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U, Th, and K distribution in a differentiated charnockite-granite intrusion and associated rocks from SW Sweden

Published online by Cambridge University Press:  05 July 2018

J. L. Constable  and
F. H. Hubbard
J. L. Constable
Affiliation:
Department of Geology, The University, Dundee, DD1 4HN, Scotland
F. H. Hubbard
Affiliation:
Department of Geology, The University, Dundee, DD1 4HN, Scotland
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Abstract

The concentrations of U, Th, and K in a charnockite-alkali granite intrusive complex from SW Sweden and associated, partly charnockitized country rocks are presented. The charnockitic components have constant low U and Th levels throughout the compositional range with a mean Th/U ratio of 1.2 to 1.5. The transition from charnockite to granite is marked by a sharp increase in Th and U concentrations with mean Th/U ratios increasing to 3.4 4.4. However, the K concentration increases relatively smoothly with increasing acidity through the compositional range studied. Late shearing of the alkali granite led to significant Th depletion with little change in the U and K concentrations. Charnockitization of the country rock granite gneisses is marked by depletion in Th and K while the U content is almost unchanged.

It is suggested that the behaviour of U and Th reflects the tendency for Th to associate with magma-dissolved water whilst U shows a greater affinity for coexisting free volatiles. In the absence of a significant free volatile phase during crystallization of this charnockite-granite suite, U was incorporated into primary mineral lattice sites whereas Th entered sites from which it could be liberated more easily.

Type
Research Article
Information
Mineralogical Magazine , Volume 44 , Issue 336 , December 1981 , pp. 409 - 415
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1981

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Footnotes

*

Present address: Department of Geology, University of Keele, Keele, Staffordshire.

References

Adams, J. A. S. and Gasparini, P. (1970). Gamma-ray Spectrometry of Rocks, Elsevier, Amsterdam.Google Scholar
Clark, S. P., Peterman, Z. E., and Heier, K. S. (1966). Geol. Soc. Am. Mem. 97.Google Scholar
Heier, K. S. and Rogers, J. J. W. (1963). Geochim. Cosmochim. Acta, 27, 137-54.CrossRefGoogle Scholar
Heier, K. S. and Thoresen, K. (1971). Ibid. 35, 35-99.Google Scholar
Holloway, J. R. (1976). Geol. Soc. Am. Bull. 87, 87-18.2.0.CO;2>CrossRefGoogle Scholar
Hubbard, F. H. (1975). Geol. F6ren. Stockholm F6rh. 97, 97-36.Google Scholar
Hubbard, F. H. (1978). Ibid. 100, 31-8.Google Scholar
Hubbard, F. H. and Constable, J. L. (1980). Ibid. 102, 40-2.Google Scholar
Hubbard, F. H. and Whitley, J. E. (1978). Nature, 271, 439-40.CrossRefGoogle Scholar
Hubbard, F. H. (1979). Lithos, 12, 1–11.CrossRefGoogle Scholar
Killeen, P. G. and Heier, K. S. (1975a). Chem. Geol. 15, 163-76.CrossRefGoogle Scholar
Killeen, P. G. and Heier, K. S. (1975b). Nor. Geol. Unders. 319, 59-83.Google Scholar
Killeen, P. G. and Heier, K. S. (1975c). Geochim. Cosmochim. Acta, 39, 1515-24.CrossRefGoogle Scholar
Killeen, P. G. and Heier, K. S. (1975d). Det. Norske Videnskaps-Akademie 1. Mat-Naturv. Klasse No. 35, 35-32.Google Scholar
Larsen, E. S. 3rd. and Gottfried, D. (1960). Am. J. Sci. 258-A, 151-69.Google Scholar
Nockolds, S. R. (1954). Geol. Soc. Am. Bull. 65, 65-32.CrossRefGoogle Scholar
Raade, G. (1973). Unpubl. Cand. Real. thesis, Univ. of Oslo.Google Scholar
Rogers, J. J. W. and Adams, J. A. S. (1969). In Handbook of Geochemistry. Wederpohl, K. H. (ed.) Springer-Verlag, Berlin.Google Scholar
Rogers, J. J. W. and Ragland, P. C. (1961). Geochim. Cosmochim. Acta, 25, 25-109.CrossRefGoogle Scholar
Sheraton, J. W., Skinner, A. C., and Tarney, J. (1973). In The Early Precambrian of Scotland and related rocks of Greenland. Park, R. G. and Tarney, J. (eds.) University of Keele.Google Scholar
Smithson, S. B. and Decker, E. R. (1973). Earth Planet. Sci. Letters, 19, 19-4.CrossRefGoogle Scholar
Smithson, S. B. and Heier, K. S. (1971). Ibid. 12, 325-6.Google Scholar
Welin, E. and Gorbatschev, R. (1978). Geol. Fören. Stockholm Fören. 100, 100-7.Google Scholar