The Chenka sandstone Sequence (Lower Jurassic) of the Crimean Mountains: Stratigraphy and depositional environments

The position of the Chenka Sequence in the section, original data on its clay minerals, facies and structural parageneses with consideration of volcanic and climatic events, as well as the available published information provide grounds for accepting it as Pliensbachian-Toarcian in age. It is shown that the Chenka sandstones are a facies or group of facies deposited in deltaic-plain or delta-front environments and that it cannot be ranked as an autonomous formation or other stratigraphic unit.