New Data on the Early–Middle Pleistocene of Coastal Dagestan

The paper presents new geological, geomorphological, and stratigraphic data on the Early and Middle Pleistocene of Coastal Dagestan derived through multidisciplinaty investigations in areas of Pleistocene marine terraces and key Paleolithic sites distribution and along the western coast of the Caspian Sea. Particular attention was paid to identifying and characterizing the records of the Hirkanian transgression (MIS 5) and refining the correlations between Akchagylian and Bakunian deposits in the valley of the Rubas River. We describe the Syugyut section established on a terrace at an elevation of 60–65 m whose geomorphic position and internal structure suggest its interpretation as an accumulative complex corresponding to the maximum of the Hirkanian transgression of the Caspian Sea. In the upper course of the Rubas River, near the village of Syrtych, we examined a high terrace on the right side of the valley composed of a thick body of sand–gravel and gravel– pebble deposits underlain by horizontally bedded clays bearing a characteristic assemblage of molluscs Cerastoderma and Aktschagylia, which constrains the base of the section to the Late Akchagylian transgression, while the overlying gravel body is correlated with the terminal stage of the Bakunian. Interpretation of the Syrtych section demonstrates that Akchagylian strata occur not only at high hypsometric levels but also on lower valley areass, thereby supporting assignment of layers 4–5 at the Rubas-1 site to the Late Akchagylian. The new data provide a basis for revising the chronostratigraphy of Pleistocene deposits in coastal Dagestan.

Caspian Sea · Cerastoderma · Chronostratigraphy · Early-Middle Pleistocene · MIS 5 · Mollusca · Paleolithic sites · Pleistocene marine terraces · Sea level change · Geological formations and processes · Geology and Paleoclimatology Research · Marine and environmental studies