北京西山北岭向斜卷入区构造应变场的初步研究

A STUDY ON TECTONIC STRAIN FIELD IN THE AREA OF THE BEILING SYNCLINE, THE WESTERN HILL, BEIJING

本文通过系统的有限应变测量,用主应变等值线及主应变方向迹线网络的形式,建立了北京西山北岭向斜卷入区的构造应变场;并通过宏观构造分析,证明这个应变场是合应变场,反映四期构动变动。在构造叠加部位,主应变迹线显示异常形态。本文还对应变场的建立方法作了讨论。

The tectonic strain field is determined from finite strain measurements in the Beiling Syn-cline area, the Western Hill, Beijing. The strain field is a resultant heterogeneous field. The direction and magnitude of the principal strain changes from place to Place. From the macroscopic gedogical evidence it is realized that the strain field was resulted from the superpostion of four tectonisms. In the principal strain contours, the direction and magnitude of anomalies may be observed where two or more generations of structures were superposed. Also, The me-thod for establishing the tectonic strain field is studied.