282 D. WHITE — DEPOSITION OF APPALACHIAN POTTS VILLE 



Nuttall sandstone represents another broadly extended arenaceous sheet, 

 though it is less distinct to the southward, where the entire Pottsville 

 section is marked by the frequent recurrence of massive sandstones, 

 many of which, in the Alabama coal fields, are conglomeratic. The 

 Mercer group, of relatively insignificant thickness and deposited under 

 quiescent conditions in western Pennsylvania, is represented by more or 

 less conglomeratic beds in the anthracite districts, while in the central 

 and southern Appalachian regions its representatives, at the top of the 

 Kanawha formation of southern West Virginia and in the Wise forma- 

 tion of southwestern Virginia, are greatly expanded and but little dis- 

 tinct lithologically from the strata enveloping them. In Tennessee the 

 Anderson formation, whose lower half at least is Mercer, marks another 

 period of increased proportion of the arenaceous sediments throughout 

 the central and southern Appalachian region. The Anderson appears 

 to be laterally continuous with the Harlan sandstone of eastern Ken- 

 tucky and the Charleston sandstone of the Kanawha region of West 

 Virginia. 



