374 Proceedings. 



resting undisturbed on the surface of the country. The extension of this 

 period of elevation back into pliocene times, which the author suggests, I am 

 quite willing to concede, if subsequent examination of our fossiliferous deposits 

 should prove the existence of a sufficient break between our pre-glacier marine 

 fauna and the existing feuna of our coasts.* But much Jias still to be done 

 before any decision on this point can be arrived at. The arguments which 

 affect the question can only be given in the form of detailed descriptions of 

 particular localities, as general arguments on such a subject, where the elements 

 of proof are dei'ived from different and often distant areas, cannot be received 

 as conclusive. I recommend the subject of the study of our soils, surface 

 drifts, and beach rocks to the members of the Society, and will take an early 

 opportunity of communicating the results of observations that I have made on 

 this subject duiing past years. 



With respect to the subject of glacier drifts and the formation of rock- 

 bound basins, on which we have also a very interesting ]:»aper by Captain. 

 Hutton, and with whose conclusions I, in the main, agree, there is still a wide 

 field for observation. The estimate I have been led to form of the rapidity 

 with which a mountain ice-cap performs its work of eroding the elevated 

 rock-mass into ridges and peaks is, however, very different from that of 

 Captain Hutton. After the first rough excavation has been performed, and 

 only the hard cores of crystalline or tough metaraorphic rocks have survived 

 the denudation, and when the valleys have all been perfectly moulded to 

 perform their functions as ice-gutters, then I grant that the process of waste 

 is very slow. Such a state of things may be found in many mountain 

 ranges, and there the glacier ice is generally characterized by its purity of 

 texture and its comparative freedom from debris resting on the surface. But 

 in the New Zealand mountains, especially those culminating in Mount Cook, 

 which are formed of rock masses of the most friable kind, such as crumbling 

 schists and slaty sandstones cleaved and jointed in every direction, that causes 

 them to break down with such facility, there, we learn from Dr. Haast, 

 that the ice of the glaciers is hardly recognizable underneath the lode of fine 

 debris by which it is covered, indicating the enormous erosive action which 

 is in progress. 



Owing to the softness of the rock that forms many of the narrow ridges which 

 constitute cols, which I have examined in this mountain district, these heiglits 

 are being rapidly cut through and lowered at the rate of many feet in a year ; 

 and, in several instances, true passes of low altitude exist, which show evidence 

 that they have been formed at a very recent period by this process. The rapid 

 change in the extent of the snow-line of the New Zealand mountains is also 

 very remarkable. Thus, owing to the prevalence of dry winds during the jiast 

 * The original application of the word Pleistocene included Vfper Pliocene. 



