466 Transactions. — Geology. 



boulders such as are not found in the ordinary gravels. But 

 the shapes of the hills are not those of ordinary moraines left by 

 glaciers: they are more of the nature of eskers — that is, low 

 ridges composed of water-worn materials roughly stratified in 

 places. 



The Moeraki Downs show do trace of morainic origin. They 

 are ordinary sand and gravel beds, standing out above the 

 plains to a height of about 100 ft. How could they have been 

 deposited ? Certainly not under the present conditions. The 

 rivers, when the gravels of the Moeraki Downs were deposited. 

 must have run at a much higher level than they do now. 



On the flanks of the Malvern Hills there are also patches of 

 gravels resembling those of the Canterbury Plains. I have 

 examined them in the neighbourhood of Sheffield, and estimated 

 that they go to a height of 50 ft. to 70 ft. above the plains.* 

 Again, at Fighting Hill, on the south-western side of the Malvern 

 Hills, there is a bed of gravel, 1,700 ft. above the sea, which is 

 not morainic in origin. It resembles a bar across the entrance 

 to a sound or river, and it is impossible to imagine that it could 

 have been built up by the Rakaia. 



I have not examined the hills near the gorge of the Ashley 

 on the northern boundary of the plains, and so I cannot say if 

 any high-level patches of gravel are found there ; but in the 

 railway-cuttings north of the Waipara gravel-beds are found at 

 a considerable height above the level of the plains. f 



On Banks Peninsula there are no gravel-patches similar to 

 those of the Canterbury Plains — nothing but fragments of local 

 volcanic rocks covered by the silt-deposit which I have already 

 mentioned. 



Before trying to explain the origin of these high-level gravels 

 it is necessary to consider two remarkable topographical features 

 in the plains — I mean the lower gorges of the Waimakariri and 

 Waipara Rivers. The first of these I brought to the notice of 

 this Institute in a paper read on the 15th November, L883 ; but 

 it is so long ago that perhaps I may be allowed to draw your 

 attention to it once more. 



The Waimakariri. after debouching on the plains, is joined 

 by the Kowai, coming from the south-west, and the two united 

 rivers make straight for Gorge Hill and cut it in two, thus form- 

 ing the lower gorge of the Waimakariri. which is crossed by the 

 railway between Sheffield and Oxford. The hill is composed of 

 sandstones, and rises about 2 70 ft. above the plains. J Above the 



♦"Geological Reports," ls::i 74, p. 56. 



v Trans. N.Z. [nst., vol. XX.. |>. 263. 

 J Trans. X.Z. lust., vol. wi.. p. 44!). 



