424 ELIOT BLACKWELDER 
trains of débris which lie upon the surface of almost all the other gla- 
ciers of the region. 
The lower end of the glacier is encircled from mountain to moun- 
tain by a crescent-shaped moraine more than a mile wide, which 
rises but a few score feet above the foreland. It has the character- 
istic knob-and-kettle topography of terminal moraines in general, 
contains numerous small lakes and swamps, and is strewn with 
bowlders. The till consists largely of rocks of the Yakutat series (early 
Mesozoic ?), with the addition of many crystalline schists and intru- 
sives from the older formations. One of the most conspicuous varie- 
ties represented in the large bowlders on the moraine is the coarse 
graywacke-conglomerate of the upper portion of the Yakutat series." 
Between the inner edge of the moraine and the ragged border of 
the glacier lies a long, irregular lake, to which we have given the name 
Harlequin Lake.? The water is muddy with the rock-flour derived 
from the glacier. Occasionally during the day the crash of icebergs 
falling into the water may be heard, but disintegration here is much 
slower than it is along the front of the Alsek Glacier. The water 
of the lake is now discharged through a cut in the moraine and 
makes the D-ngerous River. On the borders of the lake and the 
surface of the moraine there is evidence that the lake waters have 
recently been much higher than at present, and that they have not 
always used the same exit as at present. A series of well-marked 
and unmutilated wave-built terraces encircles the lake on the moraine 
side at various elevations up to 100 feet above the present surface of 
the water. About a mile north of the present Dangerous River the 
moraine is intrenched by two dry outlet channels, which converge and 
join before reaching the outer edge of the moraine, so that’ they issue 
in a single channel. The channels are bare and strewn with gravel 
and bowlders. They are from 60 to too feet deep, and the bottoms 
1 The outer front of the moraine is bordered by an extensive outwash-plain. 
Near the foothills on the west this plain slants perceptibly outward from the mcraine, 
while nearer the Dangerous River the declivity is hardly perceptible. Shallow dry 
channels furrow the outwash at several places. Near the moraine the normal flood- 
plain of the Dangerous River is about 30 feet below the plain, but 5 miles nearer the 
ocean the difference is scarcely 5 feet. 
2 Named from the fact that a pair of harlequin ducks were the only living things 
seen upon it. 
