About 4km E of Lake Vashka on a high bench surface on the North side of Barwick Valley; the surface mapped as Insel Drift by Calkin (1964) is a broad undulating gently sloping till surface; the profile site was on a slight rise
Altitude:
860 m
Aspect:
S
Slope:
5 °
Location Data
Observer
IBC
GPS
No
Latitude Longitude DMS
77° 20.8' S 161° 19.3' E
Latitude Longitude DD
-77.3467 161.3220
Latitude longitude precision DD
0.0008 0.0008
Locality
Victoria Land, Trans-antarctic Mountains; in lower Barwick Valley, part of the McMurdo Sound Dry Valley system
Survey
USGS 1:250 000 1986; Ross Island and Vicinity, Antarctica
Climate
Soil climate zone:
Central mountains
Estimated mean annual temperature:
-25
°C
Frozen ground depth:
0 cm
Frozen type:
Dry frozen
Frozen comment:
Geology
Geological setting:
Insel Drift is considered to represent the deposits of a former eastward flowing ice stream from an early glaciation; however the till at this site occurs at a much lower altitude than some other deposits mapped as Insel Drift
Patterned ground:
No patterned ground
Surface weathering or surface features:
Some accumulation of small pebbles in hollows; a well developed stone pavement with some ventifacts and abraded clasts; some cavernous weathering of sandstone and also dolerite; salts abundant beneath surface stones and some oxidised patches beneath sandstone clasts; a few boulders between 60-120cm diameter
Soil
Soil parent material:
Partly weathered till derived from dolerite granite and Beacon Group sediments
Xerous to subxerous; the site is dry with moisture derived only from snow fall
Biological activity:
Nil observed
Profile Description
Horizon
Depth
Description
139a
0
–
3
cm
dark yellowish brown (10YR 4/4) granular pebbly sand; weakly to moderately cohesive with a weakly developed crust; salt patches beneath the crust and some crystalline calcium carbonate accumulations; rock particles subangular to subrounded, moderately stained partly coated with silt and clay and some moderately altered; abrupt boundary,
139b
3
–
8
cm
light olive brown (2.5Y 5/6) cobbly, pebbly, granular sand; weakly cohesive; some salts in scattered accumulations; some sandstone and granite boulder to pebble sized ghosts; rock particles mainly subangular and moderately stained with some partly altered; distinct boundary,
139c
10
–
30
cm
yellowish brown (10YR 5/8) bouldery, pebbly, silty sand; loose to weakly cohesive; abundant salt accumulations scattered throughout and adjacent to stones; larger rock particles subangular and unstained, smaller particles subrounded and moderately stained with some moderately altered; diffuse boundary,
139d
45
–
55
cm
yellowish brown (10YR 5/4) bouldery silty sand; loose; larger rock particles subangular and unstained