mica gneiss
1.This study recognized that original rocks of the felsic metamorphic rocks from a key horizon (termed K and K_S) in Guangchangling Archean Banded Iron Formation are tuffaceous intermediate acidic volcanic lava for biotite-quartz-albite gneiss (K) and tuffaceous sedimentary rock for garnet-mica-quartz schist (K_S) respectively.
