MONONGAHELA POEMATION 49 



but at a mile west from Salisbury this limestone is only 55 feet above 

 the coal bed, which is 13 and at another exposure 18 feet above the Pitts- 

 burg. The coal bed is triple, 6 feet 1 inch thick and with the thick bot- 

 tom bench seen at the last exposure of the "Redstone." Black shale 

 seems to fill the interval to the Pittsburg. No trace of coal appears at 

 35 to 40 feet above the Pittsburg, nor is any coal found at that horizon 

 anywhere south from a line passing east and west at 3% miles south- 

 west from Meyersdale. The coal bed, 11 to 18 feet above the Pittsburg, 

 is evidently the "Eedstone" and the decreased interval is due to dis- 

 appearance of the sandstone. Followed southward, this bed, termed the 

 "rider" in the Somerset county report, constantly approaches the Pitts- 

 burg, the interval becoming 6, 4, and 1 foot. Very near the southern 

 end of the area, Mr W. G. Piatt measured : 



Feet 



1. Concealed 15 



2. Ferruginous sandstone 9 



3. Concealed 11 



4. Coal bed Blossom 



5. Clay 6 



6. Limestone 10 



7. Concealed 12 



8. Coal bed 4 



9. Slate 4 



10. Pittsburg coal bed 10 



and the coal bed, Number 4, exposed near by, is very like the "Union- 

 town" of the northern section. It is taken to be the "Eedstone" in the 

 Somerset County report. The underlying limestone is almost exactly 

 the same in composition with the 160-foot limestone at the north, the 

 variation being barely one per cent in any constituent. It disappears 

 quickly southward and the Ferruginous sandstone is very near the Pitts- 

 burg at the most southern exposure. 



Stevenson's conclusion was that this limestone at the southern end is 

 the 160-foot limestone of the northern end; that the coal overlying it 

 is the "Uniontown," and that the "rider" of the southern is the "Red- 

 stone" of the northern portion. He regarded all the higher beds as 

 splits from the Pittsburg, but he was unable to correlate them with beds 

 farther west. 



The Pittsburg coal bed shows unusually abrupt variations in structure 

 and quality. At the north it is divided into many benches and the sec- 

 tion at one pit cannot be duplicated at another. Southward from Salis- 

 bury it is apparently solid coal in the 8 feet above, but the foreign mat- 



