On the SE side of Lake Bonney, immediately adjacent to and near the snout of the Hughes Glacier; a bouldery surface which forms part of a series (2nd) of moraine loops alongside the Hughes Glacier marking glacial retreat stages; the site is on a shallow, sloping, bouldery moraine loop approximately 40m from the glacier edge
Altitude:
360 m
Aspect:
NW
Slope:
10 °
Location Data
Observer
IBC
GGC
GPS
No
Latitude Longitude DMS
77° 43.7' S 162° 27.4' E
77° 43.6' S 162° 27' E
Latitude Longitude DD
-77.7283 162.4570
-77.7267 162.450
Latitude longitude precision DD
0.0008 0.0008
0.0008 0.008
Locality
Taylor Dry Valley, McMurdo Dry Valley region near Lake Bonney
Survey
USGS 1:50,000 Antarctic Topo. Ser. Lake Bonney Quadrangle
Climate
Soil climate zone:
Central Mountain
Estimated mean annual temperature:
-23
°C
Frozen ground depth:
10 > cm
Frozen type:
Frozen comment:
>10cm
Geology
Geological setting:
Alpine glaciers show clear geomorphic evidence of former advance and retreat stages with a series of small closely spaced ridges or terminal moraines over about 100m indicating the former glacier position; weathering increases with distance away from the glacier, suggesting that there may be a considerable age difference between the moraine surfaces; this surface is clearly more weathered than the surface nearer to the glacier
Patterned ground:
Nil
Surface weathering or surface features:
Some boulders are up to 2m high and have slight cavernous weathering; boulder rounding, some fracturing and exfoliation are present; there is some slight surface staining
Soil
Soil parent material:
Very bouldery granitic till with minor dolerite; there may be some reworked material
The site is dry with no snow drift or glacier runoff
Biological activity:
Nil observed
Profile Description
Horizon
Depth
Description
317a
0
–
5
cm
light yellowish brown (2.5Y 6/4) bouldery sandy gravel; loose; rock particles angular to subangular and unstained; indistinct boundary, on bouldery sandy gravel