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 fauna of our coasts.* But much has 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 derived 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 during 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 paper 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 metamorphie 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 débris resting on the surface. But 
inthe 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 
débris by which it is covered, indicating the enormous erosive action which 
18 in progress. 
Owing to the softness of the rock that forms many of the narrow ridges which 
constitute cóls, which I have examined in this mountain district, these heights 
are being rapidly eut 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 past 
* The original application of the word Pleistocene included Upper Pliocene. 
