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Trimodal distribution of CO2-bearing fluid inclusions in the gold — silver-bearing quartz veins of the Phuoc Thanh area, Central Vietnam: Its implication to the Au−Ag precipitation

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Abstract

CO2-rich fluid inclusions from quartz veins provide information about pressure-temperature conditions, as well as effervescence, in the gold-silver-bearing quartz veins in the Phuoc Thanh area, Central Vietnam. Homogenization temperatures of fluid inclusion are bimodal, and support textural evidence that mineralization occurred in two stages. 90% of the fluid inclusions in the quartz are CO2-bearing. The trimodal distribution of CO2 mole fraction of the inclusions are common in the area, which indicates the CO2 unmixing, resulting the separation of the high (type IIb) and low (type IIa1) XCO2 fluids from the parental fluid (type IIa2) with intermediate XCO2. The precipitation of associated sulfide and Au−Ag minerals is related to CO2 effervescence with a concomitant decrease in sulfur activity. The temperature of mineralization is estimated as the range from 300 to 380°C in stage I and from 230 to 300°C in stage II. Pressure of ore formation ranged from 350 to 500 bars during both stages.

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References

  • Barnes, H.L., 1979, Solubilities of ore minerals. In: Barnes, H.L. (ed.), Geochemistry of Hydrothermal Ore Deposits. Wiley, New York, p. 404–460.

    Google Scholar 

  • Benning, L.G. and Seward, T.M., 1996, Hydrosulphide complexing of Au(I) in hydrothermal solutions from 150–400 and 500–1500 bar. Geochimica et Cosmochimica Acta, 60, 1849–1871.

    Article  Google Scholar 

  • Bowers, T.S. and Helgeson, H.C., 1983, Calculation of the thermodynamic and geochemical consequences of nonideal mixing in the system H2O−CO2−NaCl on phase relations in geologic systems: Equation of state for H2O−CO2−NaCl fluids at high pressures and temperatures. Geochimica et Cosmochimica Acta, 47, 1247–1275.

    Article  Google Scholar 

  • Burruss, R.C., 1981, Analysis of phase equilibria in C−O−H fluid inclusions. In: Hollister, L.S. and Crawford, M.L. (eds.), Short Course in Fluid Inclusions: Applications to Petrology. Mineral Association of Canada, Toronto, p. 39–74.

    Google Scholar 

  • Collins, P.L.F., 1979, Gas Hydrates in CO2-Bearing Inclusions and the Use of Freezing Data for Estimation of Salinity. Economic Geology, 74, 1435–1444.

    Google Scholar 

  • Diamond, L.W., 1994, Introduction to phase relations of CO2−H2O fluid inclusions. In: De Vivo, B. and Frezzotti, M.L. (eds.), Fluid Inclusions in Minerals: Method and Application. Virginia Polytechnic Institute & State University, Blacksburg, p. 131–158.

    Google Scholar 

  • Hayashi, K.-I. and Ohmoto, H., 1991, Solubility of gold in NaCl- and H2S-bearing aqueous solutions at 250–350. Geochimica et Cosmochimica Acta, 55, 2211–2126.

    Google Scholar 

  • Kim, S.-Y. and Chi, S.-J., 2001, Pluid inclusion and stable isotope studies of gold deposits in the Ganboke mineralized district, Pala area, Chad. Geosciences Journal, 5, 27–45.

    Article  Google Scholar 

  • KORES (Korea Resources Corporation), 1999, Report on the joint geological and mineral exploration in Phuocson district, Quang Nam Province, the Socialist Republic of Vietnam. KORES and the Department of Geology and Minerals of Vietnam, Seoul, 289 p.

    Google Scholar 

  • Potter, R.W. III, Clynne, M.A. and Brown, D.L., 1978, Freezing point depression of aqueous sodium chloride solutions. Economic Geology, 73, 284–285.

    Google Scholar 

  • Seward, T.M., 1984, The transport and deposition of gold in hydrothermal systems. In: Forster, R.P. (ed.), Gold 82. A. A. Balkema, Rotterdam, p. 165–181.

    Google Scholar 

  • Seward, T.M., 1989, The hydrothermal chemistry of gold and its implications for ore formation: Boiling and conductive cooling as examples. Economic Geology, Monograph 6, 398–404.

    Google Scholar 

  • Seward, T.M. and Barnes, H.L., 1997, Metal transport by hydrothermal ore fluids. In: Barnes, H.L. (ed.), Geochemistry of Hydrothermal Ore Deposits. John Wiley & Sons, Inc., New York, p. 435–486.

    Google Scholar 

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Correspondence to Insung Lee.

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Lee, I., Shin, D. Trimodal distribution of CO2-bearing fluid inclusions in the gold — silver-bearing quartz veins of the Phuoc Thanh area, Central Vietnam: Its implication to the Au−Ag precipitation. Geosci J 7, 21–26 (2003). https://doi.org/10.1007/BF02910261

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  • DOI: https://doi.org/10.1007/BF02910261

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