Geography Reference
In-Depth Information
175
At the summit Blackburn also found faceted pebbles and striations on the bedrock
indicating that all of Supporting Party Mountain had been overridden at some time in
the past by glacier ice standing at least one thousand feet higher than the levels around
the base of the peak today.
Stratus clouds closed in while the men were on the summit, creating beautiful
shadow patterns on the snowfields below, but permitting only fleeting views of the
mountains. For a time the clouds rolled back revealing Leverett Glacier banked along the
Watson Escarpment, its headreaches seeming to arise somewhere far to the east beneath
the cliV face, but the distant parts were obscured by a shoulder of land. With no appar-
ent access to the plateau in that direction, and with most of the face of Watson Escarp-
ment mantled with icefalls, Blackburn chose instead to venture up Scott Glacier, where
the image of bare rock faces and tier upon tier of snow-clad peaks had slowly taken shape
as the party approached the range. First the mountains had been a thin band of blue-gray
at the horizon, then the main massifs took form between the outlet glaciers. Eventually
the ridges had begun to reach out and down from the blocky summits. And with the
sun directly out of the north, demarcations of light and dark had hinted of exposures of
bedrock through the ice. Close in Scott Glacier could be seen to issue from a deep cor-
ridor lined by mountains, gabled and domed, utterly unknown, a field geologist's dream
(Fig. 6.1).
The next day, November 28, the party headed west-southwest toward Durham Point
at the gateway to Scott Glacier (Fig. 6.2). Where Leverett Glacier enters the Ross Ice
Shelf, it is thrown into broad rolls of rippled blue ice. After crossing its mouth, the party
collected some more schist at a small nunatak along the route, and then pitched camp
about a half mile east of Durham Point (Fig. 6.3). After dinner Blackburn went out to the
cliV face just south of camp. There the rock was a gray granite cut through with many
coarsely crystalline mineral veins, called pegmatites. The potassium-bearing feldspar,
microcline, gave the pegmatites a pinkish blush.
The following day temperatures were a mild 16° F, but a twenty-knot wind from the
east aZicted the party. A swift run down an ice slope brought the men to the rock, where
they built a cairn, marking their passage and naming the feature Durham Point, after
Paine's hometown of Durham, New Hampshire. Steering wide to avoid the steep, pres-
sured ice at the cape, the party rounded the point and began the ascent of Scott Glacier.
Strato-cumulus clouds gathered and shifted over the nearground, and cumulus capped
the distant peaks, with a heavy ground drift swishing past the party's knees. At clefts in
the rocks to the east the wind poured through with amplified vigor.
That evening the party camped in the shadow of Mount Hamilton (see Fig. 6.3),
close enough to the face to receive some protection from the continuing easterly wind.
Paine recorded, “To-night had hamburger hash, milk, sherry + ice cream. A strange meal
in a strange place and Thanksgiving too.” The rocks at the base of the mountain again
were gray granite cut by pink pegmatitic dikes, but here also was some of the black schist
like that at Supporting Party Mountain. The granite clearly crosscut it, demonstrating
that it was the younger of the two rocks, though the absolute age of either of the rocks
was still beyond the capabilities of the technology of the day. From there on to the south
Blackburn would take no samples, resuming only when the party was homeward bound
Figure 6.1. (overleaf) Tier
after tier of ragged peaks
line the margins of Scott
Glacier, furrowing through
the Queen Maud Moun-
tains and skirting the left
(east) side of Taylor Ridge,
from which this image
is taken. In 1929 Gould's
party was the first to gaze
up this magnificent defile.
Blackburn's party traversed
along the east side of the
glacier, camping at the
northern end of the Zanuck
massif, the prominent fea-
ture with three summits.
With cirques and small
hanging glaciers halfway
up its face, Mount Zanuck
is the twin-peaked central
summit. To the right, rising
out of Scott Glacier, is Griz-
zly Peak, a beacon that can
be seen from both ends
of Scott Glacier. The sum-
mit to the left of Mount
Zanuck is unnamed. At the
head of the glacier the La
Gorce Mountains are lost
in cloud.
