Philosophical Institute of Canterbury. 423 



Captain Hutton, in the same paper, observes : — " It is so universally 

 acknowledged amongst geologists that river terraces prove elevation, that it is 

 quite imnecessary to go over again such well-trodden ground," and he brings 

 forward a formidable array of scientific authorities in support. However, 

 nobody ever, doubted his statement, but he forgets that there is still another 

 and important agency by which terraces are formed, and which, not only in 

 New Zealand, but in many other mountainous regions, has been the principal, 

 if not sole, cause of their formation — namely, the retreat of the river sources 

 to higher and more distant regions. In my different reports, already cited, 

 I have treated of that subject at length, and shown why and how rivers with 

 less velocity do gradually lower their beds, so that I need not repeat myself 

 here. 



But a still more formidable objection to Captain Hutton's hypothesis 

 presents itself : if the Canterbury plains were of marine origin, the beds of 

 which they are composed would have preserved some traces of it ; but, 

 although we have clear sections several hundred feet high in almost every 

 river, their fluviatile character is unmistakable. The boulders, shingle, 

 gravel, sand, and ooze are all deposited as a river torrent would place them, 

 according to their form and size, and according to the greater or less amount 

 of water being brought down. The peculiar character of surf shingle is 

 nowhere exhibited, but all the pieces of stone have the subangular form so 

 peculiar to river shingle. Marine fossils are missing throughout. Moreover, 

 if elevation had taken place during the post-pliocene or glacier period. Banks 

 Peninsula would certainly show this most conspicuously j but what does a 

 close examination of that interesting, isolated, volcanic region reveal to us ] 

 We observe no trace of marine action, except the results of a slight oscillation 

 of about 20 feet, by which the peninsula has been raised after undergoing 

 probably a similar submergence. It is true that its lower portion in several 

 localities, up to 800 feet, is covered more or less with silt — a fine loam — which 

 in many instances is a true slope deposit, partly derived from the decomposition 

 of the rocks in sitil, or partly brought down from higher regions by running 

 water. Moa bones and pieces of small land shells have been found in these 

 deposits, of which there are many splendid sections to be examined, but 

 nowhei'e could the least sign of marine life be detected in them. 



This fact alone shows that the emergence theory has not the least foundation ; 

 on the contrary, from the nature of these silt beds and their partial denudation, 

 we might conclude that the peninsula has undergone a depression since they were 

 deposited. Had a rise of the ground taken place, by which the Canterbury 

 plains had emerged from the sea, we certainly should find the proofs of it along 

 the slopes of the peninsula in the form of raised beaches, deposits of sea 

 shingle and sand with recent marine shells, but nowhere is a trace of such 



