so ROYAL SOCIETY OF CANADA 



is intergrown with that just mentioned, and presents, absorption colours 

 ranging from deep lavender blue to light green, Biotite is present iu 

 insignificant amount. 



The syenite pliase of tliis rock is red in colour and composed almost 

 exclusively of feldspar, wliicli is for the most part micropcrthite, the 

 iron-magnesian constituent occurring in occasional dashes with a rudely 

 parallel arrangement. It ditl'ers from the granite, not only in the fact 

 that no quartz is visible in the sections, but also in the absence of horn- 

 blende. The rock contains a small amount of biotite, while a little mos- 

 covite and calcite are also present. The latter may be secondary. The 

 s(Tda feldspar preponderates over the potash feldspar, as shown by the 

 analysis given ibelow. 



An analysis of this rock was made by Prof. Norton-Evans, with 

 the following result : — 



SiO., 64.15 per cent. 



AU), 19.04 



FeA 1.02 



Feb .93 



MnO .16 



CaO 1.37 



MgO .37 



K.0 7.10 



Na./) 5.37 



P^O, .10 



CO, .70 



H.,0 .27 



100.58 



If the norm of this rock be calculated, it will be found to be as 



follows. The 

 omitted. 



calcite is considered to be secondary and is therefore 



Quartz 1.86 



Orthoclase 42.26 



Albite 45.59 



Anorthite 5.84 



Corun(hnn .30 



Hvpersthene 2.09 



Magnetite 1.39 



Apatite .34 



pe 



r cent 



99.67 



