摘要
北京西山北岭向斜发育同构造纤维状压力影。通过对压力影构造的分布、构造组成以及纤维束发育特征的研究,同时根据同构造压力影纤维晶体的油浸测量、计算机岩组分析、电子显微镜形态分析和递进应变分析,认为北岭向斜的压力影可分为印支期和燕山期,且均属平面应变、反向生长型。结合其他地质构造特征,从而得出北岭向斜的主体构造是形成于印支期近南北向水平挤压下的纵弯褶皱作用的结论。
Syntectonic fibrous pressure shadows are found in the Beilin syncline, the Western Hill, Beijing.Based on a study of the distribution, the material constitution and the fiber-band growth style of the fi-brous pressure shadows; and based on the immersion method measurement, computer fabric analysis,the EM shape analysis and the progressive strain analysis ot the fibrous crystals, it is considered that thepressure shadows in the Beilin syncline are of planar strain, antitaxial type; and can be divided into theIndosinian ones and the Yanshanian ones. Furthermore, in combination with the other structural fea-tures, it is suggested that the major part of the Beilin syncline was formed from flexural folding duringthe Indosinian movement marked by near-N-S-directed, horizontal compression.
关键词
压力影
构造
递进
应变历史
北京
plane strain
progressive
fibre/the Western Hill
Beijing
pressure shadows
antitaxial growth type
