PAGES Australia

national science highlight

Desert dunes occupy more than one third of the Australian continent and are currently largely stable landforms thought to have formed under more widespread arid conditions during the Pleistocene. Dunes in the Strzelecki and Tirari Deserts of central Australia preserve up to four stratigraphic horizons, bounded by palaeosols, which present evidence of multiple periods of reactivation punctuated by episodes of increased environmental stability. Optically stimulated luminescence dating of the dune sediments, combined with stratigraphy, has identified discrete episodes of dune activity throughout the last full glacial cycle – around 73-66, 35-32, 22-18, 14-10 ka, with intensified activity also occurring during the late Holocene. Dune construction coincided with cold, arid conditions during Marine Isotope Stage (MIS) 4, late MIS 3 and MIS 2, and the warm, dry climates of the late Pleistocene-Holocene transition period and late Holocene. The timing of widespread dune reactivation was contemporaneous with glaciation in southeastern Australia, and cooler temperatures in the adjacent oceans and Antarctica.




Caption: Strzlecki Desert in southeastern central Australia


References:

Fitzsimmons, K.E., Rhodes, E.J., Magee, J.W. and Barrows, T.T., in press: The timing of linear dune activity in the Strzelecki and Tirari Deserts, Australia, Quaternary Science Reviews, doi: 10.1016/j.quascirev.2007.06.010

past science highlight

Only the highest elevations of the Kosciuszko Massif in southeastern Australia were glaciated during the Late Pleistocene. Exposure dating of moraines using the cosmogenic isotope Be-10 has revealed at least two glaciations. The Early Kosciuszko glaciation during Stage 4 was the most extensive, and advances during the Late Kosciszko Glaciation were progressively less extensive. The timing of the Blue Lake Advance during the Last Glacial Maximum (17-20 ka) was synchoronous between the Australian mainland and Tasmania.

Refereces:

Barrows, T. T., Stone, J. O., Fifield, L. K., and Cresswell, R. G., 2001.
Late Pleistocene glaciation of the Kosciuszko Massif, Snowy Mountains,
Australia. Quaternary Research, 55: 179-189.

Barrows, T. T., J. O., Stone, L. K., Fifield, and R. G., Cresswell, 2002.
The timing of the last glacial maximum in Australia. Quaternary Science
Reviews, 21: 159-173.