Titaniferous Magnetite Deposits Associated with Archean Greenstone Belt in the East Indian Sheild

Abstract

In the East Indian Shield, occurrence of titaniferous magnetite deposits associated with the Archean Greenstone belt occur in Kumhardubi, Betjharan and Nuasahi areas of Odisha and Dublabera area of Jharkhand. The ore bodies comprise lenses, veins, bands and patches within gabbroic rocks. Petrogenetic studies have revealed the primary and secondary mineral constituents of the ores such as titanomagnetite, ilmenite, hematite, spinel, cobaltite, goethite, martite, rutile and silicate gangue minerals. Various crystallographic intergrowths are resulted from exsolution & oxidation at different temperatures during cooling of the sub-solidus magma. Chemical analyses show that the ore contains 10.35-17.68 wt.% TiO2, 0.148-0.227 wt.% V2O3 and 32.75-67.39 wt.% Fe2O3. Different geochemical composition diagrams confirm their tholeiitic origin. The formation of the massive ore bodies is referred to late magmatic crystallization from tholeiitic magma followed by Fe-Ti enriched residual liquid injection within the host rocks. Syn to late formation of the magnetite ores along with gabbro-anorthositic intrusive with respect to the Archean Greenstone Belt of East Indian Shield is suggested.