论文部分内容阅读
地壳中各种岩类在遭受地质作用后都可以引起不同程度的改造,主要表现在组分的变化和形变。本文对北京西山一个箱状褶皱的陡翼上的灰岩变形特征作了电子显微镜研究。灰岩属中奥陶纪,其上、下均为砂岩、页岩。它们都出现发育程度不同的劈理,而以灰岩中劈理构造最为明显。光学显微镜下的特征灰岩主要由微米级(5～7μm)的方解石晶粒组成,偶可见到少量粘土矿物。方解石微粒有明显的形态定向、颗粒的压扁现象或沿方解石排列方向断续延伸(照片1)。
All kinds of rocks in the crust can cause different degrees of transformation after being subjected to geological effects, mainly in the composition of the changes and deformation. In this paper, electron microscopy has been performed on the deformation characteristics of a limestone rock on a box-shaped fold in Beijing’s Xishan Mountains. Limestone is Ordovician, its upper and lower are sandstone, shale. All of them show cleavage with different degrees of development, while cleavage structure is the most obvious in limestone. Characteristics under optical microscopy Limestone is mainly composed of calcite grains on the micron scale (5 ~ 7μm), and even few clay minerals can be seen. Calcite particles have obvious morphological orientation, particle squashed or intermittent along the direction of calcite extension (Photo 1).