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Nowacki, AJ orcid.org/0000-0001-7669-7383, Walker, AM orcid.org/0000-0003-3121-3255, Wookey, J et al. (1 more author) (2013) Evaluating post-perovskite as a cause of D′′ anisotropy in regions of palaeosubduction. Geophysical Journal International, 192 (3). pp. 1085-1090. ISSN 0956-540X
Abstract
Seismic anisotropy in the Earth's lowermost mantle (D′′) is often attributed to the alignment of MgSiO3 post-perovskite (ppv) by the movement of dislocations in response to mantle flow. However, ppv's plastic yield surface is not known; nor do we know if this is the main deformation mechanism. We make use of a heterogeneous, generally anisotropic model of elasticity in D′′ derived from a 3-D model of mantle flow, which is obtained by inversion of geophysical observables. Unlike previous approaches, completely general, 3-D flow and full anisotropy are permitted, yielding more information to compare with observations than has been possible before. We model observations of anisotropy in D′′ by calculating the shear wave splitting predicted in ScS waves for a series of models of ppv plasticity. We find that observations in regions of the lowermost mantle beneath subduction zones are best fit by a model which accommodates slip on (010). Our results show that, within one standard deviation, slip on (010)—or a mechanism giving the same style of anisotropy—explains D′′ anisotropy beneath these regions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2013, Oxford University Press. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | Mantle processes; Creep and deformation; Seismic anisotropy; Dynamics of lithosphere and mantle; Rheology: mantle |
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) |
Depositing User: | Symplectic Publications |
Date Deposited: | 09 Jul 2019 12:39 |
Last Modified: | 12 Jul 2019 14:24 |
Published Version: | http://dx.doi.org/10.1093/gji/ggs068 |
Status: | Published |
Publisher: | Oxford University Press |
Refereed: | Yes |
Identification Number: | 10.1093/gji/ggs068 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:103652 |
Available Versions of this Item
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Evaluating post-perovskite as a cause of D" anisotropy in regions of palaeosubduction. (deposited 30 Jul 2014 11:17)
- Evaluating post-perovskite as a cause of D′′ anisotropy in regions of palaeosubduction. (deposited 09 Jul 2019 12:39) [Currently Displayed]