KfiSUME OF LITERATURE. 75 



shown by the fact that the Keweenawau beds along- the Mmnesota coast 

 are passed in descending order until the Animikie slates are reached at 

 Grand Portage Bay, but there is not a direct downward continuation of the 

 Keweenawan into the Animikie, for between the two there has been an 

 intervening period of erosion. This is shown by the fact that at Grrand 

 Portage Bay, where the two formations come together, the underlying slates 

 suddenly rise entirely across the horizon of 600 or 700 feet of the Kewee- 

 nawan sandstone. Also in northeastern Minnesota and in the Penokee 

 district the overlying Keweenawan is now in contact with one member of 

 the imderlying series and now with another. Further, in the Keweenawan 

 sandstones of Thunder Bay are found claert and jasper pebbles from the 

 Animikie, while in the Wisconsin Keweenawan are quartzite pebbles 

 apparently from the underlying' Huroniaii. 



Chester, A. H. The iron region of northern Minnesota: Eleventh Ann. Rept. 

 Geo], and Nat. Hist. Survey Minn., for 1882, 1884, pp. 154-167. 



This report g-ive-s in detail the result of two expeditions sent out, 

 the one in 1878, the other in 1880, by private parties for the purpose of 

 exploring the reported iron-ore deposits in the Mesabi iron range and on 

 Vermilion Lake. The earlier of these two expeditions paid little attention 

 to the Vermilion Lake deposits, and the following facts were obtained 

 chiefly as the result of the expedition in 1880. 



The prevailing rocks in the Vermilion Lake iron district are the slates 

 and schists and mica-schists and qiiartzite found in other Hurouian areas in 

 connection with iron-ore beds. The belt of iron ore is well defined. The 

 ore is found in connection with jasper and quartzite, and in many cases 

 with well-defined walls of slate. The ore deposits are intimately bedded 

 with the rocks of the country, slates, schists, and mica-schists and quartzite, 

 and stand nearly vertical, with perhaps a slight inclination to the south, 

 and trend generally east and west, though this varies from place to place. 

 The strata are much folded and contorted (p. 161). 



Exploration developed what seemed to be two principal deposits of 

 ore, running nearly east and west, and about a mile apart. The more 

 northern one, nearest the lake, has a total length of nearly a mile, lying in 

 sees. 28 and 27, T. 62 N., R 16 W. (p. 162). 



