774

Site number:

774

Authors:

IBC,GGC,MRB,DIC

Date recorded:

1994/01/20

Reason Sampled:

Permafrost and soil moisture investigations for comparison with soils from moist coastal regions

Description:

Near the mouth of the valley, in a broad shallow depression, about 20m above the floor of the depression a low moraine ridge; approxinmately 1.7km northeast of West Beacon and 2km north northwest of East Beacon; the surface is convex with gentle undulations and a few large boulders

Altitude:

1700 m

Aspect:

E

Slope:

3 °

Climate

Soil climate zone:

Central Mountain

Estimated mean annual temperature:

-30 °C

Frozen ground depth:

59 cm

Frozen type:

hard ice-cemented

Frozen comment:

59

Geology

Geological setting:

Local outcropping rocks are Ferrar Dolerite and Beacon Sandstone; the till at this site is similar to the till forming the ridge at the mouth of the valley in that it contains some granite and granodiorite clasts indicating a till source from outside the valley; the floor of the depression may mark the up valley limit of the ice advance that brought extensive granodioritic till at the valley mouth

Patterned ground:

No polygon cracks within 25m; some old infilled cracks

Surface weathering or surface features:

Dark brown stained, polished and pitted dolerite rocks forming a cobble and boulder pavement; few granitic rocks present but these are strongly altered; sandstone clasts are exfoliated; some weakly ventifacted clasts

Soil

Soil parent material:

Bouldery to cobbly gravelly sand; some finer material in the upper part of the profile

Previous disturbance:

Nil

Soil weathering stage:

6 4/5 (Campbell & Claridge 1975)

Soil moisture status:

Xerous; some snow falls in winter and summer months but most is lost through ablation or by blowing away; a dry site with no snow pockets nearby

Biological activity:

Only endolithic algae observed below the surface of sandstone boulders or outcrops