Serpentinized peridotite-hosted uranium mineralization (U-Cr-Ni-Mo-REE-Fe-Mg) in Kudada-Turamdih area: A new environment of Metallogeny in Singhbhum shear zone, India

Abstract

Recent exploration efforts in Kudada-Turamdih area has brought to light, for the first time, serpentinizedperidotite- hosted uranium mineralization (up to 0.188% U3O8) of polymetallic nature (U-Cr-Ni-Mo- REE-Fe-Mg) in the domain of Singhbhum Shear Zone (SSZ). The peridotite has been emplaced into the Iron Ore Group (IOG) and represents late phase activity in the IOG. Exploratory drilling has established substantial lateral (600 m) and downdip (1000 m) continuity of the mineralization. Subhedral to anhedral disseminated uraninite grains (10-600 μm) with cell dimensions of 5.4498 to 5.4650 Å suggest crystallization in meso to hypo-thermal range (300- 500°C). Magnetite, chromite, molybdenite, cobaltite, nickeline, vaesite, cerussite, pyrite and chalcopyrite have also been identified in the REE enriched (Av. 1457 ppm) uraniferous peridotite. Presence of MgO (18-28%), Cr (295-3165 ppm), Ni (222-9530 ppm), Au (11-30 ppb), Pt (47-95 ppb) and As (15-755 ppm) suggests komatiitic parentage of host rock. Discovery of polymetallic mineralization in serpentinized peridotite, a hitherto unknown geological environment, opens up scope for further research and enhancement of uranium resources in the SSZ.