P-wave velocity structure of crust and upper mantle in Northeast China and its control on the formation of mineral and energy

Northeast China, which is located at the composite part of Paleo-Asian ocean and Pacific ocean domains, has undergone multi-stage tectonism. The activity of crust and upper mantle is strong and geological structure is complicated. In this paper, we obtain the three-dimensional P-wave velocity model of northeast China by using P-wave travel times from local and teleseismic events in North and Northeast China. The tomographic resolution is about 80 km. The tomographic images show a very heterogeneous structure in the crust and upper mantle under Northeast China. The velocity structure in the shallow depth (5 km depth) correlates well with the surface geological features: Yanshan and Da Hinggan Ling orogens show high-velocity anomalies and the Bohai Bay and Songliao basin show prominent low-velocity anomalies which extend down to more than 200 km depth. Two low-velocity anomaly belts exist in Northeast China, which are along the Changbai Mountain and Songliao Basin, respectively. Changbai Mountain low-velocity anomaly extends down to about 400 km depth. Mantle Transitional Zone (MTZ) represents high-velocity anomaly which correlates well with the high-velocity Pacific subducted slab stagnating in the MTZ. High resolution tomographic images represent that structural evolution of Northeast China (e. g., magmatism, lithosphere evolution, deep seismicity and volcanism) is related to the upwelling of hot and wet asthenospheric materials in the big mantle wedge above the stagnant Pacific slab. The magmatism of Northeast China provided the source in formation of the minerals and took deep control effect on energy source formation.