Shear response of Fe-bearing MgSiO3 post-perovskite at lower mantle pressures |
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Authors: | Arnaud METSUE Taku TSUCHIYA |
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Institution: | *1Geodynamics Research Center, Ehime University, Ehime, Japan. |
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Abstract: | We investigate the shear response of possible slip systems activated in pure and Fe-bearing MgSiO3 post-perovskite (PPv) through ab initio generalized stacking fault (GSF) energy calculations. Here we show that the 100](001) slip system has the easiest response to plastic shear among ten possible slip systems investigated. Incorporation of Fe2+ decreases the strength of all slip systems but does not change the plastic anisotropy style. Therefore, pure and Fe-bearing MgSiO3 PPv should demonstrate similar LPO patterns with a strong signature of the 100](001) slip system. An aggregate with this deformation texture is expected to produce a VSH > VSV type polarization anisotropy, being consistent with seismological observations. |
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Keywords: | ab initio density functional computation generalized stacking fault theory seismic anisotropy earth’ s D'''' layer post-perovskite |
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