Calcite U-Pb, pyrite Re-Os geochronological and fluid inclusion and H-O isotope studies of the Dafang gold deposit, South China

•Pyrite Re-Os and calcite U-Pb data support that gold mineralization at Dafang occurred at 158–149 Ma in late Jurassic.•Fluid inclusions and H-O isotope compositions reflect that ore fluids are intermediate- to low-temperature and intermediate- to low-salinity features, and are dominated by magmatic fluids with increasing volumes of meteoric waters at waning stage.•Fluid boiling and wall-rock sulfidation are proposed as the key factors for gold deposition.