328 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 27, 



coast traversed by the exploring party, with examples of the rocks 

 and strata exposed in the low cliffs in the various localities men- 

 tioned in the report. 



By far the greater part belong to plutonic, volcanic, and metamor- 

 phic rocks : the unaltered sedimentary deposits are hmited to the 

 limestones of Ototara and Anaamatara, the argillaceous strata of 

 Onekakara and Kakaunui, and the newer beds of aggregated iron- 

 sand and sandstone containing recent species of shells. Of the igneous 

 products, the most abundant are obsidian (called by the natives tu- 

 hud), basalt, and many varieties of amygdaloids ; some of these could 

 not be distinguished from the toadstones of Matlock and Crich Hill, 

 in Derbyshire. Nephrite or jade {ponamu of the New Zealanders), 

 gneiss, serpentine, greenstone, chlorite slate, micaceous schist, sili- 

 ceous slate, clay-slate, &c. There are no specimens of granite. 



Sulphate of barytes, compact zeolite, and garnets ; many varieties 

 of chalcedony, agates, quartz, and jasper ; some masses resemble the 

 green or chlorite jasper of India ; semi-opal, onyx, &c. There are 

 no examples of any of the ores of tin or copper. Of iron, there are 

 clays largely charged with oxide, sulphuret, and phosphate. Titani- 

 ferous iron {menaccanite) forms, with crystals of augite, extensive 

 beds of sand on the shore of the North Island, near New Plymouth, 

 &c. This sand constitutes the bed in which the bones of the Moa, 

 &c. occur, near the embouchure of the Waingongoro, as mentioned 

 in my former Memoir. 



To this list may be added a fine white rock, resembling the meer- 

 schaum-stone, and consisting of carbonate of magnesia. 



A very hard conglomerate of small pebbles of variously coloured 

 quartz, jade, &c., cemented together by a ferruginous paste, is worthy 

 of remark, from its close resemblance to the matrix in which diamonds 

 occasionally occur in some parts of the Brazils. 



K few fragments of lignite, and of bituminous wood, are the only 

 indications of fossil fuel : no true coal, nor strata that are carboni- 

 ferous in other countries, were observed in any part of the island 

 comprised in the present notice. 



Sedimentary Deposits and Organic Remains. 



Ototara Limestone. 



Of the stratified fossiliferous deposits, the most ancient is the lime- 

 stone which stretches from near Morokura to beyond Anaamatara, 

 and within five miles of Kakaunui. From the general lithological 

 resemblance of this rock to the coralline cretaceous deposits of Faxoe 

 and of Maestricht, and the presence of terebratulse, sharks' teeth, 

 echinites and spines, and fossils allied to the belemnite, the geologist 

 might naturally conclude that the Ototara strata are referable to 

 the chalk formation, and may be regarded as the equivalents of 

 certain upper beds of the series. The microscopical examination 

 would still further strengthen this idea, the Foraminifera of which 

 the calcareous cement is almost wholly made up, belonging to those 

 forms which prevail in the English chalk ; even the soft bodies of 



