The alabandite and getchellite of hydrothermal origin, cement anatase of alkaline volcanic origin, and the high content of chlorite in coal were fist found in coals.

在西南地区晚二叠世煤中现了热液成因的硫矿和硫砷锑矿、碱性成因的胶态锐钛矿和陆源碎屑成因的斜绿泥石。