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The Nephelinite of Etinde, Cameroons, West Africa

Published online by Cambridge University Press:  01 May 2009

C. E. Tilley
Affiliation:
Department of Mineralogy and Petrology, Cambridge.

Abstract

Re-examination of the nephelinites of Etinde, Cameroons, carrying a composite structured “nepheline” mineral shows that the feldspathoid is a genuine nepheline, in part exhibiting twinned intergrowths, and not a potassic orthorhombic feldspathoid phase. Analysis indicates a composition with a mol. ratio of 3·6. Comparison is made with other nephelines in contrasted host environments.

Type
Articles
Copyright
Copyright © Cambridge University Press 1953

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References

REFERENCES

Adamson, O. J., 1944. The petrology of the Norra Kärr district. Geol. För. Förh. Stockholm, lxvi, 113255.CrossRefGoogle Scholar
Bowen, N. L., 1912. The Binary system: Nephelite-Anorthite. Amer. Journ. Sci., xxxiii, 572.Google Scholar
Bowen, N. L., 1917. The Sodium-Potassium Nephelites. Amer. Journ. Sci., xliii, 130.Google Scholar
Esch, E., 1901. Der Vulkan Etinde in Kamerun und seine Gesteine. Sitzb. Kgl. preuss. Akad. Wiss., Berlin, xii, xviii, 141.Google Scholar
Freudenberg, W., 1906. Geologie und Petrographie des Katzenbuckels im Odenwald. Mitt. Grossh. Bad. Geol. Landesanstalt, v, 1, 1–160, esp. pp. 47–8.Google Scholar
Ippen, J. A., 1902. Ueber einige Ganggesteine von Predazzo. Sitzb. Kaiserl. Akad. Wiss. Wien, cxi, i, 33.Google Scholar
Lacroix, A., 1923. Min. Madagascar, Paris, iii, 65.Google Scholar
Sahama, Th. G., 1952. Leucite, Potash Nepheline and Clinopyroxene from S. W. Uganda and Belgian Congo. Amer. Journ. Sci., Bowen Volume, 460.Google Scholar
Tilley, C. E., 1952. Nepheline Parageneses. Sir Douglas Mawson Anniv. Vol., Hassell Press, Adelaide, 167177.Google Scholar
Troeger, W. E., 1935. Spezielle Petrographie der Eruptivgesteine, Berlin, 254.Google Scholar
Winchell, A. N., and Winchell, H., 1951. Elements of Optical Mineralogy, part ii, 4th Edition, 251.Google Scholar