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Pyroxene and biotite from the charnockitic rocks of Garbham area, Srikakulam district, Andhra Pradesh, India

Published online by Cambridge University Press:  05 July 2018

C. Bhattacharyya
C. Bhattacharyya*
Affiliation:
Department of Geology, Presidency College, Calcutta 12, India
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Summary

Chemical analyses and optical properties of ten orthopyroxenes, two clinopyroxenes, and six biotites (partial analyses) are presented from basic to intermediate charnockites of the Garbham area. The orthopyroxene is hypersthene to ferrohypersthene and the clinopyroxene is sahlite. Biotite has secondarily formed from pyroxene, particularly orthopyroxene, as a result of injection of potassic fluid in the basic charnockite. By combining the data of Srikakulam with those from other areas of the world it is shown that during the transformation of pyroxene to biotite in charnockitic rocks, in general, Mg and Fe 2+ attain near-equilibrium distribution between orthopyroxene and biotite as well as between clinopyroxene and biotite. The magnesium distribution coefficient (KD) of coexisting orthopyroxene and biotite is found to increase with the increase of temperature of biotite formation. A tentative geothermometric scale has been proposed plotting temperature of biotite formation against magnesium distribution coefficient of coexisting orthopyroxene and biotite. According to this scale, biotite in basic and semibasic charnockites from Garbham has formed between 285 and 465 °C.

Type
Research Article
Information
Mineralogical Magazine , Volume 37 , Issue 290 , June 1970 , pp. 682 - 692
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1970

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References

Atherton, (M. P.), 1965. In Pitcher, (W. S.) and Flinn, (G. W.) (eds.), Controls of Metamorphism, p. 169. Geol. Journ. Spec. Issue (Oliver & Boyd).Google Scholar
Bhattacharyya, (C.), 1969. Bull. Geol. Soc. India, 6, 123.Google Scholar
Buddington, (A. F.), 1965. Min. Mag. 34, 71.Google Scholar
Buddington, (A. F.), and Lindsley, (D. H.), 1964 . Journ. Petrology, 5, 310.CrossRefGoogle Scholar
Deer, (W. A.), Howie, (R. A.), and Zussman, (J.), 1963. Rock-forming Minerals, 2. London (Longmans).Google Scholar
Engel, (A. E. J.), Engel, (C. G.), and Havens, (R. G.), 1964. Journ. Geol. 72, 131.CrossRefGoogle Scholar
Groves, (A. W.), 1935. Quart. Journ. Geol. Soc. London, 91, 150.10.1144/GSL.JGS.1935.091.01-04.06CrossRefGoogle Scholar
Hall, (A. J.), 1941 Amer. Min. 26, 34.Google Scholar
Hallimond, (A. F.), 1947. Min. Mag. 28, 230.Google Scholar
Heinrich, (E. WM.), 1964. Amer. Journ. Sci. 244, 836.CrossRefGoogle Scholar
Hess, (H. H.), 1960. Geol. Soc. Amer. Mem. 80.Google Scholar
Hess, (H. H.), and Phillips, (A. H.), 1940. Amer. Min. 25, 271.Google Scholar
Howie, (R. A.), 1955. Trans. Roy. Soc. Edinb. 62, 725.CrossRefGoogle Scholar
Howie, (R. A.), 1964a. Min. Mag. 33, 903.Google Scholar
Howie, (R. A.), 1964b. Sci. Progress, 52, 628.Google Scholar
Howie, (R. A.), 1965a. Indian Mineralogist, 6, 67.Google Scholar
Howie, (R. A.), 1965b. In Pitcher, (W. S.) and Flinn, (G. W.) (eds.), Controls of Metamorphism, p. 319 Geol. Journ. Spec. Issue (Oliver & Boyd).Google Scholar
Howie, (R. A.) and Subramaniam, (A. P.), 1957. Min. Mag. 31, 565.Google Scholar
Kretz, (R.), 1963. Journ. Geol. 71, 773.10.1086/626953CrossRefGoogle Scholar
Kuno, (H.), 1954. Amer. Min. 39, 30.Google Scholar
Lakshmi Naravana Rao, (S. V.), 1967. Journ. Geol. Soc. India, 8, 93.Google Scholar
Larsen, (E. S.) Jr. and Draisin, (W. M.), 1950. Int. Geol. Cong., 18th Session, pt. 2, p. 66.Google Scholar
Leelanandam, (C.), 1967. Min. Mag. 36, 153.Google Scholar
Murty, (M. S.), 1965. Ibid. 35, 393.CrossRefGoogle Scholar
Naidu, (P. R. J.), 1955. Schweiz. Min. Petr. Mitt. 34, 203.Google Scholar
Nockolds, (S. R.), 1947. Amer. Journ. Sci. 245, 401.CrossRefGoogle Scholar
Poldervaart, (A.) and Hess, (H. H.), 1951. Journ. Geol. 59, 472.CrossRefGoogle Scholar
Subramaniam, (A. P.), 1962. Geol. Soc. Amer., Buddington volume, 21.Google Scholar