THE CHESTER SERIES IN ILLINOIS 405 



undoubtedly present in the Mississippi River bluffs south of the 

 Big Muddy, and probably can be traced to northwestern Union 

 County, where it will connect with the belt across the southern 

 counties. 



In the southern counties the Degonia is continuously exposed 

 from Union to Hardin counties. In Union County the thickness 

 of the formation is in excess of seventy-five feet; at Simpson, in 

 eastern Johnson County, it is at least one hundred feet thick; but 

 farther east, across Pope and Hardin counties, it probably is some- 

 what reduced from the maximum thickness. There are places in 

 Union County where the formation is fully as massive as in any 

 of the sections in Jackson County, but to the east it becomes 

 somewhat more thinly bedded, although massive layers are present 

 in the formation throughout its entire extent in the state. In 

 general, in its more eastern extension, the Degonia sandstone is 

 rather paler in color and of finer texture than farther west, and in 

 .many places it resembles the Palestine somewhat closely. 



The fossils of the Degonia sandstone are like those of the other 

 Chester sandstones. The only forms that have been recognized 

 are plant remains, and of these the Lepidodendron trunks are most 

 commonly met with. 



Kinkaid limestone. — The highest formation in the Chester 

 series of Illinois is the Kinkaid limestone, named from the excellent 

 exposures on Kinkaid Creek, in Jackson County. The formation 

 is well developed in southeastern Randolph and in Jackson counties, 

 and continues across the southern counties from Union to Hardin. 



In its lithologic characters the Kinkaid more closely resembles 

 the Menard than any other Chester limestone. It has been de- 

 posited in the same sort of regular beds about a foot, more or less, 

 in thickness, the individual beds being separated by thin shaly 

 seams, and the surfaces being distinctly hummocky. Many small 

 exposures of the Kinkaid would be indistinguishable from similar 

 exposures of Menard if the stratigraphic relations could not be 

 determined. Some of the beds of the Kinkaid possess the same 

 sort of compact, hard, close- textured limestone that is so commonly 

 present in the Menard, but on the whole the Kinkaid probably 

 includes a larger amount of somewhat more crystalline limestone 



