497

Site number:

497

Authors:

IBC, GGC

Date recorded:

1983/01/12

Reason Sampled:

Soil characterisation

Description:

Approximately 8.5km WSW of Larsen Crag, on a moraine mound on the W side of a broad shallow valley, possibly formed by retreat of an earlier inland invasion of ice from the Northwind glacier

Altitude:

1350 m

Aspect:

NE

Slope:

4 °

Climate

Soil climate zone:

Central mountain

Estimated mean annual temperature:

-27 °C

Frozen ground depth:

35 cm

Frozen type:

Hard ice-cemented

Frozen comment:

35cm

Geology

Geological setting:

Northwind Glacier is a southwestward extension of the Fry Glacier and formerly occupied most of the Northwind Valley; within Northwind Valley, dolerite and Beacon group sediments outcrop but there are no known granites; valley floor tills contain appreciable amounts of granite, including the distinctive pink coloured Irizar, indicating a source outside the immediate area

Patterned ground:

Moderately developed nets; weakly active; 30cm deep snow- filled borders

Surface weathering or surface features:

A moderately deflated pebble pavement surface with few upstanding boulders; harder dolerite boulders rounded to subrounded and wind faceted with wind ripples on sublevel surfaces; moderately to strongly stained and polished; coarse dolerite boulders disaggregated; granite erratics crumbling and disaggregating above ground level but firmer below; salts beneath some stones

Soil

Soil parent material:

Till derived from dolerite and Beacon Group sediments with occasional granite boulders

Previous disturbance:

Nil

Soil weathering stage:

6 3 (Campbell & Claridge 1975)

Soil moisture status:

Xerous; numerous small pockets of snow with some thawing and moistening of the soil surface in places

Biological activity:

Occasional patches of yellow lichen in exfoliation cracks