304 Transact ions . — Geology. 



geological science ; and if it be admitted, on the one hand, that when the 

 period began it found the existing systems of hill and valley in the main 

 detemnined, it must also be admitted, on the other hand, that it cannot have 

 left them exactly as it found them. The intensity given to denuding agents 

 by frost, or rather by the alternations between frost and thaw, is well known 

 to be enormous ; and it is impossible that a glacial period should have come 

 on, should have endured for a long period of time, and should have gi^adually 

 given way to a more genial climate, without having left upon the pre-existing 

 surface powerful and lasting effects. But the conclusion that the glacial 

 epoch deepened within certain limits pre-existing valleys, degraded to a like 

 extent pre-existing hills, filled up estuaries with moraine matter, or with sand 

 and gravel, or covered a great extent of country with boulder-clay, all this is 

 very different from the conclusion that our existing systems of hill and valley, 

 and even of sea and coast, have been all cvit out of the solid by some great ice 

 sheet of enormous thickness, which was quite independent of local glaciers, 

 and which did not derive either the cause or the direction of its motion from 

 the mountains which we now see." . Further on, after referring to the present 

 glacial conditions of Greenland and of the great antarctic continent, his Grace 

 says ; — " From observations such as these we may be assured, I think, of the 

 truth of the theoretical conclusion that lofty mountain chains, with all their 

 characteristic variety of surface, must, in all ages and in parts of the globe, 

 have preceded the development of glacial conditions, and that in these chains 

 the unequal elevations and depressions, which are the work of subterranean 

 force, have ever been the guiding and controlling cause of glacial action." 



Moreover, such a glaciation as Dr. Haast suggests in the report above alluded 

 to must necessarily have obliterated all but the scantiest fragment of the fauna 

 and flora of the country, leaving, indeed, at most but a few alpine forms 

 struggling for existence amidst the inhospitable conditions by which they were 

 surrounded ; whilst, on the other hand, the study of the existing forms of life, 

 and of those which have certainly become extinct within pleistocene times, has 

 led all who have engaged in it to a conclusion entirely at variance with any 

 such assumption. I propose, however, to deal with this question more fully 

 in a future paper. 



I will now proceed to describe, in some detail, the glacier phenomena 

 pi'esented to us in the upper parts of the valleys of the Buller and the Dillon, 

 which I have selected as well marked types of those which are exhibited in 

 other parts of the great mountain range of the Middle Island. 



These two i-ivers, as well as many other of the larger rivers in the northern 

 part of the island, have their sources in the great mountain system named by 

 me the "Spencer Mountains," which occupy the centre of the tract of country 

 comprising the Provinces of Nelson and Marlborough. The highest point of 



