Australia: The Land Where Time Began

A biography of the Australian continent 

Strzelecki and Tirari Deserts, Australia - Timing of Linear Dune Activity

The Australian continent has 1/3 of its land surface covered by linear dunes, though when they formed is not well understood. The study carried out by the authors¹ involved 82 samples taken from 26 sites throughout the Strzelecki and Tirari Deserts that are located in the driest part of central Australia and an OSL chronology was constructed for these dunefields. Up to 4 stratigraphic horizons are preserved in the dunes that are bounded by palaeosols, the authors¹ suggesting that it is indicated that there multiple reactivation periods were punctuated by episodic increases of environmental stability. The authors¹ found that dune activity occurred episodically at a number of times, 73-66 ka, 35-32 ka, 20-18 ka and 14-10 ka, and at other times there was partial mobilisation, during the last 75 ka, and during the Late Holocene there appears to have been an intensification of dune activity. When sediment was available for aeolian transport dune construction occurred in the Strzelecki and Tirarai Deserts, at times that coincided with cold, and conditions during marine Isotope Stage (MIS) 4, late MIS, 3 and MIS 2, and the warm, dry climates of the transition period Late Pleistocene-Holocene, and Late Holocene. During the periods that were relatively more humid in MIS 5, there were localised sediment influxes on lake floors and floodplains that were active, dune formation occurred. In southeastern Australia the timing of widespread dune activation coincided with glaciation and lower temperatures in the adjacent oceans and Antarctica.

Sources & Further reading

1. Fitzsimmons, Kathryn E., Edward J. Rhodes, John W. Magee, and Timothy T. Barrows. "The Timing of Linear Dune Activity in the Strzelecki and Tirari Deserts, Australia." Quaternary Science Reviews 26, no. 19–21 (10// 2007): 2598-616.