Self-diffusion of oxygen and silicon in MgSiO3 perovskite

被引：47

作者：

Dobson, David P. ^{[1
]}

Dohmen, Ralf ^{[2
]}

Wiedenbeck, Michael ^{[3
]}

机构：

[1] UCL, Dept Earth Sci, London WC1E 6BT, England

[2] Ruhr Univ Bochum, Inst Geol Mineral & Gepohys, D-44801 Bochum, Germany

[3] Geoforschungszentrum Potsdam, D-14473 Potsdam, Germany

来源：

EARTH AND PLANETARY SCIENCE LETTERS | 2008年 / 270卷 / 1-2期

关键词：

MgSiO3; perovskite; O diffusion; Si diffusion; lower mantle; chemical equilibration; high-pressure;

D O I：

10.1016/j.epsl.2008.03.029

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

We present results of simultaneous measurements of self-diffusion of oxygen and silicon in magnesium silicate perovskite. Oxygen diffusion is similar to 2 orders of magnitude faster than Si self-diffusion and Fe-Mg interdiffusion in perovskite, with D(0) = 9.16 x 10(-4) (+0.16/-9.2 X 10(-6)) m(2)/s and Q = 501 +/- 80 kJ/mol at 25 GPa. Despite this high 0 diffusivity, however, the electrical conductivity of the lower mantle will be dominated by electronic conduction and the present-day core is likely to be out of redox equilibrium with the mantle. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：125 / 129

页数：5

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