Soil moisture and permafrost characterisation; undisturbed site for geochemical and soil contamination reference characterisation
Description:
North eastern end of Lake Vanda approximately 1.5km north northeast of Vanda Station; an old till surface with abundant scattered dolerite boulders; the surface is broad and moderately steeply sloping with weakly developed benches formed as a consequence of ice retreat benches
Altitude:
250 m
Aspect:
S
Slope:
21 °
Location Data
Observer
IBC
GGC
GPS
No
Latitude Longitude DMS
77° 30.8' S 161° 39.3' E
77° 30.8' S 161° 39.3' E
Latitude Longitude DD
-77.5133 161.6550
-77.5133 161.6550
Latitude longitude precision DD
0.0008 0.0008
0.0008 0.0008
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 in some places by fan detritus from intermittent low energy flows originating from gullies from the Olympus Range; the site has mainly dolerite boulders at the surface with the pavement being predominantly granodiorite; surface boulders are not thought to have originated as talus or debris falling from slopes above but have been deposited by retreating valley-filling ice
Patterned ground:
Nil
Surface weathering or surface features:
Dolerite boulders are rounded to subrounded with flattened and abraded up-wind surfaces; oxide staining on unabraded surfaces is distinct; granodiorites and granites are crumbled and have some staining; small accumulations of salts occur beneath some surface stones
Xerous; dry with no identifiable source of free water
Biological activity:
None observed
Profile Description
Horizon
Depth
Description
758a
-1 – 0 cm
surface pavement of subangular to subrounded moderately ventifacted pebbles with granules and loose sand; weak surface staining on some clasts; salts beneath some surface stones,
758b
0 – 1 cm
light yellowish brown to brownish yellow (2.5Y 7/4-10YR 6/6) pebbly gravelly sand; weakly cohesive surface crust with weakly developed vesicular structure; rock particles subangular to subrounded some with weak to moderate staining; distinct boundary,
758c
1 – 20 cm
light yellowish brown (2.5Y 6/4) cobbly silty sandy gravel; moderately to strongly cohesive; some ghosts and partly disaggregated cobble clasts; rock particles subangular to subrounded and non to weakly stained; indistinct boundary,
758d
20 – 55 cm
pale yellow (2.5Y 7/4) silty to sandy pebble and cobble gravel; moderately to strongly cohesive; some ghosts and partly disaggregated cobble clasts; abundant small to medium salt flecks; rock particles mainly sub rounded and unstained; indistinct boundary,
758e
55 – 80 cm
pale yellow (2.5Y 7/4) silty to sandy pebble and cobble gravel; moderately to strongly cohesive; few small to medium salt flecks; rock particles mainly subrounded to subangular and unstained; indistinct boundary,
758f
80 – 92 cm
light grey (2.5Y 7/2) bouldery silty to sandy till; moderately to strongly cohesive; very few fine salt flecks; rock particles mainly subangular to subrounded and unstained, on light grey bouldery till