• Physico-chemical conditions of ore deposition in Malanjkhand copper sulphide deposit

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      https://www.ias.ac.in/article/fulltext/jess/095/02/0209-0221

    • Keywords

       

      Fluid inclusion; homogenization; boiling; fugacity

    • Abstract

       

      Heating and freezing studies on fluid inclusions in quartz from mineralized quartzfeldspar reef reveal the presence of type A CO2-H2O (H2O>50% by volume), type B CO2-H2O (H2O<50% by volume), type C pure CO2 and type D pure aqueous inclusions. Types A, B and C are primary and/or psuedo-secondary inclusions while type D are secondary. Types A and B homogenize on heating into different phases at similar temperatures ranging between 307 and 476°C, indicating entrapment from boiling hydrothermal solutions. Type D inclusions homogenize into a liquid phase at temperatures between 88 and 196°C. Boiling of hydrothermal solutions led to the formation of a CO2-rich phase of low density and salinity that coexisted with another dense and saline aqueous phase with very little CO2 dissolved in it. Ore and gangue mineral assemblage of primary ores indicate that ore deposition was characterized by logfO2=−34.4 to −30.2 atm, logfS2=−11.6 to −8.8 atm and pH=4.5 to 6.5.

    • Author Affiliations

       

      S Jaireth1 M Sharma1

      1. Department of Earth Sciences, University of Roorkee, Roorkee - 247 667, India
    • Dates

       
  • Journal of Earth System Science | News

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