Ross Sea Region Soil Sites

Wright Valley, McMurdo Dry Valley region

Rock weathering examination

USGS 1:50,000 Antarctic Topo. Ser. Labyrinth Quadrangle

cf. Notes for DESCR below

cf. Notes for GEOLAND below

SOIL MOISTURE STATUS

Rock joint weathering debris

SOIL PARENT MATERIAL

SURFACE WEATHERING or

SURFACE FEATURES

Partial rounding of rock debris with some variable surface staining; scattered salts in material in clefts; rock surfaces are partly oxidised; some of the

weathering features may be relict

PREVIOUS DISTURBANCE

Rock weathering sample

FROZEN GROUND DEPTH(cm)

SOIL WEATHERING STAGE

South side of the Labyrinth, approximately 200m from the Wright Upper Glacier ice front; a strongly dissected relict landscape formed in dolerite with extensive

rock disintegration through columnar jointing; sample from a rock joint to give an indication of weathering since ice retreat

The Labyrinth is a fossil erosional landscape with a complex geomorphic and glacial history; there is scarcely any till in the channelised landscape but there are

accumulations of slope debris and wind drift materials; close to the glacier margin the rock jointing and other weathering features indicate that the landscape is

being exhumed; materials in cracks in the rocks may provide an indication of the weathering history

Vol. Moisture

Drill Vol

Vol. Moisture

(BD=2)

Soluble Salt

Concentration

Gravimetric

Moisture

Part. Size

0.02-0.002

Part. Size

0.05-0.02