386 



GEOLOGY. 



of dip. This is true at some points in eastern Wisconsin, about Chicago, 

 and at points in Indiana. (Fig. 181.) 



The Salina (Cayugan) Series. 



The Salina series. — The formation or group of formations next 

 succeeding the wide-spread Niagara limestone differs from it so widely 



2d Guelph fauna; upper Shelby dolomite. 



Lockport dolomites. 



1st Guelph fauna; lower Shelby dolomite. 



Lockport dolomites, largely covered. 



Rochester shale. 



Fig. 180. — Figure showing the relations of the Guelph to the other members of the 

 Niagaran series. (New York Geol. Surv.) 



both in distribution and character as to indicate that considerable 

 geographic changes had intervened. It extends somewhat farther 



-10 



7 



24 



6 



8 



5 ' 



3, 



4 



? 



3 ^ 



60' 



2 









2 ' 





1 



Fig. 181. — The Wabash dome in the Niagara limestone. (Kindle.) 



east than the Niagara, and occurs in the Appalachians of Pennsyl- 

 vania and farther south, where the Niagara is not known to be pres- 



