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H. T. FERRAR. 
moraine encircling them, no serious “ plucking ” of large rock-masses * can now 
be taking place. This plucking does seem to be illustrated in the ice-free cirque 
to the north of the Forts. There several blocks of Beacon Sandstone, as much 
as 20 feet in diameter, have been extracted and transported about 50 yards ; the 
sockets from which the boulders are derived are still very evident, and contain frozen 
water-ponds. 
The ice is everywhere retreating ; some few valleys are now quite bare and are 
moraine-covered. No obvious ploughing effects of ice were seen, and roches moutonnees 
are not by any means conspicuous. In Granite Harbour a few perched blocks and 
a few ice-planed rock-surfaces were observed. This harbour is fiord-like, and has 
depths of over 100 fathoms within a quarter of a mile of the shore. At Gj of the 
Northern Foothills, close to the Blue Glacier, the metamorphic limestones are 
beautifully rounded more than 1000 feet above the present ice-level and perched 
blocks are everywhere abundant. Observations at the snouts of several glaciers seem 
to show that no regular shedding of bergs is going on. Bergs from the Blue Glacier 
would contain a great quantity of rock-matter, and in former times must have 
transported an enormous quantity of debris. 
Of the many icebergs met with, few showed rock-debris on their surfaces, 
and, as piedmonts supply the vast majority of bergs, this freedom from rock- 
material is not surprising. A few bergs showed angular rock-fragments on their 
upper surfaces, and one or two had coloured dirt-bands interstratified with the 
snow-layers. Icebergs aground often capsize and bring up material from the local 
sea-floor ; this may be further transported, for through the melting of the 
berg its draught diminishes. At the same time the rock-dour, which is a very 
wide-spread deposit in the Ross Sea, is likely to be contorted by the moving 
berg. On the whole, then, we may conclude that owing to the form of the coast 
of South Victoria Land, rock-surfaces abraded or scratched by doating ice must 
there be exceptional. 
It would also seem probable that as the sea-ice diminishes during the summer, 
so are the doating piedmonts now diminishing. The numerous soundings taken by the 
‘ Discovery ’ along the edge of the Ross Piedmont, at places which at the time of the 
voyage of Ross (1841) were beneath the ice, show that the sea-door is covered with a 
stiff yellow clay (soundings 10-41), which contain tests of foraminifera, many diatom- 
frustules and a few sponge-spicules. A somewhat similar clay (soundings 176, 177, 
178) was found 10° further north near Balleny Island, also from 368 fathoms, 
(sounding 13) oft' the Nordenskiold Piedmont. In water shallower than 100 fathoms 
oceanic currents apparently remove the dne material and, as in other regions, 
deposit it beyond the littoral zone. The whole of the door of the Ross Sea 
seems to consist of rock-dour milled by the great glaciers of South Victoria 
Land. 
* Willard D. Johnson, Journal of Geology, 1904, vol. xii, p. 573. 
