832

Site number:

832

Authors:

IBC DSS WM

Date recorded:

1998/01/09

Reason Sampled:

Soil water loss after snowfall, sampled 18 and 36 hours after initial sampling for soil 830

Description:

The site is located near the mouth of a small hanging valley on a flattish surface, about 100 m up valley from the escarpment formed by the break in slope with the side of the upper Taylor Valley; the site is a stable glacial retreat surface which gently rises up valley to the south and is notable for the occurrence of some very large (circa 6 m) granite boulders; a somewhat windy site on occasions, the sample site was approximately 20 m N of the camp site

Altitude:

1500 m

Aspect:

NE

Slope:

20 °

Climate

Soil climate zone:

Xerous to subxerous, inland mountains

Estimated mean annual temperature:

-30 °C

Frozen ground depth:

10 ~ cm

Frozen type:

Dry frozen

Frozen comment:

~10cm

Geology

Geological setting:

Local outcropping rocks are Ferrar Dolerite and Beacon Sandstone; the valley entrance, floor and part of the valley sides, however, have till deposits of non-local origin which include the now familiar granite erratic tills deposited as an up-valley re-advance from the Taylor Glacier into what may have been old empty hanging cirque valleys; multiple re- invasions of ice into this valley are indicated by paleosols in the till deposits; the proportion of granite erratic in these valley floor tills appears to diminish up valley, which again suggests multiple ice event deposition; the possibility of ice invasion with minimal till deposition exists as some sandstone boulders are pale coloured and weakly oxidised, contrasting with surrounding strongly oxidised sandstone clasts

Patterned ground:

Nil at site

Surface weathering or surface features:

There is a well developed desert pavement of pebbles and cobbles with some flattish boulders, all showing some ventifaction; the very large granite boulders are rounded and have moderately oxidised surfaces but appear to sit on the surface suggesting that these may have been a later addition; some smaller granite boulders however are strongly disaggregated; pitting on dolerite is well developed as are oxidation and polish; thick encrusting salt deposits occur beneath many surface clasts

Soil

Soil parent material:

Dominantly dolerite and sandstone bouldery till with some granite; non ice-cemented

Previous disturbance:

The area was disturbed in 1987 and a camp site, a former pit site and helicopter skid marks were still visible

Soil weathering stage:

6 4 (Campbell & Claridge 1975)

Soil moisture status:

Recent snowfall and some moisture in surface horizons which froze; lower horizons dry; snow patches are scarce and no liquid water observed; samples a-c were collected 18 hours after the initial sampling after some drying had occurred and samples d-f 24 hours later

Biological activity:

Nil observed