Relationships between desert dunes during the late Quaternary in the Lake Frome region, Strzelecki Desert, Australia

Abstract

Transverse and linear dunes near the ephemeral Lake Frome in the Strzelecki Desert of Australia provide evidence for a genetic geomorphic relationship between desert dune types. Transverse dunes, overlying palaeoshorelines, lie upwind from linear dunes. The sedimentology of both dune types is similar, suggesting reworking or downwind transport of the same source material over time. Clay pellets from several horizons within the linear and transverse dunes provide evidence for fluctuating water tables and high evaporation rates during those periods of aeolian activity, along with salt influx associated with the deflation of Lake Frome. We conclude that the nature and initiation of dune activity is controlled not only by aridity, but by local hydrology. OSL ages from both transverse and linear dunes indicate aeolian activity at 66-57 ka and 22-11 ka. Transverse dune building took place around 106-111 ka. Linear dune activity initiated at least 66 ka ago, with reactivation around 43-28 ka, followed by pedogenesis in response to humid conditions. Widespread dune reactivation from around 22 ka correlates broadly with the Last Glacial Maximum and late glacial period, consistent with evidence of cold, arid conditions and dune activity in Australia.