Quaternary Organic Deposit from Newton Creek Valley, Western Tasmania

Abstract

Pollen and macrofossils from an organic deposit probably 44 ka BP in age record subalpine heath with abundant local Athrotaxis cupressoides. This was succeeded by subalpine heath that included Casuarina, Phyllocladus and Eucalyptus. The pollen/vegetation assemblages are comparable with present subalpine vegetation located between 850–1050 m, though the site is at 550 m and potentially below the limit of temperate rainforest (620 m). It is inferred that the vegetation altered from upper to lower subalpine heath and that the climate became warmer and wetter. The mean temperature is estimated to have been at least 3.2°C to 1.7°C colder than today. The trend of vegetation and climate change compares closely with Late Glacial changes but does not compare with changes recorded from sites of Middle Last Glacial age in the West Coast Ranges. A radiocarbon date of 34 ka BP and a trend towards warming suggests that the deposit may represent the onset of an interstadial during the Early Last Glacial Stage.