显微构造中应变标志物及应变测量  

Strain Features and Strain Capacity Under Microscope

作　　者：王世锋[1] 刘瑞珣[1] 

机构地区：[1]北京大学地质学系,100871

出　　处：《高校地质学报》2002年第1期62-67,共6页Geological Journal of China Universities

基　　金：国家自然科学基金资助项目 (批准号 :49972 0 80 )

摘　　要：显微构造的运动学判别原理及方法目前已得到广泛应用 ,但其定量计算的标志还局限于石英颗粒、鲕粒、化石等球形物体及少数别的标志物。本文介绍的是书斜构造了、布丁构造、显微褶皱构造、揉皱构造和滑脱构造等 5种显微构造的应变特征及测量方法 ,这些标志的识别和测量有助于提高平衡剖面和缩短量的计算精度。在这五种情况下 ,测量应变量首先要找到视域内代表最大应变方向的变形前和变形后的长度 ,然后计算不同视域下的变形量并找出最大应变量 ,利用应变公式计算变形率。例如 :大别山构造带龟山组是一套单斜地层 ,它的显微变形很发育 ,显微褶皱显示其缩短变形量达 5 7% ,由于龟山组是单斜地层 ,其样品所代表的地层厚度内其缩短量为 5 7%。The application of microstructures in deformation analysis is well known recently. However, the marks used in stain measurement are restricted in fossils, oolites and some minerals. In this paper,the authors depicted some microstructures for strain measurement, such as domino structure, pudding structure, rumpled fold, rootless fold, etc. All these microstructures will benefit the construction of balanced cross section and the measurement of the shorten amount of a constricted area. In each of the five examples,the first thing is to direct length of fore deformation (L) along the biggest stress direction in field of vision,then calculate strains in defferent fields of vision and find out the biggest strain, and calculate the line capacity e=(L L0)/L0. For example,Guishan Group in North Huaiyang tectonic belt of Dabie mountain is monoclinic strata. The micro deformation here develops very well. The micro fold structure is one of the deformation types with a strain capacity of 0.57. It means that the strata shortening is 57%.

关 键 词：显微构造 应变标志物 应变测量 书斜构造 布丁构造 脱滑构造 显微褶皱 揉皱构造 

分 类 号：P542.1[天文地球—构造地质学]