Geography Reference
In-Depth Information
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a ten-foot high mound of snow, and the men struggled another five hours until they at
last reached the altar of food. Shackleton scrambled to the top of the snow mound and
dug out tins and boxes “containing luxuries of every description,” which he tossed down
to his giddy mates. They had survived. Would food ever taste so good again?
The geographical discoveries of the British Antarctic Expedition of 1907-1909 were
considerable. The vastness of the inland ice was measured by the traverses of the northern
and southern parties in their quests for the two South Poles. These lines on the map
flanked a similar line drawn by Scott's western party in 1903. Together they showed that
an ice sheet of ever rising elevation extended several hundred miles into the interior of
the continent. Because the elevations kept rising, the crest of this great sheet of ice had
to be even higher in the interior. The Western Mountains, first sighted at Cape Adare by
Ross's expedition, were now known to extend for more than one thousand miles, and
throughout that length to be the barrier between the inland ice sheet and the Ross Sea
and Ice Shelf. There could be no more question about the mountains being an archipelago
of islands. Without a doubt, they formed a continuous mountain belt which dammed the
ice of the plateau. The straits that crossed this belt were outlets for the inland ice, great
glaciers flowing inexorably downward through the mountains, tearing gigantic gashes in
the ice shelf where they met.
Shackleton's southern party also made geological discoveries that were of consid-
erable importance. When the limestone breccia from the Lower Glacier depot was ex-
amined back in Melbourne, it was found to contain fossils of a sedentary, cone-shaped
invertebrate called Archaeocyatha. These diminutive filter feeders with large pores con-
necting their inner and outer walls date from the Lower Cambrian, the oldest fossilifer-
ous horizon on the geologic timescale. Several years later, GriYth Taylor, the geologist
on Scott's Ter ra No va Expedition, was able to identify several diVerent species, with the
largest complete specimens measuring no more than a third of an inch. The breccia from
the Lower Glacier depot also yielded tiny fossils of branching, calcareous algae called Epi-
phyton, as well as sponge spicules. One of the samples of limestone from outcrop at Mount
Darwin also contained tiny fragments of Archaeocyatha. Although it was too scrappy for
specific identification, it nevertheless was the first in situ fossil of Cambrian age found on
the continent, and it remained the only one for another fifty years.
