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I. Bhattacharjee ¹, M. Agarwal ¹, O. P. Yadav ¹, M. K. Roy ¹, V. P. Saxena ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Nagpur - 440 001, IN
2 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Hyderabad - 500 016, IN

Abstract

The paper reports for the first time uranium mineralisation associated with phosphatic tuffaceous shale of the Lower Vindhyan Semri Group, near the southern margin of Son Valley around Mankisar-Karaundiya-Kathar area. Grab samples from this rock unit analyzed upto 900 ppm of U₃O₈ and upto 18.5 % of P₂O₅. Uranium enrichment in tuffaceous shale has been inferred due to hydrothermal activity.

Keywords

Uranium Mineralization, Semri Group, Sidhi District, Madhya Pradesh.

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V. P. Saxena ¹, R. M. Sinha ¹, O. R. Yadav ¹, R. V. S. Sesha Rao ²

Affiliations
1 AMD Complex, Begumpet, Hyderabad - 500 016, IN
2 AMD Complex, Civil Lines, Nagpur - 440 001, IN

Abstract

Signatures of concealed Unconformity-Related uranium mineralization at the contact of Chhotanagpur Granite Gneissic Complex [CGGCJ/Mahakoshal and Lower Vindhyan Semri sequence have come to light at Baskati, in Vindhyan- Mahakoshal Basin, following a multipronged exploration strategy. Systematic lithogeochemical sampling brought out uranium halos and most significant signals with concentration sufficiently above the normal background closely associated with breccias along reactivated faults and fractures occurring parallel and also oblique to the unconformity contact extending for a strike length of 17 km. Alteration halos and signatures like hematitisation, chloritisation and ilhtisation characterize the vicinity of these reactivated faults and fractures Geochemical study indicates a hypogene source for mineralizing fluids supported by geology, structure and lithogeochemistry and an 'Unconformity-Related uranium mineralization model' has been envisaged with the target area narrowed down for subsurface exploration.

Keywords

Geochemical Modelling. Uranium Mineralization, Unconformity, Alteration Halos, Baskati Area, Madhya Pradesh.

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A. V. Jeyagopal ¹, R. V. Singh ¹, P. Nageswara Rao ¹, V. P. Saxena ¹, R. M. Sinha ¹

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad - 500 0 16, IN

Abstract

Recent geological studies have brought out the presence of hitherto unknown Cumbum shale/Phyllite in the Julakallu-Pinneli area, Guntur district, Andhra Pradesh within the Palnad Sub-Basin of the Cuddapah basin. Cumbum shale/Phyllite and quarzite was found to rest above the Narji Limestone at southeast of Petasannigandla. This has necessitated northward shift of thrust boundary separating the Cumbum Formation and Narji Limestone from earlier known location. Subsurface data have confirmed larger thickness of the Narji Limestone than that reported in the literature. Geochemical characteristics of the Cumbum shale/Phyllite have indicated its deposition as first cycle of sediments in a tectonically active setting. This is supported by the depletion of immobile oxide Al₂O₃ and enrichment of mobile oxide CaO in the Cumbum shale. The A-CN-K plot indicates that provenance for shale/Phyllite could be granodiorite to granite in composition, which is also supported by petrological observations. The field, petrological and geochemical interpretations have brought out much new information on this part of the basin, which necessitates, revision of the geology of area.

Keywords

Cumbum Formation, Narji Limestone, Thrust Boundary, Cuddapah Basin, Julakallu, Andhra Pradesh.

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P. Nageswara Rao ¹, Anjan Som ¹, T. Perumal ¹, P. B. Maithani ¹, V. P. Saxena ¹, R. M. Sinha ¹

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad - 500 016, IN

Abstract

Recent investigations have brought out significant uranium occurrences (up to 0 65% U₃0₈)spread over as discontinuous zones (up to 300 m × 280 m × 1-3 m) over an area of about 7 km × 2 km along the northern part of Palnadu Sub-Basin. The radioactive zones are exposed along the Upper Proterozoic unconformity contact between the basement granite and the Banganapalle quartzite near Lavur Tanda, Jaitram Tanda, Boligutta Tanda, Rallavagu Tanda and Gandhi Nagar villages in Nalgonda district, Andhra Pradesh. These findings are reported in this note along with some features of mineralisation.

Keywords

Uranium Occurrence, Proterozoic, Palnadu Sub-Basin, Andhra Pradesh.

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O. P. Yadav ¹, P. K. Panchal ¹, T. S. Miglani ¹, V. P. Saxena ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Jaipur - 303 906,, IN
2 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Hyderabad - 500 016, IN

Abstract

No Abstract.

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M. B. Verma ¹, M. K. Roy ², V. P. Saxena ³

Affiliations
1 Atomic Minerals Directorate For Exploration and Research, Department of Atomic Energy, Hyderabad - 500016, IN
2 Atomic Minerals Directorate For Exploration and Research, Department of Atomic Energy, Jaipur - 302018, IN
3 Atomic Minerals Directorate For Exploration and Research, Department of Atomic Energy, Nagpur - 440 001, IN

Abstract

Thmly laminated, pelagic, Banded Iron Formation (BIF) of Lower Proterozoic Aravalli Supergroup lies close to basement granite and phyllites over a stretch of 5 km along the Udaisagar-Kalamagra tract, Udaipur district, Rajasthan. BIF is characterised by rhythmic stratification of meso- and micro-bands of iron oxides with light coloured bands of silica/chert. Banded Haematite Quartzite (BHQ), a part of BIF, is 5-30 m in width and is intercalated with carbonaceous shale/phyllites. Primary sedimentary structures, viz., bedding, banding, laminations, convolute lammations and synsedimentary breccia and faults, coupled with low value for Co/Ni (0.18; n = 7) suggest its deposition as chemogenic sediment in a calm, tranquil and deep-sea environment.

BIF analysed on an average (n=5) 35.81 % Fe₂O₃ and 34.5% Si0₂ with enrichment in sulphides and uranium (138 ppm). Correlation matrix shows strong positive correlation between uranium and copper (r = 0.80) and negative correlation of U with V, Ni, Co and Mo. Uranium content varies from 100 to 470 ppm (n = 37) and appears to be in adsorbed state on ferric oxide. Field relationship, coupled with ternary plots of Al₂O₃ - (CaO + MgO) - SiO₂, Fe₂O₃ - (CaO+MgO) - SiO₂ and Eu/Sm ratio (av. 0.275; n = 10) confirms its Proterozoic age. BIF exposed at Udaisagar-Kalamagra tract forms a linear belt and resembles the early Proterozoic Lake Superior type in its geochemical signatures.

Keywords

Geochemistry, BIF, Uranium, Base Metal Sulphides, Aravalli Supergroup, Udaisagar, Rajasthan.

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K. S. Mishra ¹, P. Jagadeesan ¹, K. K. Pandey ¹, V. P. Saxena ², R. M. Sinha ²

Affiliations
1 AMD, CR, Nagpur - 440 001, IN
2 AMD, Hyderabad-500 016, IN

Abstract

Rare earth element (REE) geochemistry of uranium bearing columbite-tantalite and multiple Nb-Ta oxide phases from the Pandikimal-Jangapara pegmatites, Jharsuguda district, Orissa have been studied and evaluated columbite-tantalite from these areas contain low ∑REE (100-1000 ppm) with LREE/HREE_CN<0.5 and minor amounts of uranium (0.3-0.6 % U₃O₈). Multiple oxide phases (yttrotantalite, samarskite, microlite and fergusonite) contain elevated amounts of U (10-11 % U₃O₈) and REE (19-28 %) with HREE>LREE. Plot of ∑REE vs. Chondrite-Normalised LREE/HREE shows positive correlation in 'U' rich multiple oxides compared to those from columbite tantalites which tend to show a negative correlation. The LREE/HREE ratio is 0.24 with negative Eu anomaly (Eu/Eu = 0.1) indicating evolved nature of these pegmatites.

Keywords

Rare Earth Element (REE), Columbite-Tantalite, U-Bearmg Multiple Oxide Phases, Pandikimal, Orissa.

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B. Venkateswaran ¹, I. H, Israili ¹, O. P. Yadav ¹, V. P. Saxena ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Nagpur- 440 001, IN
2 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Hyderabad - 500 0 16, IN

Abstract

Significant uranium mineralisation associated with subfeldspathic arenite of Lower Denwa Formation (Mid Triassic) has been located at Kharatoria, dist Chhindwara, M P in Satpura Gondwana Basin. Grab samples collected from the radioactive horizon analysed up to 0 1%U₃O₈, with <0 005%ThO_2. Besides, a spring sediment sample collected from the same locality indicated anomalous concentration of U, Zn, Pb and Ce and Th. Preliminary studies revealed the possibility of sedimentary facies/Hydrothermal control of uranium mineralisation and probable presence of organic/Inorganic carbon induced reducing environment in the area.

Keywords

Uranium, Upper Gondwana, Genetic Controls, Kharatoria, Chhindwara District, Madhya Pradesh.

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