Soil/Landform Unit 165

Landform Unit Description

Unit 165 image a
View north-west over the former Heytesbury Soldier Settlement
      Area: 11 654 ha
      0.87% of CMA region

      Rolling hills of the Heytesbury region (often referred to as the Heytesbury Soldier Settlement) are formed from Miocene marine clay, marl and limestone. Included are the catchments of Scotts Creek and Cooriemungle Creek. Faulting and slumping of the landscape has led to occasional steep scarps, but most slopes are long, gentle and straight, separated by broad drainage lines. The soils on these Miocene sediments are typically brown, grey and black texture contrast soils, with heavier textured cracking clays lower in the landscape. Soils on these sediments are significantly more fertile than the soils formed on the Neogene sediments in adjacent units (Unit 86). Free lime is often preent at depth in the soil profile. Nearly all native vegetation has been cleared as part of the soldier settlement, apart from a significant remnant stand in the centre of the Heytesbury region. Dairy farming is the main land use. Subsoils are dispersible and gully erosion has occurred along some drainage lines. Landslip and slumping is a major engineering issue that escalates when soils are waterlogged. Drainage lines and lower slopes remain waterlogged for most of the year and are prone to soil compaction (pugging) by stock.
Unit 165 geomorphology

Unit 165 image b
Gentle slopes of the highly dissected remnant plain in the Heytesbury region		Unit 165 cross section

Unit 165 graph
Unit 165 image c
Overlooking the remnant vegetation of the Heytesbury Soldier Settlement from Cowleys Creek

Component
1
2
3
4
5
Proportion of soil-landform unit
4%
65%
20%
8%
3%
CLIMATE
Rainfall (mm)

Annual: 900-1000, lowest January (40), highest August (120)
Temperature (oC)
Annual: 14, lowest July (9), highest February (18)
Seasonal growth limitations
Temperature: less than 10oC (av.) June-August
Precipitation: less than potential evapotranspiration November-March
GEOLOGY
Age and lithology

Miocene marine marl. Recent clay, sand and gravel
Geomorphology
LANDUSE
Cleared areas: Dairy
Minor uncleared areas: Nature conservation
TOPOGRAPHY
Landscape

Rolling hills
Elevation range (m)
20-170
Local relief (m)
120
Drainage pattern
Dendritic
Drainage density (km/km2)
2.6
Landform
Hills
Valley floor
Landform element
Upper slope and crest
Mid slope
Lower slope
Low rises
Alluvial flats and fans
Slope and range (%)
5 (0-12)
5 (0-10)
4 (1-7)
1 (0-3)
0 (0-1)
Slope shape
Convex
Concavo-Convex
Convex, linear
Convex
Linear
NATIVE VEGETATION
Ecological Vegetation Class

Open forest

Woodland

Woodland
Closed scrub

Closed scrub
Dominant species
E. obliqua, E. ovata, E. aromaphloia
E. ovata, E. radiata
E. obliqua, E. ovata
Melaleuca squarrosa,
Leptospermum lanigerum
Melaleuca squarrosa,
Leptospermum lanigerum
SOIL
Parent material

In situ marl

Colluvial marl

Colluvial/alluvial marl and sand

Colluvial/alluvial sand and marl

Alluvial sand and clay
Description
(Corangamite Soil Group)
Brown, grey or yellow texture contrast soils (calcardous subsoils), coarse to fine structure (20)
Mottled brown, yellow and grey texture contrast soils, coarse to fine structure (20)
Mottled yellow and grey texture contrast soils (20)
Grey sandy soil with weakly cemented pan over mottled clay (22)
Yellow grey texture contrast (31) and grey uniform clay soils (33)
Soil type sites
Surface texture
Clay loam to clay
Sandy loam to clay
Sandy loam to clay
Sandy loam
Clay loam
Permeability
Very low
Very low
Very low
Low
Very low
Depth (m)
>2
>2
>2
>2
>2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS
Heavy textured soils are very prone to pugging damage by cattle. Acidic surface.
All slopes are subject to periodic saturation are prone to severe waterlogging and pugging by cattle. Landslips and slumping of road batters are a major hazard. Soils respond well to subsurface drainage including mole drainage.
Soils are prone to severe waterlogging and pugging by cattle. Saline discharge occurs at toe slopes of landslides and in some drainage lines. Soils respond well to subsurface drainage including mole drainage.
Better draned surface soils of this element render it less prone to pugging by cattle.
Soils are prone to severe waterlogging and pugging by cattle. Soils respond well to subsurface drainage including mole drainage.
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This page contains material sourced from the Victorian Resources Online (VRO) website, originally published by the State Government of Victoria. The content is licensed under the Creative Commons Attribution 3.0 Australia licence . The material has been adapted and re-formatted; no endorsement by the Victorian Government is implied.