THE DIFFERENCE OF VITRINITE PROPERTIES IN ISOMETAMORPHIC COALS AND ITS GENESIS——SOME COALS FROM SOUTHWEST CHINA AS AN EXAMPLE

Based on the comparative research of vitrinite in coals of three regions in Southwest China, which have the same metamorphic series, various sedimental environment and age,it is found that they are different in the optical,chemical, technological,organo-geochemical properties and so on. Among them, the coals from Qujing district and Shuicheng and Liuzhi district,which are the same as Upper Permian coal but have different sedimental environment, have the simlarproperties,in particular,the coking propety,whereas the Mesozoic coal of Sichuan differs a lot from them. The differences raised from vari- ous age are more stronger them those raised from various sedimental environment. There are many causes that could result in the different vitrinite properties in isometamorphic coals,they are not always within the control of the geochemical property of coal-forming peat swamp or whether it affected by the sea water.