158 



THE VERMILION IRON-BEARING DISTRICT. 



a manuscript map by Irving this belt of schists is otithned. Special 

 attention has been called to them by both A. and N. H. Winchell in 

 tlieir published reports. The earliest explanation offered was that of 

 A. Winchell, " who studied the good exposures of these schists upon Burnt- 

 side Lake and there found them, as has been described, permeated by the 

 oranite. Figs. 1 and 2, from his report, illustrate the occurrence. His 

 conclusion was that they were derived from graywackes by metamorphism." 



Fig. 1.— Eeproduction of sketch by A. Winchell, showing the intricate relationship between the granite of Burntside Lake 



and the amphibole-schists. 



N. H. Winchell " refers to this belt of schists, and concludes that they 

 have been "produced by the granitic intrusions or by the force which 

 accompanied them," and that when acid clastic rocks Avere affected the 

 mica-schists were produced, and when the basic greenstone Avas involved 

 the amphibole-schists were produced. To these rocks Winchell applied 

 the name Coutchiching, using it in the sense proposed by Lawson.'^ In his 



«Geol. and Nat. Hist. Survej' of Minnesota, Fifteenth Ann. Rept., 1887, pp. 40^1. 



bGeo\. and Nat. Hist. Survey of Minnesota, Fifteenth Ann. Kept., 1887, pp. 172-178. Geol. and 

 Nat. Hist. Survey of Minnesota, Final Kept., Vol. IV, 1899, p. 246. 



cGeol. and Nat. Hist. Survey of Minnesota, Final Eept., Vol. IV, 1899, pp. 272, 273, and 283. 



f'Eeport on the geology of the Rainy Lake region: Geol. and Nat. Hist. Survey of Canada, 1889, 

 F. pp. 21-35 et seq. Geology of the Rainy Lake region: Am. Jour. Sci., 3d series, Vol. XXXIII, 

 1887, p. 477. 



