Deformation of quartz in an inner shear zone of the Ryoke belt: an example in the Kishiwada area, Osaka Prefecture

The Kawai mylonite zone, an inner shear zone of the Ryoke belt, trends N75°E oblique to the general trend (E-W) of the gneissose granites in the Kishiwada area, Osaka Prefecture. Mylonites were formed under sinistral shear movement and cataclasis was overprinted along the Kawai cataclasite zone within the mylonite zone. Mylonites in the northern part of the cataclasite zone are characterized by the occurrence of P-type (higher T and lower δε/δt type) quartz whereas those in the southern part by S-type (lower T and higher δε/δt type) quartz. This contrast suggests that both mylonites were formed under different deformation environment (T and/or δε/δt) and thereafter juxtaposed together during a fault movement along the cataclasite zone. -from English summary