Long Term Ecological Research (nematode experimental area) site investigation of soil properties; this site (LTER 3) was chosen for repeat sampling to measure changes in soil moisture content
Description:
North side of the LTM Datalogger plot, 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 site is at the foot of a low bouldery ridge; this sampling site is designated LTER 3c and was approximately 20m to the north of LTER 1
Altitude:
90 m
Aspect:
NE
Slope:
7 °
Location Data
Observer
IBC
GPS
Yes
Latitude Longitude DMS
77° 37.97' S 162° 52.86' E
Latitude Longitude DD
-77.63280 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
Site temperature profile
Depth (cm)
Soil temp (°C)
Notes
1
12.5
5
8.2
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:
Moderately developed 20m net with 30cm deep trough and 1m wide
Surface weathering or surface features:
A few clasts slightly oxidised and some weak ventifaction wind ripple on a few rock surfaces ; weak exfoliation on a few granite clasts; 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
Nil observed at site, nematodes present in adjacent soil; some green algae beneath marble clasts in the general area
Profile Description
Horizon
Depth
Description
885a
-1
–
0
cm
cobbly bouldery sandy gravel (50% >2mm 50% < 2mm); loose; a few clasts with weak staining; coarse particles subangular and small particles rounded; carbonate coatings beneath some clasts,
885b
0
–
2
cm
light olive grey (5Y 6/2) cobbly bouldery sandy gravel; loose; rock particles unweathered with larger rock particles subangular and smaller particles rounded; abundant carbonate coatings; diffuse boundary,
885c
2
–
10
cm
light olive grey (5Y 6/2) cobbly bouldery sandy gravel; loose; rock particles unweathered with larger rock particles subangular and smaller particles rounded; many carbonate coatings; indistinct boundary,
885d
10
–
15
cm
light olive grey (5Y 6/2) cobbly bouldery sandy gravel; loose to weakly cohesive; unweathered with larger rock particles subangular and smaller particles rounded to subrounded; many carbonate coatings; distinct boundary.
885e
15
–
30
cm
light olive grey to pale olive (5Y 6/2 - 6/3) cobbly bouldery sandy gravel; weakly cohesive and moist; unweathered with larger rock particles subangular and smaller particles rounded to subrounded; many carbonate coatings; diffuse boundary,
885f
30
–
41
cm
light olive grey to pale olive (5Y 6/2 - 6/3) sandy to silty gravel; moderately cohesive and frosted; unweathered with larger rock particles subangular and smaller particles rounded to subrounded; few carbonate coatings; sharp boundary,
885g
41
–
43
cm
light olive grey to pale olive (5Y 6/2 - 6/3) stony sandy to silty gravel; hard ice-cemented, on ice-cemented ground