These soils occur in the south-west of the CMA where dissection of the landscape has exposed marl deposits (Gellibrand Marl). This area has a higher rainfall than the basalt plains to the north and north-east. These soils may or may not have a subsurface horizon. The surface soil (10–20 cm) is generally a dark coherent but weakly structured acidic silty clay loam, clearly or abruptly overlying a dark medium clay with yellow mottle subsoil which is sodic at depth with free carbonate. The yellow colour may predominate in some situations. The subsoil is moderately to strongly structured with a hierarchy of structure sizes. Notable characteristics include: contrast in pH between the acidic surface and the alkaline mottled sodic lower subsoil, the weakly structured surface soil which is quite heavy and has a silty feel, and slight drainage restrictions in the subsoil. |
Site Code | Soil-landform unit | Component | ASC | FK | 1:100 000 mapsheet |
Upper slope | Vertic (& Sodic) Calcic, Grey Chromosol | Dy3.13 | T7520 - Princetown | ||
Mid slope | Bleached-Vertic, Eutrophic, Yellow Chromosol | Dy3.41 | T7621 - Colac | ||
Flat | Vertic (& Sodic), Calcic, Black Chromosol | Dd1.13 | T7621 - Colac |