JEFFERSON COUNTY. 719 



given in charts Nos. 3 and 4, which accompany Vol. I of this report. 

 These charts include a series of sections taken along the Ohio, from 

 Smith's Perry to Mound City ; much the greater number of which are 

 in Jeflf'erson county. From them it will be seen that the general section 

 of the rocks of the county include the following strata : 



FT. 



1. The Upper Coal Group -with Pittsburgh coal (No. 8) at base 300 



2. The Lower Barren measures 450 



3. The Lower Coal Group 350 



In the northern part of the county, the upper half of the hills is 



composed of the red and olive shales of the Barren Measures, with the 

 Cronoidal Limestone — which lies about midway of that series — near the 

 top ; while the lower slopes of the valleys cover all the workable seams 

 of the Lower Coal Group, that is, Coal No. 3 (the "Creek Vein "), No. 4 

 (the " Strip Vein "), No. 5 (the " Roger Vein "), No. 6 (the " Big Vein"), 

 and No. 7 (the " Graff Vein.") Coal No. 8 generally lies above the bot- 

 tom of the valleys, and there are one hundred and fifty feet or more of 

 Coal Measure strata beneath it, which have been penetrated by numer- 

 ous borings or shafts. These include two or three thin seams of coal 

 but none of workable thickness. The section at Iiondale, on the op- 

 posite page, gives a very good view of the succession of strata in this 

 part of the county, but it does not show the famous beds of fire-clay be-- 

 neath Coal No. 3, which is so conspicuous and valuable an element in 

 the mineral resources of this part of Ohio. In the lower part of the 

 Yellow Creek Valley, and along the Ohio, this bed is well developed and 

 largely worked. 



In the central part of the county, about Steubenville, the hills are 

 capped with the Pittsburgh Coal, with its associated limestones. Below 

 these, to the level of the Ohio, succeeds the great mass of shale and sand- 

 stone which forms the Barren Measures. The first of the Lower Coal 

 Group — Coal No. 7, which in the northern part of the county lies two 

 hundred feet above the river, is carried down by the rapid southerly dip, 

 and reaches the river level near the mouth of Wills Creek. At Steuben- 

 ville it would be found some fifty feet below the river, but it apparently 

 runs out here, and the first workable seam found in the shafts is No. 6 — 

 the second from the top of the Lower Group of coals. 



In the southern part of the county, the dip has carried the Steuben- 

 ville shaft (No. 6), nearly two hundred feet below the river, and the 

 Pittsburgh Coal, (No. 8), has come down in the hills so as to underlie 

 much of the surface, and is quite extensively mined. Still farther south 

 Coal No. 6 passes beyond present reach, and Coal No. 8 is the chief source 

 of the supply of coal. At the mouth of the Wegee this, too, passes be- 

 neath the river. 



