10 Black, brown, red and yellow sodic texture contrast soils (on lunettes and fans) on Quaternary aeolian sediments

There are limited extent of these soils depending on landform and position in the landscape. The soils are sodic texture contrast soils (Sodosols) with variable upper subsoil colour; often a perceived dominant colour amongst a mottle colour matrix. The surface soils may range from loamy sands to sandy clay loam with depths around 15–20 cm. This horizon is generally weakly pedal and may have some buckshot or gravel depending on movement of colluvial material. A subsurface horizon may or may not be present. Where present, this horizon is generally massive and more likely to contain gravel/buckshot as it sits on the heavier (clay) subsoil which generally acts as a throttle to permeability, particularly where coarse structure (e.g. columnar) has developed in conjunction with increased sodicity. The subsoils may have moderate gravel contents due to source material or an accumulation of clay and silt. The deeper clays shrink and swell producing polished surfaces (slickensides). The site drainage will have a major effect on permeability and inundation frequency. Notable characteristics are texture contrast with sodic subsoils and a coarse sand or gravel/ironstone component through the soil.

Soil Sites

Site Code	Soil-landform unit	Component	ASC	FK	1:100 000 mapsheet
CLRA5	82	Lower dune slope	Eutrophic, Mottled-Subnatric, Yellow Sodosol	Dy3.41	T7821 - Sorrento
MM229	150	Crest	Haplic, Calcic, Black Chromosol	Dy5.42	T7521 - Corangamite
MM291	151	Mid slope	Clacic, Hypernatric, Red Sodosol	Dr2.13	T7521 - Corangamite
SFS3	119	Lower slope (alluvial fan)	Vertic (& Ferric), Mottled-Subnatric, Grey Sodosol	Dy3.13	T7721 - Geelong