The effect of muscovite on the microstructural evolution and rheology of quartzite in general shear

We conducted general shear experiments on synthetic mixtures of quartz and muscovite aggregates at 800 °C 1.5 GPa with 0.1 wt% H2O added in the Griggs apparatus to investigate role content microstructural evolution rheological properties aggregates. Muscovite varied between 0, 5, 10 25% muscovite. Mechanically, sample strengths decrease an increase content. At high strains grains align sub-parallel plane C′- bands commonly observed muscovite-bearing samples. The presence has significant influence amount dynamic recrystallization quartz; pure completely recrystallizes while only ∼5% is dynamically recrystallized similar strains. also a crystallographic preferred orientations (CPO) grain shape (SPO) strains, interpretated deform primarily by basal glide dissolution-precipitation creep. Finally, our mechanical results fit well mixing models, where we estimate may 1–2 orders magnitude faster than conditions near brittle-ductile transition.