THE PB-210 CHRONOLOGY OF LATE HOLOCENE DEPOSITION IN AN EASTERN AUSTRALIAN LAKE BASIN

We report here the results of detailed (210)pb analysis of a sequence of lake sediments from Little Llangothlin Lagoon on the New England Ta blelands of New South Wales, Australia. (210)pb dating has been rarely employed in Australia and prior to this work no attempt had been made to evaluate the method using independent dating techniques. The chron ology of deposition in the lake has been modelled using the Constant I nitial Concentration (CIC) and Constant Rate of Supply (CRS) methods. Changes in the palynology and geochemistry of the sediments can be clo sely matched with well-documented historic events in the lake catchmen t. The dates of these events have been used to assess the modelled chr onologies. Within the limits of resolution of the sampling interval, t here is good agreement between the chronology modelled using the CRS a pproach and the dates inferred for geochemical and palynological event s in the sequence. The CIC method provides a less successful match wit h the historical record, although the differences between the dates de rived by the two models are small.