HURONIAN IRON ORES 



333 



The region about Lake Superior yields more iron ore than any 

 other area of equal size in the world. In 1913 the aggregate pro- 

 duction of this region was about 50,000,000 long tons, 1 which was 

 about 83 per cent of all that was produced in the United States that 



Fig. 306. M,ap showing (in black) the position of the iron-producing areas in 

 the Lake Superior region, i, Michipicoten district; 2, Kaministikwia and Malawi n 

 district; 3, Steep Rock Lake and Attikokan district; 4, Vermilion district; 5, Mesabi 

 districl; 6, Penokee-Gogebic district; 7, 8, and 9, Marquette, Crystal Falls, and Me- 

 nominee districts. 



year; of this, the Mesabi region produced nearly 34,000,000 tons. 

 The ores of the Lake Superior region are partly in the Archean 

 (about Vermilion, Minn.), partly in the older divisions of the Hur- 

 onian group (about Marquette, Mich.), but most largely in the 

 Animikean. The following table l gives the production in tons 

 for the principal areas for certain years preceding 1911: 



