![70.0 Quasimylonite. NE Diablo Range. Lenses down to micro-lenses (microlithons) of sandstone (light gray) “float” in a matrix of dark gray-brown, sheared mudrock. A few white quartz veins are also present. Shear fractures and slickensides (not visible) on shale surfaces suggest brittle failure and dislocation. “Necking” and elongation of sandstone lenses (e.g., at bottom of image) indicate plastic deformation of the sandstone layers. [Scale on right shows mm divisions.]](../70.0.JPG)
70.0 Quasimylonite. NE Diablo Range. Lenses down to micro-lenses (microlithons) of sandstone (light gray) “float” in a matrix of dark gray-brown, sheared mudrock. A few white quartz veins are also present. Shear fractures and slickensides (not visible) on shale surfaces suggest brittle failure and dislocation. “Necking” and elongation of sandstone lenses (e.g., at bottom of image) indicate plastic deformation of the sandstone layers. [Scale on right shows mm divisions.]