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Safonov, Yu. G.
- Study of Lead Isotopes for Investigating the Origin of Endogenic Deposits with Special Reference to Some Ore Deposits from India
Authors
1 Institute of Geology of Ore Deposits (IGEM) Academy of Sciences, 35, Staromonetnii Street, Moscow, USSR, RU
2 Chitradurga Copper Co., IN
3 Mineralogical Inst., University of Mysore, Manasa Gangotri, Mysore 6, IN
4 Dept. of Geology, University of Delhi, Delhi 7, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 21, No 3 (1980), Pagination: 107-116Abstract
The isotope composition of leads from ore deposits in general reflects the age of ore mineralisation and its genetical features. Two examples have been given to illustrate a direct connection of ore lead isotope composition with the source ore. Calculations of the model age from lead isotope data form the basis for genetic reconstructions of Precambrian deposits. Radical improvement in the accuracy of mass spectrometric isotope lead analysis has made possible the employment of two-stage and in some cases more complicated models for genetic reconstructions. The Penehanga Bay lead-zinc deposit and gold-silver deposits of South Dakota have been studied using high accuracy mass spectrometer. Both the deposits show that ore formation took place one to two billion years after craton formation, and lead present in ores originated at least from two different Sources.
Keeping this background of experience, fifteen galena samples from five sulphide and gold-sulphide deposits of the Indian Shield have been selected and determination of lead isotope composition has been carried out by the Soviet authors in the USSR using recently developed M.I.1320 Mass Spectrometer. The isotopic ratios of galena from Ingaldhal copper deposit are the most primitive among the analysed ores of the Indian Shield. The results of lead isotopic determination have been interpreted in terms of the general theory of 'plumbotectonics '.
- Mineralogical and Geochemical Features of Endogene Gold and Copper Deposits of South India
Authors
1 Institute of Geology of ore deposits (IGEM), Academy of Sciences, 35, Staromonetnii Street, Moscow, RU
2 Geological Society of India, Bangalore 560053, IN
3 Department of Geology, University of Mysore, Manasagangotri, Mysore 570005, IN
4 Department of Mines & Geology, Bangalore 560001, IN
5 Hutti Gold Mines, Raichur District, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 21, No 8 (1980), Pagination: 365-378Abstract
No Abstract.- Genetic features of Gold Ore Deposit at Kolar, Dharwar Craton, India
Authors
1 Institute of Geology of Ore Deposits, Academy of Science USSR, Moscow, RU
2 Department of Mines of Geology, Bangalore 560001, IN
3 Department of Geology, University of Mysore, Mysore 570005, IN
4 Indian Institute of Science, Bangalore 560012, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 25, No 3 (1984), Pagination: 145-154Abstract
Twenty-five ore minerals have been identified from a study of ore-bearing samples from different reefs of the Kolar Goldfields. The mineral association includes fifteen minerals being reported for the first time: altaite, hessite hedleyite, tzumoite, volynskyite gudmundite, ullmannite, brethauptite, tetrahedrite, hawleyite, cotunite, electrum and native bismuth. Besides, two new minerals, as yet unnamed, have been determined through electronprobe - Pb3Te9Cl4S2 and PbTeCI2 They occur along with cotunite (PbCI2) and altaite.The study of time relations of different ore and vein mineral assemblages in the Kolar gold-quartz reefs has revealed six stages of mineralization: 1) Early quartz, 2) quartz-feldspar (Pegmatite), 3) scheelite, 4) early sulphides with gold, 5) sulphide-gold-tellurides (with quartz) and 6) quartz-carbonate. Fluid inclusions indicate that the mineral association of quartz-feldspar stage has developed under high TP-conditions of 250-300°C and 1.8 and 3.5 kb. Isotope composition of sulphur in the sulphides indicate the juvenile nature of sulphur. Available data suggest that the quartz of first stage is of metasomatic origin, derived possibly from host amphibolites; gold-sulphide and gold-telluride mineralization took place through hydrothermal processes.