M <>\ HOE COUNTY. 281 



Economic Geology. 



Building Stone. There is no county in Southern Illinois more abun- 

 dantly supplied with building stone of various qualities than this, and. 

 it is s< generally distribute:! over all portions of the county as to be 

 easily accessible to every neighborhood. The stratified rocks of this 

 county are something more than a thousand feet in thickness, and fully 

 out- half of this may be considered of economical value for all the ordi- 

 nary uses for which a building stone is required. We will take the seve- 

 ral groups, in their descending order, and briefly notice the building 

 material they will afford. 



The Coal Measures afford little or no building stone of any value, 

 though in the vicinity of Gall's coal bank the limestone over the coal 

 might be used for rough walls in the absence of a better material from 

 the underlaying groups. 



The Chester group will furnish an unlimited amount of excellent 

 building stone, especially from the sandstone that forms the base of the 

 group. This sandstone is from 60 to 75 feet thick, and nearly the whole 

 of it. at some points, may be used as a building stone. It is generally 

 pretty evenly bedded, but sometimes shows a concretionary structure ; 

 but where this is the case, as at the quarries east of Waterloo, the rock 

 splits evenly, and can be readily quarried in blocks of the proper size. 

 It works easily under the chisel, hardens on exposure, and may usually 

 be relied on as a durable stone. This sandstone outcrops at many 

 points on Stone creek and Prairie du Long, also on Horse creek and its 

 tributaries, in the south-eastern portion of the county. It is also well 

 exposed on the X. E. qr. of Sec. 6 in T. 2 S., E. 10 W., and at some 

 other points along the synclinal coal basin between this and the river 

 bluffs west of Columbia. The limestones of this group also furnish 

 some very good material suitable for rough walls, especially along the 

 southern course of Prairie du Long creek, in T. 3 S., R. 8. W. 



The upper division of the St. Louis group forms the bed rock over a 

 greater surface area than any other formation in this county, and there- 

 fore the building stone it affords is more generally used. The rock is 

 mostly a compact, fine-grained, bluish-gray limestone, weathering to 

 a nearly white color, and generally lying in regular beds, varying from 

 a few inches to two feet in thickness. Extensive quaries are opened on 

 the outcrops of this limestone in the vicinity of Columbia and Waterloo, 

 to supply the demand for rough walls, as well as for curbstones and 

 flagging, to which the thin beds of this group are well adapted. Two 

 miles west of Waterloo the upper layers of this group consist of a light- 

 gray or nearly white oolite, in beds from six inches to two feet thick. 



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