Ssa | Ssb | Ssc | Ssd | Sse | Ssf | Ssg | Ssh | Ssi
4.6 Silurian sedimentary map units (Ss)
The Silurian sedimentary landscape is limited to narrow bands south of Upper Beaconsfield, Pakenham Upper, and a strip running from Cockatoo North to Nangana. The sedimentary terrain ranges from steep rocky crests and highly dissected steep slopes near the metamorphic aureole, to low undulating hills and broader drainage depressions. Slopes range from 21-35 per cent, with an average gradient of 25 per cent in the steeper hill country, while in the low undulating hills, slopes range from 10-25 per cent, with an average gradient of 16 per cent.
Large areas of sedimentary material have been overlaid by volcanic material or have undergone metamorphism during igneous intrusions.
Grazing has taken place since early European settlement. Loss of vegetation cover through clearing, combined with periods of high grazing have modified the soils present. In many cases, erosion has removed much or all of the original topsoil, while cultivation has resulted in mixing of topsoil and subsoil. Many soil types present are considered to be modified soils and are likely to differ from undisturbed soils in their natural state.
Soils vary considerably due to marked changes in land use, topography and climate. Soil depth varies markedly, steep crests and slopes have shallow to very shallow soils while gentle crests have increased soil depth. The steep slopes are subject to significant erosion. Lower slopes are subject to a build up of colluvial material leading to the development of deeper soils. Flat areas and drainage depressions also have deep soils formed through alluvial deposition. In general, shallow stony brown Chromosol soils are common where rocky crests and steep rocky slopes occur. Weak, stony yellow Dermosol and Chromosol soils predominate where soil depth increases, especially when moderate slopes are encountered. Occasionally brown Chromosol and Dermosol soils occur in areas of good drainage. Surface stone is common on all crests and steep to moderate slopes.
Soils of the low undulating hills show less variation and soil depth regularly exceeds two metres in drainage lines. Soils present on gentle crests are mostly brown Chromosols . Where shallow rock outcrops, brown Dermosols may be present. Bleached, mottled brown Dermosol soils also dominate the very gentle slopes and broad drainage depressions. The presence of significant surface stone is restricted to isolated rocky crests and steep slopes.
Soils with bleached A2 horizons have high percentages of silt and fine sand. The A horizons therefore have low liquid limits, and when saturated these soils become sloppy and have little cohesive strength. If this horizon is exposed by the removal of vegetation and topsoil the A2 horizons are easily eroded.
On many of these units, excluding the flats and drainage depressions, a layer of stones exist in the A2 horizon and the top of the B1 horizon. These sedimentary stones appear as discreet layers, are generally angular in shape and range in size from 2-60 cm in diameter. Stone may comprise up to 80 per cent of the volume of the A2 horizon. Stones in the B2 horizon are well distributed, although there may be an accumulation of stones on top of the C horizon.
Various land degradation problems exist within this sedimentary landscape. In the steeper terrain, sheet and gully erosion occur where vegetation cover is sparse. The presence of highly fractured rock outcrop and shallow stony soils contributes to local and regional groundwater recharge. The sodic subsoils present in the low, undulating terrain have also contributed to significant gully erosion. Waterlogging is common along drainage lines and below leaking dams. In these situations, spiny rush is a good indicator of waterlogging and possible salinity.
Land management considerations
The steep sedimentary terrain, especially nearer the metamorphic aureole, has obvious hazards for all rural residential land uses. The major limitations are steep slopes, depth to hard rock and shallow soil depth. The steep terrain is highly susceptible to sheet and gully erosion, especially where vegetation cover is poor.
The siting of access tracks, building foundations, septic tanks and dams is made extremely difficult by steep slopes, depth to rock and shallow soils. Soil conservation measures will be required to minimise erosion during site construction.
The low undulating hills are more suited to a range of land uses. The major concerns include subsoil permeability and dispersibility. Shallow depth to hard rock may be a problem on crests.
With rural residential development rapidly increasing in these areas, careful design of effluent disposal fields, farm dams and secondary roading is required. Consideration must also be given to dam construction and the impact upon environmental streamflows.
Soil conditions do not favour intensive agriculture on these map units. Limitations on grazing are less severe and can be overcome with appropriate stocking rates and improved land management.
Plate 17 - Map Units" Ssa, Sse, Ssb - Brown Chromosol | Plate 18 - Map Units: Ssc, Ssd, Ssf - Yellow Dermosol |
Plate 19 - Map nits: Ssh, Ssi, Ssg - Brown Chromosol |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.5 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Nil | |
Landform Pattern: | Rolling hills | Drainage: | Well drained | |
Landform Element: | Crest | Rock Outcrop: | < 20% | |
Slope a) common: | 7% | Depth to Hard Rock: | 0.5-1.3 m (variable) | |
Slope b) range: | 3-15% | |||
Potential Recharge to Groundwater: | High | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | Low | Low | Very low | Very low | Low | Low |
Incidence | Low | Low | Very low | Low | Low | NA |
Site S35 | ||
A1 | 0-15 cm | Greyish brown (10YR5/2) silty loam, strong subangular blocky structure, peds 5-10 mm, rough fabric, firm consistence, a few medium (6-20 mm) subangular sedimentary pebbles, pH 6.0. Clear transition to: |
A2 | 15-30 cm | Reddish yellow (7.5YR6/6) silty clay loam, moderate polyhedral structure, peds 20-50 mm rough fabric, weak consistence, many large subrounded sedimentary pebbles, pH 6.2. Gradual transition to: |
B2 | 30-90 cm | Strong brown (7.5YR5/6) light medium clay, many coarse distinct yellowish red mottles, strong subangular blocky structure, peds 5-10 mm, smooth fabric, very firm consistence, large (20-60 mm) subrounded sedimentary pebbles are common, pH 5.9. Gradual transition to: |
C | 90+ cm | Weathered sedimentary rock. |
Factual Key: | Gn3.84 (major), Dy3.41 (minor) |
Australian Soil Classification: | Mottled, Magnesic, Brown DERMOSOL; thick, gravelly, silty/clayey, moderate (confidence level 2) |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 5.5 | 17 | VL | M | S | S | S | H | VL |
A2 | 5.5 | 20 | VL | L | D | S | S | L | L |
B2 | 5.5 | 12 | VL | M | D | S | S | VL | L |
Permeability: | Moderate (average 130 mm/day, range 15-260 mm/day) |
Available Water Capacity: | Moderate (135 mm H2O) |
Linear Shrinkage (B horizon): | Low (12%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T2S3-4 | Depth to hardrock (variable) |
Effluent Disposal (septic tanks) | 3-4 | Depth to impermeable layer (variable) |
Farm Dams | 4-5 | Depth to hardrock (variable) |
Building Foundations slab stumps/footings | 3 3-2 | Slope Depth to hardrock (variable) |
Secondary Roads | 3 | Slope, proportion of stones and boulders, USG |
Rural Residential Development | 4-5 | Farm dams |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.3 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Nil | |
Landform Pattern: | Rolling hills | Drainage: | Well drained | |
Landform Element: | Hillslope | Rock Outcrop: | < 30% | |
Slope a) common: | 35% | Depth to Hard Rock: | 0.5-1.3 m | |
Slope b) range: | > 33% | |||
Potential Recharge to Groundwater: | High | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | High | Moderate | Very low | High | Low | Low |
Incidence | High | Moderate | Low | Low | Low | NA |
Site S35 | ||
A1 | 0-10 cm | Greyish brown (10YR5/2) silty loam, strong subangular blocky structure, peds 5-10 mm, rough fabric, firm consistence, few medium (6-20 mm) subangular sedimentary pebbles, pH 6.0. Clear transition to: |
A2 | 10-30 cm | Reddish yellow (7.5YR6/6) silty clay loam, moderate polyhedral structure, peds 20-50 mm, rough fabric, weak consistence, many large subrounded sedimentary pebbles, pH 6.2. Gradual transition to: |
B2 | 30-85 cm | Strong brown (7.5YR5/6) light medium clay, many coarse distinct yellowish red mottles, strong subangular blocky structure, peds 5-10 mm, smooth fabric, very firm consistence, large (20-60 mm) subrounded sedimentary pebbles are common, pH 5.9. Gradual transition to: |
C | 85+ cm | Weathered sedimentary rock. |
Factual Key: | Gn3.84 (major), Dy3.41 (minor) |
Australian Soil Classification: | Mottled, Magnesic, Brown DERMOSOL; thick, gravelly, silty/clayey, moderate (confidence level 2) |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 5.5 | 17 | VL | M | S | S | S | H | VL |
A2 | 5.5 | 20 | VL | L | D | S | S | L | L |
B2 | 5.5 | 12 | VL | M | D | S | S | VL | L |
Permeability: | Moderate (average 130 mm/day, range 15-260 mm/day) |
Available Water Capacity: | Moderate (130 mm H2O) |
Linear Shrinkage (B horizon): | Low (12%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T5S4 | Steep slope |
Effluent Disposal (septic tanks) | 5 | Steep slope |
Farm Dams | 5 | Steep slope |
Building Foundations slab stumps/footings | 5 4 | Steep slope Steep slope, susceptibility to slope failure |
Secondary Roads | 5 | Steep slope |
Rural Residential Development | 5 | Secondary roads, farm dams, effluent disposal, building foundations (slab) |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.5 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Nil | |
Landform Pattern: | Rolling hills | Drainage: | Well drained | |
Landform Element: | Hillslope | Rock Outcrop: | 20% | |
Slope a) common: | 25% | Depth to Hard Rock: | 0.5-1.3 m (variable) | |
Slope b) range: | 21-32% | |||
Potential Recharge to Groundwater: | Moderate | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | Moderate | Low | Moderate | Moderate | Low | Low |
Incidence | Moderate | Moderate | Low | Low | Low | NA |
Site S34 | ||
A1 | 0-10 cm | Brown (10YR5/2) silty loam, moderate polyhedral structure, peds 10-20 mm, rough fabric, firm consistence, pH 5.5. Abrupt transition to: |
A2 | 10-40 cm | Brown (7.5YR5/4) light clay, bleached (10YR8/2) when dry, a few coarse faint brownish yellow mottles, moderate polyhedral structure, rough fabric, peds 10-20 mm, firm consistence, a few large subrounded sedimentary pebbles, pH 5.7. Gradual transition to: |
B21 | 40-70 cm | Brownish yellow (10YR6/6) heavy clay, coarse prominent yellowish red mottles are common, moderate polyhedral structure, peds 2-5 mm, rough fabric, firm consistence, a few large subrounded sedimentary pebbles, pH 5.8. Gradual transition to: |
B22 | 70-110 cm | Light yellowish brown (10YR6/4) heavy clay, many very coarse prominent yellowish red mottles and very coarse distinct pale brown mottles, moderate polyhedral structure, peds 2-5 mm, rough fabric, firm consistence, a few large subrounded sedimentary pebbles, pH 6.2. Gradual transition to: |
C | 110+ cm | Weathering sedimentary rock. |
Factual Key: | Gn4.64 (major), Dy3.41 (minor) |
Australian Soil Classification: | Bleached-Sodic, Magnesic, Yellow DERMOSOL; thick, slightly gravelly, silty/clayey, deep (confidence level 2) |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 4.6 | 8 | VL | L | D | D | T | H | VL |
A2 | 4.6 | 18 | VL | VL | D | D | S | VL | VL |
B21 | 4.7 | 7 | VL | M | D | D | S | VL | VL |
B22 | 5.4 | 5 | VL | M | D | D | S | VL | L |
Permeability: | Moderate (average 155 mm/day, range 90-300 mm/day) |
Available Water Capacity: | Moderate (150 mm H2O) |
Linear Shrinkage (B horizon): | Moderate (16.5%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T4S3-4 | Slope |
Effluent Disposal (septic tanks) | 4 | Slope |
Farm Dams | 5 | Slope |
Building Foundations slab stumps/footings | 4 3 | Slope Slope, susceptibility to slope failure, linear shrinkage |
Secondary Roads | 4 | Slope |
Rural Residential Development | 5 | Farm dams |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.3 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Nil | |
Landform Pattern: | Rolling hills | Drainage: | Well drained | |
Landform Element: | Hillslope | Rock Outcrop: | < 10% | |
Slope a) common: | 16% | Depth to Hard Rock: | 0.8-1.5 m | |
Slope b) range: | 11-20% | |||
Potential Recharge to Groundwater: | Moderate | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | Moderate | Low | Moderate | Moderate | Low | Low |
Incidence | Moderate | Moderate | Low | Low | Low | NA |
Site S34 | ||
A1 | 0-10 cm | Brown (10YR5/2) silty loam, moderate polyhedral structure, peds 10-20 mm, rough fabric, firm consistence, pH 5.5. Abrupt transition to: |
A2 | 10-40 cm | Brown (7.5YR5/4) light clay, bleached (10YR8/2) when dry, a few coarse faint brownish yellow mottles, moderate polyhedral structure, rough fabric, peds 10-20 mm, firm consistence, a few large subrounded sedimentary pebbles, pH 5.7. Gradual transition to: |
B21 | 40-70 cm | Brownish yellow (10YR6/6) heavy clay, coarse prominent yellowish red mottles are common, moderate polyhedral structure, peds 2-5 mm, rough fabric, firm consistence, a few large subrounded sedimentary pebbles, pH 5.8. Gradual transition to: |
B22 | 70-115 cm | Light yellowish brown (10YR6/4) heavy clay, many very coarse prominent yellowish red mottles and many very coarse distinct pale brown mottles, moderate polyhedral structure, peds 2-5 mm, rough fabric, firm consistence, a few large subrounded sedimentary pebbles, pH 6.2. Gradual transition to: |
C | 115 cm | Weathered sedimentary rock. |
Factual Key: | Gn4.64 (major), Dy3.41 (minor) |
Australian Soil Classification: | Bleached-Sodic, Magnesic, Yellow DERMOSOL; thick, slightly gravelly, silty/clayey, deep (confidence level 2) |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 4.6 | 8 | VL | L | D | D | T | H | VL |
A2 | 4.6 | 18 | VL | VL | D | D | S | VL | VL |
B1 | 4.7 | 7 | VL | M | D | D | S | VL | VL |
B2 | 5.4 | 5 | VL | M | D | D | S | VL | L |
Permeability: | Moderate (average 155 mm/day, range 90-300 mm/day) |
Available Water Capacity: | Moderate - High (150 mm H2O) |
Linear Shrinkage (B horizon): | Moderate (16.5%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T3S3 | Slope, topsoil condition (A2), available water capacity, susceptibility to sheet erosion, susceptibility to sheet and wind erosion |
Effluent Disposal (septic tanks) | 3-4 | Depth to impermeable layer (variable) |
Farm Dams | 4-5 | Depth to hardrock (variable) |
Building Foundations slab stumps/footings | 4 3 | Slope Slope, susceptibility to slope failure, linear shrinkage |
Secondary Roads | 4 | Slope |
Rural Residential Development | 4-5 | Secondary roads, farm dams, building foundations (slab) |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.5 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Nil | |
Landform Pattern: | Low hills | Drainage: | Well drained | |
Landform Element: | Crest | Rock Outcrop: | 0-20% | |
Slope a) common: | 4% | Depth to Hard Rock: | 0.75-1.3 m (variable) | |
Slope b) range: | 2-7% | |||
Potential Recharge to Groundwater: | High | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | Low | Low | Very low | Very low | Low | Low |
Incidence | Low | Low | Very low | Very low | Low | NA |
Site S35 | ||
A1 | 0-15 cm | Greyish brown (10YR5/2) silty loam, strong subangular blocky structure, peds 5-10 mm, rough fabric, firm consistence, a few medium (6-20 mm) subangular sedimentary pebbles, pH 6.0. Clear transition to: |
A2 | 15-30 cm | Reddish yellow (7.5YR6/6) silty clay loam, moderate polyhedral structure, peds 20-50 mm, rough fabric, weak consistence, many large subrounded sedimentary pebbles, pH 6.2. Gradual transition to: |
B2 | 30-90 cm | Strong brown (7.5YR5/6) light medium clay, many coarse distinct yellowish red mottles, strong subangular blocky structure, peds 5-10 mm, smooth fabric, very firm consistence, large (20-60 mm) subrounded sedimentary pebbles are common, pH 5.9. Gradual transition to: |
C | 90+ cm | Weathered sedimentary rock. |
Factual Key: | Gn3.74 (major) Dy3.41 (minor) |
Australian Soil Classification: | Mottled, Magnesic Brown DERMOSOL; thick, gravelly, silty/clayey, moderate (confidence level 2) |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 5.5 | 17 | VL | M | S | S | S | H | VL |
A2 | 5.5 | 20 | VL | L | D | S | S | L | L |
B2 | 5.5 | 12 | VL | M | D | S | S | VL | L |
Permeability: | Moderate (average 130 mm/day, range 15-260 mm/day) |
Available Water Capacity: | Moderate (115 mm H2O) |
Linear Shrinkage (B horizon): | Low (12%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T2S3 | Available water capacity, gravel/stone/boulder content |
Effluent Disposal (septic tanks) | 3 | Depth to impermeable layer |
Farm Dams | 4 | Depth to hardrock, permeability, dispersibility of subsoil |
Building Foundations slab stumps/footings | 2 2 | Nil Nil |
Secondary Roads | 3 | Proportion of stones and boulders, USG |
Rural Residential Development | 4 | Farm dams |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.5 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Very low | |
Landform Pattern: | Low hills | Drainage: | Imperfectly drained | |
Landform Element: | Hillslope | Rock Outcrop: | < 5% | |
Slope a) common: | 7% | Depth to Hard Rock: | > 1.5 m | |
Slope b) range: | 4-10% | |||
Potential Recharge to Groundwater: | Low | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | Low | Low | Low | Very low | Low | Low |
Incidence | Low | Low | Low | Very low | Low | NA |
Site S34 | ||
A1 | 0-10 cm | Brown (10YR5/2) silty loam, moderate polyhedral structure, peds 10-20 mm, rough fabric, firm consistence, pH 5.5. Abrupt transition to: |
A2 | 10-40 cm | Brown (7.5YR5/4) light clay, bleached (10YR8/2) when dry, a few coarse faint brownish yellow mottles, moderate polyhedral structure, rough fabric, peds 10-20 mm, firm consistence, a few large subrounded sedimentary pebbles, pH 5.7. Gradual transition to: |
B1 | 40-75 cm | Yellowish brown (10YR6/6) heavy clay, coarse prominent yellowish red mottles are common, moderate polyhedral structure, peds 2-5 mm, rough fabric, firm consistence, a few large subrounded sedimentary pebbles, pH 5.8. Gradual transition to: |
B2 | 75-115 cm | Light yellowish brown (10YR6/4) heavy clay, many very coarse prominent yellowish red mottles and many very coarse distinct pale brown mottles, moderate polyhedral structure, peds 2-5 mm, rough fabric, firm consistence, a few large subrounded sedimentary pebbles, pH 6.2. Gradual transition to: |
C | 115+ cm | Weathered sedimentary rock. |
Factual Key: | Gn4.64 (major) Dy3.41(minor) |
Australian Soil Classification: | Bleached-Sodic, Magnesic, Yellow DERMOSOL; thick, slightly gravelly, silty/clayey, deep |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 4.6 | 8 | VL | L | D | D | T | H | VL |
A2 | 4.6 | 18 | VL | VL | D | D | S | VL | VL |
B1 | 4.7 | 7 | VL | M | D | D | S | VL | VL |
B2 | 5.4 | 5 | VL | M | D | D | S | VL | L |
Permeability: | Moderate (average 155 mm/day, range 90-300 mm/day) |
Available Water Capacity: | Moderate (150 mm H2O) |
Linear Shrinkage (B horizon): | Moderate (16.5%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T2S3 | Condition of topsoil (A2), available water capacity |
Effluent Disposal (septic tanks) | 4 | Drainage |
Farm Dams | 4 | Permeability |
Building Foundations slab stumps/footings | 4 4 | Drainage Drainage |
Secondary Roads | 4 | Drainage |
Rural Residential Development | 4 | Secondary roads, farm dams, effluent disposal, building foundations |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.5 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Low | |
Landform Pattern: | Low hills | Drainage: | Imperfectly drained | |
Landform Element: | Hillslope | Rock Outcrop: | < 5% | |
Slope a) common: | 2% | Depth to Hard Rock: | > 1.5 m | |
Slope b) range: | 1-3% | |||
Potential Recharge to Groundwater: | Low | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | Low | Low | Low | Very low | Low | Low |
Incidence | Low | Low | Low | Very low | Low | NA |
SITE S38 | ||
A1 | 0-10 cm | Dark greyish brown (10YR4/2) silty loam, moderate structure, peds 5-10 mm, rough fabric, weak consistence, pH 6.1. Abrupt transition to: |
A2 | 10-40 cm | Very pale brown (10YR7/3) sandy clay loam fine sandy, bleached (10YR8/2) when dry, coarse faint very pale brown mottles are common, weak subangular blocky structure, peds 10-20 mm, rough fabric, firm consistence, very few large subrounded and rounded sedimentary pebbles, pH 6.1. Clear transition to: |
B21 | 40-80 cm | Light yellowish brown (7.5YR5/6) medium clay, many medium faint red and orange mottles, strong polyhedral structure, peds 2-5 mm, smooth fabric, firm consistence, subrounded sedimentary stones are common, pH 5.9. Gradual transition to: |
B22 | 80-110 cm | Yellowish brown (10YR5/4) medium clay, many coarse prominent red mottles and medium faint orange mottles, strong polyhedral structure, peds 20-50 mm, breaking down to 2-5 mm, smooth fabric, firm consistence, pH 6.1. Gradual transition to: |
C | 110-145+ cm | Weathered sedimentary rock. |
Factual Key: | Dy3.41 (major), Gn3.84 (minor) |
Australian Soil Classification: | Bleached-Sodic, Magnesic, Brown CHROMOSOL; thick, slightly gravelly, silty/clayey, deep |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 5.0 | 3 | VL | L | D | D | S | H | VL |
A2 | 4.9 | 15 | VL | VL | D | D | S | VL | L |
B21 | 4.7 | 11 | VL | M | D | D | T | VL | VL |
B22 | 5.0 | 10 | VL | M | D | D | S | VL | L |
Permeability: | Slow (average 15 mm/day, range 10-25 mm/day) |
Available Water Capacity: | High (155 mm H2O) |
Linear Shrinkage (B horizon): | Moderate (17%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T1S3 | Condition of topsoil (A2), permeability-rainfall index |
Effluent Disposal (septic tanks) | 4 | Drainage, slow permeability |
Farm Dams | 3 | Low dispersibility of subsoil, linear shrinkage, permeability, suitability of subsoil, depth to seasonal watertable, depth to hardrock |
Building Foundations slab stumps/footings | 4 4 | Drainage Drainage |
Secondary Roads | 4 | Drainage |
Rural Residential Development | 4 | Secondary roads, effluent disposal, building foundations |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.5 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Moderate | |
Landform Pattern: | Low hills | Drainage: | Imperfectly drained | |
Landform Element: | Drainage depression | Rock Outcrop: | Nil | |
Slope a) common: | 3% | Depth to Hard Rock: | > 1.5 m | |
Slope b) range: | 0-7% | |||
Potential Recharge to Groundwater: | Low | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | Low | Low | Low | Very low | Moderate | Low |
Incidence | Low | Moderate | Low | Very low | Low | NA |
Site S38 | ||
A1 | 0-10 cm | Dark greyish brown (10YR4/2) silty loam, moderate structure, peds 5-10 mm, rough fabric, weak consistence, pH 6.1. Abrupt transition to: |
A2 | 10-40 cm | Very pale brown (10YR7/3) sandy clay loam fine sandy, bleached (10YR8/2) when dry, coarse faint very pale brown mottles are common, weak subangular blocky structure, peds 10-20 mm, rough fabric, firm consistence, very few large subrounded and rounded sedimentary pebbles, pH 6.1. Clear transition to: |
B21 | 40-80 cm | Light yellowish brown (7.5YR5/6) medium clay, many medium faint red and orange mottles, strong polyhedral structure, peds 2-5 mm, smooth fabric, firm consistence, subrounded sedimentary stones are common, pH 5.9. Gradual transition to: |
B22 | 80-110 cm | Yellowish brown (10YR5/4) medium clay, many coarse prominent red mottles and medium faint orange mottles, strong polyhedral structure, peds 20-50 mm, breaking down to 2-5 mm, smooth fabric, firm consistence, pH 6.1. Gradual transition to: |
C | 110-145+ cm | Weathered sedimentary rock. |
Factual Key: | Dy3.41 (major), Gn3.84 (minor) |
Australian Soil Classification: | Bleached-sodic, Magnesic, Brown CHROMOSOL; thick, slightly gravelly, silty/clayey, deep (confidence level 2) |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 5.0 | 3 | VL | L | D | D | S | H | VL |
A2 | 4.9 | 15 | VL | VL | D | D | S | VL | L |
B21 | 4.7 | 11 | VL | M | D | D | S | VL | VL |
B22 | 5.0 | 10 | VL | M | D | D | S | VL | L |
Permeability: | Slow (average 15 mm/day, range 10-25 mm/day) |
Available Water Capacity: | High (160 mm H2O) |
Linear Shrinkage (B horizon): | Moderate (17%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T1S3 | Topsoil condition (A2), permeability-rainfall index |
Effluent Disposal (septic tanks) | 4 | Imperfect drainage, slow permeability |
Farm Dams | 3 | Linear shrinkage, permeability, dispersibility of subsoil, depth to hardrock, suitability of subsoil, depth to seasonal watertable |
Building Foundations slab stumps/footings | 4 4 | Drainage Drainage |
Secondary Roads | 4 | Drainage |
Rural Residential Development | 4 | Secondary roads, effluent disposal, building foundations |
Parent Material Age: | Silurian | Depth to Seas. Watertable: | > 1.5 m | |
Parent Material Lithology: | Sediments | Flooding Risk: | Moderate | |
Landform Pattern: | Low hills | Drainage: | Imperfectly drained | |
Landform Element: | Flat | Rock Outcrop: | Nil | |
Slope a) common: | 1% | Depth to Hard Rock: | > 1.5 m | |
Slope b) range: | 0-1% | |||
Potential Recharge to Groundwater: | Low | |||
Major Native Vegetation Species: | Narrow-leaved Peppermint, Long-leaved Box, Messmate | |||
Present Land Use: | Grazing | |||
Length of Growing Season: | 8 months |
Degradation Processes | Water Erosion | Wind Erosion | Mass Movement | Salting | Acidification | |
sheet/rill | gully | |||||
Susceptibility | Low | Low | Low | Very low | Low | Low |
Incidence | Low | Low | Low | Very low | Low | NA |
Site 38 | ||
A1 | 0-10 cm | Dark greyish brown (10YR4/2) silty loam, moderate structure, peds 5-10 mm, rough fabric, weak consistence, pH 6.1. Abrupt transition to: |
A2 | 10-40 cm | Very pale brown (10YR7/3) sandy clay loam fine sandy, bleached (10YR8/2) when dry, coarse faint very pale brown mottles are common, weak subangular blocky structure, peds 10-20 mm, rough fabric, firm consistence, very few large subrounded and rounded sedimentary pebbles, pH 6.1. Clear transition to: |
B21 | 40-80 cm | Light yellowish brown (7.5YR5/6) medium clay, many medium faint red and orange mottles, strong polyhedral structure, peds 2-5 mm, smooth fabric, firm consistence, subrounded sedimentary stones are common, pH 5.9. Gradual transition to: |
B22 | 80-110 cm | Yellowish brown (10YR5/4) medium clay, many coarse prominent red mottles and medium faint orange mottles, strong polyhedral structure, peds 20-50 mm, breaking down to 2-5 mm, smooth fabric, firm consistence, pH 6.1. Gradual transition to: |
C | 110-145+ cm | Weathered sedimentary rock. |
Factual Key: | Dy3.41 (major), Dy3.81, Dy3.11(minor) |
Australian Soil Classification: | Bleached-Sodic, Magnesic, Brown CHROMOSOL; thick slightly gravelly, silty/clayey, deep (confidence level 2) |
Unified Soil Group: | CH |
Horizon | pH (CaCl2) | % Gravel | EC (salts) | Nutrient Status | P | K | Al | Organic Matter | Dispersibility |
A1 | 5.0 | 3 | VL | L | D | D | S | H | VL |
A2 | 4.9 | 15 | VL | VL | D | D | S | VL | L |
B1 | 4.7 | 11 | VL | M | D | D | T | VL | VL |
B2 | 5.0 | 10 | VL | M | D | D | S | VL | L |
Permeability: | Slow (average 15 mm/day, range 10-25 mm/day) |
Available Water Capacity: | High (160 mm H2O) |
Linear Shrinkage (B horizon): | Moderate (17%) |
Land Use | Class | Major Limiting Feature(s)/Land Use |
Agriculture | C2T1S3 | Condition of topsoil (A2), permeability-rainfall index |
Effluent Disposal (septic tanks) | 4 | Imperfect drainage, slow permeability |
Farm Dams | 3 | Depth to hardrock, linear shrinkage, permeability, low dispersibility of subsoil, suitability of subsoil, depth to seasonal watertable |
Building Foundations slab stumps/footings | 4 4 | Drainage Drainage |
Secondary Roads | 4 | Drainage |
Rural Residential Development | 4 | Secondary roads, effluent disposal, building foundations |