186 J. J. STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



Wills creek, and about 515 feet at Steubenville as well as at 10 miles 

 farther south.* 



Carroll county is west from Jefferson. The careful work of the Third 

 Ohio Survey superseded the reconnaissance made by Stevenson in 1872 

 and resolved the difficulties that so perplexed that observer. Two sec- 

 tions by Professor Orton suffice to show the variations. Midway in the 

 county the Brush Creek coal bed at 130 feet below the Ames limestone is 

 45 feet above the Upper Freeport, but at 10 miles farther south the in- 

 tervals are 195 and 71 feet, both sections showing the Mahoning and 

 Cambridge limestones, the latter at 120 feet below the Ames. In both 

 sections the Lower Mahoning is shale, the Upper Mahoning, as appar- 

 ently at all localities in Ohio, being absent. The Pittsburg reds, so con- 

 spicuous farther east, are wanting and the only red bed in the section is 

 20 feet thick, at 70 feet above the Ames and underlying a limestone whose 

 top, at 115 feet, can not be more than 40 feet below the Pittsburg coal. 

 According to Stevenson, the Ames limestone is double midway in the 

 county, where the Harlem coal bed occasionally attains workable thick- 

 ness, especially near the village of Harlem. A coal horizon, evidently 

 the Anderson, is distinct at 75 to 105 feet below the Ames limestone, the 

 interval increasing southward.! 



The whole of the Conemaugh is exposed in Harrison county, south 

 from Carroll and west from Jefferson. The Ames limestone is rarely 

 more than 150 feet below the Pittsburg coal bed. Even in the southeast 

 corner of the county the interval is but 149 feet, though at 6 miles east- 

 ward, in Jefferson, it is 225. The Harlem coal bed is shown at many 

 places and occasionally attains workable thickuess. The Anderson coal 

 is distinct at 90 to 104 feet below the Ames, as is the Brush Creek at 42 

 feet above the Upper Freeport. The Elk Lick coal was seen frequently 

 as coal or coaly shale at 8 to 12 feet above the Ames limestone. ^Neither 

 the Cambridge nor the Mahoning limestone is noted in any of the sec- 

 tions. Limestone is persistent almost directly below the Pittsburg coal, 

 but aside from that none of the beds above the Ames is persistent.. J 



Belmont county, south from Harrison and Jefferson, extends to the 

 Ohio river. On the river side the exposed section reaches downward to 



* J. S. Newberry : Ohio, vol. iii, pp. 96, 99, 107, 731-732, 736, 739, 740, 746, 750, 

 751, 753. 



J. S. Newberry and Henry Newton : Vol. ii, sections, sheets nos. 1, 2. 



J. J. Stevenson : Vol. iii, pp. 765, 768, 771, 773, 778. 



E. Orton : Vol. v, pp. 50-51, 53-54, 61. 



I. C. White: Pennsylvania (Q Q), p. 282. 

 |J. J. Stevenson: Vol. iii, pp. 180, 182-183. 



E. Orton : Vol. v, p. 255. 

 | J. J. Stevenson : Vol. iii, pp. 205-206, 208. 



