Velocity　structure　of　the　crust　and　upper　mantle　in　Xingtai　earthquake　region　and　its　adjacent　area

作     者：祝治平 张称康 盖玉杰 张建狮 聂文英 石金虎 张成科 阮红 

作者机构：1. Geophysical Prospecting Brigade State Seismological Bureau 450003 Zhengzhou China 

出 版 物：《Acta Seismologica Sinica(English Edition)》 (地震学报)

年 卷 期：1995年第8卷第3期

页      面：405-412页

核心收录：

学科分类：070801[理学-固体地球物理学] 07[理学] 0708[理学-地球物理学] 

主　　题：velocity structure lower crust upper crust upper mantle refraction 

摘      要：Two seismic refraction profiles which are perpendicular to each other, running through Xingtai earthquake region,reveal the anomalous variations of crust-mantle velocity structure and deep tectonics. Pg wave attenuatesrapidly with distance in the earthquake region. A group of strong reflections from a depth of 21. 0 km can be identified along the section from Longyao to the piedmont of Taihang Mountain, but P. waves characterized generally by strong amplitude are not obvious. Under the earthquake region and its western neighboring region, thecrustal velocity structure features high and low velocities changed alternatively. From North China plain toShanxi plateau, the velocity at the top of the upper mantle decreases progressively, while crustal thickness increases by 11 km. Moho uplifts locally in the earthquake region. The crustal fault stretching deeply to Moho andthe discontinuous sections of Moho in the earthquake region are supposed to be the channels and zones for magmatic intrusion. The uplifting of upper mantle and magmatic intrusion are responsible for the formation ofanomalous crust-mantle structures and extending basins, and for the occurrence of Xingtai earthquake as well.