1855.] C. FORBES — NEW ZEALAND. 527 



already described at the foot of Mount Grey, prove that a consider- 

 able elevation of the land has taken place, and that a very slight 

 depression vrould again convert the peninsula into an island. 



From the peninsula to Otago the plains extend almost in an un- 

 interrupted level. Breaking gradually into undulating hills, they 

 terminate in the slaty district of Otago. The coast-line of this 

 district has been examined by Mr. Walter Mantell*. 



The rocks found along the harbour of Otago are porphyries, traps 

 of various kinds, hornblende-rock, and yellow clay-schist ; the de- 

 composition of the latter rock forms the substratum of the super- 

 ficial vegetable mould. Inland there is an open country, composed 

 at first of undulating hills, covered with fern and grass, terminating 

 in a series of grassy plains, which, running between lofty hills, pre- 

 sent the appearance of having at one time been arms of the sea. On 

 a hill overlooking the first of these plains there is a lignitic deposit, 

 at a considerable elevation, and showing itself on both sides of the 

 hill ; it appears to be almost horizontal, and is overlaid by quartz- 

 gravel, pebbles of which are also imbedded in the lignite. This 

 lignite is supposed to have some connexion with the coal found at 

 the Molyneux River, sixty miles to the south ; but no opportunity 

 occurred to investigate this point. 



Sandstones underlie the lignitic deposit ; shales, clay, and quartz- 

 gravel cover it. Twenty miles to the south, slates, traps, and shelly 

 limestones are found. In the immediate neighbourhood a schistose 

 rock is found in detached masses on the hill-side. 



A broken undulating country extends from this point to Jacob's 

 River, already alluded to ; the rocks entering into its formation have 

 not been examined. 



North Island. — The North Island of New Zealand, in its geological 

 formation, differs considerably from the Middle and South Islands. 

 It is the centre of both extinct and active volcanic agency. To the 

 north, in the neighbourhood of Auckland, volcanic hills with perfect 

 craters abound, the face of the country is covered with scoriae, and 

 evidence of elevation of the land exists. 



The Great Barrier and Kau-wow Islands are rich in copper. 

 Metamorphic rocks, trap, and conglomerate are the prevailing rocks. 

 In the centre of the Island, active volcanic action exists ; hot lakes 

 and springs are numerous, and earthquakes frequent. 



The coast-line of the north side of Cook's Straits is chiefly com- 

 posed of metamorphic clay -slate, but there are also traps ; and at 

 Cape Palliser there are said to be fossils 200 feet above the present 

 sea-level. The tertiary blue clay with shells is also found in this 

 island, and appears to extend from Wanganni to the Waidrop Plain, 

 in a south-east direction; the shells are identical with those of the 

 Middle Island. 



The coal found at Waikato is of a very inferior quality, and of 

 much the same character as the Massacre Bay coal. (For parti- 

 culars of its combustion see further on, p. 529.) 



* Quart. Journ. Geol. Soc. vol. vi. p. 319, &c. 



