PETROGRAPHY AND MINERALOGY OF MINERALIZED HOST ROCKS FROM THE BHITARDARI GOLD PROSPECT, SINGHBHUM CRUSTAL PROVINCE, EASTERN INDIA

Abstract

Gold is very precious and economically important mineral. There are several types of gold deposits present in the world. Some are paleoplacer, Iron-Oxide Copper Gold deposits, Orogenic gold deposit etc. India consist of four Archean cratons, Dharwar, Aravali-Bundelkhand, Singhbhum and Bastar craton. The Singhbhum craton is in eastern India covers an area of 40,000 Km2. Eastern Indian shield is made up of three domains , Singhbhum Craton, North Singhbhum Mobile Belt and Chotanagpur Granite Gneiss. Gold occurrences in Singhbhum crustal province are restricted to greenstone belts of Paleo-Mesoarchean age within Archean core region and the North Singhbhum Mobile Belt (NSMB) of paleo to Mesoproterozoic age. In cratonic part gold mineralisation has taken place as orogenic gold deposit or as paleo-placer gold . In the North Singhbhum Mobile Belt mineralization has taken place along reef of quartz and sulfides which are hosted in metamorphosed rocks in which facies of metamorphism varies from greenschist to amphibolite. Present study is in the Bhitardari area in the Singhbhum Crustal Province. An investigation in the area suggest the presence of gold. Rock types present in the area are schist-actinolite schist, mica schist, phyllite. Petrography indicate the presence of sulfides and shearing in the area. Chalcopyrite, pyrite, galena are major sulfides and gold is in association of chalcopyrite in chlorite schist rock type. Shear sense indicators are garnet and quartz porphyroclast and down dip lineation, SEM analysis indicate presence of low-Ti iron oxide, garnet, monazite and rutile. EPMA confirms the presence of sulfides. All studies suggest that Bhitardari is part of Singhbhum Shear Zone as several sense indicators are found in the area and down dip lineation is characteristic of SSZ which is also present in the area.The presence of iron oxides, chalcopyrite, pyrite, galena and gold are typical mineral assemblage of IOCG type deposit.Co and Ni plot of pyrite gives the knowledge of fluid.It suggest that fluid is hydrothermal-magmatic. Presence of sulfides, gold, iron oxide and brittle ductile indicators conclude that Bhitardari is part of SSZ and mineralization is of IOCG type.