Ancient Glaciers of JSTew Zealand. 263 



Other great changes probably took place, the records of 

 which have been erased. 



Not only, however, may we trace the past history of this 

 interesting lake, but we can also look beyond the veil that 

 obscures its future. As the combined actions of ice and 

 water have been the instruments for its formation, so are 

 they also working its destruction. After the formation of 

 the moraine at Kingston, the waters sought a new outlet 

 from the valley over the falls of the Kawarau, which are 

 constantly wearing away by the action of the water, and thus 

 tending to drain the lake to a lower level : we see, indeed, 

 by the terraces along its shores, that it has been already low- 

 ered. While the outlet is every moment becoming deeper, 

 the water that flows from the foot of the glaciers, together 

 with every rill and rivulet born among the mountains, is 

 continually bringing down its burden of sediment, however 

 small, which it deposits in the lake, and does its part towards 

 filling the valley. While at the upper end of the lake the 

 water is of a light-blue tint, caused by the foreign material 

 held in suspension, thus indicating its glacial origin, a few 

 miles down it becomes beautifully clear, and of almost as 

 deep a blue as the open ocean itself. 



The present conditions continuing, Lake Wakatipu will at 

 no very distant day, geologically speaking, have reached the 

 end that awaits all lakes, and be drained dry — the fate that 

 has already overtaken the lake which once existed to the 

 southward. 



Some of the able geologists of New Zealand are inclined 

 to attribute the former extension of the glaciers of the South 

 Island, solely to a greater elevation of the land. Such an 

 elevation may account very well for all the known facts re- 

 lating to the glaciation of that island. When we take into 

 consideration, however, the records left by ancient glaciers 

 on other lands in the southern hemisphere, — as in South 

 Africa,* where well-characterized moraines and transported 



* G. W. Stow, Quart. Jour, of the Geol. Society, xxvii, 550. 



