Timing and formation of coastal dunes in Northern and Eastern Australia

Abstract

This article revisits the debate about the processes of coastal dune initiation in Australia. A review of the dates published so far on coastal dunes in Australia indicates that these belong to identifiable process regions. Those to the north and northeast seem to be largely derived from the deflation, at low sea levels, of exposed deltaic sediments, which are subsequently reworked by episodes of active transgressive dune development. In the southeast, the dunes, like other coastal depositional features, are largely derived from the alongshore sediment transport system, which is active along this coast at times of higher sea level. Apart from during glacial maxima, episodes of dune transgression, where a source is identifiable, seem to be initiated along the shoreline, strongly suggesting that marine disturbance is the trigger. Although, in many cases, these are also at times when climate is favourable to active transgressive dune development, the eastern Cape York dune fields make it clear that this is not a necessary condition. Show more