长江三峡地区基底层横向不均匀性  

Lateral Inhomogeneity of Basement in Three Gorges Region on the Changjiang River (Yangtze River)

作　　者：边银菊[1] 胡鸿翔[1] 高世玉[1] 

机构地区：[1]国家地震局地球物理研究所

出　　处：《中国地震》1997年第2期120-127,共8页Earthquake Research in China

基　　金：地震科学联合基金

摘　　要：对三峡地区的Ｐｇ波非纵观测资料用地震层析成象方法进行了计算处理并对解释结果作了分析。简要阐述了地震层析成象处理方法、地震走时数据的采集与分析等。基底面成象图给出了许多有意义的信息：该测区低速区的形成主要起因于岩性的差异及断层破碎带；基底面上存在３个ｖ＞６４ｋｍ／ｓ的高速度区，面积最大的一个大体呈南北走向，位于黄陵背斜西南侧，向北进入背斜区，另两个分别位于黄陵背斜东侧与测区西侧。据推测，这些高速区是由地壳内高速物质上涌造成的。Seismic tomography from Pg wave data along the non longitudinal profile in the Three Gorges Region are presented in this paper. The seismic tomography method,acquisition and analysis of seismic travel time are simply introduced. The tomography of basement reveals a lot of significant information and shows that the low velocity zone is due to the petrological variation and the faulted zone. It also demonstrates that there exists three high velocity zones with υ >6 4km/s at the basement,among which the largest one striking in north south is located at the southwest flank of Huangling anticlinorium and extends into the anticlinorium northward. The other two high velocity zones are respectively situated at the eastern flank of the anticlinorium and the western side of the profile. The high velocity zones are inferred the upwelling material with high velocity from deep crust.

关 键 词：三峡地区 地震层析成象 基底面 黄陵背斜 断裂 

分 类 号：P548.2[天文地球—构造地质学] P315.2[天文地球—地质学]