72 THE VERMILION IRON-BEARING DISTRICT. 



(p. 81). The Knife Lake cliloritic or serpentinous quartzite is regarded as 

 Huronian (p. 86). 



On the south side of Vermilion Lake are beds of jasper and iron 

 hematite which are regarded as the equivalent of the Gunflint beds. These 

 are conformable with the raagnesian schists and slates which are in a 

 vertical attitude. They pass down into the schists, and in places the 

 schists and schistose structure penetrate the jasper and iron (pp. 103-4). 



WiNCHELL, N. H. The Cupriferous series in Minnesota: Proc. Am. Assoc. 

 Adv. Sci., Twenty-ninth Meeting, 1880, pp. 422-425; Ninth Ann. Rept. Geol. and 

 Nat. Hist. Survey Minn., for 1880, 1881, pp. 385-387. 



In this description of the Copper-bearing series the impression is made 

 that the series gradually becomes more and more changed and crystalline 

 as one goes away from the shore of Lake Superior. The following 

 relations are mentioned: 



The tilted red shales, conglomerates, and sandstones at Fond du Lac .... 

 are the same as those associated with the igneous rock all along the shore. They 

 lie there on a white quartz pebbty conglomerate of a few feet in thickness, which 

 lies unconformablj" on the roofing slates of the Huronian, the same formation 

 which succeeds to the red-rock formation .... at Ogishke Muncie and Knife 

 lakes, northwest of Grand Marais' [p. 387]. 



1S82. 



WiNCHELL, N. H. Preliminary list of rocks: Tenth Ann. Rept. Geol. and 

 Nat. Hist. Survey Minn., for 1881, 1882, pp. 9-122. 



In this report the publication of Winchell's field notes is continued. 

 From them we learn that the flint and jasper formations of Gu.nflint Lake 

 appear to be in apparent unconformit}'' with the underlying slates and 

 syenites (p. 88). On Ogishkie Muncie Lake is found a great conglomerate. 



The conglomerate . . . contains large rounded pieces of the "Saganaga 

 granite," which proves the greater age of that granite and the unconformability 

 of this slaty conglomerate. . . . The conglomerate also here contains red jasper 

 [p. 93]. 



The descending succession in northeastern Minnesota is given as 

 follows : 



(1) The nearly horizontal quartzites and slate. ... (2) The coarse grit 

 or fine conglomerate. (3) The jasper}'- and calcareous . . . Gunflint beds, (i) 

 Gray marble. (5) The tilted, slatj^ conglomerate, and the great conglomerate 



