442

Site number:

442

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 side of a ridge and about midslope; about 100m SW and downslope of site 441 on a long even slope

Altitude:

1540 m

Aspect:

S

Slope:

28 °

Climate

Soil climate zone:

Central Mountain

Estimated mean annual temperature:

-35 °C

Frozen ground depth:

75 > cm

Frozen type:

Dry-frozen

Frozen comment:

>75cm

Geology

Geological setting:

Rock outcrops on the area are Ferrar Dolerite; the ground surfaces have been exposed following retreat of ice from the Midnight Plateau; close to the ice edge, the soils appear less weathered but distinct successional surfaces marking ice retreat are not present; with increasing distance away from the ice front, soil weathering increases

Patterned ground:

Nil

Surface weathering or surface features:

The surface is bouldery with clasts greater than 1m; there is strong rounding, cavernous weathering and exfoliation resulting in a subdued surface; the slope is slightly stepped in places suggesting some slow downslope movement of surface materials; the surface rocks are strongly stained; some fine grained rocks are strongly polished; the pavement between larger clasts is moderately developed; some coarse pitting

Soil

Soil parent material:

Exfoliated doleritic debris over till

Previous disturbance:

Nil

Soil weathering stage:

6 5 (Campbell & Claridge 1975)

Soil moisture status:

Thin patchy snow; no thawing or soil moistening observed

Biological activity:

Nil observed