Crystal preferred orientation (CPO) of high pressure metamorphic rocks is an important contributor to seismic anisotropy in the subduction interface and continental crust. However, the mechanisms of deformation and CPO development, as well as the effect of CPO patterns on the seismic anisotropies remain not fully solved. By analyzing the microstructures, CPOs and seismic properties of the high pressure rocks from the Central Qiangtang metamorphic belt in the northern Tibetan Plateau, we found that the mineral CPOs (e.g., omphacite and amphibole) are developed dominantly by non-dislocation based deformation mechanisms in the eclogites and amphibolites, while quartz and phengite CPOs are primarily formed by dislocation creep in the garnet-quartz-mica schists. The variations of CPO patterns are mainly controlled by the strain geometry and/or strain magnitude, which also regulate the first-order symmetry patterns of seismic anisotropies among samples. Besides, amphibole enrichment can remarkably increase the anisotropies and decrease the velocities of seismic waves in the eclogite‒amphibolite suite. A combination of seismic parameters such as Vp, Vs, Vp/Vs ratio, intensities and symmetries of P-wave anisotropy (AVp) and shear wave splitting (AVs), and P- or S-wave reflection coefficients can be used to discriminate eclogites, amphibolites and their garnet-quartz-mica schists country rocks at depth when high resolution seismic methods can be applied. Notably, amphibolite and garnet-quartz-mica schists showing moderate-to-large AVp and max. AVs can make considerable contributions to field-observed crustal anisotropy near the strike-slip continental shear zones or mantle wedge anisotropy in the subduction zones.

高压变质岩的晶体择优取向（CPO）是俯冲界面和大陆壳地震各向异性的重要因素。但是，变形和CPO发育的机理，以及CPO模式对地震各向异性的影响仍未完全解决。通过分析青藏高原北部Qian塘中部变质带高压岩石的微观结构，CPOs和地震特性，我们发现矿物CPOs（如绿辉石和闪石）主要由非位错变形机制形成。榴辉岩和角闪石，而石英和辉石的CPO主要是由石榴石-石英-云母片岩中的位错蠕变形成的。CPO模式的变化主要受应变几何形状和/或应变大小控制，这也调节了样本之间地震各向异性的一阶对称模式。此外，闪石富闪石富集可以显着增加各向异性，降低地震波的速度。地震参数（例如Vp，Vs，Vp / Vs比，P波各向异性（AVp）和剪切波分裂（AVs）的强度和对称性以及P波或S波反射系数）的组合可用于区分榴辉岩可以应用高分辨率地震方法时，可在深处形成闪石，闪石和其石榴石-石英-云母片岩。值得注意的是，角闪石和石榴石-石英-云母片岩表现出中等至大的AVp和最大。