Abstract
А new anomalous section of the Bazhenov formation was described in the territory of the Urengoy oil and gas condensate field in the northern part of Western Siberia. Article 1 presents the results of the lithological description of the core, the division of the main rocks into lithotypes, the results of granulometric and palynological analyzes. It was revealed that gray-colored sandy-clay deposits and sandy vein-like bodies are younger than the host rocks of the Bazhenov Formation, represented by black kerogen-siliceous-clay rocks. On the basis of palynological studies, as well as the similarity of the mineral and granulometric compositions of the studied sandstones with the sandstones of the Achimov strata, it was assumed that the studied clastic rocks belong to the Achimov deposits, which were intruded into the deposits of the Bazhenov Formation.