Hunt, SA, Walker, AM orcid.org/0000-0003-3121-3255 and Mariani, E (2016) In-situ measurement of texture development rate in CaIrO₃ post-perovskite. Physics of the Earth and Planetary Interiors, 257. pp. 91-104. ISSN 0031-9201
Abstract
The rate of crystallographic preferred orientation (CPO) development during deformation of post-perovskite is crucial in interpreting seismic anisotropy in the lowermost mantle but the stability field of MgSiO3 post-perovskite prevents high-strain deformation experiments being performed on it. Therefore, to constrain the rate of CPO development in post-perovskite, we deformed CaIrO3, a low-pressure analogue of MgSiO3 post-perovskite, in simple shear at 3.2GPa and 400○C to a shear strain (γ) of 0.81. From X-ray diffraction patterns acquired during deformation, we invert for CPO as a function of strain. By comparing the CPO that develops with visco-plastic self-consistent (VPSC) models we constrain the critical resolved shear stresses (CRSS) of the non-primary slip-systems in CaIrO3 to be of order 6 times stronger than the primary [100](010) slip system. This value is significantly less than has been assumed by previous studies and if applicable to MgSiO3 implies that seismic anisotropy in the D′ layer develops slower than has previously been assumed.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/). |
Keywords: | Electron Back-Scatter diffraction (EBSD); Orientation Distribution Function (ODF); Lattice Preferred Orientation (LPO); inverse pole figure; D′ layer |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Funding Information: | Funder Grant number NERC NE/K008803/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 May 2016 11:10 |
Last Modified: | 07 Oct 2018 18:22 |
Published Version: | http://dx.doi.org/10.1016/j.pepi.2016.05.007 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.pepi.2016.05.007 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:99668 |