ADAMS COUNTY. 57 



its lithological characters, being largely composed, like that, of the calcareous 

 portions of the marine animals that swarmed, in countless numbers, in the old 

 Carboniferous ocean in which these limestones were formed. Nearly all of the 

 purely calcareous strata of this formation, are made up of the remains of marine 

 animals, in which the Crinoidea,, or Encrinites, largely predominate, and hence 

 it has been called the Orinoidal, or Encrinital limestone, by some of the early 

 observers. It contains a good deal of chert or flint, disseminated through it 

 in seams and nodules, sometimes forming irregular layers between the limestone 

 strata, but more frequently in detached nodular or ovoid masses, in the lime- 

 stones. These chert bands and nodules furnished the flints, so much used by 

 the Indians in the manufacture of spears, arrow-heads, and other rude imple- 

 ments, and it was probably the most useful and valuable mineral known to 

 them, anterior to their acquaintance with the white man. 



This limestone will be found at the base of the bluffs, for a few miles north 

 of Quincy, but at so low a level as to be seldom exposed by the natural outcrop 

 of the strata. On Mill creek, it may be found for several miles up the creek, 

 and on all the smaller streams, to the south line of the county, it forms the 

 principal rock exposed. 



Kinderhook Group. Immediately beneath the Burlington limestone, we 

 find a series of sedimentary strata, consisting of sandy and argillaceous shales, 

 and thin beds of impure limestone, only a portion of which appear above the 

 surface in this county, to which the name Kinderhook group has been applied, 

 from their fine exposure near the village of Kinderhook, in Pike county. The 

 first considerable exposure met with in this county, was at Fall creek, twelve 

 miles below Quincy, where there is about thirty feet of this group to be seen 

 in the creek bluffs beneath the Burlington limestone. The section here is as 

 follows : 



FEET. 



Burlington limestone _ 20 



Sandy shale and sandstone 20 



Thin bedded, silicious limestone JQ 



Shale to the creek level g 



This formation is altogether about a hundred feet in thickness, and fre- 

 quently has a bed of black, or chocolate colored shale intercalated in the lower 

 portion, which has led many to the belief that coal might be found in it. 

 This black shale was reached, in the boring made just below the city of Quincy, 

 in search of coal, at a depth of about one hundred and fifty feet, but does not 

 come to the surface anywhere in this county. As it lies nearly four hundred 

 feet below any coal seam known in this country, all the time and money spent 

 in the search for coal in this formation, can only result in pecuniary loss and 

 disappointment. This group is exceedingly variable in its lithological charac- 

 ters, and at some localities, it becomes quite calcareous, and consists mainly of 

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