200 GEOLOGY OF ILLINOIS. 



hood as the Schoonmaker coal, and is found to be ten and a half feet thick at 

 Schoonmaker's shaft,, near the center of section 7, township 33 north, range 9 

 east. Its relation to other seams are still doubtful. (See further, Report on 

 Will county.) 



In ascending the DesPlaines river, from its junction with the Kankakee, the 

 sandstone of the above section, No. 7, is found at intervals for about two miles 

 on the south bank, but does not cross the river above the "feeder " aqueduct, 

 at Old Kankakee. 



The outline of the Coal Measures in this county, may be roughly stated as a 

 line running from near the northwest corner of the county, with some varia- 

 tions, in an east southeast course to the mine on AuSable creek, just above the 

 railroad; thence, southeasterly to the Groose Lake slough, and easterly to the 

 east end of the lake ; thence, northerly to the mouth of the Kankakee. 



Cincinnati Group. The shales and shaly limestones of this group outcrop in 

 the northeastern part of the county, showing most prominently upon the high 

 ground between Goose Lake and the Head of the Illinois. This outcrop con- 

 sists of coarsely granular, highly fossiliferous, ferruginous limestones, readily 

 disintegrated by the weather, which have been used, to some extent, for fences. 

 This outcrop continues southward for about a mile, and forms the bottom of the 

 north half of Goose Lake, the south half being underlaid with coal. At the 

 ford of the Kankakee, in the northwest quarter of section 36, township 34 

 north, range 8 east, beds of soft blue shaly limestone, which probably lie near 

 the base of this group, outcrop in the bed of the river, but show little upon 

 the bank, and contain but few and indistinct fossils. 



From the bed of the canal, a half mile west of Dresden, there were thrown 

 out considerable quantities of a heavy, but rather cellular ferruginous limestone, 

 in heavy layers, probably belonging below the beds above mentioned. The out- 

 crop at this point, did not quite reach the surface. Over most of the county, 

 north of the Illinois, the Alluvial and Drift deposits cover the country so 

 deeply as to allow of outcrops only along the streams. In ascending the Au- 

 Sable creek from the railroad, we frequently see scattered fragments of the 

 shaly limestones of this group, but meet with no outcrop until we approach the 

 middle of section 3, township 34 north, range 8 east, where small quantities of 

 stone have been quarried for wells and under-pinnings. From this point there 

 is a nearly continuous outcrop to some distance above the county line. Fossils 

 are numerous, such as Clisetetes lycoperdon, Pleurotomaria bilix, Orthis testudi- 

 naria, Leptsenasericea, Ambonychia radiata, Calymene sendria, etc. These beds 

 were struck at one hundred feet, in a boring through the boulder clay at Mi- 

 nooka. 



A small outcrop of rock of this age is exposed in the bed of Collins' s run, a 

 branch of the AuSable, in the southwest quarter of section 18, of the same 



