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A Suspected Spilitic Rock from the Lower Cambrian Manganese Shale Group of the Harlech Dome, North Wales

Published online by Cambridge University Press:  01 May 2009

P. A. Mohr
P. A. Mohr
Affiliation:
Geophysical Observatory, Addis Ababa, Ethiopia.
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Abstract

Mineral and chemical evidence suggest that an unusual rock from the Upper Manganese Shales of Diphwys is of spilitic origin, despite certain geochemical anomalies. Some similarities of the rock to the shales themselves are only superficial, and a metasomatic origin is precluded; the rock is also very distinct from the “greenstone” sills of the region.

Type
Articles
Information
Geological Magazine , Volume 99 , Issue 3 , June 1962 , pp. 265 - 272
Copyright
Copyright © Cambridge University Press 1962

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References

REFERENCES

Amstutz, G. C., 1954. Geologie und Petrographie der Ergussgesteine im Verrucano des Glarner Freiberges. Published doctorate thesis. Zurich.Google Scholar
Barth, T. F. W., 1955. Presentation of Rock Analyses. J. Geol., 63, 348–363.Google Scholar
Battey, M. H., 1956. The Petrogenesis of a Spilitic Rock Series from New Zealand. Geol. Mag., 93, 89–110.Google Scholar
Davies, R. G., 1956. The Pen-y-gader Dolerite and its Metasomatic effects on the Llyn-y-gader Sediments. Geol. Mag., 93, 153–172.CrossRefGoogle Scholar
Gilluly, J., 1935. Keratophyres of eastern Oregon, and the spilite problem. Amer. J. Sci., 29, 225–252, 336–352.CrossRefGoogle Scholar
Lane, A. C., 1911. The Keweenaw series of Michigan. Michigan geol. Surv. Publ., 6.Google Scholar
Lokka, L., 1934. Neure chemische Analysen von finischen Gesteinen. Bull. Comm. geol. Finlande, 105, 1–64.Google Scholar
Matley, C. A., and Wilson, T. S., 1946. The Harlech Dome, North of the Barmouth Estuary. Quart. J. geol. Soc. Loud., 102, 1–40.Google Scholar
Mohr, P. A., 1955. A geochemical study of the Lower Cambrian Manganese Shale Group sediments of the Harlech Dome, North Wales.Un published thesis. Unpublished Manchester University.Google Scholar
Mohr, P. A., 1956. A geochemical study of the Lower Cambrian Manganese Ore of the Harlech Dome, North Wales. XXInt. geol. Cong., Mexico City 1956. Symposium on manganese deposits, 5, 273–289.Google Scholar
Mohr, P. A., 1959. A geochemical study of the shales of the Lower Cambrian Manganese Shale Group of the Harlech Dome, North Wales. Geochim. et Cosmochim. Acta, 17, 186–200.Google Scholar
Nanz, R. H., 1953. Chemical composition of Pre-Cambrian slates with notes on the geochemical evolution of lutites. J. Geol., 61, 51–64.CrossRefGoogle Scholar
Nicholls, G. D., 1959. Autometasomatism in the Lower Spilites of the Builth Volcanic Series. Quart. J. geol. Soc., Loud., 114, 137–162.CrossRefGoogle Scholar
Park, C. F., 1946. Spilite and Manganese problems of the Olympic Peninsula, Washington. Amer. J. Sci., 244, 305–323.CrossRefGoogle Scholar
Sundius, N., 1930. On the spilitic rocks6. Geol. Mag., 67, 1–17.Google Scholar
Turner, F. J., and Verhoogen, J., 1960. Igneous and Metamorphic Petrology (2nd edition). McGraw-Hill.Google Scholar