A 60 000-year record of environmental change for the Wet Tropics of north-eastern Australia based on the ODP 820 marine core

Palynomorphs from the ODP Site 820 marine core have provided a detailed record of terrestrial environmental responses to glacial–interglacial forcing over the last 250 000 years in the Australian Wet Tropics. The development of an accurate geochronological framework for this key sequence has proved challenging. Consequently, different dominant forcing mechanism(s) have been proposed to drive environmental change in the low latitudes. A new chronology for the last 60000 years, based on accelerator mass spectrometry radiocarbon (14C) dates of pollen concentrate material and the existing Marine Isotope Stage boundaries (MIS 4 to 1) has been produced. This new chronology provides a robust geochronological framework for interpreting environmental records across the region. In particular, our age model helps to resolve several debates concerning the timing of climatic changes and their impacts on both the marine and the terrestrial systems, as well as possible human arrival and associated impacts on the region’s ecosystems. Our findings suggest 14C dating of terrestrial pollen concentrate in marine sediments is a valuable tool for resolving major chronological uncertainties in potentially diagenetically altered marine CaCO3 sediments and should play a role in future multi-dating strategies