634

Site number:

634

Authors:

IBC, GGC, MRB

Date recorded:

1991/11/30

Reason Sampled:

Soil weathering examination of a rock sample on a raised beach surface

Description:

Approximately 90m from the coast in Arnold Cove; east from the S end of the Marble Point Air Facility; just below the crest of the third from the topmost distinct beach ridge surface

Altitude:

15 m

Aspect:

E

Slope:

8 °

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 Marble Point beach ridges are a well defined set of raised beaches; they are though to have formed due to isostatic uplift; the age may range from 10,000 years; the lithology is mixed granite, gneiss, granodiorite marble with kenyite in places; some boulders are oxidised and partly crumbled

Patterned ground:

Indistinct net pattern with shallow sand-filled inactive cracks

Surface weathering or surface features:

Surface boulders and cobbles rounded but subsurface clasts at lower depth are subangular; granite boulders are disintegrating and some granodiorite clasts are distinctly oxidised and partly crumbly; the oxidation intensity appears to increase with proximity to the coast and may be a result of marine influence

Soil

Soil parent material:

Oxidised granodiorite boulder

Previous disturbance:

Human visitation with some old soil pit sites

Soil weathering stage:

3 (Campbell & Claridge 1975)

Soil moisture status:

A dry site, no adjacent snow or soil moistening

Biological activity:

Nil at site; moss patches and cyanobacteria are common locally