Plate 8 



Upper hgure. Outcrop of ore (pyrite) zone, lower end of gorge at Pyrites. 

 The_ prominent lenticular mass in the foreground is a pegmatite dike, con- 

 taining pyrite, and occurring in the middle of an indefinite zone of sulphide 

 distribution about 25 feet thick. All the rock shown, however, belongs to 

 the rusty or pyritous gneiss formation. The slope at the left, facing north- 

 west, is close to the crest of a pitching anticline with west to west-northwest 

 axis. 



Right bank of Grass river, just above lower bridge at Pyrites. 



Lower figure. Structural dome in Grenville limestone, about 150 feet in 

 diameter. Adjoins overturned syncline of figure 7, which here occupies the 

 background. 



One and three-tenths miles northwest of Little River crossroads. 



