| This paper focuses on the Barremian/Aptian boundary in the Trans-Caspian area. Results of a stratigraphical study of the uppermost Barremian and the lower Aptian succession in the Trans-Caspian area are presented. The bed-by-bed description of three sections — Keldzhe, Tekedzhik and Utuludzha — is given as well as detailed lithologic columns. Five ammonite zones are known in the studied stratigraphic interval — the Turkmeniceras turkmenicum, Deshayesites tuarkyricus, D. weissi, D. deshayesi, and Dufrenoya furcata zones. These zones are correlated with those of Europe. The Barremian/ Aptian boundary in the Trans-Caspian area should be drawn at the base of the D. tuarkyricus Zone. It corresponds to the layers with the first occurrences of Deshayesites,... |
