Tulley, CJ, Fagereng, Å, Ujiie, K et al. (3 more authors) (2022) Rheology of Naturally Deformed Antigorite Serpentinite: Strain and Strain‐Rate Dependence at Mantle‐Wedge Conditions. Geophysical Research Letters, 49 (16). ISSN 0094-8276
Abstract
Antigorite serpentinite is expected to occur in parts of subduction plate boundaries, and may suppress earthquake slip, but the dominant deformation mechanisms and resultant rheology of antigorite are unclear. An exhumed plate boundary shear zone exposed near Nagasaki, Japan, contains antigorite deformed at 474°C ± 30°C. Observations indicate that a foliation defined by (001) crystal facets developed during plate-boundary shear. Microstructures indicating grain-scale dissolution at high-stress interfaces and precipitation in low-stress regions suggest that dissolution-precipitation creep contributed to foliation development. Analysis of crystal orientations indicate a small contribution from dislocation activity. We suggest a frictional-viscous rheology for antigorite, where dissolution-precipitation produces a foliation defined by (001) crystal facets and acts to resolve strain incompatibilities, allowing for efficient face-to-face sliding between facets. This rheology can not only explain aseismic behavior at ambient plate boundary conditions, but also some of the contrasting behaviors shown by previous field and laboratory studies.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | Antigorite serpentine; plate boundary; deformation mechanisms; rheology |
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: | 26 Sep 2022 08:57 |
Last Modified: | 26 Sep 2022 08:57 |
Status: | Published |
Publisher: | American Geophysical Union (AGU) |
Identification Number: | 10.1029/2022gl098945 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:190742 |