﻿294 Canadian Record of Science. 



a richly mineralized district. In the study of the 

 characteristic rocks of this district the writers were much 

 aided by the kindness of Dr. F. I). Adams, of McGill 

 University, to whom they are indebted for the microsco- 

 pical examination of a number of rock sections and as 

 well as for suggestions upon the nature and origin of 

 various specimens sent to him. 



The country rock of this district is a granite. It is 

 bounded to the north, some six miles above Ten Mile 

 Creek, by the Slocan Slates of McConnell, in which occur 

 the rich silver-lead mines now being so extensively and 

 profitably worked. 



To the west there is a contact with a great region 

 of gneissoid rocks and dark schists, which, for the most 

 part, lie west of the great trough formed by Slocan Lake 

 and Slocan Eiver, but which also cross over to the east 

 side of the Lake at a point somewhat south of Twelve 

 Mile Creek, and continue along the east shore, at least, 

 until Springer Creek is reached, and probably occur along 

 the lower slopes of the mountains further south. To the 

 south and east the characteristic granite continues 

 towards Kootenay Lake and the western arm of Kootenay 

 Lake. 



The contact of the gneissoid rocks with the mineral- 

 bearing granites to the east of it is not well defined, 

 excepting the fact that the block of gneiss and schists 

 which lies east of the Lake forms a low bench, and 

 the hills which rise above this bench are of a different 

 nature and are well mineralized, which cannot be said of 

 any portion of the gneisses so far prospected. 



Between the gneiss and the granite proper, however, 

 there usually intervenes a wide band of a highly silicious 

 somewhat cleavable rock, which may possibly be a felsite. 

 This band is mineralized, but is considerably broken. 



With the exception of a few isolated patches of a 

 highly silicious metamorphic rock of a dark color, the 



