445

Site number:

445

Authors:

IBC, GGC

Date recorded:

1978/11/19

Reason Sampled:

Soil weathering examination

Description:

The Darwin Mountains, just to the south of the Midnight Plateau; the site is on the floor of a depression that has been formed by moraine deposition at the former mouth of a small valley; the basin floor is about 70m across and the sample site is near the centre

Altitude:

1600 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Central Mountain

Estimated mean annual temperature:

-30 °C

Frozen ground depth:

36 > cm

Frozen type:

Frozen comment:

>36cm

Geology

Geological setting:

The rocks of the area are Ferrar Dolerite; the ground surfaces have been exposed after retreat of ice from the Midnight Plateau; subsequent up-valley ice invasion has deposited valley mouth granitic till; the basin floor may have previously been a wet salty hollow

Patterned ground:

Nil

Surface weathering or surface features:

Fine grained clasts are moderately to strongly stained but larger coarse grained clasts have a grey and fresh appearance, typical of surface corrosion in wet and salty sites; some pitting of fine grained dolerite; a moderately to strongly developed pavement with some ventiforms

Soil

Soil parent material:

Till from dolerite and sandstone; possibly some reworked as sediment

Previous disturbance:

Nil

Soil weathering stage:

6 4 (Campbell & Claridge 1975)

Soil moisture status:

Small scattered snow patches but no thawing observed; the soil is moist below the surface

Biological activity:

Nil observed