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Originally published in Science Express on 28 July 2005
Science 9 September 2005:
Vol. 309. no. 5741, pp. 1707 - 1710
DOI: 10.1126/science.1111895
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Reports

Fe-Mg Interdiffusion in (Mg,Fe)SiO3 Perovskite and Lower Mantle Reequilibration

Christian Holzapfel,1*{dagger} David C. Rubie,1 Daniel J. Frost,1 Falko Langenhorst2

Fe-Mg interdiffusion coefficients for (Mg,Fe)SiO3 perovskite have been measured at pressures of 22 to 26 gigapascals and temperatures between 1973 and 2273 kelvin. Perovskite Fe-Mg interdiffusion is as slow as Si self-diffusion and is orders of magnitude slower than Fe-Mg diffusion in other mantle minerals. Length scales over which chemical heterogeneities can homogenize, throughout the depth range of the lower mantle, are limited to a few meters even on time scales equivalent to the age of Earth. Heterogeneities can therefore only equilibrate chemically when they are stretched and thinned by intense deformation.

1 Bayerisches Geoinstitut, University of Bayreuth, D-95440 Bayreuth, Germany.
2 Friedrich-Schiller-Universität Jena, Institut für Geowissenschaften, Burgweg 11, D-07749, Germany.

* Present address: Universität des Saarlandes, Institut für Werkstoffwissenschaft, Funktionswerkstoffe, Postfach 15 11 50, D-66041 Saarbrücken, Germany.

{dagger} To whom correspondence should be addressed. E-mail: c.holzapfel{at}mx.uni-saarland.de

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THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
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D. P. Dobson, M. Alfredson, C. Holzapfel, and J. P. Brodholt (2007)
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