STRATIGRAPHIC SUMMARY. 625 



Upper Siluric or Monroan. 



Upper Monroan or Detroit River series. 

 d. Lucas dolomite. 



c. Amherstburg dolomite. 

 h. Anderdon limestone. 

 a. Flat Rock dolomite. 



{Small hiatus and dis conformity.) 

 Middle Monroan — Sylvania sandstone. 



{Small hiatus and dis conformity.) 

 Lower Monroan or Bass Islands series. 



d. Raisin River dolomite. 

 c. Put-in-Bay dolomite. 

 h. Tymochtee beds. 



a. Greenfield dolomite. 

 Middle Siluric or Salinan. 



Salina shales, gypsum salt and dolomites. 

 Lower Siluric or Niagaran. 



Niagaran dolomite, etc. (including Guelph and Clinton). 

 Subformation. 



Upper Ordovicic — Hudson shales. 

 In Wisconsin occurs the most complete section of the Lower 

 Siluric or Niagaran, the formations (mostly limestones and 

 dolomites) exceeding 700 feet in thickness. The series is as 

 follows : 



Superformation. 



Milwaukee dolomites (Hamilton) or more rarely, Mon- 

 roan dolomites. 



{Great hiatus and dis conformity.) 

 Lower Siluric or Niagaran. 

 Guelph dolomite. 

 Racine beds. 

 Waukesha beds. 



(Comprising northward.) 

 Upper coral beds. 

 Lower coral beds. 



Byron beds. 

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