Canterbury and Westland. 231 



CHAPTER IV. 



Plains. 



On both sides of the Southern Alps, and amongst the secondary- 

 ridges, plains, varying in size and character, have been formed by the 

 disintegration and destruction of the rocks, from which this gigantic 

 mountain system has been built up, the detritus being brought to 

 lower regions, first by glaciers, and secondly by fluviatile action. As 

 previously pointed out, when speaking of the orographical features of 

 the country, the action of the huge glaciers formerly existing, has had 

 a most beneficial effect in preparing the surface for a dwelling place 

 of the human race, and for following the civilizing pursuits of agri- 

 culture and manufacture. Such useful results are especially apparent 

 in this portion of New Zealand, where, without the occurrence of the 

 G-reat Glacier period, the sea would still beat against the out-running 

 spurs on both sides of the Southern Alps, instead of washing against 

 the low shores of broad and fertile plains, by which the great 

 mountain chain is now fringed. Owing to the peculiar configuration 

 of our Alps, and the effects of sea currents and tides, the largest 

 portion of these plains is situated on the eastern side of this island. 

 The most prominent amongst these are the Canterbury Plains, which, 

 by their position, nature, and general characteristics, form a pro- 

 minent feature in this island, and are already the centre of a rich, 

 industrious, and large population. They begin at the dolerite plateau 

 of Timaru, and stretch without interruption to Double Corner, in a 

 general direction from south-west to north-east, with a length of 

 -about 112 miles. Their breadth from a few miles at both extremities, 



