346

Site number:

346

Authors:

IBC, GGC

Date recorded:

1972/12/03

Reason Sampled:

Soil weathering examination

Description:

On the S side of Wright Valley in Sessrumnir Valley, approximately 2.3km NE of Mt Freya; on a slightly hummocky moraine ridge surface on the valley floor, south of the valley mouth moraine which contains granite clasts

Altitude:

1525 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Central Mountain

Estimated mean annual temperature:

-25 °C

Frozen ground depth:

18 cm

Frozen type:

Hard ice-cemented

Frozen comment:

18cm

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; alpine glaciers probably persisted and interacted with periodic invasions of ice from the Wright Valley

Patterned ground:

Weakly developed nets

Surface weathering or surface features:

A well developed cobble and pebble pavement with few upstanding boulders; many distinct ventiforms; distinct staining on lee surfaces but exposed surfaces abraded; salts beneath surface stones

Soil

Soil parent material:

Sandy grave from sandstone and dolerite with sandy to silty stony till alongside; the sandy material may be an old sand wedge

Previous disturbance:

Nil

Soil weathering stage:

6 3/4 (Campbell & Claridge 1975)

Soil moisture status:

Soil dry; some small snow patches in the area

Biological activity:

Nil observed but endolithic algae present in some sandstone outcrops