Approximately 2.6km NNE of Mt Brooke on the floor of a valley and on the west side; the site is in a shallow depression formed from shallow ridge and swale topography, about 7m away from a large snow patch; the site is 50m away from soil 800
Altitude:
2000 m
Aspect:
E
Slope:
4 °
Location Data
Observer
GGC
IBC
GPS
No
Latitude Longitude DMS
76° 48.5' S 159° 54.7' E
76° 48.2' S 159° 55.2' E
Latitude Longitude DD
-76.808 159.9117
-76.8033 159.9200
Latitude longitude precision DD
0.004 0.0008
0.0008 0.0008
Locality
Coombs Hills, northern Dry Valley region and to the north of Mt Brooke
Survey
not recorded
Climate
Soil climate zone:
Central Mountain
Site temperature profile
Depth (cm)
Soil temp (°C)
Notes
1
-3
10
-2
20
-4
30
-5
40
-6
50
-7
60
-8
70
-8
80
-9
90
-10
Estimated mean annual temperature:
-32
°C
Frozen ground depth:
0 cm
Frozen type:
dry frozen
Frozen comment:
0cm
Geology
Geological setting:
Rocks of the area are dominantly 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 formed an undulating ridge and swale 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, the deposits have no dune like characteristics
Patterned ground:
Nil at site or on the immediate surface
Surface weathering or surface features:
Well developed pebble and cobble pavement with 10% boulders; doleritic clasts are subrounded and weakly ventiform with some fine pitting; salts are present beneath some surface stones
Soil
Soil parent material:
Dominantly dolerite/volcanic till but with the fine fraction from the more erodible haloclastite; till, possibly modified during deposition and or ablation by wind sorting
Xerous; several snowfalls and a recent fall within 12 hours but most ablated with little sign of soil moistening
Biological activity:
Nil observed at site
Profile Description
Horizon
Depth
Description
801a
-4
–
0
cm
surface cobbles, pebbles and granular sand; subangular to subrounded; rock particles mainly unstained but some moderately to strongly altered,
801b
0
–
3
cm
yellowish brown to brown (10YR 5/4 - 7.5YR 5/4) granular sand; loose to weakly cohesive; weakly developed vesicular structure; rock particles subrounded to subangular, mainly unstained but some strongly altered; distinct boundary,
801c
3
–
16
cm
yellowish brown (10YR 5/4) sandy pebble and cobble gravel; moderately cohesive; scattered salt aggregations; rock particles subangular to subrounded and unstained with some clasts disaggregating; the horizon is cut by a thin sand wedge; indistinct boundary,
801d
16
–
30
cm
light olive brown (2.5Y 5/4) sandy pebble and cobble gravel; weakly cohesive; many to abundant diffuse salt accumulations; rock particles subangular to subrounded and unstained; distinct boundary,
801e
30
–
50
cm
light olive brown (2.5Y 5/4) pebbly to bouldery gravel; weakly cohesive; scattered diffuse salts with accumulations on rock faces; some clasts partially disaggregated; rock particles mainly subangular; indistinct boundary,
801f
50
–
70
cm
light olive brown (2.5Y 5/4) pebbly to bouldery gravel; weakly cohesive; scattered diffuse salts with accumulations on rock faces; some clasts partially disaggregated; rock particles mainly subangular; indistinct boundary,
801g
70
–
90
cm
light olive brown (2.5Y 5/4) pebbly to bouldery gravel; weakly cohesive; scattered diffuse salts with accumulations on rock faces; some clasts partially disaggregated; rock particles mainly subangular; indistinct boundary,
801h
90
–
110
cm
light olive brown (2.5Y 5/4) pebbly to bouldery gravel; loose; few fine salt accumulations; some clasts partially disaggregating; rock particles mainly subangular and unstained; indistinct boundary,
801i
110
–
120
cm
light olive brown (2.5Y 5/4) bouldery gravel; loose; rock particles subangular and unstained