414 Transactions. — Miscellaneous. 



Waikato basins. The cause of the changes is a physio- 

 graphical question of great interest. There can be httle 

 doubt that the lakes which are seen to have occupied the 

 lower areas in each basin successively were caused by the 

 impounding of the waters of the river. By what was the im- 

 pounding caused? It seems to me to be accounted for by 

 either of two causes — the damming-up of the old river-bed or 

 oscillations in the level of the land. We have ample evidence 

 that at least a very large portion of the North Island has been 

 submerged, and again rose above the sea. Speaking of the 

 changes of level at the Thames Captain Hutton says, " It 

 would thus appear that when the alluvium, full of boulders, 

 found on top of the hill near Shortland was forming, the land 

 was 1,000ft. lower than at present; that it then gradually 

 rose until it was at least 100ft. higher than now ; and at that 

 time the Thames ran further north than Shortland. The 

 land then sank 10ft. or 12ft. lower than now, and subsequently 

 has again risen to its present level." Now, if these move- 

 ments of elevation and depression were uniform throughout 

 the island, when the land was 1,000ft. lower than it now is 

 very little of the North Island was above the sea, only the 

 high country in the interior, with our other high hills, appear- 

 ing as islands off the coast. 



Mr. Percy Smith has shown us very clearly that elevation 

 has been the latest movement. A very clear case of an 

 elevation of at least 15ft. is shown by him to have occurred 

 in recent times at Miranda, in the Hauraki Gulf, and the 

 settlers there are of opinion that the land on the flat re- 

 ferred to by Mr. Smith continues to rise gradually. One 

 settler informed me that he was enabled to sink a drain 

 1ft. lower than he originally sank it, twelve years ago, aiid 

 he feels convinced the tide does not now rise in the drain 

 within a foot of its former height. We may now imagine 

 the land (having sunk) again gradually and uniformly rising 

 from the sea. The Waikato Eiver may have occupied the 

 bed it now does before the submergence. We should then 

 expect its old valley to be filled with the detritus and alluvial 

 materials. In the subsequent elevation the river might have 

 first found its way to the sea on the east coast, through the 

 Waiotapu Valley. As the land rose gradually and uniformly, 

 the river would erode its bed deeper into the loose materials, 

 and we might imagine, as the high land to the eastward 

 came above the sea, its elevation being greater than the low 

 valleys in the upper basins, the water to be impounded and a 

 lake formed until such time as the river, having resumed its 

 old course, by degrees removed the detritus which filled it, 

 and so emptied the lake. If we still imagine the same to 

 have occurred at Hiuuera, where the second change took 



