rted from far and wide over the great expanse of the
continent.

[TEXT ILLUSTRATION]

A section of the coastal slope of the Continental Ice Sheet inland from
Winter Quarters, Adelie Land

Stillwell found these moraines a "happy hunting-ground" for the
geologist. His plane-table survey and rock collections are practical
evidence of work carried out in weather which made it seldom short of an
ordeal.

The story of the buried land to the south is in large measure revealed
in the samples brought by the ice and so conveniently dumped. Let us
swiftly review the operations leading to the deposition of this natural
museum.

As the ice of the hinterland moves forward, it plucks fragments from
the rocky floor. Secure in its grip, these are used as graving-tools
to erode its bed. Throwing its whole weight upon them it grinds and
scratches, pulverizes and grooves. The rocky basement is gradually
reduced in level, especially the softer regions. The tools are faceted,
polished and furrowed, for ever moving onwards. Finally, the rock-powder
or "rock-flour," as it is termed, and the boulders, thenceforth known
as "erratics," arrive at the terminal ice-face. Here, the melting due to
the sun's heat keeps pace with the "on-thrust" and some of the erratics
may remain stationary, or else, floating in the sea, a berg laden with
boulders breaks off and deposits its load in the depths of the ocean.
Each summer the ice-face above the rocks at Winter Quarters thawed back
a short distance and the water ran away in rivulets, milky-white on
account of the "rock-flour" in suspension. The pebbles and boulders too
heavy to be washed away remained behind to form the moraine.

The "erratics" comprised a great variety of metamorphic and igneous
rocks, and, on a more limited scale, sedimentary types. Amongst the
latter were sandstones, slates, shales and limestones.

Apart from the moraines, the rock exposed in situ was mainly a uniform
type of gneiss, crumpled and folded, showing all the signs of great
antiquity--pre-Cambrian, in the geological phrase. Relieving the grey
sheen of the gneiss were dark bands of schist which tracked about in an
irregular manner. Sporadic quartz veins here and there showed a light
tint. They were specially interesting, for they carried some less common
minerals such as beryl, tourmaline, garnet, coarse mica and ores of
iron, copper and molybdenum. The ores were present in small quantities,
but gave promise of larg