Deformation Microstructures of Phyllite in Gunsan, Korea, and Implications for Seismic Anisotropy in Continental Crust

Muscovite is a major constituent mineral in the continental crust that exhibits very strong seismic anisotropy. alignment rocks can significantly affect magnitude and symmetry of In this study, deformation microstructures muscovite-quartz phyllites from Geumseongri Formation Gunsan, Korea, were studied to investigate relationship between muscovite chlorite fabrics strongly deformed anisotropy observed crust. The [001] axes aligned subnormal foliation, while [100] [010] subparallel foliation. distribution quartz c-axes indicates activation basal<a>, rhomb<a> prism<a> slip systems. For albite, most samples showed (001) or (010) poles calculated anisotropies based on lattice preferred orientation modal compositions range 9.0–21.7% for P-wave 9.6–24.2% maximum S-wave Our results indicate composition It was found coexistence contributes constructively when their are same direction.