On the chronology and development of Europe’s tallest aeolian landform: the Sarykum dune complex in the North Caspian region

The tallest aeolian landform in Europe (∼170 m above the base), the Sarykum dune complex, is located in the southwestern Caspian Depression near the Caucasus Mountains. Its morphology and evolution remain poorly studied. In this study we investigate the dune complex through a synthesis of geomorphological, geological, and geochronological methods. Our findings link its development to major regression phases of the Caspian Sea driven by climatic aridifications during the Late Pleistocene–Holocene. Optical stimulated luminescence dating indicates that dune formation began at least 60 ka during the Atelian regression, with reactivation around 11–6 ka during the Mangyshlakian regression. By the mid-Holocene, the complex had nearly reached its modern height. The Shura-Ozen’ River, which divides the dune complex in two major segments, played a significant role in the complex’s evolution, influencing aeolian sediment transport and trapping material on its banks, particularly on the left bank, where the highest Central Massif is located. Extensive vegetation now stabilizes most of the complex, except for active ridges in the Central Massif. A numerical analysis of wind potential for dune migration, based on recent meteorological data, shows that sand movement is primarily driven by self-sustaining NW–SE wind fluctuations. Paleowind analysis suggests that similar long-term wind patterns have persisted since the onset of aeolian deposition during the Atelian phase. Our study sheds new light on the Sarykum dune complex’s history and highlights its significance as a dynamic archive of climatic and geomorphic processes in the Caspian region.