"234 GLACIAL ACTION IN AUSTRALASIA. 



contain A^ery few scratched stones. They are recognised by their 

 composition and their position. Lateral moraines may sometimes 

 be mimicked by landslips, but there is hardly ever any doubt 

 about the true nature of a terminal myraine. 



Karnes and Drumlins. — It is doubtful whether any of these 

 •exist in New Zealand. Small detached hills, formed of morainic 

 deposits more or less mixed with rounded gravel, occur near the 

 western margin of the Canterbury Plains on either side of the 

 Malvern Hills— Woolshed Hill, Racecourse Hill, and Little Race- 

 course Hill — but these are certainly not drumlins, and probably 

 they are merely relics of terminal moraines, the greater part of 

 which have been washed away by the rivers. 



Erratics. — No true erratics — that is, blocks which have been 

 transported from one drainage system to another by ice — have 

 iDcen recognised in New Zealand. Our erratics are merely large 

 angular boulders brought do^vn the valley, from the sides of which 

 they have been detached ; but sometimes they have crossed from 

 one side of the valley to the other. No sea-borne erratics have 

 "been noticed. 



Till Deposits. — The only kind of till found in New Zealand is 

 what is called " surface-till " or "moraine-till," characterised by 

 being sandy and containing large angular unscratched stones. 

 This is merely the surface moraine of a vanished glacier. No 

 sub-glacial till (u- boulder-clay — characterised by being formed of 

 tough clay containing more or less rounded stones generally 

 scratched or facetted — has as yet been recorded. Neither is there 

 any stratified floe till. Even the ancient moraines of the west coast, 

 Avhich stretch into the sea and form cliffs along the shore, show no 

 stratification, and no marine shells have ever been found in them.* 

 Hoches Moutonnees and smoothed Surfaces. — These are not un- 

 common, and are particularly noticeable and fresh looking in the 

 A'alley of the Rakaia, and in parts of N.W. Nelson district. In 

 Otago the rock surfaces have undergone much more weathering 

 than further north. This may in part be due to diiferences in the 

 nature of the rocks, and in part to differences in climate, and 

 consequent differences in the rate of weathering. 



Ice Grooves on Bedrock. — A few cases on the sides of valleys 

 have been recorded, but none on the tojjs or near the tops of 

 ridges. Possibly this may be due to the absence of a protecting 

 cover of boulder clay. 



Conclusion. — It appears, therefore, that the ice age in New 

 Zealand consisted of a great extension of the valley glaciers of 

 the South Island, and that there is no evidence of the former 

 existence of an ice sheet, or of any floe ice or icebergs in the New 

 Zealand se^s. Also there is no proof that any of the glaciers, 

 even at the period of their greatest extension, reached into the sea. 



* Haart, Geology of i anterburj- and AVesiland, p. 378 ; and Hutton, Ann. and Mag. 

 >at. Hist., ser. 5, Yol. 15, p, 87. 



