These soils occur extensively on the basic volcanic plains, generally in the less stony areas. The organic surface soils (10–15 cm) overlie a weakly pedal to massive subsurface (A2) horizon (to 20–60 cm) with some ferruginous (or ferromanganiferous) gravel, which abruptly overlies a dark coarse structured hardsetting mottled (orange and yellow) heavy clay with some ferromanganiferous gravel, which may overlie a highly calcareous clay horizon (to 90 cm or greater) which will overlie parent material, usually with a clear boundary (>150 cm). Depth to horizon boundaries may vary due to the swelling nature of the soil, so that a subsurface horizon may not exist, with clay close to the surface, but then appear and be quite deep (and hence a greater depth to the heavy clay subsoil within metres of each other). This is called gilgai or crabhole terrain; the components are called puffs and shelves. Notable features include: texture contrast, coarse structure (columnar), very hard when dry, strong sodicity in the subsoil and possibly the surface soil, variable vertical depth and horizontal distance characteristics of surface soil, free carbonate (calcareous) at depth, deep profiles, and some ferromanganiferous gravel. |
Site Code | Soil-landform unit | Component | ASC | FK | 1:100 000 mapsheet |
Mid slope | Eutrophic, Mesonaric, Black Sodosol | Dd1.12 | T7621 - Colac | ||
CLRA52 | Upper slope | Vertic, Mesonatric, Black Sodosol | Dd2.13 | T7622 - Ballarat | |
Flat | Hypocalcic, Mottled-Hypernatric, Black Sodosol | Dd2.43 | T7621 - Colac | ||
Lower slope | Calcic, Mesonatric, Black Sodosol | Dd1.13 | T7621 - Colac | ||
Upper slope | Hypercalcic, Mottled-Hypernatric, Black Sodosol | Dd2.33 | T7621 - Colac | ||
Lower slope | Eutrophic, Mottled-Hypernatric, Black Sodosol | Dd2.43 | T7622 - Ballarat | ||
Upper slope | Eutrophic, Mottled-Mesonatric, Grey Sodosol | Dy3.33 | T7522 - Skipton | ||
MM274 | Crest | Calcic, Mottled-Hypernatric, Grey Sodosol | Dy3.33 | T7521 - Corangamite | |
MM280 | Crest | Fertic, Mottled-Hypernatric, Grey Sodosol | Dy3.43 | T7521 - Corangamite | |
Flat | Vetic (& Calcic), Hypernatric, Black Sodosol | Dd1.13 | T7721 - Geelong | ||
Flat | Vertic (& Calcic), Mottled-Mesonatric, Black Sodosol | Dd2.23 | T7621 - Colac | ||
Simple slope | Calcic, Mottled-Mesonatric, Black Sodosol | Dd2.23 | T7721 - Geelong |