摘要
通过徐州城区及周边山体的节理观测,阐明了研究区节理的发育特征,运用赤平投影方法分析了优势节理,获得了初始节理的产状,通过节理的配套分析得到了观测点的最大主应力,编绘了研究区的构造应力场迹线。结果表明,研究区节理走向以NE向和NW向为主,最大主应力总体上为NW-SE向,北区的最大主应力迹线向NNW向偏转,南区则逐渐向NWW向偏转,研究区初始节理系形成于印支运动,区内弧形褶皱形成早燕山运动,并伴生断层系,后期的构造运动对前期构造进行了改造,使之复杂化。
Through the joints observation of mountains in and around Xuzhou City, the development characteristics of joints in the study area were clarified. The dominant joints were analyzed by stereographic projection method, the occurrence of initial joints was obtained, the maximum principal stress of observation spots was obtained through joints matching analysis, and the trace of tectonic stress field in the study area was compiled. The results show that the joints strike in the study area is mainly NE and NW, the maximum principal stress is generally NW-SE, the trace of the maximum principal stress in the North deflects to NNW, and the South deflects to NWW gradually. The initial joints system in the study area is formed in Indosinian movement, the arc folds in the area are formed by early Yanshan movement and associated with fault system, and the later tectonic movements have transformed the previous structure and complicate it.
