523

Site number:

523

Authors:

IBC, GGC

Date recorded:

1988/01/04

Reason Sampled:

Soil weathering examination and permafrost examination

Description:

Approximately 2km east of Battleship Promontory; on the lower south slope of Alatna Valley; 20m below the crest of a minor moraine ridge on the valley side; the site is 6m from site 522 at the edge of the polygon

Altitude:

925 m

Aspect:

N

Slope:

4 °

Climate

Soil climate zone:

Coastal Mountain, xerous to subxerous

Estimated mean annual temperature:

-28 °C

Frozen ground depth:

20 cm

Frozen type:

Hard ice-cemented

Frozen comment:

20cm

Geology

Geological setting:

Alatna Valley has formed through ice recession from the Benson Glacier and ice from Staten Island Heights; the local rocks are extensive Beacon Sandstone outcrops capped with Ferrar Dolerite; the tills include granites and gneissic rocks which occur nearer the coast and indicate ice movement from the east

Patterned ground:

Weakly developed broad hummocky nets

Surface weathering or surface features:

Some dolerite weakly pitted; exfoliation and spalling are active; some cavernous weathering; boulders moderately stained and slightly rounded; a bouldery surface with some clasts upstanding; a weakly developed pavement with some ventiforms; some clasts with thick salt accumulations beneath

Soil

Soil parent material:

Sandy gravel derived from sandstone, dolerite and some granite

Previous disturbance:

Nil

Soil weathering stage:

6 3 (Campbell & Claridge 1975)

Soil moisture status:

Occasional summer snowfalls; site is dry with no adjacent snow patches

Biological activity:

Some lichen in cracks in boulders