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Gold-bearing rocks of Mangalur greenstone belt, Gulbarga District, Karnataka

  • S. G. Tenginkai
  • A. G. Ugarkar
Article
  • 37 Downloads

Abstract

The Mangalur greenstone belt of Dharwar Craton, South India, is an Archaean schist belt dominated by metavolcanic rocks. The gold mineralization occurs within the metavolcanics and the fabric, mineralogy and geochemistry of these host rocks indicate that they were tholeiitic basalts regionally metamorphosed under medium to low-grade greenschist facies. The basic metavolcanic rocks occur as tholeiitic metabasalts and amphibolites. The rocks have undergone some fractionation and appear to be derived from melts generated by 10 to 25% melting of the mantle at depths 30 to 35 km around temperature 1200°C and pressure 12 kb. The source of gold is mainly in the basalts and not in the surrounding granites.

Keywords

Gold-quartz veins metavolcanic rocks tholeiites geochemistry petrogenesis Mangalur greenstone belt 

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References

  1. Ananta Iyer G V and Vasudev V N 1979 Geochemistry of the Archaean metavolcanics of Kolar and Hutti Gold Fields, Karnataka, India;J. Geol. Soc. India 20 419–432Google Scholar
  2. Anhauesser C R, Fritz K, Fyfe W S and Gill R C O 1975 Gold in primitive Archaean volcanics;Chem. Geol. 16 129–135CrossRefGoogle Scholar
  3. Bernasconi A 1985 Archaean gold mineralization in Central Eastern Brazil: a review;Miner. Deposita 20 277–283CrossRefGoogle Scholar
  4. Boyle R W 1961 The geology, geochemistry and origin of the gold deposits of the Yellowknife district;Geol. Surv. Can. Mem. 310 1–193Google Scholar
  5. Boyle R W 1979 The geochemistry of gold and its deposits;Geol. Surv. Can. Bull. 280 584Google Scholar
  6. Bruce Foote R 1875 Geology of Southern Maharatta country;Geol. Soc. India Mem. XII pt. 1Google Scholar
  7. Condie K C 1976Plate tectonics and crustal evolution; (New York: Pergamon Press) 145–168Google Scholar
  8. Condie K C 1981 Archaean greenstone belts;Developments in Precambrian geology (Amsterdam: Elsevier) vol. 3, pp. 1–434Google Scholar
  9. Deer W A, Howie R A and Zussman J 1962Rock-forming minerals (London: Longman) vol. 5 pp. 1–371Google Scholar
  10. Ewart A 1981 Petrochemical aspects of the tertiary anorogenic volcanism of Southern and Central Queensland, Australia. In:Deccan volcanism and related basalt provinces in other parts of the world (eds) K V Subba Rao and R N SukheswalaGeol. Soc. India Mem. 3 377–393Google Scholar
  11. Flanagan F J 1973 Values for international geochemical reference samples;Geochim. Cosmochim. Acta. 37 1189–1200CrossRefGoogle Scholar
  12. Ford C E, Russel D G, Craven J A and Fisk M R 1983 Olivine-liquid equilibria: temperature, pressure and composition dependence of the crystal/liquid partition coefficients for Mg, Fe2+, Ca and Mn;J. Petrol. 24 256–265Google Scholar
  13. Fryer B J, Kerricn R, Hutchinson R W, Peirce M G and Rogers D S 1979 Archaean precious-metal hydrothermal system, Dome Mine, Abitibi Greenstone Belt. I. Patterns of alteration and metal distribution;Can. J. Earth Sci. 16 421–439Google Scholar
  14. Fyfe W S and Kerrich R 1984 Gold: Natural concentration processes. InGold 82; The geology, geochemistry and genesis of gold deposits (ed) R P ForsterGeol. Soc. Zimbabwe Sp. Pub. 1 (Rotterdam: Balkema) 99–127Google Scholar
  15. Glikson A Y 1983 Geochemistry of Archaean tholeiitic basalt and High-Mg to peridotite komatiite suites, with petrogenetic implications inPrecambrians of South India (eds) S M Naqvi and J J W Rogers;Geol. Soc. India Mem. 4 183–219Google Scholar
  16. Hanson G N and Langmuir C H 1978 Modelling of major elements in mantle-melt systems using trace element approaches;Geochim. Cosmochim. Acta. 42 725–741CrossRefGoogle Scholar
  17. Hutchinson R W 1976 Lode gold deposits: the case for volcanogenic derivation;Proc. Pacific Northwest Mining and Metals Conference, Portland, Oregon (Oregon Dept. of Geology and Mineral Industries) pp. 64–105Google Scholar
  18. Keays R R and Scott R B 1976 Precious metals in ocean-ridge basalts: implications for basalts as source rocks for gold mineralization;Econ. Geol. 71 705–720Google Scholar
  19. Kerrich R and Fryer B J 1981 The separation of rare elements from abundant base metals in Archaean lode gold deposits: implications of low water/rock source regions;Econ. Geol. 76 160–166Google Scholar
  20. Kerrich R and Fyfe W S 1981 The gold-carbonate association: source of CO2 and CO2-fixation reactions in Archaean lode deposits;Chem. Geol. 33 265–294CrossRefGoogle Scholar
  21. Kwong Y T G and Crocket J H 1978 Background and anomalous gold in rocks of an Archaean greenstone assemblage, Kakagi Lake area, Northwestern Ontario;Econ. Geol. 73 50–63Google Scholar
  22. Langmuir C H and Hanson G N 1980 An evaluation of major element heterogeneity in the mantle sources of basalts;Philos. Trans. R. Soc. London A297 383–407Google Scholar
  23. Mahadevan C 1945 Sedimentary structures in Mangalur band of Dharwars;J. Hyderabad Geol. Surv. 4 31–36Google Scholar
  24. Mahadevan C and Krishnamurthy L S 1945 Löllingite in pegmatite in the Mangalur band of Dharwars;J. Hyderabad Geol. Surv. 4 18–21Google Scholar
  25. Meyer M and Saager R 1985 The gold content of some Archaean rocks and their possible relationship to epigenetic gold-quartz vein deposits;Miner. Deposita 20 284–289CrossRefGoogle Scholar
  26. Naqvi S M, Divakara Rao V, Satyanarayana K and Hussain S M 1974 Geochemistry of post-Dharwar basic dykes and the Precambrian crustal evolution of Peninsular India;Geol. Mag. 11 229–236Google Scholar
  27. Phillips N G 1986 Geology and alteration in the Golden Mile, Kalgoorlie;Econ. Geol. 81 779–808Google Scholar
  28. Radhakrishna B P 1983 Archaean granite-greenstone terrain of the South Indian Shield inPrecambrians of South India (eds) S M Naqvi and J J W RogersGeol. Soc. India Mem. 4 1–46Google Scholar
  29. Rajamani V, Shivakumar K, Hanson G N and Shirey S B 1985 Geochemistry and petrogenesis of amphibolities, Kolar schist belt, South India: evidence for komatiitic magma derived by low percentages of melting of the mantle;J. Petrol. 26 92–123Google Scholar
  30. Ramachandra Rao M N 1980 Mangalur Gold Prospect — A case study review;Proc. Seminar on recent trends in gold mining practice, India pp. 1–6Google Scholar
  31. Ringwood A E 1975Composition and petrology of the earth’s mantle (New York: McGraw-Hill) p. 618Google Scholar
  32. Saager R and Meyer M 1984 Gold distribution in Archaean granitoids and supracrustal rocks from Southern Africa: a comparison inGold 82; The geology, geochemistry and genesis of gold deposits (ed) R P ForsterGeol. Soc. Zimbabwe Sp. Pub. 1 (Rotterdam: Balkema) pp. 53–70Google Scholar
  33. Saager R, Meyer M and Muff R 1982 Gold distribution in supracrustal rocks from Archaean greenstone belts of South Africa and from palaeozoic ultramafic complexes of the European Alps: metallogenic and geochemical implications;Econ. Geol. 77 1–24Google Scholar
  34. Schuler V C O 1971 Chemical analysis and sample preparation; Inmodern methods of geochemical analysis (eds) R E Wairnerdi and E A Uken (New York: Plenum Press) p. 66Google Scholar
  35. Sugimura A 1968 Spatial relations of basaltic magmas in island arcs;Basalts-Poldervaart treatise on rocks of basaltic composition (New York: Interscience) pp. 537–572Google Scholar
  36. Taylor S R and Mc Lennan S M 1981 The composition and evolution of the continental crust: rare earth element evidence from sedimentary rocks;Philos. Trans. R. Soc. London A301 381–399CrossRefGoogle Scholar
  37. Ugarkar A G 1986 Mineralogy and geochemistry of sulphide-gold-quartz veins and gold bearing metavolcanics of Mangalur greenstone belt, Gulbarga district, Karnataka;Ph.D. Thesis, Karnatak University, Dharwad Google Scholar
  38. Vasudev V N 1980 Geology and geochemistry and mineralization in the greenstone belts of Hutti and Chitradurga, Karnataka;Indian Natl. Sci. Acad. Lectures pp. 28–36Google Scholar
  39. Viljoen M J and Viljoen R P 1969 Geology and geochemistry of the lower ultramafic unit of the Onverwacht group and a proposed new class of igneous rocks;Spec. Pub. Geol. Soc. S. Africa 2 55–86Google Scholar
  40. Wanless R K, Boyle R W and Lowden J A 1960 Sulfur isotope investigation of the gold-quartz deposits of the Yellowknife district;Econ. Geol. 55 1591–1621CrossRefGoogle Scholar
  41. Wilkinson J F G 1981 Continental and mid-ocean ridge tholeiites: some similarities and contrasts inDeccan volcanism and related basalt provinces in other parts of the world; (eds) K V Subba Rao and R N SukheswalaGeol. Soc. India Mem. 3 340–361Google Scholar

Copyright information

© Indian Academy of Sciences 1987

Authors and Affiliations

  • S. G. Tenginkai
    • 1
  • A. G. Ugarkar
    • 1
  1. 1.Department of Studies in GeologyKarnatak UniversityDharwadIndia

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