ALASKA GLACIERS 
186 
give little suggestion of the original mountain forms from 
which they were derived. They are irregular alike in 
their larger and smaller features. 
If the forms of land in this part of Unalaska Island were 
constructional, the sinuosity of the coast might be ascribed 
to irregularities of volcanic eruption; but as they are ero- 
sional, the deep embayments between steep-sided points 
and islands, and the dearth of plains near sea-level, point 
toward a somewhat recent subsidence of the land or rising 
of the sea. 
Spurr describes a series of terraces near Unalaska Bay, 
ranging up to a height of 1,500 feet, ascribes them to 
marine action, and infers a gradual rising of the land in late 
Pleistocene time. 1 He notes also that the village of Iliu- 
liuk stands on a spit which is evidently of recent formation 
but is shown by its vegetation to be above the reach of 
storm waves, and infers that elevation of the land is now 
in progress. The last mentioned observation I was able 
to verify, but I was not satisfied that any higher terrace I 
saw had been formed by the sea. 
BERING SEA 
The most extreme and contrasted opinions have been 
advanced with reference to the Pleistocene condition of 
Bering Sea. It has been stated by one high authority 2 
that the western coast of Alaska, the eastern coast of 
Siberia, and various islands of Bering Sea, are all glaciated 
in such a way as to indicate the occupation of the eastern 
part of the sea by an ice-sheet; and it has been asserted 
1 Eighteenth Ann. Rept. U. S. Geol. Survey, Part iii, pp. 266-267, 273, 276, 
1898. 
2 John Muir. On the Glaciation of the Arctic and Subarctic Regions visited 
by the U. S. S. Corwin in the year 1881. Rept. Cruise of the Corwin, 1881, 
Washington, 1885. 
