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Mineral chemistry of coexisting phases from shonkinitic rocks, Salem, Tamil Nadu, India

Published online by Cambridge University Press:  05 July 2018

C. R. L. Friend  and
A. S. Janardhan
C. R. L. Friend
Affiliation:
Department of Geology and Physical Sciences, Oxford Polytechnic, Oxford OX3 0BP, UK
A. S. Janardhan
Affiliation:
Department of Geology, University of Mysore, Manasagangotri, Mysore 570006, India
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Abstract

Gabbroic-textured shonkinitic rocks of unknown age cut deformed Archaean dunites and peridotites in the area immediately north of Salem. Magnesite formation post-dates their intrusion. The location of these rocks and the magnesite is thought to be controlled by the intersection of two major basement lineaments. A sequence of crystallization of the minerals and rocks from early undersaturated to late oversaturated rocks is established. Compositions of the coexisting mineral phases are reported here for the first time. Clinopyroxenes, which are relatively unevolved, commonly coexist with olivine (chrysolite) and sanidine. Bronzite, often intergrown with magnetite and green spinel, is occasionally present. In the most undersaturated rocks nepheline-sanidine fingerprint intergrowths occur, whilst perthitic sanidine, albitic plagioclase, and quartz are present in over-saturated rocks. Late in the crystallization sequence, in over-saturated rocks, PH2O appears to have increased allowing the formation of amphibole as well as clinopyroxene.

Type
Research Article
Information
Mineralogical Magazine , Volume 48 , Issue 347 , June 1984 , pp. 181 - 193
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1984

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References

Ambler, E. P., and Ashley, P. M. (1977) Lithos. 10, 163–72.CrossRefGoogle Scholar
Davidson, A. (1970) Can. Mineral. 10, 191–206.Google Scholar
Deer, W. A., Howie, R. A, and Zussman, J. (1963) Rock-forming Minerals, 4, Longmans, London, 435 pp.Google Scholar
Deer, W. A., Howie, R. A, and Zussman, J. (1978) Ibid. 2a, 668 pp.Google Scholar
Drury, S. A., and Holt, R. W. (1980) Tectonophys. 65, T1–T15.CrossRefGoogle Scholar
Fudali, R. F. (1963) Bull. geol. Soc. Am. 74, 1101–25.CrossRefGoogle Scholar
Gibb, F. G. F. (1973) J. Petrol. 14, 203–30.CrossRefGoogle Scholar
Goode, A. D. T. (1974) Nature. 248, 500–1.CrossRefGoogle Scholar
Hamilton, D. L., and Mackenzie, W. S. (1965) Mineral. Mag. 34, 214–31.Google Scholar
Hurlbut, C. S., and Griggs, D. (1939) Bull. geol. Soc. Am. 50, 1043–112.CrossRefGoogle Scholar
Irving, A. J. (1974) Ibid, 85, 1503–14.Google Scholar
Larsen, L. M. (1976) J. Petrol. 17, 258–90.CrossRefGoogle Scholar
Le Bas, M. J. (1962) Am. J. Sci. 260, 267–88.CrossRefGoogle Scholar
Leake, B. E. (1978) Mineral. Mag. 42, 533–63.CrossRefGoogle Scholar
Mitchell, R. H. (1980) Am. Mineral. 65, 45–54.Google Scholar
Mitchell, R. H. and Platt, R. G. (1979) Contrib. Mineral. Petrol. 69, 255–64.CrossRefGoogle Scholar
Murthy, S. R. N. (1979) Rec. Geol. Suv. India. 112 (5), 15–35.Google Scholar
Naidu, P. J. R. (1963) Min. Soc. Am. Sp. Paper. 1, 251–7.Google Scholar
Nash, W. P., and Wilkinson, J. F. G. (1970) Contrib. Mineral. Petrol. 25, 241–69.CrossRefGoogle Scholar
Parsone, I. (1979) J. Petrol. 20, 653–94.CrossRefGoogle Scholar
Powell, M., and Powell, R. (1974) Contrib. Mineral. Petrol. 48, 249–63.CrossRefGoogle Scholar
Ramanathan, S. (1954) J. Madras Univ. 24, 315–33.Google Scholar
Schairer, J. F., and Yoder, H. S. (1960) Am. J. Sci. 258–A, 273–83.Google Scholar
Smith, A. L., and Carmichael, I. S. E. (1969) Am. Mineral. 54, 909–23.Google Scholar
Smith, D., and Lindsley, D. H. (1971) Carnegie Inst. Washington Yearb. 69, 269–74.Google Scholar
Sørensen, H. (1974) The Alkaline Rocks, Wiley, London, 622 pp.Google Scholar
Stephenson, D. (1972) Lithos. 5, 187–201.CrossRefGoogle Scholar
Streckeisen, A. L. (1976) Earth Sci. Rev. 12, 1–33.CrossRefGoogle Scholar
Tilley, C. E. (1954) Am. J. Sci. 252, 65–75.CrossRefGoogle Scholar
Tuttle, O. F., and Smith, J. V. (1958) Ibid, 256, 571–89.Google Scholar
Wells, P. R. A. (1977) Contrib. Mineral. Petrol. 42, 129–39.CrossRefGoogle Scholar
Wood, B. J., and Banno, S. (1973) Ibid, 42, 109–24.Google Scholar