Ross Sea Region Soil Sites
798000
798
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
159.9550
-76.8017
76deg 48.1'S
-159deg -57.3'E
| Approximately 2.3km NNE of Mt Brooke on the eastern side of a valley on an undulating bench like surface about 150m above the valley floor; the sample site is on the edge |
| of a small broad knoll |
2
W
2,190
cf. Notes for GEOLAND below
| Xerous; several snowfalls but little thawing or soil moistening; small scattered pockets of |
| snow near the site |
-32
Central Mountain
Dominantly dolerite till on ice cemented ground, but with the fine fraction from the more erodible haloclastite;
nil observed at site
indistinct and weakly developed, possibly old patterned ground crack 4m away from the description site
| SURFACE WEATHERING or |
| SURFACE FEATURES |
cf. Notes for SURFWEA below
nil
798a 3-0cm
101
well developed pavement of cobbles, pebbles and few boulders
102
subrounded to rounded and subangular
103
clasts mostly unstained but polished
104
weakly ventiform
105
salts beneath some stones,
798b 0-2cm
201
light brown (7.5YR 6/4) pebbly gravelly sand
202
weakly cohesive
203
weakly developed vesicular structure
204
few salt aggregations
205
rock particles subrounded to subangular and some moderately altered
206
indistinct boundary,
798c 2-11cm
301
strong brown (7.5YR 5/6) pebbly to bouldery sandy gravel
302
moderately cohesive and partly salt cemented
303
common diffuse salts
304
rock particles subangular to subrounded with some weakly stained and moderately altered
305
distinct boundary,
798d 11-19cm
401
strong brown (7.5YR 5/6) pebbly to cobbly sandy gravel
402
moderately cohesive
403
common diffuse salts
404
rock particles subangular to subrounded and unstained but some partly altered
405
distinct boundary,
798e 19-35cm
501
light yellowish brown (10YR 6/4) bouldery sandy gravel
502
weakly cohesive
503
few fine salt flecks
504
rock particles mainly subangular and unstained
505
indistinct boundary,
798f 35-50cm
601
light yellowish brown (10YR 6/4) bouldery sandy gravel
602
weakly cohesive
603
rock particles mainly subangular and unstained, sharp boundary,
798g 50-63cm
701
light brownish gray (2.5Y 6/2) gravel
702
very hard
703
ice cemented
704
rock particles subangular and unstained,
798h 63-69cm
801
light brownish grey to light gray (2.5Y 6/2 - 7/2) ice cemented sandy gravel (drill core)
802
rock particles subangular and unstained,
798i 69-89cm
901
light brownish gray to light gray (2.5Y 6/2 - 7/2) ice cemented sandy gravel (drill core)
902
rock particles subangular and unstained,
798j 89-102cm
1001
light brownish gray to light gray (2.5Y 6/2 - 7/2) ice-cemented sandy gravel (drill core)
1002
rock particles subangular and unstained,
798k 102-119cm
1101
light brownish gray to light gray (2.5Y 6/2 - 7/2) ice- cemented gravel (drill core)
1102
rock particles subangular and unstained,
798l 119-130cm
1201
light brownish gray to light gray (2.5Y 6/2 - 7/2) ice- cemented gravel (drill core)
1202
rock particles subangular and unstained
yes
hard ice cemented
0
4
(ice-cemented at 50cm)
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 stained but most unstained but with dark |
| well polished surfaces; well developed pavement of granules, pebbles and cobbles; exfoliation or cavernous weathering is absent,,,,, |
| Soluble Salt |
| Concentration |
79800001
798a
3-0cm
-3
0
17.01
0.75
none
79800002
798b
0-2cm
0
2
1.43
63.48
2.42
none
79800003
798c
2-11cm
2
11
1.45
38.95
2.81
none
79800004
798d
11-19cm
11
19
1.49
47.69
2.98
none
79800005
798e
19-35cm
19
35
1.62
53.02
2.79
none
79800006
798f
35-50cm
35
50
1.57
45.27
2.99
none
79800007
798g
50-63cm
50
63
20.06
12.14
none
79800008
798h
63-69cm
63
69
48.64
53.80
none
79800009
798i
69-89cm
69
89
41.68
34.59
none
79800010
798j
89-102cm
89
102
47.38
23.10
none
79800011
798k
102-119cm
102
119
37.36
13.72
none
79800012
798l
119-130cm
119
130
none
79800001
17.00
0.75
79800002
63.50
2.42
79800003
39.00
2.81
79800004
47.70
2.98
79800005
53.00
2.79
79800006
45.30
2.99
79800007
20.10
12.14
79800008
48.60
53.80
79800009
41.70
34.59
79800010
47.40
23.10
79800011
37.40
13.72
79800012
49.50
24.14
79800001
79800002
79800003
79800004
79800005
79800006
79800007
79800008
79800009
79800010
79800011
79800012
79800001
79800002
79800003
79800004
79800005
79800006
79800007
79800008
79800009
79800010
79800011
79800012
12-Dec-2005
Page 775 of 896
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