Geology.] 



SUBANTARCTIC ISLANDS OF NEW ZEALAND. 



695 



SiOo 



Al,6, 



Fe,0., 



FeO 



CaO 



MgO 



TiO., 



Na,b 



K.,6 



h;o 



Analysis. 



65-52 

 14-80 

 5-72 

 2-83 

 1-10 

 0-16 

 0-56 

 4-92 

 3-23 

 1-76 



100-60 



This result shows that the rock approaches closely to the trachytes, but structurally 

 as well as mineralogically it differs considerably irom the other trachytes of Campbell 

 Island. 



The only locality at which this rock was found was on the eastern shore of 

 Perseverance Harbour, about a mile from the observatory-site, in a locality where 

 practically all the other rock exposures are covered by slip -material which has 

 come down the flanks of Mount Honey. 



Fig. 12. — ^ficuo. Section of Basalt Dyke fi'.oii Dyke 9, 

 OF Perseveuance HAKBouit, Campbell Island. 



Feldspar and angite in about equal proportions, and 

 titaniferous iron-ore. 



Head Fig. 13. — Micro. Section of Lijiestone, North-west Bay, 



Campbell Island. 



Nodosaria at the left of the figure. 



Basalts. (Figs. 9 and 12.) 



There is a considerable amount of variety in the basaltic rocks, though the 

 variation is more a matter of structure than of mineral content. The basalts are 

 all black rocks, and those which are found at the high levels are usually much more 

 fine-grained than those at the lower levels. At the top of Mount Dumas and Mount 

 Honey an extremely dense rock constitutes a lava-flow. The feldspar is in very 



