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A Columnar Growth of Dendritic Pyroxene

Published online by Cambridge University Press:  01 May 2009

J. Preston
Affiliation:
Dept. of Geology, The Queen's University, Belfast.

Abstract

One of the internal contacts of a doleritic intrusion, Co. Donegal, is lined with large augite dendrites. The habit is revealed by parting on a median zone of chlorite which is regarded as an altered exsolution feature. It is suggested that an initial platy dendrite grew, in response to undercooling, as a metastable phase with the composition and structure of a high-calcic pigeonite. A later overgrowth of augite preserved the delicate crystal against destruction.

Type
Articles
Copyright
Copyright © Cambridge University Press 1966

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References

REFERENCES

SirBragg, L., and Claringbull, G. F., 1965. The crystalline state, Vol. 4, Crystal structures of minerals. 409 pp. London.Google Scholar
Cabrera, N., and Coleman, R. V., 1963. Theory of crystal growth from the vapour. The art and science of growing crystals. Ed. Gilman, J. J., 493 pp. New York.Google Scholar
Doelter, C., 1905. Physikalisch-Chemische Mineralogie, 272 pp. Leipzig.Google Scholar
Egan, F. W., Kilroe, J. R., and Mitchell, W. F., 1888. Explanatory memoir to accompany sheet 24 of the maps. Geol. Surv. Ireland.Google Scholar
Franck, F. C, 1958. Discussion, p. 304, in Growth and Perfection of Crystals. Ed. Doremus, R. H., Roberts, R. W., and Turnbull, D., 609 pp. New York.Google Scholar
Ito, T., 1935. On the symmetry of the rhombic pyroxenes. Zeit. Krist., 90, p. 151.Google Scholar
Jagger, T. A. Jr, 1917. Volcanologic investigations at Kilauea. Amer. J. Sci. 4th ser., 44, 161.Google Scholar
Kuno, H., 1955. Ion substitution in the diopside ferropigeonite series of clinopyroxenes. Am. Min., 40, 7093.Google Scholar
Kushiro, I., and Schairer, J. F., 1963. New data on the system Diopside-Forsterite-Silica. Ann. Rept. Geophys. Lab.: Carnegie Inst., Washington, Year Book, 62, 95103.Google Scholar
Miers, H. A., and Isaac, F., 1907. The spontaneous crystallization of binary mixtures. Experiments on salol and betol. Proc. R.Soc., 79, 322–51.Google Scholar
Miers, H. A., and Isaac, F., 1908. The spontaneous crystallization of substances which form a continuous series of mixed crystals. Mixtures of naphthalene and β-naphthol. Trans. Chem. Soc., 93, 927–36.Google Scholar
Muir, I. D., and Long, J. V. P., 1965. Pyroxene relations in two Hawaiian hypersthene bearing basalts. Min. Mag., 34, 358–69.Google Scholar
Muir, I. D., and Tilley, C. E., 1964. Iron enrichment and pyroxene fractionation in tholeiites. Geol. J., 4, 143–56.Google Scholar
Preston, J., 1965. Tertiary feeder dykes in the West of Ireland. Proc. Geol. Soc. London., 1626, 149–50.Google Scholar
Preston, J., 1966. An unusual hourglass structure in augite. Am. Miner. 51, 1227–33.Google Scholar
Roozeboom, H. W. B., 1899. Erstarrungspunkte der Mischkrystalle zweier Stoffe. Zeit. Phys. Chem., 30, 385412.Google Scholar
Yoder, H. S. Jr, and Tilley, C. E., 1962. Origin of basaltic magmas: An experimental study of natural and synthetic rock systems. J. Petrol., 3, 342532.CrossRefGoogle Scholar
Yoder, H. S. Jr, and Schairer, J. F., 1963. Pyroxenes and associated minerals in the crust and mantle. Pyroxene quadrilateral. Ann. Rept. Geophys. Lab.: Carnegie Inst., Washington, Year Book, 62, 8495.Google Scholar