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The quartz-plagioclase gneisses of Western Connemara, Ireland

Published online by Cambridge University Press:  01 May 2009

R. E. K. Benjamin
Affiliation:
Warren Spring Laboratory, Gunnels Wood Road, Stevenage, Herts.

Summary

Chemical analysis of twenty-six amphibolite facies gneisses from western Connemara are treated statistically, and used in conjunction with petrographic evidence to elucidate their origins. It is shown that the gneisses are of igneous ancestry, and have been invaded by material of silica-soda potash composition. The conditions of temperature and pressure prevailing at different times is related to the evolved mineral assemblages, and the whole sequence fitted into the general pattern of events in Connemara.

Type
Articles
Copyright
Copyright © Cambridge University Press 1968

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References

REFERENCES

Binns, R. A. 1964. Zones of progressive regional metamorphism in the Willyama complex, Broken Hill District, New South Wales. J. geol. Soc. Aust., 11, 283330.CrossRefGoogle Scholar
Burri, C. & Niggli, P. 1945 and 1949. Die jungen eruptivegesteine des Mediterranean orogens. Vols. 1 and 2. Vulkaninstitut Immanuel Freidlander, Zurich.Google Scholar
Burke, K. C. 1963. Age relations in the Connemara migmatites and the Galway granite—a reply. Geol. Mag., 100, 470–1.CrossRefGoogle Scholar
Joplin, G. A. 1933. Petrology of the Hartley District. II—the metamorphosed gabbros and associated hybrid and contaminated rocks. Proc. Linn. Soc. N.S.W., 58, 125158.Google Scholar
Leake, B. E. 1958. The Cashel-Lough Wheelaun intrusion, Co. Galway. Proc. R. Ir. Acad., 59 B, 155203.Google Scholar
Leake, B. E. 1964. The chemical distinction between ortho- and para-amphibolites. J. Petrol., 5, 238254.CrossRefGoogle Scholar
Leake, B. E. & Leggo, P. J. 1963. Age relations of the Connemara migmatites and the Galway granite. Geol. Mag., 100, 195203.CrossRefGoogle Scholar
Leggo, P. J. 1966. A study of the potash feldspar gneisses of Connemara, and feldspar comparison with the Galway Granite. Geol. Mag., 103, 522533.CrossRefGoogle Scholar
Leggo, P. J. Compston, W. & Leake, B. E. 1966. The geochronology of the Connemara granites, and its bearing on the antiquity of the Dalradian series. Q. Jl geol. Soc. Lond., 122, 91118.CrossRefGoogle Scholar
Orville, P. M. 1960. Alkali-feldspar/alkali-chloride hydrothermal ion exchange. Yb. Carnegie Instn. Wash., 59, 104–8.Google Scholar
Orville, P. M. 1962. Alkali metasomatism and the feldspars. Norsk geol. Tidsskr., 42, 283316.Google Scholar
Ramberg, H. 1952. The origin of metamorphic and metasomatic rocks. University of Chicago Press.Google Scholar
Read, H. H. 1923. Petrology of the Arnage district—a study in assimilation. Q. Jl geol. Soc. Lond., 79, 446486.CrossRefGoogle Scholar
Suk, M. 1964. Material characteristics of the metamorphism and migmatization of Moldanubian paragneisses in Central Bohemia. Krystallinikum, 2, 71103.Google Scholar
Wager, L. R. 1932. Geology of the Roundstone district, Co. Galway. Proc. R. Ir. Acad., 41 B, 4672.Google Scholar