Fig. 3

Polished surface of a hand-sample of a deformed sandstone lens from the fault core zone. The deformation is marked by cleavage planes, quartz-calcite extension veins and shear planes. Cleavage planes correspond to pressure solution surfaces (stylolites) and define a foliation which density increases toward the shear planes bordering the sandstone lens. Newly-formed phyllosilicates (white mica and chlorite) are concentrated along the cleavage and shear planes