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XVIII.—A Re-examination of Barrow's Older Granites in Glen Clova, Angus*

Published online by Cambridge University Press:  06 July 2012

William Trevelyan Harry
William Trevelyan Harry
Affiliation:
Department of Geology, University of St Andrews.
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Synopsis

Barrow describes from Glen Clova an important Older Granite intrusion, the muscovite-biotite-gneiss which he holds responsible for the formation of staurolite, kyanite and sillimanite zones of progressive regional metamorphism in the district. He states that the gneiss was filter-pressed during emplacement so that potash was strained off and concentrated in the south-eastern outcrops of the intrusion leaving its north-western portions enriched in soda. He claims that by the same process the separate intrusive areas comprising the gneiss have often been marginally enriched in potash and pegmatite.

The factual basis of the filter-press hypothesis does not withstand careful re-examination. The individual intrusive areas of muscovite-biotite-gneiss bear no marginal zones of potash and pegmatite enrichment like those envisaged by Barrow. The muscovite-biotite-gneiss in its entirety comprises two distinct units, a heterogeneous group of banded quartz-oligoclase-mica-gneisses that were intensely deformed plastically during high-grade metamorphism, and a later series of non-migmatitic microcline-granite intrusions. In neither unit can any regular variation in potash/soda ratio be detected in passing directly from north-west to south-east.

New data are provided concerning the distribution and mode of occurrence of Barrow's metamorphic zonal index minerals. Sillimanite, as fibrolite, often replaces mica and accompanies kyanite in specimens from many localities.

Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 63 , Issue 2 , 1958 , pp. 393 - 412
Copyright
Copyright © Royal Society of Edinburgh 1958

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References

References to Literature

Anderson, J. G. C., 1942. “The Stratigraphical Order of the Dalradian Schists near the Highland Border in Angus and Kincardine”, Trans. Geol. Soc. Glasg., 20, 223–237.CrossRefGoogle Scholar
Barrow, G., 1892. “On certain Gneisses with Round-grained Oligoclase and their Relations to Pegmatites”, Geol. Mag., 9, 64–65.CrossRefGoogle Scholar
Barrow, G., 1893. “On an Intrusion of Muscovite-biotite-Gneiss in the South-eastern Highlands of Scotland, and its accompanying Metamorphism”, Quart. J. Geol. Soc., 49, 330–358.CrossRefGoogle Scholar
Barrow, G., 1912 a. “The Geology of the Districts of Braemar, Ballater and Glen Clova”, Mem. Geol. Surv. U.K.Google Scholar
Barrow, G., 1912 b. “On the Geology of Lower Deeside and the Southern Highland Border”, Proc. Geol. Ass. Lond., 23, 274–290.CrossRefGoogle Scholar
Fairbairn, H. W., 1941. “Deformation Lamellæ in Quartz from the Ajibik Formation, Michigan”, Bull. Geol. Soc. Amer., 52, 1265–1278.CrossRefGoogle Scholar
Harry, W. T., 1954. “The Composite Granitic Gneiss of Western Ardgour, Argyll”, Quart. J. Geol. Soc., 109, 285–309.CrossRefGoogle Scholar
Hietanen, A., 1956. “Kyanite, Andalusite and Sillimanite in the Schist in Boehls Butte Quadrangle, Idaho”, Amer. Min., 41, 1–27.Google Scholar
Hill, J. B., 1905. “The Geology of Mid-Argyll”, Mem. Geol. Surv. U.K., 18.Google Scholar
MacGregor, A. G., 1928. “Metamorphism around the Lochnagar Granite, Aberdeenshire”, Rept. Brit. Ass., 1928, 553–554.Google Scholar
McIntyre, D. B., 1951. “Note on the Tectonic Style of the Ord Ban Quartzites, Mid-Strathspey”, Geol. Mag., 88, 50–54.CrossRefGoogle Scholar
Phillips, F. C., 1930. “Some Mineralogical and Chemical Changes induced by Progressive Metamorphism in the Green Bed Group of the Scottish Dalradian”, Min. Mag., 22, 239–256.Google Scholar
Read, H. H., 1931. “The Geology of Central Sutherland”, Mem. Geol. Surv. U.K.Google Scholar
Robertson, D. S., 1953. “Batty Lake Map-area, Manitoba”, Mem. Geol. Surv. Can., 271.Google Scholar
Sander, B., 1950. Einführung in die Gefügekunde der geologischen Körper, 2. Wien und Innsbrück.CrossRefGoogle Scholar
Tozer, C. F., 1955. “The Mode of Occurrence of Sillimanite in the Glen District, Co. Donegal”, Geol. Mag., 92, 310–320.CrossRefGoogle Scholar
Watson, J., 1948. “Late Sillimanite in the Migmatites of Kildonan, Sutherland”, Geol. Mag., 85, 149–162.CrossRefGoogle Scholar
Wiseman, J. D. H., 1934. “The Central and South-west Highland Epidiorites: A Study in Progressive Metamorphism”, Quart. J. Geol. Soc., 90, 354–417.CrossRefGoogle Scholar