Timing and ore formation of the Xiaokele porphyry Cu (–Mo) deposit in the northern Great Xing’an Range, NE China: Constraints from geochronology, fluid inclusions, and H–O–S–Pb isotopes

•The newly discovered Xiaokele Cu (–Mo) deposit is a typical porphyry deposit.•Cu (–Mo) mineralization is associated with Late Jurassic granodiorite porphyry.•Ore-forming fluids were magmatic in origin and mixed with meteoric water gradually.•Fluid cooling was the primary factor that controlled Cu precipitation.