SEWARD PENINSULA 
193 
4,700 feet — nourished in Pleistocene time local glaciers 
of some magnitude. These are attested by U-troughs, 
cirques, moraines, and moraine lakes. One of them 
passed southwestward beyond the foothills of the range, 
and may have reached the sea. Another approached or 
reached sea-level at the north. The Bendeleben Moun¬ 
tains, farther inland, also contained glaciers, but too small 
to push beyond the foothills. Among the York Moun¬ 
tains, which stand between Port Clarence and Cape 
Prince of Wales, and have an extreme height of about 
2,900 feet, were probably small glaciers, but, if so, they 
were wholly contained in the mountain valleys. Except 
for these local developments, the surveyed parts of 
Seward Peninsula — namely, the southern and western 
parts — were not occupied by Pleistocene ice. Over 
large areas the mantle of residuary waste lies undisturbed 
on the rock from which it was derived; and in these areas 
are angular and slender crags, as well as perched boulders 
of disintegration, lying in their original positions. Other 
large areas bear rolled gravels, associated with a series 
of marine terraces. 
One of the marine terraces described by Collier and 
Brooks was seen by us along the southern base of York 
Mountains. It is there a conspicuous bench, ending sea¬ 
ward in a steep bluff, and has a height of about 600 feet. 
According to Collier, its uplift has been unequal, so that 
the old marine plane is now a warped surface. The fact 
of warping also accords with my observation, for such 
parts of the neighboring Siberian coast as I was able to 
study from the ship seemed altogether free from marine 
terracing. 
An observation of progressive modern change of level 
was made on St. Matthew Island. A small bay on the 
east shore, near Glory of Russia Cape, has been cut off 
from the sea by a series of shore bars. After the first bar 
