200 J. J. STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



With these one comes to the end of tracing, for records are few toward 

 the west and south. At Ravenswood, in Jackson county, 25 miles west 

 from Spencer, the Pottsville appears to consist of two sandstone plates, 

 47 and 85 feet, separated by 33 feet of black slate ; but at Letart, in 

 Mason county, 10 miles farther west, the section is 



Feet 



1. Sandstone . 35 



2. Shale . 115 



3. Sandstone 20 



4. Shale ... 165 



5. Sandstone . 60 



in all, 395 feet, resting on the limestone. A well opposite Gallipolis, 

 Ohio, and about 12 miles southwest from Letart shows the interval from 

 the Pittsburg coal bed to the limestone to be only 1,125 feet, almost 400 

 feet less than at Spencer. The decrease is due very largel} 7 to loss in 

 the Pottsville, but in part to decrease in the Conemaugh, for there the 

 bottom of the Mahoning sandstone is at 597 and the Kittanning (Stock- 

 ton) coal bed is at 660 feet below the Pittsburg. The Kittanning rests 

 directly on 



Feet 



1. Sandstone 213 



2. Shale 33 



3. Sandstone 170 



with 45 feet of slate below to the limestone. The upper part of number 

 1 is the Roaring Creek sandstone of the Allegheny. Number 3 is the 

 Sharon sandstone.* 



Winfield, in Putnam county, is about 28 miles southeast from Gal- 

 lipolis and 40 miles southwest from Spencer. A complete section from 

 the Pittsburg coal bed to the bottom of the Pottsville is obtained here 

 by uniting the measurements reported by Doctor White and Mr Camp- 

 bell. It is as follows : 



Feet 



1. Pittsburg coal bed 



2. Interval -» r 539 



3. Mahoning sandstone f Conemau g h { 70 



4. Coal and shale, Upper Freeport. .-\ r 20 



5. Sandstone 108 



6. Place of Stockton coal bed 



7. Shale }- Allegheny i 52 



8. Sandstone 20 



9. Shale '. . J I 37 



* I. C. White : Op. cit., vol. i, pp. 257-258, 260, 262, 264, 274, 282 ; vol. ii, pp, 397, 398-402. 



