Site Information

Site number:
803
Authors:
IBC, GGC
Date recorded:
1995/01/14
Reason Sampled:
Permafrost and soil moisture investigations
Description:
Approximately 2.3km NNE of Mt Brooke on the floor of a valley; the site is on a flat surface, which has the appearance of a small terrace, on the undulating surface of the valley floor
Altitude:
2015 m
Aspect:
Nil
Slope:
0 °
Location Data
Observer GGC IBC
GPS No
Latitude Longitude DMS 76° 48.5' S 159° 54.7' E 76° 48.3' S 159° 54.1' E
Latitude Longitude DD -76.808 159.9117 -76.8050 159.9020
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 -3.7
5 -5.9
10 -6.5
15 -6.8
20 -6.8
30 -6.9
40 -7.7
50 -8.6
60 -9.7
70 -10.6
80 -11.3
90 -11.6
100 -12.5
110 -13.4
120 -14.4
130 -15.5
Estimated mean annual temperature:
-32 °C
Frozen ground depth:
0 cm
Frozen type:
dry frozen
Frozen comment:
partially ice-cemented between 55-70cm

Geology

Geological setting:
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 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:
Weakly developed non active polygons near the site
Surface weathering or surface features:
Moderately developed pebble and cobble pavement with occasional boulders; clasts non to weakly ventiform but without strong oxidation; salts beneath some surface clasts

Soil

Soil parent material:
Dominantly dolerite/volcanic till but with the fine fraction from the more erodible haloclastite
Previous disturbance:
Nil
Soil weathering stage:
6 4 (Campbell & Claridge 1975)
Soil moisture status:
Xerous; several snowfalls and a recent fall within 12 hours also considerable drift snow; most snow cover removed by wind and ablation within 24 hours; some small semi-permanent snow patches nearby,
Biological activity:
Nil observed at site
Profile Description
HorizonDepthDescription
803a -3 – 0 cm surface cobbles, pebbles and granules; subangular to subrounded and non to weakly stained,
803b 0 – 10 cm strong brown (7.5YR 5/6) gravelly pebbly sand; loose; rock particles mainly subangular and unstained, distinct boundary
803c 10 – 20 cm strong brown ( 7.5YR 5/6) gravelly pebbly sand; moderately cohesive; many diffuse salts; rock particles subangular and unstained; distinct boundary,
803d 20 – 55 cm yellowish brown to brownish yellow (10YR 5/6 - 6/6) sandy pebble and cobble gravel; firmly cohesive and salt cemented; abundant diffuse salts; rock particles subangular and unstained but some ghosts strongly disaggregated; distinct boundary,
803e 55 – 70 cm yellowish brown to strong brown (10YR 5/4 - 7.5YR 5/6) sandy gravel; very firm; ice cemented; some diffuse salts; the horizon occurs as a lens only in one side of the pit; rock particles subangular and unstained; distinct boundary,
803f 70 – 90 cm yellowish brown (10YR 5/6) pebbly to bouldery sandy gravel; weakly cohesive; some salts scattered and around stones; rock particles subangular and unstained; indistinct boundary,
803g 90 – 100 cm yellowish brown (10YR 5/6) pebbly to bouldery sandy gravel; weakly cohesive; some salts scattered around stones; rock particles subangular and unstained; distinct boundary,
803h 100 – 130 cm yellowish brown (10YR 5/6) pebbly to bouldery sandy gravel; weakly cohesive; some salts scattered around stones; rock particles subangular and unstained; distinct boundary,
803i 130 – 135 cm strong brown (7.5YR 5/6) sandy pebbly and cobbly gravel , possibly a paleosol; loose; salts diffuse and around stones; rock particles subrounded and subangular with some partly oxidised and weakly pitted

Sample Data

Physical Data
Sample nameDepth descriptionTop (cm)Base (cm)Bulk DensityDry Bulk DensityGravimetric MoistureVol. Moisture (BD=2)
803a 3-0 -3 0 1.12
803b 0-10 0 10 1.44 2.0
803c 10-20 10 20 1.39 5.51
803d 20-55 20 55 1.67 3.92
803e 55-70 55 70 1.65 7.46
803f 70-90 70 90 1.59 2.67
803g 90-100 90 100 1.6 3.28
803h 100-130 100 130 1.48 5.28
803i 130-135 130 135 1.63 2.38
Particle size distribution
Sample name< 2 mm2 - 0.5 mm0.5 - 0.25 mm0.25 - 0.1 mm0.1 - 0.05 mm0.05 - 0.02 mm0.02 - 0.002 mm< 0.002 mmFe2O3CaCO3Notes
803a 9.72
803b 79.79
803c 58.65
803d 39.42
803e 36.13
803f 29.02
803g 29.83
803h 41.2
803i 41.31
Clay Mineralogy
Sample nameMicaIHMHIV - IHMICHLVTHIVCHLSMCHL SMFE - CHLHTQTZFLDHBCALNotes
803a :
803b :
803c :
803d :
803e :
803f :
803g :
803h :
803i :

Photos

Photo record:
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