THE IRON SERIES, CONTINUED. 107 



2.02.23. Example 9&. Menominee District. The Menominee 

 River, which gives the district its name, forms the southeasterly 

 boundary between the Upper Peninsula of Michigan and Wiscon- 

 sin. The mines are situated about forty miles south of the Mar- 

 quette group, and the same distance west of Lake Michigan. The 

 larger number are in Michigan, but the productive belt extends 

 also into Wisconsin. They lie along the south side of an east and 

 west range of hills, which rise from 200 to 300 feet above the 

 surrounding swampy land. The geological section immediately 

 associated with the ore involves the following, all of which corre- 

 sponds to the Lower Marquette as outlined in the introduction. The 

 cherty limestone is local. (1) Norway limestone (named from the 

 Norway mine), a belt of siliceous limestone, 1200 feet thick; (2) 

 Quinnesec ore group, consisting of limestone, siliceous or jaspery 

 slates, black and flesh-colored, hydromica schists and slates and ore 

 beds, 1000 feet ; (3) Lake Hanbury slate group, slates and schists 

 with quartzose bands. Unconformably on these lies the hori- 

 zontal Potsdam sandstone. The ore occurs along two or three 



Iron Ores of the Lake Superior Region," Amer. Jour. Sci., iii., XXXII. 263; 

 ''Preliminary Paper on an Investigation of the Archaean of the North- 

 western States," Fifth Ann. Rep. Director U. S. Geol. Survey, p. 131 ; 

 Seventh Ann. Rep., p. 431 ; also, Administrative Reports, in subsequent 

 volumes. J. P. Kimball, " The Iron Ore of the Marquette District," Amer. 

 Jour. Sci. , ii. , XXXIX. 290. H. S. Munroe, School of Mines Quarterly, III. , 

 p. 43. E. Reyer, "Geologic der Amerikanischen Eisenerzlagerstatten 

 (insbesondere Michigan)," Oest. Zeit. f. Berg.- u. Hutt., Vol. XXXV., pp. 

 120, 131, 1887. C. Rominger, Geol. Survey of Michigan, Vol. IV., 1884. 

 C. R. Van Hise, " An Attempt to Harmonize Some Apparently Conflicting 1 

 Views of Lake Superior Stratigraphy," Amer. Jour. Sci., iii., XLL. p. 117, 

 February, 1891; Tenth Ann. Rep. Director U. S. Geol. Survey ; "The Iron 

 Ores of the Marquette District of Michigan," Amer. Jour. Sci., February, 

 1892, p. 115. M. E. Wadsworth, "Notes on the Iron and Copper Districts 

 of Lake Superior," Bull. Mus. Comp. Zool, VII. 1, 1880 ; "On the Origin 

 of the Iron Ores of the Marquette District, Lake Superior," Proc. Bost. 

 Soc. Nat. Hist., Vol. XX., p. 470 ; Engineering and Mining Journal, Oct. 

 29, 1881, p. 286 ; Ann. Rep. Mich. State Geologist, 1891-92. "The Geology 

 of the Lake Superior Region," in a pamphlet issued by the Duluth, South 

 Shore and Atlantic R. R., 1892. Dr. Wadsworth announces a new subdi- 

 vision of Formations in this and in Amer. Jour. Sci., January, 1893, p. 73. 

 H. Wedding, Zeitsch. f. Berg.-, Hutt.-, und Salinenwesen in Preus. Staat., 

 XXIV., p. 339. C. E. Wright and C. D. Lawton, Reps, of the Commis- 

 sioners of Mineral Statistics of Michigan, 1880, and annually to date. 

 G. H. Williams, " Greenstone Schist Areas cf the Menominee and Mar- 

 quette Regions of Michigan," introduction by R. D. Irving, Bull. G2,U. S. 

 Geol. Survey. 



