The Structural Evolution of an Orthogneiss-fold Within the Reitzenhainer Rotgneisstruktur (Erzgebirge Mts., GDR)
The crystallographic preferred orientations of quartz in gneiss taken from different spots of a recumbent fold structure in the Erzgebirge Mts. (southern GDR) are studied by means of neutron time-of-flight diffraction. A single component texture has been found for all specimens, with quartz c-axes parallel to the tectonic a-direction. The variations in texture sharpness are related to different deformation conditions of the samples. A fabric rotation of 30° has been found from the limb to the crest of the fold on the basis of () and () pole figures. The basal pole figures of quartz derived from an ODF analysis compared well with optical U-stage measurements. The determined fabrics are discussed taking into account model calculations of experimentally deformed quartzites and geological informations.