Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-27T07:01:03.472Z Has data issue: false hasContentIssue false
  • English
  • Français

Epitaxic relations between coexisting pyroxenes

Published online by Cambridge University Press:  05 July 2018

J. Tarney
J. Tarney*
Affiliation:
Department of Geology, The University, Birmingham 15
Get access Rights & Permissions [Opens in a new window]

Summary

Many examples of epitaxic relations between coexisting pyroxenes are found in the picritic dykes that cut the Lewisian gneisses of the Lochinver area, Sutherland. In some dykes augite forms oriented overgrowths on the (100) face of orthopyroxene; in others orthopyroxene forms similar overgrowths on augite. A number of unusual variants of the first case are described together with a complex ‘induced’ twinning found in the augite overgrowths. Analyses of the coexisting pyroxenes suggest that the overgrowth relation has been facilitated by increased solid solution between the pyroxenes, so reducing the crystallographic misfit along the c-axis. However, crystallization of the pyroxenes in an ordered sequence rather than simultaneously also seems to have been an important factor.

Type
Research Article
Information
Mineralogical Magazine , Volume 37 , Issue 285 , March 1969 , pp. 115 - 122
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1969

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bowes, (D. R.), Wright, (A. E.), and Park, (R. G.), 1964. Quart. Journ. Geol. Soc. 120, 153-92.CrossRefGoogle Scholar
Brown, (G. M.), 1957. Mitt. Mag. 31, 511-47.Google Scholar
Buckley, (H. E.), 1951. Crystal Growth. New York (Wiley).Google Scholar
Dearnley, (R.), 1963. Quart. Journ. Geol. Soc. 119, 243-307.CrossRefGoogle Scholar
Evans, (C. R.) and Tarney, (J.), 1964. Nature, 204, 638-41.CrossRefGoogle Scholar
Green, (D. H.) and Ringwood, (A. E.), 1964. Ibid. 201, 1276-9.10.1038/2011276a0CrossRefGoogle Scholar
Hess, (H. H.), 1952. Amer. Journ. Sci., Bowen Volume, 173-87.Google Scholar
Kuno, (H.), 1954. Amer. Min. 19, 30-45.Google Scholar
Merwe, (J. H. Van Der), 1949. Discussions of the Faraday Society, No. 5, 201 14.10.1039/df9490500201CrossRefGoogle Scholar
O'Hara, (M. J.), 1961. Min. Mag. 32, 848-65.Google Scholar
O'Hara, (M. J.), 1962. Trans. Edinb. geol. Soc. 19, 201-7.CrossRefGoogle Scholar
Peach, (B. N.) and others, 1907. The Geological Structure of the North-West Highlands of Scotland. Mem. Geol. Survey, G.B.Google Scholar
Poldervaart, (A.) and Taubeneck, (W. H.), 1960. Rept. 21st Internat. Geol. Congr., Norden, 13, 239-46.Google Scholar
Tarney, (J.), 1963. Nature, 199, 672-4.CrossRefGoogle Scholar
Yoder, (H. S.) and Tilley, (C. E.), 1962. Journ. Petrology, 3, 342 532.CrossRefGoogle Scholar