Proterozoic Iron Oxide (Cu-Ni-U-REE) Type Mineralisation in the Environs of Dalma Volcanics, West Singhbhum District, Bihar. A New Horizon for Exploration of Polymetallic Ores

Significant uranium geochemical anomalies associated with Cu, Ni, REE, Au indicative of favourable Iron oxide breccia type of mineralisation has been located along a sympathetic faulted zone close to the main fault along the northern contact of Dalma volcanic range. The assemblages of the rocks found north of Dalma volcanics viz., carbon phyllite, carbonaceous quartzite, calc-arenite and cherty quartzite are indicative of typical marine environment of lower to middle Proterozoic age traceable for about 10 km over a 3-7 km wide zone. The mineralisation represented by iron oxide breccia is confined to a major structural zone parallel to a regional strike fault and is cut across by transverse faults. Significant anomalous concentration of U₃O₈ (140-770 ppm), Cu (173-498 ppm), Ni (148-1566 ppm), Au (<0.25 to 1.6 ppm), Ag (1.2 to 4.29 ppm) and REE (Y 131 to 607 ppm, La <50 to 993 ppm, Ce 41 to 91 ppm) points to its economic potentiality. The geological characteristics and tectonic set-up are akin to the major iron oxide (Fe-Cu-Ni/U-REE-Au) type of deposits reported elsewhere in the world. Investigation on the economic potentiality of the mineralisation is under progress.