Soils on Granitic Terrain

Dgh - Slopes with Duplex Soils on Devonian Granite | Dgg - Plains and Rises with Duplex Soils on Devonian Granite

Dgg - Plains and Rises with Duplex Soils on Devonian Granite

Plains and rises on granite located at and to the north of Lilydale House, Dog Rocks. These are three areas, totalling 3.3 km², or 0.5% of the Shire. The rises usually have granite outcrops and tore on the upper slopes and crest. The lower slopes are much gentler. The wash from this land system, being sandy, may influence the topsoil texture of surrounding land systems.

The main land use is grazing but there is a flora and fauna reserve at Lilydale House, Dog Rocks. This Boil has a particular susceptibility to Boneseed (Chrysanthemoides monilifera) infestations.

SOILS
The most common soil type is that of Component 1.

Mottled Brown Duplex Soils

Factual Key: Dy 3.42/sandy loam, 25-50 cm/granite 100-200 cm

Horizon	Depth (cm)	Description
A1	0-25	Dark brown (10YR 3/3) when moist; sandy loam; apedal and massive; consistence when slightly moist is firm; pH 5.5; clear boundary.
A2	25-35	Dull yellow orange (10YR 6/3) when moist; clayey coarse sand; apedal and massive; consistence when slightly moist is loose; pH 7.0; abrupt boundary.
	35-50+	Bright brown (7.5YR 5/8) when moist; with red mottles; medium clay; strong angular blocky 2 mm; consistence when moist is firm; moderate dispersibility and slaking; pH 7.5.

COMPONENT Proportion %	1 60	2 40

CLIMATE
Rainfall(av.) mm	Annual 510 – 560
Temperature(av.) °C	Annual 13
GEOLOGY
Age, rock	Devonian granite
TOPOGRAPHY
Landscape	Three isolated occurrences of undulating terrain on the south-eastern border
Elevation (range) m	30-99
Local relief (av.) m	35
Drainage pattern	Dendritic
Drainage density km/km²	1.3
Land form	Plain	Rise with tore on crest
Position on land form	Lower slope	Upper slope
Slope (range) %, slope shape	1-; Straight	3-10 ; Convex
NATIVE VEGETATION
Structure	Woodland ?
Dominant species	E. leucoxylon
SOIL
Parent material	In-situ weathered rock
Description	Mottled brown duplex soils	Shallow mottled brown duplex soils
Factual key	Db 2.22	Db 2.22
Surface texture	Sandy loam	Sandy loam
Permeability	Moderate	Moderate
Depth (range) m	1.0 - 2.0	0.3 - 1.0
LAND USE
	Grazing
SOIL DETERIORATION
Critical land features	Slope position	Slope gradient, hard setting surfaces
Processes	Surface runoff	Surface flow
Forms	Minor sheet erosion	Moderate sheet and rill erosion

Dgh - Slopes with Duplex Soils on Devonian Granite

Moderate slopes cut in the granite plains by Sutherland Creek and Moorabool River at "Darriwill", Hope's Bridge. There are only three small areas, comprising 0.1 km² in total, or 0.0296 of the Shire.

The slopes often have huge granitic outcrops and the depth of soil varies from a few centimetres to over a metre in some places. The mottled brown, duplex soils will rill and gully readily if the vegetative cover is damaged, particularly in areas which receive surface runoff from the granite plains.

SOILS
The soil occurs in patches between the rock. Where the soils are very shallow, only the A horizons may be present. The description refers to deeper profiles.

Mottled Brown Duplex Soils - Coarse Structure

Factual Keys Db 2.22/SCL, 5-20 cm/granite

Horizon	Depth (cm)	Description
A1	0-15	Dark brown (10YR 3/3) when moist, sandy clay loam; hydrophobic; apedal and massive; consistence when dry is hard; pH 6.0; abrupt boundary.
A2	15-35	Dull yellowish brown (10YR 4/3) when moist; sandy clay loam; apedal and massive; consistence when dry is hard; pH 6.0; abrupt boundary.
B	35-60+	Brown (10YR 4/6) with red mottles, clay; coarse primary structure breaking down to a find angular blocky structure 2 mm; consistence when moist is firm; clay slakes rapidly when wetted; pH 7.0.

COMPONENT Proportion %	1 100
COMPONENT Proportion %	1 100
CLIMATE
Rainfall(av.) mm	Annual 510 – 560
Temperature(av.) °C	Annual 13
GEOLOGY
Age, rock	Devonian granite
TOPOGRAPHY
Landscape	Gentle scarps at Darriwill area
Elevation (range) m	46 - 61
Local relief (av.) m	15
Drainage pattern	Dendritic
Drainage density km/km²	1.4
Land form	Scarps with tore
Position on land form	-
Slope (range) %, slope shape	10-20 ; Straight
NATIVE VEGETATION
Structure	Woodland ?
Dominant species	E. leucoxylon
SOIL
Parent material	In-situ weathered rock
Description	Mottled brown duplex soils, coarse structure
Factual key	Db 2.22
Surface texture	Sandy loam
Permeability	Moderate
Depth (range) m	0.5 - 1.2
LAND USE
	Grazing
SOIL DETERIORATION
Critical land features	Slope gradient, dispersibility
Processes	Sub-surface and overland flow
Forms	Moderate gully and sheet erosion

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