High-resolution radiocarbon and OSL cross-dating of Late Pleniglacial to Early Holocene aeolian succession and wildfire dynamics at the Łaskarzew site, eastern Poland

Abstract The chronology of Late Glacial and Early Holocene dune formation and wildfire activity at the Łaskarzew site, eastern Poland, was reconstructed using a combination of accelerator mass spectrometry (AMS) radiocarbon dating ( 14 C) and optically stimulated luminescence (OSL) dating. The stratigraphic profile records 13 aeolian-soil cycles, characterized by alternating phases of aeolian deposition, soil formation, and wildfire episodes, reflecting the interplay between short-term climatic oscillations and aeolian processes. Radiocarbon dates were obtained from 26 charcoal samples embedded within palaeosols and charcoal horizons and calibrated using the IntCal20 curve, while OSL dating of quartz grains provided additional chronological control for aeolian sediments. The integration of these two dating methods established a robust timeline of environmental changes. The aeolian activity began during the Oldest Dryas and intensified during the Allerød interstadial, with four distinct wildfire events associated with rapid vegetation recovery and fire-prone landscapes. The Younger Dryas was marked by widespread aeolian deposition under arid climatic conditions, with no organic layers preserved. In the Holocene, nine independent wildfire episodes spanning approximately 4500 years were identified, linked to warm climatic conditions and the dominance of pine forests. Aeolian activity persisted into the Middle Holocene, accumulating nearly three meters of sediment before stabilizing around 7 ka BP due to increased vegetation cover. This study underscores the effectiveness of integrating radiocarbon and luminescence dating to resolve Late Quaternary chronologies, providing insights into fire-vegetation dynamics and aeolian processes within the European Sand Belt.