XKS splitting reveals lateral variations of seismic anisotropy across NE Tibet.

Asian lithosphere beneath Qilian–Alxa and Tibetan lithosphere beneath SPGZ–KL-WQL.

KLF-to-WQLF zone may constitute a boundary accommodating lithospheric extrusion.

Decoupling deformation in Qilian while coherent deformation in SPGZ–WQL.

Eastward extrusion of lithospheric blocks dominates deformation in NE Tibet.