Ross Sea Region Soil Sites
800000
800
11-Jan-1995
IBC, GGC
Coombs Hills, northern Dry Valley region and to the north of Mt Brooke
Permafrost and soil moisture investigations
not recorded
Lscp & CS Profile
No
159.9200
-76.7983
76deg 47.9'S
-159deg -55.2'E
| Approximately 2.6km NNE of Mt Brooke on the floor of a valley; the site is on the S edge and on the eastern side of a low valley floor ridge, which has the appearance of a |
| gravel dune; |
4
W
2,000
cf. Notes for GEOLAND below
1
12.8
10
5.5
20
3.0
30
0.0
40
-3.0
50
-6.0
75
-10.0
Xerous; several snowfalls but little thawing or soil moistening; small snow patches nearby
-32
Central Mountain
Dominantly dolerite till but with the fine fraction from the more erodible haloclastite; till, possibly modified during deposition and or ablation by wind sorting; the lower part of the profile may be a paleosol
nil observed at site
nil at site but some weakly developed patterned ground in swales between low ridges
| SURFACE WEATHERING or |
| SURFACE FEATURES |
| Strongly developed pebble and cobble pavement; doleritic clasts are subrounded and weakly ventiform; some deep fine pitting on larger boulders; surface |
| polish well developed |
nil
800a 3-0cm
101
surface pebbles and cobbles
102
well developed pavement
103
subrounded to subangular
104
most clasts dark, polished and unstained but some are moderately to strongly stained
105
salt accumulations beneath some stones,
800b 0-3cm
201
strong brown (7.5YR 5/6) sandy pebble gravel
202
loose
203
rock particles subrounded with some moderately altered with some reddish oxide coatings
204
distinct boundary,
800c 3-17cm
301
strong brown (7.5YR 5/8) pebbly gravelly sand
302
moderately to strongly cohesive
303
many salt flecks around stones
304
rock particles subrounded to subangular and unstained with some moderately altered
305
distinct boundary,
800d 17-27cm
401
yellowish red to strong brown (5YR 5/8 - 7.5YR 5/8) gravelly sand
402
firmly cohesive and strongly salt cemented
403
rock particles subangular to subrounded with some partly altered
404
distinct boundary,
800e 27-46cm
501
brownish yellow (10YR 6/8) sandy pebbly gravel
502
loose
503
moderately cohesive
504
many distinct salt flecks
505
rock particles subrounded to subangular with some weak oxide staining
506
distinct boundary,
800f 46-55cm
601
light yellowish brown (2.5Y 6/4) sandy gravel
602
firmly cohesive
603
abundant almost continuous diffuse salts
604
rock particles subangular and unstained
605
sharp boundary,
800g 55-70cm
701
brownish yellow (10YR 6/6) bouldery gravel
702
moderately cohesive
703
abundant salts
704
rock particles subangular and unstained with some granular disintegration and weak ghost formation
705
indistinct boundary,
800h 70-90cm
801
olive yellow (2.5Y 6/6) bouldery gravel
802
weakly to moderately cohesive
803
some salt accumulations
804
patches of oxide staining around some clasts
805
rock particles subrounded to subangular with some moderately stained
806
indistinct boundary,
800i 90-120
901
olive yellow (2.5Y 6/6) bouldery gravel
902
weakly cohesive
903
few patches of salt
904
rock particles subangular to subrounded with some partly stained
905
indistinct boundary, on loose bouldery gravel
yes
a,b,c,d,e,f,g,h,i
dry frozen
30
5
(30cm,)
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; although the land surface has a mega ripple, low dune-like surface, |
| Soluble Salt |
| Concentration |
80000001
800a
3-0cm
-3
0
7.65
0.59
none
80000002
800b
0-3cm
0
3
1.60
51.23
1.59
none
80000003
800c
3-17cm
3
17
1.52
55.19
4.51
none
80000004
800d
17-27cm
17
27
1.37
65.23
3.06
none
80000005
800e
27-46cm
27
46
1.55
44.23
2.57
none
80000006
800f
46-55cm
46
55
1.56
44.13
3.69
none
80000007
800g
55-70cm
55
70
1.63
21.27
2.76
none
80000008
800h
70-90cm
70
90
1.51
27.94
3.03
none
80000009
800i
90-120cm
90
120
1.62
25.80
2.95
none
80000001
7.70
0.59
80000002
51.20
1.59
80000003
55.20
4.51
80000004
65.20
3.06
80000005
44.20
2.57
80000006
44.10
3.69
80000007
21.30
2.76
80000008
27.90
3.03
80000009
25.80
2.95
80000001
80000002
80000003
80000004
80000005
80000006
80000007
80000008
80000009
80000001
80000002
80000003
80000004
80000005
80000006
80000007
80000008
80000009
12-Dec-2005
Page 777 of 896
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