THE THERMAL EVOLUTION INDICATOR OF CARBONATE ROCKS

It has been studied by the solid state C-13 NMR analysis that the chem ical composition and the structure feature of kerogen of carbonate roc ks are characteristic of different types and evolution degree. The pur pose is to show the evolution degree using the structure parameters of kerogen of carbonate rocks. The detailed analysis of the carbon aroma ticity (f(a)), the hydrogen aromaticity (H-a) and the average aromatic cluster size (X(b)) indicates that X(b) is the most effective indicat or of evolution degree, and it is not influenced by the type and evolu tion degree of kerogen. The correlation between the average aromatic c luster size and vitrinite reflectance value of kerogen has also been e stablished.