WANG Ren-ke¹, Dilixiati·MAIMAITI^1*, WANG Yong², WANG Jun-lin¹, LIU Bo², LIN Cai-xiang², Kayishaer·ERESI¹, BAI Yu-xiu¹

(1. College of Geology and Mining Engineering, Xinjiang University, Urumqi 830047, China;
2. West Gold Karamay Hatu Gold Limited Liability Company, Karamay 834000, China)

Abstract: The Hatu gold deposit is located in a narrow and long zone sandwiched between the Hatu and Anqi faults in the western margin of the Junggar basin, northern Xinjiang. The deposit is controlled by the Anqi fault and surrounding secondary faults. There are mainly two kinds of gold ore bodies, including the quartz vein type and altered rock type. There ore-forming stages in the Hatu gold deposit has been identified based on the relationships of mineral paragenesis and cross-cutting veins. The study of fluid inclusions in quartz veins shows that there are three types of fluid inclusions in ores of the deposit. Type Ⅰ is a liquid-rich inclusion with two phases (L+V). Type Ⅱ is a vapor-rich inclusion with two phases (L+V). Type Ⅲ is a CO2-H2O-bearing inclusion with three phases. The Type I, Type II and Type III inclusions are all developed in the early stage. Their homogenization temperatures vary from 293 to 379 ℃, and their fluid salinities vary from 1% to 5.7% NaCleqv. The Type I, Type II and Type III inclusions are also developed in the middle stage (the main ore-forming stage). Their homogenization temperatures vary from 213 to 291 ℃ and their fluid salinities vary from 0.5% to 5.9% NaCleqv. In the late hydrothermal stage, only Type I inclusions are developed, with their homogenization temperatures ranging from 148 to 216 ℃, and the fluid salinities ranging from 1.4% to 4% NaCleqv. Based on the pressure and depth calculation, the metallogenic pressures of inclusions vary from 47 to 97 MPa and the corresponding depths are ranging from 4.8 to 9.4 km. The δ18OV-SMOW values of the quartz vary from 20.4‰ to 21‰. The calculated δ18OH2O values of the balanced water vary from 8.6‰ to 14.7‰. The δ18DH2O value of fluid the inclusion fluids in quartz are ranging from -77.2‰ to -64.5‰. Compared with results of the previous studies, we have proposed that the Hutu gold deposit is an orogenic type medium-low temperature hydrothermal gold deposit, and the ore-forming fluid is a low salinity and low density CO2-H2O system with dominant meteoric water influenced by magmatic and metamorphic hydrothermal waters.

Keywords: The Hatu gold deposit; orogenic gold deposit; fluid inclusion; hydrogen isotope; oxygen isotope

ACTA MINERALOGICA SINICA Vol. 39, No.1, 2019, page 83-91