U. S. GEOLOGICAL SURVEY. 



R.3.W; 



3Wilt<ijM[jLho:o Nf*-lbr.< 



-f^m^ 



iiiiiiii jrmmr 



~/im/ 



looo feet abc 



Bl, SL Gw. 



7T 



rooo feet abo 



KEWEENAW SERIES. 



i{CW( Exposures of eruplives 

 South limit. 



Upper-Slate Member 



: XW M S Mica-slate exposures 



I )(W( BIS! Black slate exposures. 



; WW Q Quartzite exposures 



: WW Gw Graywacke exposures. 



PENOI' 



Iron-bearintf Member 



^^ XCO( Exposures of ferruginous schist 

 Limits of surface distribution 



Quartz 



SI.E)ipo 

 Q. E»pos 

 South 



^Exposures showing strike and dip. W Exposures show 



Lines of exploration by Wis Geo 



Scale of SectK 



DETAILED GEOLOGY OF THE 



