244 Geology of 



splendid horizon for sub-diyision, which owing to the want of fossil* 

 in most localities for the examination of beds of such enormous 

 thickness, is of great importance. These beds reach to the east coast, 

 and it is evident that only after they had been deposited and consoli- 

 dated, the great movement of the earth's crust took place, through 

 which they were uplifted and folded. 



The three sections of the Chromo-lithographed General Section Plate 

 will offer to the reader a clear insight into the general features of the 

 remarkable geological structure under review. Although faults and dis- 

 locations are not wanting, I have not hitherto found eruptive rocks any- 

 where amongst them, appearing to have been injected during the forma- 

 tion of the folds, or afterwards when further dislocations and faults were 

 formed. The most careful search alongtheeast coast has also not revealed 

 any plutonic or eruptive rocks to which a part in the folding of these 

 sedimentary strata might be assigned, and the vera causa of such enor- 

 mous changes in the earth's crust has therefore to be attributed to 

 single or repeated movements of a more general character, and to which 

 I have alluded, when quoting fron von Hochstetter's classical work. 

 The folding must have taken place, as before observed, shortly after the 

 deposition and consolidation of the Mount Torlesse formation, which 

 I consider to be of young palaeozoic age. After assuming their present 

 form — I mean to say, after the western wing of the anticlinal had 

 almost disappeared — new sedimentary rocks were deposited along the 

 western flanks of the central chain, being of deep water origin, and 

 mostly in the form of slates, of which a great portion, in course of 

 time, has undergone such considerable changes that some of the rocks 

 have quite a metamorphic structure. This has partly been caused by 

 the intrusion of granites, syenites, and hornblende rocks. They now 

 generally stand at a high angle, and are, moreover, full of quartz and 

 other mineral veins, containing gold and other valuable metals. Not 

 having been able to distinguish between the western older crystalline 

 metamorphic zone, of which I believe, as I have already stated, a 

 remnant is still to be found near Lake Hall, and the metamorphic beds 

 and the newer slates from which these latter have been derived, I 

 thought it expedient to colour, in the Geological Map, the whole as 

 old palaeozoic, leaving it to a more detailed examination in future years 

 to unravel the complicated relations in which they stand to each other. 

 Although carefully searching for fossils whenever I had an opportunity, 

 I was never able to discover any in these newer slates, nor am I aware 

 that other geologists visiting the West Coast after me have been more 

 fortunate. 



