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Raghu Nandan, K. R.
- A Note on the Petrology of Apatite-Biotite-Monchiquite from Giridih Coalfield, Bihar
Authors
1 Indian School of Mines and Applied Geology, Dhanbad, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 2, No 0 (1961), Pagination: 39-45Abstract
A re-examination of Holland's collection of mica peridotites from Giridih coalfield is presented with a detailed petrographic description of the rocks which entitles them to be specifically termed as 'apatite-biotite-monchiquites', recorded as such for the first time from the Lower Gondwana coalfields of India.
The order and periods of crystallisation of the constituent minerals are given in a graphical form by plotting the modal analysis to discuss the petrogenesis. The authors consider that the first genetic class of minerals, viz. olivine and augite crystallised and accumulated at place before the emplacement of the magma into the country rock. After emplacement, the minerals of the second genetic class, viz. apatite, biotite and perovskite formed either from the condensation of a volatile phase or hydrous environment with quick lowering of temperature. With the abrupt termination of favourable temperature conditions, the last remnants of the liquid froze into interstitial glass, most of which soon devitrified into analcite.
- Silver Mineralisation in Ingaldhal Copper Deposit, Chitradurga Greenstone Belt, Karnataka
Authors
1 Geological Survey of India, Bangalore, IN
2 Geological Survey of India, Jaipur, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 36, No 6 (1990), Pagination: 607-623Abstract
Native silver alloyed with gold in varying proportions occurs as tiny inclusions mostly in the sulphide ores of Ingaldhal, Chitradurga schist belt. The data presented establishes the copper deposit as a source of silver metal too and the appropriateness of terming the hill 'Belligudda' (Silver Hill) by the ancient miners is affirmed. The volcanic flows having a dominant tholeiitic character are the actual source of basemetals, as well as precious metals, while tectonism and metamorphism aided by the intrusion of Chitradurga granite pluton have probably caused variable amounts of redistribution and remobilisation.Keywords
Copper, Silver, Gold, Polymetallic Sulphides, Ingaldhal, Chitradurga Schist Belt, Karnataka.- Construction and Display of Geoscientific Maps Derived from Databases
Authors
1 Geological Survey of India, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 34, No 4 (1989), Pagination: 440-441Abstract
No Abstract.Full Text
- Platinum-group Element Exploration 'Developments in 'Economic Geology'
Authors
1 Geological Survey of India, Operations Karnataka and Goa Unit, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 36, No 5 (1990), Pagination: 550-551Abstract
No Abstract.Full Text
- Gold Metallogeny and Exploration
Authors
1 Operations Karnataka and Goa Unit, Geological Survey of India, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 38, No 1 (1991), Pagination: 102-104Abstract
No Abstract.Full Text
- Geological Setting and Exploration of the Platinum Group Elements
Authors
1 Geological Survey of India, Operations Karnataka and Goa, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 38, No 6 (1991), Pagination: 637-639Abstract
No Abstract.Full Text
- Book Review
Authors
1 Geological Survey of India, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 39, No 4 (1992), Pagination: 356-356Abstract
No Abstract.Full Text
- ISME-AI '90, Special Issue on Mineral Exploration - The Use of Artificial Intelligence, 'Geoinformatics'
Authors
1 Geological Survey of India, Operations Karnataka & Goa, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 40, No 1 (1992), Pagination: 91-92Abstract
No Abstract.Full Text
- Exploration With a Computer Geoscience Data Analysis Applications
Authors
1 Geological Survey of India, Operations Karnataka & Goa, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 40, No 1 (1992), Pagination: 92-92Abstract
No Abstract.Full Text
- Titanium Mineral Deposits
Authors
1 Geological Survey of India, Karnataka and Goa, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 40, No 3 (1992), Pagination: 300-300Abstract
No Abstract.Full Text
- Granite Associated Gold and Base Metal Deposits
Authors
1 Geological Survey of India, AMSE Wing, Bangalore-560 001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 43, No 6 (1994), Pagination: 715-715Abstract
No Abstract.Full Text
- Spinifex-Textured Peridotitic Komatiite from Honnabetta Area, Nagamangala schist Belt, Karnataka
Authors
1 Operations Karnataka and Goa, IN
2 Geological Survey of India, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 44, No 5 (1994), Pagination: 483-493Abstract
Metaultramafite exposure in the newly cut Hemavathi canal section in Honnnbetta area in the Nagamangala belt exhibits excellent spinifex texture with komaliitic chemistry implying their volcanic origin. Though, several such localities of spinifex textured peridotitic komaliitcs (STPKs) have already been recorded from Ghattihosahalli, Kummanghatta, Banasandra, Mayasandra and Karighatta areas, this new find of plate and random spinifex textured ultmmafic variant from Honnabetta is the first report from the Nagamangala belt. They show yellowish green colour with skeletal forms of olivine blades, which are totally altered to talc-tremolite-chlorite, anthophyllite, iddingsite and antigorite. Parallel sheafs and aggregates of bladed olivine pseudomorphs form plate spinifex with criss crossing random orientation pattern. The primary igneous mineralogy consists of altered relict olivine and clinopyroxene phenocrysts. A few samples exhibit micro-spinifex texture with randomly oriented, elongated platy, pseudomorphs of olivine separated by tremolite in the groundmass. Gradational change from fine to coarse-grained spinifex with long crystals (rare) of clinopyroxene in a fine-gained groundmass of tremolite and chloriteis also observed. Medium-grained spinifex rockshow crystals upto 5 to 2 mm thick and 10 to 50 mm long in sheafs with parallel grouping and abut against each other randomly at angles varying from 40 to 60° enclosing triangular to rectangular interstitial talc, chforitc, pale green finegrained chlorite and glassy material. Ilmenite-magnetite and chrornite are the important accessory opaque minerals, with ilrnenite at places showing oriented picotite inclusions. Normative plots indicate that the STPKs of Honnabetta are hurzburgitic peridotites.
Compared to the Ghattihosahalli-Kummanghatta and Banasandra STPKs, tlonnabella STPKs show characteristic plate and random spinifex texture. In texture they are similar to Karighatta STPKs and in composition they compare well with Mayasandra STPKs with their low CaO:Al2O3 ratios. lnspite of alteration (hydration), deformation and metamorphism, preservation of primary igneous structures and textures is almost perfect in Honnabetta. Such a zone with a possible thermal erosion model for the Komatiitic types imply some sulphide bodies at depth, as incidence of sulphide associated with gold minerrrlisation arc observed in Honnabetta area.
Keywords
Spinifex Texture, Komatiite, Petrology, Nagamangala, Honnabetta, Karnataka.- Project 'Vasundhara'
Authors
1 AMSE Wing, Geologicnl Survey of India, Bangalore - 560 001, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 45, No 1 (1995), Pagination: 111-114Abstract
No Abstract.Full Text
- PGE Exploration Guidelines and Required Laboratory Inputs
Authors
1 787, 7th Cross, M. C. Layout, Vijayanagar, Bangalore - 560 040, IN
2 AMSE, GSI, Jayanagar, Bangalore-560 011, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 46, No 3 (1995), Pagination: 324-329Abstract
No Abstract.Full Text
- Chronique De La Recherche Miniere, BRGM, France
Authors
1 Operations Karnataka and Goa Unit, Geological Survey of India, Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 35, No 4 (1990), Pagination: 435-435Abstract
No Abstract.Full Text
- The Indian Gold Scene
Authors
1 "Venkatadri" 787, 7th Cross, MC Layout Vijayanagar, Bangalore - 560 050, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 48, No 5 (1996), Pagination: 596-597Abstract
No Abstract.Full Text
- Have We Not Neglected an Important Source of Gold?
Authors
1 Bangalore - 560 040, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 50, No 6 (1997), Pagination: 795-795Abstract
No Abstract.Full Text
- The Satpura Uplift and the Palaeoclimate of the Holocene and Auxiliary Evidence from the Valmiki Ramayana
Authors
1 409, S.Lexington Ave, White Plains, NY - 10606, US
2 "Venkatadri", 787, 7th Cross, M C Layout, Vijayanagar, Bangalore - 560 040, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 66, No 2 (2005), Pagination: 161-170Abstract
The available geological, floral and faunal evidences support the existence of a very cold climate in the Peninsular India during the Pleistocene. Against this background, the middle to late Holocene event of a snowy winter at Panchavati described in the Valmiki Ramayana has been analysed.
The geological evaluation of the existing information indicates a 300 m epeirogenic uplift of the Satpura range and the adjacent areas, during the upper Pleistocene, followed by about 1000 m of orogenic uplift of the Satpura crustal block, bounded by the seismogenic, Moho-Reaching, Narmada and Tapti graben-Faults that were reactivated in the Holocene, as proved by recent geological mapping and geothermal drilling. The uplift may have taken place, either, by sudden displacements, or, by slow, tectonic creep, or, by a combination of both the processes, thereby raising the height of a pre-Existing Satpura range. This probably blocked partly, the route of very cold, arctic type of air-Flows descending from the Himalayan glaciers that had then reached lower elevations of 1000 to 1500 m and, interacting with the moist winds blowing eastwards from the Arabian Sea, thereby giving rise to the snowfall at Panchavati.
The warming up phase of the Quaternary commenced at the end of the Pleistocene glaciation. This continued up to the commencement of the late Holocene, and also caused the gradual recession of the of the snouts of the Himalayan glaciers to higher elevations. This resulted in the cessation of the arctic type of winds coming down to the Peninsula from the Himalayas, thus terminating the snowy winters prevalent earlier.
The astronomical method of dating the Ramayana gives the most probable age of the epic as 2000B.C. and the less probable age of 4000B.C., by traditional (historical and genealogical) methods of dating. The range of the above two ages tallies with the geologically deduced range of age of middle to late Holocene for the palaeoclimatic events described in the Panchavati area. It is suggested that the palaeoclimatic and other environmental changes of the Quaternary period in the Sonata area of the Peninsula be subjected to detailed studies in the future.
Keywords
Palaeoclimate, Satpura Uplift, Epeirogeny, Ramayana, Snowy Winter, Holocene, Pleistocene, Quaternary, Narmada-Tapti Faults, Central India.- Gold Prospecting and Small-Scale Mining
Authors
1 Venkatadri, 787, 7th Cross, M C Layout, Vijayanagar, Bangalore -560 040, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 63, No 1 (2004), Pagination: 116-117Abstract
No Abstract.Full Text
- Mineral Resources Management and the Environment
Authors
1 "Venkatadn 787 7" Cross M C Layout Vijayanagar Bangalore -560040, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 63, No 3 (2004), Pagination: 358-359Abstract
No Abstract.Full Text
- Mining Geological Knowledge from Ancient Sanskrit Texts
Authors
1 Venkatadri, 787, MC Layout Vijaynagar, Bangalore 560 040, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 63, No 2 (2004), Pagination: 238-238Abstract
No Abstract.Full Text
- Minerals Of the Indian System of Medicine - Ayurveda and Siddha (Bharatiya Rasashastra
Authors
1 Venkatadri, 787, 7thCross M. C.layout, Vijayanagar Bangalore - 560 040, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 63, No 4 (2004), Pagination: 466-467Abstract
No Abstract.Full Text
- The Study of Meteoritic and Cometary Impacts on Earth
Authors
1 Bangalore, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 66, No 6 (2005), Pagination: 772-772Abstract
No Abstract.Full Text
- Gold Mineralisation in the Palaeoproterozoic Rocks of Sanjela-Manpur-Dugocha Belt, Salumber Area, Udaipur District, Rajasthan
Authors
1 787, 7th Cross, M.C. Layout, Viyayanagar, Bangalore - 560 040, IN
2 AMSE Wing, Geological Survey of India, WZ, Jaipur - 302 004, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 62, No 1 (2003), Pagination: 123-124Abstract
No Abstract.Full Text