124 J. J. STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



the red beds reach down into the Allegheny, for beginning at 503 feet 

 below the Pittsburg is a great mass of red shale 64 feet thick and ex- 

 tending to the Kittanning horizon. In the same region Professor An- 

 drews reports the Brookville coal bed at about 688 feet below the Pitts- 

 burg, but the interval from the Pittsburg to the well curb was not meas- 

 ured carefully and the difference in interval may be apparent, not real. 

 Several miles farther south and near the Ohio the interval seems to be 

 about 713; the measurement is approximate, but the increase is to be 

 expected in this direction. At Marietta, 6 miles west from the last, the 

 interval seems to be somewhat less than 725 feet, as will be seen in the 

 discussion of the Conemaugh of this region. It is worthy of note here 

 that in Monroe and Washington the Brookville is the only persistent coal 

 horizon.* 



Meigs county is south from Washington, along the Ohio river. Here 

 also, for the most part, the Allegheny is deeply buried and the exposures 

 rarely go down to the Upper Freeport, even in the western part of the 

 county, where that coal bed is at 112 feet below the Upper Cambridge, 

 about 85 feet below the Lower Cambridge limestone. The only available 

 record is at Pomeroy, on the Ohio river, where the Cambridge limestone, 

 apparently the Lower, is at 285 feet below the Pittsburg (Pomeroy) coal 

 bed, about 40 feet more than at 6 miles west. The bottom of the Mahon- 

 ing is at 431 feet, and at 15 feet lower begins a sandstone 58 feet thick. 

 The first coal bed is at 529 feet below the Pittsburg, the second at 580, 

 and the third at 675 feet. The first is at 210 feet below the Cambridge 

 limestone. The lowest coal at 390 feet below the Cambridge is 10 feet 

 above a massive pebbly sandstone, 62 feet thick, separated by 7 feet of 

 shale from another thick sandstone, in which the well was stopped. This 

 bottom bed appears to be the Brookville, as the interval from Pittsburg 

 to Cambridge is fully 40 feet less than at the exposures east from Mari- 

 etta, where the interval to the Ames is about 230 feet. Excepting that 

 at 529 feet, the coals in the Pomeroy well are indefinite, being mere 

 streaks distributed through 11 feet of shale, so that the condition at 

 Letart, 10 miles east, in Mason county of West Virginia, is that to be 

 expected, for there the coals are wholly absent from the Allegheny, f 



Keturning to the western outcrop and entering Vinton county, south 

 from Hocking and west from Athens, one reaches the "Hanging Rock" 

 district, embracing portions of Vinton, Jackson, Scioto, Athens, Gallia, 

 and Lawrence counties, to the southern boundary of Ohio. In this nar- 



* E. B. Andrews : Vol. ii, pp. 497, 502. 



E. Orton : Vol. vi, p. 399. 



J. A. Bownocker : Bulletin no. 1, pp. 161, 169, 176. 

 -j- E. Orton : Vol. vi, p. 397. 



