Soil moisture and permafrost characterisation; undisturbed site for geochemical and soil contamination reference characterisation
Description:
North eastern end of Lake Vanda approximately 1.1km north northeast of Vanda Station just above the benchmark marking the uppermost recognised old lake bench level; the surface is an even, broadly sloping surface on the western side of a fan which merges with the lake benches
Altitude:
150 m
Aspect:
S
Slope:
9 °
Location Data
Observer
IBC
GGC
GPS
No
Latitude Longitude DMS
77° 31.1' S 161° 39.5' E
77° 31.1' S 161° 39.5' E
Latitude Longitude DD
-77.5183 161.658
-77.5183 161.658
Latitude longitude precision DD
0.0008 0.004
0.0008 0.004
Locality
Wright Valley, on the northern side opposite Vanda Station
Survey
not recorded
Climate
Soil climate zone:
Central Mountain
Estimated mean annual temperature:
-24
°C
Frozen ground depth:
0 cm
Frozen type:
Dry frozen, loose
Frozen comment:
Geology
Geological setting:
The rocks of the valley side are granodiorites cut by lamprophyre dykes and intruded with dolerite; old compact silty till, including Peleus or Jason Till, and younger up-valley coarser tills with a variety of basement rock types included, mantle the valley sides; these deposits and the surface features have been weakly modified by fan detritus from intermittent low energy flows originating from gullies from the Olympus Range; slopes below the site have been modified by wave action during times of higher lake levels; the fan sediments are thin and generally form a thin veneer, weakly stratified, poorly sorted and generally only form a thin (< 50cm) deposit
Patterned ground:
Nil at site but some broadly spaced sand filled cracks nearby
Surface weathering or surface features:
A pavement of mainly angular to subangular pebbles, some very weakly ventiform and with negligible surface staining; no surface salts visible
Soil
Soil parent material:
Stratified weakly to moderately sorted fan sediments over old sandy silty till
Xerous; dry with no identifiable source of free water
Biological activity:
None observed
Profile Description
Horizon
Depth
Description
757c
light grey (10YR 7/2) cobbly gravelly sand; moderately cohesive and moderately developed vesicular structure; rock particles subangular to subrounded and unstained; sharp boundary
757a
-2
–
0
cm
surface pavement of small pebbles and granules; mostly subangular and unstained,
757b
0
–
14
cm
greyish brown (10YR 5/2) pebbly to granular gravelly sand; weakly cohesive; rock particles subangular and unstained; distinct boundary,
757d
25
–
45
cm
light brownish grey (10YR 6/2) pebbly granular sand; weakly cohesive; weak sedimentary layering; rock particles subangular and unstained; sharp boundary,
757e
45
–
74
cm
pale yellow to light yellowish brown (2.5Y 7/4-6/4) sandy pebble and cobble gravel; moderately to strongly cohesive; rock particles subangular to rounded, some with weak staining; sharp boundary;
757f
74
–
90
cm
light brownish grey (2.5Y 6/2) bouldery silty to sandy gravel; moderately cohesive; rock particles are mainly subangular to subrounded and unstained but the upper part of the horizon has some partly oxidised subrounded clasts (cont.); rock particles..clasts with small strong brown (7.5YR 5/8) oxidised fine earth patches and is probably a thin paleosol, on light brownish grey till