IOO 
ALASKA GLACIERS 
are steeper than those toward the north. Close to the ice 
front the plain was interrupted by a low ridge of gravel 
(see fig. 54), a push-moraine associated with some small 
FIG. 54. SOUTH WALL OF VALLEY AT FRONT OF GREWINGK GLACIER. 
and recent advance of the glacier, and possibly a phenom¬ 
enon of the annual oscillation of the front. Farther out 
on the plain the course of a much larger moraine was 
marked by a crescentic line of mounds and short ridges, 
remnants of a once continuous morainic rampart that had 
been breached at many points by streams from the gla¬ 
ciers. I judged that this also was a pushed-up ridge, 
resulting from a plowing of the gravel deposit during a 
rapid advance of the glacier. It was not strictly parallel 
to the ice front in 1899, nor to its outline as mapped in 
1880, but was more convex downstream. Its middle 
part was 2,600 feet from the glacier in 1899, and its most 
southerly remnant 800 feet. In 1880 Dali observed a 
considerable amount of ice under the sand and gravel of 
these mounds, and I noted many kettle-holes resulting 
from recent melting of ice remnants under the gravel 
