PREVIOUS WORK ON FELCH MOUNTAIN RANGE. 381 



1893. 

 Wadsworth, M. E. Report of the State geologist for 1891-92. State Board 

 of Geol. Surv. for the years 1891 aud 1892, Lansing, 1893, pp. 61-73. Dated October 

 17, 1892. 



In this brief report Dr. Wadsworth calls attention to the granite which 

 is intrusive into the sedimentary series in the Felch Mountain area. 



In the Menominee region, especially in the Felch Mountain district, these granite 

 dikes are well exposed. Here they are seen not only to cut the gneiss, but to pene- 

 trate the Republic or iron formation. Mr. Wright, in 1885, pointed out one of these 

 dikes cutting the iron series near the Metropolitan mine, on sec. 32, T. 42, R. 28 W, 

 (p. 101). 



He includes the Felch Mountain dolerites (p. 104) in his Republic for- 

 mation, and correlates this formation with Van Hise's Lower Marquette series. 



1893. 

 RoMiNGBR, C. Geological report on the Upper Peninsula of Michigan, exhibit- 

 ing the progress of work from 1881 to 1884. Iron and copper regions: Geol. Surv. of 

 Michigan, Vol. V, Lansing, 1895, pp. 1-94, 



Chronologically, this is one of the latest reports upon the Upper Penin- 

 sula of Michigan, yet in justice to the author it should be considered as 

 having priority over any articles published since Irving's, in 1887, to which 

 reference has already been made, as in that article Irving made use of the 

 observations recorded in the manuscript of this report, giving Rominger 

 full credit for them. In Rominger's report, in the chapter on the Gi^anitic 

 Group, the granite dike cutting the iron-bearing formation in the Felch 

 Mountain range is described (p. 7). He also describes a wedge-like intru- 

 sion into the highly contorted strata in sec. 33, T. 42 N., R. 28 W., as follows: 



We have here evidently before us a series of strata plicated into a synclinal and 

 another anticlinal fold, the latter ruptured by an intruding granite mass, which rock 

 is there the general surface rock and comes on the south end of the exposure in 

 contact with the uppermost ferruginous strata of the overtilted anticlinal fold (p. 8). 



The portion of the chapter on the iron-ore group which deals with the 

 Menominee region is devoted to the Felch Mountain range and to outlying 

 prospects as far north as Michigamme Mountain. The description of the 

 Felch Mountain area is in great part a condensation of earlier scattered 

 observations. The strata are given as dipping high to the north and 

 consisting of the following succession: 



The underlying rock of the iron formation is always formed of crystalline rocks, 

 granite or diorite. The lowest strata are generally heavy light-colored quartzite 



