Geology,fluid inclusion and stable isotope study of the Yueyang Ag-Au-Cu deposit,Zijinshan orefield,Fujian Province,China |
| |
| Institution: | 1. Beijing Research Institute of Uranium Geology, Beijing 100029, China;2. Key Laboratory of Orogen and Crust Evolution, Peking University, Beijing 100871, China;3. Zijin Mining Group Co. Ltd, Shanghang 364200, Fujian, China;1. Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China;2. Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;3. Graduate University of Chinese Academy of Sciences, Beijing 100049, China;4. Hainan Bureau of Geology, Haikou 570206, China;1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China;2. Dagang Branch of CNPC Ltd., Tianjin 300280, China;1. State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China;2. Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;3. State Key Laboratory of Geological Process and Mineral Resources, China University of Geosciences, Beijing 100083, China;1. State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China;2. University of Chinese Academy of Sciences, Beijing 100049, China;1. State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China;2. State Key Laboratory of Geological Processes and Mineral Resources, Faculty of Earth Resources, China University of Geosciences, Wuhan 430074, China;3. Collaborative Innovation Center for Exploration of Strategic Mineral Resources, China University of Geosciences, Wuhan 430074, China |
| |
| Abstract: | The large Yueyang Ag-Au-Cu deposit is commonly regarded as a low-sulfidation epithermal deposit in the Zijinshan orefield, Fujian Province, southeastern China. The Ag-Ag-Cu orebodies hosted in the Zijinshan granitic batholith are mainly stratoid and lens in shape, and controlled by a series of NW-trending listric faults with shallow dip angles. Four mineralization stages are recognized on the basis of mineral assemblage, ore fabrics, and crosscutting relationships of the ore veins, namely: pre-ore (pyrite + sericite + quartz ± chlorite), main Cu (chalcopyrite + pyrite + sericite + quartz ± bornite), main Ag-Au (Ag and Au minerals + pyrite + quartz + adularia ± calcite ± apatite ± chalcopyrite ± galena ± sphalerite) and post-ore (quartz ± chalcedony ± calcite) stages. Fluid inclusions (FIs) in the deposit include aqueous liquid-rich (WL-), aqueous vapor-rich (WV-), and minor carbonic (C-) and daughter mineral-bearing (S-) type ones. WL-subtype is the main inclusion type in the Yueyang deposit, accounting for more than 90% in proportion in each stage. Minor WV-subtype inclusions occur in both the main Cu and Ag stages, while the C-type and S-type ones are only observed in the main Cu stage. Fluid inclusion and H-O isotope study indicated that the ore-forming fluid of the main Cu stage is primarily magmatic vapor, which further underwent fluid boiling and mixing with meteoric water, while the ore-forming fluid of the main Ag stage is meteoric water-dominated, and the precipitation of silver and gold was mainly resulted from fluid boiling and the precipitation of other sulfides. On the basis of the aforementioned geological, fluid inclusion and stable isotope studies, we proposed a two-stage model for the Yueyang deposit, including a magmatic vapor-related porphyry type Cu mineralization and meteoric water-related low-sulfidation epithermal Ag-Au-Cu mineralization, although the porphyry Cu mineralization is very limited in scale. The mineralization and exhumation depths of the Yueyang deposit are estimated to be 448?527 m and 18?97 m, respectively. By comparison with the exhumation depths of other deposits in the Zijinshan orefield, it is suggested that more epithermal deposits could be found in the southwest of the orefield due to less uplift and exhumation therein. |
| |
| Keywords: | Fluid inclusion Stable isotope geochemistry Yueyang Ag-Au-Cu deposit Low-sulfidation Zijinshan orefield Fujian Province China |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
