[ADAMS 4 barlow] ALKALI SYENITES OF EASTERN ONTARIO 67 



Owing to the large percentage of corundum present, the rock is a 

 very peculiar and unusual one, and represents a new sub-class, order, 

 rang and sub-rang in the Quantitative Classification. We accordingly 

 propose the following names for the new order and rang, and the name 

 Dungannonite for the rock itself : 



Class I Persalane 



Sub-class II (Section I) Dosalone 



Order 5 Indare 



Rang 3 Dungannonase 



Sub-rang 4 Dungannonose 



An analysis of the andesine occurring in the rock was made by Mr. 

 M. P. Connor, B. Sc. This is given under I. Tine material for the 

 analysis was obtained by separating the feldspar with Thoulet's solution. 

 It was somewhat impure, owing mainly to the admixture of a small 

 amount of biotite. This accounts for the iron, potash and magnesia 

 found in the analysis. Neglecting these, the composition corresponds 

 rather closely to that of an andesine with the formula AbsAng. The 

 specific gravity of a feldspar with this formula should be 2.68, while 

 that cf the andesine separated from the rock was 3.668. For 

 purpc^îes of comparison the theoretical composition of andesine cor- 

 n spending with the generally accepted formula for plagioclase with the 

 i-atio of the soda to the lime of 1 :1 (AboAnJ is given imder II, while 

 under III the composition of andesine made up of albite and anorthite 

 in the ratio of 3 :2 is shown. 



I II III 



SiOa 57.15 69.84 58.11 



AI2O3 26.74 25.46 26.62 



FesOg+FeO .... 0.25 



MnO trace 



CaO 6.66 6.97 8.34 



MgO 0.59 



K2O 0.38 



Na,0 6.83 7.73 6.93 



Loss of ignition. . 0.90 



99.50 100.00 100.00 



Specify gravity .... 2.668 2.671 2.680 



