Mineralization series and resource potential of subvolcanic-hydrothermal Au (Ag) deposits in central Fujian

Abstract：Central Fujian is an Au-Ag ore deposit concentration area in Fujian Province, and mineralization mainly occurred during Late Jurassic subvolcanic activity. Three sources (mineral, heat and water) were prerequisites for the formation of subvolcanic-hydrothermal Au (Ag) deposits and compounding of the NW and NE sets of structure was the key to the localization of ore deposits. Three sub-series (namely, diabase-dioritic porphyrite, dacite porphyry and rhyolite sub-series) of the subvolcanic-hydrothermal Au (Ag) mineralogenetic series formed in their respective related tectonic environments—the fault uplift zone, uplift in a depression and subbasins in a depression. From above to downward, there occur vertical zoning of industrial ore deposit types, i.e. the fine- and very fine-grained disseminated type deposit, quartz vein type deposit, fractured zone alteration type deposit, cryptoexplosive breccia type deposit and subvolcanic type deposit. The Au resource potential is estimated at more than 50 tons in the study area.