摘要
北京西山北岭向斜的微构造研究,特别是有限应变分析研究是一个薄弱环节。现采用统计分析计算机程序,对北岭向斜不同构造部位的砾石和碎屑颗粒进行三维有限应变分析。分析结果表明:北岭向斜的主要应变类型为平面应变,同时更多地带有压扁的成分。进一步结合递进应变分析、计算机岩组分析和北岭向斜的弹塑性有限元模拟后认为,北岭向科的“弯月型”主体构造格架,是在印支期近南北向水平挤压下以纵弯褶皱为主伴有压扁作用一次递进变形的产物。
Using authors' computer program of R_f/φ-method statistic analysis whichcan give the exacthess of R_s, R_i and θ calculated, a measurement of thethree-dimensional finite strain of many structural positions of the Beilingsyncline has been made. The results show that the major strain type ofthe Beiling syncline is planar strain and marked by much compression.Furthermore, combining the progressive strain analysis, the computerfabric analysis and the elastoplastic finite element simulation, it is consideredthat the major 'crescent' part of the Beiling syncline was formed by flexuralfolding during the Indosinian progressive deformation marked by near-N-S-striking horizontal compression.
关键词
向斜
显微构造
有限应变
北京
西山
syncline
microscopic structure analysis
Beijing
Xishan
