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Inclusion patterns in zoned garnets from Magerøy, north Norway

Published online by Cambridge University Press:  05 July 2018

T. B. Andersen
T. B. Andersen*
Affiliation:
Geologisk Institutt Avd. A., 5014 University of Bergen, Norway
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Abstract

Garnet porphyroblasts in metasediments from Magerøy crystallized during static metamorphism. They display three optical zones, each having characteristic inclusions and chemistry. The compositional zoning is related to prograde metamorphism (an inner zone, 1, and a graphite-bearing zone) and retrogression (the outer zone, 2). Inclusions of two types are present in zone 1: type 1 are equidimensional remnants of the matrix, preferentially included along planes of rapid growth; type 2 are tubular and represent recrystallized quartz grains concentrated along defects in the garnet lattice. The defects are lineage boundaries between growth segments related to screw dislocations on crystal faces. Crystal growth developed at relatively high degrees of supersaturation, but below the supersaturation required for the development of dendrites. The inclusions suggest rapid growth of zone 1, caused by heat flow from an adjacent interkinematic mafic/ultramafic intrusive complex. The graphite-bearing zone crystallized at the metamorphic peak, while the inclusion-free idioblasfic rim probably developed during retrograde metamorphism.

Type
Research Article
Information
Mineralogical Magazine , Volume 48 , Issue 346 , March 1984 , pp. 21 - 26
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1984

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References

Andersen, T. B. (1979) The geology of southwest Magerey; with special reference to the tectono-metamorphic development. Cand. Real, thesis. Univ. of Bergen.Google Scholar
Andersen, T. B. (1981) Nor. geol. Unders. 363, 1–23.Google Scholar
Andersen, T. B., Austrheim, H., Sturt, B. A., Pedersen, S., and Kjasrsrud, K. (1982) Nor. geol. Tidsskr. 62, 2. 79-85.Google Scholar
Anderson, D. E., and Buckley, G. R. (1973) Contrib. Mineral. Petrol. 40, 87–104.CrossRefGoogle Scholar
Atherton, M. P., and Brenchley, P. J. (1972) Geol. J. 8, 161–78.CrossRefGoogle Scholar
Chalmers, B. (1964) Principles of Solidification. John Wiley, New York.Google Scholar
Finlay, C. A., and Kerr, A. (1979) Contrib. Mineral. Petrol. 71, 185–91.CrossRefGoogle Scholar
Goldschmidt, V. M. (1911) Die kontaktmetamorphose im Kristianiagebiet. Vidensk. Selsk. Skr. Kristiania 1.Google Scholar
Grant, J. A., and Weiblen, P. W. (1971) Am. J. Sci. 270, 281–96.CrossRefGoogle Scholar
Harker, A. (1939) Metamorphism. Methuen. London.Google Scholar
Harte, B, and Henley, K. J. (1966) Nature. 210, 689–92.CrossRefGoogle Scholar
Hollister, L. S. (1966) Science. 154, 1647–51.CrossRefGoogle Scholar
Hollister, L. S. (1970) Am. Mineral. 55, 742–66.Google Scholar
Hollister, L. S. (1977) Can. Mineral. 15, 217–29.Google Scholar
Hollister, L. S. and Bence, A. E. (1967) Science. 158, 1053–6.CrossRefGoogle Scholar
Lefever, R. A., and Chase, A. B. (1962) J. Am. Ceram. Soc. 45, 32–6.CrossRefGoogle Scholar
Lessing, P., and Standish, R. P. (1973) Am. Mineral. 58, 840–2.Google Scholar
MacQueen, J. A., and Powell, D. (1977) Geol. Soc. Am. Bull. 88, 235–40.2.0.CO;2>CrossRefGoogle Scholar
Murad, E. (1976) Mineral. Mag. 40, 715–19.CrossRefGoogle Scholar
Olimpio, J. C., and Anderson, D. E. (1978) Am. Mineral. 63, 677–89.Google Scholar
Powell, D. (1966) Mineral. Mag. 35, 1094–109.Google Scholar
Powell, D. and Treagus, J. E. (1970) Ibid. 801, 14.Google Scholar
Ramsay, D. M., and Sturt, B. A. (1976) Nor. geol. Tidsskr. 56, 291–307.Google Scholar
Schoneveld, C. (1977) Tectonophysics 39, 453–71.CrossRefGoogle Scholar
Sivaprakash, C. (1981) Mineral. Mag. 44, 301–7.CrossRefGoogle Scholar
Smith, F. G. (1963) Physical Geochemistry. Addison-Wesley, Massachusetts.Google Scholar
Spry, A. (1969) Metamorphic Textures. Pergamon Press, Oxford.Google Scholar
Tracy, R. J., Robinson, P., and Thompson, A. B. (1976) Am. Mineral. 61, 762–75.Google Scholar
Verma, A. R., and Krishna, P. (1966) Polymorphism and Polytypism in Crystals. John Wiley, New York.Google Scholar
Yardley, B. W. D. (1977) Am. Mineral. 62, 793–800.Google Scholar