Bell and Clarke. — Geological Eeconnaissance of Xbrtherrimost N .Z. 613 



Art. LXIL — A Geological Reconnaissance of Northernmost New Zealand. 

 By J. M. Bell and E, de C. Clarke. 



[Read before the Auckland Institute, 22nd November, 1909.] 



Introductory. 



Introduction. 



The northern portion of the North Auckland Peninsula is an area of both 

 geological and geographical interest. The sedimentary strata differ con- 

 siderably in lithological character, and also apparently in age. The igneous 

 rocks, while showing marked diversity in texture, mineralogical character, 

 and mode of origin, will probably be found to display a relatively close 

 similarity, in chemical composition. Several geographic cycles have passed 

 over this sea-bordered area, each leaving its mark on the land. 



The area may, for the sake of convenience, be called the Aupouri Pen- 

 insula, after the Maori tribe that formerly occupied it in considerable 

 numbers. 



A hm-ried reconnaissance of the Aupouri Peninsula made by us during 

 the spring of 1908 had as its chief object the obtaining of a general con- 

 ception of the main geological and geographical features for pm'poses of 

 comparison with those of the Whangaroa Subdivision, further south, where 

 detailed observations were at that time proceeding. The present paper 

 is to be considered as a very imperfect summary of the geology of northern- 

 most New Zealand. 



