Park. — The Great Ice Age of New Zealand. 597 



Laniplugh thinks that the preservation of the glacial forms was due 

 to the protection afforded by permanent snowlields. He argues that 

 during and for some time after the recession of the ice the refrigeration 

 would still be sufficiently intense to cause the formation of fields of per- 

 manent or nearly permanent snow that would protect the ground on which 

 it lay from subaerial waste or denudation, fluviatile action being confined 

 to the defined watercourses. The contention seems not unreasonable. 



When considering the genesis of the present topography of the Otago 

 Peninsula and neighbourhood we must not forget the influence the rock 

 formations would be likely to exercise in the development of characteristic 

 surface-forms. The rocks consist of a pile of basic and semi-basic lavas 

 — emissive and hypabyssal — alternating with beds of tuflt and breccia. 



These rocks rise to a height of 2,000 ft. or 3,000 ft., and from their 

 character and origin one would naturally expect them to form broken 

 ridges, diversified with frowning precipice and steep escarpment, as do the 

 piles of andesitic rocks in the Hauraki Peninsula. Instead of these, we 

 have everywhere the smooth outline and flowing contour commonly pre- 

 sented by intensely glaciated surfaces, diversified by stream - dissected 

 features. 



From Dunedin to Timaru the dominant feature of the topography is 

 the smooth, flowing contours, dome-shaped hills, and truncated crests ; 

 while everywhere the valleys are U-shaped. The amount of recent stream 

 erosion is surprisingly insignificant, and where it had taken place is easily 

 distinguishable from the glaciated surfaces. 



Glacial till is well developed between Puketeraki and Merton, and there, 

 as near Seaclift", it forms conspicuous hummocks and hollows. The 

 morame at the former is doubtless a continuation of that spoken of by 

 Mr. Christie* as occurring at Cherry Farm. 



The land-forms in the lower end of Waikouaiti Valley, and of the en 

 circling hills and ranges, everywhere bear unmistakable evidence of glacial 

 erosion. On the north side of the valley stand the basalt-covered hills, 

 Hawkswood, Bald Hill, and Mount Watkins, all of them presenting beauti- 

 ful ice-worn domes. The high spurs descending from Mount Watkins are 

 finely terraced in front and sharply truncated on the crest. 



From Moeraki to Oamaru, and thence northward to Timaru, the surface 

 of the land everywhere bears the impress of ice erosion, and no one can 

 view the landscape, with its beautiful smooth contours, domed and trun- 

 cated crests, without being struck with the small part fluviatile erosion 

 has played in modifying the ice-worn surfaces of the Glacial period. 



The floor of the Shag Valley from Bushey Park to the river, as first 

 shown by Captain Hutton, is occupied by glacial clays. 



The Waitaki is a U-shaped glacial valley. The great glacier which 

 occupied this valley descended from the main divide to the present coast- 

 line. It filled the Mackenzie Plain, occupying the present site of lakes 

 Tekapo and Pukaki. It received great accessions from the Hopkins, Hob- 

 son, and Ahuriri. It scooped out the basin of Lake Ohau, and ploughed 

 out the tiers of glacial shelves seen on the slopes of the adjacent ranges 



The Waitaki glacier received its chief accessions from the Tekapo, 

 Pukaki, and other basins that were filled with gigantic glaciers the surface 

 of which, judging from the ice erosion and truncation of the mountains 

 around the Mackenzie Plains, of the ranges lying east and west of Lake 



J. Christie, Oiftqo Daily Times, May, 1909. 



