Organic matter in Upper Devonian deposits of the Chernyshev Ridge

The study provides the first data on organic matter from Upper Devonian deposits of the Shar’yu River section (Chernyshev Ridge, Northern Urals). Oil shales from the Middle and Middle–Upper Domanik intervals and carbonaceous shales from the Upper Frasnian intervals were analyzed. The biomarker analysis revealed similar characteristics of organic matter from studied samples and Domanik-facies rocks of the Ukhta area. It was also shown that organic matter from the studied Domanik section is characterized by compositional heterogeneity. The biomarker and stable carbon isotope compositions of bitumen extracts, their fractions, and kerogen of the Middle and Middle–Upper Domanik shales are different from those of the Upper Frasnian shale, which may indicate the variation in depositional setting.