ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 486 



P-7626 



P-7643 



Percent 10 



Fig. 2 - Bunkum South Section, measured in cuts of Interstate Highway 64 in 

 SE^NWiNEi sec. 24, T. 2 N., R. 9 W. , St. Clair County, showing 

 percent of illite, expandable clay minerals, and kaolinite plus chlorite 

 in the clay mineral assemblage in the Peoria Loess. The complex 

 A-horizon of the Jules Soil is shown in relation to clay mineral percent- 

 ages. Sample numbers at left are ISGS file numbers. 



PALEONTOLOGY 



Molluscan faunas occur in beds 5 and 4 above the Jules Soil and in 1-2 

 below the Jules Soil in Peoria Loess at the Cottonwood School South Section; in 

 two faunal zones above the Jules Soil at the Bunkum South Section in St. Clair 

 County near the village of Bunkum; and above the position of the Jules Soil in 

 Peoria Loess in the Bald Bluff Section in Henderson County, where radiocarbon 

 dating demonstrates the age of the fauna to be equivalent to that of faunas above 

 the Jules Soil at the Cottonwood School South locality (fig. 3). While shells 

 are sufficiently abundant in the deposits in the Bunkum South Section to permit 

 dating them by the radiocarbon method, this has not yet been done. The two 

 uppermost molluscan faunas at the Cottonwood School South Section have been 



