384 Geology of 



i 



Extent asd Chabacteeistics or the Glaciees. — Easteek 

 Slopes of the Southern Alps. 



It is natural that the highest portion of the Southern Alps,, 

 where the most considerable glaciers in lS"ew Zealand are still 

 found, must in the Great Glacier period have given birth to the 

 largest ice-streams, of the enormous size of which we can scarcely 

 form a true conception. Although in the map in illustration of this 

 chapter the outlines of their former size are given, I think that an 

 enumeration of the characteristic features of some of these glaciers, 

 as to size, form, dimensions, and remnants of their morainic accumu- 

 lations will be of some interest to the reader. 



The Waitaki Glaciee. 



The lowest portions of morainic deposits belonging to this glacier, 

 which I was able to trace, are situated on the left bank of the Waitaki, 

 six miles below the junction of the Ilakatararnea, rising about 600 feet 

 above the valley. From here to the sea the ranges bordering the 

 Waitaki are mostly all capped by alluvium, showing that at one time 

 the bed of that river has been lying at least GOO feet above its present 

 level. This is very conspicuous on the ranges between the lower 

 Waitaki and Waihao. Calculating from the position of the present 

 rt/iv-iields of the Takapo, lying about ten miles more distant than 

 those of the Tasman glacier, the total length of this post-pliocene 

 glacier was at least 112 miles. * 



During the greatest extension of the glaciers under review, four 

 principal and some minor branches came down by the valleys of the 

 Takapo, Pukaki, Ohau, and the Ahuriri, which uniting in the Mac- 

 kenzie plains formed a trunk glacier of a breadth of about thirty 

 miles. As the accumulating ice masses could not be discharged by 

 the valley of the "Waitaki alone, several outlets were formed in the 

 depressions between the mountain range on the eastern side of that 

 plain. These depressions are now known as the Burke's, Mackenzie^ 

 and Hakataramea Passes. Of these secondary branches the one 



* When publishing in 1S65 some notes on this and a number of other post-pliocene glaciers, I could 

 only give the results of my examinations up to that date. Since then, further and more detailed 

 researches have shewn the existence of morainic accumulations far in advance of the limits formerly 

 Assigned to them. 



