Ross Sea Region Soil Sites
313000
313
19-Nov-1972
IBC, GGC
Taylor Dry Valley, McMurdo Dry Valley region near Lake Bonney
Soil weathering examination
USGS 1:50,000 Antarctic Topo. Ser. Lake Bonney Quadrangle
CS+B&W Lsc & Pro
No
162.0500
-77.7000
77deg 42.0'S
-162deg -3.0'E
cf. Notes for DESCR below
5
SE
150
cf. Notes for GEOLAND below
(5o)
0
0.0
0
-7.0
3
-1.0
10
-5.0
40
-10.0
Surface dry with damp patches; dampness may be influenced by soil salinity
-23
Central Mountain
Sandy to silty gravel, moist patch
Nil observed
Nil
SURFACE WEATHERING or |
SURFACE FEATURES |
Scattered upstanding dolerite boulders, rounded to subrounded, some partly fragmented, non to weakly stained; weakly to moderately developed pebble |
pavement; granite boulders exfoliating and crumbling; a weakly developed cobble pavement |
Nil
313 3-0cm
101
surface pebbles and cobbles
102
subrounded
103
non to weakly stained
104
ground surface and surface of stones is moist,
313a 0-12cm
201
light olive brown (2.5Y 4/4 moist) sandy gravel
202
weakly cohesive
203
rock particles angular to subangular and unstained
204
distinct boundary,
313b 12-30cm
301
light yellowish brown (2.5Y 6/4) sandy to silty gravel
302
loose
303
rock particles rounded to subrounded and unstained
304
distinct boundary,
313c 30-38cm
401
light olive brown (2.5Y 5/6) sandy fine gravel
402
weakly cohesive
403
frosted
404
rock particles subrounded and unstained
405
distinct boundary,
313d 38-55cm
501
light olive brown (2.5Y 5/6) sandy gravel
502
loose
503
sharp boundary, on frozen ground
Yes
a,b
Hard ice-cemented
40
2
(40cm)
Descr
On the north side of Lake Bonney on the lower valley surface between Matterhorn and La Croix Glaciers on a broad sloping gravelly surface with patches of |
damp ground surface; approximately .5km from the NE end of Lake Bonney; site is 1m from site 312 where the surface soil is damp |
Geoland
The lower valley sides are covered with tills derived from local granite and dolerite; The valley has a complex history of glacial advances and retreats and |
probably also fluctuating lake levels; patches of ground with apparently moist soil surfaces suggest the possibility of subsurface moisture flow but there is little |
evidence for this; the moist patches may relate to salinity differences within the regolith and hygroscopic movement of moisture |
Soluble Salt |
Concentration |
31300001
73.00
40.70
23.60
12.90
5.70
4.50
8.30
4.10
0.13
31300002
95.00
9.70
30.60
39.60
9.10
4.60
5.40
0.80
0.15
31300001
8.40
2.50
17.40
1.30
27.30
48.30
4.40
0.21
31300002
8.90
3.50
6.30
1.40
4.30
10.30
0.64
0.06
31300001
35
10
10
45
31300002
40
35
25
12-Dec-2005
Page 270 of 896
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