april — sept. 1859.] the Province of Auckland. 123 



Origin. 



Plutonic and 

 Metamorphic rocks . . . « 



Diagram. 

 Age. 



Organic Remains. 



Volcanic 



Aqueous, 



Primitive 



formation. 



Primary. 



Secondary. 



Tertiary. 



Quartary. 



Tr achy tic. 



Basaltic. 



! 



Fossiliferous. 



No fossils. 



No fossils. 



With these preliminary remarks, I now proceed to the main sub- 

 ject of my lecture. 



The first striking characteristic of the Geology of this Province 

 — and probably of the whole of the Northern Island of New 

 Zealand — is the absence of the primitive, plutonic, and metamorphic 

 formations, as granite, gneiss, mica-slate, and the like. I have been 

 informed by Mr. Heaphy, that these rocks are of wide-spread ex- 

 tent in the Middle Island, forming mountain ranges of great alti- 

 tude, covered with perpetual snow, and reaching in Mount Cook 

 probably to 13,000 feet. The rocks of these formations contain 

 the principal metallic riches of the earth. Therefore we cannot 

 hope to find these riches developed in the highest degree in the 

 Northern Island ; but as other formations also contain metalli- 

 ferous veins, there may be found many mines worth working in 

 the rocks I am about to describe. 



The oldest rock I have met with in the Province of Auckland 

 belongs to the primary formation. It is of very variable charac- 

 ter — sometimes being more argillaceous, of a dark blue colour, 

 (when decomposed, yellowish brown, the colour generally present- 

 ed on the surface,) and more or less distinctly stratified like clay- 

 slate — at Maraitai on the Waitemata) ; at other times the siliceous 

 element preponderates, and, from the admixture of oxide of iron, 

 the rock has a red, jasper-like appearance — (at Waiheki, Manga- 

 nese Point.) In other localities it is more distinctly arenaceous, 

 resembling the old Sandstones of the Silurian and Devonian Sys- 

 tems, called Grauwacke — (at Taupo, on the Hauraki Gulf.) 



As no fossils have yet been found in this formation in New Zea- 



Geology oe the Province oe Auckland. 



I. — Primary Formation. 



