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 



