Site Information

Site number:
440
Authors:
IBC, GGC
Date recorded:
1978/11/19
Reason Sampled:
Soil weathering examination
Description:
The Darwin Mountains, just to the south of the Midnight Plateau; the site is near site 338 but from beneath a consolidated snowpack; the snow forms a continuous cover merging into the Midnight Plateau ice field; the soil beneath 60cm of hard snow was examined to compare soil weathering from beneath the snow cover with that at site 338 beyond the snowpack
Altitude:
1650 m
Aspect:
Nil
Slope:
0 °
Location Data
Observer IBC GGC
GPS No
Latitude Longitude DMS 79° 56.9' S 156° 16.4' E 79° 57' S 156° 16' E
Latitude Longitude DD -79.9483 156.2730 -79.950 156.267
Latitude longitude precision DD 0.0008 0.0008 0.008 0.008
Locality Hatherton Glacier, Darwin Mountains, Transantarctic Mountains
Survey United States Geological Survey 1966; 1:250,000 Carlyon Glacier, Antarctica

Climate

Soil climate zone:
Central Mountain
Estimated mean annual temperature:
-35 °C
Frozen ground depth:
0 cm
Frozen type:
Hard ice-cemented
Frozen comment:
0cm

Geology

Geological setting:
Rock outcrops on the area are Ferrar Dolerite; the ground surfaces have been exposed following retreat of ice from the Midnight Plateau; close to the ice edge, the soils appear less weathered but distinct successional surfaces marking ice retreat are not present; with increasing distance away from the ice front, soil weathering increases; the weathering is probably relict and unrelated to the present ice cover
Patterned ground:
Nil
Surface weathering or surface features:
Not observed

Soil

Soil parent material:
Frozen till beneath consolidated snowpack
Previous disturbance:
Nil
Soil weathering stage:
6 4 (Campbell & Claridge 1975)
Soil moisture status:
Permanent snow cover
Biological activity:
Nil observed
Profile Description
HorizonDepthDescription
440a 0 – 4 cm yellowish brown (10YR 5/6 moist) sandy gravel; hard frozen; rock particles subangular to subrounded, unstained but easily disaggregated; NB: the rock particles in the sample have a very dark, almost blackish look and crush easily - the unusual dark colour is suggestive of anoxic weathering conditions

Sample Data

Physical Data
Sample nameDepth descriptionTop (cm)Base (cm)Bulk DensityDry Bulk DensityGravimetric MoistureVol. Moisture (BD=2)
440a 0-4cm 0.0 4.0 No
Particle size distribution
Sample name< 2 mm2 - 0.5 mm0.5 - 0.25 mm0.25 - 0.1 mm0.1 - 0.05 mm0.05 - 0.02 mm0.02 - 0.002 mm< 0.002 mmFe2O3CaCO3Notes
440a
Clay Mineralogy
Sample nameMicaIHMHIV - IHMICHLVTHIVCHLSMCHL SMFE - CHLHTQTZFLDHBCALNotes
440a :

Photos

Photo record:
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