Abstract: The Akexike Fe-Au deposit on the northern margin of the Junggar Basin occurs in the contact zone between volcanic rocks and tuffs of the Nanmingshui Formation. The orebodies are podiform, veined, and lenticular in form. The deposit has expereinced silicification, sericitization, chloritization, pyritization and carbonatization. Field evidence and petrographic analysis indicate two periods of metallogenesis: the volcanic-sedimentary period associated with the development of Fe mineralization and the hydrothermal period associated with Au mineralization. Liquid- and a few CO₂- rich inclusions characterize the volcanic-sedimentary period, whereas CO₂- and carbon (CH₄ and C₄H₆)- rich inclusions characterize the hydrothermal period. Volcanic-sedimentary period had NaCl-H₂O-CO₂ fluids with moderate temperature (major T_h of 180-320 ℃), low salinity (mainly 6-10 wt% NaCl_eq), and modereate to low density (0.59-0.98 g/cm³). Hydrothermal period has NaCl-H₂O-CO₂-CH₄ fluids with moderate temperature (major T_h of 220-320℃), low salinity (mainly 2-10 wt% NaCl_eq), and moderate to low density (0.55-1.03 g/cm³). Stable isotope analysis of quartz yielded values of -129.9‰ to -97.9‰ for δD, 7.9‰ to 12.3‰ for δ¹⁸O_SMOW, and -2.6‰ to 4.4‰ for δ¹⁸O_fluid, indicating that the ore-forming fluids were magmatic fluids mixed with seawater. δD, δ¹⁸O_SMOW, and δ¹⁸O_fluid values of the hydrothermal period are -129.8‰--102.6‰, 11.2‰-16.1‰, and 3.1‰-7.4‰, respectively, indicating that the ore-forming fluids were metamorphic water mixed with deeply circulated meteoric water. Combined with geological characteristics and fluids composition, the authors hold that Au mineralization of hydrothermal period was closely associated with CO₂-CH₄ fluids.