RELATIONS OF ANIMIKE AND KEWATIX SCHISTS. 



387 



from the east. This is a fact which I have ohserved, hut it is a local phe- 

 nomenon, and the normal flat-lying position is soon resumed.* I shall 

 therefore demonstrate that the Animike system is not one with the semi- 

 crystalline system. The nature of the observed contact on the north shore 

 of Gunfliut lake is illustrated in the accompanying diagrams, made on the 

 spot. Here are the two systems assumed by Irving to be identical, and to 

 have different dips in consequence of the remoteness from each other of the 

 portions compared (figs. 8, 9, 10). If you trust me for a correct statement 



G*lMiro,. 



Figure 10. — Observed Contact of Animike and Kewatin north shore of Gunflint Lake. 



of the facts you cannot regard the semi-crystalline schists and the uncrys- 

 talline schists as both Huronian.f 



I will here recall a diagram published by Professor Irving in an elaborate 

 memoir read before the National Academy of Science April 22, 1887, and 

 published in the American Journal of Science for September, October, and 

 November, 1887. The figure is given at page 261. % The first impression is 

 that he intended to represent the same state of things as I have shown. If 



SE Keweerreurr Series 



"Ve-vm-ilion 

 Trait. Series 



Ora.nl.Te. 



Figure 11. — Professor Irving's " generalized and partly idealized section of the northeastern part of 



Minnesota."}, 



so, one would suppose that he knew nothing of it by personal observation. 

 The interpretation shows that he misconceived his own figure. The verti- 



* Compare Seventeenth Annual Report Minnesota, 1888, p. 47 



Jour. Sei., Oct., 1887, 3d Ser., Vol. xxxiv, p. 314— the communication being dated Aug. 2<), 1887. 



JThe figure and the entire exposition of the relations of the Animike and the older schists are. 

 reproduced in the "Seventh Annual Report of the Director" of the U. S. Geological Survey, 1885- 

 1886. Printed 1888; received April 23, 1889. 



§ This is his "generalized " illustration, and is here chosen because, in addition to the uncon- 

 formity, it explains Professor Irving's theory (or hypothesis) respecting the way in which the 

 Vermilion iron ores exist in the Animike. 



