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A Study of Possible Factors concerning Garnet Formation in Rocks from Ardara, Co. Donegal, Ireland

Published online by Cambridge University Press:  01 May 2009

K. A. Jones  and
A. K. Galwey
K. A. Jones
Affiliation:
Dept. of Geology (K. A. J.) and Dept. of Chemistry (A. K. G.), The Queen's University, Belfast.
A. K. Galwey
Affiliation:
Dept. of Geology (K. A. J.) and Dept. of Chemistry (A. K. G.), The Queen's University, Belfast.
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Abstract

Chemical and modal analyses have been made for a series of ten homogeneous specimens of meta-sediments, with identical metamorphic histories, from the aureôle of the Ardara pluton. Results showed that total amount of garnet was determined by the quanity of “free ferrous oxide” (assuming that the reaction: FeO + Fe2O3→ Fe3O4, has gone to completion) in the rock. Size distribution curves showed that each specimen contained crystals with a preferred radius and throughout the series a quantitative relation between the preferred radius and the frequency distribution about this value was observed.

Measurement of the number of crystals per unit volume showed that this gave trends with functions of the chemical composition of the rock. A discussion of the mechanism of garnet formation in terms of chemical laws of nucleation and growth is given.

Type
Articles
Information
Geological Magazine , Volume 101 , Issue 1 , 06 February 1964 , pp. 76 - 93
Copyright
Copyright © Cambridge University Press 1964

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References

REFERENCES

Akaad, M. K., 1956. The Northern aureôle of the Ardara pluton of County Donegal. Geol. Mag., 93, 377–392.CrossRefGoogle Scholar
Chinner, G. A., 1960. Pelitic Gneisses with varying ferrous/ferric ratios from Glen Clova, Scotland. J. Petrology, 1, 178–217.CrossRefGoogle Scholar
Fyfe, W. S., Turner, F. J., and Verhoogen, J., 1958. Metamorphic reactions and metamorphic facies. Mem. geol. Soc. Amer., 73.Google Scholar
Groves, A. W., 1951. Silicate Analysis, 2nd Ed., London: George Allen and Unwin.Google Scholar
Hillebrand, W. F., and Lundell, G. E. F., 1950. Applied Inorganic analysis: with special reference to the analysis of metals, minerals, and rocks. New York: Wiley.Google Scholar
Holmes, A. H., 1927. Petrographic Methods and Calculations, London: Murby and Co.Google Scholar
Hull, F. C., and Houk, W. J., 1953. Statistical grain structure studies: Plane distribution curves of regular polyhedrons. J. Metals, 195, 565–572.Google Scholar
Jacobs, P. W. M., and Tompkins, F. C., 1955. Chapter 7. Chemistry of the solid state. Ed. Garner, W. E. London: Butterworths.Google Scholar
Korzhinskii, D. S., 1959. Physicochemical basis of the analysis of the paragenesis of minerals. Translation by Consultants bureau, New York.Google Scholar
Niggli, P., 1954. Rocks and mineral deposits. Translation by Parker, R. L.. San Francisco: Freeman and Co.Google Scholar
Pitcher, W. S., and Sinha, R. C., 1958. The petrochemistry of the Ardara Aureôle. Quart. J. geol. Soc. London, 113, 393–408.CrossRefGoogle Scholar
Ramberg, H., 1952. The origin of metamorphic and metasomatic rocks. Chicago: The University Press.Google Scholar