Mineralogy, geochemistry and fluid inclusions of the Qinglong Sb-(Au) deposit, Youjiang basin (Guizhou, SW China)

•New Au mineralization in the Qinglong Sb deposit (SW China) is reported.•Ore-forming fluids were of mixed H2O-NaCl-hydrocarbon ± CO2 aqueous fluids.•Sulfur in the ore-forming fluids was dominantly magmatic-derived.•Fluid mixing is a key factor for the extensive stibnite precipitation.•Stibnite precipitation destabilized the AuHS0 complexes and caused Au precipitation.