On the universality of the vitrinite property diversity in iso-metamorphosed coals

In this topic five series of coal samples with different metamorphism degrees are selected from different areas and ages. Hie comparative researches are carried out on the main characteristics of the vitrinites concentrated by separation. It is found that dividing by the marine facies and continent facies, the vitrinite properties in the iso-metamorphosed coals belonging to the same facies but different ages still have the differences,and some differences are even more obvious.This indicates that the property diversity existed in the vitrinites in iso-metamorphosed coals has the universality, and its genesis is not limited to one factor,the coal facies.