Preferred Orientations of Mica Bearing Rocks Described by Texture Components

Up to now Texture investigations of phyllosilicates were restricted to pole density measurements ofthe (001) basal plane. Because of the tabular grain shape parallel to the basal plane an axial symmetryof the texture is assumed usually. This assumption was proved for four mica bearing samples bycalculating the ODF from neutron diffraction data. Beside the mica-texture the textures of the othermajor fractions like quartz and feldspar were determined to detect correlation between them. Thetextures are explained by components. Each component is characterised by a preferred orientation orfibre axis, a corresponding spreading and an intensity Iʿ describing the volume fraction of all crystallitesbelonging to the component. The presented component method can be applied to any crystal symmetryand to polyphase materials with overlapped pole figures.