Ross Sea Region Soil Sites
827000
827
5-Jan-1998
IBC DSS WM
Near the head of the Taylor glacier and close to Aztec Mountain in the McMurdo Dry Valley region; 2 km SE of Aztec Mt and 3.5 km SSW of Pyramid Mountain
Soil salts investigation
Not recorded
P & LScp CS
GPS
160.5820
-77.8140
77deg 48.84'S
-160deg -34.92'E
cf. Notes for DESCR below
0
Nil
1,650
cf. Notes for GEOLAND below
(Flat)
0
-5.6
10
-5.6
20
-6.8
40
-6.6
| Surface horizons moist due to recent snow fall and slight thawing, lower horizons have low |
| moisture content, ice-cemented soil with moderately high moisture content; recent snowfall |
| was 7 cm; some water in hollows on surface rocks |
-27
Xerous to subxerous, inland mountains
Dominantly dolerite, sandstone bouldery till with some granite and occasional other rock types, ice cemented;
Nil seen
Moderately developed nets, 10-15 m in diameter with 40 cm deep PG cracks, not strongly active
| SURFACE WEATHERING or |
| SURFACE FEATURES |
cf. Notes for SURFWEA below
Nil
827a 3-0cm
101
surface pebbles, granules and sand of predominantly dolerite and sandstone with some granite clasts
102
mainly subrounded and strongly stained
103
moist
104
827b 0-3 cm
201
brown to dark brown (7.5YR 5/4 - 4/4) bouldery to pebbly sandy gravel
202
moderately cohesive
203
diffuse scattered fine salt crystals
204
rock particles mainly subrounded and strongly stained with some amorphous coatings
205
indistinct boundary,
827c 3-10cm
301
strong brown (7.5YR 5/6) bouldery to pebbly sandy gravel
302
moderately cohesive
303
salts moderately abundant, mainly diffuse and patchy with some concentrated around stones
304
rock particles mainly subrounded and strongly stained with some altered
305
dry
306
indistinct boundary,
827d 10-22 cm
401
brown to strong brown (7.5YR 5/4 - 5/6) bouldery to pebbly gravel
402
weakly cohesive to loose
403
| coarser rock particles mainly subangular and weakly to moderately stained but smaller particles more strongly |
| stained |
404
dry
405
sharp boundary,
827e 22-30cm
501
yellowish brown (10YR 5/6) very hard ice-cemented frozen ground
Yes
Hard ice-cemented
22
4
Descr
| The site is located on a ridge of moraine, several hundred m above the floor of Beacon Valley on the East side; this moraine ridge appears to block or infill an |
| excavated cirque type small valley below Aztec Mountain; the moraine ridge is relatively narrow and drops towards the south; the ridge crest is flattish to |
| undulating with patterned ground; the sampling site was near the centre of a PG polygon on the ridge crest, |
Geoland
| Local rocks are dolerite and sandstone which outcrop on the ridges and in places in the basin to the south of the ridge and on the slopes of Aztec Mountain; the |
| ridge forms a distinct depositional feature and is undoubtedly an old till, probably deposited as a result of early high level ice filling Beacon Valley; the moraine |
| ridge is similar to others seen at high levels in the Taylor and Wright Valleys in that it contains erratics of non local origin, granites and other unidentified |
| crystalline rocks; if the age of moraines on lower surfaces of Beacon Valley are 'old' as prescribed by volcanic ashes (Denton & Sugden etc) then this higher |
| level moraine must be much older |
Surfwea
| Dolerite clasts are strongly stained, mainly subrounded and some partly cavernously weathered; some exfoliation and pitting are present; sandstones have very |
| strong surface oxidation, granite fragments are crumbled and some clasts well oxidised; some salts beneath surface clasts; pavement is well developed, |
| Soluble Salt |
| Concentration |
82700001
82700002
82700003
82700004
82700005
82700001
7.20
2.52
5.65
4.35
4.04
0.04
2.77
6.23
5.40
82700002
7.60
3.06
4.70
12.10
4.00
0.05
2.66
15.00
3.88
82700003
7.70
2.23
4.74
6.55
2.88
0.04
2.27
8.37
3.54
82700004
6.50
0.80
2.09
1.10
0.63
0.04
0.86
1.80
1.14
82700005
7.30
7.24
17.61
9.00
11.00
0.14
13.04
9.70
16.06
82700001
82700002
82700003
82700004
82700005
12-Dec-2005
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