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Carbonates of the magnesite–siderite series from four carbonatite complexes

Published online by Cambridge University Press:  05 July 2018

H. A. Buckley
Affiliation:
Department of Mineralogy, British Museum (Natural History), Cromwell Road, London SW7 5BD
A. R. Woolley
Affiliation:
Department of Mineralogy, British Museum (Natural History), Cromwell Road, London SW7 5BD

Abstract

Carbonates of the magnesite-siderite series have been found and analysed in carbonatites from the Lueshe, Newania, Kangankunde, and Chipman Lake complexes. This series has been represented until now only by a few X-ray identifications of magnesite and three published analyses of siderite and breunnerite (magnesian siderite). Most of the siderite identified in carbonatites in the past has proved to be ankerite, but the new data define the complete solid-solution series from magnesite to siderite. They occur together with dolomite and ankerite and in one rock with calcite. The magnesites, ferroan magnesites and some magnesian siderites may be metasomatic/hydrothermal in origin but magnesian siderite from Chipman Lake appears to have crystallized in the two-phase calcite + siderite field in the subsolidus CaCO3-MgCO3-FeCO3 system. Textural evidence in Newania carbonatites indicates that ferroan magnesite, which co-exists with ankerite, is a primary liquidus phase and it is proposed that the Newania carbonatite evolved directly from a Ca-poor, Mg-rich carbonatitic liquid generated by partial melting of phlogopite-carbonate peridotite in the mantle at pressures >32 kbar.

Type
Non-silicate Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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References

Amundsen, H. E. F. (1987) Evidence for liquid immiscibility in the upper mantle. Nature, London, 327, 692-5.CrossRefGoogle Scholar
Brey, G., Brice, W. R., Ellis, D. J., Green, D. H., Harris, K. L. and Ryabchikov, I. D. (1983) Pyroxene-carbonate reactions in the upper mantle. Earth Planet. Sci. Lett. 62, 63-74.CrossRefGoogle Scholar
Byrnes, A. P. and Wyllie, P. J. (1981) Subsolidus and melting relations for the join CaCO3–MgCO3 at 10 kbar. Geochim. Cosmochim. Acta, 45, 321-8.CrossRefGoogle Scholar
Deer, W. A., Howie, R. A. and Zussman, J. (1962) Rock-forming minerals, 5. Non-silicates, Longmans, London, 371 pp.Google Scholar
Eggler, D. H. (1989) Carbonatites, primary melts, and mantle dynamics. In Carbonatites: genesis and evolution (Bell, K., ed.) 561-79. Unwin Hyman, London.Google Scholar
Emeleus, C. H. (1964) The Gronnedal-Ika alkaline complex, South Greenland. The structure and geological history of the complex. Meddel. om Gronland, 172 (3), 1-75.Google Scholar
Garson, M. S. (1965) Carbonatite and agglomerate vents in the western Shire Valley. Mem. Geol. Surv. Malawi, 3, 167 pp.Google Scholar
Garson, M. S. and Smith, W. Campbell (1958) Chilwa Island. Ibid. 1, 1-127.Google Scholar
Goldsmith, J. R. (1983) Phase relations of rhombohedral carbonates. In Carbonates: mineralogy and chemistry (Reeder, R. J., ed.. Reviews in Mineralogy, 11. Min. Soc. Am., 4976.CrossRefGoogle Scholar
Goldsmith, J. R. and Heard, H. C. (1961) Subsolidus phase relations in the system CaCO3-MgCO3 . J. Geol. 69, 45-74.CrossRefGoogle Scholar
Hornig, I. (1988) Spurenelementunterssuchungen an Karbonatiten mit hilfe der ICP-Atomemissionsspektroskopie. Doctoral Dissertation, Albert-Ludwigs-Universitat, Freiburg i.Br. 238 pp.Google Scholar
Irving, A. J. and Wyllie, P. J. (1975) Subsolidus and melting relations for calcite, magnesite and the join CaCO3-MgCO3 to 36 kb. Geochim. Cosmochim. Acta, 39, 35-53.CrossRefGoogle Scholar
Kapustin, Yu. L. (1980) Mineralogy of carbonatites. Amerind Publishing, New Delhi, 259 pp.Google Scholar
Maravic, H. V. and Morteani, G. (1980) Petrology and geochemistry of the carbonatite and syenite complex of Lueshe (N. E. Zaire). Lithos, 13, 159-70.CrossRefGoogle Scholar
Meyer, A. and Bethune, P. de (1958) La carbonatite Lueshe (Kivu). Bull. Serv. Geol. Congo Belge, 8 (5), 119 and 1-12.Google Scholar
Nash, W. P. (1972) Mineralogy and petrology of the Iron Hill carbonatite complex, Colorado. Bull. Geol. Soc. Am. 83, 1361-82.CrossRefGoogle Scholar
Olafsson, M. and Eggler, D. H. (1983) Phase relations of amphibole, amphibole-carbonate, and phlogopite-carbonate peridotite: petrologic constraints on the asthenosphere. Earth Planet. Sci. Lett. 64, 305-15.CrossRefGoogle Scholar
Rosenberg, P. E. (1967) Subsolidus relations in the system CaCO3-MgCO3-FeCO3 between 350° and 550°. Am. Mineral. 52, 787-96.Google Scholar
Sage, R. P. (1985) Geology and carbonate-alkalic rock complexes of Ontario: Chipman Lake area, Districts of Thunder Bay and Cochrane. Study. Ont. Geol. Surv. 44, 1-40.Google Scholar
Samoilov, V. S. (1984) Geochemistry of carbonatites. Moskva: Izdvo Nauka.Google Scholar
Viladkar, S. G. and Wimmenauer, W. (1986) Mineralogy and geochemistry of the Newania carbonatite-fenite complex, Rajasthan, India. Neues Jahrb. Mineral. Abh. 156, 1-21.Google Scholar