7o8 



C. K. LEITH AND R. C. ALLEN 



Ironwood series of the Gogebic Range and its correlatives in the 

 Marenisco and Turtle ranges. 



The similarity of the successions in the Gogebic and Marquette 

 districts is striking, and coupled with proximity would ordinarily 

 determine a direct correlation of the similar series occupying 

 identical positions in the group even were there no further evidence 

 of identity. 



CORRELATION TABLE III 



Correlation of the Huronian Group in the Gogebic 

 AND Marquette Districts 





Maxquette District 





Gogebic District 





Greenstone intrusives 



and 







extrusives 









Clarksburg volcanics 



partly 







replacing Michigamme slate 



Graywacke and slate 



Upper 



Michigamme slate carrying 



Ferruginous and cherty slates 



Huronian 



iron-bearing lenses 

 schist) 

 Goodrich conglomerate- 



(Bijiki 



and jasper 





quartzite 





Conglomerate 





Unconformity 





Unconformity 





(Deep erosion) 





Presque Isle granite 

 Tyler slate 





Negaunee (iron-bearing' 



1 for- 



Ironwood (iron-bearing) for- 



Middle 



mation and extrusive 



green- 



mation and extrusive green- 



Huronian 



stone 





stone 



(Animikie) 











Siamo slate 





Palms quartzite and quartz 





Ajibik quartzite 





slate 





Unconformity 





XT ^ *^, 





u nconiormity 





Wewe slate 





(Deep erosion) 



Lower 

 Huronian 



Kona dolomite 





Bad River dolomite 



Mesnard quartzite 





Sunday quartzite 





Unconformity 





Unconformity 



Archean 



The absence of slate above the Bad River dolomite should be 

 considered with the evidence of deep erosion in Middle-Lower 

 Huronian time in the Gogebic district which not only removed the 

 slate if it was ever present there but also the entire Lower Huronian 

 over the greater part of the range. In respect to the Middle 



