-2- 



Cin. 



GROUP 

 OR STAGE 



Lsconsinan" 



111 . - Kans. 



McLeansboro 



Kewanee 



Maquoketa 



Galena- 

 Platteville 



FORMATION 



Bond 



Modesto 



Carbondale 



Spoon 



Racine 



Waukesha 

 Joliet 



Kankakee 

 Edge wood 



ROCK 

 UNIT 



/ / 



0- 



700 



180 



380 



GENERAL DESCRIPTION 



Till, outwash, dune sand, loess, peat 



Till, outwash 



Alternating sequences of sand- 

 stone, shale, limestone, thin 

 coal , and underclay 



Dolomite , cherty in part 



Dolomite and sandstone 



Shale, some dolomite 



Dolomite, slightly cherty; 

 some limestone 



Ancell 



Glenwood- 

 St. Peter 



125- 

 160' 



Sandstone, some shale, chert 

 rubble at base 



Shakopee 



rz 



-jjr: 



Prairie 

 du Chien 



=z^; 



170- 

 230' 



Dolomite, some thin sandstone 



New Richmond 



so- 

 iss' 



Sandstone 



u 



Oneota 



ZI E r 



^ 



215 



Dolomite , cherty 



Gutter 



0-15' 



Sandstone 



2000- 

 2500' 



PRECAMBRIAN 



Dolomite, sandstone, some shale 



Granite 



Fig. 1 - Generalized geologic column in the La Salle area. "U" indicates 

 a major unconformity. See figure 3 for a detailed Pennsylvanian 

 column . 



