альб

Ammonite finds at the Miroshniki site, within the Albian-Cenomanian boundary interval, make it possible to identify the presence of the analogues of the Upper Albian zones Mortoniceras fallax (autochthonous burial within aleurolites) and Mortoniceras rostratum (allochthonous occurrence among phosphorite nodules). In this very section, an elasmobranchian assemblage has been isolated from the phosphorite interlayers; this is represented by 9 series and 13 genera. Small sand sharks Eostriatolamia subulata (Ag.) are dominant in its content.

The Albian-Cenomanian rocks compose a single complex of terrigenous deposits over the Volga Region. Delineation of the boundaries of the Cretaceous system units generally tends to cause difficulties, accounted for by rare finds of the fossils. In the northern part of the DonMedveditsa dislocations, natural outcrops of the Albian and the Cenomanian beds in the Burluk river valley have been examined since the 1950s. The authors have earlier made some case studies on the Gordienki, Krasny Yar, Melovatka and Moiseyevo sections.