Elastic anisotropy of FeSiO 3 end‐members of the perovskite and post‐perovskite phases
2006; American Geophysical Union; Volume: 33; Issue: 1 Linguagem: Inglês
10.1029/2005gl023887
ISSN1944-8007
AutoresStephen Stackhouse, John P. Brodholt, G. D. Price,
Tópico(s)Geological and Geochemical Analysis
ResumoThe athermal elastic constants of the perovskite and post‐perovskite polymorphs of pure end‐member FeSiO 3 were calculated from ab initio calculations. We predict that incorporating ten mole percent FeSiO 3 together with four mole percent Al 2 O 3 into MgSiO 3 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. MgSiO 3 post‐perovskite enriched in fifty percent or more iron may be responsible for ultra‐low velocity zones at the base of the mantle.
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