Long Term Ecological Research (nematode experimental area) site investigation of soil properties; this site (LTER 11) was selected for repeat sampling to measure changes in soil moisture adjacent to a retreating snow bank; this site was newly established and was examined for comparison with the other sites
Description:
South side of the newly established plot, approximately 300m south of Lake Hoare, at the western end of the experimental area and 3m upslope from the edge of the experimental plot; the stony gravel surface forms part of the somewhat hummocky, uneven lower valley side and is evenly sloping with occasional small boulders; the site is in a very slight hollow formed by adjacent low sloping ridges; this site is designated LTER 11a
Altitude:
125 m
Aspect:
WN
Slope:
12 °
Location Data
Observer
IBC
GPS
Yes
Latitude Longitude DMS
77° 38.08' S 162° 52.50' E
Latitude Longitude DD
-77.63470 162.8750
Latitude longitude precision DD
0.00008 0.0008
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;
Site temperature profile
Depth (cm)
Soil temp (°C)
Notes
1
11.9
Estimated mean annual temperature:
-20
°C
Frozen ground depth:
40 cm
Frozen type:
Hard ice-cemented
Frozen comment:
40cm
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:
Broad irregular net, 20m diameter with troughs 70cm wide and 25cm deep
Surface weathering or surface features:
A pebble cobble pavement with a few clasts weakly to moderately stained; no pitting, polish or exfoliation; moderate rounding and some ventifaction; carbonate coatings beneath many surface clasts
Soil
Soil parent material:
Sandy gravel with granite (35%) gneiss (30%) dolerite (15%) dyke rocks (10%) and minor sandstone and marble making up the coarse fraction; most coarse clasts up to 7cm (pebbles and cobbles) with occasional boulders up to 55cm
Previous disturbance:
Site probably disturbed by foot traffic activity during biological research activities near the site
Xerous to subxerous; a dry site without any adjacent snow patches
Biological activity:
Nil observed at site, nematodes present in adjacent soil; some green algae beneath marble clasts in the general area
Profile Description
Horizon
Depth
Description
892a
-2
–
0
cm
surface pebbles, cobbles, granules (60%) and sand (40%); weak to moderate staining on a few clasts; subangular to subrounded; carbonate coatings beneath many clasts; diffuse boundary,
892b
0
–
5
cm
light olive grey (5Y 6/2) pebbly to cobbly sandy gravel; loose; rock particles mainly subrounded with larger particles subangular; many carbonate coatings; diffuse boundary,
892c
5
–
12
cm
light olive grey (5Y 6/2) pebbly to cobbly gravelly sand; weakly cohesive; rock particles mainly subrounded with larger particles subangular; many carbonate coatings; diffuse boundary,
892d
12
–
25
cm
light olive grey (5Y 6/2) pebbly gravelly sand; weakly cohesive; rock particles mainly subrounded with larger particles subangular; many carbonate coatings; sharp boundary,
892e
25
–
40
cm
light olive grey (5Y 6/2) pebbly gravelly sand; moderately cohesive; moist; rock particles mainly subrounded with larger particles subangular; many carbonate coatings; sharp boundary,
892f
40
–
43
cm
pale olive to pale yellow (5Y 6/3 - 7/3) granular silty sand; very hard; ice cemented, on ice-cemented ground