An Early Cretaceous gold metallogenesis in the Wuhe area, Eastern Anhui province: Constraints from geology, fluid inclusion, H-O isotope and geochronology on the Hekou gold deposit

•Detailed observations combined CL imaging reveal three generations quartz in ore stage.•The key factor for the precipitation of Au was H2O-CO2-NaCl fluid immiscibility.•H-O isotopic data show ore fluids were mainly derived from magmatic fluids.•The Rb-Sr isochron age of gold-bearing pyrites is 128.1 ± 2.7 Ma.•The Hekou gold deposit shares similar mineralization feature with Jiaodong gold ore cluster.