Crustal thickness and Poisson’s ratio of orogenic belts in northern North China Craton using teleseismic receiver functions

The thickness and Poisson’s ratio of crust of the North China Craton （NCC） are of great significance to the study of lithospheric evolution of the North China Craton. We collected receiver functions from 115 broadband seismic stations and six very broadband seismic stations on the Taihang-Yanshan orogenic belt and its adjacent areas in the northern North China Craton recorded from October 2006 to September 2009. First we used predictive deconvolution method to eliminate the influence of sedimentary on receiver function waveform. Then the effects of S wave azimuthal anisotropy and interfaces dipping were corrected by using H-κ-c stacking method. Finally, the thickness and Poisson’s ratio of research area were obtained. Our results are featured by lateral variation. The crust thickness in the research area is thick in the western block and thin in the eastern block, and is highly correlated to the topography, which is consistence with Airy isostasy. The low Poisson’s ratio of western block represent relative stability of the crust, the distribution of Poisson’s ratio in central orogenic belt and eastern block is inhomogeneous, suggests that the complex transformation process has been suffered in the crust. Combined with the previous research results, we speculate that there existed partial melting and mantle upwelling in the lower crust of Huailai-Yanqing basin and southern Tangshan, and lower crust detachment might have occurred on the north of Shijiazhuang, and the lower crust of Baoding-Fangshan may have been suffered mantle upwelling under the influence of extension after its detachment. The different crust structures of different areas result in the differences of crustal thickness and Poisson’s ratio distribution which are obtained by H-κ-c stacking as well as H-κ stacking.