16 Sands and sands with pans on Neogene sediments

These soils are found on the gently undulating plains, rises or low level plateaux in western areas of the CMA underlain by Neogene sediments (generally sands) and are in local association with texture contrast soils with very sharp boundaries between these two types, unobservable by topographical differences.

Dark organic-stained surface soils contrast with the pale conspicuously bleached sandy unconsolidated subsurface horizons which can be over 100 cm deep sitting on either an organic and/or sesquioxide pan (iron and aluminium) which has a much harder consistence. This is underlain by either a coloured subsoil (still sandy) or clay in some cases. This translocation of humic (organic) material and sesquioxides down the profile is a characteristic feature of these soils, but the boundary, though sharp, may be wavy or even tongue-like, making depth generalisations difficult. Depending on the source and amount of organic matter there may be variants where the surface (and subsurface) soils are not pale but grey or even black. These soils are strongly acidic with little retentive capacity for nutrients and highly permeable except for dense pans.

Notable characteristics are the (often deep) sandy soil with low waterholding and nutrient holding capacity and the variable depth to an organic and/or mineral pan (“coffee rock”) and heavier material below restricting water and root movement.

Soil Sites

Site Code	Soil-landform unit	Component	ASC	FK	1:100 000 mapsheet
MM328	159	Crest	?, Hymosesquic, ?, Podosol	Dy3.61	T7521 - Corangamite
MM5117	79	Flat	Melanic-Basic, ?, Bleached-Orthic Tenosol	Uc2.20	T7721 - Geelong
SW56	165	Upper slope - crest	Melacic, Humic/Sesquic, Semiaquic Podosol	Dy2.41	T7520 - Princetown
SW59	159	Upper slope - crest	Vertic, Mesotrophic, Brown Kurosol	Gn2.31	T7520 - Princetown
SW61	159	Flat	Melacic, Humic/Humosesquic, Semiaquic Podosol	Uc2.33	T7520 - Princetown
SW70	92	Upper slope	Humose, Sesquic, Semiaquic Podosol	Uc2.32	T7621 - Colac