Abstract:

The Sarbulake gold deposit, located in the Kalatongkes island arc zone in the northeastern margin of the Zhuigaer Basin, occurred in the Sarbulake shear zone, which is a secondary structure of the NWWtrending Erqisi compressive tectonic zone to the north. Based on deformationhydrothermal alterationmineral assemblages, the structuralmineralization process can be divided into four stages: 1) the ductile deformationpyritesilicification stage; 2) the ductilebrittle deformationpyritearsenopyritequartz stage; 3) the stockwork quartz stage (polymetallic sulfide stage); and 4) the quartzcarbonate stage. The fluids in the early and middlestage were rich in CO2 (CH4) (represented by the carbonic inclusions) and had high CO2/H2O ratios. The homogenization temperatures (Th) of inclusions in the stage 1 are concentrated in the ranges of 290350 ℃ and 200269 ℃, those in the stage 2 are mainly in the range of 204358 ℃ and 170203 ℃, whereas the homogenization temperatures in the stage 3 are concentrated in 215310 ℃. Primary aqueous inclusions are associated with carbonic inclusions in the early and middle stages, while secondary aqueous inclusions also occurred widely in the stage 1, 2 and 3. These secondary inclusions probably represent meteoric water during crustal uplift in the late metamorphism. The evolution from mesothermal, CO2(±CH4)rich fluids to epithermal, aqueous fluids appears to have been accompanied by the transition from compressive, ductile regime to extensional, brittle regime along the Erqisi orogen. The Sarbulake gold deposit is similar to most orogenic gold deposits, with the mineralization process being mostly in the latetectonic stage and accompanied by the transition from compressive to extensional stress regimes.

Key words: fluid inclusions, orogenic gold deposit, tectonicfluid, Saerbulake gold deposit