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 (4th) of moraine loops marking glacial retreat stages; the site is in a hollow between the 3rd and 4th moraine loops which are marked by a ridge of boulders approximately 55m 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' S 162° 34' E
Latitude Longitude DD
-77.7283 162.4570
-77.717 162.567
Latitude longitude precision DD
0.0008 0.0008
0.008 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:
30 > cm
Frozen type:
Frozen comment:
>30cm
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 4th surface on a patch of finer till is clearly more weathered than the surfaces nearer to the glacier
Patterned ground:
Nil
Surface weathering or surface features:
A well developed pebble pavement with distinct surface oxidation
Soil
Soil parent material:
Fine gravelly 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
319a
0 – 5 cm
yellowish brown to olive brown (10YR 5/6 - 2.5Y 5/6) sandy gravel; a few fine salt flecks; rock particles subangular to subrounded and weakly stained indistinct boundary, on sandy gravel