THE OTTAWA f(ATURALIST. 



Vol. XVII. OTTAWA, AUGUST, 1903. No. 5. 



PETROGRAPHY OF SOME IGNEOUS ROCKS OF THE 

 KETTLE RIVER MINING DIVISION, B.C. 



L. P. Silver, B. Sc, Petrographical Laboratory, McGill University, 



Montreal. 



The district from which the following specimens were col- 

 lected is a comparatively new mining locality, situated between 

 lat. 49" and 50' and long. 118 and 119 . 



The specimens were collected by Mr. W. F. Robertson, Pro- 

 vincial Mineralogist of British Columbia, and sent to Dr. Frank 

 D. Adams, Professor of Geology at McGill University, who in- 

 tended to make a microscopical examination of them. As, how- 

 ever, the writer was working in the Petrographical Laboratory of 

 McGill University at the time, Dr. Adams kindly consented to 

 hand them over to him, and the following descriptions have been 

 written with Dr. Adams's help and under hi-j supervision. 



As no petrographical work has hitherto been done in connec- 

 tion with this district, the writer decided to publish his observa- 

 tions, hoping they may be of interest as descriptions of rocks 

 immediatel> connected with ore deposits of what may prove to 

 be an important mining region. 



The sentences between inverted commas are quotations from 

 Mr. Robertson's notes on the respective occurrences. These, 

 together with the descriptions of localities, are taken from his 

 report on the district, which appeared in the Annual Report of the 

 Bureau of Mines of British Columbia for the year 1901. The 

 numbers are taken from Mr. Robertson's specimens. 



Numbers 117. 120, 138, 125 were all collected from Aspen 

 Grove. 



