536

Site number:

536

Authors:

IBC, GGC

Date recorded:

1988/01/10

Reason Sampled:

Soil biological examination

Description:

At the Northeastern end of the Towle Valley; on a low moraine ridge about 150m from the Towle Glacier; adjacent to a patterned ground crack; sample a from alongside a boulder; ample b from a salty spot 75cm away

Altitude:

900 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Coastal Mountain, xerous to subxerous

Estimated mean annual temperature:

-24 °C

Frozen ground depth:

0 cm

Frozen type:

Hard ice-cemented

Frozen comment:

Geology

Geological setting:

Towle Valley is formed almost entirely in dolerite; the tills, moraines and soils indicate a northeasterly retreat of the Towle Glacier from the valley; land surfaces on the lower valley floor appear not to be very old; the tills may be rather old but may have been over-ridden by repeated incursions of the Towle Glacier into the valley; a few granite clasts are present; there may have been some re-working of older tills

Patterned ground:

Moderately developed net; 40cm deep crack with active boulder infilling

Surface weathering or surface features:

Extensive bouldery surfaces with predominantly angular clasts; some boulders showing extensive spalling and fragmentation and some crumbling; patchy staining may be relict; salts encrust undersides of many clasts,

Soil

Soil parent material:

Bouldery dolerite till, possibly pre-weathered

Previous disturbance:

Nil

Soil weathering stage:

6 1 (Campbell & Claridge 1975)

Soil moisture status:

Recent snow cover shows evidence of widespread thaw; the soils are moist in places and appear to be periodically wet; water occurs in some small pools; some snow in the patterned ground crack

Biological activity:

Yellow lichens occur in patches; cyanobacteria in pools