Current Science

D. K. Sinha ¹, Shekhar Gupta ¹, K. Nautiyal ¹, V. R. Akhila ¹, V. K. Shrivastava ¹, A. K. Padhi ¹, M. B. Verma ¹

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Hyderabad 500 016, IN

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.

Keywords

Polymetallic, Mineralization, Serpentinized Peridotite, Singhbhum Shear Zone, Uranium.

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A. P. Kushwaha ¹, S. P. Upadhyay ², Kuldeep Nautiyal ¹, B. V. S. N. Raju ³, D. K. Sinha ⁴

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Jaipur 302 033, IN
2 Atomic Minerals Directorate for Exploration and Research, Jamshedpur 831 001, IN
3 Atomic Minerals Directorate for Exploration and Research, New Delhi 110 066, IN
4 Atomic Minerals Directorate for Exploration and Research, Hyderabad 500 083, IN

Abstract

Uraninite, brannerite and secondary uranium minerals have been identified by petrographical studies of the leucosome of migmatites from Karke area, Garhwa district, Jharkhand (Figure 1). Secondary uranium minerals show fine flaky nature, anomalous interference colours and medium to high density alpha tracks on CN film. The host of uranium minerals is lensoidal in nature and occurs within the melanosome part of migmatitic band in Chhotanagpur Granite Gneiss Complex (CGGC)1. The width of migmatite varies from ~10 m to ~100 m, especially in Karke area. The migmatitic bands are flanked by pink granitoide occurring as linear body along the northern periphery. These are partially granitized metasediments and are the part of migmatites. These migmatites are hosted in biotite granite gneiss country with general trend of N65°W to S65°E, in this part of CGGC (Figure 1). A total of nine lenses of radioactive leucosome have been traced within a zone of 1000 m × 30 m trending NW–SE (Figure 2). The radioelemental distribution in these rocks is given in Table 1.

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Santu Patra ¹, Jitu Gogoi ¹, U. P. Sharma ¹, Rahul Banerjee ¹, D. K. Sinha ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Shillong 793 019, IN
2 Atomic Minerals Directorate for Exploration and Research, Hyderabad 500 016, IN

Abstract

No Abstract.

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Vivekanand Kain ¹, D. K. Sinha ², Deependra Singh ³, C. K. Asnani ⁴

Affiliations
1 Materials Group, Bhabha Atomic Research Centre, Mumbai 400 085, India
2 Atomic Minerals Directorate for Exploration and Research, Begumpet 500 016, India
3 Indian Rare Earths Limited (India), Prabhadevi 400 028, India
4 Uranium Corporation of India Ltd, Jaduguda 832 102, India

Abstract

Atomic minerals include mainly minerals containing uranium, thorium, rare metals, viz. niobium, tantalum, lithium, beryllium, titanium, zirconium, and rare earth elements (REEs) containing uranium and thorium as well as beach sand minerals. In India, these minerals are specified in Part B of the First Schedule to the Mines and Minerals (Development and Regulation) Act, 1957, and a few of these minerals containing uranium, thorium, niobium, tantalum and beryllium are included in the list of ‘Prescribed Substances’ under the Atomic Energy Act, 1962. After independence, different units of the Department of Atomic Energy have been playing a key role in making India self-reliant in these minerals and their processing. In the front end, the Atomic Minerals Directorate for Exploration and Research shoulders the responsibility for survey, exploration, and augmentation of atomic mineral(s) resources. The Uranium Corporation of India Limited is responsible for mining and processing of uranium ores, while the Indian Rare Earths (India) Limited caters to the mining of monazite-rich beach sands for recovery and processing of thorium and REEs. These three units of the DAE are ably supported by the Materials Group of Bhabha Atomic Research Centre, Mumbai, for technology development for mineral beneficiation and processing to produce metals/alloys/compounds required to support the requirements for expanding the nuclear power programme of India.

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Santu Patra ¹, U. P. Sharma ², Kamlesh Kumar ³, D. K. Sinha ⁴

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Hyderabad 500 016, India, IN
2 Atomic Minerals Directorate for Exploration and Research, Nagpur 400 001, India, IN
3 House No. 171, Swami Colony, Phase 1, Akar Nagar, Katol Road, Nagpur 440 013, India, IN
4 Flat 511, Block Garnet (E), Rainbow Vista@Rock Garden, Moosapet, Hyderabad 500 018, India, IN

Abstract

Here we report anomalous uranium concentration in tourmaline-bearing leucogranite occurring at Nuranang, Tawang district, Arunachal Pradesh, North East India. The leucogranite occurs as concordant layers parallel to gneissic foliation, similar to the gneisses of the Palaeopro­terozoic Se La Group. It is medium to coarse-grained, and is composed of quartz, potash feldspar and plagioclase as dominant minerals with variable proportions of muscovite, biotite, tourmaline and garnet. Apatite, zircon and pyrite are accessory minerals. Geochemically, the leucogranite is alkali-rich, peraluminous and highly differentiated. It is emplaced in a syn to late orogenic collision tectonic setting. Analyses of 10 granite samples collected at 500 m intervals show relatively high radioelemental concentration (U: 5–96 ppm, Th: 5–23 ppm, K: 2.23–7.72% and Th/U; 0.07–1.00, n = 10) compared to normal granite. Anomalous uranium concentration in the leucogranite is observed in a 200 m ´ 50 m area at Nuranang. Samples from this area have assayed 0.016–0.029% U3O8 and <0.005% ThO2. Leachable U3O8 content determined in five samples varies from 81.25% to 87.50%. Preliminary studies indicate that uranium is in the adsorbed state associated with iron oxide and alte­red feldspar/clay. The findings of anomalous uranium concentration in tourmaline-bearing leucogranite likely open up a new target area for uranium search in the Higher Himalaya of Arunachal Pradesh

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