DYS99 (Plot 3)

Site: DYS99 (Plot 3)

Land Unit: Strathdownie

General Land Unit Description:

This land unit comprises the Quaternary lacustrine geology south of the Glenelg River. The lacustrine deposits include lagoonal, swamp and local colluvial deposits formed in low-lying wetlands and depressions between stranded beach ridges. Parent material in this land unit comprises of sand, silt, sandy clay, peat, marl and freshwater limestone, occurring in relatively unconsolidated forms.

The soils are variable throughout this land unit due to varying depositional environments. A common soil type is a strong texture contrast soil (Chromosol) commonly with a bleached A2 horizon and a mottled subsoil (indicative of impeded internal drainage). The sandy topsoil can be very deep in some soils. Vertosols are also common on the plains and swales in between the dunes. Podosols occur on the flats as well as on the dunes and that may have been mapped as part of this land unit due to restrictions of scale. Many of the soils are poorly drained and exhibit signs of a perched watertable.

This site has a 1.5 year old

Eucalyptus globulus

plantation on ex-agricultural land. The site is probably a heathland/bog. The trees in this plot have been severely affected by waterlogging.

Site Description:

Geology: Quaternary lacustrine	Landform pattern: Plain
Position in landscape: Flat	Internal drainage: Poorly drained

Soil Profile Morphology

A1	0-20 cm	Very dark greyish brown (10YR3/2) clay loam; weak angular blocky structure (10-20 mm); firm consistence when dry; few medium ferruginous nodules; many fine macropores; areal porosity 0.7%; common medium roots; clear and smooth transition to:
Subsoil
B1	20-35 cm	Greyish brown (10YR5/2) with many medium faint yellowish brown (10YR5/4) and yellowish red (5YR4/6) mottles, light clay; weak angular blocky structure (20-50 mm); weak consistence when moderately moist; few medium ferruginous nodules; many fine macropores; areal porosity 0.5%; few very fine roots; clear and smooth transition to:
B21	35-60 cm	Greyish brown (10YR5/2) with many medium faint yellowish brown (10YR5/4) and brownish yellow (10YR6/8) mottles, medium clay; moderate polyhedral structure (20-50 mm) parting to strong polyhedral structure (10-20 mm); weak consistence when moderately moist; few medium ferruginous nodules; many very fine macropores; areal porosity 0.3%; few very fine roots; diffuse and smooth transition to:
B22	60-85 cm	Light yellowish brown (10YR6/4) with many medium faint brownish yellow (10YR6/8) and light grey (10YR7/1) mottles, medium clay; moderate polyhedral structure (20-50 mm) parting to moderate granular structure (2-5 mm); weak consistence when moderately moist; many very fine macropores; areal porosity 0.1%; few very fine roots; diffuse and smooth transition to:
B23	85-150 cm	Light grey (10YR7/1) with many medium distinct brownish yellow (10YR6/8) and yellowish red (5YR5/8) mottles, medium heavy clay; strong lenticular structure (50-100 mm) (slickensides) parting to strong polyhedral structure (5-10 mm); weak consistence when moist; common very fine macropores; areal porosity 0.05%; few very fine roots (along cracks to 110 cm).
	150-180 cm	Similar to layer above.
	180-310 cm	Grey heavy clay (slickensides) with light red mottles and iron concretions.
	310-390 cm	Grey heavy clay with yellow mottles and limestone segregations, no remnant roots observed.

Notes: Sampled by: Ian Sargeant and Paul Feikema (13 December 2000)

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