Deformation mechanisms of antigorite serpentinite at subduction zone conditions determined from experimentally and naturally deformed rocks

摘要: Abstract We performed deformation-DIA experiments on antigorite serpentinite at pressures of 1–3.5 GPa and temperatures between 400 650 °C, bracketing the stability under subduction zone conditions. For each set pressure–temperature (P–T) conditions, we conducted two runs strain rates 5 × 10 − 1 4 s . complemented our study with a sample deformed in Griggs-type apparatus 400 °C ( Chernak Hirth, 2010 ), natural samples from Cuba Alps blueschist/eclogitic Optical transmission electron microscopies were used for microstructural characterization determination deformation mechanisms. Our observations experimentally prior to breakdown show that is dominated by cataclastic flow observable but minor contribution plastic (microkinking (001) gliding mainly expressed stacking disorder mainly). In contrast, naturally samples, structures are dominant (stacking disorder, kinking, pressure solution), also perceptible brittle deformation. When dehydration occurs experiments, plasticity increases coupled local embrittlement attribute dehydration. dehydrating collected Alps, observed suggesting may contribute intermediate-depth seismicity. results thus semibrittle operates within above field antigorite. However, recorded was likely acquired low rates. document corrugated structure controls accommodation mechanisms preferred inter- intra-grain cracking along both b. rheology zones partly controlled presence fluids, which can percolate exhumation channel via deformation-induced interconnected porosity.