386 CLIMATIC CONDITIONS OF THE GLACIAL EPOCH. 



In the opinion of the present writer, the geological importance of the so- 

 called ground moraine has been greatly exaggerated. That a sheet of ice, 

 such as is imagined by the advocates of the continental glacier, would have 

 the enormous abrading power usually ascribed to it, and would transport 

 and deposit the detrital material thus detached from the bed-rock in the 

 manner in which the drift is distributed, is far from being proved. The 

 statements of the various explorers of the glaciated region of Greenland indi- 

 cate almost unanimously the iniimportance or the entire absence of moraines 

 under, upon, or in front of, the inland ice and its glacier appendages. The 

 photographs taken at various points along the coast show the same thing. 

 The region once occupied by the Greenland ice and now abandoned by it 

 has no such masses of detritus piled up over its surface as there should be 

 if ice was the great erosive agent, and if the distribution of the abraded 

 material were similar to that shown to have taken place in the case of 

 the Northern Drift. 



That the aid of ice has been invoked, by geologists writing on the drift 

 of this country, over large areas where in reality the work has been done 

 exclusively by water, seems to the writer a proposition capable of being 

 clearly established. It seems also to be beyond question that icebergs have 

 played an important part, especially in carrying and distributing the large 

 angular boulders which in many places rest upon the surface in such a 

 manner as to show that they could not have been placed in their present 

 positions by running water or bj' a general ice sheet. 



The uncertainty attached to every phase of the Glacial epoch in North- 

 eastern America makes all speculation extremely unsatisfactory in regard 

 to the character and amount of the climatic or topographical changes which 

 accompanied that epoch or were the cause of it. That it was a time of 

 greater precipitation than is now taking place is evident enough ; that it 

 was also a period of intense cold, as is generally assumed, cannot be admitted : 

 the palseontological evidence does not confirm this view. Even in the 

 immediate vicinity of the glaciated regions the temperature was only moder- 

 ately reduced. 



That during a portion of the time, at least, when ice was doing its work 

 in Northeastern America there was a much larger area of the continent under 

 water than there is now, cannot be doubted. This would render the cli- 

 mate more oceanic, and be eminently favorable to the formation of ice in as 

 high a northern latitude as that occupied by the region in question. A broad 



