Ross Sea Region Soil Sites
415000
415
11-Dec-1977
IBC, GGC
Wright Valley, Bull Pass
Soil weathering examination
USGS, Antarctica 1:50,000 Topo. Ser. 1977 Victoria Upper Lake Antarctica
CS Lscp & Pro
No
161.8580
-77.4933
77deg 29.6'S
-161deg -51.5'E
| On the east side of Bull Pass near the southern end; below a moraine tongue near the foot of the slope below Sandy Glacier; approximately 2.8km SSW of Mt Orestes; a long |
| sloping slightly concave and subdued surface |
15
SW
620
cf. Notes for GEOLAND below
(15o)
A recent snowfall resulted in surface soil moistening followed by rapid drying
-24
Coastal Mountain
Granite, sandstone and dolerite sandy gravel till with accessions of a few other dyke rocks
Nil observed
Nil
| SURFACE WEATHERING or |
| SURFACE FEATURES |
| Occasional large boulders showing advanced disintegration; granite clasts oxidised on upper surfaces and many disaggregated; a moderately developed |
| cobble, pebble to granular sand pavement; moderate surface abrasion and ventiform development |
Nil
415a 2-0cm
101
surface pebbles cobbles and granular sand
102
rock particles mainly subangular and non to weakly stained,
415b 0-3cm
201
light yellowish brown to pale yellow (2.5Y 6/4 - 7/4) sandy gravel
202
moderately cohesive
203
strongly developed vesicular structure
204
some clasts strongly disaggregating
205
larger rock particles angular but small particles rounded and moderately stained
206
distinct boundary,
415c 3-17cm
301
light olive brown (2.5Y 5/4) sandy gravel
302
moderately cohesive
303
some granite clasts strongly disaggregating
304
rock particles mainly angular and unstained but small particles rounded
305
indistinct boundary,
415d 17-38cm
401
light olive brown (2.5Y 5/4) sandy gravel
402
cohesive
403
abundant medium salt flecks diffused through the horizon and encrustations around stones
404
rock particles angular and unstained but some granite clasts disaggregating
405
indistinct boundary,
415e 38-52cm
501
light olive brown (2.5Y 5/4) bouldery sandy gravel with a few brownish patches around rocks
502
moderately cohesive
503
few fine salt flecks
504
some granite clasts disaggregating
505
rock particles angular and unstained
506
indistinct boundary,
415f 52-96cm
601
pale olive (5Y 6/3) bouldery sandy to silty gravel
602
loose
603
rock particles angular and unstained on bouldery sandy gravel
Yes
Dry frozen
96
3
(>96cm)
Geoland
| Bull Pass area is complex in respect of its glaciological history; the valley side tills give an indication of the glacial and weathering sequences; south of Mt |
| Orestes, a moraine lobe on the valley side appears to have originated from the valley side cirque occupied by Sandy Glacier; this valley side till is older and may |
| have come from ice entering Bull Pass from Wright Valley, judged by a range of erratics |
| Soluble Salt |
| Concentration |
41500001
47.00
41500002
87.00
41500003
77.00
41500004
73.00
41500005
84.00
41500006
66.00
41500007
80.00
41500001
41500002
41500003
41500004
41500005
41500006
41500007
41500001
41500002
41500003
41500004
41500005
41500006
41500007
12-Dec-2005
Page 372 of 896
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