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Some orthopyroxenes from Scottish metamorphic rocks

Published online by Cambridge University Press:  14 March 2018

R. A. Howie*
Affiliation:
Department of Geology, King's College, London

Summary

Chemical analyses, cell parameters, and optical properties are presented for seven Scottish orthopyroxenes: four from Harris, two from Scourie, and one from Belhelvie, Aberdeenshire. The compositions range from En83·6 to En55·5. Six of the orthopyroxenes are from pyroxene granulites or related rocks and the other is from a plagioclase-hypersthene hornfels: the latter mineral is notable in having 7·21% Al2O3, causing a considerable contraction in the a and b cell parameters. The alumina content of orthopyroxenes is briefly discussed. Analyses are also given for olivine and diopsidic augite from a South Harris ultrabasic gneiss and for two enderbitic pyroxene gneisses from Scourie.

Type
Research Article
Copyright
Copyright © 1964, The Mineralogical Society

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References

Boyn, (F.R.) and Engl).ND, (J.L.), 1960. Minerals of the mantle: aluminous enstatite. Carnegie Instn. of Washington Year Book 59, p. 49.Google Scholar
Dhvidson, (C.R.), 1943.The Archaean rocks of the Rodil district, South Harris, Outer Hebrides. Trans. Roy. Soc. Edinburg., vol. 61, p. 71.[M.A. 9-166].Google Scholar
Hess, (H.H.), 1952. Orthopyroxenes of the Bushveld type, ion substitutions and changes in unit cell dimensions. Amer. Journ. Sci., Bowen vol., p. 173.[M.A. 12-92].Google Scholar
Holland, (T.H.), 1900. The charnockite series, a group of Archaean hypersthene rocks in peninsular India. Geol. Surv. India, Mere. 74, p. 31.Google Scholar
Howie, (R.A.), 1955.The geochemistry of the charnockite series of Madras, India. Trans. Roy. Soc. Edinburg., vol. 62, p. 725.[M.A. 13-351].Google Scholar
Howie, (R.A.), 1963. Cell parameters of orthopyroxenes. Min. Soc. Amer., Special Paper 1 (Intern. Min. Assoc., Papers, 3rd Gem Meeting), p. 213.Google Scholar
Jehu, (T.J.) and Caaig, (R.M.), 1927.Geology of the Outer Hebrides. Part IV. South Harris. Trans. Roy. Soc. Edinburg., vol. 55, p. 457.CrossRefGoogle Scholar
Jehu, (T.J.) 1934. Geology of the Outer Hebrides. Part V. North Harris and Lewis, Ibid., vol. 107, p. 839.Google Scholar
O'Hara, (M.J.), 1961.Zoned ultrabasic and basic gneiss masses in the early Lewisian metamorphic complex at Scourie, Sutherland. Journ. Petrolog., vol. 2, p. 248.Google Scholar
Peach, (B.N.) et al., 1907. The geological structure of the North-West Highlands of Scotland. Mere. Geol. Surv. Scotland.Google Scholar
Stewart, (F.H.), 1946.The gabbroic complex of Belhelvie in Aberdeenshire. Quart. Journ. Geol. Soc. Londo., vol. 102,p. 465.[M.A. 10-281].Google Scholar
Sutton, (J.) and Watson, (J.), 1950.The pre-Torridonian metamorphic history of the Loch Torridon and Scourie areas in the North-West Highlands, and its bearing on the chronological classification of the Lewisian. Ibid., vol. 106, p. 24.Google Scholar