Neutron texture study of a natural gneiss mylonite affected by two phases of deformation

The texture of a mylonitic gneiss sample from a major shear zone in the Alps was studied using the texture diffractometer SV7-b at the Forschungszentrum Julich. Pole figure data processing yielded complete textures for several constituent mineral phases (quartz, chlorite, mica). In combination with orientation analysis of grain boundaries, this allowed us to separate two successive stages of deformation which occurred in different kinematic frameworks, giving important information on deep-seated tectonic processes during the formation of the Alps.