Metallogenesis of the Hengjiangchong gold deposit in Jiangnan Orogen, South China

•Orebodies of Hengjiangchong Au deposit (Jiangnan Orogen) are controlled by NW-trending faults.•H–O–S–Pb isotopes indicate a metamorphic source for the ore fluid and components.•Fluid inclusions indicate that fluid immiscibility and fluid–rock interactions likely promoted Au deposition.•The Hengjiangchong Au deposit is best classified as orogenic type, instead of intrusion-related.