Based on the obtained values, it can be concluded that the analysis of the racemization of amino acids is useful for determining the geological age of fossil shells of freshwater bivalve mollusks, but there are limitations regarding age. The extent of racemization is measured by the ratio of D/L isomers (it increases as a function of time and temperature and can be used for geochronology) from the same group of fossils (genera), which were preserved under similar environmental conditions, inorganic geochemistry and thermal histories. The D/L ratios were analyzed (amino acid racemization (or AAR) is the interconversion of amino acids from one chiral form (the L (laevo) amino acids which are the building blocks of proteins) to a mixture of Land D(dextro) forms. Five amino acids were used: aspartic acid (Asp), glutamic acid (Glu), leucine (Leu), phenylalanine (Phe) and isoleucine (Ile). The sampling principles of carbonate material for the analysis of amino acids from the mollusk shells and features of sample preparation are described. Racemization allows to obtain new data on the stratigraphy of Neogene-Quaternary riverine sediments and to solve the problem of their dating. The article considers the method of amino acids racemization as one of the approaches. Previously, various approaches were used for dating such rocks and for determining the stratigraphic position of fossil material found in them. The localities considered provide information on the sedimentation conditions in this region from the Pliocene to the Late Pleistocene. A review of the data in the body of literature on the geological age of the studied outcrops was undertaken. Based on the granulometric composition of the sediments and the presence in them of the fossil shells of freshwater bivalve mollusks (Bivalvia: Unionoida), an assumption has been made about the characteristics of the ancient river ecosystems of the Dniester and Prut on different Pliocene and Pleistocene time sections. A description of five outcrops of fluvial deposits located on the territory of the modern basins of the Dniester and Prut rivers is given. The article provides information on the outcrops of the Neogene-Quaternary riverine sediments of the North-Western Black Sea coastal area.

Splayer with mollusk