Advances in Quaternary studies in Tasmania

Abstract

The last 35 years have seen rapid advances in our knowledge of climate change during the Quaternary Period in Tasmania. Extensive mapping and new dating studies, particularly since the advent of exposure dating, have revealed that maximum ice advance occurred 1 Ma ago and later advances were less extensive. Ice advances occurred several times during the last 100 ka, not only during the Last Glacial Maximum. Deglaciation was rapid after 18 ka and complete by 14 ka. Ice strongly affected limestone and produced extensive glaciokarst with deranged surface drainage. Glacial sediment plugged conduits to underground passages partially filled with glaciofluvial gravels. Periglacial erosion, and human impact since late oxygen isotope stage (OIS) 3, enhanced sediment influxes. New pollen records, particularly from Lake Selina, provide a 125 ka vegetation and climate record representative of the Southern Hemisphere. Finally, stable isotope studies of speleothem growth have revealed wide swings in climate. The climate was warm and moist during OIS 5e and early in OIS 1. Climate was cold and dry during OIS 5d and 4, and prevented speleothem growth during OIS 3 and OIS 2.