LITEEATCTEE ON STUEGEON RIVBE TONGUE. 461 



the North belt (i. e., the Felch Mountain tongue). These may represent the north 

 side of the trough or basin, of which this iron belt is the south outcrop. No iron 

 has, however, been found, so far as I know, on this range. 



In Romiuger's first report on the Menominee district only a single 

 reference is made to this area. He declares that a series of test pits pnt 

 down in the W. ^ sec. 26, T. 42 N., R. 29 W., and in the SW. ^ sec. 14, 

 T. 42 N., R. 30 W., are in decomposed granite.^ 



A specimen of the conglomerate referred to by Brooks as overlying 

 the marble in the belt 5 miles north of Felch Mountain is described and 

 pictured by Van Hise' in his paper on the Principles of Noi-th American 

 pre-Cambrian Geology (see also PL LIU). It is stated to be from the 

 Felch Mountain district. The more exact location of the ledge from v^hich 

 it was obtained is near the northwest corner of sec. 17, T. 42 N., R. 28 W., 

 in the Sturgeon River tongue. 



Thus the only distinct reference to a tongue of sediments north of the 

 Felch Mountain range is that of Brooks, although the existence of sedi- 

 mentary rocks in this portion of the Menominee district was reported hj 

 Hubbard and Burt. Brooks believed that the Sturgeon River rocks repre- 

 sented the northern rim of a syncline whose southern rim constitutes the 

 i'elch Mountain range, although both he and Rominger discovered a 

 granite-schist complex underlying the country between the two areas of 

 fragmental rocks. 



EEIjATIOlSrS BETWEEN THE SEDIMENTARY ROCKS AND THE GRANITE- 

 SCHIST COMPLEX. 



As has already been stated, the country between the Sturgeon River 

 tongue of sediments and the Felch Mountain tongue is underlain by a com- 

 plex of granites and various schists, traversed by fresh and altered diabases 

 and by granite and quartz veins. Brooks recognized these rocks as pre- 

 senting a Laurentian aspect, although he felt constrained to call them 

 Huronian, because of the supposed structural difliculties involved in any 

 other view of their age. 



No contacts of this granite-schist complex with the bedded rocks of 

 the Sturgeon River tongue have been discovered. Nevertheless, there can 

 'be little question as to the relative ages of the two series. As has been 



1 Geol. Survey of Michigan, by C. Rominger, Vol. IV, 1881, pp. 198-199. 



2 Sixteenth Ann. Kept. U. S. Geol. Survey, 1896, p. 801 and Pi. CXV. 



