488 R. W. ELLS — MIC.\ DEPOSITS OF THE OTTAWA DISTRICT. 



Mica Localities. — As regards the portions of the Laureiitian from which 

 mica may be obtained, it may be said that its occurrence in economic 

 quantities is now known at certain points over a very extended area. 

 Thus in Ontario the mines of Burgess and the adjacent townships yield 

 large quantities, generally of the phlogopite variety. Along the Ottawa 

 river it is found from a point nearly 100 miles west of Ottawa to the town- 

 ship of Grenville, 60 miles east of that city, while on the Gatineau river, 

 which flows into the Ottawa at the city of Ottawa, mines have been 

 located and worked for 80 miles north from its .mouth, and the mineral 

 is reported from points many miles further north along that stream. To 

 the east of Quebec it is known on the branch of the Saguenay called the 

 Manouan and in the townships of Escoumains, Bergeronnes* and Tadous- 

 sac, situated east of the mouth of that river, as well as at several other 

 places along the river Saint Lawrence. The mica found in this district 

 is chiefly muscovite. 



The principal areas where this mineral is at present worked are in the 

 belt which extends from North Burgess, in the province of Ontario, ap- 

 proximately along the strike of the gneiss, into the territory adjacent to 

 the Gatineau and Lievre. Over much of this area south of the Ottawa 

 river the Laurentian is concealed by the mantle of Cambro-Silurian rocks 

 belonging to the Ottawa River basin, but it may be said that the geologic 

 conditions and the stratigraphic sequence m the area south of the Ottawa 

 and in the rear of Kingston are the same as those found in the mineral- 

 bearing belts north of the Ottawa, and that the most favorable condi- 

 tions under which the deposits of mica and apatite may be looked for 

 occur in those areas occupied by the upi)er portion of the Laurentian, 

 where traces of igneous agency are visible in the presence of dikes of 

 pyroxene and quartz-felspar, though it should be stated that the mere 

 occurrence of these in the gneiss does not warrant the presence of either 

 of these minerals. 



