Abstract
RECENTLY Wallace and Green1 reported the experimental formation of a dolomitic (Ca–Mg) carbonate melt in equilibrium with peridotite minerals in the range 21–30 kbar and 930–1,080 °C. These results confirm earlier deductions that, in the presence of CO2, initial melts from the mantle would be carbonatitic2,3, and extend the conditions of carbonate melt generation. The dolomitic melt composition also endorses earlier observations of quench dolomite after experimental melting of a natural garnet peridotite4. Dolomitic ashes, erupted from volcanoes near the confluence of the Rufunsa and Luangwa rivers in south-east Zambia5,6, offer the nearest analogue to the experimental melt yet reported. Quenched melt droplets in the volcanics now reveal new evidence indicating a mantle source for this natural dolomite liquid. Specifically, I present here results which show that the liquid contains magnesio-chromite crystals (52% Cr2O3) that match those in mantle peri-dotites, kimberlites and lamproites. In contrast with the experimental liquid, the natural dolomitic melt has a low iron content,and high manganese and strontium, with alkalis virtually absent. High potassium activity is recorded, however, in the intensely metasomatized rocks around the main volcanoes. These differences suggest that the mantle source region chemistry differs from the high-sodium source envisaged in the experiments. The Zambian carbonatites thus reveal new aspects of carbonate melt and fluid activity in the Earth's mantle.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Wallace, E. W. & Green, D. H. Nature 335, 343–346 (1988).
Wyllie, P. J. & Huang, W. L. Nature 257, 297–299 (1975).
Eggler, D. H. Geology 4, 787–788 (1976).
Wendlandt R. F. & Mysen, B. O. Am. Miner. 65, 37–44 (1980).
Bailey, D. K. Bull. 5. Geol. Surv. Northern Rhodesia 92 (1960).
Bailey, D. K. in Carbonatites (eds Tuttle, O. F. & Gittings, J. 127–154 (Wiley, New York, 1966).
Woolley, A. R. & Garson, M. S. in African Magmatism and Tectonics (eds Clifford, T. N. & Gass, I. G.) 237–262 (Oliver & Boyd, Edinburgh, 1970).
Tuttle, O. F. & Gittins, J. (eds) Carbonatites (Wiley, New York, 1966).
Bailey, D. K. Geol. Mag. 98, 277–284 (1961).
Bailey, D. K. J. geol. Soc. Lond. 133, 103–106 (1977).
McGetchin, T. R. & Ullrich, G. W. J. geophys. Res. 78, 1833–1853 (1973).
Mercier, J.-C. C. in The Mantle Sample. Proc. 2nd Kimberlite Conf. 197–212 (American Geophysical Union, 1979).
McCallister, R. H., Meyer, H. O. A. & Aragon, R. in The Mantle Sample, Proc. 2nd Kimberlite Conf. 244–248 (American Geophysical Union, 1979).
McGetchin, T. R., Nikhanj, Y. S. & Chodos, A. A. J. geophys. Res. 78, 1854–1869 (1973).
Gittins, J. Nature 335, 295–296 (1988).
Gold, D. P. Miner. Soc. India, IMA Volume 83–91 (1966).
Le Bas, M. J. in Alkaline Igneous Rocks (eds Fitton, J. G. & Upton, B. G. J.) 53–83 (Blackwell, Oxford, 1987).
Smith, J. V. & Dawson, J. B. Phys. Chem. Earth 9 (eds Ahrens, L. H., Dawson, J. B., Duncan, A. R. & Erlank, A. J.) 309–322 (Pergamon, Oxford, 1975).
Haggerty, S. E. in The Mantle Sample, Proc. 2nd Kimberlite Conf. 183–196 (American Geophysical Union, 1979).
Haggerty, S. E. Phys. Chem. Earth 9 (eds Ahrens, L. H., Dawson, J. B., Duncan, A. R. & Erlank, A. J.) 293–308 (Pergamon, Oxford, 1975).
Mitchell, R. H. Trans. geol. Soc. S. Afr. 88, 411–437 (1985).
Bailey, D. K. J. geol. Soc. Lond. 145, 103–105 (1988).
Wendlandt, R. F. & Eggler, D. H. Am. J. Sci. 280, 421–458 (1980).
Olafsson, M. & Eggler, D. H. Earth planet Sci. Lett 64, 305–315 (1983).
Navon, O., Hutcheon, I. D., Rossman, G. R. & Wasserburg, G. J. Nature 335, 784–789 (1988).
Griffin, W. L. & Kresten, P. in Mantle Xenoliths (ed. Nixon, P.H.) 101–106 (Wiley, New York, 1987).
Nixon, P. H. in Mantle Xenoliths (ed. Nixon, P. H. ) 232 (Wiley, New York, 1987).
Nixon, P. H. in Mantle Xenoliths (ed. Nixon, P. H.) 187–193 (Wiley, New York, 1987).
International Geological Map of Africa (CGMW and UNESCO, 1986).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bailey, D. Carbonate melt from the mantle in the volcanoes of south-east Zambia. Nature 338, 415–418 (1989). https://doi.org/10.1038/338415a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/338415a0
This article is cited by
-
Petrography, mineralogy and SIMS U-Pb geochronology of 1.9–1.8 Ga carbonatites and associated alkaline rocks of the Central-Aldan magnesiocarbonatite province (South Yakutia, Russia)
Mineralogy and Petrology (2019)
-
Carbonate inclusions in Lower Cretaceous picrites from the Hončova hůrka Hill (Czech Republic, Outer Western Carpathians): Evidence for primary magmatic carbonates?
International Journal of Earth Sciences (2015)
-
Geochemical patterns and origin of alkaline thermal waters in Central Greece (Platystomo and Smokovo areas)
Environmental Earth Sciences (2013)
-
The high PT stability of apatite and Cl partitioning between apatite and hydrous potassic phases in peridotite: an experimental study to 19 GPa with implications for the transport of P, Cl and K in the upper mantle
Contributions to Mineralogy and Petrology (2012)
-
Calcite-bearing dolomite carbonatite dykes from Veseloe, North Transbaikalia, Russia and possible Cr-rich mantle xenoliths
Mineralogy and Petrology (2007)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
