162 GEOLOGY OF OHIO. 
of the coal. From the latter fact it is known as the Flint Vein in a 
portion of the county. 
The seam is mined in Lawrence county in a small way under the 
name of the Conway coal. 
The coal of this seam, so far as known, is everywhere of the open- 
burning variety. Aside from this fact, no general description of the 
seam can be given. Its ash is sometimes white and sometimes red in 
color, and is never very low in proportion. Various degrees of strength 
in the coal are shown in the several fields in which it is most largely 
worked. 
7 AND 8. THE CLARION CoAL—LOWER AND UPPER. 
Synonyms.— Limestone coal of Jackson and Vinton counties, Coal No. 4 of Mahoning 
county, Coal No. IVa, Report on Hanging Rock District, vol. III. 
Under the above designation the Clarion and Scrub Grass coals of 
Western Pennsylvania are included. Both seams fail for the most part 
in all of the northern border of the Ohio field. In Perry county, one 
of them is found 16 inches thick, at New Lexington and vicinity. It 
makes no increase of volume until Vinton county is reached, but there 
it thickens into a workable seam, which has great steadiness and value 
throughout Vinton and Jackson counties. It disappears again in Law- 
rence county, and is scarcely found at all south of the Ohio River. In 
the district of its best development, it is the main reliance for fuel and 
for the production of steam. It is known as the “ Limestone coal,” 
from its close association with the Ferriferous limestone. This stratum 
makes the roof of the coal in many instances, but sometimes a few feet 
of shale intervene between it and the coal. The maximum interval 
observed is 18 feet. ‘There is no clear indication of a division of the 
seam into two in Southern Ohio. The character of the coal throughout 
the region referred to is quite uniform. It is a bright, well-jointed, 
rather weak coal, burning freely, with not an excessive amount of ash, 
but always high in sulphur. The ash is generally purple in color. In 
several of these respects it is clearly distinguished from Coal No. 4 of 
Newberry in the region where this latter seam is best shown, as, for 
example, in Stark county. 
