GL18

Location: Casterton

Australian Soil Classification: Bleach-Mottled, ?, Black CHROMOSOL (confidence level 3)
General Landscape Description: Dune
Site Description: Lower slope, 2% slope
Land Unit: Sand Plains and Rises
Geology: Quaternary Aeolian

General Land Unit Description: This land unit comprises areas with reasonably deep sand deposits, mainly north of the Kanawinka fault. The vegetation commonly marks the distinct changes from a landscape comprising of deep sand to one of shallow sand. The major tree species on the deep sand is Brown Stringybark, with an understorey of heath vegetation, such as Blackboys and Tea Trees. Yellow Gums prefer the shallower sandy topsoils. The major landform in this land unit is gently undulating plains where there are gentle rises and low dunes. The common soil type on the gentle rises and low dunes is a sandy topsoil over mottled clay. The depth of sand is variable (often deeper than 50 cm) similar to this site, and can be as deep as two metres in some areas. The subsoils can be strongly acidic (Kurosol), although Chromosols and Sodosols also occur. Ferruginous nodules above the clay horizon are common. There are minor areas where dunes are the dominant landform. Podosols, Tenosols and soils with a deep sandy topsoil over a clay subsoil occur on the steeper dunes and Chromosols or Kurosols occur on the gentler dunes, with Sodosols and Vertosols on the swales and drainage depression. Podosols are soil types with a deep sandy profile that have a ‘coffee rock’ layer commonly at depth.

Surface Soil
A11	0 – 20 cm	Dark brown (10YR3/3); sand; apedal structure; very week consistence, dry; pH (field) 6.0; changes to:
A12	20 – 35 cm	Very dark grey (10YR3/1); sand; massive structure; weak consistence, dry; pH (field) 6.0; changes to:
A2	35 – 45 cm	Light grey (10YR7/2), with a few faint yellow mottles; massive structure; firm consistence, dry; pH (field) 6.0; changes to:
Subsoil
B2	45 – 75 cm	Very dark greyish brown (10YR3/2), with many distinct orange and yellow mottles; light clay, sandy; weak structure; smooth ped fabric; strong consistence, dry; pH (field) 7.0; abrupt change to:
B3	75 – 95 cm	Yellowish brown (10YR5/6); sandy clay; weak structure; pH (field) 7.0.

• Strong texture contrast between topsoil and subsoil
• Deep sandy topsoil
• Mottled subsoil
• Deeper subsoil dispersive when dry