524 CHARLES S. PROSSER 



The "Conemaugh formation" includes all the rocks between 

 the base of the Pittsburg coal and the top of the Upper Freeport 

 coal. On the Huntington folio of the Geologic Atlas of the United 

 States, Mr. Campbell has referred between 200 and 300 feet of 

 conglomeratic rocks succeeding the Kanawha black flint to the 

 " Charlestone sandstone,"^ which was named by Campbell and 

 Mendenhall in 1896 from exposures near Charleston, W. Va."" 

 and probably represents about the lower third of the Conemaugh 

 formation. The succeeding 800 feet of shales and sandstones of 

 the Huntington quadrangle are correlated with the " Braxton 

 formation" by Mr. Campbell and represented as covering all 

 that portion of southern Lawrence county, O., to the east of 

 Ironton, which is represented on this quadrangle. This forma- 

 tion, as described in this folio, probably includes about the 

 upper two-thirds of the Conemaugh and the lower part of the 

 Monongahela formation. It was named in 1896 by Taff and 

 Brooks from exposures in Braxton county in central West 

 Virginia. 3 



7. Drs. Orton and I. C. White practically agreed in tracing 

 the Lower Coal-measures or Allegheny formation from the 

 Ohio-Pennsylvania state line across the state to the Ohio River. + 

 On the Huntington folio, West Virginia-Ohio, of the Geologic 

 Atlas of the United States, Mr. Campbell used the name " Kana- 

 wha formation" for the rocks considered of this general age 

 which occur on the southern part of the sheet. - The formation 

 was described by Campbell and Mendenhall in 1896;^ but it is 

 probably somewhat greater than the Allegheny formation, since 

 it includes the rocks from the top of the Pottsville to the hor- 

 izon of the Kanawha black flint, which is given by Campbell 

 as 30 or 40 feet above the horizon which Dr. L C. White con- 

 sidered as the top of the Allegheny formation. ^ 



' No. 69, p. 4, and sheets. 



^ U. S. Geol. Surv., Seventeenth Ann. Rept., Part II, p. 508. 



^Geologic Atlas of the United States, Buckhannon folio, No. 34, p. 2, and sheets. 



^ Orton, Rept. Geol. Surv. Ohio, Vol. V, pp. 1-128, and Vol. VII, pp. 276-82 ; I. 

 C. White, Bull. U. S. Geol. Surv., No. 65, pp. 130-36. 



5 Folio 69, 1900, p. 4 and sheets. 



*U. S. Geol. Surv., Seventeenth Ann. Rept., Part II, p. 499. t Ibid., p. 4. 



