Neutronographic Fabric Analysis of Quartz in Naturally Deformed Gneiss
The crystalline preferred orientations of quartz grains in pencil gneiss from the Erzgebirge (southern GDR) are studied by means of neutron time-of-flight diffraction. A single component texture has been found where the trigonal axes are parallel to the tectonic a-direction. In the quartz c-axis pole figure strong maxima at tectonic ±a are connected by a girdle of weaker intensity being not found in U-stage measurements. From the comparison with experimentally deformed quartzites and model calculations the approximate formation conditions of the given pencil gneiss could be deduced.