THE RECORD OF CONTINENTAL DUST FROM AUSTRALIA IN TASMAN SEA SEDIMENTS

The flux of aeolian dust from Australia to Sediments of the Tasman Sea has increased during glacial stages of the last four glacial cycles. Low fluxes of dust from Australia before 350 ka were followed by an increase in stage 10 and high fluxes in peak glacial periods thereafter. The initiation of higher dust fluxes in stage 10 is consistent with previous estimates of the age of onset of aridity in the source area. Dust flux to the Tasman Sea is thought to record the intensity of deflation from the source area in interior southeastern Australia which was marked by arid conditions and possibly greater windiness during the last glacial. A transect of five cores from the central Tasman Sea revealed consistently low dust fluxes north of 33 degrees S, increasing southward to approximately 40 degrees S. Glacial to interglacial movement of the northern boundary of the dust plume, governed by the position of the subtropical ridge, was less than 6 degrees latitude, probably closer to 3 degrees (350 km). The position of the dust plume determined in this study, and its response to climate change, are significantly different from a previous reconstruction based on the measurement of quartz content of the non-biogenic sediment fraction.