Geothermic Control of Ore Assay in Mosaboni Mine, Singhbhum-Evidences from Fluid Inclusions

There exists a strong control of fluid inclusion homogenization temperature on the assay of copper ore in the Mosaboni mine. The ores, having copper assay greater than or equal to 1.5%,are more or less confined to a homogenization temperature range of 320° and 360°C. This also reflects that these ores were precipitated within narrow salinity limits of 38.6 and 42.8 equivalent wt. per cent NaCl. The homogenization temperature varied between 275° and 420°C with the highest recorded temperatures at the bottom levels indicating that the ore-forming fluids came from below and migrated upward precipitating various grades of ores at favourable sites under suitable physico-chemical conditions.