32 Smithsonian Exploration in Alaska in 1904 



entirely, of changes of level in the earth's crust which have occurred 

 since Pleistocene times." 



Howorth's ideas as above expressed are supported by the facts in 

 Alaska as far as known, particularly in his contention that the Ice 

 beds, or so-called " Ground-ice formation " of Dall, or " Fossil-ice " 

 of Baron Toll, did not precede the Mammoth age and, therefore, 

 does not belong to the Pleistocene period. 



How generally accepted is the opinion that the Ice beds are older 

 than the Mammoth may be gathered by the following from Geikie : °* 



" There cannot be any doubt, therefore, that this remarkable sheet 

 of dead ice must date back to Pleistocene times, and is obviously of 

 the same origin, as Dr. Penck remarks, as the frozen bottoms or 

 grounds which are so commonly met with in the higher latitudes of 

 North America and Asia. Since the Mammoth and its congeners 

 disappeared, no similar accumulation of ice has formed in that region 

 — the dead ice is not being added to, but is gradually wasting away, 

 and Dr. Penck '* is clearly right when he says that the ice masses 

 of Eschscholtz Bay belong to an older period, when the climate of 

 those northern regions was considerably colder than it is to-day. 

 The frozen grounds of the far north are, in short, the equivalent in 

 time of the old glacial phenomena of our temperate latitudes. The 

 ice masses of northern Alaska are not the relics of any glacier or ice 

 sheet, for we have no reason to believe that those tracts have ever 

 been glaciated. They simply represent the drifted snows of Glacial 

 times which accumulated in valleys and depressions outside of the 

 ice-covered regions. Protected under a covering of alluvial matter, 

 soil, and peat, they have, in those high latitudes, endured to the 

 present day." 



It appears strange that " the drifted snows of Glacial times " 

 should have collected and been preserved only in situations that 

 were at that time without question the bottoms of Pleistocene lakes 

 covered with water. 



Thus it is easy to see that the significance of these ice beds has 

 puzzled inquirers a great deal and explanations of their origin 

 hardly less discordant with the facts than those recorded above have 

 been entertained and defended. 



^^ The Great Ice Age, 3d ed., p. 665. 



'■' Deutsche geographische Blatter, Bd. IV, p. 174. 



