614

Site number:

614

Authors:

IBC, GGC, MRB

Date recorded:

1991/11/21

Reason Sampled:

Permafrost and soil moisture examinations

Description:

Approximately 4.4km NW of Marble Point peninsula and approximately 400m W of the Marble Point Air Facility; about 100m from the Wilson Piedmont Glacier; on the crest of a slight rise between two depressions

Altitude:

75 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Coastal Antarctic

Estimated mean annual temperature:

-18 °C

Frozen ground depth:

35 cm

Frozen type:

Hard ice-cemented

Frozen comment:

35cm

Geology

Geological setting:

The surface is a gently undulating till plain formed by retreat of the Wilson Piedmont Glacier; the Marble Point region is an old landscape, with deposits of phillipsite, buried soils and oxidised gneiss, which have been covered by advances of the grounded Ross Ice Shelf; later ice retreat and glaciological features have been controlled by changes in the stranded Wilson Piedmont Glacier; the till mantle is patchy and dominated largely by locally occurring rocks; granodiorite, granite, marble, gneiss, and dolerite are the main rock types present

Patterned ground:

Weakly developed 20-25m nets; 5-10cm troughs with open cracks

Surface weathering or surface features:

Surface boulders are angular with some slight surface staining; some smaller clasts moderately oxidised; active exfoliation and fragmentation of granular clasts; a few surface salt efflorescences

Soil

Soil parent material:

Sandy gravel till from mixed granite, gneiss and marble

Previous disturbance:

Extensive mechanical and human activity in the region since the mid-1950's

Soil weathering stage:

1 (Campbell & Claridge 1975)

Soil moisture status:

A dry site with no surface water flows; no snow cover, snow thaw or soil moistening

Biological activity:

Nil at site but locally moss and algae in damp or wet sites