|Linear dunefields with mostly narrow, sandy swales occupy most of the Little Desert, more than half of the Sunset Desert, and about half of the Big Desert. The dunes tend to be low, smooth-crested and wavy, with an overall east-west alignment.|
These dunefields overlie similar landforms to those beneath 5.2.1. An exception is to the east of Lake Wirrengren where the dunes cover several lunettes, extending some 40 km from the present lake bed. In low sites such as broad regional depressions and plains between stranded ridges the Lowan Sand may be shallow or absent, exposing fluvial or lacustrine sediments. Around the desert margins, reddish materials are common on broad flats, representing the aeolian Woorinen Formation.
Soils developed within Lowan Sand have significant profile development both on dunes and swales. Below the surface layer with humus accumulation the A horizon is an off-white sand, mostly more than 1 m thick. There is a sharp change to yellowish-red, somewhat compact clayey sand B horizons with yellow and grey mottles. Reaction in the profiles examined was neutral in the upper sands and alkaline in the B horizons. Soluble salt contents were low throughout. The physical features of the soils are those of Podosols, but this categorisation is precluded by the neutral to alkaline reaction. It seems that Podosols originally developed on Lowan Sand have been modified by accessions of calcareous dust.
Pale siliceous sand on interdune flat
in the Big Desert. Note the compact yellow
B horizon at approximately 1 m depth.
Sodosol in a locally low situation
in the Big Desert south of Murrayville.
Pale siliceous sand overlies compact
sandy clay lagoonal deposits.