118 GEOLOGY OF ILLINOIS. 



of coals Nos. 5 and 7 not heretofore mentioned, as tbese are the only 

 scams tbat are of sufficient thickness to justify mining operations on an. 

 extended scale at tbe present time. 



Spiller's mine, two miles north of Marion, was the first one opened in 

 this county, and has now been worked for about twenty-five years. The 

 coal is obtained by stripping along its outcrop on a small creek, and the 

 coal ranges from six to ten feet in thickness. The upper four feet is a 

 good smith's coal and presents the irridescent appearance character- 

 istic of the variety known as "peacock coal." The roof is sometimes 

 composed of hard, black shale, but locally this is replaced with a dark- 

 blue clay shale, succeeded by a dark, ash-gray limestone which iu this 

 vicinity ranges from four to six feet in thickness, and weathers to a 

 bluish-drab color on exposure. The following beds may be seen in the 

 vicinity of Spiller's mine : 



Ft. 



Shaly buff limestone 2 to 3 



Hard, dark-ash-gray limestone 4 to 5 



Blue argillaceous shale 4 to 6 



Bituminous shale „ to 2 



Coal, No. 7 6 to 10 



Fire-clay and clay shale 2 to 4 



The argillaceous shale over the coal contains numerous small, irregu- 

 lar-shaped nodules of pyritiferous clay, but no fossil plants were found 

 here, though they occur in the roof shales of this coal at Cartervillc. 

 The limestone contains but few fossils and these belong to species common 

 everywhere in the Coal Measures, such as Spirifer cameratus, Athyris 

 subtilita, and Producing longispinus. Neither the limestone nor bitumi- 

 nous shale are very regular in their development, and at some localities 

 both axe wanting, and the roof of the coal consists of clay shale over- 

 laid by sandstone. The coal has a parting of hard black shale about 

 an inch thick some two feet from the bottom of the seam, and there are 

 also several other leaf-like partings of shale separating the coal into 

 distinct layers or strata. 



A shaft sunk some years ago on tbe western borders of tbe town of 

 Marion, is said to have penetrated a coal seam six feet in thickness at 

 the depth of about fifty feet below tbe surface. This was probably coal 

 No. 5, as the outcrop of Spiller's coal is two miles north of the town, 

 and at about the same level as the surface on which the town is built, 

 and the general dip of the beds being to tbe north-eastward, that seam 

 would outcrop above the level of the town. A thin coal has also been 

 found in sinking wells in tbe town, probably No. 6, which belongs some 

 forty to fifty feet below the Spiller coal. 



The Carbondale Coal and Coke Company have opened a mine near 

 Carterville station and are working No. 7 with a sloping tunnel carried 

 down to the level of tbe coal, which lays about forty feet below the sur- 



