Geology, geochemistry, fluid inclusions, and H–O–C–S–Pb isotope constraints on the genesis of the Atash-Anbar epithermal gold deposit, Urumieh–Dokhtar magmatic arc, central-northern Iran

•Gold precipitation occurs due to destabilization of Au-bisulfide complexes during wall rock sulfidation (deceasing of ƩStotal) and fluid phase separation.•The Atash-Anbar deposit can be classified as an IS epithermal gold deposit.•The ore-forming fluids, sulfur, and metals were derived primarily by devolatilization of the volcanic and subvolcanic magmatic rocks.