542

Site number:

542

Authors:

IBC, GGC

Date recorded:

1988/01/13

Reason Sampled:

Soil weathering examination

Description:

On the floor of the Towle Valley, approximately 3.2km southwest of the Towle Glacier; on a bench like surface above a large snowbank; an undulating bouldery surface

Altitude:

1025 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Coastal Mountain, xerous to subxerous

Estimated mean annual temperature:

-24 °C

Frozen ground depth:

18 cm

Frozen type:

Hard ice-cemented

Frozen comment:

18cm

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; occasional small sandstone erratics indicate probable past invasion of ice into the valley from a down-valley direction; there may have been some re-working of older till deposits

Patterned ground:

Weakly developed; 25cm deep troughs; some smaller nets within larger polygons

Surface weathering or surface features:

Boulders are large with a moderately developed cobble pavement between; clasts mainly subrounded with moderate exfoliation of weathering skins; moderate to strong surface oxidation; some weak pitting; salts beneath many clasts

Soil

Soil parent material:

Locally derived drift deposits from dolerite with minor inclusion of sandstone

Previous disturbance:

Nil

Soil weathering stage:

6 4 (Campbell & Claridge 1975)

Soil moisture status:

Some surface snow cover; recent snow fall with some surface soil moistening; some boulders are moist beneath

Biological activity:

Lichens occur locally