Long Term Ecological Research (nematode experimental area) site investigation of soil properties; this site (LTER 10) was chosen for daily repeat sampling to see if there were measurable changes in soil moisture over the length of the sampling period
Description:
Elevational transect A Plot, on the south side of Lake Hoare, approximately 100m south of Lake Hoare, and 150m east of the LTM Datalogger Plot; on the upper part of a shallow sloping gravelly basin surface; the sampling site was on the south and upslope side of the Elevational Transect A Plot; the area comprises shallow northward sloping, somewhat bouldery ridges separated by depressions with fine gravelly surfaces; this sampling site is designated LTER 10a
Altitude:
85 m
Aspect:
NW
Slope:
7 °
Location Data
Observer
IBC
GPS
Yes
Latitude Longitude DMS
77° 37.96' S 162° 53.22' E
Latitude Longitude DD
-77.63270 162.88700
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
Site temperature profile
Depth (cm)
Soil temp (°C)
Notes
1
13
5
7.5
12
1.6
20
-0.5
30
-0.5
40
-3
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; some weak sedimentary bedding
Patterned ground:
Moderately developed 20m irregular nets with 20-35cm deep troughs, 75cm wide
Surface weathering or surface features:
Nil surface staining, pitting and exfoliation; some clasts slightly oxidised, probably from pre-weathering; weak ventiforms and a well developed pebble pavement; moderate rounding; many carbonate coatings on undersides of surface clasts
Soil
Soil parent material:
Sandy pebble gravel to sand; predominantly granite (40%) gneiss, dyke rock, dolerite and volcanic (scoria)
Previous disturbance:
Site probably disturbed by foot traffic activity during biological research activities near the site
Xerous to subxerous; a dry site with no adjacent snow banks
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
868a
-1
–
0
cm
surface pebbles, granules (43%) and sand (57%) with occasional cobbles; unstained; subangular to subrounded; calcium carbonate coatings beneath many clasts,
868b
0
–
2
cm
light olive grey (5Y 6/2) gravelly sand (36% >2mm 64% <2mm); loose; rock particles subangular to rounded; carbonate coatings around larger clasts; diffuse boundary,
868c
2
–
10
cm
light olive grey (5Y 6/2) sand with some pebbles; loose; larger rock particles subangular to subrounded and smaller particles subrounded to rounded; many carbonate coatings around larger clasts; sharp boundary,
868d
10
–
18
cm
light olive grey (5Y 6/2) sand with pebbles and occasional cobbles; moist and cohesive; rock particles mainly subrounded to rounded; many carbonate coatings; sharp boundary,
868e
18
–
26
cm
light olive grey (5Y 6/2 ) sand with some pebbles; firmly cohesive and frosted; rock particles rounded to subrounded; many carbonate coatings; around larger and smaller clasts; diffuse boundary,
868f
26
–
40
cm
light olive grey (5Y 6/2) sand with occasional pebbles; moderately cohesive; rock particles rounded to subrounded; few carbonate coatings; sharp boundary,
868g
40
–
42
cm
light olive grey to pale olive (5Y 6/2) gravelly sand; very hard; ice-cemented, on; hard ice-cemented ground