Hill. — Taupo Plateau and Lake. 445 



Art. XLIX. — Taupo Plateau and Lake : a Retrospect and 



Prospect. 



By H. Hill, B.A., F.G.S. 

 [Bead before the Hawke's Bay Philosophical Society, 1th September, 1903.] 



Plates XLII. and XLIII. 



Very little is yet known as to the history of the Taupo Plateau. 

 Situated in the heart of the North Island, at an elevation varying 

 from 1,400 ft. to 3,400 ft., with a gradual slope to the Bay of 

 Plenty, it presents an area of exceptional interest to the geologist. 

 Hochstetter in 1859 saw a portion of it, and his journey from 

 Tokaanu at the south end of Lake Taupo to Tapuharuru at the 

 north end, and thence on to Rotorua, enabled him to understand 

 some of the geological aspects of this interesting region. But 

 he little realised the extent of the volcanic area, or imagined 

 that the whole of it was in a large measure directly connected 

 with the history of volcanic phenomena extending over a much 

 longer period than is usually assumed. We are so apt to view 

 the isolated volcanic areas of to-day in their limited extent that 

 we overlook the fact of the present areas of activity being 

 connected directly and continuously with the earth's history 

 from the time when the earth was a mass of molten matter. 

 It is certain that new areas of volcanic agency have begun 

 within the human period, and that volcanic cones have built 

 themselves as mounds of accumulation by the material that has 

 been thrown or has flowed from the crateral opening that is 

 made by the gyration of superheated steam or gas during and 

 following great earth-movements. But, whilst this is readily 

 conceded, it must be evident from the study of volcanic 

 phenomena and the distribution of volcanic products that vol- 

 canoes have always existed from the time when the solidifica- 

 tion of the earth's crust took place. Nor is there any reason 

 why many of the volcanoes now known should not be directly 

 connected with the earliest period of the earth's history. If 

 we assume that earth-changes have taken place without those 

 great cataclysms which the earlier geologists assumed as neces- 

 sary — and the evidence of the rocks is, fairly complete that 

 such changes were gradual and continuous — then it may be 

 asked, why should there not be volcanoes that have existed 

 through the varying changes of deposition as illustrated by the 

 stratified rocks 1 The science of geology teaches us that the 

 forces of nature are constant in their operation, although the 

 results from period to period may be dissimilar. The external 

 forces that are ever in operation in their action upon the earth's 



