Friday, December 26, 2008

Beacon Valley

The last stop of our field season is Beacon Valley which is an E-W striking Valley of 900 to 1200 m elevation. In the east it is bounded by the Taylor Glacier, in the west it is constraint by mountain ridges (e.g. Mount Feather) which hold back the ice flows from the Antarctic Ice Sheet. Beacon Valley has two different types of ice. In its upper part buried glacial ice is overlain by a thin layer of sublimation till and soil. Further down towards the Taylor Glacier ice cement is the common type of ground ice. Debris covered glacier originating from nive's in Mullen and Friedman Valley flowing into Beacon Valley. The picture above shows a view from the helicopter above Mount Feather into Beacon Valley; it shows the flow of debris covered glacier from side valleys into Beacon Valleys and Taylor Glacier in the east. In Beacon Valley we have two camp sites one at the Taylor Glacier and one about 6 km further up Valley. The Taylor Glacier (below) creates a 20 m ice cliff and provides us with ice for melting drinking water.

In Beacon Valley surfaces are older than in Victoria Valley and rocks which have been scoured by wind for thousands of years form ventifacts (see below).

The wind also removes the fine sand from the surface leaving behing wind scoured smaller rocks which form desert pavement as shown in the picture below. This desert pavement protects the soil before further wind erosion.

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