GL172

Site: GL172	Land Unit: Hillside Basalts
*Aust. Soil Class.:* Vertic, Mottled-Mesonatric, Red SODOSOL (confidence level 1) (shallow soil depth)

General Land Unit Description:
This land unit represents the gently undulating to undulating basalt plains around Ararat. The plains are often dissected with very slight rises. This site represents the lighter textured basalt soils on the slight rises, predominantly Red Sodosols. The soil indicates that there is some gilgai micro-relief although it is not that evident on the surface. Rock outcrops can occur, particularly on the crests of the small rises. Ferromanganiferous nodules can occur above the clayey subsoil. This often occurs as a thin band. The soils on the plains are commonly Brown Vertosols (GL173). There are commonly large cracks on the surface when the soil is dry and the soils themselves indicate significant movement.

Site Description:

Slope: 2.5%	Geology: Quaternary basalt
Landform pattern: Plain	Position in landscape: Mid-slope
Internal drainage: Imperfectly drained

Soil Profile Morphology

A1	0-10 cm	Dark brown (10YR3/3) fine sandy clay loam, weak subangular structure (10-20 mm), consistence weak when dry, very few medium subrounded ferruginous and manganiferous nodules (2-6 mm) pH 5.8; clear transition to:
A2	10-25 cm	Yellowish brown (10YR5/5) fine sandy clay loam, conspicuously bleached (10YR7/2) when dry, many distinct medium strong brown (10YR5/6) mottles, massive, very weak consistence when dry, medium subrounded ferruginised and manganiferous nodules are abundant (2-6 mm), pH 7.9; abrupt and wavy transition to:
	Subsoil
B21	25-45 cm	Yellowish red (5YR5/6), heavy clay, many faint medium red (2.5YR4/8) mottles, strong polyhedral (50-100 mm) parting to strong angular blocky (20-50 mm) structure, very firm consistence when dry, slickensides are evident, pH 9.0; diffuse but wavy transition to:
B22	45-55 cm	Yellowish brown (10YR5/4), heavy clay, a few fine faint mottles, strong prismatic (50-100 mm) to strong angular blocky (20-50 mm), structure, very firm consistence when dry, few distinct slickensides; transition to:
C	55+ cm	Weathered basalt
	Notes: - Dark Face
B21	Dark greyish brown, distinct soft calcareous cutans are common, pH 6.9.
B22	Dark yellowish brown

Key profile features:

Strong texture contrast
Strongly sodic top of subsoil
Alkaline at depth
Cracking subsoil
Impeded internal drainage
Bleached A2 horizon
Ferromanganiferious nodules in A2 horizon
Shallow soil
Topsoil dispersive when worked when wet
Subsoil dispersive when dry

Page top