GL30
Location: Casterton
Australian Soil Classification: Melanic, Humic, Aeric PODOSOL (confidence level 3)
General Landscape Description: Level plain
Site Description: Flat, <1% slope
Land Unit: Strathdownie
Geology: Quaternary lacustrine
General Land Unit Description: This land unit comprises the Quaternary lacustrine geology south of the Glenelg River. The lacustrine deposits include lagoonal, swamp and local colluvial deposits formed in low-lying wetlands and depressions between stranded beach ridges. Parent material in this land unit comprises of sand, silt, sandy clay, peat, marl and freshwater limestone, occurring in relatively unconsolidated forms.
The soils are variable throughout this land unit due to varying depositional environments. A common soil type is a strong texture contrast soil (Chromosol, Sodosol) commonly with a bleached A2 horizon and a mottled subsoil (indicative of impeded internal drainage). The sandy topsoil can be very deep in some soils. Vertosols are also common on the plains and swales in between the dunes. Podosols occur on the flats as well as on the dunes and that may have been mapped as part of this land unit due to restrictions of scale. Many of the soils are poorly drained and exhibit signs of a perched watertable.
Key profile features:
- Sandy topsoil
- Strong texture contrast between topsoil and subsoil
- Bleached A2 horizon
- Mottled subsoil
- Sodic subsoil
- Subsoil dispersive when dry
Profile Described By: Natalie Baxter and Grant Boyle, 2nd October 2000.
