250 GEOLOGY OF ILLINOIS. 



the bed presdits a perpendicular face of solid sandstone fully twenty 

 feet in thickness. It is rather soft when freshly quarried and can be 

 easily dressed, and splits freely into blocks suitable for building and for 

 foundations walls. These quarries are located just above the level of 

 the railroad grade, and are very conveniently situated for the trans- 

 portation of the stone by railroad to the city of Peoria, or wherever 

 else it might be in demand. 



At Lonsdale's quarries, on section 14, T. 8 N., E. 7 E., the lower part 

 of the limestone- affords a durable building stone, though the layers are 

 not usually more than from four to six inches thick. This rock is in 

 common use in this part of the county for foundation walls, and there 

 are several small buildings in this neighborhood constructed with this 

 material. That portion of the bed which affords a building stone is 

 from four to six feet in thickness. 



At Chase's quarries, three miles north-east of Princeville, the lime- 

 stone is nearly twenty feet in thickness, and though for the most part 

 thin-bedded, yet the greater portion of it can be used for foundation 

 walls, flagging, etc., and is the only building stone available in that por- 

 tion of the county. The thickest layers are at the bottom of the bed 

 here, as well as at Lonsdale's, but the middle and upper portion is more 

 evenly bedded at this point, and may be quarried in thin even slabs of 

 large size. 



The limestone over coal No. 6 may answer for rough foundation walls 

 where it can be protected from the atmosphere, but is generally too 

 argillaceous to make a good building stone. 



Iron Ore. Concretionary bands of iron ore occur in the shales over- 

 laying coals No. 4 and 7, but not in sufficient quantity to be of any 

 economical importance. In the south part of the county, large concre- 

 tions of iron and clay, the former mostly in the form of the bi-sulphuret, 

 are quite abundant in the roof shales of No. 4 coal. Some of these con- 

 cretions are two feet or more in diameter. 



Clays. We found no beds of fire or potters' clays in connection with 

 the coal seams in this county, that appeared to be sufficiently free from 

 foreign matters to be of much value, but excellent brick clays arc abun- 

 dant, the subsoil clays over a large portion of the uplands throughout 

 the county being used for this purpose, and furnishing an abundant 

 supply of brick of good quality at a moderate cost. The best beds of 

 fire and potters' clays known at the present time in this State, are asso- 

 ciated with coal No. 1, of our general section of the Illinois Valley coals, 

 given on page 5, of Volume III of these reports ; and should a shaft be 

 sunk to that horizon in this county, good clays may probably be found 

 here, and mined successfully in connection with these lower coals. 



