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Published Online July 28, 2005
Science DOI: 10.1126/science.1111895

Reports

Submitted on March 7, 2005
Accepted on July 19, 2005

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

Christian Holzapfel 1*, David C. Rubie 2, Daniel J. Frost 2, Falko Langenhorst 3

1 Bayerisches Geoinstitut, University of Bayreuth, D-95440 Bayreuth, Germany; present address: Universität des Saarlandes, Institut für Werkstoffwissenschaft, Funktionswerkstoffe, Postfach 15 11 50, D-66041 Saarbrücken, Germany.
2 Bayerisches Geoinstitut, University of Bayreuth, D-95440 Bayreuth, Germany.
3 Friedrich-Schiller-Universität Jena, Institut für Geowissenschaften, Burgweg 11, D-07749, Germany.

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

Fe-Mg interdiffusion coefficients for (Mg,Fe)SiO3 perovskite have been measured at pressures of 22-26 GPa and temperatures between 1973 and 2273 K. 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 the Earth. Heterogeneities can therefore only equilibrate chemically when they are stretched and thinned by intense deformation.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
The Upper Mantle and Transition Zone.
D. J. Frost (2008)
Elements 4, 171-176
   Abstract »    Full Text »    PDF »
Grain-boundary enrichment of iron on magnesium silicate perovskite.
D. P. Dobson, M. Alfredson, C. Holzapfel, and J. P. Brodholt (2007)
European Journal of Mineralogy 19, 617-622
   Abstract »    Full Text »    PDF »


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Science. ISSN 0036-8075 (print), 1095-9203 (online)