Results of Drilling Holocene Deposits on the Spits of Yasenskii Bay (2024)

The drilling of 17 boreholes in the coastal zone of Yasenskii Bay of the Sea of Azov has yielded new data on the lithological composition and structure of the upper part of the sedimentary strata and the thickness of the layers composing it. The structure of malacological communities was analyzed, and changes were traced in the taxonomic composition of mollusks along the studied geological sections on various accumulative forms. It has been shown that the carbonate material of the beach ridges consists 90–95% of fragments or, less often, whole valves of shells of the Cerastoderma glaucum mollusk. Numerous valves of halophilic Black Sea species, including whole shells of Gastrana fragilis, were noted in the underlying sand and shell deposits of the Yasenskaya Spit and the bay bar of Khanskoye Lake. They are markers of the Ancient Azovian stage in the sea development. The surface terrain of the Kamyshevatskaya Spit was studied in detail, and three variably aged generations of beach ridges were identified.