MONONGAHELA FORMATION 53 



Feet Inches Feet Inches Feet Inches 



7. Lower Sewickley coal bed....... 6 10 



8. Fishpot limestone and clay 7 6 11 28 6 



9. Shale and black shale 8 20 39 



10. Redstone coal bed 2 4 5 11 



11. Redstone limestone 14 5 13 9 



12. Slates 24 25 24 



13. Pittsburg coal bed 



Coal 2 10 10 



Slate 31 ^ 



Coal 1 I 50 27 6 



Slate 21 3 



Coal and slate 5 5 12 6 



Main coal -, 10 10 10 



Thus giving for the Pittsburg horizon the thickness of 68, 66, and 51 

 feet, decreasing southwardly. 



Both of the Sewickley beds are present near the Youghiogheny and 

 are separated by the Sewickley sandstone; but the sandstone disappears 

 southwardly, and at Uniontown as well as at Leith there is only one bed, 

 and that at the place of the Upper, while the Fishpot limestone has 

 made a notable increase. The interval from the Benwood limestone to 

 the Eedstone coal bed shows a great increase southwardly, but that from 

 the Eedstone to the Pittsburg, as here defined, shows little change, only 

 3 inches. The interval from the Eedstone coal bed to the main divi- 

 sion of the Pittsburg decreases from 96 feet at Leisenring to 78 at 

 Leith. The condition shown in the lower part of the section prevails 

 certainly to some distance north from the Youghiogheny river, for at 

 Connellsville a "rider" coal, one foot thick, is at 14 feet above the roof 

 division. The decrease is slow in the northerly direction, for at Moimt 

 Pleasant, in southern Westmoreland, the Eedstone is still a little more 

 than 80 feet above the main division of the Pittsburg; but the decrease 

 southwardly is rapid, for on the National road, at two miles southeast 

 from Leith, the Eedstone and Sewickley are 50 and 90 feet above the 

 Pittsburg, both Eedstone and Fishpot limestones being present. Six 

 or 8 miles south from Leith the normal condition of the Pittsburg is 

 found and a complete measurement along the road shows : 



Feet 



Waynesburg coal bed 316 



Uniontown coal bed ,. 241 



Lower Sewickley coal bed 80 



Redstone coal bed 30 



feet above the Pittsburg, with the Waynesburg, Uniontown, Fishpot, 

 and Eedstone limestones all present and the Sewickley sandstone over- 



