求翻译：层间滑动引起的煤层厚度变化煤系地层受侧向挤压后，柔性的软岩层如煤层等便产生柔性流动或层间滑动形成类似鸡窝状的煤层。其煤层变化特征一般表现为：原生结构破坏层内滑动镜面发育，煤层灰分增加。滑动构造总体位于煤层相邻的岩层内或煤层中。滑面或位于是什么意思？

The interlayer sliding seam thickness variation of coal measure strata by lateral extrusion, flexible soft rock, such as coal seams, etc., will produce a flexible flow or sliding between layers formed similar to the chicken coop like seam. The general performance of its coal seam variation is: the d