Nis. a, 
SUPPLEMENTAL REPORT—HANGING ROCK DISTRICT, 929 
the roof of the tunnel. It can be traced distinctly for more than thirty feet. 
The seam is numbered IIIc in the section, but it will be remembered 
that the identification is not positive in the general review. 
The ledge of sandstone that lies next above is the most marked of all 
the deposits of this order in the Lower Coal Measures of the district. It 
is finely shown on Hecla Furnace lands, and yields there furnace hearth- 
stones that are well approved. It can be followed through Lawrence and 
Jackson counties into Vinton county, holding everywhere a thickness of 
not less than twenty-five feet, and sometimes rising to forty feet. It is 
no where shown better than in Bloomfield township, Jackson county. Its 
relation to the Gray Limestone renders it very easy of identification 
throughout the field. It may very appropriately be termed the Hecla 
Sandstone. 
We reach, now, the horizon of the Gray Limestone. It is five feet 
thick at the point where the measurement was taken, but a heavier body 
of it is found in some of the sections of the neighborhood. The place of 
the coal seam that is so generally found below it, Coal No. IVa, is indi- 
cated in the section, but there is not even a black line to stand for the 
seam in the actual section. As in the Hocking Valley, so in the Ohio 
Valley, the coal is wanting, while from the northern part of Lawrence 
county to the north line of Vinton county, the seam is on the whole the 
most stable and valuable of all the series. 
Over the limestone, one foot of ore is found, and over the ore, eight 
feet of fire-clay. The clay is of the plastic variety, and has been largely 
employed in pottery in past years. Its white color makes it everywhere 
conspicuous in the sections of the region. 
Over it, about fifty feet of sandstone is found in two great ledges, which 
are generally separated, however, by Coal No. V, the New Castle seam. 
The upper ledge lies immediately over the coal, and the lower one ap- 
proaches the coal very closely, also. Vertical sections, in which the 
country abounds, often show the sandstone continuous, the coal being 
entirely cut out. The New Castle Coal is, in the Ironton hills, three and 
one-half feet thick. Its quality can be judged in part by the fact already 
noted, that it has a sandstone roof. Such a cover is almost always asso- 
clated with a sulphurous coal. 
Above the upper ledge, the “Black Kidney” ore, assit is named in some 
of the Kentucky furnaces, is found. It lies from eight to fifteen feet be- 
low the Sheridan Coal (No. VI) and is without doubt identical with the 
Snow Fork Ore of the Hocking Valley. Like it, it frequently contains 
impressions of fern leaves and other vegetable tissues. 
ag 
