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Magma mixing and metasomatic reaction in silicate-carbonate liquids at the Kruidfontein carbonatitic volcanic complex, Transvaal

Published online by Cambridge University Press:  05 July 2018

L.B. Clarke  and
M.J. Le Bas
L.B. Clarke
Affiliation:
Department of Geology, University of Leicester, LE1 7RH, UK
M.J. Le Bas
Affiliation:
Department of Geology, University of Leicester, LE1 7RH, UK
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Abstract

The Kruidfontein volcanic complex is a Proterozoic collapsed carbonatitic caldera structure, the inner caldera of which is filled with carbonatitic bedded volcaniclastic rocks cut by carbonatite dykes, and the outer with bedded silicate tuffs. As well as numerous fragments of phonolitic pumice in the silicate tuffs, there are unusual banded fragments composed of alternating silicate and carbonate compositions which appear to have been originally glasses, and which give evidence for mechanical mixing of magmas which may originally have been magmas separated by liquid immiscibility. The fragments have also been strongly fenitized with the introduction of K and the replacement of Al by Fe.

Keywords

carbonatiteKruidfonteinSouth Africamagma mixingmetasomatic reaction
Type
Geochemistry and Petrology
Information
Mineralogical Magazine , Volume 54 , Issue 374 , March 1990 , pp. 45 - 56
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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References

Andersen, T. (1984) Lithos, 17, 227-45.CrossRefGoogle Scholar
Bryan, W. B., Finger, L. W., and Chayes, F. (1969) Science, 163, 926-7.CrossRefGoogle Scholar
Carmichael, I. S. E. (1979) Glass and Glassy Rocks. In Evolution of the Igneous Rocks (Yoder, H. S., ed.) 233-44. Princeton Univ. Press, New Jersey.Google Scholar
Clarke, L. B. (1989) Ph.D. thesis, University of Leicester.Google Scholar
Coombs, D. S. (1954) Mineral Mag. 30, 409-27.Google Scholar
Dawson, J. B., Smith, J. V. and Steele, I. M. (1989) J. Geol. 97, 365-72.CrossRefGoogle Scholar
Dingwall, D. B. (1989) Am. Mineral. 74, 333-8.Google Scholar
Haggerty, S. E. (1970) Ann. Rept. Dir. Geophys. Lab. Carnegie Inst. Yearb. 68, 329-30.Google Scholar
Heinrich, E. Win. (1966) The geology of carbonatites. Rand McNally, Chicago.Google Scholar
Le Bas, M. J. (1977) Carbonatite-nephelinite volcanism, Wiley, London.Google Scholar
Le Bas, M. J. (1987) Nephelinites and carbonatites. In Alkaline igneous rocks (Fitton, J. G. and Upton, B. G. J., eds), Geol. Soc. Spec. Publ. 30, 53-83.Google Scholar
Le Maitre, R. W., Streckeisen, A. and Zanettin, B. (1986) J. Petrol. 27, 745-50.Google Scholar
Le Maitre, R. W. (1976) Ibid. 17, 589-637.Google Scholar
Treiman, A. H. and Sehedl, A. (1983) J. Geol. 91, 437-47.CrossRefGoogle Scholar
Verwoerd, W. J. (1967) Geol. Surv. S Africa, Handbook, 6.Google Scholar