Soil/Landform Unit - Surridge foothills

Footslopes that feed Six Mile and Seven Mile creeks near Concongella

Area: 5846 ha

0.25% of CMA region

Footslopes of rises, low hills and plains surround the Concongella hills east of Stawell. On the southern Wimmera CMA boundary, the slopes form part of the Dissected Western Uplands. These rises, low hills and plains of predominantly Palaeozoic metasediments and derived sediments flank the Concongella hills. This unit is also bound by colluvial deposits and alluvial systems of Six Mile and Seven Mile creeks. Upper and mid slopes of low hills are prominent, along with lower slopes, rises and drainage depressions. Drainage dissects this landscape, concentrating flow from this unit and the higher hills/steeper slopes increasing the susceptibility to gully erosion. Red texture contrast soils (generally

sodic

) are the main soil type with yellow sodic texture contrast soils (

Sodosols

) found on the lower slopes and flats (less drainage). These units are used for grazing (sheep, beef cattle), with occasional dryland cropping on the flats and lower slopes. Remnant vegetation communities recorded include Heathy Dry Forest, Grassy Dry Forest, Alluvial Terraces Herb-rich Woodland, Creekline Grassy Woodland and Grassy Woodland.

Undulating plaisn and rises with yellow box remnants
	Gully and tunnel erosion on steeper slopes

Component	1	2	3	4
Proportion of soil-landform unit	45%	30%	10%	15%
CLIMATE Rainfall (mm)	Annual: 630
CLIMATE Rainfall (mm)	Annual: 630
Temperature (^oC)	Minimum 7, Maximum 19
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Cambrian marine sandstone, siltstone and biotite schist (St Arnaud Group); Quaternary fluvial gravel, sand and silt
GEOLOGY Age and lithology
Geomorphology	2.1.2 Hills, valley slopes and plains on non-granitic Palaeozoic rock of the Dissected Western Uplands
LANDUSE	Uncleared areas: nature conservation Cleared areas: sheep and beef cattle grazing; dryland cropping
LANDUSE
TOPOGRAPHY Landscape	Undulating rises, foothills and footslopes
TOPOGRAPHY Landscape	Undulating rises, foothills and footslopes
Elevation range (m)	219–353
Local relief (m)	35–40
Drainage pattern	Dendritic
Drainage density (km/km²)	1.7
Landform	Foothills and footslopes		Undulating rises	Drainage depressions
Landform element	Moderate to gentle upper slope	Gentle lower slope	Crest	Drainage line
Slope and range (%)	7 (3-20)	4 (2-15)	3 (0-7)	2 (0-15)
Slope shape	Convex	Linear	Convex	Concave
NATIVE VEGETATION Ecological Vegetation Class	Grassy Woodland (64.1%), Alluvial Terraces Herb-rich Woodland (15.4%), Heathy Dry Forest (9.4%), Other (9.1%)
NATIVE VEGETATION Ecological Vegetation Class
SOIL Parent material	Marine sandstone, siltstone and biotite schist, intrusive granite and granodiorite	Marine sandstone, siltstone and biotite schist, intrusive granite and granodiorite	In situ marine sandstone, siltstone and biotite schist	Fluvial gravel, sand and silt
SOIL Parent material			In situ marine sandstone, siltstone and biotite schist	Fluvial gravel, sand and silt
Description (Corangamite Soil Group)	Red texture contrast soils (1) and sodic red texture contrast soils (2)	Sodic red texture contrast soils (2) and sodic yellow texture contrast soils (4)	Red texture contrast soils (1)	Sodic red texture contrast soils (2) and sodic yellow texture contrast soils (4)
Soil type sites	ALRA81, DOAGW22, LP83	ALRA81, DOAGW22, GW28	LP83, DOAGW31, LP82	ALRA81, DOAGW22, GW28
Surface texture	Sandy loam	Sandy loam	Fine sandy loam	Sandy loam
Permeability	Moderate	Moderate	Moderate to high	Slow
Depth (m)	1.2	1.5	0.7	1.5
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS Critical land features, processes, forms	Soils may be friable with better infiltration in moister areas, hardsetting and more prone to sheet and rill erosion in drier aspects. Sodic subsoil prone to gully and tunnel erosion. Susceptible to acidification in wetter areas.	Soils may be friable with better infiltration, some surfaces are hardsetting and more prone to sheet and rill erosion. Sodic subsoil prone to gully and tunnel erosion. Susceptible to acidification in wetter areas.	Friable with better infiltration in moister areas, hardsetting and more prone to sheet and rill erosion in drier areas (north and westerly aspects). Susceptible to acidification in wetter areas.	Soils may be friable with better infiltration, some surfaces are hardsetting and more prone to sheet and rill erosion. Sodic subsoil prone to gully and tunnel erosion. Susceptible to acidification in wetter areas.

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