GL98

Site: GL98	Land Unit: Marl
*Aust. Soil Class.:* Ferric, Petrocalcic, Black DERMOSOL (confidence level 1)

Soil pit GL98 auger

General Land Unit Description:
This land unit is a complex consisting of mainly gently undulating to level plains with numerous small depressions. In the more undulating portion of the unit, the very slight rises with broad level crests have soils consisting of Dermosols (GL98) or Chromosols (GL70). The soils are variable, some soils have soft carbonate nodules at depth, some have ferruginous nodules and some exhibit vertic (cracking) characteristics. There are also minor occurrences of sand hills and dunes consisting of deep, uniform sands (Tenosols, Podosols). The numerous small depressions are commonly alkaline grey or black cracking clays (Vertosols). A minor soil type in some depressions are acidic black cracking clays (Vertosols) and some shallow soils. The soils in the western portion of the land unit tend to have poorer internal drainage than soils of the eastern zone. The major restriction for land use is the poor internal drainage and the variable soils within a short distance. This soil type is used as the major soil type representing this complex unit. It is located on the plains.

Site Description:

Slope: 3%	Geology: Tertiary marl
Landform pattern: Level plain	Position in landscape: Flat
Internal drainage: Moderately well drained

Soil Profile Morphology

A1	0-10 cm	Black (10YR2/1) loam, weak subangular blocky structure (5-15 mm), strong consistence when dry, pH 6.3. Transition to:
A3	10-30 cm	Black (10YR2/1) clay loam, weak subangular blocky structure (10-20 mm), strong consistence when dry, pH 6.2. Transition to:
	Subsoil
B11	30-40 cm	Very dark grey (10YR3/1) light clay, few very faint yellow mottles, weak to massive subangular blocky structure (20+ mm), pH 6.4. Transition to:
B12	40-80 cm	Very dark greyish brown (2.5Y3/2) light clay, many distinct yellow, orange and black mottles, weak prismatic structure (20+ mm), pH 6.8. Transition to:
B2	80-150 cm	Light olive brown (2.5Y5/4) medium clay, many yellow, orange and black mottles, weak subangular blocky structure (2-10 mm), ferruginous nodules are abundant occurring as a 50 mm layer above clay, many organic segregations, a few soft calcium carbonate nodules, pH 7.3. Transition to:
B3	150-160 cm	Pale yellow (2.5Y7/4) heavy clay, weak angular blocky structure (10-15 mm), soft calcium carbonate nodules are common, pH 8.0.

Key profile features:

Ferric horizon
Alkaline at depth
Clacium carbonate nodules at depth
Mottled subsoil

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