2-D P-wave velocity structure in the mideast segment of Zhangjiakou-Bohai tectonic zone: Anxin-Xianghe-Kuancheng DSS profile  

作　　者：WANG Fu-yun(王夫运) ZHANG Xian-kang(张先康) CHEN Yong(陈颙) LI Li(李丽) CHEN Qi-fu(陈棋福) ZHAO Jin-ren(赵金仁) ZHANG Jian-shi(张建狮) LIU Bao-feng(刘宝峰) 

机构地区：[1]Geophysical Exploration Center, China Earthquake Administration, Zhengzhou 450002, China [2]Institute of Earthquake Science, China Earthquake Administration, Beijing 100036, China

出　　处：《Acta Seismologica Sinica(English Edition)》2004年第z1期32-42,共11页

基　　金：Preliminary study of State Key Basic Research Project (2001CCA02100) and National Natural Science Foundation of China (40234038).

摘　　要：In order to get the 3-D fine velocity structure in the Capital-circle area of China, 6 explosions, ranging from 1800 to 2500 kg, were conducted and recorded by an array of 240 seismographs. A reflection/refraction survey was carried out along the profile extending from Anxin county, Hebei Province northeastward to Yanshan Mountains, crossing the Zhangjiakou-Bohai tectonic zone. The 2-D velocity structure of P wave was imaging along the profile. The results show that abnormality exists in the deep structure of the Zhangjiakou-Bohai tectonic zone: The base- ment is significantly depressed, the interfaces and Moho are uplifted, and a strong velocity gradient layer is existed above the Moho that may be dislocated by deep fault. The crust of Huabei basin is thin and low velocity body ex- ists in the crust. The Yanshan Mountains′ crust is thick, the layers in the crust are quite clear and the velocity in the layer is homogeneous. Huabei basin differs from Yanshan Mountains in structure.In order to get the 3-D fine velocity structure in the Capital-circle area of China, 6 explosions, ranging from 1800 to 2500 kg, were conducted and recorded by an array of 240 seismographs. A reflection/refraction survey was carried out along the profile extending from Anxin county, Hebei Province northeastward to Yanshan Mountains, crossing the Zhangjiakou-Bohai tectonic zone. The 2-D velocity structure of P wave was imaging along the profile. The results show that abnormality exists in the deep structure of the Zhangjiakou-Bohai tectonic zone: The base- ment is significantly depressed, the interfaces and Moho are uplifted, and a strong velocity gradient layer is existed above the Moho that may be dislocated by deep fault. The crust of Huabei basin is thin and low velocity body ex- ists in the crust. The Yanshan Mountains′ crust is thick, the layers in the crust are quite clear and the velocity in the layer is homogeneous. Huabei basin differs from Yanshan Mountains in structure.

关 键 词：D P-wave velocity structure artificial explosion Capital-circle area of China Zhangjia-kou-Bohai tectonic zone crust-mantle transition zone 

分 类 号：P313.2[天文地球—固体地球物理学]