177 



the flow probably came from a crater situated near to and east- 

 ward of the point A. At the latter place there is an interesting 

 development, on the inner face of the wall of the Mount, of 

 ropy and stalactitic lava. 



In all the sections shown the rapid thinning out of the 

 lava, from the centre of the stream (50 ft. thick) towards 

 the sides, is clearly to be seen, and suggests quite a small 

 extension to the north and south. In well-sinking, in and 

 near the northern slopes of the Mount, the "blue rock" is 





^w* 



1& 





W'«mW,'""J*' 





BLUE 

 LAKE 



Sig^^.^ 1 



g//WiW0A»^ IH Tuffs, ift^i^^' 



Fig. 2. 

 Sketch plan and section to show the probable extent of 

 the lava flow. In the section the basalt is shown in black 



(not to scale). 



sometimes met with. From all the evidence available, the 

 maximum extent of this early flow is probably represented in 

 the above sketch (fig. 2). 



Mr. E. R. Stanley has carried out careful analyses and 

 microscopic examination of the lava, and also of the olivine- 

 bearing nodules, bombs, and fragments that occur throughout 

 the tuff deposits (Refs. 6 and 7). The following table 

 shows Mr. Stanley's analysis, compared with the average 



