GEOLOGICAL SURVEY of IOWA . 



^5 



! p 



Azoic 



Sub.Carb 

 oriiferous 



JETamilton 



Niagar 



Trenton 



Primordial 



S'iLoitis l.iitir.slonc 

 Hiebkak /. "/«'■■> tone 



Butiinffton 



/.latest one 



Mndethoak heck i 



l/a/iiifton 



Lime&tone and 



S/ tales. 



TVtagara 

 J^imestone . 



Cin cmnati MaguofataSkaler. 



Galena 



Limestone. 



Tren lot tJJ merit/tie 



fffetets Sandstone 



JO ewer 



Ma//nesiati 

 Limestone. 



Pats-dam 

 Sa/idstane 





E 





If 1 1 10 I ! iatl ? ! .S>Wr Quartxite. 



■■A- 



■ r 



J/?/? 



uT<9 



