Informatics Publishing Limited

Minati Roy ¹, A. K. Roy ², P. S. Parihar ³

Affiliations
1 AMD, Department of Atomic Energy, Northern Region, New Delhi-110066, IN
2 AMD, Department of Atomic Energy, F-1149, Chittaranjan Park, New Delhi (Ex AMD, NR, New Delhi), IN
3 AMD, Department of Atomic Energy, Head Quarter, Hyderabad-500016, IN

Abstract

Radioactive carbonaceous matter, possibly of organic origin, with coffinite inclusions {U(SiO₄)_{1_x}(OH)_4x} are reported for the first time in the fractures within the core samples of highly deformed Bundelkhand granitoids in the Gwalior Basin. Intense hydrothermal alterations along these fractures are manifested in the form of silicification, argillic alteration (clay formation), chlontisation, ferruginisation and by sulphide formation. The globular radioactive carbonaceous matter is of organic origin and generally associated with silica rich veins. Globular nature of this carbonaceous matter indicates their formation from coagulation of smaller colloids in a low temperature hydrotherm. Mixing of descending oxidizing hydrotherm derived from basinal fluid rich in heavy metals, uranium, organic matter and ascending reducing fluid (hydrotherm) rich in H₂S and Si in these fracture zones has resulted in the precipitation of sulphides, secondary quartz, carbonaceous material and coffinite.

Keywords

Radioactive Material, Bundelkhand Granite, Gwalior Basin, Madhya Pradesh.

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Rajeev Bidwai ¹, S. Srinivasan ¹, L. K. Nanda ¹, Atanu Banerjee ¹, P. N. Bangroo ¹, A. K. Rai ², P. S. Parihar ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Western Region, Jaipur 302 030, IN
2 Atomic Minerals Directorate for Exploration and Research, Hyderabad 500 016, IN

Abstract

No Abstract.

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Rajeev Bidwai , S. Srinivasan , L. K. Nanda , Atanu Banerjee , P. N. Bangroo , A. K. Rai , P. S. Parihar

Abstract

No Abstract.

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A. Yugandhara Rao ¹, K. Vijay Raj ², O. P. Yadav ², L. K. Nanda ³, A. K. Rai ³, P. S. Parihar ³

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Vishakapatnam 530 007, IN
2 Atomic Minerals Directorate for Exploration and Research, Jaipur 302 033, IN
3 Atomic Minerals Directorate for Exploration and Research, Hyderabad 500 016, IN

Abstract

Magnesium-bearing calcretes of soft-gritty and hard pan varieties containing uranium concentrations from 16 to 74 ppm with <10 ppm of thorium are located along the Saraswati palaeochannel at Khemasar village, Churu district, Rajasthan. The uraniumbearing calcretes are exposed over an areal extent of 300 m × 200 m with thickness of up to 2 m in an interdunal depression. The silty sand layer occurring below the calcrete horizon suggests that it is a valley-fill calcrete, deposited along a palaeochannel. This occurrence of uraniferous Mg-calcrete in the Saraswati river palaeochannel opens up a large area for uranium exploration in the calcrete environment of Thar Desert. These calcretes are composed of 15.94% to 25.39% CaO, 7.15% to 22.39% MgO and Sr/Ba ratio up to 66.98. There is a positive correlation of U with Sr/Ba and MgO. The high Sr/Ba ratio and MgO indicate water of saline nature and high rate of evaporation. Ephemeral centripetal drainage mixing with the dissected palaeochannel waters and groundwaters, under arid climatic conditions might have resulted in the formation of this kind of uranium-bearing calcrete in fluvio-lacustrine environment.

Keywords

Fluvio-Lacustrine Environment, Khemasar, Magnesian Calcrete, Surficial Type Uranium.

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Niroj K. Panda ¹, A. Yugandhara Rao ¹, K. Ramesh Kumar ², R. Mohanty ², P. S. Parihar ²

Affiliations
1 BSOI Group, 39-3-23/5 to 9, BVR mansions, Near Masjid Bus Stop, Murali Nagar, Visakhapatnam 530 007, IN
2 AMD Complex, Begumpet, Hyderabad 500 016, IN

Abstract

No Abstract.

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K. K. Sinha ¹, Pradeep Pandey ¹, C. L. Bhairam ¹, P. S. Parihar ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, West Block VII, R.K. Puram, New Delhi - 110 067, IN
2 Atomic Minerals Directorate for Exploration and Research, AMD Complex, 1-10-153/156, Begumpet, Hyderabad - 500 016, IN

Abstract

In the western part of Bundelkhand massif, a caldera with intra-caldera sediments, known as Dhala Formation, occurs as an outlier in and around Mohar village of Shivpuri district, Madhya Pradesh. For the first time, occurrence of peperite is being reported from the basal part of the Dhala sediment. Two types of peperites have been recognized: blocky and fluidal or globular with variable morphology. In peperitic zones, features like soft sediment deformations, presence of sediment into the rhyolite along cracks, vesiculation of the sediments and other evidences suggestive of sediment fluidization are some definite characteristics of interaction of hot magma with wet sediments forming peperite. The occurrence of peperites reflects the contemporaniety of deposition of the Dhala sediments and volcanism, which is well in accordance to the volcanic origin of Dhala structure. Further, the nature of unconformity between the Dhala and overlying Kaimur which is characterized by merely a few centimeter thick pebbly/conglomeratic bed does not appear to represent a large hiatus as expected between the Semri and Kaimur of Vindhyan Supergroup. So, the contemporaniety of the Dhala Formation (at least the lower part) as reflected by occurrence of peperites, coupled with the available age of the rhyolite and the nature of the unconformity between the Dhala and overlying Kaimur provide convincing evidence to correlate the Dhala Formation with the Lower part of the Kaimur and unlikely with the Semri Group or Bijawar as proposed earlier.

Keywords

Caldera, Peperites, Dhala Sediment, Bundelkhand, Vindhyans, Madhya Pradesh.

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Kalyan Chakrabarti ¹, N. R. R. Ecka ¹, B. Mishra ¹, P. V. Ramesh Babu ², P. S. Parihar ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Jamshedpur - 831 002, IN
2 Atomic Minerals Directorate for Exploration and Research, Hyderabad - 500 016, IN

Abstract

Ground Radiometric survey of Paleoproterozoic pyritiferous quartz-pebble conglomerate (QPC) occurring to the north of Pallahara area led to the discovery of a QPC type uranium mineralisation near Mankarhachua village. Significant radioactivity is recorded in three sub-parallel uraniferous QPC horizons with metamorphosed pebbly to medium grained recrystallised massive sandstones. Detrital grains of uranothorite, thorite, radioactive allanite, monazite, zircon, minute uraninite grains in carbonaceous matter and thucolite contributes to the radioactive phases present in QPC matrix. Adsorbed U on limonite and goethite, secondary uranyl minerals in matrix, along bedding planes and fractures are commonly observed. This discovery has opened up a new horizon for future exploration for QPC type uranium mineralization in the area. The paper presents observations on geology, radioactivity, petrological and geochemical nature of the uraniferous QPC horizons.

Keywords

Conglomerate, Uranium Mineralization, Orissa.

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K. Mahendra Kumar ¹, Madhuparna Roy ², G. Behra ², P. S. Parihar ², R. K. Gupta ³, Jamger Singh ³

Affiliations
1 Atomic Minerals Directorate for Exploration and Research Shillong 793011, IN
2 Atomic Minerals Directorate for Exploration and Research New Delhi 10066, IN
3 Atomic Minerals Directorate for Exploration and Research Hyderabad 500016, IN

Abstract

Pegmatitic injections within the magnetite bearing granitoid host rare metal and rare earth mineralisation at Jaurahi, Sonbhadra district, Uttar Pradesh. The ore minerals identified are columbite, eschynite, samarskite, fergusonite, monazite, thorite, uranothorite and zircon in association with magnetite, ilmenite and rutile. Samples of mineralised pegmatite have analysed 0.65 to 4.42% Nb and 0.55 to 4.85% Y.

Keywords

Economic Geology, Pegmatite, Columbite, Granitoid, Chhotanagpur Gneissic Complex, Sonbhadra, Uttar Pradesh.

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G. S. Yadav ¹, U. K. Pandey ², S. L. Aravind ³, P. K. Panchal ³, A. S. Venkatesh ⁴, P. R. Sahoo ⁴, A. K. Chaturvedi ², A. K. Rai ², P. S. Parihar ²

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Jamshedpur 831 002, IN
2 Atomic Minerals Directorate for Exploration and Research, Hyderabad 500 016, IN
3 Atomic Minerals Directorate for Exploration and Research, Jaipur 302 030, IN
4 Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad 826 004, IN

Abstract

Uranium mineralization in Bichun area, Jaipur district, Rajasthan, India is hosted by albitites within the Banded Gneissic Complex (BGC). Detailed mineralogical and EPMA studies reveal the presence of davidite along with brannerite and uraninite. The U-Pb concordia upper intercept age of 933 ± 13 Ma and Pb-Pb isochron age of 930 ± 4 Ma, on pure davidite fractions indicate the timing of uranium mineralizing event to be ca. 930 Ma. The timing of uranium mineralization can be correlated with the Grenvillian orogeny (ca. 1000 Ma). The Sm-Nd model age (T_DM) of daviditeis varies from 1851 to 2200 Ma with ε_{Ndi(930 Ma)} ranging from -10.7 to -15.5 which shows that the Palaeoproterozoic rocks with crustal component (either within BGC or basement granite) are the source for uranium.

Keywords

Albitite Zone, Davidite, Geochronology, Orogeny, Uranium Mineralization.

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G. Nagendra Babu ¹, A. Latha ¹, P. S. Dandele ², M. B. Verma ¹, R. Mohanty ¹, P. S. Parihar ¹

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Begumpet, Hyderabad-500016, IN
2 Regional Centre for Exploration and Research, AMD, Civil Lines, Nagpur-440001, IN

Abstract

There is no record of igneous activity in Upper Proterozoic-Kurnool/Palnad sediments. However, Igneous activity was recorded by number of geoscientists in the Cuddapah Super group of rocks in the Cuddapah Basin. For the first time the authors report the occurrence of eruptive igneous activity in the northern part of Palnad Basin,an equivalent of Kurnool Group, South of Venkataramapuram, Nalgonda district, Telangana State. The Igneous activity has affected the basal unit of Banganapalle Formation. Basal conglomerate is polymitic in nature with clasts/cobbles/boulders of dolerite, granite, granodorite, BMQ, meta-quartzite, quartzite, shale and lime stone of Palnad Formation. The average composition of conglomerate matrix (n=7) is 1.75% Fe2O3, 8.07% FeO, 3.74% MgO%, 8.07% CaO and 38.8% SiO2 which corresponds to basic igneous activity.

Keywords

Cuddapah Basin, Palnad Formation, Igneous Activity, Venkataramapuram, Nalgonda District, Telangana State.

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A. Markandeyulu ¹, I. Patra ¹, B. V. S. N. Raju ¹, A. K. Chaturvedi ¹, P. S. Parihar ¹

Affiliations
1 Atomic Minerals Directorate for Exploration and Research, AMD Complex, Begumpet, Hyderabad – 500 629, IN

Abstract

The Paleo-Meso Proterozoic Gwalior basin (E - W), lying to NW fringe of Bundelkhand massif is represented by litho-package of lower arenaceous Par Formation and upper chemogenic Morar Formation. It is bounded by Indo- Gangetic alluvium in north and east, Kaimur sediments in west and Bundelkhand granitoids in south. Gwalior Basin has been the exploration target for uranium mineralization right from early 60's. Surface radioactivity anomalies due to uranium has been reported in both Par and Morar Formations of Gwalior Group and Vindhyan sediments. Besides presence of syngenetic uranium in the system, presence of post-depositional faults and fractures are the favorable factors. Aeromagnetic survey was carried out by AMD in 2002 with N-S lines of 500 m interval covering 9406 line km. The data with sampling interval of 0.1 sec was corrected for spikes, diurnal variation, IGRF, heading and lag. Final processed images are prepared after suitable leveling and gridding. First vertical derivative of TMI-RTP and tilt-angle derivative images are used to map the litho-contacts, lineaments and structural features. Numerous NE-SW trending low amplitude and NW-SE trending high amplitude magnetic linears corroborate with quartz reefs and basic dykes respectively. Besides, E-W to WNW-ESE and ENE-WSW trending fractures are also evident from the processed image maps. Further, the Euler's depth solution of gridded aeromagnetic data calculated for structural indices of 0 and 1 are very consistent in locating the position of the causative sources. Based on the amplitude and textural character of processed aeromagnetic data, alteration zone is delineated well within the Morar Formation. Enhanced Thematic Mapper (ETM+) image with 30m resolution was merged with IRS PAN 1D (5.8 m resolution) for better spatial/radiometric resolution to extract lithocontacts and lineament patterns. Merged PAN band-4 after linear contrast and edge enhancement techniques deciphered detailed lineament pattern, which corroborate the magnetic data. Merged ETM+ (RGB 751) and PC (PC1-PC2-PC5) images depict litho-logical contrast. Integration of aeromagnetic and satellite imagery data helped in understanding the structural fabric of the Gwalior Basin and to identify favorable loci of uranium mineralization.

Keywords

Gwalior Basin, Aeromagnetic Survey, Satellite Imagery, Structural Fabric.

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