A seismic model for crustal structure in North China Craton  

作　　者：TianYu Zheng YongHong Duan WeiWei Xu YinShuang Ai 

机构地区：[1]Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences [2]Geophysical Exploration Center,China Earthquake Administration [3]Institute of Geophysics,China Earthquake Administration

出　　处：《Earth and Planetary Physics》2017年第1期26-34,共9页地球与行星物理（英文版）

基　　金：supported by the National Nature Science Foundation of China (Grant Numbers 91414301,91014006)

摘　　要：We present a digital crustal model in North China Craton(NCC). The construction of crustal model is based on digitization of original seismic sounding profiles, and new results of three-dimensional structure images of receiver functions. The crustal model includes seismic velocity and thickness of crustal layers. The depths to Moho indicate a thinning crust ~30 km in the east areas and a general westward deepening to more than 40 km in the west. The P wave velocity varies from 2.0 to 5.6 km/s in the sedimentary cover,from 5.8 to 6.4 km/s in the upper crust, and from 6.5 to 7.0 km/s in the lower crust. By analyzing regional trends in crustal structure and links to tectonic evolution illustrated by typical profiles, we conclude that:(1) The delimited area by the shallowing Moho in the eastern NCC represents the spatial range of the craton destruction. The present structure of the eastern NCC crust retains the tectonic information about craton destruction by extension and magmatism;(2) The tectonic activities of the craton destruction have modified the crustal structure of the convergence boundaries at the northern and southern margin of the NCC;(3) The Ordos terrene may represent a relatively stable tectonic feature in the NCC, but with the tectonic remnant of the continental collision during the assembly of the NCC in the north-east area and the response to the lateral expansion of the Tibetan Plateau during the Cenozoic in the south-west.We present a digital crustal model in North China Craton （NCC）. The construction of crustal model is based on digitization oforiginal seismic sounding profiles, and new results of three-dimensional structure images of receiver functions. The crustal modelincludes seismic velocity and thickness of crustal layers. The depths to Moho indicate a thinning crust ～30 km in the east areas and ageneral westward deepening to more than 40 km in the west. The P wave velocity varies from 2.0 to 5.6 km/s in the sedimentary cover,from 5.8 to 6.4 km/s in the upper crust, and from 6.5 to 7.0 km/s in the lower crust. By analyzing regional trends in crustal structure andlinks to tectonic evolution illustrated by typical profiles, we conclude that： （1） The delimited area by the shallowing Moho in the easternNCC represents the spatial range of the craton destruction. The present structure of the eastern NCC crust retains the tectonicinformation about craton destruction by extension and magmatism; （2） The tectonic activities of the craton destruction have modifiedthe crustal structure of the convergence boundaries at the northern and southern margin of the NCC; （3） The Ordos terrene mayrepresent a relatively stable tectonic feature in the NCC, but with the tectonic remnant of the continental collision during the assembly ofthe NCC in the north-east area and the response to the lateral expansion of the Tibetan Plateau during the Cenozoic in the south-west.

关 键 词：crustal velocity model MOHO sedimentary cover tectonic evolution north China Craton 

分 类 号：P315[天文地球—地震学] P542[天文地球—固体地球物理学]