276 Canadian Record of Science. 



analysis, which was done in duplicate. A thin section from 

 the specimen when examined under the microscope, shows it 

 to consist of analcite and orthoclase fragments about 3 mm. in 

 diameter, together with three or four prisms of aegirite augite 

 about 1 mm. long. The finer grained matrix consists of a 

 mixture of orthoclase, analcite, aegirite-augite and small frag- 

 ments of garnet. Orthoclase makes up the greater part of 

 this matrix. The particular slide examined showed analcite 

 to be in excess of orthoclase ; but judging from the relative 

 amounts of alkalies as given in Dr. Dickson's analysis, column 

 II, table II, it seems that the specimen as a whole contains 

 excess of orthoclase. 



Table Mo. II. 





I 



II 



IIa. 



III 



SiO, 



47.82 



54-95 



.916 



52-83 



ALA 



J3-5 6 



18.64 



.182 



20.70 



Fe A 



4-73 



4-75 



.029 



2.84 



FeC) 



4-54 



i-55 



.02 1 



1. 19 



MgO 



7-49 



0.60 



.015 



.41 



CaO 



8.91 



2.27 



.04T 



1. 00 



Na.,0 



4-37 



4.91 



.079 



9-94 



K 2 



3-23 



7-6 5 



.081 



4.87 



H. 2 + 



3-37 



3-35 



.185 



5.28 



H 2 0- 





0.90 





•37 



Ti0 2 



0.67 



0.42 



.005 



0.16 



P A 



1. 10 



0.18 



.001 



0.03 



CI 



0.04 







0.06 



Mn 



Trace 



°-34 



.C05 





Ba 



0.16 









SrO 



0.21 











100.20 



100.51 





99.62 



I. Analcite basalt from dike on east side of Highwood Gap. 

 H. W. Foote, analyst. 1 



II. Analcite-trachyte-tuff from a point some six miles south 

 of the town of Blairmore which is situated on the Crows 

 Nest branch of the Canadian Pacific Railway. The specimen 



1. Igneous rocks, Highwood Mountains, Mont. L. V. Pirsson, Bull. 

 No. 237 U. S. Geol. Sur. 1905. 



