Gold deposition and resource potential of the Linglong gold deposit, Jiaodong Peninsula: geochemical comparison of ore fluids

•Medium temperatures, low salinity, and CO2-rich H2O–CO2–NaCl ± CH4 orefluids.•Gold deposition mainly led by fluid immiscibility at 242–54 MPa and 348–269 °C.•Stage 2 ores have higher CO2 and CH4 contents, and more intense fluid immiscibility than stage 3 ores.•Gold mineralization likely occurred at a depth of 5.4–9.0 km, deep gold exploration is expectable in Linglong.