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GEOLOGY: W. E. EKBLAW 
over by southerly winds. In Inglefield Gulf, only the south side is thus bor- 
dered because the cliffs on that side are more continuous, and the winds carry 
the snow from the plateaus over in great quantities; whereas on the north 
side, more broken by rather large valleys, the winds are deflected down the 
valleys, and little, if any, snow is carried over. Similar differences occur in 
other fjords. 
The wedge drifts which form in gullies and small gorges near the top of the 
cliffs are genetically related to the piedmont cliffs, and consequently are dis- 
tributed in much the same manner. They, however, are included within 
limited areas, and though in places they may be considered continuous with, 
and part of, the piedmont drifts, in other places they are the only drifts 
formed, for all the snow is carried into the gorges and gullies by the winds 
which are deflected into them The character of the drifts is so closely a 
function of the topography, the direction of the wind, and the consistency of 
the show, that as any one of these factors changes in character, the drifts 
may also change In Grenville Bay, for instance, the south side is bordered 
by piedmont and wedge drifts, while the north side is almost bare of snow; 
and since the south side gradually changes its direction from northeast-south- 
west at its mouth, to a nearly due east-west direction toward its head, and the 
prevailing wind is a general south-by-westerly, a regular succession develops, 
from tiny wedge drifts near the mouth, to a full-fledged glacier at the head, a 
glacier heading in a cirque a mile from the coast. 
As long a quiescent neve covers the ground, and protects it from changes 
in temperature and from weathering, little disintegration or degradation can 
take place. It is only when the snow melts that the work begins. The melt- 
ing in North Greenland is not a rapid process. Even when the sun shines at 
its highest, the temperature of the air does not rise much above 55° F.; it is 
usually lower, though that of exposed soil and rocks may be considerably 
higher. The snow drifts melt rather slowly, fastest at their edges. 
Each of the kinds of drifts described produces different effects when melt- 
ing. The dome-shaped drifts on the level surfaces melt first at their periph- 
eral edges. The water formed is very near 32° F., and freezes at every drop 
of temperature due to cloudiness or change of wind so that excessive frost 
action takes place at the margin and just beyond, with consequent breaking 
up and disintegration of the rock. Often, too, the water freezes on the side 
of the drift away from the low sun, even at noondays, thus increasing the 
freezing action. Just beyond the margin of the drift, the temperature of the 
water is a little higher, and solifluction sets in. The disintegration of the 
rock, and the movement of resulting material, progresses in toward the 
center of the snow-drift covered area, as the drift melts back. Horizontal 
solifluction and consequent applanation terraces so clearly defined by H. 
M. Eakin, 1 are the immediate effect, and these in time result in reducing the 
plaeau top, or other plain surface, to a quite level surface, constantly being 
extended in area, and lowered. The process has been so well described by 
