Cussen. — Notes on the King Country. 825 



stood 3,000 feet lower than it now stands ; in which case it 

 would be of much interest in studying the changes in the level of 

 the country, as connected with the great volcanic movements in 

 the Taupo volcanic zone, and pointing to the existence of much 

 higher land, as occupying what is now the position of Taupo 

 Lake. 



Pleistocene Beds. 



The only other formations which remain to be mentioned 

 comprise the recent deposits in the river valleys, consisting of 

 the loose materials brought down from the higher ground by the 

 surface water and running streams, and including the detritus 

 from the various formations mentioned. Of these deposits the 

 most interesthig and important developments occur in the 

 valleys of the Upper Whanganui and its tributaries. The 

 mountainous nature of the country gives to the streams the 

 character of mountain torrents. The soft marl formations, 

 loose superficial pumice, and tolerably soft tufaceous rocks of the 

 district are all much subject to the ordinary effects of subaerial 

 denudation, and in consequence of these agencies almost incre- 

 dible quantities of matter are brought down by the rivers and 

 streams after every fall of rain. The surface configuration of 

 the country is undergoing constant alteration, new landslips 

 constantly appearing on the mountain sides, some of them of 

 great extent, carrying away large forest trees and masses of 

 rock, frequently damming up the courses of streams, and 

 forming temporary small lakes. Unfortunately, the greater 

 portion of the material deposited in the river valleys, and that 

 which occupies the surface, covering up the fertile soil derived 

 from the marl formations, is the superficial pumice deposit to 

 be referred to more particularly later on. Many of the valleys 

 are filled up to a great depth with pumice sands ; sometimes in 

 terraces ; sometimes in level plains. 



In the valley of the Ongarue these pumice beds display a 

 regularly stratified form of deposit, particles and blocks of 

 various sizes up to a foot in diameter lying in alternate layers of 

 finer and coarser fragments. With them are interbedded fine 

 layers of argillaceous strata, and trunks and branches of trees 

 partly changed into charcoal. These facts go to show that the 

 valley was once the bed of a lake ; the stratified pumice beds 

 and horizontal terraces could only result from still-water deposit. 

 The valley of the Whanganui, above its great bend at Tauma- 

 runui, is also filled up with great beds of loose pumice, in places 

 2 miles wide and over 100 feet in depth ; it seems probable that 

 these were also lake beds at one time. The most noticeable of 

 these is the Eena Plain, 10 miles east of Taumarunui ; its width 

 is nearly 2 miles, and its length about 4 miles. The river has 

 cut a deep channel through the pumice beds, which are over 100 

 feet in depth at the lower end of the plain, where the river course 



