PRE-ILLINOIAN TILL IN SOUTHERN ILLINOIS 



11 



miles west of the village of Schuline, a tributary to Little Plum Creek has 

 undercut its west bank to make the exposure. The cut lies just south of the 

 road in the north center of the NE. #, Sec. 24, T. 5 S., R. 7 W., Lat. 38°05' 

 N., and Long. 89°49' W. (Fig. 1). 



The topography of the vicinity is that of a monotonously flat till plain 

 iissected by valleys 30-80 feet deep, many of which have small valley flats. 



The drainage pattern, typically 

 dendritic, shows the valleys to be 

 mainly post-Illinoian in their 

 origin. The exposure was re- 

 visited by the writer in the com- 

 pany of Dr. M. M. Leighton, G. 

 F. Moulton, R. M. Leggette, and 

 W. Goddard, to whom thanks 

 for helpful criticism and sug- 

 gestion are given. 



TOPOGRAPHIC POSITION OF 

 EXPOSURE 



In the exposure, made by 

 the stream's undercutting its 

 west bank on the outside of a 

 meander swing, glacial drift is 

 exposed in a bluff 175 feet long 

 and 52 feet high, so steep that 

 footholds had to be cut in order 

 to examine the details of the 

 face (Fig. 2). 



From the top of the cut, which is in a bit of a spur between the main 

 and a tributary valley, the land surface slopes westward, away from the 

 nain valley. This topographic position is noteworthy, for it means that 

 slumping could not have altered the original relations of the material. 



TABLE I 

 Description of the Material (Fig. 3) 



|:l..ffijjpf 



tg&Tfl* 



^Ifcki *4M R"''- 







1 s \s'.^F? 





.d|B 



--.. * H 



i m 



■ ^ - v" ' 



111 





'"^'^HB 





-^ : ■-. ' ff^S 



■fe. . .A 



•-'s:~ ; *^S 



Fig. 2. — Schuline cut 



Section 1 Feet 



Loess 3-5 



Gumbotil, Illinoian 2 



Till, sand, and gravel leached 12 



Loess, dense, leached 15 



Till, leached 6-8 



. Till, calcareous 5% 



Section 2 



Feet 



Till, leached 13 



Till, calcareous 3 



sandstone, eg % 



Loess leached 12-14 



Gumbotil 3 



Till, leached 6 



Till, calcareous 5% 



