Abstract
Little is known about the Pleistocene climatic context of northern Australia at the time of early human settlement. Here we generate a palaeoprecipitation proxy using stable carbon isotope analysis of modern and archaeological pandanus nutshell from Madjedbebe, Australia’s oldest known archaeological site. We document fluctuations in precipitation over the last 65,000 years and identify periods of lower precipitation during the penultimate and last glacial stages, Marine Isotope Stages 4 and 2. However, the lowest effective annual precipitation is recorded at the present time. Periods of lower precipitation, including the earliest phase of occupation, correspond with peaks in exotic stone raw materials and artefact discard at the site. This pattern is interpreted as suggesting increased group mobility and intensified use of the region during drier periods.
Abstract
In contrast to the detection and resolution of Late Pleistocene interstadials (Marine Isotope Stages; MIS 5c, 5a and 3) in marine and ice core-based oxygen isotope records, accurately defining palaeosea-levels for these events from sea level indicators remains a challenge. Commonly, such investigations have been undertaken in tectonically active, subduction-related settings, on emergent marginal marine-coastal successions above present sea level, given that the higher ice volumes during these Marine Isotope Stages resulted in ice-equivalent sea levels significantly below present, particularly in far-field settings. Delineation of palaeosea-levels for this period, has accordingly involved an assumption about the long-term rate of coastal uplift. Core SV#23 collected from the tectonically highly stable, remote far-field setting of southern Gulf St Vincent, southern Australia, in a present water depth of 40 m obtained a 3.89 m undisturbed sedimentary record of Late Pleistocene
Speleothem record of mild and wet mid-Pleistocene climate in northeast Greenland sciencemag.org - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from sciencemag.org Daily Mail and Mail on Sunday newspapers.