ILLINOIAN AND KANSAN MOLLUSCAN FAUNAS 



Time- 



Strot i graphic 



Units 



WESTERN ILLINOIS: 



Rock- Strati g r aph ic 

 Units 



SOUTH- CENTRAL and 

 EASTERN ILLINOIS: 



Roc k- Stratigraphic 

 Units 



SANGAMONIAN 

 STAGE 



c 

 o 



o 



E 

 o 



■o 



o 



</> 



o 



Berry Clay 

 Mem ber 



Radnor Till M. 

 Toulon M. 



Hulick Till M. 

 Duncan Mills M. 





c 

 o 



o 

 E 



o 

 u_ 



o 



V) 



o 



1 



Berry Clay 

 Member 



(unnamed till) 

 Roby Silt M. 



Vandalia Till M. 

 Mulberry Grove M. 



Smith boro Ti II M. 





2 



<I UJ 



_l 



JUBILEEAN 

 SUBSTAGE 



in 



*«— 



a> 



c 



-o 



c 

 o 



<u 



> 

 o 



-o 



c 

 o 



> 

 o 



_i 



MONiCAN 

 SUBSTAGE 







LIMAN 

 SUBSTAGE 



Keltervi lie Till M. 



Petersburg Silt 



Petersburg Silt 



YARMOUTHIAN 

 STAGE 



c 

 o 



o 



E 

 t_ 

 o 



U- 



V. 



a» 



c 

 c 

 o 

 00 



Lierle Clay Member 



c 

 o 



o 

 E 



o 

 u_ 



<u 



c 

 c 

 o 

 00 



Lierle Clay Member 



Tilton Till M. 

 Hillery Till M. 

 Har m a tt a n Ti II M. 

 Belgium M. 

 Hegeler Till M. 



KANSAN 

 STAGE 



(Unnamed tills, 

 intercalated sand an 

 gravel, and silts) 



d 







Harkness Silt M. 



Fig. 2 - Pertinent Illinoian and Kansan rock- stratigraphic units in western, 

 south- central, and eastern Illinois. 



In the stratigraphic sections included with this report, the Petersburg Silt 

 is described in the Briar Bluff South, Casey North, Long Lake, and Wildcat Creek 

 Sections. For the remaining seven faunas described from the Petersburg Silt, 

 stratigraphic sections have been published for the Alton Quarry Section (Leonard 

 and Frye, 1960), Petersburg Section (Willman, Glass, and Frye, 1963; Willman 

 and Fry e, 1970), Petersburg Dam Section No. 1 (Johnson, 1964), Rushville (2.4W) 

 Section (Willman, Glass, and Frye, 1963), and Schuline Section (Willman, Glass, 

 and Frye, 1963). 



Monican and Jubileean Substages 



Ten faunal assemblages listed here were collected from deposits of Monican 

 and Jubileean age. Of these, four are from the Roby Silt Member, two from the 



