AND GEOLOGY OF THE COLUMBIA. 107 



HoRNBLENDIC GrNElS!^. — Macroscopic. — A specimen from a boulder at Freuclitowu is 

 of medium giaiu, rather dark grey, aud slightly schistose iu appearance. 



Microscopic. — It consists of quartz with fluid cavities containing salt cultes ; much 

 orthoclase, some of it miiroperthitic, with trichites and other inclusions, much horn- 

 blende of dark green and yellow tones, and a little brown biotite. Apatite and magnetite 

 are found in small civxantities, and epidote is a decomposition product. 



Granite. — Macroscopic. — Several specimens of granite were obtained from boulders 

 at French Creek aud at points on the trail between Laporte and Eevelstoke. They are 

 light grey, medium to coarse-grained rocks, often porphyritic, containing oblong white 

 cross sections of felspar sometimes an inch in length. The smaller felspars are yellowish' 

 white and more weathered than the larger ones. 



Microscopic. — Quartz of the kind iisnal in granite is abundant ; also orthoclase, 

 where not replaced by microcline, which is often the case. Microperthite and plagio- 

 clase are less important. The porphyritic crystals are of microcline, so far as observed. 

 Biotite and hornblende occur in considerable amounts, replacing one another. Apatite 

 is frequent, and epidote, the latter a product of decomposition. 



(T.) Roger's Pass (C. P. R.) 



Mica Schist. — Macroscopic. — The mica-schists are chiefly white or light grey, con- 

 sisting of quartz and muscovite. They sometimes aj)proach the qnartzites from the small 

 quantity of mica they contain. A distinct variety, dark iron grey, with metallic lustre, 

 occurs at Albert Canyon on the Illicillewaet. 



Microscopic. — The quartz has often a clastic appearance. The colorless muscovite is 

 of the usual kind, not sericite. No chlorite has been observed in my specimens, which 

 however are only three in number, excluding the rock from Albert Canyon. The last 

 mentioned rock gets its black color from the large number of dark, amorphous looking 

 particles it contains in addition to quartz and mica. That the black substance is carbon, 

 or some carbon compound, is proved by the fact that a fragment readily burns white iu 

 the blowpipe flame ; and the gases formed, when it is heated in a glass tube in a current 

 of oxygen, give with limewatcr a milky precipitate, which is re-dissolved by continued 

 passage of the gas. 



GrNEiss. — Macroscopic. — The two specimens iu my collection (one from the " summit " 

 of the pass) are fine grained, very light colored, and not very schistose. They are far 

 from typical specimens as compared with Laurentian gneiss from Ontario. 



Microscopic. — They contain quartz, some orthoclase and microcline, and plagioclase ; 

 also a little microperthite, and biotite and muscovite in small quantities. 



Ill . — Conclusion. 



An attempt has been made iu the first part of this paper to give by brief descrip- 

 tions some idea of parts of the Selkirks not easily reached from the railway, and hence 

 rarely visited. When the region has been rendered more accessible by means of trails 



