文中指出,镜煤化作用和丝炭化作用是在煤化作用阶段,基本上同时进行的两个过程。它们区别于传统概念。随着煤化作用的进行,相应地形成煤岩组分演化的连续系列。并按它们的特征,将其分别归属为三个世代,即初始世代、中期世代和老化世代。残植煤类仅出现在初始世代和中期世代的早期阶段。 It is pointed out in the paper that the mirror-coalification and the silk-carbonization are two processes carried out basically simultaneously in the coalification stage. They are different from traditional concepts. As the coalification progresses, a continuous series of evolution of coal and rock components is formed accordingly. According to their characteristics, they are respectively assigned to three generations, namely, the initial generation, the middle generation and the aging generation. Remained coal occurs only in the early stages of the initial and middle generations.