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Granitoids around the Malanjkhand copper deposit: Types and age relationship

  • M K Panigrahi
  • A Mookherjee
  • G V C Pantulu
  • K Gopalan
Article
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Abstract

On the basis of field relations, petrography and chemistry, three types of granitoids are recognized at Malanjkhand in and around the copper deposit over an area of about 200 km2. These are (i) a fine grained ‘leucogranite’ of restricted occurrence in the surrounding area (Gr-I); (ii) coarse-grained, grey in most parts, gneissose granitoid of regional extension (Gr-II); and (iii) the pink-feldspar bearing massive type hosting the mineralization with occasional representatives in the surrounding country (Gr-III). Gr-I comes out as a distinct entity on the basis of cross-cutting relation and mineralogical and chemical composition, the Rb-Sr whole rock isochron also giving a younger age than the other two groups irrespective of the regression model used. Gr-II comes out as the oldest unit but its age relationship with Gr-III cannot be established unequivocally. An uncorrelated error regression model establishes the age relationship as Gr-I<Gr-III<Gr-II, whereas a two-error regression model establishes temporal closeness between Gr-II and III.

Keywords

Malanjkhand copper deposit granitoids geochronology isochrons initial ratio temporal relation 

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References

  1. Ague J J and Brimhal G H 1988 Regional variations in bulk chemistry, mineralogy and composition of mafic and accessory minerals in the batholiths of California;Geol. Soc. Am. Bull. 100 891–911CrossRefGoogle Scholar
  2. Barker F and Arth J G 1976 Generation of trondjhemitic—tonalitic liquid and Archean bimodal trondjhemite—basalt suites;Geology 4 596–600CrossRefGoogle Scholar
  3. Bottino M L and Fullagar P D 1968 The effect of weathering on whole rock Rb-Sr ages of granitic rocks;Am. J. Sci. 226 661–670CrossRefGoogle Scholar
  4. Brooks S C, Hart S R and Wendt I 1972 Realistic use of two-error regression treatment as applied to rubidium-strontium data;Rev. Geophys. Space Phys. 10 551–577CrossRefGoogle Scholar
  5. Faure G and Powell J L 1972Strontium isotpoe geology: Monograph Series of Theoretical and Experimental Studies (Heidelberg: Springer Verlag)5 43–54Google Scholar
  6. Gerstenberger H 1989 Autometasomatic Rb enrichments in highly evolved granites causing lowered Rb-Sr isochron intercepts;Earth Planet. Sci. Lett. 93 65–75CrossRefGoogle Scholar
  7. Ghosh P K, Chandy K C, Bishui P K and Prasad R 1986 Rb-Sr age of granite gneiss in Malanjkhand area, Balaghat District, Madhya Pradesh;Indian Ind. Min. 40 1–8Google Scholar
  8. Giggenbach W F 1984 Mass transfer in hydrothermal alteration systems: A conceptual approach;Geochim. Cosmochim. Acta 48 2693–2711CrossRefGoogle Scholar
  9. Hine R, William S I S, Chappel B W and White A J R 1978 Contrasts between I- and S-type granitoids of the Kosiusko batholith;J. Geol. Soc. Aust. 25 219–234Google Scholar
  10. Lutz T M and Srogi L 1986 Biased isochron ages resulting from subsolidus isotope exchange: A theoretical model and results;Chem. Geol. 56 63–71CrossRefGoogle Scholar
  11. McCarthy T S and Cawthorn R G 1980 Changes in initial87Sr/86Sr ratio during protracted fractionation in igneous complexes;J. Petrol. 21 245–264Google Scholar
  12. Narang J L, Sharma R S, Mathur S M and Nath M 1974 Position of the Malanjkhand sulfide mineralization in the tectonic history of India;Geol. Surv. of India Misc. Publ. pp. 113–116Google Scholar
  13. Nath M, Mathur S M, Sharma R S, Neelakantham S and Narang 1973 Geology and mineralization in Malanjkhand area, Balaghat district, MP.Geol. Surv. of India Sp. Publ. No 3, 203–207Google Scholar
  14. Naylor R S, Steiger R H and Wasserburg G J 1970 U-Th-Pb and Rb-Sr systematics in 2700×106 years old plutons from the Southern Wind River Range, Wyoming;Geochim. Cosmochim. Acta 34 1133–1159CrossRefGoogle Scholar
  15. Panigrahi M K 1992Copper-Molybdenum mineralization and associated granitoids at Malanjkhand, MP, India (unpublished) Ph.D. Thesis I.I.T., Kharagpur, pp. 153Google Scholar
  16. Peterman Z E 1979 Strontium isotope geochemistry of Late Archaean to Late Cretaceous tonalites and trondjhemites; In:Trondjhemites, Dacites and Related Rocks (ed.) F Barker (Amsterdam: Elsevier) 275–290Google Scholar
  17. Roddick J C and Compston W 1977 Strontium isotopic equilibration: A solution to a paradox;Earth Planet. Sci. Lett. 34 238–246CrossRefGoogle Scholar
  18. Sarkar A, Sarkar G, Paul D K and Mitra N D 1990 Precambrian geochronology of the Central Indian shield: A review;Proc. Symp. on Precamb. of Central India GSI Nagpur (India), 450–470Google Scholar
  19. Schaltegger U 1990 Post-magmatic resetting of Rb-Sr whole rock ages—A study in the Central Aar granites (Central Alps, Switzerland);Geologische Rundschau 79/3 709–774CrossRefGoogle Scholar
  20. Sikka D B 1989 Malanjkhand: Proterozoic porphyry copper deposit, MP, India;J. Geol. Soc. India 34 487–504Google Scholar
  21. Subba Rao T V, Bhaskar Rao Y J, Sivaraman T V and Gopalan K 1989 Rb-Sr age of Elchuru alkaline complex: Implication to alkaline magmatism in the Eastern Ghat mobile belt. In: Alkaline Rocks, (ed.) C LeelanandamGeol. Soc. India Mem. 15 pp. 207Google Scholar
  22. Tripathy C 1974 The Malanjkhand-Taregaon porphyry copper deposit;Misc. Publ. GSI,34 161–168Google Scholar
  23. Vistelius A B and Faas A V 1991 On the precision of age measurements by Rb-Sr Isochrons in non-trivial cases;Math. Geol. 23 999–1040CrossRefGoogle Scholar
  24. Watson E B and Capobianco C J 1981 Phosphorus and the rare earth elements in felsic magmas: an assessment of the role of apatite;Geochim. Cosmochim. Acta 45 2349–2358CrossRefGoogle Scholar
  25. Wendt I and Carl C 1991 A statistical distribution of the mean squared weighted deviation;Chem. Geol. (Isotope Geosc. Section) 86 275–285CrossRefGoogle Scholar
  26. Williamson J H 1968 Least square fitting of a straight line;Can. J. Phys. 46 1845–1847Google Scholar
  27. York D 1969 Least-square fitting of a straight line with correlated errorsEarth Planet. Sci. Lett. 5 320–324CrossRefGoogle Scholar

Copyright information

© Indian Academy of Sciences 1993

Authors and Affiliations

  • M K Panigrahi
    • 1
  • A Mookherjee
    • 1
  • G V C Pantulu
    • 2
  • K Gopalan
    • 2
  1. 1.Department of Geology and GeophysicsIndian Institute of TechnologyKharagpur
  2. 2.National Geophysical Research InstituteHyderabad

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