Rheology of Naturally Deformed Antigorite Serpentinite : Strain and Strain-Rate Dependence at Mantle-Wedge Conditions
© 2022. The Authors.
| Veröffentlicht in: | Geophysical research letters. - 1984. - 49(2022), 16 vom: 28. Aug., Seite e2022GL098945 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2022
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| Zugriff auf das übergeordnete Werk: | Geophysical research letters |
| Schlagworte: | Journal Article antigorite serpentine deformation mechanisms plate boundary rheology |
| Zusammenfassung: | © 2022. The Authors. 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 |
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| Beschreibung: | Date Revised 05.09.2024 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 0094-8276 |
| DOI: | 10.1029/2022GL098945 |