Ross Sea Region Soil Sites

Scott Glacier region, southern Trans-antarctic Mountains on Ackerman Ridge

Soil weathering and patterned ground examination

US Geological Survey 1:250 000, 1968, Mount Blackburn

Northern end of the La Gorce Mountains on a low moraine covered surface at the north end of Ackerman Ridge, on the east side of Scott Glacier; the surface is undulating, low

and patterned ground covered and the sample site was at the centere of a polygon

cf. Notes for GEOLAND below

Ultraxerous; snow in adjacent patterned ground cracks

SOIL MOISTURE STATUS

Ice and rubble from patterned ground

SOIL PARENT MATERIAL

Polygons up to 4m across with snow filled troughs

SURFACE WEATHERING or

SURFACE FEATURES

Angular unstained clasts with little pavement development

PREVIOUS DISTURBANCE

ice and mineral material from subsurface ice

Stagnant glacial ice

FROZEN GROUND DEPTH(cm)

SOIL WEATHERING STAGE

The ground surface is ablation till underlain by stagnant ice from the Robert Scott Glacier; the till shows a gradual progression from the Scott Glacier surface

consisting of bare ice, ice with scattered clasts, a thin continuous till cover, a thicker till cover with micro undulations and incipient patterned ground cracks,

increased till thickness and increased expression of hummocky ground and polygonal patterns. This development of patterned ground appears to be a function of

thermal expansion/contraction processes in the stagnant glacial ice and as the cracks develop, sorting of material takes place along with infilling of the cracks

with finer detritus. Surfaces such as these give strong indications of relatively recent glacial retreat. This sample was collcted from icy material below the

mineral soil to confirm that rock material in the ice was similar to that at the ground surface and therefore ablating from the ice

Vol. Moisture

Drill Vol

Vol. Moisture

(BD=2)

Soluble Salt

Concentration

Gravimetric

Moisture

Part. Size

0.02-0.002

Part. Size

0.05-0.02