Soils on Older Consolidated Sediments

Org - Ordovician Plain | Orr - Ordovician Hills (North) | Ors - Ordovician Steep Hill | Pem - Permian Sediments (Moist ) | Per - Permian Sediments
Pem - Permian Sediments (Moist)

There is only one location of this unit in the Shire of Ballan. It is an isolated outcrop of Permian tillite in the Wombat forest, north-west of Mt. Blackwood. It differs from the other areas of Permian tillite in the survey area by having a wetter climate and deep red soils.

Also the candlebark gum (E. rubida) is replaced by messmate (E. obliqua) in this unit. This area is still forested although part of it is used for rural retreats. The unit only occupies 0.19% of the survey area (1.8 km²)

PEM Red Mottled, Yellow Duplex Soils

Factual Key Dy 3.41/FSL, 25-45/Permian tillite, 50-150

Horizon	Depth (cm)	Description
A1	0-5	Brownish black (10YR 3/2) when moist; fine sandy loam; apedal & massive; consistence when moist is friable; pH 5.0; abrupt boundary.
A2	5-30	Dull yellow orange (10YR 6/3) when moist; with few fine yellow mottles; fine sandy loam; apedal & massive; consistence when moist is firm; pH 5.5; clear boundary.
B1	30-60	Bright yellowish brown (10YR 6/6) when moist; with abundant prominent yellow mottles; light medium clay; weak sub-angular blocky 20 mm; consistence when moist is firm; pH 5.0; abrupt boundary.
B2	60-120	Bright yellow brown (10YR 6/6) when moist; with few distinct red mottled; medium clay; strong angular blocky 4 mm; consistence when moist is firm; pH 5.0; abrupt boundary.
R	120-150	Weathering tillite.

COMPONENT Proportion %	1	2	3
COMPONENT Proportion %	10	80	10
CLIMATE
Rainfall(av.) mm	760 – 810
Temperature(av.) °C	-
Seasonal growth limitations	-
GEOLOGY
Age, rock	Permian tillite
TOPOGRAPHY
Landscape	Broad crests of gentle tillite in the Wombat Forest
Elevation (range) m	570 – 640
Local relief (av.) m	8
Drainage pattern	Dendritic
Drainage density km/km²	0.9
Land form	Undulating Plains
Position on land form	Crest	Slopes	Depression line
Slope (range) %, slope shape	0 – 4; Convex	3 – 15; Convex	1 – 3; Straight
NATIVE VEGETATION
Structure	Open forest
Dominant species	E. obliqua, E. radiata, E. ovata, E. viminalis	E. ovata, E. obliqua, E. radiata, E. viminalis	E. ovata, E. viminalis, E. obliqua, E. radiata
SOIL
Parent material	In-situ weathered rock	In-situ weathered rock	Alluvium-silt, clay sand & quartz
Description	Yellow shallow gradational soils	Red mottled yellow duplex soils	Dark brown gradational soils
Surface texture	Clay loam	Clay loam	Clays
Permeability	Moderate – high	Moderate – high	Moderate – low
Depth (range) m	0.50	1.50	2
LAND USE
	Forestry, urban sub-division (bush blocks)
SOIL DETERIORATION
Critical land features	Slopes	Steep slopes	Moderate permeability, dispersibility
Processes	Overland flow, leaching	Overland flow, leaching	Overland flow, sub-surface flow, waterlogging
Forms	Sheet & rill erosion, nutrient decline	Sheet & rill erosion	Gully erosion, compaction.

Per - Permian Sediments

This unit represents 0.65% of the survey area and covers 6.0 km². The main locations are on the south side of the Greendale fault at Greendale and around Pykes Creek Reservoir. There is one notably poor subdivision on this unit north of Greendale on erodible shallow soils. The unit is mainly used for grazing although parts of it are still timbered. There appears to be a climatic difference between this unit and Pem (Permian Sediments (Moist) in the Wombat forest.

PER Yellow Duplex Soils

Factual Key Dy 3.41/CL-FSCL, 10-30/Permian tillite, 30-120

Horizon	Depth (cm)	Description
A1	0-10	Greyish yellow brown (10YR 4/2) when moist; clay loam, weak sub-angular blocky 2 mm; consistence when slightly moist is friable; pH 6.0; abrupt boundary.
A2	10-20	Dull yellowish brown (10YR 5/4) when moist: with few fine yellow mottles; clay loam; weak sub-angular blocky; consistence when dry is hard, when wet is spewy; pH 6.5; abrupt boundary.
B1	20-50	Yellowish brown (10YR 5/6) when moist; with abundant distinct brown & grey mottles; medium clay; weak sub-angular blocky 50 mm; consistence when dry is slightly hard; pH 6.0; clear boundary.
B2	50-100	Orange (7.5YR 6/6) when moist; with abundant prominent grey & red mottles; medium clay; weak sub-angular blocky 50 mm breaking down to strong angular blocky 2 mm; consistence when dry is hard; pH 6.0; clear boundary.
C	100+	Weathering tillite gravelly clay.

COMPONENT Proportion %	1	2
	95	5
CLIMATE
Rainfall(av.) mm	685 – 736
Temperature(av.) °C	-
Seasonal growth limitations	-
GEOLOGY
Age, rock	Permian tillite
TOPOGRAPHY
Landscape	Hills in the Greendale area
Elevation (range) m	390 – 500
Local relief (av.) m	12
Drainage pattern	Dendritic
Drainage density km/km²	0.8
Land form	Undulating plains
Position on land form	Crests, gentle slopes & lower slopes	Scarps & steep slopes
Slope (range) %, slope shape	2 – 10; Convex	15 – 35; Straight
NATIVE VEGETATION
Structure	Open forest
Dominant species	E. rubida, E. ovata, E. radiata, E. viminalis
SOIL
Parent material	In-situ weathered rock
Description	Yellow duplex soil	Yellow, shallow, gravelly gradational soils
Surface texture	Loam	Clay loam
Permeability	Moderate – low	Moderate
Depth (range) m	1	0.5
LAND USE
	Grazing, urban sub-division
SOIL DETERIORATION
Critical land features	Hard setting surfaces, drainage	Slopes, dispersibility, hard setting surfaces
Processes	Overland flow	Overland flow, sub-surface flow, seepage
Forms	Sheet erosion	Severe landslips, sheet, rill & gully erosion

Org - Ordovician Plain

This unit consists of the gentler Ordovician country and has been separated from Ors on the basis of slope, vegetation, and soils. The unit is scattered down the east and west sides of the Shire and occupies 5.4% of the survey area (50.1 km²). It is mainly used for grazing and cereal cropping but. some parts are still forested

ORG Red Mottled, Yellow Duplex Soils

Factual Key Dy 3.41/CL-L, 10-40/Weathering Ordovician Sediments

Horizon	Depth (cm)	Description
A1	0-10	Brownish black (10YR 3/2) when moist; clay loams; apedal & massive; consistence when dry is hard; pH 5.8; sharp boundary.
A2	10-30	Greyish yellow brown (10YR 4/2) when moist; clay loam; apedal hydrophobic massive; consistence when dry is very hard; pH 5.8; sharp boundary.
B	30-150	Yellowish brown (10YR 5/6) when moist; red mottling; medium clay; strong angular blocky 2 mm; consistence when dry is very hard; pH 5.5; with 4% gravel.

COMPONENT Proportion %	1	2	3
COMPONENT Proportion %	10	85	5
CLIMATE
Rainfall(av.) mm	630 - 760
Temperature(av.) °C	-
Seasonal growth limitations	-
GEOLOGY
Age, rock	Ordovician, slate & sandstone
TOPOGRAPHY
Landscape	Slightly dissected plain
Elevation (range) m	421
Local relief (av.) m	10
Drainage pattern	Dendritic
Drainage density km/km²	3.9
Land form	Rolling plain
Position on land form	Crest	Long gentle slope	Drainage line
Slope (range) %, slope shape	1 – 3; Convex	3 – 9; Straight	1 – 3; Concave
NATIVE VEGETATION
Structure	Woodland	Open forest
Dominant species	E. obliqua, E. radiata	E. viminalis, E. obliqua	E. ovata, E. obliqua
SOIL
Parent material	In-situ weathered rock	In-situ weathered rock	Alluvium clay, silt, sand and gravel
Description	Shallow stony red gradational soil	Red mottled yellow duplex soil	Mottled yellow & red gradational soil
Surface texture	Gravelly loam	Loamy clay	Clay loam
Permeability	High	Moderate – Low	Low – Moderate
Depth (range) m	0.6	1	2
LAND USE
	Grazing with some forestry and cropping (cereal)
SOIL DETERIORATION
Critical land features	Hard setting surfaces, dispersibility	Hard setting surfaces	Moderate dispersibility, poorly drained site, hard setting surfaces
Processes	Overland flow, leaching of salts	Overland flow, leaching of salts	Overland flow, accumulation of salts
Forms	Sheet and rill erosion, compaction	Sheet and rill erosion, gully erosion, compaction	Salting, gully erosion

Ors - Ordovician Steep Hill

This unit consists of steep Ordovician hills and deeply incised valleys scattered throughout the survey area. A good example of this unit is the steep portion of the Brisbane Ranges on the west side of the Rowsley Fault. The main land use is forestry which is also the most Suitable use as this unit is highly erodible. Some parts of the unit are used for grazing. The unit occupies 10.67% of the Shire and covers an area of 98.9 km².

Red Mottled, Yellow Gradational Soils Fine Structure

Factual Key Gn 3.71/CL, 5-15/Weathered ordovician sediments 30-100

Horizon	Depth (cm)	Description
A	0-8	Brown (7.5YR 4/3) when moist; gravelly clay loam; apedal, massive & hydrophobic; consistence when dry is hard; pH 5.5; diffuse boundary.
B1	8-30	Bright reddish brown (5YR 5/6) when moist with abundant red brown mottles; light medium clay; moderate angular blocky 3 mm; consistence when moist is firm; pH 5.8; diffuse boundary with colluvial stones.
B2	30-50	Reddish brown (5YR 4/6) when moist with abundant red mottles; medium clay; strong angular blocky 3 mm; consistence when moist is firm; pH 6.0; diffuse boundary.
B/C	50-60	As B2 with 60-80% weathering. Ordovician sedimentary rock.
R	60+	Ordovician rock.

COMPONENT Proportion %	1	2	3	4
COMPONENT Proportion %	2	48	3	45
CLIMATE
Rainfall(av.) mm	660 – 710
Temperature(av.) °C	-
Seasonal growth limitations	-
GEOLOGY
Age, rock	Ordovician, slates and sandstones
TOPOGRAPHY
Landscape	Hilly areas throughout the Shire
Elevation (range) m	425
Local relief (av.) m	65
Drainage pattern	Dendritic
Drainage density km/km²	7.6
Land form	Hill
Position on land form	Moist protected slopes	Dry exposed slopes	Drainage line	Crest
Slope (range) %, slope shape	15 ; Straight	15 ; Straight	3 ; Concave	3 ; Convex
NATIVE VEGETATION
Structure	Tall open forest	Open forest
Dominant species	E. obliqua, E. ovata, E. radiata, E. viminalis	E. dives, E. obliqua, E. viminalis, E. radiata	E. radiata, E. viminalis, E. obliqua	E. obliqua, E. dives, E. viminalis, E. radiata
SOIL
Parent material	In-situ weathered rock	In-situ weathered rock	Alluvium, clay, silt, sand, gravel	In-situ weathered rock
Description	Red mottled yellow gradational or duplex soils, fine structure	Red mottled yellow gradational or duplex soils, fine structure	Black gradational soil (variable)	Shallow stony red & yellow gradational soil
Surface texture	Fine sandy loam	Fine sandy loam	Clay loam	Gravelly loam
Permeability	High	High	Moderate – Low	High
Depth (range) m	1	1	>1	0.5
LAND USE
	Mainly forestry, grazing
SOIL DETERIORATION
Critical land features	Steep slopes, hard setting surfaces	Steep slopes, hard setting surfaces	Moderate permeability, hard setting surfaces, dispersibility	Moderate slopes, hard setting surfaces
Processes	Overland flow	Overland flow	Overland flow, subsurface flow, waterlogging	Overland flow
Forms	Sheet and rill erosion	Sheet and rill erosion, compaction	Gully erosion, compaction	Sheet and rill erosion, compaction

Orr - Ordovician Hills (North)

This is the second largest unit in the survey area, occupying 25.45% of the Shire and covering 236.0 km². It is located to the north of the Greendale fault and is used for softwood plantations, forestry, recreation, mining, water supply protection, grazing and some cereal cropping. The erosion hazard of this unit is high and therefore careful management is required. Scattered throughout the unit are patches of Gn or Dr finely pedal red soils (Component 2) which may owe the origins to remnants of Tertiary, iron rich soils. The presence of fragments of fractured ferricrete are often associated with these profiles. These soils are more permeable and stable than the yellow soils.

Yellow Duplex Soil

Factual Key Dy 3.41/FSL, 10-30/Weathered slates, 80-150.

Horizon	Depth (cm)	Description
A1	0-15	Brownish black (10YR 3/1) when moist; fine sandy loam; apedal and massive; consistence when slightly moist is firm; pH 5.0; clear boundary.
A2	15-20	Greyish yellow brown (10YR 5/2) when moist; and dull yellow orange (10YR 7/2) when dry; fine sandy loam; apedal and massive; consistence when slightly moist is firm; pH 5.0; abrupt boundary.
B1	20-40	Dull yellow orange (10YR 6/3) when moist; light clay; moderate sub-angular blocky 3mm; consistence when slightly moist is firm; pH 5.5; clear boundary.
B2	40-100	Dull yellow orange (10YR 1/3) when moist; faint and distinct red brown mottle; silty clay; strong angular blocky 3mm; consistence when slightly moist is firm; pH 5.5; clear boundary.
C	100+	Weathering slates.

COMPONENT Proportion %	1	2	3	4
COMPONENT Proportion %	20	15	60	5
CLIMATE
Rainfall(av.) mm	760 – 1000
Temperature(av.) °C	-
Seasonal growth limitations	-
GEOLOGY
Age, rock	Ordovician, slates and sandstone
TOPOGRAPHY
Landscape	Hills at northern end of Shire
Elevation (range) m	670
Local relief (av.) m	45
Drainage pattern	Dendritic
Drainage density km/km²	5.9
Land form	Hills
Position on land form	Crest & steep slopes	Slopes with deep soil	Slopes with shallow soil	Drainage line
Slope (range) %, slope shape	5 – 20; Convex	5 – 20; Straight	5 – 30; Straight	1 – 4 ; Concave
NATIVE VEGETATION
Structure	Open forest
Dominant species	E. radiata, E. dives, E. rubida, E. obliqua	E. viminalis, E. obliqua, E. radiata, E. rubida (some E. cypellocarpa)	E. obliqua, E. radiata, E. rubida, E. dives, E. viminalis	E. ovata, E. obliqua, E. rubida, E. radiata
SOIL
Parent material	In-situ weathered rock	In-situ weathered rock	In-situ weathered rock	Alluvium, colluvium clay, silt, sand and gravel
Description	Shallow stony brown gradational soils	Red duplex and red gradational soils, fine structure	Yellow duplex and yellow gradational soils	Brown gradational soil
Surface texture	Gravelly loam	Fine sandy loam to Clay loam	Fine sandy loam to Clay loam	Clay loam
Permeability	High	High	Moderate – High	Moderate
Depth (range) m	0.5	2	1	2
LAND USE
	Soft wood plantations, some grazing, cropping
SOIL DETERIORATION
Critical land features	Steep slopes	Slopes	Slopes	Moderate permeability, dispersibility
Processes	Overland flow, leaching	Overland flow, leaching	Overland flow, leaching	Overland flow, subsurface waterlogging
Forms	Sheet & rill erosion, nutrient decline	Sheet erosion, nutrient decline	Sheet & rill erosion, nutrient decline	Gully erosion, compaction

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