The vP Velocity Structures of Sub-blocks in the North China Craton from Active Source Waveform Modeling and Tectonic Implications

作者：LIU Hanqi,TIAN Xiaofeng,LIU Baofeng,WANG Honglei

摘要：We present the 1-D crustal velocity structure of the major tectonic blocks of the North China Craton(NCC)along 36°N based on synthetic seismogram modeling of long-range wide-angle reflection/refraction data.This profile extends from southwest Yan’an of central Shaanxi Province of China(109.47°E),across the southern Trans-North China Orogen(TNCO),the southwestern part of the North China Plain(NCP),the Luxi Uplift(LU)and the Sulu Orogen(SLO),ending at Qingdao City of Shandong Province,the eastern margin of China(120.12°E)along 36°N.We utilized reflectivity synthetic seismogram modeling of the active source data to develop 1-D velocity structures of the sub-blocks of the NCC.Our final model shows that the NCC crust varies remarkably among the tectonic units with different velocity structure features.Higher lower crustal velocity and Moho depth~42 km is a major feature of the crust beneath southern Ordos Blockt.The TNCO which is composed of Lyuliangshan Mountains(LM),Shanxi Graben(SXG)and Taihangshan Mountains(TM)shows dominant trans-orogenic features.The NCP shows a dominant thickening of sediments,sharp crust thinning with Moho depth~32 km and significant lower average velocity.The SLO and the LU shows a stratified crust,higher average velocity and crust thinning with Moho depth of~35 km.Our model shows the coincidence between the deep structure and the surface geology among all the tectonic sub-blocks of the NCC.

发文机构：Geophysical Exploration Center Hebei Earthquake Agency

关键词：TheNorthChinaCRATONCrustalvelocitystructureCRATONdestructureWIDE-ANGLEreflection/refraction

分类号： P[天文地球]