501

Site number:

501

Authors:

IBC, GGC

Date recorded:

1983/01/14

Reason Sampled:

Soil characterisation

Description:

Approximately 1km from the SW end of the Northwind Glacier, in a deep landscape depression; the site is close to a small saline pond which has extensive salt encrustations immediately adjacent to, and below the water line; the site is midway between the edge of the pond and the upper level of the salt encrusted surface; the depression (>1km across) is a glacially formed hole similar to that found in other places in Antarctica

Altitude:

475 m

Aspect:

N

Slope:

2 °

Climate

Soil climate zone:

Central mountain

Estimated mean annual temperature:

-23 °C

Frozen ground depth:

30 > cm

Frozen type:

Frozen comment:

>30cm

Geology

Geological setting:

The large depression formed in dolerite has possibly formed through glacial scour by ice coming from a previously enlarged Polar Plateau Ice Sheet; there have been subsequent ice advances from NE filling much of the Northwind Valley; the latest ice advances have retreated down valley leaving successively younger surfaces; the lower altitude surfaces of the Northwind Valley have deposits of young till that have been proglacially reworked as well as freshly exposed, little fractured bedrock

Patterned ground:

Nil

Surface weathering or surface features:

Salt encrustations are thick close to the water level covering boulders as well as fine soil material; salt encrusted rocks are unstained but beyond the saline zone, there is weak staining on surface rocks

Soil

Soil parent material:

Fluvially reworked doleritic till

Previous disturbance:

Nil

Soil weathering stage:

6 2 (Campbell & Claridge 1975)

Soil moisture status:

Xerous to subxerous; the soil is >1m above an unfrozen pond and is moist throughout

Biological activity:

Algae are absent in this highly saline pond but are present in an adjacent less saline lake