Rheology of Naturally Deformed Antigorite Serpentinite: Strain and Strain-Rate Dependence at Mantle-Wedge Conditions.

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-pr

SUBMITTER: Tulley CJ 

PROVIDER: S-EPMC9539589 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature