Abstract:The Axi and Tawuerbieke gold deposits, located in the Tulasu basin, Western Tianshan, Xinjiang, are adjacent to each other but with different styles of mineralization. The petrography and SEM-spectrum analysis show that the metal minerals in ores from Axi are mainly pyrite, arsenopyrite and marcacite, whereas chalcopyrite, bornite, tetrahedrite, tennantite and aarite were commonly developed at Tawuerbieke apart from the pyrite. The fluid inclusions in both deposits are aqueous inclusions with low temperature and salinity. The thermoelectric conduction type of pyrite from Axi is characterized by P type, and the calculated temperatures vary from 160 °C to 240 °C (Average 195 °C). By contrast, the thermoelectric conduction type of pyrite from Tawuerbieke is dominative of N-P mixed type, and the corresponding temperatures of N and P type pyrite are between 300 °C and 380 °C (average 362 °C) and between 80 and 240 °C (average 137.0 °C), respectively. Based on the mineral assemblages, ore textures, fluid inclusions and thermoelectric characteristics of pyrite, it is inferred that the ore-forming temperature of Tawuerbieke is significantly higher than that of Axi. The δ34S values of pyrite separates in ores from Axi and Tawuerbieke gold deposits range from -4.0‰ to 5.3‰ (average 0.7‰) and 0.6‰ to 4.7‰ (average 2.5‰), with in-situ δ34S values of Au-bearing pyrite ranging from -2.6 to 5.6‰ (averge 2.4‰) and 1.9‰ to 3.8‰ (average 2.9‰), suggesting that these two deposits display consistent sulfur source, namely the magma sulfur. The Pb isotopic compositions of pyrite from these two deposits are both similar to those of hosting volcanic rocks and granite porphyry, indicating that the ore-forming materials were sourced from the hosting magmatic rocks. Fluid inclusions, diagnostic minerals and ore textures indicate that fluid boiling was the main precipitation mechanism for the Au mineralization at Axi. Combined evidence from the occurrence of orebodies, mieral assemblage, ore textures, hydrothermal alteration and ore-forming materials suggest that Axi is typical of low-sulfidation epithermal Au deposit, whereas Tawuerbieke belongs to the transitional subepitehrmal style between porphyry and epithermal mineralization. Based on the characteristics of pyrite thermoelectric conduction type, denudation extent of orebody, ore textures, mineral assemblages and intrusion sizes, it can be inferred that the Axi and Tawuerbieke experienced different extents of erosion (Axi＜Tawuerbieke) and that there is exploration potential for concealed porphyry Cu-Au mineralization beneath the Tawuerbieke.