30 j. j. stevenson carboniferous of appalachian basin 



The Monongahela Formation 

 correlation 



The practically continuous area of Monongahela is confined to the 

 southwest four counties of Pennsylvania, a narrow strip in eastern 

 Ohio, and central West Virginia. Small outlying patches remain east 

 from the AUeghenies, in the First and Second basins of Pennsylvania, 

 and, at the south, beyond the Kanawha river in West Virginia. The 

 area in which this formation remains is far within that of the Cone- 

 maugh, except at the east. 



The formation, as limited by Doctor I. C. White, has the Pittsburg 

 coal bed as the ' lowest and the Waj^nesburg coal bed as the highest 

 stratum. The thickness varies from somewhat more than 400 feet in 

 central West Virginia to about 140 feet at the most northerly exposure 

 in Jefferson county of Ohio. This formation is characterized by notable 

 variation in thickness of intervals and in composition of the rocks, as 

 well as by local irregularities of deposit, whereby every student in the 

 several parts of the area has been led into serious errors of correlation. 

 These have made study of the Monongahela more perplexing than that 

 of any earlier Carboniferous formation. 



In ascending order, the important members of the formation are : 



Pittsburg coal bed. 

 Pittsburg sandstone. 

 Redstone limestone. 

 Redstone coal bed. 

 Fishpot limestone. 

 Lower Sewickley coal bed. 

 Sewickley sandstone. 

 Upper Sewickley coal bed. 

 Benwood limestone. 

 Tyler red beds. 

 Ritchie red beds. 

 Unioutown limestone. 

 Uniontown coal bed. 

 Unioutown sandstone. 

 Waynesburg limestone. 

 Little Waynesburg coal bed. 

 Waynesburg coal bed. 



The Pittsburg coal bed Maryland: Cumberland, Elkgarden, Great 



H. D. Rogers, 1839. vein, Pittsburg. Pennsylvania : Pittsburg, 



Connellsville, I. Ohio : Federal creek, 

 Pomeroy, Lower Barnesville, VIII, Pitts- 

 burg. West Virginia : Pittsburg. 



