112 A. WINCHELL— A LAST WORD WITH THE HURONIAN. 



position of the Animike is now known in a dozen instances, but it is only- 

 justice to say that they were probably unknown to Irving.* 



It is claimed, however, that the superposition north of Gunflint lake was 

 known to Irving, but that he held the vertical schists here to belong to the 

 crystalline series. That he was wrong in this assumption appears from the 

 facts (a) that they have been traced again and again by the geologists of 

 the Minnesota survey, with unimportant interruptions, through East and 

 West Seagull lakes, Frog-rock lake, Kekequabic, Knife, Sucker, Basswood, 

 Fall, Long and Burntside lakes, to Vermilion lake and beyond, (h) While 

 these vertical schists on Gunflint lake are more crystalline than in many 

 other districts, especially about Knife lake and the Vermilion iron miues, 

 they are no more crystalline than the formation is on the eastern borders of 

 Vermilion lake, about Dike and Zeta lakes, on the long eastern arms of 

 Knife lake, along the southern shore of Sucker lake, and in many other 

 regions. 



2. The Animike is flat-lying, and the iron schists of Vermilion lake are 

 vertical ; yet Irving maintained that the iron schists are Animike. This 

 made it necessary to assume, gratuitously, that the iron schists are in shallow 

 folds, resting in a basin of older vertical schists. The impossibility of this 

 explanation is apparent (a) from the assumption which it makes of vertical 

 (iron) schists of later age, standing edgewise on the edges of schists of an 

 older age.f Here we encounter again the impossibility of conceiving how, 

 after the lower schists had been made vertical, the upper schists of later age 

 could have been placed vertically upon them. If it is pretended that the 

 upper schists are less vertical than the lower (as Irving's figures represent), 

 we contradict the facts of observation ; for they are vertical, and the lower 

 cannot be more so. The explanation is impossible also (b) because we find 

 the iron schists passing conformably in both directions across the strike, by 

 the well-known gradations, into those very crystalline schists which the 

 hypothesis supposes to be under them. 



3. The inapplicability of Irving's hypothesis appears from the fact that 

 the Animike, for six hundred miles east and west, is a formation compara- 

 tively earthy or non-crystalline, while the folded schists over the same dis- 

 tance are generally semi-crystalline. 



4. Its inapplicability is shown by all the evidence which precedes ; that 

 the material of the folded schists was laid down and the sheets tilted and 

 folded and denuded before the now flat-lying Animike was deposited. 



Professor Irving's assemblage of thirteen detached formations which, by 

 anybody, had ever been pronounced " Huronian," and his promulgation of 

 them to the world, under authority of the- United States Geological Survey, 



* Cf. A. Winahell, Some Results of Archfean Studies, Hull. Geol. Soc. Amer., vol. I, 1890, pp.C^e- 

 390, and the references there made, which need not be repeated here. 



•fSee his figure, Amer. Journ. 8ci., 3d ser.. vol, XXXIV, 1887, p. 259; also Seventh Ann. Rep. U. 

 S. Geol. Surv., 1885-'86, printed 1888, pp. 421, 434. 



