Microstructure and seismic properties of amphibole-rich rocks from the deep crust in southern Tibet

Abstract The crust of southern Tibet shows strong azimuthal and radial seismic anisotropies. However, their origin has remained ambiguous. Here we characterized the composition, microstructure, properties amphibole-rich deep-crust xenoliths exhumed rocks from a terrane in Tibet. show typical magmatic textures have amphiboles with homogenous chemical low intracrystalline deformation, but crystallographic preferred orientations (CPOs). We interpret these CPOs as products rotation non-equant amphibole crystals deforming magma. amphibolites display evidence for deformation by dislocation creep. Plagioclase all samples nearly random CPOs. calculated studied indicate that is likely major contributor to deep-crustal anisotropies observed do not necessarily record solid-state flow. They may also result flow large synkinematic mafic plutons.