These soils have developed on Recent unconsolidated material, generally of riverine origin in the North West Dunefields and Plains, in swales, flats or plains and occasional sandsheets of the Douglas Depression. Some soils may have yellow subsoils with red mottling or red/brown deep subsoil. Calcareous gradational soils (often red) also occur.
The surface soil is usually a brown sandy to sand to loamy sand. This is apedal to weakly structured. It abruptly overlies a light yellowish brown fine sand subsurface horizon, which is bleached. There is a clear change to a yellow brown (occasionally light grey) sandy clay to medium clay subsoil horizon. This is weakly (sandy) or moderately structured (coarse to medium sized peds), often with a red mottle and some quartz gravel. This soil grades into a lighter clay, sometimes with calcium carbonate segregations which then grades into weathered regolith. The profile depth is about 100 cm or more with variable depths of the surface horizons, generally 15 cm for the surface and 20 cm for the subsurface, occasionally deeper.
Notable features include:
- Texture contrast soil, seasonally wet in much of the unit, associated with a series of lakes and depressions, most of which are saline.
- Site drainage is very slow.
- Variable surface friability (generally sandy and soft, occasionally hardsetting).
- Occasional bleached subsurface soil.
- Mottled subsoil has restricted soil drainage, often strongly sodic at depth, highly dispersive and strong consistence (strength) when dry.
- Some better drained variants do occur in the unit.
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