94 THE VERMILION IRON-BEARING DISTRICT. 



WiNCHELL, Alex. Conglomerates enclosed in gneissic terranes: Am. Geologist, 

 Vol. Ill, 1889, pp. 163-165, 256-262. 



Ill this paper Alexander Wiiicliell restates his conclusions concerning the 

 origin of the Saganaga (Sixteenth Ann. Rept., p. 2 19) and Sea-Gull (Sixteenth 

 Ann. Rept., p. 298) syenite conglomerate. He maintains in this paper that 

 the conglomerate is produced from a fragmental rock by selective meta^ 

 morphism, the completely crystalline gneissoid rocks retaining rounded 

 fragments which are residual clastic material. The conglomerate of Wonder 

 Island is not one consisting originally of a mass of pebbles, over which a 

 fluid magma has been poured, for the pebbles are not in contact; they 

 could not have lain where they are before the magma existed. The gneissic 

 magma was contemporaneous with the pebbles, and supported them and 

 prevented their contact. The magma must have been plastic, but it was 

 low-temperature igneo-aqueous plasticity. 



WiNCHELL, N. H. Some thoughts on eruptive rocks, with special reference to 

 those of Minnesota: Proc. Am. Assoc. Adv. Sci., Thirty-seventh Meeting, 1889, pp. 

 212-221. 



N. H. Winchell, in 1889, in a general discussion of the origin of the 

 eruptive rocks, maintains that there are four epochs of basic eruption in 

 Minnesota: First, that represented by the crystalline schists of the Vermilion 

 group ; second, an epoch succeeding the gray wackes of the Keewatin and 

 forming a part of the Keewatin; third, one succeeding the Animikie, during 

 which the Great gabbro or Mesabi overflow was outpoured. 



1S90. 



Report of the Ro3'al Commission on the Mineral Resources of Ontario and 

 Measures for their Development. Toronto, 1890, pp. 123-126. 



In this report there is a brief description of observations made by three 

 members of the commission who visited the Vermilion district. No state- 

 ments of geologic character wliich are of any interest are given. State- 

 ments were gathered from miners and prosf^'^tors which show that promising 

 iron-bearing formations exist in Ontario in the northeastern extension of the 

 Vermilion iron range. 



WiNCHELL, N. H. and H. V. On a possible chemical origin of the iron ores 

 of the Keewatin in Minnesota: Am. Geologist, Vol. IV, 1890, pp. 291-300, 382-386; 

 also Proc. Am. Assoc. Adv. Sci., Thirty-eighth Meeting, 1890, pp. 235-242. 



