482 
The Ohio Naturalist. 
[Vol. IX, No. 6, 
THE CONEMAUGH FORMATION IN SOUTHERN OHIO . 1 
D. Dale Condit. 
Introduction. 
During the summer of 1907, the writer was engaged by the 
Geological Survey of Ohio in tracing and mapping the Pittsburg 
and Pomeroy coals in southern Ohio. The seams were traced 
from the Ohio River in Lawrence County northeastward across 
Gallia, Meigs, Athens and into Morgan County. This field work 
gave the writer an extensive acquaintance with the Conemaugh 
as far down the section as the Cambridge limestone and is the 
basis of this paper. 
Nomenclature of the Formation. 
The term Conemaugh was first applied by Franklin Platt, 2 in 
1875, to his so-called “Middle Barren Measures” and “Mahoning 
sandstone.” Later the name was used in Maryland 3 to designate 
all the rocks between the base of the Pittsburg coal and the top of 
the Upper Freeport coal. With these limits, the name is today 
in general use throughout the Appalachian Basin. In 1901, 
Charles S. Prosser 4 adopted for Ohio the formation names 
Allegheny, Conemaugh, Monongahela and Dunkard of the 
Maryland Survev in place of Lower Productive, Lower Barren, 
Upper Productive and Upper Barren Coal Measures as adopted 
by Dr. Orton from Rogers’ classification in Pennsylvania. 
Generally, the Allegheny, Conemaugh, Monongahela and 
Dunkard are ranked as formations, but Dr. I. C. White, in his 
reports on the Coal Measures of West Virginia 5 6 , prefers to 
consider these as series. 
General Description. 
The thickness of the Conemaugh in southern Ohio is usually 
325 to 375 feet which is little more than half the thickness found 
along the northern outcrop in Pennsylvania. 0 A shaft at 
Canaanville, Athens County, shows the interval between the 
Pittsburg and Middle Kittanning coals to be 436 feet. 7 Although 
the base of the Conemaugh can not be conclusively located in this 
shaft section, it is probable that the formation is here less than 
375 feet thick. The following general section shows the prin- 
1. Published by permission of J. A. Bownocker, State Geologist. 
2. Sec. Geol. Surv. Pa., H. p. 8. 
3. O'Harra: Maryland Geol. Surv. Allegany County, 1900, p. 86-118, and Prosser: 
Jour., Geology, Vol. IX, 1901, p. 426. 
4. Am. Jour. Sci. 4th Ser. Vol. XI, March, 1901, p. 199. 
5. West Virginia Geol. Surv. 1908, Vol. Ila, p. 622, and Geol. Surv. Ohio, 4th Ser., 
Bull. 7, p. 11. 
6. J. J. Stevenson, Carboniferous of ttie Appalachian Basin, p. 346. 
7. Geol. Surv. Ohio, 4th Ser., Bull. 9, p. 212. Depth of shaft should read 442 ft. instead 
of 412 ft. 
