Contrasting Crustal Rheology and Seismicity in Northeast China: Far‐Field Responses to the Pacific Plate Subduction

Abstract The westward subduction of the Pacific plate has induced lithosphere weakening, intraplate volcanism, thermal and compositional variation in the East Asian continent since the Mesozoic. However, how the intracontinental deformation corresponds to this subduction‐induced lithospheric architecture remains enigmatic. Here we employ an integrated geophysical‐petrological approach to explore the lithospheric structure, thermal regime, and rheology beneath Northeast (NE) China, constrained by seismicity distribution. We find significant lithospheric thinning on the eastern side of the North‐South Gravity Lineament (NSGL). We also identify a cold, dry, and rheologically strong crust west of the NSGL, contrasting with a hot, wet, and rheologically weak crust to the east. We confirm that the NSGL potentially marks a tectonic boundary, influenced by continental contraction and orogeny during the Mongol‐Okhotsk Ocean closure in the west and the hydrous upwelling of the subducted Pacific slab in the east.