The change of coalbeds in thickness is caused by the slide of coal measures strata along the tendency towards northest,which is controlled by the compressive stress extending to northeast in the end of Neogene.

• 煤层厚度的这种变化，是由于新第三纪末期发生的由西南向东北方向的挤压为主的应力，使煤系地层沿倾向向北东方向滑动造成的。