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.
Similar content being viewed by others
References
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. 100 891–911
Barker F and Arth J G 1976 Generation of trondjhemitic—tonalitic liquid and Archean bimodal trondjhemite—basalt suites;Geology 4 596–600
Bottino M L and Fullagar P D 1968 The effect of weathering on whole rock Rb-Sr ages of granitic rocks;Am. J. Sci. 226 661–670
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. 10 551–577
Faure G and Powell J L 1972Strontium isotpoe geology: Monograph Series of Theoretical and Experimental Studies (Heidelberg: Springer Verlag)5 43–54
Gerstenberger H 1989 Autometasomatic Rb enrichments in highly evolved granites causing lowered Rb-Sr isochron intercepts;Earth Planet. Sci. Lett. 93 65–75
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 1–8
Giggenbach W F 1984 Mass transfer in hydrothermal alteration systems: A conceptual approach;Geochim. Cosmochim. Acta 48 2693–2711
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. 25 219–234
Lutz T M and Srogi L 1986 Biased isochron ages resulting from subsolidus isotope exchange: A theoretical model and results;Chem. Geol. 56 63–71
McCarthy T S and Cawthorn R G 1980 Changes in initial87Sr/86Sr ratio during protracted fractionation in igneous complexes;J. Petrol. 21 245–264
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. 113–116
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, 203–207
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 1133–1159
Panigrahi M K 1992Copper-Molybdenum mineralization and associated granitoids at Malanjkhand, MP, India (unpublished) Ph.D. Thesis I.I.T., Kharagpur, pp. 153
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) 275–290
Roddick J C and Compston W 1977 Strontium isotopic equilibration: A solution to a paradox;Earth Planet. Sci. Lett. 34 238–246
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), 450–470
Schaltegger U 1990 Post-magmatic resetting of Rb-Sr whole rock ages—A study in the Central Aar granites (Central Alps, Switzerland);Geologische Rundschau 79/3 709–774
Sikka D B 1989 Malanjkhand: Proterozoic porphyry copper deposit, MP, India;J. Geol. Soc. India 34 487–504
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. 207
Tripathy C 1974 The Malanjkhand-Taregaon porphyry copper deposit;Misc. Publ. GSI,34 161–168
Vistelius A B and Faas A V 1991 On the precision of age measurements by Rb-Sr Isochrons in non-trivial cases;Math. Geol. 23 999–1040
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 2349–2358
Wendt I and Carl C 1991 A statistical distribution of the mean squared weighted deviation;Chem. Geol. (Isotope Geosc. Section) 86 275–285
Williamson J H 1968 Least square fitting of a straight line;Can. J. Phys. 46 1845–1847
York D 1969 Least-square fitting of a straight line with correlated errorsEarth Planet. Sci. Lett. 5 320–324
Author information
Authors and Affiliations
Additional information
The term ‘granitoids’ is being used broadly to include rocks ranging in composition from alkali-granite to tonalite.
Rights and permissions
About this article
Cite this article
Panigrahi, M.K., Mookherjee, A., Pantulu, G. et al. Granitoids around the Malanjkhand copper deposit: Types and age relationship. Proc. Indian Acad. Sci. (Earth Planet Sci.) 102, 399–413 (1993). https://doi.org/10.1007/BF02861511
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02861511