41. Shallow and sandy soils, sodic brown texture contrast soils/Hills and low hills

These soils have developed on Palaeozoic sediments, generally of Grampians sandstone making up Mount Arapiles, outlying in the North West Dunefields and Plains, south of the Little Desert. Soils are either Rudosols, sandy soils such as Tenosols or heavier soils such as Sodosols on the footslopes. The soils are acidic in higher positions but may be alkaline in lower positions (accumulation zones).

The surface soil is usually a dark greyish brown loamy sand which is apedal to weakly structured. This sharply overlies a yellowish brown sandy clay loam with an occasional bleached subsurface horizon in between. There is a clear change to a brown sandy clay loam to sandy clay upper subsoil horison. This is mottled, weakly structured (coarse to medium sized peds) with some quartz or rock fragments. This soil grades into lighter textured weathered material (sandstone). The profile depth is about 60 cm, less or more depending on topographic position with variable depths of the surface horizons, generally 5 cm for the surface, occasionally more.

Notable features include:

• Gradational and texture contrast soils.
• Variable surface condition (generally soft, occasionally hardsetting) with sandy surfaces.
• Occasional sporadic or conspicuously bleached subsurface soil.
• Strong consistence (strength) of heavier subsoil when dry.
• Texture contrast may not be spatially consistent depending on topographic position and rock formation.
• The heavier soils may be mottled, indicating restricted drainage and often sodic.