352

Site number:

352

Authors:

IBC, GGC

Date recorded:

1972/12/06

Reason Sampled:

Soil weathering examination

Description:

On the S side of Wright Valley in Sessrumnir Valley, approximately 4km N of Mt Freya; on a strongly fractured bedrock sandstone pavement; the sample is from soil material in a fracture between sandstone slabs

Altitude:

1525 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Central Mountain

Estimated mean annual temperature:

-24 °C

Frozen ground depth:

10 > cm

Frozen type:

Frozen comment:

>10cm

Geology

Geological setting:

Flat bedded Beacon Sandstone is exposed without a till cover in places; cryic freeze/thaw weathering processes results in horizontal and vertical fragmentation of the sandstone with tabular blocks moving apart by wedging processes; sandy detritus in cracks is the only soil material developed on these wind swept surfaces

Patterned ground:

Nil; horizontal rock fragmentation pattern is a result of patterned ground type processes

Surface weathering or surface features:

Rock surfaces are polished and oxidised and strongly wind fluted with wind ripple marks; leading edges are strongly abraded

Soil

Soil parent material:

Windblown sand; predominantly quartzitic but with 10% dolerite sand grains

Previous disturbance:

Nil

Soil weathering stage:

6 4 (Campbell & Claridge 1975)

Soil moisture status:

The site is dry; snow sometimes accumulates in the rock cracks

Biological activity:

Nil observed but endolithic algae widely present in sandstone outcrops nearby