Ross Sea Region Soil Sites
797000
797
10-Jan-1995
IBC, GGC
Coombs Hills, northern Dry Valley region and to the north of Mt Brooke
Permafrost and soil moisture investigations
not recorded
CS Lscp & Profile
No
159.9370
-76.8033
76deg 48.2'S
-159deg -56.2'E
| Approximately 2km NNE of Mt Brooke on the eastern side of a valley on an undulating bench like surface about 100m above the valley floor; the sample site is on the crest of |
| a small knoll |
0
Nil
2,180
cf. Notes for GEOLAND below
0
-6.7
Surface,
1
-8.9
15
-7.4
50
-8.6
75
-11.0
100
-11.0
| Xerous; several snowfalls but little thawing or soil moistening; most snow removed by wind |
| and ablation; dry at site but some patches of semi-permanent snow 8m away |
-32
Central Mountain
Dominantly dolerite till but with the fine fraction from the more erodible haloclastite;
nil observed at site
nil at site
| SURFACE WEATHERING or |
| SURFACE FEATURES |
cf. Notes for SURFWEA below
nil
797a 3-0cm
101
surface cobbles, pebbles and granules forming a well developed pavement
102
some clasts strongly stained
103
patchy reddish oxide coatings in cracks
104
salts beneath some surface stones,
797b 0-1cm
201
strong brown (7.5YR 5/6) pebbly and cobbly gravelly sand
202
loose
203
rock particles subangular to subrounded and predominantly unstained
204
distinct boundary,
797c 1-8cm
301
strong brown (7.5YR 5/6) sandy pebbly cobbly and bouldery gravel
302
weakly cohesive
303
some patches of diffuse salts
304
rock particles subangular and unstained but some moderately altered
305
indistinct boundary,
797d 8-20cm
401
strong brown to yellowish red (7.5YR 5/6 - 5YR 5/6) sandy pebbly to bouldery gravel
402
weakly cohesive
403
rock particles subangular and unstained with some moderately altered with reddish oxide accumulations
404
indistinct boundary,
797e 20-40cm
501
light yellowish brown (10YR 6/4 - 2.5Y 6/4) sandy pebbly to bouldery gravel
502
moderately cohesive
503
many soft white salt flecks
504
rock particles subangular and unstained but some partly crumbled
505
indistinct boundary,
797f 40-60cm
601
light yellowish brown (10YR 6/4 - 2.5Y 6/4) sandy pebbly to bouldery gravel
602
weakly cohesive
603
few fine salt flecks
604
rock particles subangular and unstained
605
diffuse boundary,
797g 60-80cm
701
olive yellow (2.5Y 6/6) sandy pebbly to bouldery gravel
702
loose
703
rock particles subangular and angular and unstained
704
diffuse boundary,
797h 80-100cm
801
olive yellow (2.5Y 6/6) pebbly bouldery gravel
802
loose
803
rock particles angular and unstained
804
sharp boundary,
797i 100-110cm
901
light olive brown (moist 2.5Y 5/4) gravel
902
very hard and ice cemented
yes
hard ice cemented
0
4
(ice cement at 100cm)
Geoland
| Rocks of the area are dominantly dolerite/volcanic (doleritic but dark coloured, fine grained and with a somewhat vesicular form compared with usual dolerite) |
| and softer haloclastite", (earlier described as tillite); the haloclastite contains basement rocks, dolerite and sandstone clasts with sedimentary structures in places; |
| it is softer and more erodible than the dolerite; the till cover across the area is quite variable and is generally thinner towards Mt Brooke and towards the higher |
| ridges; the till mantle has an undulating surface across the landscape with a mega-ripple appearance which may relate to the manner in which the ice sheets have |
| retreated and ablated, rather than to subsequent landscape modification by wind",, |
Surfwea
| Doleritic clasts are subrounded and weakly ventiform; some deep fine pitting on larger boulders; some clasts strongly oxidised; surface polish well developed on |
| dark coloured black dolerite; well developed pavement of granules, pebbles and pebbles with about 5% surface boulders; salts beneath some surface stones,,,,, |
| Soluble Salt |
| Concentration |
79700001
797a
3-0cm
-3
0
13.52
0.69
none
79700002
797b
0-1cm
0
1
58.08
1.81
none
79700003
797c
1-8cm
1
8
1.50
54.85
2.49
none
79700004
797d
8-20cm
8
20
1.52
52.36
2.52
none
79700005
797e
20-40cm
20
40
1.64
30.72
1.36
none
79700006
797f
40-60cm
40
60
1.54
53.27
3.06
none
79700007
797g
60-80cm
60
80
1.59
43.79
0.92
none
79700008
797h
80-100cm
80
100
1.62
39.07
2.67
none
79700009
797i
100-110cm
100
110
1.66
22.26
10.65
none
79700001
13.50
0.69
79700002
58.10
1.81
79700003
54.90
2.49
79700004
52.40
2.52
79700005
30.70
1.36
79700006
53.30
3.06
79700007
43.80
0.92
79700008
39.10
2.67
79700009
22.30
10.65
79700001
79700002
79700003
79700004
79700005
79700006
79700007
79700008
79700009
79700001
79700002
79700003
79700004
79700005
79700006
79700007
79700008
79700009
12-Dec-2005
Page 774 of 896
797