Constraining the climate of the Western Caucasus from the Late Pleistocene to Holocene through isotopic analysis of speleothems

Global climate evolution since the Last Glacial Maximum is well understood but large areas of continental Eurasia are still underrepresented, masking regional disparities. While some regions have high-resolution paleoclimate records, there are significant spatial and seasonal differences in reconstructed trends, particularly with regard to Early Holocene temperature. The Western Caucasus region of the Eastern Black Sea margin, comprising modern Russia and Georgia, is of high historical and archeological significance with abundant Paleolithic sites. It served as a corridor for migration and settlement of early modern humans and Neanderthal alike, influencing the development of agriculture and major cultural achievements. Although the abundance of limestone caves within the rich karst terrain provides ample opportunity for paleoclimatic reconstruction from speleothem analysis, this approach has scarcely been utilized. Here we present novel speleothem records from three caves—Vorontsovskaya, Novoafonskaya, and Abrskil—that collectively span the last 34,000 years with minor hiatuses.

By analyzing high-resolution stable isotope data (δ¹⁸O, δ¹³C) from speleothems in these caves, we aim to evaluate the regional response to major climate events from the Late Pleistocene to the Holocene. Our approach involves high-precision Uranium-Thorium dating and micromilling for isotopic analysis corresponding to multidecadal resolution. Preliminary results indicate semi-continuous data, which will allow us to identify key perturbations and trends, such as the Younger Dryas, Heinrich, and Dansgaard-Oeschger events. These will be correlated with other regional and global data sources to provide a clearer picture of past regional climate dynamics and their connection to global climate trends. Understanding the climatic conditions and moisture sources—such as influences from the Black Sea via westerly wind systems, Mediterranean, and continental sources—may help clarify the susceptibility of regional agriculture to drought while contributing to a better understanding of global climate evolution. Additionally, identifying the link between regional climate processes and larger-scale climatic shifts can provide valuable insights for predicting future climate scenarios in the region.