Ross Sea Region Soil Sites
351000
351
11-Dec-1972
IBC, GGC
Wright Valley, McMurdo Dry Valley region, Asgard range
Soil weathering examination
USGS 1:50,000 Antarctic Topo. Ser. Labyrinth Quadrangle
B&W+CS Pro
No
160.8880
-77.5950
77deg 35.7'S
-160deg -53.3'E
| On the S side of Wright Valley in Sessrumnir Valley, approximately 2.2km NNE of Mt Freya; at the N end of a high valley shoulder surface; the site is at the edge of the valley |
| side escarpment of Wright Valley on a convex surface |
7
NNW
1,675
cf. Notes for GEOLAND below
(7o)
A dry site with no snow nearby
-25
Central Mountain
Well oxidised bouldery till from dolerite with some sandstone
Nil observed but endolithic algae present in some sandstone outcrops
Weakly developed broad nets
| SURFACE WEATHERING or |
| SURFACE FEATURES |
cf. Notes for SURFWEA below
Nil
351 5-0cm
101
surface boulders, cobbles and pebbly granular sand
102
weakly pavementic
103
rock particles subrounded to angular and strongly stained,
351a 0-2cm
201
strong brown (7.5YR 5/8) sandy gravel
202
moderately cohesive
203
moderately developed vesicular structure
204
larger rock particles subangular and strongly stained, smaller particles rounded to subrounded
205
some particles strongly altered with amorphous replacement of mineral grains distinct boundary,
351b 2-10cm
301
yellowish red (5Y 5/8) sandy to silty gravel
302
firmly cohesive
303
abundant diffuse salts with nodular aggregations
304
rock particles strongly stained
305
rounded to angular and some strongly altered
306
indistinct boundary,
351c 10-20cm
401
yellowish red (5Y 5/8) sandy to silty gravel
402
moderately cohesive
403
few distinct salt flecks
404
rock particles strongly stained subangular to rounded and some partly altered
405
some distinct strong brown oxide coatings
406
sharp boundary,
351d 20-25cm
501
strong brown (7.5YR 5/8) bouldery sandy gravel
502
hard frozen
503
rock particles angular to subrounded, moderately stained and weakly altered
Yes
a,b,c,d
Hard ice-cemented
20
5
(20cm)
Geoland
| Tills in the alpine valleys of the Asgard Range are among the oldest known in the Transantarctic Mountains and based on ash occurrences, date from the |
| Miocene; the till sequences are complex with local alpine sourced moraine being distinguished from outside sources by the presence of granite erratics; the till at |
| this site is above the granite erratic moraine appears to be of local origin with less sandstone |
Surfwea
| Dolerite boulders mostly rounded and some fracturing with some ventiform shapes; strong pitting on fine grained clasts; some dolerite cavernously weathered; |
| coarse dolerite with granular disintegration and moderate exfoliation; sandstone clasts strongly stained and very small; a moderately developed cobble/boulder |
| pavement; salts beneath surface stones |
| Soluble Salt |
| Concentration |
35100001
45.00
25.20
34.00
26.50
1.20
5.00
5.30
1.80
0.84
35100002
72.00
25.00
33.80
23.20
3.10
4.40
6.10
2.90
1.37
35100003
75.00
16.90
35.90
27.10
3.70
4.80
5.90
4.30
1.21
35100004
82.00
24.80
34.60
27.90
0.10
6.00
3.40
2.20
0.71
35100001
7.20
0.78
1.90
1.10
1.70
0.02
1.80
1.70
1.40
35100002
8.40
3.75
6.90
18.50
6.10
0.02
5.80
22.40
4.50
35100003
8.80
1.34
6.30
0.70
1.20
0.04
4.00
0.70
2.60
35100004
9.00
0.25
1.30
0.20
0.10
0.02
0.80
0.20
0.20
35100001
50
50
35100002
45
45
10
35100003
35
45
30
35100004
20
5
5
65
5
12-Dec-2005
Page 308 of 896
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