WISCONSIN. 



139 



Wisconsin. 1 



LIST OF THE GEOLOGICAL FORMATIONS IN WISCONSIN: 



20. 



10. 



7. 

 5 c 



Quaternary, 



Hamilton, (Milwaukee Cement 

 Rock,) 



Lower Helderberg. 



Niagara Limestone, 3 

 5 b. Clinton, 4 

 4 c. Cincinnati Shale. 

 4 b. Galena Limestone. 



4 a. Trenton Limestone. 5 



3 c. St. Peter's Sandstone, (Chazy of 



New York ?) 



3 a. Lower Magnesian,(Calciferous.) p 

 2 b. Potsdam Sandstone. 7 



Copper bearing series. 

 1 b. Huronian. 

 1 a. Laurentian. 



1. Prepared by Professor T. C. Chamberlin, of Beloit, the State Geologist, and Professors R. 

 D. Irving and M. Strong, Assistant Geologists. 



2. Including the Champlain and Terrace. 



3. Including four sub-divisions in the southern part of the State and six in the northern, 

 among which are the Racine and Guelph limestones. 



4. The Clinton produces the Iron Ridge iron ore, the fossil ore of other States. 



5. Including two sub-divisions in the lead region and four in southeastern Wisconsin. 



6. The Calciferous may include more than the Lower Magnesian. 



7. Including several sub-divisions, among them the Madison sandstone and the Mendota lime- 

 stone. 



