Canterbury and West-land. 375 



assuming a higher altitude of about 2000 feet for the central range- 

 to be not too great an estimate, the mean elevation of the country 

 (an important factor in our calculations) would have been still 

 greater, and from its form, still more favourable for the accumu- 

 lation of vast snow-fields, by which the limit of the snow line 

 would have been considerably lowered. I think, therefore, that I 

 have made a very moderate estimate in assuming that the snow 

 line was then 1000 feet lower than it is at present, taking all the 

 combining physical conditions into account. When we consider the 

 enormous amount of detrital matter brought clown by the rivers into 

 lower regions, the formation of the Canterbury and Westland plains, 

 the huge morainic accumulations all above the sea level, and the still 

 greater amount deposited in the sea, by which the sea bottom round 

 New Zealand must have been considerably raised, it is clear that an 

 almost inconceivable waste must have been going on for a long period 

 of time to shape our Alpine ranges into their present form. I have 

 introduced into this ideal section the actual section, I\o. 2 of the 

 general plate, in which the existing'perpetual snow-fields have been 

 shaded with a darker tint. Considering their small size compared 

 with those of the Great G-lacier period, and the fact that still glaciers 

 of such considerable extent can be produced by these so greatly 

 diminished snow-fields, it is evident that the prodigious neves, accu- 

 mulating at that time on the higher plateau-like ranges, must have 

 been able to form glaciers of such gigantic dimensions that we can 

 scarcely form a conception of it. During the geological examination 

 of the two provinces I have become acquainted with the boundaries of 

 the principal glaciers during the period under consideration, and I 

 have thought that their delineation on a map would convey, better 

 than words can do, an idea of the peculiar form and enormous size 

 they once possessed. In the map attached to this Report all the 

 information at my disposal has therefore been given. Many of the 

 glaciers had doubtless still greater dimensions than those marked in 

 the map; but in that case the morainic accumulations near their 

 former terminal face have either been washed away by the sea, or they 

 are now covered with alluvium. The area of the largest glaciers now 

 existing in our Alps has been shown by a darker tint, so that a com- 

 parison between both periods can easily be instituted. 



Before proceeding to give a short outline of the principal glaciers of 

 the Great Glacier period in New Zealand, it may be useful first 

 to state my reasons why I consider that the relations of land and 



