Ross Sea Region Soil Sites

South side of Upper Taylor Glacier between West Beacon and New Mountain; a small relict hanging valley 2 km east of Arena Valley

Soil salts investigation

cf. Notes for DESCR below

cf. Notes for GEOLAND below

Recent snowfall and some moisture in surface horizons which froze; lower horizons dry;

snow patches are scarce and no liquid water observed

SOIL MOISTURE STATUS

Xerous to subxerous, inland mountains

Dominantly dolerite and sandstone bouldery till with some granite; non ice-cemented

SOIL PARENT MATERIAL

SURFACE WEATHERING or

SURFACE FEATURES

cf. Notes for SURFWEA below

PREVIOUS DISTURBANCE

The area was disturbed in 1987 and a camp site, a former pit site and helicopter skid marks were still visible

surface pebbles, granules and sand forming a well developed pavement surface

clasts subrounded, strongly stained and ventiform,

brown (7.5YR 5/4) gravelly coarse sand

moderately cohesive and weakly vesicular

rock particles rounded to subrounded, strongly stained and some altered

some reddish amorphous coatings in fissures

sharp wavy boundary,

strong brown (7.5YR 5/6) pebbly gravelly coarse sand

loose to weakly cohesive

diffuse salts but patchy with thick encrustations beneath some penetrating surface stones

rock particles subrounded, strongly stained and some altered with amorphous coatings in fissures

strong brown (7.5YR 5/8) cobbly gravelly sand

weakly cohesive to loose

some scattered salt accumulations but salts also diffuse

some cobble sized ghosts, completely disaggregated

rock particles mainly subrounded to sub angular and moderately stained

yellowish brown (10YR 5/8) gravelly sand

rock particles mainly angular and weakly stained

brownish yellow to yellowish brown (10YR 6/6 - 5/6) gravelly sand (paleosol?)

salt cemented with profuse crystalline precipitations

rock particles mainly subrounded and moderately stained

strong brown (7.5YR 5/6) gravelly sand

weakly to moderately cohesive

rock particles subrounded to subangular with some stained and oxidised pebbles

indistinct boundary,

yellowish red (10YR 6/6 - 6/8) sandy gravel with some brownish yellow (10YR 5/6) sandy patches

rock particles mainly subangular and weakly to moderately stained

brownish yellow (10YR 6/6) silty sand

weakly cohesive to loose

weak crumb like microfabric

rock particles rounded to subrounded and moderately stained

yellowish red (7.5YR 6/6 - 6/8) stony sandy gravel (weak paleosol?)

weakly to moderately cohesive

few scattered fine salts

rock particles subangular and weakly stained

indistinct boundary,

light yellowish brown to brownish yellow (10YR 6/4 - 6/6) gravelly sand

patchy textural differences possibly from proglacial sorting

rock particles subangular to sub rounded and weakly stained

indistinct boundary,

very pale brown (10YR 7/4) gravelly sand

loose but some weakly cohesive patches

pebbles and cobbles mainly angular and unstained

very pale brown to light yellowish brown (10YR 7/4/-/6/4) silty to sandy gravel

rock particles mainly angular and unstained

FROZEN GROUND DEPTH(cm)

SOIL WEATHERING STAGE

The site is located near the mouth of a small hanging valley on a flattish surface, about 100 m up valley from the escarpment formed by the break in slope with

the side of the upper Taylor Valley; the site is a stable glacial retreat surface which gently rises up valley to the south and is notable for the occurrence of some

very large (circa 6 m) granite boulders; a somewhat windy site on occasions

Local outcropping rocks are Ferrar Dolerite and Beacon Sandstone; the valley entrance, floor and part of the valley sides, however, have till deposits of

non-local origin which include the now familiar granite erratic tills deposited as an up-valley re-advance from the Taylor Glacier into what may have been old

empty hanging cirque valleys; multiple re- invasions of ice into this valley are indicated by paleosols in the till deposits; the proportion of granite erratic in these

valley floor tills appears to diminish up valley, which again suggests multiple ice event deposition; the possibility of ice invasion with minimal till deposition

exists as some sandstone boulders are pale coloured and weakly oxidised, contrasting with surrounding strongly oxidised sandstone clasts

There is a well developed desert pavement of pebbles and cobbles with some flattish boulders, all showing some ventifaction; the very large granite boulders are

rounded and have moderately oxidised surfaces but appear to sit on the surface suggesting that these may have been a later addition; some smaller granite

boulders however are strongly disaggregated; pitting on dolerite is well developed as are oxidation and polish; thick encrusting salt deposits occur beneath many

surface clasts

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