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Reddy, U. S. N.
- Utility of Ground Spectral Reflectance Data in Remote Sensing for Discriminating Lithounits
Authors
1 Photogeology and Remote Sensing Division, AMSE Wing, Geological Survey of India, 2, Church Street, Bangalore 560001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 33, No 2 (1989), Pagination: 104-115Abstract
Ground spectral reflectances have been collected over various lithounits in Cuddapah basin and adjoining crystallines, employing the portable spectre-radiometer, designed by the I.S.R.O. Satellite Centre. With the help of the spectral signatures it is found feasible to discriminate the argillaceous, arenaceous and calcareous components, post-kinematic intrusives and gneisses, thus facilitating the intra- and inter-group separabilities
In general, the arenaceous component is characterised by electron transition bands, perhaps indicating relatively low degree of weathering than the calcareous and argillaceous components. Siliceous, nonsiliceous, ferro-dolomites and gossan zones have been identified by their spectral differences. The photon absorption bands in the visible region and lattice absorption bands in the Infra-red region are due to Fe or Mn charge transfer and the formation of secondary minerals during weathering respectively. The molecular absorption bands in the case of quartzites is attributed to the inherent compositional impurity in the rock itself. A carbonate absorption band is identified tentatively around 0.85 to 1.0 micron. The reflectance peak in the green region is attributed to the presence of chlorite/sericite. The field characteristics and spectral reflectance data evaluation for the phosphoritic horizons of Cuddapah basin have not indicated the feasibility of aerial multispectral scanner survey. Differential derivative reflectance quantities have been computed for each lithounit for obtaining optimum enhanced ratioed data products in the computer processing of LANDSAT digital data. This type of ground truth studies are of paramount importance for the purpose of classification of cover types as a basic input in digital processing of remote sensing data.
- Computer Classification of Landsat Data for Targeting Gem-Bearing Tracts in Karnataka State, India
Authors
1 AMSE Wing, GSI, Photo-geology and Remote Sensing Division 2, Church Street, Bangalore 560001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 34, No 5 (1989), Pagination: 540-544Abstract
Precious and semi-precious stones are found associated with colluvial/gravel landforms and in schistose rocks associated with vein quartz/pegmatites. Utilising the LANDSAT-4 digital data, computerised classification has been adopted using known gem-bearing locations as training sets with the principal objective of delineating possible target areas for gemstone prospecting in Bangalore, Tumkur, Mandya and Mysore districts of southern Karnataka, India.- Occurrence of Fullerene Bearing Shungite Suite Rock in Mangampeta Area, Cuddapah District, Andhra Pradesh
Authors
1 Geological Survey of India, Seminary Hills, Nagpur, IN
2 Stanford University, San Fransisco, US
3 Pune University, Pune, IN
4 Cihergen Biosystesms, San Fransisco, US
5 Geological Survey of India, Hyderabad, IN
6 Geological Survey of India, AMSE Wing, Bangalore, IN
7 National Geophysical Research Institute, Hyderabad - 500007, IN
8 Seminary Hills, Nagpur, IN
9 Geological Survey of India, Jaipur, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 69, No 1 (2007), Pagination: 25-28Abstract
The black carbonaceous slates, interbedded within the Proterozoic volcano-Sedimentary sequence of Cuddapah Supergroup in the vicinity of Mangampeta are found to the fullerene bearing and belonging to the shungite suite of rocks. Presence of fullerene in powdered rock samples is identified from the characteristic spectra obtained by laser desorption/Ionization spectrometry. This is further confirmed by making soxhlet extract using toluene and exposing it to different laser powers to avoid any possibility of it being analytical artifact. Both carbon allotrope fullerene C60 and C70 are identified within these rocks. Two geological samples collected from the prominent rock units within this thick sequence of black carbonaceous unit belonging to the shungite suite of rock are found to have fullerenes. This reporting of fullerene is first of its kind from any geological material from India. The only other occurrence of fullerenes in geological samples is recorded from the Shunga locality of the Karelean province of Russia.Keywords
Fullerenes, Shungite, Carbonaceous Slate, Barite, Mangampeta, Cuddapah District, Andhra Pradesh.- Occurrence of Fullerene Bearing Shungite Suite in Mangampeta Area, Cuddapah District, Andhra Pradesh
Authors
1 Analytical Research Laboratory, Department of Polymer and Petroleum Engineering, MIT Engineering College, Kothrud, Pune - 411 038, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 71, No 4 (2008), Pagination: 590-591Abstract
No Abstract.Full Text
- Evaluation of Aeromagnetic Data and Regional Geological Interpretation for a Part of the Cuddapah Basin
Authors
1 Airborne Mineral Surveys and Exploration Wing, Geological Survey of India, No.2, Church Street, Bangalore 560001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 25, No 10 (1984), Pagination: 666-676Abstract
Based on total intensity aeromagnetic profile data across the Cuddapah Basin, it is possible to distinguish the Cumbum and Bairenkonda Formations of Nallamalai Group. Further subdivision within individual intercalated dolomites and quartzites of Cumbum Formation is also found feasible. This discriminatory criterion can be used to guide mineral exploration, especially in the dolomites of Cumbum Formation. The magnetic variations along the strike of the Cumbum Formation is considered to be due to minor undulations in basin geometry, ref1ecting palaeogeography of pre-Cumbum period. The high magnetic response in Tadpatri and Vempalli Formations is mostly due to their association with basic volcanism.
All along the eastern margin of the basin, there is an ascending magnetic trend which coincides with a thrust. The geometry of Iswarakuppam dome is inferred to be asymmetric and with a tilt towards cast and/or controlled by a crustal fracture. The relative high magnetic response and discordant trend over Kurnool Group of rocks in the western part of the Kunderu Basin is attributed to the occurrence of the basement at shallow levels locally. Regional and areal trend surfaces have been estimated and causative magnetic responses due to basement and overlying metasediments are evaluated. For trend surface analysis, window sizes have been determined and computerization is suggested. From the LANDSAT imagery interpretation, a three stage basin evolutionary trend has been inferred.
A northwest-southeast tectonic break near Cumbum town is proposed, along which the basin oscillated, causing shallowing of the basin to the north and deepening to the south. Further, it is postulated that the northern and southern blocks tilted to east and west respectively moving on a northeast-southwest axis, resulting in the basement rise in the northwest and southeastern parts and gentle slope in the northeastern and southwestern parts in the area of study.