348

Site number:

348

Authors:

IBC, GGC

Date recorded:

1972/12/04

Reason Sampled:

Soil weathering examination

Description:

On the S side of Wright Valley in Sessrumnir Valley, approximately 2.5km NE of Mt Freya; on a valley mouth ridge of moraine; an undulating surface on the west side of the valley

Altitude:

1600 m

Aspect:

NE

Slope:

9 °

Climate

Soil climate zone:

Central Mountain

Estimated mean annual temperature:

-25 °C

Frozen ground depth:

30 cm

Frozen type:

Hard ice-cemented

Frozen comment:

30cm

Geology

Geological setting:

Tills in the alpine valleys of the Asgard Range are among the oldest known in the Transantarctic Mountains and based on ash occurrences, date from the Miocene; the till sequences are complex with local alpine sourced moraine being distinguished from outside sources by the presence of granite erratics; the till at this site has granite erratics indicting a source outside of the local area, most likely from down-valley

Patterned ground:

Weakly developed nets

Surface weathering or surface features:

Coarse grained dolerite boulders are strongly crumbled; granite boulders strongly disggregated; many boulders reduced to ground level; moderately developed ventiforms; a moderately developed pavement surface with distinct to strong clast staining and polish on fine textured rocks; sandstones and some dolerite is cavernously weathered; salts beneath surface stones

Soil

Soil parent material:

Dolerite/sandstone till with granite erratics and other rock types present;

Previous disturbance:

Nil

Soil weathering stage:

6 4 (Campbell & Claridge 1975)

Soil moisture status:

Snow patches only in patterned ground cracks; a few moist patches from thaw of a recent snow fall; salt spots are damp

Biological activity:

Nil observed but endolithic algae present in some sandstone outcrops