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Venkatasubramanian, V. S.
- Model Galena Ages from Karnataka and Surrounding Areas
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Authors
Affiliations
1 Dept. of Physics, Indian Institute of Science, Bangalore 560012, IN
2 Geological Society of India, Bangalore 560052, IN
3 Dept. of Mines & Geology, Race Course Road, Bangalore 560052, IN
1 Dept. of Physics, Indian Institute of Science, Bangalore 560012, IN
2 Geological Society of India, Bangalore 560052, IN
3 Dept. of Mines & Geology, Race Course Road, Bangalore 560052, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 18, No 2 (1977), Pagination: 49-52Abstract
Lead isotope ratios have been measured for selected samples from the Chitradurga and Kolar schist belts, the high-grade gneisses E of Karnataka (in Tamil Nadu) and Agnigundala of Cuddapahs. Most of the isotope data approximately fit a single-stage model and yield model ages at 3000 m.y., 2500 m.y., 1400 m.y. and 1100 m.y. The relations with other available age data are discussed.
- Primary and Metamorphic Rb-Sr Chronology in Some Areas of South Mysore
Abstract Views :184 |
PDF Views:141
Authors
Affiliations
1 Physics Department, Indian Institute of Science, Bangalore, IN
1 Physics Department, Indian Institute of Science, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 15, No 2 (1974), Pagination: 200-205Abstract
No Abstract.Full Text
- The Age of Some Gneissic Pebbles in Kaldurga Conglomerate Karnataka, South India
Abstract Views :183 |
PDF Views:118
Authors
Affiliations
1 Indian Institute of Science, Bangalore, IN
1 Indian Institute of Science, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 15, No 3 (1974), Pagination: 318-319Abstract
No Abstract.Full Text
- Geochronology of the Dharwar Craton - A Review
Abstract Views :151 |
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Authors
Affiliations
1 Indian Institute of Science, Bangalore, IN
1 Indian Institute of Science, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 15, No 4 (1974), Pagination: 463-468Abstract
The relevance of isotope age data in delineating the genetic relationships between the broad types of Archaean terrains of the Dharwar craton - viz., the greenstone belts, the granites and migmatites and the granulite facies complexes - is pointed out. The main results of the Rb-Sr isochron measurements carried out in this laboratory are summarized. The conglomerates have yielded the highest ages observed in this study, (3250 ± 150 m.y.), while two emplacement events at 2950 m.y. and 2600 m.y. have been observed in the migmatites and gneisses with evidence of metamorphic overprinting at 2300 m.y. and 2000 m.y., the latter being reflected in the Closepet event. While a whole rock isochron of 2475 m.y. has been observed for Chitradurga granites, the age relationships between the greenstones and granites still remains to be solved.- Model Lead Ages of Some Galenas from Karnataka
Abstract Views :193 |
PDF Views:119
Authors
Affiliations
1 Indian Institute of Science, Bangalore, IN
2 Geological Society of India, Bangalore, IN
1 Indian Institute of Science, Bangalore, IN
2 Geological Society of India, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 16, No 4 (1975), Pagination: 491-493Abstract
No Abstract.Full Text
- Rb-Sr Isochron. Ages of Gneisses in the Western Region of the Dharwar Craton
Abstract Views :163 |
PDF Views:160
Authors
Affiliations
1 CISL, Indian Institute of Science, Bangalore 560012, IN
2 Department of Mines and Geology, Bangalore 560001, IN
3 Department of Physics, Indian Institute of Science, B'lore 560012, IN
1 CISL, Indian Institute of Science, Bangalore 560012, IN
2 Department of Mines and Geology, Bangalore 560001, IN
3 Department of Physics, Indian Institute of Science, B'lore 560012, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 21, No 1 (1980), Pagination: 54-56Abstract
No Abstract.Full Text
- Solar Cells - Their Science, Technology, Applications and Economics
Abstract Views :194 |
PDF Views:116
Authors
Affiliations
1 Indian Insitute of Science, Bangalore 12, IN
1 Indian Insitute of Science, Bangalore 12, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 22, No 3 (1981), Pagination: 152-152Abstract
No Abstract.Full Text
- Origin of the Earth and the Moon
Abstract Views :206 |
PDF Views:128
Authors
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 21, No 10 (1980), Pagination: 521-521Abstract
No Abstract.Full Text
- Sulphur Isotope Abundance Variations in Sulphides of the Dharwar Craton-Part III: Hutti
Abstract Views :163 |
PDF Views:2
Authors
Affiliations
1 Department of Physics, Indian Institute of Science, Bangalore 560012, IN
2 Department of Mines & Geology, Bangalore 560001, IN
1 Department of Physics, Indian Institute of Science, Bangalore 560012, IN
2 Department of Mines & Geology, Bangalore 560001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 22, No 9 (1981), Pagination: 448-450Abstract
The δ34S values of pyrrhotite and arsenopyrite samples from the gold bearing quartz-sulphide reefs of Hutti have been measured. A narrow range of mantle-meteoritic values is observed indicating a magmatic-hydrothermal origin of the ores. An attempt is made to evaluate the solution parameters by the Ohmoto procedure, as outlined in Parts I and II.- Sulphur Isotope Abundance Variations in Sulphides of the Dharwar Craton-Part I: Kalyadi
Abstract Views :177 |
PDF Views:2
Authors
Affiliations
1 Indian Institute of Science, Bangalore 560 012, IN
1 Indian Institute of Science, Bangalore 560 012, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 22, No 8 (1981), Pagination: 391-395Abstract
Sulphur isotope abundance variations in chalcopyrite, pyrite and pyrrhotite samples from the sulphide deposits of Kalyadi have been measured with a double-collector mass spectrometer provided with digital ratio recording. The results fall into two groups - one with a near-zero per-mil value and another with a small positive value ∼5‰. Data on coexisting sulphide minerals enable temperatures of deposition to be calculated, these being low ∼250° C. The Ohmoto-procedure is adopted, and the range of δ34S values of the minerals explained by assuming an initial total sulphur δ34STS value and a range of pH and fO2 values that are plotted on an fS2 - fO2 diagram consistent with the stability fields of the minerals.- Sulphur Isotope Abundance Variations in Sulfides of the Dharwar Craton - Part II: Ingaldhal
Abstract Views :194 |
PDF Views:2
Authors
Affiliations
1 Indian Institute of Science, Bangalore 560 012, IN
1 Indian Institute of Science, Bangalore 560 012, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 22, No 8 (1981), Pagination: 395-398Abstract
In this sequel to the previous note, we describe the results of δ34S measurements on sulphides of the Ingaldhal deposit. A component with near-zero permit values is superposed on a possibly larger component with positive δ34S values ∼+10‰. The spread can be explained in terms of change in the solution parameters (T, pH and fO2) of the source-fluid, these being represented by fs2-fO2 diagrams. An area on this diagram, sets constraints on the solution parameters during deposition, as indicated.Keywords
No Keywords- Lead Age Measurements on Galenas from Peninsular India
Abstract Views :171 |
PDF Views:4
Authors
Affiliations
1 Department of Physics, Indian Institute of Science, Bangalore 560 012, IN
1 Department of Physics, Indian Institute of Science, Bangalore 560 012, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 23, No 5 (1982), Pagination: 219-225Abstract
Measurements of lead isotope ratios on some Indian galenas and calculation of single-stage model ages were presented in a previous paper. Techniques have been improved since then, and more samples from some of these areas and several new samples have been measured. The present measurements cover a wide age-span, Eocene to Archaean (∼3300 m.y.) and the Pb-isotope abundances are not inconsistent with a 2-stage evolution of lead which show an episodic change in μ-value at ∼ 3000m.y. Model ages and μ-values have been calculated using single and double-stage models and an attempt made to interpret these values.- Geochemistry and Petrogenesis of the Peninsular Gneisses, Dharwar Craton, India
Abstract Views :151 |
PDF Views:4
Authors
Affiliations
1 Department of Mines & Geology, Bellary 583101, IN
2 Department of Physics, Indian Institute of Science, Bangalore 560012, IN
3 DMS RDE, P.B. 320, Kanpur 208013, IN
1 Department of Mines & Geology, Bellary 583101, IN
2 Department of Physics, Indian Institute of Science, Bangalore 560012, IN
3 DMS RDE, P.B. 320, Kanpur 208013, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 25, No 9 (1984), Pagination: 570-584Abstract
Systematic measurement of the abundances of major, trace and rare earth elements has been carried out on a number of samples of the Peninsular gneisses. The data suggests that the Peninsular gneisses could be broadly differentiated into Western tonalitic group and an Eastern granodioritic group. The dividing line roughly corresponds to the western margin of the Chitradurga greenstone belt. The Geochemical data also suggests that bulk of the Peninsular gneisses are magmatic. Critical differences in trace and rare earth element abundances are observed between the western tonalites and the eastern granodiorites.- Rb-Sr Ages of Cordierite-Gneisses of Southern Karnataka
Abstract Views :179 |
PDF Views:112
Authors
Affiliations
1 Indian Institute of Science, Bangalore, IN
2 Geological Society of India, Bangalore, IN
1 Indian Institute of Science, Bangalore, IN
2 Geological Society of India, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 17, No 4 (1976), Pagination: 557-561Abstract
The cordierite-gneisses of southern Karnataka give Rb-Sr ages of 3010±90 rn.y. indicating jheir relationship to 3000 m.y. event in the Dharwar craton, for which evidence is available in a number of areas.Full Text