704

Site number:

704

Authors:

IBC, GGC

Date recorded:

1993/12/30

Reason Sampled:

assessment of environmental impacts from past human activities at Vanda Station; this site was sampled from a relatively undisturbed area upwind from Vanda Station to allow comparisons to be made with disturbed sites

Description:

approximately 340m southwest of Vanda Station and about 20m to the west of site 703 but on a ridge surface formed from lamprophyre dyke rock

Altitude:

98 m

Aspect:

Slope:

0 °

Climate

Soil climate zone:

central mountain

Estimated mean annual temperature:

-20 °C

Frozen ground depth:

35 ~

Frozen type:

dry frozen

Frozen comment:

~35

Geology

Geological setting:

the rocks of the area are granodiorites that have been cut with lamprophyre dykes and form a strongly undulating ridge and gully topography as a result of ice over riding from down-valley and up-valley glaciations and to a lesser extent, subaerial weathering; subsequent to glaciation, the terrain has been subjected to drowning and emergence from fluctuating lake levels from Lake Vanda with some sorting or resorting of surficial materials

Patterned ground:

Surface weathering or surface features:

the surface boulders are predominantly angular and unstained and show only minor abrasion around some edges

Soil

Soil parent material:

fragmented bouldery lamprophyre dyke rock with sand infilling fracture fissures; some algal accumulation near the surface

Previous disturbance:

a relatively undisturbed site apart from treking

Soil weathering stage:

6 1 (Campbell & Claridge 1975)

Soil moisture status:

xerous; the soil surface is occasionally moistened by summer snowfall;

Biological activity: