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GEOPHYSICAL RESEARCH LETTERS,
VOL. 33,
L01304,
doi:10.1029/2005GL023887,
2006
Elastic anisotropy of FeSiO3 end-members of the perovskite and post-perovskite phases
Stephen Stackhouse
Department of Earth Sciences, University College London, London, UK
John P. Brodholt
Department of Earth Sciences, University College London, London, UK
G. David Price
Department of Earth Sciences, University College London, London, UK
Abstract
The athermal elastic constants of the perovskite and post-perovskite polymorphs of pure end-member FeSiO3 were calculated from ab initio calculations. We predict that incorporating ten mole percent FeSiO3 together with four mole percent Al2O3 into MgSiO3 reduces the perovskite to post-perovskite phase transition pressure by 5 GPa. Small changes in the seismic properties of
the post-perovskite phase due to the incorporation of iron and alumina are compatible with observations for the lower mantle.
MgSiO3 post-perovskite enriched in fifty percent or more iron may be responsible for ultra-low velocity zones at the base of the
mantle.
Received 23
June
2005;
accepted 30
November
2005;
published 7
January
2006.
Index Terms: 3620 Mineralogy and Petrology: Mineral and crystal chemistry (1042); 3909 Mineral Physics: Elasticity and anelasticity; 8124 Tectonophysics: Earth's interior: composition and state (1212, 7207, 7208, 8105).
Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 99396 bytes)
Citation: Stackhouse, S., J. P. Brodholt, and G. D. Price
(2006),
Elastic anisotropy of FeSiO3 end-members of the perovskite and post-perovskite phases,
Geophys. Res. Lett.,
33,
L01304,
doi:10.1029/2005GL023887.
Copyright 2006 by the American Geophysical Union.
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