POST-WOODFORDIAN MOLLUSKS 



Fig. 2 - Excerpts from Aurora North and Sugar Grove, Illinois, 7.5-minute quadrangle maps, 

 contour interval 10 feet with dotted 5-foot contour, showing the Batavia W bog and 

 the location of the hand-auger boring, locality 136. The basin is situated in a 

 re-entrant of the St. Charles Moraine; it is partially drained by a channelized 

 brook, "Lake Run." 



southern end of the depression (fig. 2) . The bog, at least in the northern part, 

 bears a layer of peat to a thickness of 4 to 5 feet; this is being harvested 

 commercially by Batavia Soil Builders as soil conditioner. The hand-auger 

 boring penetrated nearly 5 feet of peat; the hole terminated in nonfossiliferous, 

 unctious clay, where it had to be abandoned because of sidewall collapse. 



