Aeolian sedimentation and climate variability during the late Quaternary in southeast Queensland, Australia

Abstract

A 25 000 yr record of aeolian sedimentation for coastal southeast Queensland, Australia is presented from Native Companion Lagoon, North Stradbroke Island. Using the easily distinguished geochemistry of the local quartz sands, we reconstruct the first terrestrial record of both local and far traveled aeolian sedimentation for the Australian region. The deposition intensity of long traveled dust sourced from mainland sites during the Last Glacial Maximum was found to be comparable to rates archived in Antarctic ice cores, which exhibit a 2 to 20 fold increase over current deposition. A mid to late Holocene arid phase is also identified indicating that climate variability during the Neoglacial had a profound impact on coastal aeolian systems in eastern Australia, as well as mainland dust sources. We attribute this to severe and prolonged drought during the Neoglacial and postulate an enhanced south-westerly airflow as a mechanism for such change. The record reflects the responsive nature of the Australian environment and its aeolian systems to climatic variability on short timescales.