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Metasomatized (fenitized) quartzites from the Borralan Complex, Scotland

Published online by Cambridge University Press:  05 July 2018

A. R. Woolley
Affiliation:
Department of Mineralogy, British Museum (Natural History), Cromwell Road, London S.W. 7
R. F. Symes
Affiliation:
Department of Mineralogy, British Museum (Natural History), Cromwell Road, London S.W. 7
C. J. Elliott
Affiliation:
Department of Mineralogy, British Museum (Natural History), Cromwell Road, London S.W. 7

Summary

Fenitized quartzites are described from three localities around the Borralan alkaline igneous complex. Chemical and electron-probe analyses of amphiboles, pyroxenes, micas, and feldspars are given. Early-formed amphiboles are calcic, but these are replaced by alkaline varieties with increasing fenitization. Rock analyses indicate a ‘straight line’ rate of increase of Ti, Fe2+ + Fe3+, Mg, Al, K, and a more variable increase of Ca and Na atoms, at the expense of Si atoms. The simple composition of the unaltered quartzite allows the accurate calculation of bulk changes during fenitization. The final product of the alkali metasomatism is a syenite lying close to the albite-orthoclase minimum though the primary source of the fenitizing fluids was probably a highly potassic magma.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1972

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References

Baker, (B.H.), 1953. Kenya Geological Survey, Report 24, 32-48.Google Scholar
Barth, (Z. F. W.), 1951. Neues Jahrb. Min. Abt. A, 82, 143-54 [M.A. 11-328].Google Scholar
Bowen, (N.L.) and Tuttle, (O.F.), 1950. Journ. Geol., 58, 489-511. [M.A. 11-325].CrossRefGoogle Scholar
Bowie, (S. H. U.), Dawson, (J.), Gallagher, (M.J.), and Ostle, (D.), 1966. Transactions of the Institution of Mining and Metallurgy, B, 75, 125-45 [M.A. 17-667].Google Scholar
Deer, (W.A.), HOWlE, (R.A.), and Zussman, (J.), 1962. Rock-forming minerals, 3, Sheet Silicates. London (Longmans and Green).Google Scholar
Leake, (B.E.), 1968. Geological Society of America, Special Paper, 98. [M.A. 20-3243].Google Scholar
Mckie, (D.), 1966. In Carbonatites, Tuttle, (O.F.), and Gittins, (J.), Editors. New York, London, Sydney (John Wiley). [M.A. 18-210].Google Scholar
Miyashiro, (A.), 1957. Journal of the Faculty of Science, University of Tokyo, 11, 58-83 [M.A. 14-- 144].Google Scholar
Poldervaart, (A.) and Hess, (H.H.), 1951. Journ. Geol. 59, 472-89 [M.A. 11-490].CrossRefGoogle Scholar
Sabine, (P.A.), GuPPy (E. M.), and Sergeant, (G.A.), 1969. Institute of Geological Sciences, Report 69/I [M.A. 20-1310].Google Scholar
Sweatman, (Z.R.) and LONG (J. V. P.), 1969. Journ. Petrology, 10, 332-76 [M.A. 20-2801].CrossRefGoogle Scholar
Tyler, (R.C.) and King, (B.C.), 1967. Min. Mag. 36, 5-21 [M.A. 18-116].Google Scholar
Woolley, (A.R.), 1969. Bulletin of the British Museum (Natural History), Mineralogy, 2, 189-219 [M.A. 21-868].Google Scholar
Woolley, (A.R.), 1970. Geological Journal, 7, 171-82 [M.A. 22-573].CrossRefGoogle Scholar