1.7–2.6 Mo. Hydrothermal activity occurred over three stages: 1) Early Mo mineralization at high temperatures (543°C–560°C) CO -rich fluids intermediate salinity (11.0–17.3 NaCl equivalent), accompanied biotitization minor K-feldspathization; 2) Late involving high-salinity (up 77.0 equiv.) oxidized (400°C–454°C), with K-feldspathization sericitization; 3) A Cu-mineralization stage 45.6 -barren characterized temperature peaks 250°C–300°C 400°C–450°C, sericitization illitization. Given possible variations Cu/Mo ratios during magmatic redox conditions, pH, composition, the hydrothermal-fluid led separation Mo, we found that integrated including increased residual melt, state more acidic environment hydrothermal determine spatial two metals.