528 CHARLES S. PROSSER 



in the western part of the state, which allowed the Sharon conglomerate and 

 its associated coal group to be deposited.' 



Pottsville sandstone is used by Mr. Campbell as the name of the 

 formation in the Masontown-Uniontown folio in southwestern 

 Pennsylvania, and it now appears that there is sufificient evidence 

 to warrant the application of the term Pottsville to the Ohio 

 formation, as has been done by the United States Geological 

 Survey. '^ 



9. In the later reports of the Ohio Survey the following main 

 divisions of the " Conglomerate group " were given as succeeding 

 the Sharon conglomerate in the following order : Sharon coal, 

 Lower and Upper Massillon sandstones, Lower and Upper Mercer 

 groups, and Homewood sandstone, the last one named forming 

 its upper part ; 3 while in Pennsylvania, in Crawford county, along 

 the Ohio line. Dr. L C. White gave the Pottsville as composed 

 in ascending order of the following divisions : Sharon, Con- 

 oquenessing, Mercer group, and Homewood sandstone. The 

 Sharon Division consisted in ascending order of a conglomerate, 

 Lower shales. Coal and Upper iron shales, and the Conoquenes- 

 sing division of the Lower and Upper sandstones separated by 

 the Quakertown beds.'^ Finally, in the Charleston, W. Va. folio, 

 which is the next quadrangle east of the Huntington, Mr. Camp- 

 bell has used the name " Sewell formation " for the rocks of 

 Pottsville age shown in that area ; ^ but it is not known how 

 much of the " Conglomerate group " of Ohio is included in this 

 formation. It was named in 1896 by Campbell and Mendenhall 

 from the outcrops near Sewell on the New River in southern 

 West Virginia. ^ 



In northern and central Ohio it appears probable that the 

 Pottsville formation will be divided into at least two members. 

 The lower one is the conglomerate or coarse sandstone, generally 



' Geologic Atlas U. S., Masontown-Uniontown folio, No. 82, 1902, p. 7. 



2 Twenty-second Ami. Rept., Part III (1902), PI. XII. 



3 Rept. Geol. Surv. Ohio, Vol. VII (1895), p. 36. 

 '■Second Geol. Surv. Pa., Q_\ 1 881, pp. 55 ff. 



5 Geologic Atlas of the United States, Folio 72, 1901, p. 4, and sheets. 

 * U. S. Geol. Surv., Seventeenth Ann. Kept., Part II, p. 494. 



