34 CHICAGO ACADEMY OF SCIENCES. 



feet and in one place, near Palatine, at lOO feet.. But it sliould 

 be borne in mind that the surface elevation in the vicinity of Pala- 

 tine is at least loo feet below the crest of the ridge in Barrington 

 Township. Mr. Sneible has found buried soil but once. This 

 was near Arlington Heights, beneath blue bowlder clay, at a 

 depth of seventy feet. The soil was underlain by a pebbly clay. 

 It contained bits of wood and was of an offensive odor. 



Mr. R. Ryan, of Bloomingdale, in an extensive experience 

 as a well borer, has found a buried soil but a few times. He recol- 

 lects its depth in but one instance, in a well in the northwestern 

 part of Schaumberg Township. It occurs at 135 to 139 feet below 

 the surface. It is of a brownish black color and has an offensive 

 odor. It is overlain by blue bowlder clay and underlain by 

 quicksand. Mr. Ryan and also other well borers have found 

 wood and peaty deposits imbedded at slight depth beneath ponds. 

 They are covered by swamp muck and pebbleless clays and 

 have probably been buried in postglacial times. Mr. Ryan re- 

 ports the soft blue till to have a depth of 100 to 140 feet in the 

 vicinity of Bloomingdale, Schaumberg and Wheaton. 



Mr. Diebold, a well borer at Downers Grove, reports a depth 

 of 100 to 115 feet of blue bowlder clay in the vicinity of Downers 

 Grove, Clarendon Hills and Hinsdale. Mr. Diebold furnished 

 the following section of a well at a l^rick yard on the crest of the 

 moraine three miles east of Downers Grove: 



1. Yellow clay (pebbly) 7 to 8 feet 



2. Grayish-blue, pebbly clay ' 112 " 



3. Fine, blue sand 39 " 



4. Limestone 40 " 



Depth of drift. 159 feet 



Mr. Diebold has frequently found a blue sand beneath the 

 blue bowlder clay in that vicinity, and if this is not present there 

 is usually white sand or gravel beneath the blue clay and overly- 

 ing the rock. 



Borings near East Du Page River strike rock at 100 feet or 

 less, and the sand and 'gravel which underlie the blue clav are 

 but a few feet in depth. 



The structure of the drift along the bluffs of the Des Plaines 

 is well exposed at several points between Lemont and Jolict. 

 There appears to be much more sand and gravel than is shown bv 

 well sections on the uplands.- There is, however, considerable 



