466 STEVENSON— THE FORMATION OF COAL BEDS. [Nov. i, 



from the underlying Waynesburg coal bed, is the first important 

 member of the Washington formation. 



This sandstone was not seen in the Broad Top basin of Penn- 

 sylvania but it is present and 45 feet thick in the Potomac region of 

 western Maryland. The horizon is not reached in other outlying 

 patches of the higher coals and only occasional fragments remain 

 on the extreme east side of the continuous Washington area. These, 

 separated by intervals of several miles, consist of coarse sandstone 

 containing pebbles of small size, scattered irregularly throughout 

 the mass. At six or eight miles farther west, the rock is continuous. 

 At the northern outcrop it is from 25 to 50 feet thick, consisting of 

 sandy shale to laminated sometimes massive sandstone ; thence to 

 the West Mrginia line the same character persists, though the lower 

 part tends to become massive and the thickness increases at times 

 to 75 feet, but not at expense of underlying deposits. Oil well 

 records show that in the extreme southwest corner of Pennsylvania 

 this " Bluff Sand " of the drillers persists with thickness of 55 to 

 65 feet. Westwardly into the West Virginia panhandle the deposit 

 is somewhat thinner, less well consolidated, while the lower portion 

 occasionally contains pebbly layers. Southwardly in West Virginia, 

 I. C. White has followed the Waynesburg sandstone along the east- 

 ern and southern outcrop into Ohio. It is 50 to 75 feet thick and 

 for long distances forms rugged cliffs. At the southeast, on the 

 Pocatalico River, he found it massive, very coarse and pebbly. In 

 the interior of West Mrginia, this sandstone is persistent in all well 

 records southward to some distance beyond the Baltimore and Ohio 

 main line and westward to the middle line of Doddridge and Wetzel 

 counties. Farther west, it is seldom enough consolidated to be 

 called " sandstone " in the drillers' record. Farther south, the 

 records can hardly be compared ; typical horizons are lacking in a 

 considerable area and the region is marked by notable irregularity 

 in intervals. 



Following the northern border, one finds this sandstone 50 feet 

 thick in Jefferson, Harrison and Belmont counties of Ohio and it is 

 persistent thence along the western outcrop. In Morgan county it 

 contains layers of pebble rock ; in western Washington it is 50 feet 

 of sandstone with no pebbles reported, while in the southeastern 



