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Co-Authors
- K. S. Anantha Murthy
- M. Basavanna
- C. R. L. Friend
- I. R. Vasant Kumar
- B. P. Radhakrishna
- T. C. Devaraju
- Peter W. Uitterdijk Appel
- J. J. Peucat
- M. Santosh
- M. Jayananda
- S. P. Venkata Dasu
- T. M. Ramakrishnan
- M. Ramakrishnan
- M. Jayanand
- N. Shadakshasra Swamy
- E. C. Hansen
- R. J. Stern
- P. J. Kenny
- Jean-Francois Moyen
- Jayananda Mudlappa
- Anne Nedelec
- Herve Martin
- Bernard Auvray
- S. Viswanathan
- Yamuna Singh
- K. Surya Prakash Rao
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Mahabaleswar, B.
- Journal of Asian Earth Sciences-Special Issue on Alkaline and Carbonatitic Magmatism and Associated Mineralization
Abstract Views :202 |
PDF Views:130
Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore - 560 056, IN
1 Department of Geology, Bangalore University, Bangalore - 560 056, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 56, No 3 (2000), Pagination: 344-345Abstract
No Abstract.Full Text
- Pressure - Temperature Estimates of the Iron Formations of Sivasamudram Area, Karnataka
Abstract Views :162 |
PDF Views:5
Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore, IN
2 Depat1ment of Geology, Karnataka University, Dharwad, IN
1 Department of Geology, Bangalore University, Bangalore, IN
2 Depat1ment of Geology, Karnataka University, Dharwad, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 25, No 9 (1984), Pagination: 564-569Abstract
Through a consideration of major element chemistry it is inferred that the orthopyroxenes and clinopyroxenes of the iron formations are ferrohypersthene and ferroaugite respectively, whereas the garnets belong to pyralspite series. The opx and garnets are rich in Mn content, which may be due to bulk composition of the host rock and oxygen fugacity. The P-T estimates give values of 7.5 to 8 Kbars and 607°C to 657°C.
- The Kunduru Betta Ring Intrusion, Malavalli, Karnataka, South India
Abstract Views :223 |
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Authors
Affiliations
1 Department of Geology and Physical Sciences, Oxford Polytechnic, Headington, Oxford OX3 OBP, GB
2 Department of Geology, Bangalore University, Jnana Bharathi, Bangalore 560056, IN
1 Department of Geology and Physical Sciences, Oxford Polytechnic, Headington, Oxford OX3 OBP, GB
2 Department of Geology, Bangalore University, Jnana Bharathi, Bangalore 560056, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 26, No 2 (1985), Pagination: 73-83Abstract
Field evidence is presented which allows the syenitic and granitic rocks occurring at Kunduru Betta to be reinterpreted as a ring intrusion. The syenitic rocks were intruded first and are divided into three major types based upon their field, textural and mineralogical characteristics which may be related to the conditions of crystallization.
Crystallization began with saturated syenite and ended with markedly silica oversaturated Quartz syenite. The granitic stock in the centre of the complex clearly crosscuts the syenitic rocks and is itself cut by later aplite dykes which also extend into the syenite and the country rocks. Both the syenite and the granite display lithological and sub-vertical mineralogical layering which is described for the first time.
- Migmatites
Abstract Views :175 |
PDF Views:117
Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore, IN
1 Department of Geology, Bangalore University, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 26, No 12 (1985), Pagination: 894-895Abstract
No Abstract.Full Text
- Geochemistry of the Archaean Gneiss Complex and Associated Rocks of the Kanakapura Area, Karnataka, South India
Abstract Views :179 |
PDF Views:2
Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore, IN
2 Department of Geology & Physical Sciences, Oxford Polytechnic, Headington, Oxford OX3 OBP, GB
1 Department of Geology, Bangalore University, Bangalore, IN
2 Department of Geology & Physical Sciences, Oxford Polytechnic, Headington, Oxford OX3 OBP, GB
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 27, No 3 (1986), Pagination: 282-297Abstract
The area of present investigation forms a part of the Archaean high-grade gneiss terrain of Karnataka. The rocks comprise both acid and basic lithologies and involve the late Archaean Closepet granite. Petrographically the acid rocks span the range, tonalite to granite, whilst the basic rocks are amphibolites and two-pyroxene granulites. The acid 'rocks have calc-alkaline affinities and resemble those from the transition zone to the east. Trace elements show them to be relatively undepleted with K/Rb ratios of >500. Simulated REE patterns of gneisses reveal that there are three broad groups: two of which are steep, but at different REE abundances, suggesting high pressure evolution; and one relatively flat group suggesting low pressure evolution. The basic rocks have a tholeiitic affinity, but are clearly separate, the granulite facies types being slightly more magnesian. The trace element chemistry of these basic rocks has been disturbed by migmatization. The REE patterns of Closepet granite are steep and may be related to the partitioning of accessory minerals such as allanite. An attempt is made to establish the relative position of the granulite facies metamorphism with respect to the regional fabric and retrogression.- Precambrian Banded Iron Formations of India
Abstract Views :192 |
PDF Views:145
Authors
Affiliations
1 Bangalore University, Bangalore, IN
1 Bangalore University, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 26, No 11 (1985), Pagination: 825-832Abstract
No Abstract.Full Text
- Banded Iron-Formation of India
Abstract Views :149 |
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Authors
Affiliations
1 Geological Society of India, IN
1 Geological Society of India, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 28, No 2&3 (1986), Pagination: 71-91Abstract
No Abstract.- Mineral Chemistry of the Silicate Mineral Phases of Banded Iron-Formation of High-Grade Region, Karnataka
Abstract Views :150 |
PDF Views:3
Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore 560056, IN
1 Department of Geology, Bangalore University, Bangalore 560056, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 28, No 2&3 (1986), Pagination: 165-178Abstract
Analytical data on the silicate mineral phases, namely, orthopyroxene, clinopyroxene, lamellar pyroxene, pyroxenoid, gamet, amphibole and biotite of ironformation from high-grade region, Karnataka are presented. It is inferred that Opx and Cpx of the iron-formation are ferro-hypersthene and ferro-augite respectively, whereas the pyroxenoid is a pyroxferroite. Garnets belong to pyralspite series. Amphiboles are represented by grunerite, edenite and ferroan pargasitic hornblende. Lamellar pyroxenes are represented by clinopyroxene and orthopyroxene containing lamellae which are Ca-poor and Ca-rich respectively. The lamellar nature of the pyroxene appears to be related to silica activity, P-T and oxygen fugacity. Orthopyroxene and garnet are rich in Mn content, which may be due to bulk composition of the host rock and oxygen fugacity. Pressure and Temperature estimates give values of 7 to 8 kbars and 600° to 650°C.- Secular Trends in Rare Earth Element Patterns of Precambrian Iron-Formations from India and Greenland
Abstract Views :200 |
PDF Views:4
Authors
Affiliations
1 Geological Survey of Greenland, DK 2100, Copenhagen, Denmark, GB
2 Dept. of Geology, Bangalore University, Bangalore, IN
1 Geological Survey of Greenland, DK 2100, Copenhagen, Denmark, GB
2 Dept. of Geology, Bangalore University, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 32, No 3 (1988), Pagination: 214-226Abstract
Rare earth element (REE) analysis have been carried out by neutron activation on samples of iron-formation from southern India and from West Greenland. The investigated iron-formations range in age from about 1800 m. y. to more than 3000 m. y. The different iron-formations have undergone very diffeferent metamorphic histories, from the virtually unmetamorphosed iron-formation in West Greenland, through amphibolite to granulite facies metamorphism in southern India.
The results clearly demonstrate that europium anomalies cannot be used as indicators for oxygen contents of the Precambrian atmosphere. A secular trend has been established in the Precambrian iron-formations, whereby the oldest iron-formations display only slight fractionation of light REE relative to heavy REE, and this fractionas tion increases with decreasing age of the iron-formations.
- 2.9 b.y. Rb-Sr Age of the Granulite Facies Rocks of Satnur-Halagur and Sivasamudram Areas, Karnataka, South India
Abstract Views :216 |
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Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore-560056, IN
2 Centre Armoricain d'Etudes Structurales des Socles, CNRS, Laboratoire de geochronologie et geochimie isotopique, 35042 Rennes, FR
1 Department of Geology, Bangalore University, Bangalore-560056, IN
2 Centre Armoricain d'Etudes Structurales des Socles, CNRS, Laboratoire de geochronologie et geochimie isotopique, 35042 Rennes, FR
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 32, No 6 (1988), Pagination: 461-467Abstract
Preliminary Rh-Sr isotopic studies of the granulites occurring SW of Kabbaldurga were undertaken to verify the possibility of an earlier granulite facies event. The Rb-Sr data obtained gives an imperfect isochron age of 2950 ± 234 m.y. with an initial ratio of 0.7032 ± 22 (MSWD = 52). The age obtained may correspond to subconcomitant protolith-metamorphism age or metamorphism alone. The high error may be due to non-cogenetic nature of the rocks analysed or a small disturbance of the Rb-Sr system during the 2500 m.y. high-grade event. The present study indicates probability of the occurrence of an early granulite facies event prior to 2500 m.y.- Fluid Evolution in the Closepet Granite: A Magmatic Source for CO2 in Charnockite Formation at Kabbaldurga ?
Abstract Views :191 |
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Authors
Affiliations
1 Department of Geosciences, Osaka City University, Osaka 558, JP
2 Department of Geology, Bangalore University, Bangalore 560 056, IN
1 Department of Geosciences, Osaka City University, Osaka 558, JP
2 Department of Geology, Bangalore University, Bangalore 560 056, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 38, No 1 (1991), Pagination: 55-65Abstract
Fluid inclusion studies in the Closepet granite reveal the common occurrence of trapped fluids which show melting temperatures and laser excited Raman spectral-characteristics close to those for pure CO2. The quartz-bound inclusions in this polyphase intrusive define two major genetic categories: an earlier CO2-rich fluid with only minor traces of water and a late mixed carbonic-aqueous fluid. Compelling evidence for fluid immiscibility is preserved by coexisting inclusions with widely varying filling ratios and similar filling temperatures. Salinities upto 10 wt per cent NaCl are estimated from microthermometry, which ascribe relatively higher temperatures for fluid immiscihility in the CO2-H2O system. Our results indicate that this late Archaean granite body which truncates regional metamorphic isograds has probably been a major carrier of CO2-rich volatiles, subsolidus exsolution and channelisation of which along structural locales caused incipient dehydration and the formation of Kabbaldurga-type arrested granulites in many adjacent localities. Our model seeks to associate advective transfer of both heat and volatiles required for dehydration with the Closepet magma.Keywords
Closepet Granite, Fluid Inclusions, Immiscibility, Charnockite, Dehydration.- Atlas of Structures and Textures in Some Rocks of Southern India
Abstract Views :187 |
PDF Views:100
Authors
Affiliations
1 University of Bangalore, Bangalore, IN
1 University of Bangalore, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 38, No 3 (1991), Pagination: 336-336Abstract
No Abstract.Full Text
- The Generation and Emplacement of Closepet Granite During Late Archaean Granulite Metamorphism in Southeastern Karnataka
Abstract Views :322 |
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Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore 560 056, IN
1 Department of Geology, Bangalore University, Bangalore 560 056, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 38, No 4 (1991), Pagination: 418-426Abstract
In the amphibolite-granulite facies transition zone of southeastern Karnataka a typical metamorphic-anatectic sequence is exposed. In this zone large scale melting of basement gneisses during late Archaean granulite metamorphism has led to the generation of the Closepet granite. Field evidence suggests a space-time relationship between charnockite development, migmatite formation and generation of the Closepet granite. This is also substantiated by U-Pb and Pb-Pb isotope data. At the southern end of the Closepet granite, conventional petrological data and oxygen isotope work suggest that CO2-rich fluid phase of subcrustal origin was instrumental in granulite metamorphism and anatexis. The Southern Closepet granite is highly heterogeneous and displays a very complex polyphase internal structure. Based on texture and cross cutting relationships, four major granite phases are recognised. The P-T conditions inferred from mineralogic geothermometry and geobarometry indicate that granite melts were generated at midcrustal levels. The spatial association of migmatites and gradational contacts suggest that the granite in the transition zone did not rise far from its source region. The occurrence of ductile mylonites and augen gneisses further north of the study area indicates a major shear control in the generation of the Closepet granite. A model involving collision of eastern and western crustal blocks along a N-S dividing line is the possible tectonic set-up for evolution of the Closepet granite.Keywords
Closepet Granite, Anatexis, Migmatites, Charnockite, CO2 Fluid Phase, Karnataka.- Sargur-Dharwar Relationship Around the Komatiite-Rich Jayachamarajapura Greenstone Belt in Karnataka
Abstract Views :210 |
PDF Views:1
Authors
Affiliations
1 Geological Survey of India, A.M.S.E. Wing, Church Street, Bangalore-560001, IN
2 Department of Geology, Bangalore University, Bangalore-560056, IN
1 Geological Survey of India, A.M.S.E. Wing, Church Street, Bangalore-560001, IN
2 Department of Geology, Bangalore University, Bangalore-560056, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 38, No 6 (1991), Pagination: 577-592Abstract
New geological and preliminary geochemical data presented here from J ayachamarajapura (JC Pura) reinforce the idea of orogenic separation of two sequences across a deformed angular un confonnity . The JC Pura belt forms a major structural dome linking a trail of enclaves to the north and south. Its main lithology is altered komatiites preserving excellent polyhedral joints, pillows, ocelli and spinifex texture. These peridotitic komatiites are closely associated with the basaltic komatiites now represented by dark shiny amphibolites.Cherty quartzites and BIF form minor units. This association is typical of the older greenstones (Sargur Group) of Kamataka. These lithologies are overlain unconformably by the basal quartz-pebble conglomerate and associated amygdular metabasalt - crossbedded quartz arenite alternations constituting the Bababudan Group in the Kibbanahalli arm of Chitradurga schist belt. Kibbanahalli volcanics are mainly tholeiites as distinct from the dominant komatiites of the JC Pura belt. Such chemical distinction, but of a different kind, is reported recently from the Kalasapura area of Bababudan belt. JC Pura area therefore offers yet another spectacle of Sargur-Dharwar orogenic discrimination in Kamataka.Keywords
Jayachamarajapura Greenstone Belt, Kibbanahalli, Komatiites, Angular Unconformity, Sargur-Dharwar Relationship, Geochemistry, Geochronology, Kamataka.- International Field Workshop and Seminar on Composition and Evolution of High-Grade Gneiss Terrains
Abstract Views :183 |
PDF Views:132
Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore 560001, IN
2 Geological Survey of India (AMSE), Bangalore 560001, IN
1 Department of Geology, Bangalore University, Bangalore 560001, IN
2 Geological Survey of India (AMSE), Bangalore 560001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 38, No 6 (1991), Pagination: 639-643Abstract
No Abstract.Full Text
- Crustal Section of Peninsular Gneiss - Gondwana - Eastern Ghats, India. (IGCP - 288, Field Workshop 1994)
Abstract Views :186 |
PDF Views:129
Authors
Affiliations
1 Dept. of Geology, Bangalore University, Bangalore - 560 056, IN
1 Dept. of Geology, Bangalore University, Bangalore - 560 056, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 44, No 1 (1994), Pagination: 110-110Abstract
No Abstract.Full Text
- Archaean High-Grade Gneiss Complex from Satnur-Halagur-Sivasamudram Areas, Karnataka, Southern India: Petrogenesis and Crustal Evolution
Abstract Views :223 |
PDF Views:4
Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore - 560 056, IN
2 Laboratoire de Geochimie Isotopique et Geochronologie, Geosciences Rennes-CNRS, 35042 Rennes Cedex, FR
1 Department of Geology, Bangalore University, Bangalore - 560 056, IN
2 Laboratoire de Geochimie Isotopique et Geochronologie, Geosciences Rennes-CNRS, 35042 Rennes Cedex, FR
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 45, No 1 (1995), Pagination: 33-49Abstract
The high-grade gneiss complex of the Satnur-Halagur-Sivasamudram area in southern Karnataka forms a part of amphibolite-granulite facies transition zone of southern India. The major lithologies are metasediments (quartzites-pelites-BIF-Mn-horizons), amphibolite facies gneisses, foliated charnockites, mafic granulites, granite sheets (Closepet-type). All these lithologies show a prominent N-S fabric which appears to have been produced during late Archaean shear deformation. Rb-Srwhole rock isochron and U-Pb zircon and monazite ages suggest that much of the crust accreted during 2.96 Ga magmatic event followed by the 2.5 Ga granulite facies metamorphism; the occurrence of a previous high-grade metamorphism close to 2.9 Ga remains debatable.Both gneisses and foliated charnockites show similar chemical characteristics except in LIL elements, which appear to have been disturbed during granulite metamorphism. Low Mg# (0.18-0.27), low content of HFS elements (Ti, Nb, Ta, Hf and Y) and strongly fractionated REE patterns with HREE depletion suggest that magmatic history of the gneisses and charnockites are similar to the classical Archaean trondhjemite, tonalite, granodiorite suites (TTG).
The geodynamic evolution of the Satnur-Halagur-Sivasamudram area implies a change in the thermal structure and melting conditions of lithosphere from 3.0 to 2.5 Ga. Following the model of Martin (1987), the magmatic protoliths of gneisses and charnockites could have been generated in an accretion zone (subduction-mantle plume ?)2.9 Ga ago, where young oceanic crust melted before dehydration. Granulite facies metamorphism occurred during latest Archaean: synchronous mantle derived melts tapped into mid-crustal levels along a major shear-zone where they induced migmatization (Closepet-type batholith; Jayananda et al. 1994) immediately followed by granulite metamorphism, related to a possible 2.5 Ga old mega-plume (Peucat et al. 1993b).
Keywords
Petrology, Granulites, Archaean, Southern Karnataka.- Rubidium-Strontium Whole-Rock Ages of Banded and Incipient Charnockites from Southern Karnataka
Abstract Views :225 |
PDF Views:3
Authors
Affiliations
1 Department of Geology, Hope College, Holland, MI 49422-9000, US
2 Program in Geosciences, The University of Texas at Dallas, P.O. Box 830688, Richardsoni TX 750083-0688, US
3 Department of Studies in Geology, Kamataka University, Dharwad 580 003, IN
4 Department of Geology, Bangalore University, Jnana Bharathi, Bangalore 560 056, IN
1 Department of Geology, Hope College, Holland, MI 49422-9000, US
2 Program in Geosciences, The University of Texas at Dallas, P.O. Box 830688, Richardsoni TX 750083-0688, US
3 Department of Studies in Geology, Kamataka University, Dharwad 580 003, IN
4 Department of Geology, Bangalore University, Jnana Bharathi, Bangalore 560 056, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 50, No 3 (1997), Pagination: 267-275Abstract
The Late Archaean regional amphibolite facies to granulite facies progression in southern Karnataka contains two textural varieties of charnockite (orthopyroxene-bearing quartzofeldspathic rocks). Banded chamockites typified by the banded pyroxene gneisses in the vicinity of Halaguru are thought to be older than the "incipient" coarse-grained charnockitic alteration of am.phibolite facies gneisses, as at Kabbaldurga, and similar alteration of the banded charnockites in many places south of there.Whole-rock Rb-Sr isochrons were obtained for banded chamockites from the Chillapura quarry near Halaguru, and for incipient charnockite in amphibolite facies gneiss from a quarry near Honganuru, just east of Chamarajnagar. Large multi-layered samples and individual layers (light versus dark layers) were analysed separately in an attempt to discriminate older and younger metamorphic ages. For both quarries, all data yielded good isochrons with ages near 2.5 Ga, or terminal Archaean (2.50 ± 0.05 Ga with initial 87Sr/86Sr = 0.70500 ± 0.00009 for Chillapura and 2.54 ± 0.17 Ga, 0.7088 ± 0.0016 for Honganuru). More than one age of charnockitic metamorphism based on isotope systematics of samples collected from single quarries is not evident.
The high initial Sr ratios for both localities suggest, however, that the country rocks in southern Kamataka had a protracted crustal history prior to 2.5 Ga ago. Moreover, when the mean isotopic data of both quarries are plotted on the same diagram, "a regional isochron" close to 3.0 Ga with low initial Sr ratio results. This plausibly corresponds to a crustal accretion age, in accord with the interpretaiton of previous whole-rock isotope studies of this region based on combining data from widely-separated quarries. A widespread high-grade metamorphic event coinciding with, or following shortly after, crustal accretion remains an open possibility.
- Developments in Metamorphic Petrology
Abstract Views :212 |
PDF Views:124
Authors
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 72, No 4 (2008), Pagination: 443-446Abstract
No Abstract.Full Text
- From the Roots to the Roof of a Granite: the Closepet Granite of South India
Abstract Views :179 |
PDF Views:2
Authors
Jean-Francois Moyen
1,
Jayananda Mudlappa
2,
Anne Nedelec
3,
Herve Martin
1,
B. Mahabaleswar
2,
Bernard Auvray
4
Affiliations
1 Laboratoire Magmas et Volcans, OPGC - Universite Blaise Pascal & CNRS; 5, rue Kessler, 63038, Clermont-Ferrand Cedex, FR
2 Bangalore University, Bangalore - 560 056, Karnataka, IN
3 L.M.T.G., UMR 5563 - University Paul Sabatier & CNRS, 38 rue des 36-Ponts 3 1400 Toulouse, FR
4 Geosciences Rennes Av. du General Leclerc 35042 Rennes cedex, FR
1 Laboratoire Magmas et Volcans, OPGC - Universite Blaise Pascal & CNRS; 5, rue Kessler, 63038, Clermont-Ferrand Cedex, FR
2 Bangalore University, Bangalore - 560 056, Karnataka, IN
3 L.M.T.G., UMR 5563 - University Paul Sabatier & CNRS, 38 rue des 36-Ponts 3 1400 Toulouse, FR
4 Geosciences Rennes Av. du General Leclerc 35042 Rennes cedex, FR
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 62, No 6 (2003), Pagination: 753-768Abstract
The Dharwar craton exposes a natural cross-section of the continental crust. This crust has been intruded during the Late Archaean by a large volume of granites. One of these is the Closepet Granite, which outcrops at different structural levels from deep (corresponding to palaeopressures of 7-8 Kbar) to shallow (2-3 Kbar) crust. This crosssection allows the study of all components of this granite: the ischolar_main zone, displaying strong crust-mantle interaction, resulting in highly heterogeneous, enclave-rich monzonilic to granitic magmas; the transfer zone, with inferred upward movement of these magmas; and a rheological interface in the shallow crust at which the ascent of the magmas was arrested. At this level, only the less viscous (differenciated and enclave-free) magmas were able to rise through a network of dykes and fill small pockets, forming typical, elliptic granitic intrusions (the "intrusion zone").Keywords
Granite Provinces, Structural Levels, Granite Emplacement, Syn-Tectonic Granite, Closepet Granite, Karnataka.- Charnockites and Granulite Facies Rocks
Abstract Views :160 |
PDF Views:127
Authors
Affiliations
1 Department of Geology, Bangalore University, Bangalore, IN
1 Department of Geology, Bangalore University, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 57, No 1 (2001), Pagination: 98-99Abstract
No Abstract.Full Text
- V. S. Upadhyay
Abstract Views :186 |
PDF Views:108
Authors
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 71, No 1 (2008), Pagination: 150-150Abstract
No Abstract.Full Text
- Landmark Papers in Volcanic Petrology
Abstract Views :168 |
PDF Views:117
Authors
Affiliations
1 Bangalore, IN
1 Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 73, No 2 (2009), Pagination: 295-296Abstract
No Abstract.Full Text
- Archaean Geology
Abstract Views :163 |
PDF Views:112
Authors
Affiliations
1 Geology Department Bangalore University, Bangalore, IN
1 Geology Department Bangalore University, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 29, No 2 (1987), Pagination: 278-278Abstract
No Abstract.Full Text
- Proceedings of the National Seminar Commemorating Dr. M.S. Krishnan Birth Centenary
Abstract Views :183 |
PDF Views:135
Authors
Affiliations
1 Department of Geology, Bangalore University, IN
1 Department of Geology, Bangalore University, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 60, No 5 (2002), Pagination: 605-606Abstract
No Abstract.Full Text
- Geochemical Behaviour of Vanadium, Chromium, Cobalt, Nickel, and Copper during Progressive Chloritization of Biotites in Granites
Abstract Views :998 |
PDF Views:4
Authors
Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Government of India, 1-10-153-156, Begumpet, Hyderabad – 500 016, IN
2 Department of Geology, Bangalore University, Bangalore, IN
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Government of India, 1-10-153-156, Begumpet, Hyderabad – 500 016, IN
2 Department of Geology, Bangalore University, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 80, No 3 (2012), Pagination: 301-303Abstract
Evaluation of the vanadium, chromium, cobalt, nickel, and copper contents of five biotites, chloritized to varying degrees, from a magmatic granitic series of the 2700-million-year-old Giants Range Batholith of Northeastern Minnesota, USA, on the southern margin of the Canadian Shield, determined by wavelength-dispersive x-ray fluorescence spectrometry, shows that, during progressive chloritization of biotites in granites, the content of vanadium decreases and the contents of chromium, cobalt, nickel, and copper increase. The results emphasise the need for great caution when interpreting whole-rock trace-element data in petrological research.Keywords
Granitic Biotites, Chloritization, Vanadium, Chromium, Cobalt, Nickel, Copper, Geochemical Behaviour, Giants Range Batholith, Minnesota, USA.References
- CHAYES, F. (1955) Potash feldspar as a by-product of the biotite-chlorite transformation. Jour. Geol., v. 63, pp. 75-82.
- FLANAGAN, F.J. (1969) U.S. Geological Survey Standards-II. First compilation of data for the new U.S.G.S. rocks. Geochim. Cosmochim. Acta, v. 33, pp. 81-120.
- FLANAGAN, F.J. (1973) 1972 values for International geochemical reference sample. Geochim. Cosmochim. Acta, v. 37, pp. 1189-1200.
- PHINNEY, W.C. (1963) Phase equilibria in the metamorphic rocks of St. Paul Island and Cape North, Nova Scotia. Jour. Petrol., v. 4, pp. 90-130.
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- The Abundances of Some Trace-Elements in the First-Ever Reported Sample of Spinifex-Textured Komatiite from Ghatti Hosahalli, Karnataka
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Authors
Affiliations
1 "Manipallavam", 29, Balakrishna Road, Valmiki Nagar, Thiruvanmiyur, Chennai - 600 041, IN
2 Department of Geology, Bangalore University, Bangalore - 560 056, IN
3 Flat B-203, Block-B, United Avenue Apartments, South End, 7-1-29, Ameerpet, Hyderabad - 500 016, IN
1 "Manipallavam", 29, Balakrishna Road, Valmiki Nagar, Thiruvanmiyur, Chennai - 600 041, IN
2 Department of Geology, Bangalore University, Bangalore - 560 056, IN
3 Flat B-203, Block-B, United Avenue Apartments, South End, 7-1-29, Ameerpet, Hyderabad - 500 016, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 79, No 4 (2012), Pagination: 361-366Abstract
The paper reports wavelength-dispersive x-ray fluorescence spectrometric data on the abundances of Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in the first-ever reported sample of spinifex-textured komatiite from India at Ghatti Hosahalli in Karnataka. With some exceptions, these abundances are similar to those reported for the spinifex-textured komatiite from the Barberton greenstone belt in South Africa. The values for some alteration-resistant element ratios - Ti/Zr, Ti/Y, Ti/Sc, Ti/V, Zr/Y, Zr/Sc, Sc/Y, V/Zr, and V/Sc - for chondrite and for spinifex-textured komatiites from Ghatti Hosahalli (India), Barberton (South Africa), Munro (Canada), and Yilgarn (Australia) reveal that, except for the Ti/Zr ratio for the Ghatti Hosahalli komatiite, the other ratios from the four terrains define a unique trend that is almost superimposed on the trend defined by these ratios for chondrite. This suggests that the processes of formation of komatiitic lavas from the four far-separated terrains were similar, and that, the source regions from which these lavas formed had a chondritic composition.Keywords
Komatiite, Trace-Elements, Ghatti Hosahalli, Karnataka, India, Barberton, Munro, Yilgarn.References
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