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Minor and trace element chemistry of carbonates, apatites and magnetites in some African carbonatites

Published online by Cambridge University Press:  05 July 2018

J. B. Dawson ,
I. M. Steele ,
J. V. Smith  and
M. L. Rivers
J. B. Dawson
Affiliation:
Department of Geology and Geophysics, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, UK
I. M. Steele
Affiliation:
Department of Geophysical Sciences, University of Chicago, 5734 S. Ellis Ave, IL 60637, USA
J. V. Smith
Affiliation:
Department of Geophysical Sciences, University of Chicago, 5734 S. Ellis Ave, IL 60637, USA
M. L. Rivers
Affiliation:
Department of Geophysical Sciences and Consortium for Advanced Radiation Sources, University of Chicago, 5734 S. Ellis Ave, Chicago, IL 60637, USA
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Abstract

In calcites and dolomites in seven African carbonatites, SrO, FeO and MnO occur in concentrations from 1 to 2 wt.%, whereas Ce, Y, Cu and Zn occur only at the ppm level. Sr, Ce and Y partition preferentially into calcite relative to co-existing dolomite, whereas Fe and Mn favour dolomite. Sr partitions preferentially into calcite relative to co-exisiting apatite, but the light rare-earth elements partition into apatite. Magnetite from Kerimasi contains up to 13 wt.% MgO and 6 wt.% MnO, extending the known ranges in composition of magnetites from carbonatites.

Keywords

mineral chemistrycarbonatitecarbonateapatitemagnetiteAfrica
Type
Mineralogy
Information
Mineralogical Magazine , Volume 60 , Issue 400 , June 1996 , pp. 415 - 425
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1996

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References

Bailey, D.K. (1989) Carbonate melt from the upper mantle in the volcanoes of south-east Zambia. Nature, 388, 415–8.CrossRefGoogle Scholar
Bailey, D.K. (1993) Carbonate magmas. J.Geol Soc. London, 150, 637–51.CrossRefGoogle Scholar
Davies, K.A. (1956) The geology of part of south-east Uganda.Geol. Surv. Uganda Memoir 8, 76pp. Dawson, J.B. (1964) Carbonatitic volcanic ashes in northern Tanganyika. Bull. VolcanoL, 27, 81–92 Google Scholar
Eriksson, S.C. (1989) Phalaborwa: a saga of magma- tism, metasomatism and miscibility.In Carbonatites(K. Bell, ed.), Unwin Hyman, London, 105—48.Google Scholar
Garson, M.S. (1962) The Tundulu carbonatite ring- complex in southern Nyasaland. Geol. Surv. Nyasaland, Memoir 2, 248 pp.Google Scholar
Gaspar, J.C. and Wyllie, P.J. (1983a) Magnetites in the carbonatite from the Jacupiranga Complex, Brazil. Amer. Mineral., 68, 195–213.Google Scholar
Gaspar, J.C. and Wyllie, PJ. (1983/?) Ilmenite (high Mg, Mn, Nb) in the carbonatites from the Jacupiranga complex, Brazil. Amer. Mineral., 68, 960–71.Google Scholar
Goldsmith, J.R. (1960) Exsolution of dolomite from calcite. J. Geol., 68, 103—9.CrossRefGoogle Scholar
Hogarth, D.D. (1989) Pyrochlore, apatite and amphi- bole: distinctive minerals in carbonatite. In Carbonatites(Bell, K., ed.), Unwin Hyman, London, 105—48.Google Scholar
Le Bas, MJ. (1989). Diversification of carbonatites. In: Carbonatites(Bell, K., ed.) Unwin Hyman, London, 427—47.Google Scholar
Le Bas, M.J. and Srivastava, R.K. (1989) The mineralogy and geochemistry of the Mundwara carbonatite dykes, Sirohi district, Rajasthan, India. Neues Jahrb. Mineral Abh., 160, 207–27.Google Scholar
Le Bas, M.J., Keller, J., Tao, Kejie, Wall, F., Williams, C.T. and Zhang Peishan (1992) Carbonatite dykes at Bayan Obo, Inner Mongolia, China. Mineral. Petrol., 46, 198–228.Google Scholar
Mitchell, R.H. (1978) Manganoan magnesian ilmenite and titanian clinohumite from the Jacupiranga carbonatite, Sao Paulo, Brazil. Amer. Mineral, 63, 544–7.Google Scholar
Morbidelli, L., Beccaluva, L., Brotzu, P., Conte, A., Garbarino, C., Gomes, C.B., Macciiotta, G., Ruberti, E., Scheibe, L.F. and Traversa, G. (1986) Petrological and geochemical studies of alkaline rocks from continental Brazil, 3 Fentization of jacupirangite by carbonatite magmas in the Jacupiranga Complex, SP. Periodico di Mineralogia, 55, 261–95.Google Scholar
Paslick, C., Halliday, A., James, D. and Dawson, J.B. (1995) Enrichment of the continental lithosphere by OIB melts: isotopic evidence from the volcanic province of northern Tanzania. Earth Planet. ScL Letts., 130, 109–26.CrossRefGoogle Scholar
Prins, P. (1972) Composition of magnetites from carbonatites. Lithos, 5, 227–40.CrossRefGoogle Scholar
Quon Shi, H. and Heinrich, E.W. (1966) Abundance and significance of some minor elements in carbonatitic calcites and dolomites. Mineral. Soc. India, Internat. Mineral. Volume(Papers 4th Gen. Meeting), 29–36.Google Scholar
Sheppard, S.M.F. and Dawson, J.B. (1973) ,3C/I2C and D/H isotope variations in “primary” igneous carbonatites. Fortsch. Mineral., 50, 128–9.Google Scholar
Smith, J.V. (1995) Synchrotron X-ray sources: instrumental characteristics. New applications in microanalysis, tomography, absorption spectroscopy and diffraction. The Analyst, 120, 1231–45.CrossRefGoogle Scholar
Van Straaten, P. (1989) Nature and structural relationships of carbonatites from Southwest and West Tanzania. In Carbonatites (Bell, K., ed.)Unwin- Hyman, London, 177—99.Google Scholar
Veen, A.H. van der (1965) Calcite-dolomite intergrowths in high-temperature carbonate rocks. Amer. Mineral., 50, 2070–7.Google Scholar
Verwoerd, W.J.(1967) The carbonatites of South Africa and South West Africa. Geol. Surv. S. Africa Handbook^, 6, 452 pp.Google Scholar
Wallace, M.E. and Green, D.H. (1988) An experimental determination of primary carbonatite magma composition. Nature, 335, 343–6.CrossRefGoogle Scholar