Microstructures of Mama Shear Zone: a) S_myl/C_n+2 fabric of a mylonite; b) ultramylonitic foliation S_myl; c) S_myl/C_n+2 fabric of a mylonite, marked by the preferred orientation of quartz ribbons with serrated grain boundaries and an undulose extinction, and by biotite porphyroclasts with a sigma shape consistent with a sinistral sense of shear; d) amoeboid quartz grains; e) asymmetric grain with lobate borders; f) asymmetric alkali feldspar grains with bulges; g) quartz grains with grain boundaries at 120 °; h) porphyroclasts and multi-grain composite clasts embedded in finely recrystallized matrix, and alternating beds in an ultramylonite granodiorite.