4 THE PENOKEE IRON BEARING SERIES. 



slate, or mica-schist, whicli is chiefly composed of quartz and feldspar. Like 

 the Quartz-slate member, in thin section it usually reveals its fragmeutal 

 character. The area of rocks situated at the same geologic horizons as 

 these four belts, between Gogebic lake and the middle of T. 47 N., R. 44 W., 

 Michigan, does not make up so plahi a succession, so that this part of the 

 district is separated from the four belts just spoken of as the Eastei-n area, 

 and under this title is given separate treatment. 



