v.— G E L G Y . 



Aet. LXXXIY. — On the Geological Structure of Banks Peninsula, being an 

 Address by Prof. Julius von Haast, PH.D., F.K.S., President of the 

 Pliilosopliical Institute of Canterbury. 



[Read before the Philosophical Institute of Canterlury, 7th March, 1878.] 



Gentlemen, — Being called again by your vote to the honourable position of 

 presiding at your meetings, the agreeable duty devolves upon me to address 

 you to-night at the opening of the session 1878. It has been the custom of 

 your newly elected President either to offer you a review of the progress of 

 science in New Zealand, to treat of some special branch of scientific 

 research, or to lay before you the results of his own investigations into the 

 zoology, geology, or ethnology of these interesting islands. 



With your permission, I shall follow the latter course, and venture to 

 offer you some remarks upon the geological features disclosed to us by the 

 piercing of the Christchurch and Lyttelton Eailway Tunnel, a gigantic 

 work, ever creditable to the energy and forethought of the Provincial 

 Government of Canterbury in those days when only a small population had 

 settled here, and the work to be undertaken was looked upon by many aa 

 far beyond our means. I shall preface the description of the tunnel, of 

 which a section on a scale of one inch to twenty feet hangs at the wall, by 

 some observations on the genetic history of Banks Peninsula, and upon the 

 remarkable system of dykes, by which the older caldera walls have been 

 intersected. 



When standing on the Canterbury plains the most striking feature in 

 the landscape is Banks Peninsula, rising so remarkably above the sea 

 horizon, that its regular form at once attracts our attention. First we 

 observe a series of mountains, of which the summits are all nearly of the 

 same altitude, which, as it appears to us, as far as our eye can follow their 

 outhnes, form nearly a circle, from which a great number of ridges slope 

 with a nearly uniform gradient towards south, west, and north. Above 

 them, in the centre, stands conspicuously a higher truncated mountain with 

 precipitous escarpments, assuming, accordiug to the position of the traveller, 

 a different aspect. The rim of the lower mountains in front rises to an 

 average height of 1,600 feet, whilst the central system attains an altitude of 

 3,050 feet. On reaching Banks Peninsula fi-om the sea, we find that several 



