Genesis of W-Mo mineralization in the Xiaoliugou and Ta'ergou ore fields, North Qilian Orogen (NW China): Constraints from fluid inclusions and S-Pb-H-O-Nd isotopes

•Magmatic fluid was of medium–high temperature-salinity and mixed by meteoric water.•Ore-forming materials were derived from granites and local sedimentary rocks.•The 450–420 Ma magmatic–hydrothermal event led to the W–Mo mineralization.•A two-stage multi-metal coupled mineralization model is proposed for the ore fields.