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Mishra, V. P.
- Kimberlites, Lamproites and Lamprophyres of India: A Petrographic Atlas
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Authors
Affiliations
1 Geological Survey of India, AMSE Wing, Vasudha Bhavan, Kumaraswamy Layout, Bangalore - 560 078, IN
1 Geological Survey of India, AMSE Wing, Vasudha Bhavan, Kumaraswamy Layout, Bangalore - 560 078, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 69, No Spl Iss 3 (2007), Pagination: 467-504Abstract
A pictorial display of some of the kimberlites, lamproites and lamprophyres of India, is given in this work. This would give an idea about the texture and mineralogy of these rocks from different cratonic regions of the Indian shield.Keywords
Kimberlites, Lamproites, Lamprophyres, Petrography, Atlas.
- Study of Structural Pattern through Aeromagnetic Data for Mineral Prospecting and Kimberlite Clan Rocks in an Area around Mahbubnagar, A.P.
Abstract Views :201 |
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Authors
Rajendra Sharma
1,
Ch. V. V. S. Murthy
1,
V. P. Mishra
1,
B. V. Nagaraju
1,
H. C. Gouda
1,
R. K. Singh
1
Affiliations
1 Geological Survey of India, GMC Division, AMSE Wing, Vasudha Bhavan, Kumaraswamy Layout, Bangalore - 560 078, IN
1 Geological Survey of India, GMC Division, AMSE Wing, Vasudha Bhavan, Kumaraswamy Layout, Bangalore - 560 078, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 72, No 2 (2008), Pagination: 175-189Abstract
The qualitative interpretation of aeromagnetic map of an area around Mahbubnagar, indicated several linears and discontinuities, which suggest the presence of various magnetic bodies and fractures, faults, and shears. The magnetic discontinuities trend in NW-SE, WNW-ESE, NE-SW, N-S and E-W directions. The quantitative interpretation indicated three magnetic interfaces at the depths of 4.5 km, 1.3 km and 670 m from the plane of observation at 675 m above m.s.l. The magnetic maps of different layers prepared by matched filtering have helped in understanding the structural setup. The study of these maps has indicated that major discontinuities (fractures/faults) extend to greater depths. The 2-D modelling revealed the dips of the bodies varying between 3°-27° indicating the near horizontal type of sources excepting the one with 69° dip. The depths to the top of these bodies were found to vary between 308 m-1180 m from the plane of observation. The 3-D prism modelling of selected anomalies indicated that most of them are near horizontal type of sources except a few. The depths to the top of these prism bodies vary between 440 m- 831 m and to the bottom between 682 m-7136 m from the plane of observation. This shows that majority of the magnetic bodies are emplaced in the surficial and shallow layers and few extend to greater depths. Based on this study, 15 blocks were identified as potential areas for mineral prospecting and also for possible emplacement of Kimberlite clan rocks (KCR).Keywords
Aeromagnetic, Mineral Prospecting, Mahbubnagar, Andhra Pradesh.- Structural Study through Aeromagnetic Data for Mineral Prospecting in Betul-Chhindwara Area, M. P.
Abstract Views :188 |
PDF Views:3
Authors
Rajendra Sharma
1,
Ch. V. VS. Murthy
1,
V. P. Mishra
1,
B. V. Nagaraju
1,
H. C. Gouda
1,
R. K. Singh
1
Affiliations
1 Geological Survey of India, GMC Division, AMSE Wing, Vasudha Bhavan, Kumaraswamy Layout, Bangalore - 560 078, IN
1 Geological Survey of India, GMC Division, AMSE Wing, Vasudha Bhavan, Kumaraswamy Layout, Bangalore - 560 078, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 71, No 6 (2008), Pagination: 815-826Abstract
The aeromagnetic map of Betul-Chhindwara area, contains two magnetic domains namely 'A' representing high amplitude anomalies falling over Deccan Traps and domain 'B' represented by moderate amplitude anomalies falling over gneiss and Gondwana Supergroup. The qualitative interpretation of aeromagnetic data has brought out several linears and discontinuities, which show the presence of various magnetic bodies and fractures/faults/shears/contacts respectively. The magnetic linears were found to trend mainly in ENE-WSW direction and few in E-W, NE-SW and NW-SE directions. The prominent magnetic discontinuities trending in ENE-WSW directions were found to be intersected by NW-SE, NE-SW and nearly N-S trending discontinuities at places. One of these prominent discontinuities was found to fall along granitic gneiss and others at the contact of gniesses with Gondwana Supergroup in northern part and with Deccan Traps in southern part. One prominent discontinuity was found within Gondwana Supergroup in the northern part and another in the southeastern part over the known Gavilgarh fault. The magnetic discontinuity obtained in the gneissic complex was found to fall over the known sulphide mineralisation near Banaskhapa-Piparia etc. and thus assumes importance for prospecting sulphide minerals all along the discontinuity.The quantitative interpretation was carried out by computing the radial power spectrum and by 2-D modelling of selected anomalies. The Radial power spectrum yielded two interfaces at the depths of 0 871 km and 9 461 km from observation plane (1080 m above msl). The shallow layer map is similar to that of the terrain corrected map whereas the deep layer map indicated the gradients corroborating with the discontinuities mentioned above excepting the one falling over granitic gneiss which was reflected as a broad elongated magnetic low. The results of 2-D modelling over ten selected anomalies suggest that most of the bodies are very shallow excepting two The dips of most of the bodies were found m between 6°-25° and few between 32°- 48°.
Keywords
Aeromagnetic, Mineral Prospecting, Betul, Madhya Pradesh.- Discovery of Animal Eggs and Embryos from the Ediacaran (Terminal Proterozoic) Chambaghat Formation, Krol Group, Himachal Lesser Himalaya
Abstract Views :233 |
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Authors
Affiliations
1 Palaeontology Division, Geological Survey of India, Sector-E, Aliganj, Lucknow - 226 024, IN
1 Palaeontology Division, Geological Survey of India, Sector-E, Aliganj, Lucknow - 226 024, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 74, No 4 (2009), Pagination: 498-502Abstract
The globular to suboval microfossils with distinctively ornamented outer coverings interpreted as animal eggs and embryos have been discovered from the black phosphatic chert lentils of the Ediacaran (Terminal Proterozoic) Chambaghat Formation (Krol sandstone), Krol Group, Himachal Lesser Himalaya, India. Similar animal eggs and embryos have earlier been recorded only from the phosphorites of the uppermost Neoproterozoic Doushantuo Formation (Ca. 570±20 Ma) exposed at Weng'an, South China. Present record of eggs and embryos is comparable with extant eggs and embryos of cnidarians and bilaterians like molluscs, annelids and arthropods. The eggs and embryos from the Terminal Proterozoic rocks of India are the only one recorded from the equivalent stratigraphic horizon outside China. This discovery of eggs and embryos adds to the understanding the evolutionary trends in the Proterozoic metazoan life.Keywords
Eggs, Embryos, Ediacaran, Proterozoic, Krol Group, Himachal Lesser Himalaya.References
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