The broken line in the figure denotes the boundary of the Asian continent before collision Mushroom structure of the lithospheric mantle and its genesis at depth: revisited

Abstract：Analysis of geophysical data shows that there is no evidence for subduction of the Pacific plate beneath the continent of present eastern China except the Jilin-Liaoning (Jiliao) area, Northeast China. The tremendous change that has taken place in eastern China since the Mesozoic did not result from the subduction of the Pacific plate beneath continental China but is a major geological event caused by the reworking of the lithospheric mantle by mushroom structure formed by upwelling of asthenospheric materidals. The upwelling of asthenospheric materials resulted in the formation of a structure of coexistence of the new mantle and remnant mantle, reactivation of the lithosphere, folding of the crust of stable cratons, crustal thinning, repeated occurrence of earthquakes, active magmatism, ground subsidence and formation of vast marginal seas of the western Pacific. However, the thickness of the lithosphere did not decrease, and only the rate of lithospheric thinning decreased owing to the formation of the mushroom structure of the mantle. As a result, the lithospheric structure in the region is notably different from those in its surrounding regions. The region with the mushroom-shaped mantle covers the western Pacific region of the whole of Southeast Asia, including the east-central part of Northeast China, eastern North China, the southeastern margin of South China, Malaysia Peninsula, Indonesia, the Philippine, the Sea of Japan, Yellow Sea, East China Sea, South China Sea, the Caroline basin and the Philippine sea basin. There also exists a huge geodesic ellipsoidal positive anomaly corresponding to the low-velocity lithospheric mantle in the western Pacific region of Southeast Asia, which should be caused by mass surplus at the core-mantle boundary. It and its twin—the negative geodesic ellipsoidal anomaly caused by mass deficiency at the core-mantle boundary in the Indian Ocean-Tibet region—form a deep-level dynamic system controlling the structures of continental China. The age of this dynamic system might be Mesozoic or Late Paleozoic. The mantle circulation between brought about a tremendous change of the lithosphere below the western Pacific of Southeast Asia and drove the northward migration of the Indian plate and uplift of the Qinghai-Tibet Plateau.