26 ILLINOIS STATE GEOLOGICAL SURVEY CIRCULAR 304 



Pleistocene Series Thickness 



Wisconsinan Stage (feet) 



Woodfordian Substage 

 Peoria loess 



9. Loess, with lenticular inclusions of sand; loess massive, 

 gray to yellow-tan, coarse, calcareous except in soil 

 profile at top, fossiliferous; sand medium to fine and 

 coarse, cross-bedded, light tan to gray, locally mottled 

 with soft limonite, sand lentils occur throughout and 

 locally truncate bed below. Fossil snails were collected 

 both here and from the upper and presumed equivalent unit 

 in the nearby roadcut (locality 43). (P-282, P-283 loess; 

 P-286 cross-bedded sand.) Maximum thickness. 25.0 



8. Silt and fine to medium sand, thin-bedded, horizontal, gray- 

 tan, gray and yellow-tan, contains sparse Succinea cf. 

 irosvenori; occurs only as lenticular body on east side of 

 quarry, basal contact truncates pink loess below and top 

 is truncated by the cross-bedded sands of unit 8 (P-285). 6.0 

 Altonian Substage 

 Roxana silt 



7. Loess, medium to coarse, massive, pink to pinkish tan, 



weakly calcareous to noncalcareous, lenticular bodies of 



sand (P-280) occur at west side of quarry, gradational at 



top with overlying loess where lenticular bodies of sand 



and interbedded sand and silt are not present (P-281 from 



pink loess above sand body). [Re-examination of the quarry 



in September 1959 and May 1960, after the overburden face 



was significantly farther back from the buff-line and past 



the limit of the sand lentils, showed bed 9 resting on 



pink loess, above gray-tan loess that rested directly and 



conformably on bed 7. The top of the Roxana is at the 



top of the upper pink loess.] (Fauna locality 45). 17.0 



6. Silt, gray, massive, noncalcareous, gradational at top but 

 resting with sharp contact on top of soil below. (The 

 face as exposed in May 1960 showed this unit thicker and 

 with 2 feet of sand locally at base.) 4.0 



Pre-Wisconsinan Stages 



5. Silt, sandy, massive, gray, noncalcareous except locally at 

 base where it is weakly calcareous, in east side of quarry 

 has soil at top with well developed red-brown B-horizon 

 and some structure and manganese staining; westward across 

 quarry face, soil is truncated, and at west end the over- 

 lying loess rests directly on the leached till below. 

 Locally contains a sparse snail fauna. (P-278 gray loess; 

 P-279 B-horizon of soil.) 6.0 



4. Till, massive, compact, blue-gray, calcareous in lower part; 

 at west side of quarry a truncated soil was observed in 

 1958 in upper part of till; in middle part of quarry till 

 pinched out over bedrock high (P-277). 8.0 



3. Silt, massive, tan, noncalcareous, occurs in local lenses 



between till and underlying sand (P-276). 2.0 



2. Sand, with a few pebbles, massive to bedded, gray to tan, 

 noncalcareous, loose; lenticular, ranges from a few 

 inches to 6 feet in thickness (P-275). 6.0 



