630

Site number:

630

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 200m from the coast in Arnold Cove; ENE from the S end of the Marble Point Air Facility; on the uppermost clearly defined raised beach surface; a hummocky narrow ridge surface on the crest of the ridge

Altitude:

30 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Coastal Antarctic

Estimated mean annual temperature:

-18 °C

Frozen ground depth:

48 cm

Frozen type:

Hard ice-cemented

Frozen comment:

48cm

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:

Hummocky rectangular nets, 3m across with 25cm deep troughs

Surface weathering or surface features:

Surface clasts are subrounded; numerous pebbles and cobbles showing some oxide staining on all sides; some exfoliation and fragmentation; very strong granular disintegration of marble; the near coastal (salty) environment appears to encourage more extensive surface oxidation

Soil

Soil parent material:

Weakly sorted sandy bouldery gravel of mixed lithology

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