344 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 19, 



their present position to faults or upheaval. The eastern side of the 

 anticlinal forms a succession of huge folds, dipping throughout at a 

 very high angle, but so much destroyed that at present the syn- 

 clinals form generally the summits of the mountains, whilst the 

 anticlinals of the folds appear now on both sides of the broad and 

 deep valleys between. 



These strata consist of dioritic sandstones, clay-slates, indurated 

 shales, and aphanitic conglomerate or breccia beds, which follow each 

 other in endless succession, and have a thickness of at least 25,000 

 feet. They appear to have been deposited during the gradual de- 

 pression of the sea-bottom, whereby they obtained such an enormous 

 thickness. 



It is evident from the character and position of the beds in ques- 

 tion, that the rivers entering the Palaeozoic ocean came from the 

 high land situated to the east of the present Southern Alps, and 

 that this land consisted of gneissic schists, quartzites, felstones, and 

 true clay-slates, as weU as of dioritic sandstones, and other rocks 

 similar to those under consideration. 



I have, in some instances, although rarely, met with small rolled 

 pebbles of granite, syenite, and porphyry. The conglomerate and 

 brecciated beds of the Southern Alps invariably thin out towards the 

 west. 



I may here observe that I have obtained from the Chatham Islands 

 specimens of fine-grained gneissic schists resembling closely the 

 lower series of our Alpine beds. 



It is remarkable that limestone rocks occur very rarely, as I found 

 only a few beds of dark calcareous flagstones. Fossils are also ex- 

 ceedingly scarce : as far as I have searched, over hundreds of square 

 miles of these rocks, I have found only a few minute bodies resembling 

 Tentaculites, a few fragmentary remains like Serpulites, some im- 

 pressions of Pucoids, and one single specimen of indurated shale 

 with the tracks of Annelides. It is difficult to conceive that such a 

 paucity of animal and vegetable life in the Palaeozoic seas should 

 have existed during the formation of these huge sedimentary strata, 

 or that the necessary conditions for the preservation of its fauna or 

 flora were so seldom offered. 



The very summit of the central chain, as for instance Mount Cook, 

 consists, as before observed, of these sedimentary rocks, except in 

 some few localities, where its S.W. and jN'.E. direction is somewhat 

 altered by westerly bends, and the underlying newer fine-grained 

 gneissic schists, felstones, quartzites, and contorted clay-slates make 

 their appearance ; the latter by their hardness have generally re- 

 sisted the disintegrating agencies much better than any rocks in the 

 Southern Alps. 



Below them, again, advancing towards the west, we meet with silky 

 clay-slates, changing soon into micaceous and chloritic schists, which 

 are succeeded by true mica-schists, gneiss, and gneiss-granite, form- 

 ing the western base of the Southern Alps, and invariably dipping 

 at a very high angle towards the east. To these two latter series "" 

 the auriferous rocks in this province are confined. 



