37. Grey and brown cracking clay soils /Ridges with sand and flats

These soils have developed on Quaternary unconsolidated material, generally of aeolian and lacustrian origin in the North West Dunefields and Plains, north and south of the Little Desert. This soil is alkaline and generally calcareous throughout.

The surface soil is usually a dark grey medium clay. This is strongly structured and self-mulching. There is a clear change to a grey (occasionally light grey), heavy clay subsoil horizon. This is strongly structured (with coarse sized peds), sodic and occasionally has very few ferromanganiferous concretions. This soil grades into a paler, light olive grey, medium heavy clay. This is strongly structured (with coarse sized peds), has slickensides and some to many calcium carbonate concretions. This soil grades into weathered regolith at depth. The profile depth is about 2 m or more with variable depth of the surface horizons, generally 5-10cm for the surface and 5 -10 cm for the subsurface, where it exists.

Notable features include:

• Cracking clay soil with self-mulching surface.
• Generally self-mulching and pedal surface condition.
• Strong consistence (strength) when dry.
• Very occasional sporadic bleached subsurface soil.
• Free (visible) calcium carbonate is common to abundant in subsoil.
• Mottling generally absent.
• There is a brown to red variant (subsoil colour).