桑木场背斜沙溪庙组节理特征与构造解析

摘要

基于对川东南桑木场背斜沙溪庙组野外出露岩石节理的观测、统计,通过运用构造解析的方法,遵循共轭节理的原则,对野外所观测到的300多条原始节理产状数据运用玫瑰花图法,进行空间几何特征的分析与描述,得到节理发育的优势产状.对此进行节理的配套与分期,得出该区共发育三套X型共轭剪节理,分别是近EW向与NNW向、近SN向与NEE向、NNE向与NWW向.最后利用赤平投影的方法分析应力场演化特征,表明该层位在沉积到发生形变至今共经历了三期构造运动:NW-SE向挤压、NE-SW向挤压、近EW向挤压.%Based on the observation and statistics of the exposed rock joints in the Shaximiao Formation of the Sangmuchang Anticline,Southeast Sichuan Basin,the joint data of more than 300 original nodes were observed and analyzed by using the method of structural analysis,following the principle of conjugate joint.In order to obtain the superiority of joint development,the author use the rose diagram of the joins to analyze and describe the geometric characteristics of space,and finally concluded that the region developed 3 sets of X-type conjugate joints by matc-hing and staging of the joints.The 3 sets of X-type conjugate joints develop with the EW and NNW,SN and NEE, NNE and NWW.Based on evolution of the tectonic stress field with the stereographic method,the results show that the target rock formation has experienced three tectonic epochs:NW-SE compression, NE-SW compression, EW compression.