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The geochemistry of biotites from granites of northern Portugal with special reference to their tin content

Published online by Cambridge University Press:  05 July 2018

A. M. R. Neiva*
Affiliation:
Department of Mineralogy and Geology, University of Coimbra, Portugal

Summary

Biotites from a number of granites have been analysed for major oxides and a wide range of trace elements. Their compositions are found to be typical of biotites from granite and to show element fractionation in presumed differentiation series. Estimates are made of the fugacity of oxygen and water during the crystallization of the granites. PH2O is found to increase slightly through the differentiation series, and fO2, for a temperature of 700°C is estimated to be between 10−18 and 10−12. Tin mineralization is connected with the igneous rocks and the relationship of tin in the micas to the rock compositions is described and the factors controlling the distribution of tin are discussed. The biotites have only up to 21 % of the tin of the granites. In general Sn increases in the biotites with decreasing temperature of equilibration and with increase in the degree of albitization of the granites. High Sn in biotites seems to be an indicator of potential mineralization.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1976

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Footnotes

1

Present address: University of Brasilia, 70-000 Brasilia, D.F., Brazil

References

Albuquerque, (C. A. R.), 1973. Geochimica Acta, 37, 1779-802.CrossRefGoogle Scholar
Barsukov, (V. L.) [БaρcyкoB (B. Ʌ.)], 1957. Geochemistry, 41-51 (transl. of ГeoxиMия).Google Scholar
Barsukov, (V. L.) and Durasova, (N. A.) [БaρcyкoB (B. Ʌ.) и дyρacoBa (H. A.)], 1968. Geochemistry Int. 3, 97-107 (transl. of гeoxиMия, 168-79).Google Scholar
Dmitriyev (= Dmitriev), (L. V.), Kotina, (R. P.), and Moiseyeva (= Moiseeva), (R. P.) [ДMиTρиeB (Ʌ. B.), KoTиHa (ρ. П.) и (MoйceeBa (ρ. П.)], 1962. Geochemistry, 248-65 (transl. of гeoxиMия, 220-35).Google Scholar
Engel, (A. E. J.) and Engel, (C. G.), 1960. Geol. Soc. Amer. Bull. 71, 1-58.CrossRefGoogle Scholar
Foster, (M. D.), 1960. Geol. Surv. Prof. Paper 354B, 1-49.Google Scholar
Fyfe, (W. S.), 1970. Geol. Journ. Special Issues, 15, 187-216.Google Scholar
Gokhale, (N. W.), 1968. Bull. Comm. Geol. Finlande, 40, 107-11.CrossRefGoogle Scholar
Heinrich, (E. W.), 1946. Amer. Journ. Sci. 244, 836-48.CrossRefGoogle Scholar
Hesp, (W. R.), 1971. Geochemical Exploration. Canadian Inst. Mining Metallurgy Spec, 11, 341-53.Google Scholar
Ishikawa, (H.), Shibata, (H.), and Negishi, (R.), 1963. Japanese Journ. Geol. Geogr. 34, 67-80.Google Scholar
Karayeva (= Karaeva), (Z. G.) [КaρaeBa (З. Г.)], 1968. Dokl. Akad. Nauk S.S.S.R., Earth Science Sect., 179, 164-6 (transl. of Дoкʌ. aкaд. Hayк CCCρ).Google Scholar
Kozlov, (V.) [Koзaob, (B.)], 1969. Geochemistry Int. 6, 269-80 (transl. of FeoxiiMna, 309-21).Google Scholar
Levashev, (G. B.), Strizhkova, (A. A.), and Golubeva, (E. D.) [ɅeBaШeB (Г. Б.), CTρижкOBa (A. A.), и ГoʌyбeBa (E. Д.)], 1971. Doklady. Akad. Nauk S.S.S.R., 202, 207-10 (transl. of Дoкʌ. aкaд. Hayк CCCρ).Google Scholar
Lyakhovich, (V. V.) [ДOXOBИЧ (B. B.)], 1970. Geochemistry Int. 7, 824-34 (transl. of ГeoxиMия, 1215-24).Google Scholar
Mogarovskiy, (V. V.) and Mel'nichenko, (A. K.) [MorapoBCкий (B. B.) и MeʌbHичeHкO (A. K.)], 1968. Ibid. 5, 893-99 (transl. of ГeoxиMия, 1088-96).Google Scholar
Neiva, (A. M. R.), 1971. Unpublished Ph.D. dissertation, University of Cambridge, England.Google Scholar
Nicholls, (G. D.), Graham, (A. L.), Williams, (E.), and Wood, (M.), 1967. Anal. Chem. 39, 584-90.CrossRefGoogle Scholar
Nockolds, (S. R.), 1947. Amer. Journ. Sci. 245, 401-20.CrossRefGoogle Scholar
Nockolds, (S. R.) and Mitchell, (R. L.), 1948. Trans. Roy. Soc. Edin. 61, 533-75.CrossRefGoogle Scholar
Norrish, (K.) and Hutton, (J. L.), 1969. Geochimica Acta, 33, 431-53.CrossRefGoogle Scholar
Rub, (M. G.), 1972. Chem. Geology, 10, 89-98.CrossRefGoogle Scholar
Oliveira, (J. M. S.), 1972. Estudos, Notas e Trabalhos do S. F. M., Portugal, 19, 227-75.Google Scholar
Sen, (N.), Nockolds, (S. R.), and Allen, (R.), 1959. Geochemica Acta, 16, 58-78.CrossRefGoogle Scholar
Tauson, (L. V.) [Taycoh, (Λ. B.)], 1967. Geochemistry Int. 4, 1067-75 (transl. of ГeoxиMия, 1310-9).Google Scholar
Wones, (D. R.) and Eugster, (H. P.), 1965. Amer. Min. 50, 1228-72.Google Scholar