A revised chronology and depositional history for the Outer Arumpo lunette, Willandra Lakes Region World Heritage Area, NSW

Lakes in the Willandra Lakes Region World Heritage Area exhibit distinct hydrologic histories, challenging the long-held assumption that Lake Mungo's depositional record is representative of the entire system. A new study reveals that the Outer Arumpo (OA) lunette experienced significant lake level fluctuations between ~40–38 ka ago, contrasting with the relatively stable conditions at Lake Mungo during the same period. Bayesian modeling of 52 single-grain OSL ages and sediment micromorphological analysis across seven stratigraphic units demonstrates that OA's hydrologic history is unique, with lake filling occurring from ~80–56 ka ago and subsequent rapid fluctuations. This research underscores the need for site-specific stratigraphic frameworks to accurately interpret landscape changes in multi-lake systems.

Jankowski, N., Turnbull, M., Cadd, H., Stern, N., & Willandra Lakes Region Aboriginal Advisory Group. (2025). A revised chronology and depositional history for the Outer Arumpo lunette, Willandra Lakes Region World Heritage Area, NSW. University of Wollongong. https://doi.org/10.71747/UOW-R3GK326M.30633092