531

Site number:

531

Authors:

IBC, GGC

Date recorded:

1988/01/06

Reason Sampled:

Soil weathering examination

Description:

Central Alatna Valley, approximately 9km NNE of Battleship Promontory; 500m from the southern edge of the stagnant Staten Island Heights glacier; on an undulating moraine surface; the site is a sand accumulation patch behind a boulder and in a patterned ground crack

Altitude:

950 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Coastal Mountain, xerous to subxerous

Estimated mean annual temperature:

-25 °C

Frozen ground depth:

0 cm

Frozen type:

Frozen comment:

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; granite outliers are also present; the presence of pink Irizar Granite indicates earlier up-valley ice movement; many of the soils are very sandy below the bouldery surface; the sand may in part originate from local erosion and become incorporated into the soil through cryic processes

Patterned ground:

Extensive and well developed broad nets with active movement

Surface weathering or surface features:

Loose sandy surface; clasts in the patterned ground crack are subangular and weakly stained

Soil

Soil parent material:

Wind-blown sand

Previous disturbance:

Nil

Soil weathering stage:

6 1 (Campbell & Claridge 1975)

Soil moisture status:

Periodic summer snow falls; snow in patterned ground cracks but little visible soil moistening

Biological activity:

Nil observed