Episodic Crustal Deformation of Northeastern North China Craton and Its Adjacent Areas: New Constraints from Receiver Function Analysis

Abstract The northeastern North China craton (NCC) has undergone strong crustal deformation and magmatic activities since the Late Mesozoic. To understand the mechanism of the complex tectonic evolution beneath the northeastern NCC and its adjacent areas, the crustal thickness, VP/VS ratio and crustal anisotropy obtained from P-to-S receiver functions are used to provide critical constraints on crustal deformation associated with regional compression and extension. We employed the H−κ−c stacking method to obtain the crustal thickness, VP/VS ratio, and crustal anisotropy at a total of 150 stations deployed by the ChinArray Phase III. The observed crustal thickness varies from 29.9 to 41.7 km with the trending of gradual increase from east to west in the study area. The VP/VS ratio presents lateral heterogeneity but is negatively correlated with the crustal thickness. Most high-VP/VS ratios (>1.81) are calculated beneath the Chifeng and Dalinor volcano (CDV) regions, which implies the more mafic crustal composition. The estimated fast polarization direction (FPD) from the Pms phase splitting shows distinct different patterns in this study area. The variation of the crustal thickness from thicker to thinner and the FPD from east–west to northwest–southeast beneath the southwestern and northeastern Yanshan Mountain would be related to the crustal deformation changing from the north–south compression to the subsequently northwest–southeast back-arc extension. The rotated FPD beneath the Liaodong uplift region would be controlled by the strike-slip shear motion of the Tanlu fault. In addition, we propose that the high-VP/VS ratio and FPD roughly parallel to the outer sub-boundaries of the volcanic rocks beneath the CDV region might result from the eruption and migration of the magma driven by the mantle upwelling.