Soil/Landform Unit 145

Luenttes near Lake Martin

Area: 214 ha

0.02% of CMA region

The lunettes that occur near Derrinallum and on the north-east shore of Lake Corangamite near Lake Martin represent a few of many

lunettes

across the dissected volcanics of the Western Plains. The gently undulating lunettes represent wind blow sands and clays from swamps and lakes indicating the major prevailing wind direction over time. Lake Corangamite and the swamp of Lake Martin provide waterbodies and wetlands for a variety of flora and fauna. No remnant vegetation occurs on these lunettes which have been cleared owing to their highly fertile deep black

self-mulching

clays on the slopes and crest. Cereal production is a prominent land use along with grazing. These expansive clay soils are strongly structured with moderate site drainage. Subsoils are likely to be

calcareous

and

sodic

with depth.

Dairy farming is a land use of these lunettes

Component	1	2
Proportion of soil-landform unit	40%	60%
CLIMATE Rainfall (mm)	Annual: 590
Temperature (^oC)	Minimum 8, Maximum 19
Precipitation less than potential evapotranspiration	October-March
GEOLOGY Age and lithology	Recent clay, sand and gravel, coastal sand dunes and basalt
Geomorphology	6.1.5 Alluvium, terraces, floodplains, lakes, swamps and lunettes of the Volcanic Western Plains
LANDUSE	Uncleared: Water supply catchment; nature conservations Cleared: Sheep and cattle grazing; cropping
TOPOGRAPHY Landscape	Gently undulating lunettes
Elevation range (m)	118-170
Local relief (m)	20
Drainage pattern	Dendritic
Drainage density (km/km²)	0.9
Landform	Lunette
Landform element	Crests and upper slopes	Long gentle lower slopes
Slope and range (%)	3 (1-8)	2 (1-5)
Slope shape	Convex	Straight
NATIVE VEGETATION Ecological Vegetation Class	Absent
SOIL Parent material	Aeolian clay sit and sand	Aeolian clay silt and sand
Description (Corangamite Soil Group)	Black self-mulching clays (9)	Black self-mulching clays (9)
Soil type sites	SW87, SFS21, MM114	SW87, SFS21, MM114
Surface texture	Light clay	Light clay
Permeability	High	High to moderate
Depth (m)	>2	>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS	Uniform expansive clay. Firable, self-mulching upper soil. Sticky when wet. Strong fine structure. Alkaline, sodic and calcareous at depth. Moderate rapid site drainage.	Uniform expansive clay. Friable, self-mulching upper soil. Stocky when wet. Strong fine structure. Alkaline, sodic and calcareous at depth. Moderate site drainage.

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