CONTINUOUS EARLY LAST GLACIAL PALEOENVIRONMENTAL RECORD FROM A TASMANIAN SPELEOTHEM BASED ON STABLE-ISOTOPE AND MINOR ELEMENT VARIATIONS

A columnar stalagmite from a limestone cave in the Florentine Valley, Tasmania, has been dated by three Th-230/U-234 age determinations. Con tinuous profiles of 170 delta(18)O and delta(13)C values as well as ma gnesium and strontium concentrations are presented. delta(18)O values indicate temperatures lower than today with a gradual temperature decl ine in the basal part of the profile punctuated by two short cooling e vents and culminating in a double temperature minimum between 70 and 6 0 ka. The profile shows marked similarities with the GISP ice core rec ord from Greenland which shows two short intense stadials centred on 7 4 and 70 ka preceding the Last Glacial temperature minimum. They have been correlated with 'Heinrich' events in North Atlantic marine cores which in turn have been attributed to periodic massive discharges of i cebergs into the North Atlantic. The Tasmanian speleothem record sugge sts that these events may also have affected climates in the southern hemisphere. The delta(13)C variations also appear to indicate periodic environmental change. Minor element variations were found to be signi ficantly correlated with isotopic changes. Strontium concentrations sh ow a bimodal distribution indicating control by a switching mechanism tentatively attributed to variations in calcitic dust supply to the gr ound surface above the site.