Site Information

Site number:
909
Authors:
IBC
Date recorded:
1999/12/13
Reason Sampled:
Long Term Ecological Research (nematode experimental area) site investigation of soil properties; this site (LTER 1) was chosen for daily repeat sampling to see if there were measurable changes in soil moisture over the length of the sampling period; this sampling is the twelth at this site; this sampling was done at the conclusion of the snowfall, 4 hours after the start
Description:
LTM Datalogger plot, on the south side of Lake Hoare, approximately 100m south of Lake Hoare, on the lower slope of a ridge which forms part of an undulating ridge and gully/basin topography; the soil sampling site was on the south and upslope side of the LTM datalogger plot, which comprises a series of plastic cones covering the soil surface; the site has an even, stony gravel surface with slope increasing towards the ridge just to the south; this sampling site is designated LTER 1L and was immediately alongside LTER 1k
Altitude:
90 m
Aspect:
NNE
Slope:
5 °
Location Data
Observer IBC
GPS Yes
Latitude Longitude DMS 77° 37.99' S 162° 52.86' E
Latitude Longitude DD -77.63320 162.88100
Latitude longitude precision DD 0.00008 0.00008
Locality Near Lake Hoare, Taylor Valley, McMurdo Dry Valley region, Transantarctic Mountains
Survey Lake Bonney Quadrangle, Antarctic 1:50,000 Topographic Series, USGS 1975

Climate

Soil climate zone:
Coastal mountain
Estimated mean annual temperature:
-20 °C
Frozen ground depth:
0 Nd
Frozen type:
Nd
Frozen comment:
Nd

Geology

Geological setting:
The deposit is unweathered Ross I till, possibly derived from the Canada Glacier but almost certainly with an up-valley influence because of the presence of marble clasts from basement rocks; the tills may be fluvio-glacial owing to complex depositional ice-marginal processes as the sand % generally increases downwards while there are noticeably more coarse clasts at the surface
Patterned ground:
Moderately developed 10x20m elongate nets with 20cm deep troughs, 75cm wide
Surface weathering or surface features:
A few clasts slightly oxidised and some weak ventifaction; grey calcium carbonate coatings abundant beneath many surface clasts

Soil

Soil parent material:
Predominantly granite/gneiss/schist sandy gravel with minor amounts of dolerite, volcanic (scoria), sandstone and marble
Previous disturbance:
Site probably disturbed by foot traffic activity during biological research activities near the site
Soil weathering stage:
6 1 (Campbell & Claridge 1975)
Soil moisture status:
Xerous to subxerous; snow fall finished; approximately 1mm recorded at Camp Hoare; surface snoww free but moist
Biological activity:
Nil observed at site, nematodes present in adjacent soil; some green algae beneath marble clasts in the general area
Profile Description
HorizonDepthDescription
909a -1 – 0 cm surface cobbles, pebbles, granules and sand; moist; unstained to weakly stained; subangular to subrounded; calcium carbonate coatings beneath many clasts,
909b 0 – 2 cm light olive grey (5Y 6/2) sandy gravel; moist; loose; larger rock particles subangular with smaller particles rounded to subrounded; carbonate coatings beneath larger clasts; diffuse boundary,
909c 2 – 5 cm light olive grey (5Y 6/2) sandy gravel; loose; larger rock particles subangular with smaller particles rounded to subrounded; abundant carbonate coatings around larger and smaller clasts; diffuse boundary,
909d 5 – 15 cm light olive grey (5Y 6/2) sandy gravel; lightly frosted at 15cm; larger rock particles subangular with smaller particles rounded to subrounded; abundant carbonate coatings around larger and smaller clasts; diffuse boundary, on sandy gravel

Sample Data

Physical Data
Sample nameDepth descriptionTop (cm)Base (cm)Bulk DensityDry Bulk DensityGravimetric MoistureVol. Moisture (BD=2)
909a 1-0cm -1.0 0.0 1.59 2.05
909b 0-2cm 0.0 2.0 1.56 1.45
909c 2-5cm 2.0 5.0 1.76 0.46
909d 5-15cm 5.0 15.0 1.75 0.67
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
909a 45.0
909b 73.0
909c 76.0
909d 79.0

Photos

Photo record:
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