Cnawronp.— Geology of the North Island of New Zealand. 311 
northward, over Waiheke and Kawau to the Bay of Islands. In a southerly 
direction they extend, through Hakarimata and Hauturu range, parallel 
with the West Coast, to the Mokau district, where, at Wairere, the Makau 
River falls in a magnificent cascade over a lofty precipice of that rock.” 
“The same formation occurs again in the Rangitoto Mountain, in the 
upper Waipa, and west of Taupo Lake, in the Tuhua mountains.” 
To the southward of the country described by Hochstetter, palmozoie 
slates and sandstones are found cropping out in the bed of the Waipare, a 
tributary of the upper Whanganui, and from Maori report old slates will 
probably be found in a similar manner in the bed of the Whakapapa and 
other tributaries of the Whanganui, and perhaps also at some point of the 
upper part of the main stream itself. 
At the Waipare, tertiary sandstones and voleanie tuffs have been cut 
through by the action of the stream down to the paleozoic base. The latter 
rock, at this point, is a slate traversed by threads of quartz. 
To the eastward of the Hauraki Gulf the palæozoic rocks retain somewhat, 
but in a lesser degree, the bold angular form of the main ranges to the 
eastward of the island; but on the western side of the gulf, as at Kawau, 
they frequently sink to comparatively a few feet above the sea level, and are 
often covered by a thin coating of newer tertiaries, by which their charac- 
teristic outline is destroyed. 
SECONDARY, OR Mesozoic FORMATIONS. 
It is quite possible that secondary rocks may exist to a considerable 
extent in the North Island; but, if so, they must be in great part either 
covered up and hidden by rocks of a later era, or be represented by some 
of the rocks now classed as paleozoic. To Hochstetter belongs the merit of 
discovering the only decided secondary rocks which have yet been found, 
and the following is his description of them* :— 
“A very wide interval occurs between the primary rocks of the North 
Island and the next sedimentary strata that I met with. Not only the upper 
members of the primary series are absent, but also nearly the whole cf the 
secondary formations. The only instance of secondary strata that I have 
met with consists of very regular and highly inclined beds of marl, alter- 
nating with micaceous sandstone, extending to a thickness of more than 
1,000 feet, which I first saw on the South Head of the Waikato, and after- 
wards met with on the western shore of Kawhia Harbour. 
“These rocks possess great interest, from the fact that they contain 
remarkable specimens of marine fossils, which belong exclusively to the 
secondary period; especially Cephalopods of the genera Ammonites and 
* Fischer's Translation, p. 17. 
