CussEN. — On the Walkato Biver Basins. 407 



book of nature is laid open before us. In its most legible 

 pages we may read — on the faces of the cliffs and on the 

 terraces, in the steep or gentle slope of the valley towards the 

 river, and in the character and condition of the soil — the half- 

 hidden history of the past. 



For years past my duties took me into every part of the 

 Waikato's basins from its source to the sea, and I had an 

 excellent opportunity to study its topography. 



These notes refer to a comparatively recent period, when 

 the surface-configuration of the country was very much as we 

 find it now, and not to the geological ages of the past, during 

 which the country rose gradually out of the sea and our river- 

 valleys were first formed. Only the salient points of the 

 subject can be touched in a short paper. The changes in the 

 course of the Waikato seem to have been four in number, a 

 long space of time intervening between each of them. The 

 first took place at the Wai-o-tapu Valley, twenty miles below 

 Taupo. The Wai-o-tapu has evidently been a large river- 

 valley. It is, in fact, a continuation of that above, through 

 which the Waikato Eiver takes its course from Taupo. The 

 direction and configuration of the valley lead to the conclusion 

 that the Waikato Eiver once flowed through it to the sea. 

 From some cause its course was impeded : the waters were 

 thrown back into the valleys above, which they occupied in 

 the form of a serpentine lake or a lake-like river, with many 

 arms spreading in between the spurs of the ranges. Eound 

 Tuahu, Ngautuku, and other hills between Atiamuri and 

 Taupo, may be seen the old lake-beds filled up with alluvial 

 deposits, in the valleys between the hills immense beds of 

 pumice and sand, sometimes 200ft. in depth, are seen in level 

 plains through which the streams have worn their channels 

 deep down to the bed-rock, disclosing stratified layers of drift, 

 pumice, and light sands, enclosing the trunks of trees and 

 carbonised wood. The worn, shore-like sides which surround 

 these pumice-beds, cliffs of tufaceous rock often plainly water- 

 worn, and the stratified character of the deposit, leave but 

 little doubt that a large area in this part of the Waikato 

 Valley was occupied by a lake. The waters found their next 

 outlet thi-ough the ranges between Whakamaru and Titirau- 

 penga. 



The elevation of the outlet was at first about 300ft. above 

 the present bed : gradually it was worn deeper through the 

 barriers, and the waters of the lake drained off, each successive 

 stage in the process of lowering being indicated by a well- 

 marked regular terrace round the south end of the gorge and 

 the lake-basins in the valley above. These terraces are of 

 immense proportions, and range fully 200ft. above the present 

 river-bed. 



