Primary Ore Mineral Assemblage And Fluid Inclusion Studies of The Cu-Ag

The study area exposes low grade, high tonnage copper – silver mineralisation, hosted within quartz- biotite-amphibole schist with intercalatory marble bands enveloped within poorly mineralised metapelites, belonging to the carbonate – metapelite assemblage of the Meso-Proterozoic Ajabgarh Group of Delhi Supergroup. Bornite – chalcopyrite- chalcocite- subordinate covellite are the dominant copper bearing minerals and occur within the remobilized quartz ± carbonate veins /veinlets pervading the host rocks. Coarse disseminations of bornite ± chalcopyrite occur both within the scapolite bearing calc silicates of the carbonate suite and scapolite bearing spotted schists of the metapelitic suite. Native Silver, Native bismuth and Silver- bismuth bearing phases, in the remobilized quartz- carbonate veins/veinlets, also occur in association with the major copper bearing phases. Significant ore textures as a) myrmekitic intergrowths of bornite-chalcocite, b) chalcocite lamellae in bornite (Fig1), c) bornite showing streaks of chalcopyrite as exsolved phases (Fig 2), implies a magmatic- hydrothermal condition of formation, the myrmekite being a product of “eutectic ” intergrowth (Ramdohr, 1969). Figure 1. Chalcocite lamettae in Bornite Figure 2. Bornite showing streaks of exsolved chalcopyrite. Development of coarse biotite books and aggregates of tourmaline (schorlitic) in the calc silicates in proximity to the mineralized zone, defines a wall rock alteration phenomena