594 Transactions. 



the railway-line northward for half a mile or more, occupying the lower 

 portion of the Kaikorai Basin. It was known to and figured by Hutton* 

 as far back as 1876, Its south-east slope is knobby and hummocky, the 

 hummocks in many cases enclosing undrained hollows between them, while 

 its upper surface presents smooth, flowing contours. The material consists 

 of peaty clays containing moa-bones, generally much decomposed, stiff 

 yellowish-brown clays containing an irregular bed of bouldery gravel, fol- 

 lowed by clays and a confused mass of boulders. 



At present, however, I am not so much concerned with the particular 

 manner in which the Taieri and Kaikorai glacial deposits were laid down 

 or formed as with what the deposits stand for. They mean that a gigantic 

 glacier or ice-sheet descended from the distant main divide in western 

 Otago to the present coast-line, occupying the Taieri and Tokomairiro 

 basins from Dunedin to the Clutha, and presenting a continuous ice-face 

 over forty miles long. The debris it has left in its track proves that it 

 rode over the coastal range on its way to the sea. This ice-sheet crept 

 across the uplands of Central Otago, which present no dominating or 

 leading valley leading to the Taieri Basin. 



The present canon of the Taieri Kiver, in Central Otago, and 

 gorges of the Waipori and Clutha, as well as the lower gorges of the 

 Tokomairiro and Taieri, that cut through the coastal range, are admittedly 

 features of comparatively recent date, excavated since the recession of 

 the ice. 



The glacial deposits in the Waikouaiti Valley, in the lower valleys of 

 the Waitati and Canterbury rivers, at the south end of Lakes Rotoroa 

 and Rotoiti, and at Boulder Lake, all attest the eastward advance of the 

 land-ice, and the widespread magnitude of the glaciation. Such intense 

 refrigeration as this implies could not but affect the North Island ; and 

 of this we have ample evidence provided by the great glacial till in the 

 Hautapu Valley, on the Wellington-Auckland Main Trunk line. 



In the vicinity of Dunedin we find that Saddle Hill, Maungatua, and the 

 uplands facing the Taieri Basin, Flagstaff, Swampy Hill, and the hills on 

 each side of Otago Harbour, everywhere present smooth, flowing contours, 

 in many places impressed with fluviatile featirres of later date. Flowing 

 contours, domed hills, and truncated spurs are the work of no known 

 agency but ice. It is admitted that an ancient glacier or ice - sheet of 

 enormous size occupied the Taieri Basin. How, then, can we, if we view 

 the position without prejudice or bias, deny that ice was the active agency 

 in forming these flowing features when we know that a gigantic glacier 

 existed so near at hand ? Whatever the cause of the Ice Age, we cannot 

 escape the conclusion that when the Taieri glacier extended to the sea, the 

 climatic conditions on the east coast of Otago must have been antarctic ; 

 and all polar discovery has shown that under such intense refrigeration 

 every valley would be filled with glacier-ice, and the whole region a waste 

 of ice and snow. 



In my Bulletin^ on the Wakatipu region I referred to the Kaikorai 

 boulder-clays as glacial, and not, as assumed by Dr. Marshall, to the clays 

 that lie along the summit of the ridge on which Maori Hill, Roslyn, and 

 Mornington stand. These clays are obviously residual, and as such have 

 always been described by me. 



* F. W. Hutton, " Geology of Otago," 1876, pi. vii. 



t J. Park, Bulletin No. 7, N.Z. Geol. Surv., p. 43; 1909. 



