Helena Alexanderson

The Velika Vrbica loess-palaeosol sequence (LPS) in northeastern Serbia, located at the westernmost boundary of the Wallachian Basin, provides a high-resolution terrestrial archive of palaeoenvironmental changes spanning Marine Isotope Stages (MIS) 3 to MIS 1. This study integrates optically stimulated luminescence (OSL) dating, magnetic susceptibility (χ), and mass accumulation rates (MAR) to reconstruct climatic and environmental dynamics over the last ~41,000 years. The OSL chronology reveals consistent loess deposition from ~41 ka to 3 ka, with peak accumulation rates during MIS 3 and late MIS 2. Notably, MARs are higher during the interstadial MIS 3 compared to the Last Glacial Maximum (MIS 2), challenging conventional models that associate intensified dust deposition solely with colder glacial phases. This pattern highlights the influence of regional factors such as sediment source proximity, wind dynamics, and variations in sediment trapping efficiency. The χ record highlights fluctuations in pedogenesis and aeolian activity, which broadly correspond to climatic oscillations captured in the NGRIP δ¹⁸O ice core record. These global cold periods align with intensified dust deposition, but substantial MAR values observed during warmer interglacial phases suggest that sedimentation processes in southeastern Europe were influenced by additional, localized drivers. The Velika Vrbica LPS captures detailed environmental responses to Dansgaard-Oeschger (D-O) events, marked by rapid warming and subsequent cooling phases. These responses reflect the sensitivity of southeastern Europe to abrupt climatic shifts and reveal the nuanced relationship between global climatic drivers and regional environmental processes. Notably, the sandy layer deposited between ~32 ka and ~15 ka reflects intensified palaeowind activity during the Last Glacial Maximum, further illustrating the interplay between climate and sedimentation dynamics. Comparison with other LPSs in southeastern Europe highlights the distinct depositional patterns of Velika Vrbica, with pronounced MAR peaks during MIS 3 and considerable variability during MIS 2. These findings diverge from the widely accepted model of loess formation, emphasizing the importance of site-specific factors and regional climatic influences. For example, while most models predict lower dust input during interglacial periods, the Velika Vrbica LPS records substantial dust deposition even during MIS 3 interstadials. This challenges established paradigms and underscores the complexity of loess formation processes in dynamic semi-arid environments. By integrating high-resolution geochronological data with sedimentological and palaeoclimatic analyses, this research provides critical insights into late Quaternary climate dynamics in southeastern Europe. The Velika Vrbica LPS not only enhances our understanding of the region’s environmental history but also contributes to refining global models of loess deposition and dust dynamics. These findings emphasize the need for further site-specific investigations to disentangle the interplay between global climate systems and local environmental processes, thereby advancing our understanding of past climatic variability and its implications for future environmental changes.