Canterbury and Westland. 245 



On the eastern side of the central chain, no rocks of the same age 

 lave been recognised by me, although some of the beds forming the 

 upper portion of the synclinals might be of younger age than the rest, 

 but in the absence of fossils and all the rocks possessing the same 

 lithological character, it has hitherto been impossible to trace any differ- 

 ence in age, the whole, without exception, appearing to belong to the 

 same series. I may here add that the large area of crystalline meta- 

 morphic schists covering a considerable portion of Otago, and in which 

 its principal goldfields are situated crosses near Lake Wanaka into the 

 Province of Canterbury. It has been coloured, in the G-eological Map 

 attached to this report, the same as the gneiss granite formation in 

 Westland. 



It is evident that for a long time, the eastern ranges have 

 undergone great denudations before any newer beds were formed. In 

 fact, the general orographical conformation of the country in its main 

 features and the lines of great valleys, and direction and form of the 

 great mountain chains between them had already been fixed, before 

 newer beds were deposited over them. "We may thus conclude, from 

 the evidence before us, that the Southern Alps after rising from the 

 ocean had been forming high land above its level for a long period. I 

 stated previously that on the eastern side of the eastern wing of the 

 great anticlinal, no eruptive rocks of contemporaneous origin were 

 existing ; however, it is evident that such a remarkable folding could 

 not have taken place without weakening the crust of the earth con- 

 siderably in the direction of the strike of the beds. The folding of the 

 strata having taken place in young palaeozoic times, but before the 

 auriferous slate formation at the "West Coast was deposited, an enormous 

 period appears to have intervened before new beds were formed, 

 because we have to reach the latest mesozoic times before we can trace 

 such beds with certainty. Eruptions on a large scale then began on 

 the eastern side of the anticlinal, stretching from the Orari south to the 

 Oxford hills north. The eruptions commenced with melaphyres, either in 

 the form of crystalline rocks or as tufas and amygdaloids, and they were 

 doubtless all deposited on the sea bottom, although no traces of marine 

 fossils have been discovered in them. These basic eruptive rocks 

 underwent in their turn, considerable denudations, before new out- 

 bursts, this time of an acidic composition, appeared in the same districts. 

 They consist of quartziferous porphyries of great variety with their 

 pitchstones and tufas, and generally follow the same line, partly 

 surrounding Banks' Peninsula, as a segment of a circle. They either 



