Parjc. — Tlie Great Ice Aye of iS'eiv Zealand. 589 



Art. LXI. — The Great Ice Age of New Zealand. 



By Professor James Park, F.G.S. 

 {Read before the Ofago Institute, 22nd September, 1909.] 



New Zealand geologists and physiographers have always agreed that 

 there was a period of intense refrigeration in the South Island in very 

 late Tertiary times, and all have agreed that this refrigeration was caused 

 by an elevation of the land. There has, however, been some disagreement 

 as to the extent and date of the glaciation caused by this refrigeration. 



With respect to the extent of the glaciation, Mr. J. T. Thomson and 

 Sir Julius von Haast maintained that the whole of the South Island was 

 covered with a continuous ice-sheet ; while Sir James Hector, Captain 

 F. W. Hutton, Mr. A. McKay, and Mr. W. T. L. Travers held the view 

 that the main Alpine divide was occupied by an immense icefield from 

 which gigantic glaciers descended to the sea on the west coast, and on the 

 east coast reached the Canterbury and Southland plains. The glacier 

 which occupied the Taieri Basin from near Dunedin to the south of Milton 

 was admitted by Hutton to have crept over the coastal hills to the present 

 coast-line. In the late " seventies " Haast modified his first view as to the 

 extent of the glaciation. Up till the year 1907, but without having made 

 any special review of the evidence, I gave a general support to the cor; 

 tention of Hector and Hutton. 



The Glacial period of New Zealand was believed by Hector, Haast, and 

 McKay to have taken place in the Pleistocene — that is, contemporaneously 

 with the Ice Age of the Northern Hemisphere. Hutton, on the other hand, 

 placed it at a somewhat earlier date — that is, in the Pliocene ; but in my 

 review* of the " Marine Tertiaries " of Otago and Canterbury I showed 

 that the Greta and Awatere beds of the South Island were older Pliocene, 

 and not Miocene, thus removing Hutton's difficulty as to the Post-pliocene 

 glaciation. 



During the progress of my geological survey of the Wakatipu regionf 

 in the summer of 1907-8, among new evidences of glaciation I discovered 

 that the mountains on the north-east side of the lake were covered with a 

 stony boulder drift up to the height of 4,000 ft., mainly composed of 

 erratics transported from the Livingstone Mountains, and that the moun- 

 tains were ice-shorn and cut into shelves up to a height of 6,500 ft. above 

 the sea. As a result of my observations, which are fully recorded in my 

 bulletin on the Wakatipu district, I estimated that during the glacial 

 period the ice formed a continuous sheet that stretched over the greater 

 part of the South Island, in the Wakatipu Basin attaining a thickness of 

 over 7,400 ft. In support of my contention that the ice-sheet reached 

 the sea on th.e east coast, I referred to the glacial boulder - clays near 

 Dunedin, the glacial drift overlying the coastal hills between the Taieri 

 Plain and the sea, and the loess at Oamaru and Timaru. 



* J. Park, Trans. N.Z. Inst., vol. xxxviii, 1904, pp. 536 and 547. 

 t J. Park, " Goology of Wakatipu Area," Bulletin No. 7 (New Series), N.Z. Geo- 

 logical Survey, 1909. 



