Fluid inclusion studies on mineralized and unmineralized granites of Malanjkhand Cu deposit in Central India

Our study presents fluid inclusion data on the mineralized and unmineralized granites from the Malanjkhand Cu deposit, Central India.Inclusions are recognized in quartz, which are similar in mineralized as well as unmineralized zones.These are monophase aqueous, biphase aqueous and polyphase (L+V+H) inclusions.The microthermometry results imply relatively high temperature (170-381.4 0C) of fluid entrapment in the mineralized granites, compared to considerably lower (169-235.8 0C) in unmineralized counterparts.Although, the salinity of fluid appears to be similar in both the variants, ranging from 4.07-15.47wt% NaCl equivalent for mineralized granites and between 4.07 and 14.57 wt% NaCl equivalent for the unmineralized granites.The calculated salinity for mineralized granite (0.57-0.99 gm/cm 3 ) is found to be lower than the unmineralized granite (0.87-0.99 gm/cm 3 ).Textural and microthermometry results advocate that the hot brine fluid with lower density, generated from the mineralized granite silicic magma, was solely responsible for the ore deposition in mineralized veins and reefs, while cooler brine with high density fluid generated from unmineralized granite, was responsible for barren quartz veins.