Kerogens of the Upper Jurassic Golchikha, Yanovstan, Sigov and Tochin formations in the northeastern West Siberia have been studied using modern analytical methods. Quantitative characteristics of samples (ash content, moisture), elemental composition (contents of carbon, hydrogen, sulfur, nitrogen, and oxygen), carbon isotope composition, and pyrolytic characteristics of kerogens were determined. The type and catagenesis of organic matter (OM) and generation potential of oil source rocks were estimated. It was found that the oxidizing conditions of accumulation of organic matter had a significant effect on the composition of kerogens in the northeastern West Siberia. Compositional variations of kerogens depending on the OM type and catagenesis have been revealed. The proportions of biochemical components (lipids, proteins and carbohydrates) in the initial OM in rocks and their influence on the elemental composition of kerogens have been discussed.
