Ancient Glaciers of New Zealand. 261 



not by being interstratified with beds of till, but by the ex- 

 istence, both above and below it, *of distinct glacier- worn 

 valleys. It is similar in position to the inter-glacial lignite 

 beds of Switzerland, and to the inter-glacial forest beds of 

 Scotland and America. Like these northern formations, it 

 indicates a period of warm and genial climate, in the very 

 midst of the time of great cold. Geologists will notice, 

 however, the far greater age of the limestone of Lake Waka- 

 tipu, which, as indicated by its fossils, is Upper Eocene. 



The second glacier that flowed down the valley of Lake 

 Wakatipu, like the first, had its time of great extension and 

 then slowly passed away. As its terminus retreated up the 

 valley, it left behind it the material it had gathered from the 

 overhanging cliffs along; its course, or had torn from the sides 

 of the valley, together with the finer products ground by the 

 bottom of the glacier from the rocks over which it passed. 

 This material now forms the filling of the valley below the 

 lake, and has been worked over, perhaps many times, by the 

 action of water, which has left it in many regular lines of 

 terraces along the sides of the valley ; these giant stair-ways 

 often form a striking contrast with the angular crags and 

 rocks that tower above them. 



At Kingston, situated at the southern extremity of the 

 lake, a huge terminal moraine,* composed of cyclopean masses 

 of angular rock, has been thrown by the glacier directly 

 across the valley, and now forms the shore of the lake. In 

 this confused mass of rocks we have indisputable evidence 

 that here, for a long time, stood the terminal face of the glac- 

 ier, which ended abruptly — as is common with glaciers at 

 the present day, and as is notably the case with the Great 

 Clyde glacier, that ends, as we have seen, in a wall of ice 120 

 feet high. The rocks now forming the terminal moraine at 

 Kingston, were once lateral moraines on the surface of the 

 glacier ; and as the stream moved on and melted away, they 



* At M on the accompanying map. 



