Ross Sea Region Soil Sites
645000
645
5-Dec-1991
IBC, GGC, MRB
Marble Point, western McMurdo Sound
Soil weathering and reference for comparison with adjacent disturbed sites
USGS Antarctica Topographic Series 1:50,000; Marble Point, Antarctica
CS Lscp
Yes
163.6840
-77.4198
77deg 25.19'S
-163deg -41.04'E
| To the west of the disturbed old Marble Point camp area and about 30m E of a gravelly stream embankment ridge; an area apparently undisturbed by mechanical activity; on a |
| very slight rise on an otherwise level surface |
0
Nil
60
cf. Notes for GEOLAND below
30
-0.2
55
-2.5
Recent snow cover completely thawed; soil is slightly moist
-18
Coastal Antarctic
Gravelly till from mixed granodiorite, gneiss and marble
Nil at site but moss and cyanobacteria locally common
Nil
| SURFACE WEATHERING or |
| SURFACE FEATURES |
Some clasts with distinct oxide staining; a well developed pavement of mainly subangular clasts; carbonate coatings are common
No apparent mechanical disturbance but extensive surface disturbance from walking during earlier camp activity is likely
645a 3-0cm
101
surface cobbles, pebbles and granules
102
rock particles subangular, some partly stained (relict)
103
carbonate coatings on undersides of many clasts,
645b 0-5cm
201
pale olive (5Y 6/3) sandy pebble and cobble gravel
202
loose
203
rock particles angular to subangular, some weakly stained
204
sharp boundary,
645c 5-20cm
301
pale olive (5Y 6/3) gravelly sand
302
weakly cohesive
303
slightly moist
304
rock particles angular to subangular
305
diffuse boundary,
645d 20-30cm
401
pale olive (5Y 6/3) sandy gravel
402
moderately cohesive
403
rock particles subangular
404
some silt coatings
405
distinct boundary,
645e 30-55cm
501
pale olive (5Y 6/3) sandy gravel
502
firmly cohesive
503
frosted
504
rock particles subrounded to angular, some with light oxide staining
505
some silt coatings
506
sharp boundary, on hard frozen ground
Yes
Hard ice-cemented
55
1
(55cm)
Geoland
| The surface is a gently undulating till plain formed by retreat of the Wilson Piedmont Glacier; the Marble Point region is an old landscape, with deposits of |
| phillipsite, buried soils and oxidised gneiss, which have been covered by advances of the grounded Ross Ice Shelf; later ice retreat and glaciological features |
| have been controlled by changes in the stranded Wilson Piedmont Glacier; the till mantle is patchy and dominated largely by locally occurring rocks; |
| granodiorite, granite, marble, gneiss, and dolerite |
| Soluble Salt |
| Concentration |
64500001
20.00
64500002
77.00
64500003
50.00
64500004
49.00
64500005
58.00
64500001
64500002
64500003
64500004
64500005
64500001
64500002
64500003
64500004
64500005
12-Dec-2005
Page 603 of 896
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