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Geoscience ›› 2020, Vol. 34 ›› Issue (02): 254-265.DOI: 10.19657/j.geoscience.1000-8527.2020.02.04

• Ore Deposits • Previous Articles     Next Articles

Ore-forming Fluid Characteristics and Genesis of the Wudaogou Gold Deposit in Dongning County, Heilongjiang Province

FANG Yan1(), HE Mouchun1,2, DING Zhenju1, XU Yiran3, WEI Lianxi4()   

  1. 1. School of Earth Resources, China University of Geosciences, Wuhan, Hubei 430074, China
    2. National Demonstration Center for Experimental Mineral Exploration Education (China University of Geosciences (Wuhan)), Wuhan, Hubei 430074, China
    3. Department of Land Resources of Hunan Province, Changsha, Hunan 410004, China
    4. Heilongjiang Institute of Nonferrous Metal Geological Survey, Harbin, Heilongjiang 150090, China
  • Received:2019-01-16 Revised:2019-11-18 Online:2020-05-25 Published:2020-05-25
  • Contact: WEI Lianxi

Abstract:

The Wudaogou gold deposit is located at Dongning County, Heilongjiang Province, south part of Taipingling Au-Cu polymetallic metallogenetic belt. Au mineralization is mainly presenting as vein type in Lower Paleozoic Shuangqiaozi Formation carbonaceous slate, the distribution of the orebodies is controlled by NE-trending ductile shear zones and faults. We have distinguished three paragenetic stages, i.e., early quartz stage, followed by quartz-pyrite stage and quartz-carbonate stage, with gold being introduced mainly in the second stage. The ore-forming fluids of the Wudaogou deposit are characterized by moderate-low temperature, low salinity, belonging to an H2O-NaCl-CO2 system. The δ18$\mathrm{O}_{\mathrm{H}_{2} \mathrm{O}}$and δ$\mathrm{D}_{\mathrm{H}_{2} \mathrm{O}}$ values for the gold-bearing quartz indicate that the ore-forming fluids were a mixture of magmatic and meteoric waters. The trace elements of pyrite from gold-bearing ores show a characteristic of hydrothermal origin. And the δ34S values suggest a mixed source for sulfur, i.e., the deep-seated magmatic and sedimentary rocks. The206Pb/204Pb,207Pb/204Pb and 208Pb/204Pb values of gold-associated pyrite show a broad linear correlation with those of the local magmatic and country-rock, implying that lead and possibly gold relate to these sources. Whereas the lead isotope compositions of ores (especially the value of 207Pb/204Pb and 208Pb/204Pb) are higher than those of the Shuangqiaozi Formation slate and the diorite. This indicates that the lead may be a product of leaching of the hosted-carbonaceous slate, which suggests that the ore metals originated from the Shuangqiaozi Formation. Integrating the data obtained from this study on geology, fluid inclusions, and H-O-S-Pb isotope systematics, we suggest that the Wudaogou gold deposit is an orogenic gold deposit.

Key words: fluid inclusion, H-O-S-Pb isotope, ore genesis, orogenic gold deposit, Wudaogou gold deposit

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