32 
THE GEOLOGY OE ATJCKLAKI). 
stretches in a more northerly direction to the .Last Coast, 
between Maketu and Tauranga, the farthest extremities of 
which reach even to the Auckland District. On one side ot 
Hauraki Gulf, the Coromandel range is covered with tracliytic 
breccia, and again, on the West Coast, the same rock forms the coast- 
range from Manukciu to Kaipara. This extensive plateau is 
intersected by many deep valleys, the sides of which are 
characterised by a succession of remarkable terraces. The same 
plateau is also broken in many places by more or less regular 
trachytic cones from 1000 to 3000 feet high. That you may 
become acquainted with the geological character of such moun¬ 
tains, I will mention several examples, the names of which are 
well known amongst European settlers. To this class of moun¬ 
tains belong Karioi on the "West Coast, near Wliaingai oa, 
Pirongia on the Waipa, the regular cone of JvcikcpuJiii between 
the Waipa and the Waikato, Mciungatautari on the Waikato, 
Aroha on the Waihou, Piitauaki or Mount Edgecombe on the 
East Coast, and many others. The only active mountain which 
belongs to this class is Whakari or White Island, in the Bay of 
Plenty, a solfatara like the active crater of Tongariro. 
Mr. David Burn, in his account of “ A Trip to the East 
Cape,” says :— 
“ In about an hour after passing Elat Island, the snowy 
vapour upon White Island began to be discernible. By 1 p.m. 
we were in immediate contiguity with this remarkable island, 
passing quite close to its southern extremity. As we made our 
gradual approach, its aspect was of the most singular description. 
Except on its northern point, to which the sulphurous vapour 
does not seem to reach, it is utterly destitute of vegetation ; 
there are patches of growing underwood ; but in every other 
direction, the island is bald, bleak, and furrowed into countless 
deep-worn ravines. After we had passed it a short distance to 
the eastward, the capacious basin of the crater, with its nume¬ 
rous geysers roaring and raging, exposed its sulphurous bosom 
to our eyes and nostrils. If the outer and western sides of 
White Island be blank and furrowed, its inner circle is chased, 
as it were, in a rare and picturesque manner—the sides of the 
hills, from their lofty mountain summits to the base, being 
