The Batagay Megaslump in eastern Siberia exposes one of the oldest permafrost archives and provides insights into Beringian paleoenvironments. However, its geochronology calls for improvement given known difficulties with permafrost dating and current developments in dating techniques. Here, we present the first systematic geochronological study of the Upper Ice Complex (Yedoma) that constitutes more than half of the exposed stratigraphy based on 135 radiocarbon dates and four post infrared infrared stimulated luminescence ages. Newly obtained radiocarbon ages of bulk sediment, wood, and non-wood macrofossils from the same sediment samples span between 55,000 yrs BP and 31,000 cal yrs BP and, supplemented by radiocarbon ages of wedge ice dissolved organic carbon, bulk sediment, and macrofossils, which allow an enhanced interpretation of the dating results. Luminescence ages from the Upper Ice Complex and the units below (149 to 56 ka) provide independent age control and refine the maximum age of the Upper Ice Complex to Marine Isotope Stage 5, supported by an age of 112.8 ± 8.4 ka and rejecting several finite radiocarbon ages close to detection limit. The present study provides a robust chronology for the interpretation of paleoenvironmental proxy data from the Upper Ice Complex and enhances the overall geochronology of the Batagay Megaslump.
Opel et al. (2026) studied this question.