Evaluating quartz crystallographic texture strengths using classic eigenvalue methods

During crystal-plastic deformation, crustal rocks develop crystallographic preferred orientations or ‘textures’. When plotted on a hemispheric pole figure, the individual orientations of crystallographic axes from such rocks typically define a non-random distribution where the ‘strength’ of maxima can provide approximations of strain intensity (Lister and Hobbs, 1980). While it is practical for textures to be assessed qualitatively, quantitative texture strength measurements are useful for understanding the evolution of microstructures with increasing strain, and may be essential to quantifying rheological weakening in the lithosphere