LSWW23

Location: Harrow

Australian Soil Classification: Melanic, Black FERROSOL / DERMOSOL (confidence level 4).
General Landscape Description: Rise
Site Description: Hillslope
Geology: Hypatia Formation: flows and plugs of various basalt forms

General Land Unit Description: There are a few isolated outcrops of Jurassic trachyte in the north-western portion of the study area, with the largest outcrop being north east of Coleraine. There are also some colluvial slopes on the edge of trachyte outcrops around the Dundas and Merino Tablelands.

The trachyte hills often have rock outcrop and reasonably shallow soils on the crests and upper slopes. The main soil type on the upper slopes is a Brown Sodosol although Chromosols also occur and they are commonly sodic at depth. The soils on the colluvial slopes tend to be black cracking clays (Vertosols) or Black Vertic Sodosols. These soils are similar to the black soils of the dissected Merino Tablelands land unit. The soils on these slopes are a complex mix of different soil forming processes.

This site is on the steeply dissected hills and rises leading to the Glenelg River and it’s tributaries. Trachyte is often found outcropping through the Tertiary sediments and in association with older sediments and granite. Due to the steep slopes the lower slopes often have an accumulation of colluvial material deposited on top.

Exposed basalt near Harrow

Horizon	Depth (cm)
A1	0–10	Very dark grey (2.5Y3/1); light clay; strong medium, parting to strong fine blocky structure; strong consistence, dry; pH 6.5; changes to:
Subsoil
B21	10–40	Very dark grey (10YR3/1); light clay; strong medium polyhedral, parting to strong fine blocky structure; very strong consistence, dry; pH 6.9; changes to:
B22	40–70	Very dark grey (10YR3/1); heavy clay; strong angular coarse blocky, parting to strong fine polyhedral structure; very strong consistence when dry; pH 7.3.
B23	70–120	Light olive brown (2.5Y5/3) with many dark grey and yellow brown mottles; heavy clay, strong angular coarse blocky, parting to strong fine polyhedral structure; very strong consistence when dry; pH 7.9.
B24	120–175+	Light olive brown (2.5Y5/3) with many mottles; heavy clay; strong angular coarse blocky, parting to strong fine polyhedral structure; very strong consistence when dry; few ferruginous nodules.

Horizon	Horizon Depth (cm)	pH (water)	pH (CaCl2)	EC dS/m	Coarse Sand (0.2-2.0 mm) %	Fine Sand (0.02-0.2 mm) %	Silt (0.002-0.02 mm) %	Clay (<0.002 mm) %	Wilting Point % w/w
A1	0–10	6.5	5.7	0.08	6.4	12.5	20	52.5	15.9
B21	10–40	6.9	5.7	<0.05	4.9	10.6	18.5	61	17.5
B22	40–70	7.3	6.1	<0.05	5.4	9.5	14.5	65	18.5
B23	70–120	7.9	6.9	<0.05
B24	120–175+

• Uniform clay soil.
• Strong structure throughout. Could be a self mulching Vertosol. Strong structure and organic matter make it feel lighter
• Slightly acid surface soil grades into neutral to alkaline subsoil
• Mottling in the deeper subsoil.
• Hillslope, well drained site drainage