Geochemical characterization of organic matter from the Middle Jurassic sediments of Western Siberia on the basis of the composition of Alkylaromatic hydrocarbons
The composition and distribution of alkyl-substituted bi- and tricyclic aromatic hydrocarbons were studied in dispersed organic matter (DOM) samples from four levels of the Middle Jurassic sequences of the southeast of Western Siberia. It was shown that differences in the distribution of alkylnaphtalenes and alkylphenanthrenes were caused by catagenetic factors, which promoted the occurrence of the secondary reactions of isomerization, alkylation, and dealkylation. The data on the composition of saturated and alkyl aromatic hydrocarbons were examined by principal component factor analysis, the results of which were used to divide the samples into natural families. The grouping of DOM samples is based on the similarity of their characteristic compositional parameters. It was shown that the families include samples from different units occurring at different depths and mostly in widely separated localities. This indicates that sediments accumulated and were transformed under similar conditions at different time periods and in different parts of the petroleum-bearing regions of the southwestern part of Western Siberia
