Comparison of Organic Matter from Upper Jurassic Oil Shale of the East European Platform and the Bazhenov Formation by Molecular and Isotopic Data

The molecular and isotopic composition of an extract from the rocks of the Bazhenov Formation in the southeast part of Western Siberia, oils that are genetically related to this formation, and products of hydrous pyrolysis of the organic matter of oil shale (Middle Volgian) of the East European Platform were studied. Common features and differences in their molecular composition were shown. The carbon isotope composition for C₁₄–C₃₀n-alkanes was determined for the first time; a negative isotope anomaly was revealed for C₂₆n-alkane in all samples studied. It was concluded that in spite of the geographical distance, specific biota was revealed in the Volga Basin. This biota conditioned an isotopic indicator, which is genetically significant.