631

Site number:

631

Authors:

IBC, GGC, MRB

Date recorded:

1991/11/29

Reason Sampled:

Soil moisture and permafrost investigation; examination on beach ridge surfaces of differing ages

Description:

Approximately 150m from the coast in Arnold Cove; east from the S end of the Marble Point Air Facility; on the second clearly defined raised beach surface; a narrow ridge surface with a 10m 1o backslope and a 10o foreslope; on the crest of the ridge

Altitude:

20 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Coastal Antarctic

Estimated mean annual temperature:

-18 °C

Frozen ground depth:

38 cm

Frozen type:

Hard ice-cemented

Frozen comment:

38cm

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, marble with kenyite in places; surface boulders are well rounded but clasts below the surface are subangular; sorting due to beach processes may only have been superficial

Patterned ground:

Weakly developed rectangular nets with 20cm deep troughs; some troughs closed with sand fillings

Surface weathering or surface features:

Bouldery gravel; many granodiorites have distinct oxidation

Soil

Soil parent material:

Weakly sorted sandy bouldery gravel of mixed lithology; some shell fragments present

Previous disturbance:

Human visitation with some old soil pit sites

Soil weathering stage:

1 (Campbell & Claridge 1975)

Soil moisture status:

A dry site with no thaw seepages; residual snow in adjacent hollows; no soil moistening evident

Biological activity:

Nil at site; moss patches and cyanobacteria are common locally