468 Transactions. — Geology. 



Two principal objections may be made to this hypothesis : 

 the first is the absence of marine shells on the plains ; the 

 second is the absence of high-level gravels on the slopes of Banks 

 Peninsula. Both, you will notice, are founded on negative evi- 

 dence, which has less weight in geology than in any other depart- 

 ment of science, on account of the imperfection of the record. 

 The first objection I will postpone until later. The absence of 

 marine beaches, or gravel-patches, on Banks Peninsula may lie 

 due either to the effects of subsequent atmospheric denudation, 

 which has washed them away ; or, which is more likely, the 

 gravel-beds never reached high levels on Banks Peninsula, on 

 account of its distance from the mountains. 



A third objection is the shape of the stones which form the 

 plains, which are not flattened as they should be if they had 

 been exposed to long-continued wave-action on a sea-beach. 

 But this objection would not apply to all the stones of the 

 gravel-beds, only to an upper layer ; and it is quite possible 

 that the submergence did not last sufficiently long for the 

 stones to assume the shape characteristic of a sea-beach. 



We now come to the silt or loess which lies above the gravels. 

 It is found in places all over the plains, and inland to Gorge Hill 

 or beyond it. It is also found all round Banks Peninsula, where 

 it is quite as well developed on the seaward as on the landward 

 side. Here it occurs chiefly on the tops of the ridges, having 

 been largely removed from the valleys by denudation. It i- 

 well seen in Lyttelton Harbour and along the Governor's Bay 

 Road, as well as all along the foot of the hills from the Dyer's 

 Pass Road to Sumner. On the coast between Lyttelton and 

 Akaroa it also forms thick deposits, a section of some of which 

 I gave in my paper in the " Transactions of the New Zealand 

 Institute," vol. xv., p. 413. Sir Julius von Haast, who examined 

 Banks Peninsula with considerable care, states that it goes up 

 to a height of about 800ft. above the sea; and. judging from 

 what can be seen when going along the roads to Akaroa, I think- 

 that he is right. Near Amberley it is sometimes covered by 

 fine river-gravels brought clown by the River Ashley. 



At Timaru the same deposit is largely developed, covering 

 the volcanic cocks and extending northwards over the shingle- 

 beds of the plains. It can be traced all the way down to Oamaru, 

 where it is as well developed as at Timaru. But after crossing 

 the Kakanui River we lose it ; or, rather, it changes into an 

 ordinary clay, with more iron in it than in the typical deposit. 

 These brown clays extend through Dunedin and South < >tag<> 

 nearly to the mouth of the Mataura, where we again come across 

 a silt exactly like that of Lyttelton, which continue-- over the 

 Southland plains t<> lnvercargill. and perhaps further — for I am 



