SCHUYLER COUNTY. 85 



and chalcedony. The easterly dip of the strata is considerably more than the 

 fall of the creek in that direction, and these beds dip below the bed of the 

 creek, before it strikes the north line of Brown county. The thin bedded 

 limestones which occur at the base of the section near Birmingham, contain 

 many of the characteristic fossils of this group, among which are Archimedes 

 Owe.nana, Productus punctatus, Agaricocrinus Americanus, Platycrinus Saffordi, 

 Spirifer Keokuk, and S. neglectus. The g'eodiferous shales above, contain the 

 common geodes, lined with quartz crystals and mammillary calcedony, and more 

 rarely, crystals of dolomite, calc spar, and zinc blende. The limestones locally 

 intercalated in the shale, contains the same species of fossils that are found in 

 the limestones below. 



Economical Geology. 



Coal. The most important and valuable mineral resource of this county 

 consists of the deposits of bituminous coal, which underlie the greater portion 

 of its surface, and especially that portion of the county lying west of Crooked 

 creek. Until quite recently, the coal of this county has had no outlet to 

 market, except as it was required for home consumption, but since the comple- 

 tion of the railroad to Rushville, and its probable extension, at an early day, 

 into and through a region further south, which is but poorly supplied with 

 coal, a ready market will be found for all the coal of this county. The upper 

 seam is the most valuable, and, from its greater thickness and excellent roof, 

 can be mined more economically than either of the lower seams. Its average 

 thickness is nearly five feet, and its product about five million of tons to the 

 square mile. It affords a hard, bright coal, which breaks with a conchoidal 

 fracture, and is traversed by vertical seams of carbonate of lime, which are 

 often stained with the oxyd of iron. The following analysis of a specimen of 

 this coal, from the mines near Pleasant View, by Mr. Henry Pratten, former 

 chemist and assistant in the Geological Survey of Illinois, is reported in Nor- 

 wood's "Abstract of a Report on Illinois Coals," page 24 : 



Specific gravity 1.286 



Loss iu coking 40. 60 



Total weight of coke 59.40 



100.00 



Analysis : Moisture 6.0 



Volatile matters 34.6 



Carbon in coke 52.9 



Ashes (deep red) 6.5 



100.00 



Carbon in coal 5*7.8 



Another analysis of a specimen from Rose's coal bank, near Rushville, from 



