349

Site number:

349

Authors:

IBC, GGC

Date recorded:

1972/12/05

Reason Sampled:

Soil weathering examination

Description:

On the S side of Wright Valley in Sessrumnir Valley, approximately 2km NNE of Mt Freya; near the N end of a high valley shoulder surface; the site on the upper part of a broad rising slope, about 250m from the upper bench-like surface

Altitude:

1675 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Central Mountain

Estimated mean annual temperature:

-26 °C

Frozen ground depth:

54 cm

Frozen type:

Hard ice-cemented

Frozen comment:

54cm

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 is above the granite erratic moraine and appears to be of local origin

Patterned ground:

Nil at site

Surface weathering or surface features:

Dolerite boulders mostly rounded with some ventiform shapes and also strong pitting in fine grained clasts; some dolerite cavernously weathered; coarse dolerite with granular disintegration; sandstone clasts strongly stained and fretted to rubble; salts beneath surface stones

Soil

Soil parent material:

Bouldery till from dolerite and sandstone

Previous disturbance:

Nil

Soil weathering stage:

6 4/5 (Campbell & Claridge 1975)

Soil moisture status:

A dry site but small scattered snow remnants; no evidence of thawing or soil moistening

Biological activity:

Nil observed but endolithic algae present in some sandstone outcrops