19 Black, grey and brown sodic texture contrast soils on Neogene marl

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. However the strongly sodic soils are in a less wet area and may have developed on more recently accessed material.

Surface soils are not thick and weakly pedal overlying highly bleached, massive often deep (60+ cm) subsurface horizons which in turn abruptly overlie massive (yellow), mottled, heavy dark clays with occasional columnar structure.

Notable characteristics are the depth to the subsoil (deep upper soil), strong texture contrast and pH change between upper soil (acidic) and subsoil (alkaline) and sodic nature of the subsoil.
CLRA Soil Unit 19


Soil Sites
Site Code
Soil-landform unit
Component
ASC
FK
1:100 000 mapsheet
Upper slopeEutrophic, Mottled-Subnatric, Brown SodosolDy3.42T7621 - Colac
CrestCalcic, Mottled-Hypernatric, Grey SodosolDy3.33T7521 - Corangamite
-Melanic, Mesonatric, Blak SodosolDd1.23T7621 - Colac
FlatEutrophic, Mottled-Mesonatric, Grey SodosolDd2.42T7621 - Colac