711

Site number:

711

Authors:

IBC, GGC

Date recorded:

1993/01/05

Reason Sampled:

Cape Roberts soil examination for the CEE for the proposed McMurdo Sound Stratigraphic Drilling project

Description:

The site is located at the northern end of a gently sloping, fine gravelly area and a little to the north of the site of existing NZAP huts

Altitude:

4 m

Aspect:

S

Slope:

4 °

Climate

Soil climate zone:

coastal Antarctic

Estimated mean annual temperature:

-17 °C

Frozen ground depth:

52 cm

Frozen type:

ice-cemented

Frozen comment:

52

Geology

Geological setting:

The rocks of the area are granodiorites that have been largely planed by ice movement then subject to some weathering processes by beach and wave action; isostatic uplift has resulted in beach terracing with the raised beaches comprising mainly coarse boulder gravels; some schist/gneiss and occasional dolerite clasts in the beach gravels are indicative of residual tills; bedrock outcrops widely forming an in situ large bouldery surface; fine gravel deposits occupy a small area only

Patterned ground:

some weak patterned ground formation with shallow ill- defined cracks

Surface weathering or surface features:

bright oxide staining in patches on some surface rocks; some slight exfoliation; clasts mainly rounded to subrounded due to beach abrasion

Soil

Soil parent material:

unweathered sandy gravel beach deposits from dominantly granodiorite and gneissic rocks

Previous disturbance:

the site has been subjected to low levels of disturbance from previous activities at Cape Roberts;

Soil weathering stage:

6 1 (Campbell & Claridge 1975)

Soil moisture status:

oceanic subxerous

Biological activity:

not active at the profile site apart from some slight algal crusting; abundant algal and some moss accumulations in other places where water is abundant; Skuas are abundant and the ground surface has noticable accumulations of guano