84 J. J. STEVENSON CARBONIFEROUS OF APPALACHIAN BASIN 



Feet 



9. Sandstone 75 



10. Quakertown coal bed 



1 1 . Shale and sandstone 45 to 50 



1 2. Sharon coal bed 



13. Shales 50 



14. Conglomerate 28 



The notable feature in the lower portion of the section is the great 

 increase of rock below the Sharon coal bed — an increase which in one 

 form or another becomes more and more noteworthy farther south 

 along the western outcrop in Ohio and throughout the w r hole field in 

 the states beyond. The Sharon conglomerate shows most of the features 

 observed farther north by other students, but Stevenson makes no refer- 

 ence to fragments of chert. The Sharon coal bed occasionally reaches 

 2 feet 6 inches, but is broken by clay partings into benches of dissimilar 

 coals ; but the occurrence of this bed is very uncertain ; it is wanting at 

 many places. The Connoquenessing sandstones are persistent, and the 

 Quakertown coal bed is present in the northwest part of the count}', 

 though very thin. The interval of 120 feet between the Sharon coal bed 

 and the Lower Mercer is the extreme. The Mercer coal beds are present 

 in every section where the horizon is exposed but, except in the south- 

 west corner of the county, they are insignificant. No trace of the 

 Tionesta coal bed was observed and the Homewood is never more than 

 a shal} T sandstone. The close resemblance of this section to that of 

 Lawrence county, Pennsylvania, is important, for all members of the 

 formation are here with much the same features as in the typical 

 section. This Muskingum section was made in 1872.* 



Before following the western outcrop farther toward the south, it may 

 be well to refer briefly to counties lying eastward toward the Ohio river, 

 where for the most part the Pottsville is under cover. 



Columbiana county is south from Mahoning along the Pennsylvania 

 border. Doctor White's sections in the northeastern part of the county 

 show the Upper Mercer limestone represented by chert at many locali- 

 ties along the western outcrop. A thin coal bed, at one place, rests on 

 the Upper Connoquenessing. 



Professor Newberry reports two coal beds in a boring midway along 

 the northern border which are at the proper places for the Mercer coals. 

 Borings somewhat farther south reach the Lower Mercer and show both 

 coals at 31 and 63 feet below the Putnam Hill limestone, but the Mercer 

 limestones are wanting, as they are also at the more northern locality. f 



* J. J. Stevenson : Vol. iii, pp. 230, 243. 



fl. C White : (Q 2), pp. 268-272. J. S. Newberry : Vol. iii, p. 110. E. Orton : Vol. v, p. 37. 



