Ore-Forming Fluid Characteristics of the Dayingezhuang Gold Deposit, Jiaodong Gold Province, China |
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Authors: | Liqiang Yang Jun Deng Chunying Guo Jing Zhang Shaoqing Jiang Bangfei Gao Qingjie Gong Qingfei Wang |
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Affiliation: | State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing, China |
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Abstract: | The Dayingezhuang gold deposit is located in the central part of the Zhaoping Fault Zone, which is one of the most important gold-hosting faults in the Jiaodong gold province of China. Dayingezhuang is a typical large-scale shear zone-hosted disseminated gold deposit with superimposed silver mineralization. Fluid inclusion (FI) petrography and microthermometry, and analysis of oxygen and hydrogen isotopes for fluid inclusions were conducted to determine the characteristics of the ore-forming fluids and the processes of silver mineralization. Microthermometry data of FI indicated that ore-forming fluids are characterized by low salinity and low density. Homogenization pressures of FI are estimated at 20 × 105–220 × 105 Pa. The change in ore-forming fluids from K2SO4 type to NaCl type indicates the superposition of two hydrothermal mineralizing events. Ore-forming fluids were dominated by magmatic components in the early mineralization period, and affected by meteoric waters in the late period. Gold may have been transported as Au-S or Au-Cl complexes, whereas silver was transported as Ag-Cl complexes. Early fluid boiling and later fluid mixing are thought to be two of the main factors causing the deposition and superimposing of gold and silver to form the large deposit. |
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Keywords: | Dayingezhuang gold deposit fluid inclusions Jiaodong gold province China superimposed mineralization |
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