GL100

Site: GL100	Land Unit: Merino Tablelands
*Aust. Soil Class.:* Melanic, Subnatric, Brown SODOSOL (confidence level 1)

Soil pit GL99 landscape

Soil pit GL100 auger

General Land Unit Description:
This unit consists of the Cretaceous non-marine sandstone of the dissected Merino Tablelands. The tablelands were thought to have formed under swamp conditions and a warm climate. As a result, the soils tend to be high in clay and there tends to be carbon rich seams of charcoal deposits at depth in some of the profiles. The main soil type used to represent this land unit is black cracking clays (Vertosols) that can be sodic at depth. This soil type, along with Black Sodosols, Chromosols and Dermosols, are commonly found on the broad crests or drainage lines. The slopes often consist of Brown Chromosols, Sodosols or Dermosols, although black soils can also occur on the slopes. The lower slopes commonly have Grey Vertosols or Sodosols as the major soil type. The reasonably deep sodic soils on short steep slopes tend to be prone to landslips. The grey soils, in particular are prone to water erosion.

Site Description:

Slope:10%	Geology: Cretaceous non-marine sandstone
Landform pattern: Rises, low hills	Position in landscape: Upper slope
Internal drainage: Imperfectly drained

Soil Profile Morphology

A1	0-20 cm	Very dark brown (10YR2/2), clay loam, strong subangular blocky structure (2-5 mm), very firm consistence when dry, very few sedimentary fragments, pH 5.8; transition to:
	Subsoil
B21	20-40 cm	Dark brown (10YR3/3), light medium clay, medium to strong columnar to subangular blocky structure (10-20 mm), very firm consistence when dry, pH 6.2; transition to:
B22	40-60 cm	Dark brown (10YR3/3), medium clay, orange mottles are common, weak to medium subangular blocky structure, very firm consistence when moderately moist, pH 7.3; transition to:
B23	60-80 cm	Brown (10YR4/3), medium heavy clay, many light brown mottles, weak to medium subangular blocky structure, very firm consistence when moderately moist, pH 8.3;
B3	80-95 cm	Light olive brown (10YR5/4), fine sandy light clay, very firm consistence when moderately moist, pH 9.1; transition to:
BC	95-105 cm
C	105+ cm

Key profile features:

Alkaline subsoil
Sodic subsoil
Mottled subsoil
Topsoil dispersive when worked when wet
Top of subsoil dispersive when worked when wet

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