Detailed sampling of the Lower Cretaceous beds from the wells and outcrops in the north of the Volgograd Region has revealed peculiarities in the material composition alterations along the section at the level of local stratigraphic units. Cyclicity in the Cretaceous bed formation has been established. Analyses of the authors’ own and of the earlier published paleontologic data have made it possible to date the beds relative to the general stratigraphic scale.
