MOATQNGAHELA FORMATION 59 



miles southward a limestone 5 to 7 feet thick was seen 150 feet above 

 •the coal, and at 2 miles farther south it is 170 feet. It yields a dark 

 but very strong lime and underlies a flaggy sandstone. Stevenson took 

 it to be the Waynesburg limestone, but it is more likely to be the Union- 

 town, as the other does not extend so far north, and the overlying 

 sandstone may be the Wajmesburg in the Dunkard formation. Sand- 

 stone or sandy shale overlies the Pittsburg coal and extends upward 40 

 feet to a black shale holding some coal. No other exposure was seen 

 and the Benwood limestone if present must be very thin ; but that lime- 

 stone is not less than 60 feet thick at 10 miles farther south, where the 

 Waynesburg coal bed is 250 feet above the Pittsburg. At 8 miles west 

 from the Monongahela river, in Snowden township, the Wajmesburg coal 

 bed, resting on the yellow Uniontown limestone, is 250 feet above the 

 Pittsburg and thei.Benwood limestone, in many layers separated by shale, 

 is 70 feet thick.* 



Passing over into Union township of Washington county, one finds 

 the intervals increasing, for at 6 or 7 miles from the last locality the 

 Waynesburg coal bed is 55 to 60 feet above the Uniontown and the 

 Waynesburg limestone is not present. The Benwood limestone, 60 

 feet thick, is very largely calcareous shale and the Fishpot seems to be 

 wanting, but the Eedstone makes its appearance, one foot thick and 6 

 feet below its coal bed, which is 50 feet above the Pittsburg. Sandstone 

 fills the interval below the limestone. Three miles farther southwest 

 the Fishpot is seen, 5 feet thick, and the Lower Sewickley horizon is 

 marked by 2 feet of black shale separated by 35 feet of Sewickley sand- 

 stone from the Benwood limestone, of which 50 feet were seen. The 

 Redstone limestone has increased to 3 feet. The Wa3Tiesburg coal bed 

 is 50 to 55 feet above the Uniontown, which is almost in contact with 

 its yellow limestone, 15 feet thick. Nine miles west, in Peters township, 

 the Waynesburg is 175 feet above the Redstone, or barely 225 feet above 

 the Pittsburg. The Uniontown coal bed is persistent in this region and 

 seems to be about 3 feet thick, though not often yielding good coal. 

 The Redstone coal bed is from 3 to 4 feet thick and sometimes has a 

 limestone roof and floor. Southwardly the section shows comparatively 

 little change, except in increasing intervals and in the appearance of the 

 Waynesburg limestone. The Little Waynesburg coal bed is apparently 

 wanting and the Sewickley horizons show coal only occasionally. Com- 

 bining measurements by Doctor White one has: 



* J. J. Stevenson: (K), p. 303; (K 2), pp. 375, 385, 388, 390. 



