Australia: The Land Where Time Began

A biography of the Australian continent 

Cooper Creek - Climate Change and Aeolian-Fluvial Interaction and Development of Source-Bordering Dunes over the Past 100 ka

In this study by the authors¹ an interpretation is provided of the interrelated aeolian and fluvial activity that occurred during the Quaternary as a result of climate change on Cooper Creek in the Lake Eyre Basin, southwestern Queensland, central Australia. Buried palaeochannels, that are now almost completely buried, are connected stratigraphically to source-bordering dunes emerging as distinctive sandy islands through the extensive muddy floodplain, which are a characteristic of it. There were pronounced periods of fluvial activity, that have been identified by luminescence dting, that represent abundant amounts of sandy alluvium from Marine Isotope Stages (MIS) 8-3. The authors¹ suggest that on Cooper Creek these sandy fluvial episodes, which were much more powerful than any such episodes occurring since, and they appear to be ranked in order of activity. Almost the entire floodplain was reworked during MIS 8-6, though the reworking was much less extensive in subsequent phases of reworking. In the late MIS 5, about 85-80 ka, and mid-MIS 3, 50-40 ka, active sandy channels provided the material for source-bordering dunes. The dunes were isolated to become emergent features after the activity of the sand channels largely ceased as they were inundated with mud after about 40 ka. According to the authors¹ the dunes have displayed remarkable endurance, as they have survived for at least 40 ka without migration, though aeolian reworking of the upper parts of some of the dunes has continued until the present. The location of source-bordering dunes was once controlled by the channels, the remnant dunes now determine the courses of many contemporary flood-channels and waterholes by deflection and confinement of overbank flows.    

Sources & Further reading

1. Maroulis, Jerry C., Gerald C. Nanson, David M. Price, and Tim Pietsch. "Aeolian–Fluvial Interaction and Climate Change: Source-Bordering Dune Development over the Past ∼100 Ka on Cooper Creek, Central Australia." Quaternary Science Reviews 26, no. 3–4 (2// 2007): 386-404.