SOUDAN FORMATION. 215 



Prospectors were busy in the years prior to tlie opening of the raih-oad 

 in prospecting the range to the east of Tower, and in 1883 outcrops of ore 

 were found by Mr. H. E. Harvey in sec. 27, T. 63 N., R. 12 W. The 

 body of iron ore indicated by these outcrops was fiu-ther tested in 1885-86 

 and- led to the opening up of the great deposits at Ely on which are now 

 •working the Chandler, Pioneer, Zenith, Sibley, and Savoy mines. During 

 1888 there were shipped from the Chandler mine 54,612 tons of high- 

 grade ore. 



From this time on the development of the range was rapid, as is shown 

 by the annual increase in the shipments of ore (pp. 242-243). 



ORE HORIZONS. 



The iron-ore deposits of the Vermilion district show a striking analogy 

 with those of the Marquette district. Like them, they may occur in two 

 positions with respect to the iron-bearing formation. They are found, first, 

 at the bottom of this formation and, second, within it, the ores in both 

 cases being the same in character. The ores occurring at the bottom of 

 the iron formation rest immediately upon the Ely greenstone, which thus 

 forms the foot wall, and are overlain by and grade iip into the jasper and 

 associated rocks of the iron-bearing formation, which usually forms the 

 hanging Avail. Ores occurring within the formation either rest upon some 

 impervious part of the formation above its base or else lie in the midst of 

 the iron-bearing rocks, their position being determined by certain factors 

 which will be discussed below. Workable ore deposits are known at two 

 localities — Soudan and El)'. At Soudan there are a number of deposits 

 belonging together, so far as mode of occurrence is concerned, and they 

 are worked through a number of shafts, all belonging to the Minnesota 

 Iron Company. With these ore bodies belongs that deposit of the old 

 North Lee mine on Lee Hill, near Tower, the ore of which has long since 

 been exhausted. At Ely there are two and possibly three ore bodies lying 

 in an approximately east-west line, and exploited by the Minnesota Iron 

 Company by means of a number of shafts. Future developments may 

 show that these ore bodies are actually continuous and form one immense 

 body of ore. 



