In the bottom of coal measures is an acidic intrusive body,it is directheat source of metamorphism,and provided the conversion of lignite to bituminous coal with thermodynamic power.

• 在本区煤系地层底部有一酸性侵人岩体,该侵入岩体是引起本区煤变质的直接热源,它提供了褐煤向烟煤转化的热动力。