Soil/Landform Unit 172

Robinson et al. (2003) Corangamite Land Resource Assessment. DPI Victoria
Gently undulating sedimentary plains of a remnant plateau located north-east of Torquay

Area:

9944 ha

0.74% of CMA region

These gently undulating plains occur as envelopes of Neogene fluvio-marine sand overlying various geologies in a number of areas across the region including Bannockburn, Torquay, Gheringhap, Maude and Lismore. These sedimentary plains of the dissected Western Plains support a wide range of vegetation classes including Plains Grassy Woodland, Plains Grassland/Plains Grassy Woodland Mosaic and Coastal Dune Scrub Mosaic. The dominant species vary from area to area along with the density and occurrence of vegetation classes

The low fertility and the low water holding capacity of the soils is an inherent limitation. Soils include an association of bleached brown, grey, yellow and/or red sandy mottled texture contrast soils or unbleached equivalents in better drained areas. Heavier surface textured soils may occur in drainage lines. These soils are prone to gully erosion which is minor to moderate in severity in some cleared areas along with sheet and rill erosion and waterlogging in wet seasons.

The gently undulating plains have been extensively cleared and now support mainly grazing
	Red highly ferruginised texture contrast soils exposed in a dam east of Torquay

Component	1	2	3	4
Proportion of soil-landform unit	60%	8%	7%	25%
CLIMATE Rainfall (mm)	Annual: 580
Temperature (^oC)	Minimum 9, Maximum 19
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Neogene fluvial sand and minor marine marl, Quaternary basalt, Devonian granite
Geomorphology	6.2.4 Plains, rises and low hills of the Sedimentary Western Plains
LANDUSE	Uncleared: Nature conservation; hardwood; gravel extraction Cleared: Sheep and beef cattle grazing; cropping (cereal); gravel extraction
TOPOGRAPHY Landscape	Gently undulating sedimentary plains
Elevation range (m)	8–253
Local relief (m)	3
Drainage pattern	Dendritic
Drainage density (km/km²)	0.8
Landform	Undulating plains
Landform element	Upper plain	Drainage line	Lower plain	Long gentle upper slopes
Slope and range (%)	3 (2–5)	1 (1–2)	3 (1–5)	1 (1–3)
Slope shape	Straight	Concave	Straight	Straight
NATIVE VEGETATION Ecological Vegetation Class	Plains Grassy Woodland (3.9%), Plains Grassland / Plains Grassy Woodland Mosaic (0.6%), Coastal Dune Scrub Mosaic (0.3%)
Dominant species	E. leucoxylon, Acacia pycnantha, E. melliodora, Casurina stricta, E. viminalis	E. camaldulensis	E. leucoxylon, Acacia spp.	E. ovata, E viminalis, E. rubida, E. obliqua
SOIL Parent material	Unconsolidated clay, silt, sand and gravel	Unconsolidated sediments and recent alluvial deposits	Unconsolidated clay, silt, sand and gravel	In situ weathered basalt
Description (Corangamite Soil Group)	Mottled brown, grey or yellow and red texture contrast soils, both fine structured (13)	Mottled brown, grey or yellow texture contrast soils, fine structure (13)	Mottled brown, grey or yellow sodic soils, coarse structure (14)	Mottled brown, yellow or grey sodic texture contrast soil, coarse structure (14, 36)
Soil type sites	MM5012, SW67, SW60	SW67, SW60, MM5012	SW93, MM5012, SW99	SW99, SW100a, CLRA47
Surface texture	Fine sandy loam	Sandy loam	Sandy loam	Clay loam
Permeability	Moderate	Moderate to low	Low	Moderate to low
Depth (m)	1.0–2.0	1.5–2.5	2	1.5
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Hardsetting surfaces and overland flow combine to create minor sheet erosion.	Seasonal high watertables, slope position and overland flow lead to periodic waterlogging and minor gully erosion.	Hardsetting surfaces and overland flow combine to create moderate gully erosion.	Hardsetting surfaces, dispersible subsoils and overland flow result in, leaching of salts, surface compaction, sheet and rill erosion and gully erosion.

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