[ADAMS 4 barlow] ALKALI SYENITES OF EASTERN ONTARIO 61 



This gives the rock the following position in the quantitative classi- 

 fication : — 



Class I Persalane. 



Order VII Tasmanare (near Ontarare). 



Rang I Laugenase. 



Sub-rang II Craigmontose. 



It is a new type for which we propose the name Craigmontose 

 (Craigmontite). The mode or actual mineralogical composition of the 

 rock is somewhat different from the norm as given above. It is as 

 follows : — 



Nepheline 63.18 



Oligoclase 29.66 



Muscovite 4.39 



Calcite 1.42 



Corundum .50 



Biotite .50 



Magnetite .10 



99.75 



Corundum-hearing nepheline syenite {poor in nepheline). — An 

 analysis of the second phase of the nepheline syenite, namely that rich 

 in plagioclase and corundum, but containmg less nepheline than that 

 just described, was also made by Mr. M. F. Connor, B.Sc, and was found 

 to have the following composition : — 



Corundum (determined separately) . . 4.45 



SiOs 55.45 



TiO^ 0.30 



AlA 21.65 



Fe,03 0.81 



FeO 0.49 



MnO 0.01 



CaO 3.65 



MgO 0.13 



K,0 1.62 



Na,0 9.31 



PÂ 0.01 



CO, 0.88 



H^O 1.64 



100.40 



