MONONGAHBLA FORMATION i I 



The Uniontown is wholly unimportant. The limestones are variable to 

 the last degree.* 



Washington county, south from Noble and Monroe, is east from Mor- 

 gan and Athens. On the western border the Uniontown (Hobson) coal 

 bed is at 104, 89, and 105 feet above the Upper Sewickley (Meigs 

 Creek, Cumberland) coal bed and in three townships there is a very 

 thin coal bed at 140, 150, 135, and 147 feet above the Upper Sewick- 

 ley, which is at the place of the Waynesburg and underlies a coarse 

 sandstone, evidently the 240-foot conglomerate of Andrews. The Union- 

 town is usually a double bed, frequently underlying plant-bearing shales, 

 apparently equivalent to the bed's upper parting in Monroe. As in 

 other counties, it rests on clay and limestone, and generally one finds 

 a sandstone at a few feet above it, though at times this is replaced by 

 shale. In the northwestern part of the county a "limestone group," at 

 most 30 feet thick, inclusive of shale, is at 11 to 18 feet above the Upper 

 Sewickley; but this disappears eastwardly, so that in JSToble, as in most 

 of Washington, it is replaced by sandstone. It seems to disappear in 

 southwestward direction also, and no trace of it remains in Decatur 

 township at the southwest corner. 



The section can be followed readily across the greater part of Wash- 

 ington county almost to the Ohio river, as the Cowrun anticline brings 

 up the lower part of the formation. Along the northern border, in Salem, 

 Liberty, and Ludlow townships, the Uniontown (Hobson) coal bed is 

 about 95 feet above the Upper Sewickley, which is 85 to 100 feet above 

 the Pittsburg. The Uniontown is very thin, apparently seldom more 

 than one foot thick. Mr Minshall's section in Liberty shows it resting 

 on its clay and limestone, with a coarse sandstone at 6 feet above. No 

 trace of the sandstone at "240 feet" remains here, and the sandstone 

 overlying the Uniontown is coarser than at any other locality away 

 from the Ohio river in this county, though in other counties it is noted 

 as very coarse. In this section the Waynesburg A is 100 and the Wash- 

 ington 160 feet above the Uniontown, just as in Pleasants county of 

 West Virginia, 8 or 9 miles east of south. The interval below the Union- 

 town is filled mostly by shales and sandstone and the sandstone at one 

 to 6 feet above the Upper Sewickley sometimes becomes 50 feet thick. 

 Occasionally, however, the upper part of that sandstone is replaced by 

 red shale, 52 and 27 feet being recorded at 27 and 18 feet above the coal 

 bed. At one locality 10 feet of shale and limestone overlie the upper 



* B. B. Andrews : Vol. i, pp. 270, 273, 274, 282, 286, 287. 

 C. N. Brown : Vol. v, pp. 1061, 1062, 1063. 

 E. M. Lovejoy : Vol. vi, pp. 629, 646. 

 VII — Bull. Geol. Soc. Am., Vol. 18, 1906 



