621

Site number:

621

Authors:

IBC, GGC, MRB

Date recorded:

1991/11/23

Reason Sampled:

Soil water rate of loss investigation

Description:

Approximately 4.6km NW of Marble Point peninsula and W of the Marble Point Air Facility; about 100m from the Wilson Piedmont Glacier; on a surface adjacent to a small thawing snow patch; the samples were collected daily on a transect line parallel to and 1m distance from the thawing snow front, to measure the rate at which water was lost from the soil after being moistened by thee adjacent thawing snow

Altitude:

65 m

Aspect:

N

Slope:

4 °

Climate

Soil climate zone:

Coastal Antarctic

Estimated mean annual temperature:

-18 °C

Frozen ground depth:

0 cm

Frozen type:

Frozen comment:

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

Patterned ground:

Weakly developed 20m nets; 5cm troughs with active open cracks

Surface weathering or surface features:

A predominantly pebble gravel pavement; non to weakly stained

Soil

Soil parent material:

Sandy gravel till from predominantly granitic rocks

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:

The soil is moist adjacent to the small snow patch which was retreating; as the snow front retreated, soils on the transect line became dry

Biological activity:

Nil at site; moss patches and cyanobacteria are common locally