Smith. — On Changes in Level of Coast Line in North Island. 399 



that island having glaciers, which this has not, or at least only to a 

 very limited, and perhaps doubtful, extent on Euapepu, The origin and 

 period of greatest extent of such glaciers has given rise to more than one 

 controvery in which this question of elevation or depression bears an im- 

 portant part. It is also premised that these notes will relate only to the 

 latter or recent period, not to the vast geological ages that have passed, during 

 which our hills and mountains rose out of the sea, and in using the term 

 recent it should be understood that it is in its geological sense it is referred 

 to, that is, to the period including the traditions, but extending backwards 

 far beyond it, during which the present outline of the country remained not 

 materially different to that we see at the present day. 



In a question of this kind it is of importance that we should understand 

 what kind of evidence we may expect to find, either of elevation or depres- 

 sion. Of the former, raised beaches, terraces, inland cliffs, or lines of sand- 

 hills, are the principal and may be more easily read, whilst depression is to 

 be looked for in the prolongation of the valleys under the sea, by finding land 

 surfaces in sinking to depths now below the sea-level, and in some cases 

 perhaps, by the character of the vegetation on the mountains in particular 

 spots, by the plants and animals inhabiting the islands off the shore, by the 

 depth of water along the coast line, and other indications, few of which are 

 however so capable of direct demonstration as the facts of elevation. It 

 requires, indeed, a practised eye to detect and interpret most of these 

 hidden records of the past, but when once the attention has been drawn to 

 them, it is marvellous how numerous they are, and the interest it gives to 

 many an otherwise tedious journey, to follow them out, and recognize in 

 each new feature some further evidence of the truth of the interpretation 

 placed upon them. There are occasional difficulties, however, in separating 

 the effects of sub-aerial denudation — which has been the active agent in 

 carving out the greater part of our hills and valleys — from those due to the 

 action of the sea ; but setting these doubtful cases on one side, there is 

 still a residium of proof sufficient to demonstrate the facts of elevation or 

 depression, though it can scarcely be expected that in the long ages to which 

 such records have been subjected to the war of elements, that they should 

 appear as fresh, or as easily deciphered as the result of forces in action at 

 the present time. Therefore in speaking of raised beaches, it must not be 

 supposed that these present a similar appearance to the beaches of our 

 present coast line, or that the sands, shells, or rocks are to be seen as 

 cleanly washed as by the daily tide. It is often a mere line, a fragment of a 

 terrace, or isolated mound covered with vegetation, that indicates the coast 

 line of the past. Whilst allowing fully for the immense, and almost incon- 

 ceivable, power requu'ed to elevate or depress the solid land, we could hardly 



