“…Seismic low‐velocity (low‐ V ) anomalies in the lower crust beneath the northeastern Tibetan Plateau have been revealed by P wave tomography [e.g., Tian et al , ; Wang et al , ; J. Wang et al , ; Cheng et al , ], surface wave and ambient noise tomography [e.g., Zhang et al , ; Yang et al , ; Jiang et al , ; Li et al , ; Bao et al , ], and active‐source seismic profiling [e.g., Liu et al , ; Zhang et al , ]. Magnetotelluric and gravity observation results indicate that a high‐conductivity and low‐density layer exists in the lower crust beneath the northeastern Tibetan Plateau [e.g., Tang et al , ; Zhao et al , ; Xiao et al , ; X. Wang et al , ]. These results suggest the existence of a weak zone in the lower crust beneath the northeastern Tibetan Plateau, which may argue for the geodynamic model of lower crustal ductile flow [ Royden et al , ; Clark and Royden , ].…”