74 Transactions. 



older epochs. The succeeding Permian was an epoch characterized by 

 earth-movement, and the intrusion of granitic and dioritic magmas on a 

 gigantic scale. 



The Palaeozoic formations contain an abundant marine fauna that in 

 many respects shows a curious resemblance to the contemporary faunas 

 of Europe and North America; but of the Psilophytales — the rootless and 

 leafless land-plants of pre-Devonian Europe — and of the prolific Carbon- 

 iferous flora of the greater continents there is no trace in New Zealand. 

 For an explanation of this we must look to the land-movements that 

 brought about the great Devonian-Carboniferous hiatus. And this leads 

 to the surmise that the ancient continent on the shores of which the 

 Palaeozoic sediments of New Zealand were laid down had no direct land 

 connection with the Palaeozoic land areas of the Northern Hemisphere — 

 a surmise further strengthened by the absence of the typical Glossopteris 

 flora of the hypothetical Gondwanaland of the South Pacific. 



But to return to the New Zealand area. After the cessation of the 

 Permian diastrophic movements already described, normal deposition con- 

 tinued without interruption throughout the Triassic and Jurassic epochs, 

 the sediments being derived from the denudation of the ancient continent, 

 which was now larger in area, having been augmented in size by the 

 addition of the uplifted Palaeozoic rocks of the New Zealand area. The 

 Mesozoic sediments consist mainly of alternating beds of deltaic sands and 

 muds, in places intercalated with marine beds containing a rich assemblage 

 of fossil molluscs that in general facies bears a striking resemblance to the 

 contemporary Mesozoic marine faunas of Europe. It is noteworthy that, 

 though beds of limestone are common in all the Palaeozoic formations; no 

 limestones occur among the Juro-Triassic strata of New Zealand. This 

 circumstance may possibly be ascribed to the prevailing deltaic conditions 

 of deposition, which, as we know, would not favour the growth of limestone - 

 building organisms. 



Up till the close of the Jurassic epoch New Zealand had not come into 

 existence, but for a million centuries rocky materials had been accumu- 

 lating on the site it was destined to occupy. The early Cretaceous wit- 

 nessed the birth of the new land. At this time there began two syntaxial 

 crustal movements that folded and ridged the Mesozoic and older rocks 

 into great chains. Of these, the Rangitatan, a north-east and south-west 

 movement, produced the main alpine chains, and the Hokonuian the north- 

 west and south-east transverse chains. These movements built up and 

 gave definite form to the framework of New Zealand as we now know it. 

 They were accompanied by rock-shattering and faulting, and the extrusion 

 of igneous magmas, mostly of basic and ultra-basic types. This period 

 of intense crustal movement also brought about the foundering and sub- 

 mergence of the ancient continent that had existed in the south from 

 Archaean times, shedding the materials of which the Palaeozoic and Meso- 

 zoic rocks were mainly composed. The disappearance of the parent continent 

 was doubtless a consequence of the process of crustal adjustment, or com- 

 pensation, arising from the emergence of New Zealand from the floor of 

 the ocean. 



The aphorism of Plato that a country is only as old as its mountains 

 contains more than a grain of truth, and in the case of New Zealand 

 is actually true. The mountain-chains came into existence in the early 

 Cretaceous, and it was in that epoch that the real history of New Zealand 

 as a geographical unit began. 



