Structure and Depositional Environments of the Cenomanian–Coniacian Sequence in Crimea

This paper presents the results of a facies analysis of the Upper Cretaceous deposits in Southwestern and Central Crimea and a characterization of the Cenomanian–Coniacian sequence. This geological body, bounded by surfaces of parallel unconformities, comprises beds of six lithological types, each formed in a specific ramp setting. Their migration due to transgressive-regressive sea-level fluctuations resulted in the formation of seven parasequences. The spatio-temporal changes within these parasequences allowed for the identification of a Cenomanian transgressive systems tract and a Turonian–Coniacian highstand systems tract. The reconstruction of the paleogeographic evolution during their formation showed that for most of the time, the seafloor in the Crimean segment of the Late Cretaceous epicontinental sea was located above the storm wave base. The conducted research provides additional justification and refinement for correlation frameworks. The results can be used to improve the regional stratigraphic scheme of the Upper Cretaceous of Crimea.