http://www.researchonline.mq.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:13332 A new map, the first based on interpretation of satellite imagery, reveals both the complexity of Australia's dunefields and their relationships with topography, climate and substrate. Of the five main sand seas, the Mallee, Strzelecki and Simpson in eastern Australia cover Quaternary sedimentary basins whereas the Great Victoria and Great Sandy dunefields in the west are formed by reworking of valley and piedmont sediments in a non-basinal landscape of low-relief ridge and valley topography. These dunefields cover large areas of the arid zone and semi-arid zone and small areas of dunes in sub-humid areas around the margins of the continent reflecting past expansion of arid climates during glacial stages of the last several glacial cycles. Several areas of low relief stand out as being largely dune-free: the limestone Nullarbor Plain, clay plains of the Georgina Basin and floodplains of rivers in the Carpentaria, Lake Eyre and Murray–Darling drainage basins where sand is rare or not transported by diminished Late Quaternary rivers. The Yilgarn Block of southwestern Australia is also surprisingly free of dunes, possibly as a result of long, deep weathering. Everywhere the history of climate change is evident in dune morphology and distribution, including large areas where the sand dune orientations are markedly divergent from modern sand moving wind directions. 2011-05-30T02:50:40.383Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:5417 Sand dunes on the Newnes Plateau (1000 m a.s.l.), west of Sydney, were active during the Last Glacial Maximum. The scattered sand dunes are forested under the modern humid, temperate climate regime. Dune types range from parabolic to transverse lee dunes and sand sheets or patches. All point to the presence of conditions marginal for aeolian activity, made possible through wind acceleration on windward slopes, ready sand supply from the weathered sandstone of the plateau and sparse vegetation cover. Modern climate envelopes of sand dune activity in Australia predict that unrealistically drier conditions are necessary to allow wind transport at this site. Only additional impediments to plant growth, such as lower temperature and lower atmospheric carbon dioxide concentrations, appear to allow the necessary conditions for dune formation. These observations and conclusions extend our understanding of the extremes of the LGM climate in humid eastern Australia, confirming that the widespread treeless vegetation was also sparse, even in areas that today have annual rainfall above 1000 mm. 2010-01-27T22:30:35.750Z ]]>