Fluid inclusion, siliceous rock geochemistry of Shewushan lateritic gold deposit, Hubei Province, eastern China: Implication for the genesis of primary orebody  

作　　者：WANG Minfang ZHENG Youye XU Rongke LIU Yunguang XIAO Fan CHENG Shanwen SUN Xiangmin 

机构地区：[1]Faculty of Earth Resources,China University of Geosciences,Wuhan 430074,China [2]State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences [3]Institute of Geological Survey,China University of Geosciences [4]Sichuan Institute of Nuclear Geology [5]Nanjing Center,China Geological Survey [6]Shewushan Gold Mine Co. Ltd [7]No. 4 Geological Party,Hubei Bureau of Geology and Mineral Resources

出　　处：《Chinese Journal Of Geochemistry》2014年第1期65-76,共12页中国地球化学学报

基　　金：financially supported jointly by the National Natural Science Foundation of China (No. 40902026; No 41272097);the State Key Laboratory of Geological Processes and Mineral Resources (No. GPMR 201006);the Special Fund for Basic Scientific Research of Central Colleges; China University of Geosciences (Wuhan) (No. CUG120702);the Shewushan Gold Mine Co. Ltd and No. 4 Geological Party;Hubei Bureau of Geology and Mineral Resources for the field support

摘　　要：The Shewushan gold deposit is located 16 km southwest of Jiayu County, Hubei Province, eastern China, which is the largest lateritic gold deposit in Asia, consisting of a series of mineralized faults containing gold grades of 1.0–19.5 g/t set within a larger, lower-grade(0.2–1.0 g/t) zone. According to the fluid inclusions study, the homogenization temperature ranges from 70–350℃, and concentrates between 140–220℃. The laser Rama results show that the CO2 and CH4 exist in mineralized fluid. In addition, the major and trace element and REE geochemical data show that the genesis of the siliceous rocks is hydrothermal genesis, formed by mineralized fluid bearing SiO2 transmitted along faults to the surface, and replace the carbonate rocks to begin deposition. Primary gold mineralization is attributed to hydrothermal activity that followed the main period of tectonic deformation of the Indosinian orogeny, which caused the regional detachment regime in southeast Hubei. The reversed fold and the fault system formed the fluid migration channel in the Shewushan area. EPMA results show that Au exists in arsenopyrite(850×10-6–1550×10-6 Au) and pyrite(470×10-6–1340×10-6 Au). Therefore, based on the above results and combined with the field observation, we suggest that the genesis of primary orebody in Shewushan deposit is carlin type, while not weathered residual type.The Shewushan gold deposit is located 16 km southwest of Jiayu County, Hubei Province, eastem China, which is the largest lateritic gold deposit in Asia, consisting of a series of mineralized faults containing gold grades of 1.0-19.5 g/t set within a larger, lower-grade （0.2-1.0 g/t） zone. According to the fluid inclusions study, the ho- mogenization temperature ranges from 70-350℃, and concentrates between 140-220℃. The laser Rama results show that the CO2 and CH4 exist in mineralized fluid. In addition, the major and trace element and REE geochemical data show that the genesis of the siliceous rocks is hydrothermal genesis, formed by mineralized fluid bearing SlOE transmitted along faults to the surface, and replace the carbonate rocks to begin deposition. Primary gold mineraliza- tion is attributed to hydrothermal activity that followed the main period of tectonic deformation of the Indosinian orogeny, which caused the regional detachment regime in southeast Hubei. The reversed fold and the fault system formed the fluid migration channel in the Shewushan area. EPMA results show that Au exists in arsenopyrite （850× 10^-6-1550× 10-6 Au） and pyrite （470× 106-1340 × 10-6 Au）. Therefore, based on the above results and combined with the field observation, we suggest that the genesis of primary orebody in Shewushan deposit is carlin type, while not weathered residual type.

关 键 词：稀土元素地球化学 红土型金矿床 流体包裹体 中国东部 湖北省 硅质岩 矿体 起源 

分 类 号：P618.51[天文地球—矿床学] P618.130.2[天文地球—地质学]