Stewaet. — Evidences of Change in the Elevation of the Waikato Distriet. 35 



If, agaiu, we suppose a bar of liarder formation than the rest of the valley 

 to have existed and which had dammed the waters back ; to be reduced 

 by the current, the same kind of changes would take j)lace in the channel 

 above, as we have considered would be effected by the raising of the land, 

 and the amount by which the dam had been lowered would be traceable 

 approximately, in viewing the levels of the old and new channels. 



In the lower and middle Waikato, the features of the country indicate 

 that possibly both these causes have contributed to the changes of the 

 position and levels of the river. At Mangatawhui the river leaves the 

 sandy alluvial flats and takes westward through the Tuakau Gorge to the 

 sea. If we view the country upwards from thence, we can observe some of 

 the more salient features of the scene. And we find on passing each 

 successive gorge through which the river has, in by-gone ages, cut its way, 

 that the banks are higher than they are below, presenting in the higher 

 reaches three, five, and even seven terraces, each indicative of a level for 

 the time being of the river, or lake-like stream, before these natural dams 

 in the gorges were lowered. 



The evidence also that at these ancient river levels, the waters found 

 other routes to the sea, nearly amounts to demonstration. So much for 

 the lowering of the river through the formation of the land. Eegardiug the 

 country having risen, it is, almost equally beyond doubt, that the sea once 

 washed the bases of the inland hills in the Thames and Waikato valleys. 

 In Vol. III. Art. 25, " Trans. N.Z. Inst.," Mr. Kirk gives a hst of littoral 

 plants, some of which he found established one hundred miles inland of the 

 present tidal influence. The natural inference that these plants were left in 

 the salt marshes, formerly at the base of the now far inland hills, by the sea 

 which receded as the land arose, supports the ox^inion expressed by Dr. 

 Hochstetter, and points to a comparatively recent elevation of the land. It 

 seems clear enough, then, that to both erosion of natural dams, and to an 

 elevation of the country, are to be traced the causes of the river now flowing 

 at from ten to more than one hundred feet (speaking well within the mark) 

 lower than it has formerly done. These estimations being from the sea to 

 the Maungatautari Gorge, to which division the present notes are mainly 

 confined. 



The speculative thought to which we are invited by these considerations 

 abounds in interest ; but when we find in the midst of alluvial sands, 

 occupying the place where once the ocean rolled, indubitable evidence of the 

 previous subsidence of the whole country, we find the subject increased in 

 complexity, and leading to fields of vast speculative study, Vv^hich topo- 

 graphers will not soon exhaust. The waters of the river have lowered, or 

 the land has been raised, or both combined. The extent of this we can 



