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Tian G. Simrr 
by him, several more could be brought forward to support it, but 1 shall not enter 
upon them, as the state of the southern part of North America has no direct 
significance for the qiiestion to be answered here, That the northern parts, from 
California to Alaska and eastward to the northern United States, as well as north- 
wards to Labrador, Greenland, and the Arctic Islands wero lifted considerably above 
their previous level, cannot be doubted. About the time for the beginning of this 
elevation of the land the opinions are more different; Upham. Icesheets, p. 194, 
lets it begin already in niesozoic time and continue into the pleistocene, but most 
authors are inclined to refer the beginning of the rise of the continental mass to 
the last part of the tertiary era. 
About the amount of elevation above the present shoreline it is difficult to 
get any tolerably exact figures, but some given by Upham in the paper quoted 
above may perhaps serve. He estimates the upheaval to between 2,000 and ;-5,000 
feet generally and for the region about Mount Saint Elias he comes to 5,000 feet. 
That a very considerabie elevation must have existed at the beginning of pleistocene 
time is shown by the deep submarine valleys, cut down in tertiary strata. Upham 
also in several papers has tried to show that this uplift of the land was the cause 
of the glaciation, and other authors have held the same view; for instance Leconte, 
Changes of coast, also tries to show why the effect, the glaciation, came somewhat 
behind the cause. the elevation, as well as its own effect, the following subsidence 
again after its maximum, and so on. Bell, Glac. Phenomeua, has expressed the 
same opinion in a very cautious language. The question about the uplift of the 
land as the cause of glaciation 1 shall not enter upon, even if there are several 
facts in the distribution of land around the Polar Sea, effected by such an expansion 
and connection of coastlines as it would give rise to, which speak rather strongly 
for attributing a large part at least to it in the causing of glacial conditions. We 
shall see, however, what an elevation of the coasts and seabottom to a thousand 
feet or more means for the distribution of land and water around the pole and 
what consequeuces must have followed it. 
An elevation of 600 feet will transform the whole inner part of the Bering 
Sea from Unalashka over to Anadyr Bay on the asiatic side to oue immense plain, 
communicating by a broad valley, the present Bering Strait, with another plain of 
similar extension, with a coast trending outward, from that of the present time, 
near Cape Barrow. The whole chain of the Aleutian Islands will become a narrow 
peninsula with a high mountainridge aloug it, while the Alaskan Peninsula and 
the inner Aleutians form a coastrange of considerabie height and extension against 
the Pacific. In this region even an uplift of thousands of feet more will not extend 
the coast much farther out, but probably it would change a considerabie part of 
the Polar Sea between Cape Barrow and the Arctic Archipelago into dry land. At 
all events the broad connection between America and Asia which Leconte, Crit. 
Periods, p. 553, speaks of will come into existence, thus making possible the inter- 
