Materials for refining the stratigraphic chart of the Berriasian–Lower Aptian in West Siberia with regard to the clinoform subsurface structure

In light of the new clinoform model of the Neocomian, introduced at the last stratigraphic meeting, it is suggested to distinguish clinoform units instead of formations in the clinoform zone. Formations (12 in number) remain only west of the central part of the Neocomian basin (east-dipping clinoforms). In the eastern and southeastern parts of the basin, all the formations beyond the clinoform zone, which consist mostly of continental sediments, should be united into the Ust’-Taz Group.