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Further Considerations on the Deposition of the Middle Cambrian Manganese Carbonate Beds of Wales and Newfoundland

Published online by Cambridge University Press:  01 May 2009

P. A. Mohr
Affiliation:
Geophysical Observatory, P.O. Box 399, Addis Ababa, Ethiopia.
R. Allen
Affiliation:
Dept. of Mineralogy and Petrology, Downing Place, Cambridge.

Abstract

The succession of individual coloured bands in two manganese ore specimens has been analysed for eight trace elements, and has revealed some long-term chemical variations of possible regional extent throughout the period of ore deposition. Previous work on the distribution of elements between the three types of coloured ore banding is confirmed, and new data on the equivalent coloured bands of the contemporaneous Newfoundland manganese bed reveal an essential chemical, as well as lithological, identity of the two rocks. The effects of weathering and oxidation on ore geochemistry are discussed.

Type
Articles
Copyright
Copyright © Cambridge University Press 1965

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References

REFERENCES

Dale, N. C., 1915. The Cambrian manganese deposits of Conception and Trinity Bays, Newfoundland. Proc. Amer. Phil. Soc., 54, 371456.Google Scholar
Dewey, H., and Dines, H. G., 1923. Tungsten and manganese ores (3rd ed.) Mem. Geol. Surv, Min. Resources.Google Scholar
Goldschmidt, V. M., 1954. Geochemistry. Cambridge Univ. Press.Google Scholar
Mohr, P. A., 1955. Unpublished Ph.D. thesis, Univ. Manchester.Google Scholar
Mohr, P. A. 1956 a. Trace element distribution in a garnet-chlorite rock from Foel Ddu, near Harlech, Merionethshire. Miner. Mag., 31, 319327.Google Scholar
Mohr, P. A. 1956 b. A geochemical study of the Lower Cambrian manganese ore of the Harlech Dome, North Wales. XX Int. Geol. Cong. Mexico City, Manganese Symposium, 5, 273289.Google Scholar
Mohr, P. A. 1964. Genesis of the Cambrian manganese carbonate rocks of North Wales. J. Sed. Pet., 34, 819829.Google Scholar
Mohr, P. A. 1966. The Cambrian manganese carbonate rocks of Newfoundland and Wales: the source of the manganese and the conditions of its deposition (in press).Google Scholar
Rankama, K., and Sahama, T. G., 1950. Geochemistry. Univ. Chicago Press.Google Scholar
Servant, J., 1956. Les gisements et indices de manganese de l'Afrique Occidentale Francaise. XX Int. Geol. Cong. Mexico City, Manganese Symposium, 2, 89114.Google Scholar
Woodland, A. W., 1939. The petrography and petrology of the Lower Cambrian manganese ore of West Merionethshire. Quart. J. geol. Soc. Lond., 95, 136.CrossRefGoogle Scholar