Y. — GEOLOGY. 



Art. LYI. — On the Date of the Last Great Glacier Period in New Zealand. 

 By Capt. F. W. Hutton, F.G.S. 



\^Read before the Wellington Philosophical Society, \Sth September, 1872.] 



It is an acknowledged fact that the glaciers of the South Island of New 

 Zealand have been at some former time of much larger dimensions than they 

 are at present, and to the period of their greatest extension Dr. Haast has 

 applied the term " Glacier Period." This term is a very convenient one, and 

 I shall here adopt it with the understanding, however, that it has no relation 

 to, and implies no contemporaneity with, the " Glacier Epoch " of the Northern 

 Hemisphere; for although Dr. Hector ("Geo. Mag.," 1870, p. 70; KZ. 

 Exhibition Jurors' Keports, p. 263 ; Trans. N.Z. Inst., IL, p. 372 ; " Quar. 

 Jour. Geo. Soc," 1865, p. 128; and Anniversary Address to the Well. Phil. 

 Soc, 1872), and Dr. Haast (Formation of the Canterbury Plains, pp. 7, 14, etc.) 

 refer our last glacier period to pleistocene times, that is to about the same 

 time as the glacial period of Europe, I think I shall be able to show that it 

 is in reality far older, or at any rate that the subject is one that admits of 

 discussion. 



No New Zealand geologist advocates now a cold or glacial period to 

 account for the former extension of our glaciers, for, as Dr. Hector has 

 pointed out in his anniversary address for this year, there are no signs of any 

 till or marine formed boulder-drift to be seen, and our pleistocene and newer- 

 pliocene fossils show that no very great reduction of temperature has occurred 

 in these latitudes since those times*. In the pleistocene deposits, of Wanganui 

 we find Triton spengleri, Cassis pyruT^iy and another extinct species of the 

 same genus, Ancillaria australis, Turbo granosus, hnperator imjperialis^ 

 Rotella zealandica, and Labio zealandicus, as well as Mesodesma chemnitzii 

 and M. cuneata, none of which probably would have been able to survive a 

 reduction of temperature sufficient to cause so great an extension of our 

 glaciers as we know to have taken place. 



In the newer-pliocene beds which form the lower series at Wanganui 

 (Geo. Reports, 1872, p. 182) we also find a Typhis, the same extinct species of 



* It can by no means be inferred from this that there has been no ' ' Glacial Epoch " 

 in the Southern Hemispliere, for no glacial (as distinguished from glacier) plienomena are 

 found in Europe south of 50°, and i,t is%)robable that if no land now existed north of that 

 parallel of latitude the occurrence of a glacial epoch would never have been suspected. 



' • % 



