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Rao, K. S.
- Ion Exchange Properties of Lateritic Soil from Calicut Kerala
Authors
1 Department of Civil Engineering, Indian Institute of Technology, Kanpur 208016, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 25, No 7 (1984), Pagination: 466-470Abstract
The lateritic soils developed over Precambrian crystalline rocks near Calicut have relatively high Cation Exchange Capacity. At the same time, the soils are highly efficient for phosphate uptake. Both of these properties are traced to the presence of halloysite of intermediate hydration in the soils. Experimental results have been interpreted in terms of the structure of soil minerals.- Purana Basins of Peninsular India
Authors
1 Geological Survey of India, Hyderabad, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 26, No 7 (1985), Pagination: 496-504Abstract
No Abstract.- Textural Characteristics of the Visakhapatnam Shelf Sediments
Authors
1 Department of Geology, Andhra University, Waltair 530003, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 33, No 1 (1989), Pagination: 38-47Abstract
Textural parameters, viz., mean, standard deviation, skewness and kurtosis and CM patterns in respect of 150 offshore sediments from the continental shelf off Visakhapatnam enabled delineation of two distinct sedimentary facies, one in the northern sector (Visakhapatnam - Bheemunipatnam) and the other in the southern sector (Visakbapatnam - Pudimadaka). The sedimentary facies in northern sector includes sands (from coast up to 37 m) followed offshore by silty sands (up to 50 m), sandy silt (up to 70 m) and silts (up to 80 m) and that in the southern sector, sands (up to 30 m), silty sands (between 30 - 40m and 50 - 80 m) followed offshore by sandy silts (between 40 - 50 m). There is a progressive seaward fining of sediments in the southern sector, whereas in the northern sector the fining is towards both sea and land. Fining of sediments with depth, a feature common to open shelves, is attributed to wave action. Distribution of medium sand zone in the northern sector between 15 to 40 m along the coast has been considered to be the result of dumping of dredged out material from the nearby port area. A major part of the study area is floored by poorly-sorted sediments. Skewness values of the sediments in the southern sector increase uniformly with depth whereas they show more complex pattern in the northern sector. Leptokurtic sediments bordering the coast in the northern sector indicate removal of fines through wave and current activity. CM diagram indicates the prevalence of low to moderate current activity in the south and highly turbulent zones in the north.- Majhgawan Diamondiferous Pipe, Madhya Pradesh, India - A Review
Authors
1 National Mineral Development Corporation Ltd., Hyderabad-500 028, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 45, No 2 (1995), Pagination: 175-189Abstract
The alkaline ultrabasic diatreme at Majhgawan has an idealised geological setting being intruded into the platformal Kaimur sandstones of the Lower Vindhyan Supergroup (1400-1100 Ma) overlying cratonic Bundelkhand granite basement (2550 Ma) which is a typical archon as per Janse (1992). Recent Rb/Sr age data indicate 1042 Ma (Smith 1992) and 1067 Ma (Anil Kurnar and Gopalan 1992) for the Majhgawan pipe. The pipe with surface dimension of 500 × 320 m is a carrot shaped body reminiscent of a typical kimberlite with minimal erosion. The pipe rock has been classified as lamproite by Scott Smith (1989, 1992a) who has termed it as olivine lamproitic lapilli tuff of crater facies. High TiO2(4-6%), less abundance of typical heavy indicator minerals (HIM) like group-10 pyrope garnet and ilmenite and overall petrological characters of the pipe strongly reflect lamproite nature. High amounts of certain minor elements such as Ba (3000 ppm), Sr (1000 ppm) and REE (high La, U/Th ratio) also indicate its lamproitic character.On the other hand the typical carrot shape of the plug, almost concentric distribution of diamonds, mode of presence of mantle-derived xenocrysts, overall chemistry with high MgO(25%) low K2O(1%) and fair amounts of Cr and Ni are highly characteristic of kimberlitic nature. Broad petrographic characters coupled with abundance of xenocrysts and occurrence of country rock xenoliths and geochemical charecteristics suggest it is in several aspects typical kirmberlite rather than lamproite. The garnet population with fair amount of harzburgitic pyrope and larger share of lherzolitic variety indicate characteristics almost intermediate between kimberlite and lamproite.
Irrespective of the nature of the diatreme in any exploration model for search of new primary sources in the area, the spesific nature of HIM of the Majhgawan rock has to be kept in view (i.e.rather less abundance of garnet that too more of group-9 type, predominance of high magnesia spinellchromite, absence of ilmenite etc). The Majhgawan diamonds (42% gem) are predominantly curve faced modified forms indicating signs of resorption.
Keywords
Kimberlite, Lamproite, Diamond, Majhgawan, Panna, Madhya Pradesh.- Geothermometry and Oxygen Barometry of Coexisting Iron-Titanium Oxides of Majhgawan Diamondiferous Pipe, Madhya Pradesh
Authors
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: 55-60Abstract
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.- Chemistry of Phlogopite Megacrysts in Majhgawan Diamondiferous Pipe, Panna, Madhya Pradesh
Authors
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: 203-206Abstract
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.- Chemistry of Garnet and Ilmenite from Majhgawan Diamondiferous Pipe, Panna District vis-a-vis Diamond Potential and Preservation
Authors
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: 441-448Abstract
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.- Whither Field Geology?
Authors
1 Flat # 202, 'Narmisam 'Srinagar Colony PO Hyderabad - 500 073, IN
2 Flat # 401, Srinilaya Estate Ameerpet, Srinagar Colony P O Hyderabad - 500 073, IN
3 Centre for Earth Science Studies Thiruvananthapuram, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 64, No 6 (2004), Pagination: 827-828Abstract
No Abstract.- Closure of Kudremukh Iron Ore Mines
Authors
1 Hyderabad, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 62, No 5 (2003), Pagination: 649-649Abstract
No Abstract.- Precambrian Geology and Mineral Wealth of Central India
Authors
1 Plot-22, Flat #202, Naimisain Srinagar Colony P. O. Hyderabad - 500 073, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 64, No 3 (2004), Pagination: 368-369Abstract
No Abstract.- Compositional Study of Spinels from Wajrakarur Pipe-10 (Anumpalle), Ananthapur District and its Significance in Diamond Prospectivity
Authors
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: 677-682Abstract
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 Cr2O3, Al2O3, 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.- Cluster Analysis and Nickel Thermometry of Garnet Xenocrysts from Majhgawan Diamondiferous Pipe, Panna District, Madhya Pradesh
Authors
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