Ore genesis of Badi copper deposit, northwest Yunnan Province, China： evidence from geology, fluid inclusions, and sulfur, hydrogen and oxygen isotopes

作     者：Hejun Yin Jianguo Huang Tao Ren 

作者机构：Kunming University of Science and Technology Kunming 650093 China 

出 版 物：《Acta Geochimica》 (地球化学学报（英文）)

年 卷 期：2018年第37卷第4期

页      面：559-570页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：jointly supported by the Geological Survey of China (Grant No. 1212011140050) the National Natural Science Foundation of China (Grant No. 41663006) 

主　　题：Badi copper deposit Fluid inclusion Sulfurisotope Hydrogen and oxygen isotope Ore genesis 

摘      要：The Badi copper deposit is located in Shangjiang town, Shangri-La County, Yunnan Province. Tectonically, it belongs to the Sanjiang Block. Vapor-liquid two-phase fluid inclusions, CO2-bearing fluid inclusions, and daugh- ter-beating inclusions were identified in sulfide-rich quartz veins. Microthermometric and Raman spectroscopy studies revealed their types of ore-forming fluids： （1） low-tem- perature, low-salinity fluid; （2） medium-temperature, low salinity CO2-bearing; and （3） high-temperature, Fe-rich, high sulfur fugacity. The δ^18O values of chalcopyrite- bearing quartz ranged from 4.96‰ to 5.86%0, with an average of 5.40%0. The δD values of ore-forming fluid in equilibrium with the sulfide-bearing quartz were from - 87‰ to - 107‰, with an average of - 97.86%0. These isotopic features indicate that the ore-forming fluid is a mixing fluid between magmatic fluid and meteoric water. The δ^34S values of chalcopyrite ranged from 13.3‰ to 15.5‰, with an average of 14.3‰. Sulfur isotope values suggest that the sulfur in the deposit most likely derived from seawater. Various fluid inclusions coexisted in the samples; similar homogenization temperature to different phases suggests that the Badi fluid inclusions might have been captured under a boiling system. Fluid boiling caused by fault activity could be the main reason for the mineral precipitation in the Badi deposit.