428 Transactions. — Geology. 



period when the area which they now cover was "a broad arm or channel of 

 the sea" to the full swing of the Pacific waves — would be very singular, for 

 Dr. Haast tells us that these waves were, at that time, sufficiently powerful 

 completely to undermine and destroy tertiary strata bounding the area in 

 question, and extending from Timaru to Double Corner. 



Further, these gravels have been subjected for countless ages to the action 

 of rain water percolating through them, which would, in all probability, have 

 removed any traces of comminuted shells, even had the quantity originally 

 been large. At the present time shells are rarely found upon any part of the 

 Canterbury coast line which is exposed to the surf, and but few are found, 

 and those only of comparatively fragile kinds, even within the area protected 

 from its action by Banks Peninsula. It must further be noted, too, that the 

 materials of which a large portion of the surface deposits of these plains is 

 composed are such as would, in the lapse of geological times, be converted into 

 very coarse sandstones and conglomerates, formations in which the preservation 

 of shell deposits is but little looked for. 



But, leaving this matter, I now propose to deal with the probability of the 

 alleged glaciation of New Zealand, judging of such probability from the 

 direct " causes " which Dr. Haast has assigned for it. It will have been observed 

 that these so-called " causes " are, in effect, summed up by the learned doctor 

 in two or three point-blank assertions, unsupported either by argument or 

 evidence ; whilst not a tittle of satisfactory explanation is vouchsafed as to 

 the " causes " which subsequently led to its disappearance. 



We are told that the South Island was repeatedly submerged during the 

 tertiary period ; and that, upon its final re-emergence, snow began at once to 

 accumulate, in enormous quantities, upon the surface, further elevation leading 

 to the formation of large glaciers, which at once began to eat back, I presume, 

 into the plateau-like range of mountains. And the only "causes" actually 

 assigned for the general glaciation which is alleged to have at once supervened, 

 and to have continued for the large but indefinite portion of time occupied in the 

 tremendous upheaval referred to— a glaciation, moreover, which is character- 

 ized by the doctor as being similar to that of Greenland and of the antarctic 

 lands, is " the insular and peculiar position of New Zealand, its principal 



runnimr 



angle to the two prevailing air currents, the equatorial north-west, and the 

 polar south- east, both bringing moisture with them." 



Dr. Haast gives us no reasons, however, for supposing that the insular or 

 other position of the islands has altered since the times referred to, nor does 

 he suggest any ground, deducible from known physical reasons, why the 

 glaciation he mentions, if it ever existed at all, should not still exist. The 

 winds which then blew are, even according to Dr. Haast. tfi ft sam* as thn 





