258 Ancient Glaciers of N~eiv Zealand. 



formation. By denudation we understand not only the wear- 

 ing away of rocks by wind, frost, and rain, but also by the 

 more powerful action of ice and running water; the opera- 

 tion of which we can see everywhere about us. 



As the evidence of a synclinal axis is nowhere apparent in 

 the valley of Lake Wakatipu, we are unable to account for 

 its existence by the upheaval of the mountains on either side 

 of it. We are likeAvise at a loss to find any indication of the 

 rocks having been rent asunder by volcanic forces. The 

 formation of the valley can only be referred to the third 

 cause, that of denudation, or the slow removal, by ice and 

 water, of the rock that once filled it to a heisrht greater than 

 that of the mountains which now tower above it. 



It may seem strange at first sight that such an immense 

 amount of rock — measured by hundreds of cubic miles in 

 the valley of Lake Wakatipu alone — could have been worn 

 down and transported to distant places, by the slow action of 

 ice and water. This difficulty would be removed could our 

 readers examine the region about Mt. Earnslaw, whose sum- 

 mit can be seen from the lake, rising clear and brilliant above 

 the surrounding mountains. On its sides are blue regions of 

 ice ; these are the descending glaciers, — the keys that unlock 

 the secrets of the valley's history. In those streams of ice, 

 although they are of great extent and of irresistible power, 

 we see but the puny remains of the mighty river of ice that 

 at one time flowed through the whole valley of Lake Waka- 

 tipu. The extent of this glacier was probably only limited 

 by the ocean, whose waters undermined its terminal face, 

 and floated away the fragments in the form of ice-bergs, in 

 the same manner that ice-bergs are formed at the present 

 day on the coast of Greenland. It takes but a glance to 

 convince the pilgrim to the shores of Lake Wakatipu, that 

 this great ice-river was the engraving tool which, aided by 

 storm and frost, excavated in the living* rock the scene of 

 wonderful grandeur and beauty that is now spread out before 

 him. 



