Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Mukherjee, Abhijeet

• Two New Kimberlites in Bommaganapalli Area, Anantapur District, Andhra Pradesh, Based on Systematic Stream Sediment Sampling and Ground Magnetic Survey

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Authors

Abhijeet Mukherjee ¹, Ch. Sravan Kumar ¹, K. Krishna Reddy ¹, S. N. Siddiquie ¹, Lokesh Chaturvedi ¹

Affiliations
1 National Mineral Development Corporation Ltd., Khanij Bhavan, Masab Tank, Hyderabad – 500028, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 69, No Spl Iss 3 (2007), Pagination: 625-640

Abstract

Two Kimberlite pipes in Bommaganapalli area, Kalyandurg, Anantapur District are reported based on stream sediment sampling yielding HIM's viz., garnets ('G 9' lherzolitic, 'G 10' harzburgitic and eclogitic with Na₂O (>0.07 wt%), Cr-diopsides (from garnet peridotites), spinels and ilmenites. Ground magnetic survey indicated magnetic anomaly of about 280 nT in KL-5 and an anomaly of100 n T over KL-6.The anomaly over KL-5 was dipolar. The 'Maturation Index' (MI) of 9.8 and MgO content 8.08 of the calcrete over this area indicate their kimberlitic nature. Analysis indicates that the chrome spinels fall in the diamond stability field. Garnets suggest they are of the nature of "G 10" harzburgitic garnets.

Keywords

Kimberlite, Stream Sediment Sampling, Magnetic Survey, Diamond Indicator Minerals.

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• Chemistry of Eclogitic Garnets from Bahradih Kimberlite, Raipur District, Madhya Pradesh

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Authors

Abhijeet Mukherjee ¹, Amitabh Tripathi ¹, Prakash K. Singh ¹, E. V. S. S. K. Babu ²

Affiliations
1 National Mineral Development Corporation Limited, Khanij Bhawan, Masab Tank, Hyderabad - 500 028, IN
2 Atomic Minerals Division, Begumpet, Hyderabad - 500 016, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 56, No 4 (2000), Pagination: 425-430

Abstract

Garnet concentrates from the Bahradih kimberlite pipe were analysed by electron microprobe and found to be mostly of the pyrope-almandine variety with significant amount of Na₂O and a pyrope content in the range of 48.76-61.45%, almandine 30.82-41.97% and grossular 2.313-9.983%, indicating eclogitic paragenesis. Their Mg# ranges from 53.92 to 66.59. The presence of traces of Na and Ti in these garnets indicates that substitution of these elements into the garnet structure is feasible at high pressure. Five out of 50 garnets analysed from Bahmdih show Na₂O = 0.07 wt.% which indicates that they are from the diamond stability field, as confirmed further by the recovery of diamonds from the pipe.

Keywords

Kimberlite, Garnet, Pyrope, Almandine, Diamond, Raipur District, Madhya Pradesh.

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• Sulfur Isotope Variations in Barite and Pyrite of Hydrothermal Barite Deposits of Cuddapah Basin, Andhra Pradesh

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Authors

Abhijeet Mukherjee ¹, Ashok Ballurkar ²

Affiliations
1 National Mineral Development Corporation Ltd., Masab Tank, Hyderabad-500 028, IN
2 Centre for Exploration Geophysics, Osmania University, Hyderabad-500007, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 47, No 4 (1996), Pagination: 425-430

Abstract

The δ³⁴S X-CDT values for barite and pyrite range from +23.6 to +25.5 per mil and -0.9 to +1.9 per mil respectively. Data of fluid inclusion studies enable temperature of deposition to be 250°C after pressure correction of homogenization temperatures (Th). The δ³⁴S X-CDT values of pyrite and barite suggest igneous source for pyrite and marine for barite implying that they are not formed together. The δ³⁴S X-CDT values of barite agree with δ³⁴S X-CDT values for contemporaneous Proterozoic sea water.

Keywords

Sulphur Isotopes, Barite, Pyrite, Cuddapah Basin, Andhra Pradesh.

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• Geothermometry and Oxygen Barometry of Coexisting Iron-Titanium Oxides of Majhgawan Diamondiferous Pipe, Madhya Pradesh

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Authors

Abhijeet Mukherjee ¹, K. S. Rao ¹, D. Bandyopadhyay ¹, Gautam Roy ², A. K. Chatterjee ³

Affiliations
1 National Mineral Development Corporation Ltd., Khanij Bhawan, Masab Tank, Hyderabad-500028, IN
2 Department of Applied Geochemistry, Osmania University, Hyderabad-500007, IN
3 302-Expresso Apts., Lakdikapool, Hyderabad-500004, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 49, No 1 (1997), Pagination: 55-60

Abstract

Geothermometry of the coexisting magnetite-ilmenite (Mt-Ilm) pair from Majhgawan diamondiferous pipe indicates a temperature of 1150°C. The values of fO₂ T and P fall in the equilibria field defined by iron-wustite (IW) and wustite magnetite (WM) indeating depth of sampling of about 155km and pressure of 46kbar.

Keywords

Geothermometry, Geobarometry, Fe-Ti-Oxides, Majhgawan Pipe.

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• Chemistry of Phlogopite Megacrysts in Majhgawan Diamondiferous Pipe, Panna, Madhya Pradesh

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Authors

Abhijeet Mukherjee ¹, K. S. Rao ¹, A. K. Chatterjee ²

Affiliations
1 National Mineral Development Corporation Limited, Khanij Bhawan, Castle Hills, Masab Tank, Hyderabad-500028, IN
2 302, Expresso Apts., Lakdika Pool, Hyderabad-500004, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 49, No 2 (1997), Pagination: 203-206

Abstract

The phlogopite megacrysts of Majhgawan diatreme have been grouped into two groups and from the inspection of the chemical analysis of micas their origin are discussed.

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• Fluid Inclusion Study of Vein and Bedded-Type Barite of Cuddapah Basin, Andhra Pradesh

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Authors

Abhijeet Mukherjee ¹, Ashok Ballurkar ²

Affiliations
1 National Mineral Development Corporation, Khanij Bhavan, Masab Tank, Hyderabad-500028, IN
2 Centre of Exploration Geophysics, Osmania University, Hyderabad-500007, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 50, No 5 (1997), Pagination: 587-592

Abstract

Fluid inclusion study is carried out on the vein and bedded-type barite of the Proterozoic Cuddapah basin of Andhra Pradesh. In the case of vein barite, primary inclusions are mostly monophase and liquid-rich biphase (L+ V), with their freezing temperatures indicating their composition as H₂O+NaCI±KCl and density of the ore forming fluids as 0.901 to 0.944 g/cm³. The primary liquid-rich biphase (L+V) inclusions of the hydrothermal vein barite shows homogenization temperatures in the range of 230° to 260°C. The primary inclusions of the bedded (volcanogenic) barite deposits of Mangampeta are monophase carbonic with densities corresponding to 0.76 to 0.88 g/cm³. A conceptual mobilization-deposition model for the vein-type barite mineralization is given.

Keywords

Fluid Inclusion, Barite, Geochemistry, Cuddapah Basin, Andhra Pradesh.

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• Chemistry of Garnet and Ilmenite from Majhgawan Diamondiferous Pipe, Panna District vis-a-vis Diamond Potential and Preservation

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Authors

Abhijeet Mukherjee ¹, K. S. Rao ¹, D. Bandyopadhyay ¹, Gautam Roy ²

Affiliations
1 National Mineral Development Corporation Ltd., Khanij Bhavan, Masab Tank, Hyderabad - 500 028, IN
2 Applied Geochemistry Department, Osmania University, Hyderabad - 500 007, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 50, No 4 (1997), Pagination: 441-448

Abstract

The compositional trends in ilmenites from Majhgawan indicates slightly increased values of -log f02 i.e., 9.2. The divariant plots of Fe₂O₃ vs MgO and Cr₂O₃ vs MgO indicate resorption of most diamonds. The rounded-dedecahendra from indicates a preservation percentage of 65-70. The wine-red garnets from diamondiferous pipe are moderately subcalcic. The CaO vs Cr₂O₃ plot shows that they fall very close to the 85 percent Gurney line indicating emplacement at the craton margin having moderate diamond content. Geothermobarometry based on the co-existing pyropeknorringite and spinel geothermobarometer for the diamondiferous pipe yielded an equilibration temperature and pressure of 1160°C and 47 KbaT.

Keywords

Economic Geology, Diamond. Geochemistry, Madhya Pradesh.

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• Fluid Inclusion Studies and Sulphur and Strontium Isotope Geochemistry of Vein Barites of Velugumetla, Khammam District, Andhra Pradesh

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Authors

Abhijeet Mukherjee ¹, G. Prabhakar ²

Affiliations
1 National Mineral Development Corporation Limited, Khanij Bhavan, Masab Tank, Hyderabad - 500 028, IN
2 Department of Geology, PG College of Science Saifabad, Osrnania University, Hyderabad - 500 004, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 68, No 2 (2006), Pagination: 201-206

Abstract

The Velugumetla barite deposit, Khammarn district is studied for fluid inclusions, sulphur and strontium isotopes The inclustons that are random in distnbution and varying in size from 15-30 μ are classed as primary and the inclusions le ss than 15 μ in size and having linear trails as secondary Heating runs of the primary and secondary inclusions show peaks at 235° C to 245 °C(T_h) and 130°C to 140°C respectively Both the primary and secondary biphase liquid rich(L+V) inclusions hornogenized by the disappearance of the vapour phase The composition of fluid has been surmised as H₂O+NaCl+KCl The salinity was calculated as 12 7 wt% NaCI eqv The minimun depth of precipitation of barite was estimated to be 300 m and the density calculated as 0 94g/cm³ with a fluid pressure of 31 2 bars The fluid inclusion data of barite veins of vein bantes of Velugumetla, Khammarn district and other vein deposits of the Cuddapah Basin are correlatabte in terms of composition, salinity, density, pressure depth of entrapment and temperature of homogenization.

The δ³⁴S values for barite varies between +23 5 to+25 6 %O and pyrite has values between -0 9 to + 1 9 %O in case of the barite pyrite pairs that were studied from six different localities of the Cuddapah Basin and Khammam The δ<sup34 S values of the vein barite deposits of the Cuddapah Basin and Khammam area similar to the contemporaneous sea water The strontium isotope (⁸⁷Sr/⁸⁶Sr)ratios) show wide variation 0 705 to 0 722 for the vein barites of Cuddapah Basin and Kharnmam and indicates significant contribution of radiogenic Sr from older continental crust.

Keywords

Fluid inclusions, sulphur Isotopes, Strontium Isotopes, Velugumetla, Khammam district, Cuddapah Basin, Andhra Pradesh.

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• Discovery of a New Kimberlite Pipe Using Multidisciplinary Approach at Kalyandurg, Anantapur District, Andhra Pradesh

Abstract Views :184  |  PDF Views:174

Authors

Ch. Sravan Kumar ¹, Abhijeet Mukherjee ¹, Rajesh K. Vishwakarma ¹

Affiliations
1 National Mineral Development Corporation Ltd., Investigation Division, Khanij Bhavan, Masab Tank, Hyderabad- 500028, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 64, No 6 (2004), Pagination: 813-817

Abstract

No Abstract.

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• Chemistry of Eclogitic Garnets from Bahradih Kimberlite, Raipur District, Madhya Pradesh

Abstract Views :184  |  PDF Views:154

Authors

Abhijeet Mukherjee , Amitabh Tripathi , Prakash K. Singh , E. V. S. S. K. Babu

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 57, No 2 (2001), Pagination: 189-189

Abstract

No Abstract.

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• Fluid Inclusions Associated with Gold Mineralization in Kunchiganahalu Banded Iron formation, Chitradurga Schist Belt, Karnataka: a Preliminary Appraisal

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Authors

Abhijeet Mukherjee ¹, Gautam Roy ², Amitabh Tripathi ¹

Affiliations
1 National Mineral Development Corporation Ltd., Khanij Bhawan, Masab Tank, Hyderabad - 500028, IN
2 Department of Applied Geochemistry, Osmania University, Hyderabad - 500007, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 58, No 6 (2001), Pagination: 533-537

Abstract

Three types of fluid inclusions i.e., Type I (C0₂-H₂O) primary inclusions, trail- bound Type II biphase (H₂O, L+V) inclusions and Type III monophase C0₂ inclusions associated within intra-granular fluid inclusion trails, have been observed in quartz veins associated with BIFs of Kunchiganahalu. For constraining the mobilization-deposition conditions in the high PT region, the isochore for Type I inclusions is drawn for the density of 0.86 gm/cm³ for a C0₂-H₂O mixture with XCO₂ of about 0.6. Type II inclusions are of low salinity (<2wt % NaCl equivalent) H₂O variety with a density of 0.73 gm/cm³ Type III inclusions are of pure CO₂ variety with a density of 0.81 gm/cm³. Conditions of the mobilizing fluid are approximated by the intersection of the upper temperature for the assemblage pyrite-arsenopyrite which is fixed at 491°C and may be considered as a minimum estimate, as this assemblage and the CO₂-H₂O isochore correspond to the Type I fluid inclusions. The main depositional condition is constrained through the intersection of the isochores for the low salinity H₂O (Type II) and CO₂ (Type III). The identified conditions are 1900±150 bars at 425±150°C.The modification of a parental CO₂-H₂O+-NaCl fluid during boiling resulted in the decrcase in the activity of reduced sulphur in the hydrothermal solution which ultimately led to gold precipitation.

Keywords

Fluid Inclusions, Gold Mineralization, BIF, Kunchiganahalu, Chitradurga Belt, Karnataka, Dharwnr Craton.

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• Compositional Study of Spinels from Wajrakarur Pipe-10 (Anumpalle), Ananthapur District and its Significance in Diamond Prospectivity

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Authors

Abhijeet Mukherjee ¹, K. S. Rao ¹, E. V. S. S. K. Babu ², Gautam Roy ³

Affiliations
1 National Mineral Development Corporation Ltd., Khanij Bhawan, Masab Tank, Hyderabad - 500 028, IN
2 Department of Earth Sciences. University of Cambridge, Cambridge CB2 3EQ, GB
3 Applied Geochemistry Department, Osmania University, Hyderabad - 500 007, IN

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 52, No 6 (1998), Pagination: 677-682

Abstract

Geological Survey of India had recently discovered Wajrakarur pipe-10 and spinels from this pipe were analysed. Q-cluster analysis of these spinels based on Cr₂O_3, Al₂O_3, TiO₂ and MgO contents indicate the presence of S1, S3, S4, S5 and S10 groups. S1 group spinels are supposed to be cogenetic with diamond i.e., stable in the mantle within the P-T regime under which diamonds are known experimentally to form. The Cr/(Cr+Al) vs Fe/(Fe+Mg) plot also show that a few spinels are from the field of diamond inclusion chromites. This study suggests probable diamondiferous nature of the Anumpalle pipe.

Keywords

Geochemistry, Mineral Chemistry, Kimberlites, Diamond, Spinel, Andhra Pradesh.

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• Cluster Analysis and Nickel Thermometry of Garnet Xenocrysts from Majhgawan Diamondiferous Pipe, Panna District, Madhya Pradesh

Abstract Views :186  |  PDF Views:2

Authors

Abhijeet Mukherjee ¹, K. S. Rao ¹, Gautam Roy ², E. V. S. S. K. Babu ³

Affiliations
1 Natl. Min. Dev. Corp. Ltd., Khanij Bhawan, Masab Tank, Hyderabad - 500 028, IN
2 Applied Geochemistry Department, Osmania University, Hyderabad-500 007, IN
3 Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, GB

Source

Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 52, No 3 (1998), Pagination: 273-278

Abstract

Based on the Q-Cluster analysis of 536 garnet grains, the garnets of Majhgawan are classified as Group 1, Group 2, Group 9, Group 10 and Group 11. Group 10 garnets have very high MgO (21.2%) and moderate to high Cr₂O₃ (9.5%), combined with low CaO. MgO shows negative correlation with CaO and FeO and this cluster contains a large number of garnet inclusions in diamonds. The major element chemistry of these garnets confirm that they are moderately subcalcic and have high Crcontent with a well-defined Ca-Cr trend. Around twenty percent of garnets show harzburgitic trend indicating low to moderate grade of the pipe. Nickel thermometry has indicated a well-defined geotherm between 1150° - 1400°C and corresponds approximately to a slightly elevated 42 m W/m² conductive model. Garnets with temperature > 1150°C probably were derived from diamond stability field. Based on Ni-thennometry (using only lower cut-off) omega value is calculated (<30) which suggests an average grade upto 15 ctpht for Majhgawan pipe.

Keywords

Cluster Analysis, Geothermometry, Garnet, Diamond, Madhya Pradesh.

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