55 



Miles and 

 Kilometres. 



190-5 m. Mine Centre.- — Altitude 1,190 ft. (363 m.) 

 306-5 km. From this point a trip is taken to the site of 

 the Golden Star mine on Bad Vermilion lake 

 to examine the following points: an occurrence 

 of limestone in the Keewatin series; the contacts 

 of the Seine series with the Keewatin, of the 

 Seine series with the Laurentian, of the Laur- 

 entian with the Keewatin, and of the anor- 

 thosite gabbro with the Keewatin ; and the litho- 

 logical characteristics of the rocks of the various 

 series. 



GEOLOGY OF THE VICINITY OF MINE CENTRE. 



GENERAL DESCRIPTION. 



The area to be visited has the typical physiography of 

 the southern part of the Pre-Cambrain terrane, and is 

 not essentially different from that of the Steeprock lake 

 area. Bad Vermilion lake is six miles (9-6 km.) long in 

 a direction a few degrees south of west, and follows in a 

 general way the strike of the Keewatin schists. It con- 

 tains comparatively clear water, and has depths of 400 feet 

 (122 m.) and over in places. The bold, glaciated rocks 

 on the southern shores stand out prominently. 



The general geology of the area is identical with that 

 of a great part of the region just passed through. The 

 particular interest attached to this locality is due to the 

 remarkably well exposed contacts which lie within 500 

 feet (152 m.) of the old mine. The geological succession, 

 in descending order, is : — 



Seine series. 



Unconformity. 

 Laurentian. 



Archaean -I Irruptive contact. 



Anorthosite (Keewatin?). 



Irruptive contact. 

 Keewatin. 



Keewatin. — Typical rocks of this series are well exposed 

 in the area, and consist of greenstone, green schist, diabase, 



