SUPPLEMENTAL REPORT—HOCKING VALLEY. 841 
everywhere hold to the Nelsonville seam. In this obvious view of the 
matter I am sustained by Mr. Thomas Black, who sunk the shaft, and 
has bored a large number of test holes in this field to determine the loca- 
tion and thickness of the Nelsonville seam. 
The Nelsonville Seam in the Sunday Creek Valley.—Passing over the rides 
from the head of the right-hand fork of Snow Fork we descend into the 
valley of the West Fork of Sunday Creek. Here the Nelsonville seam is 
seen on Priest’s Fork of the West Fork, but I have no measurements of its 
thickness. At the mouth of Priest’s Fork, at the little village of Hem- 
lock, in Perry county, we find the coal disturbed by intruding sand-rock, — 
which replaces a part of the coal, and, indeed, takes its place altogether 
at localities near by. This disturbance extends up Sulphur Fork as far 
as the sulphur spring, and from this point the coal becomes more regular, 
as we go northward. The best exhibition of coal above the sulphur — 
spring observed is at the bank of the late Samuel Lyons, where, in some 
rooms, the coal is from seven to eight feet thick, and of good quality. 
From this point the seam probably thickens to the east, for on another 
branch of the West Fork, not far distant in that direction, the seam is 
twelve fect thick. 
At an old opening on the farm of Mr. Benjamin Sanders, a little below 
Hemlock, a laminated sand-rock replaces all the upper part of the seam, 
leaving only two feet ten inches of the middle seam with the lower one. 
But not far east, we find in the bed of the stream the seam with no sand- 
rock over it, but clay shale with coal plants. Here the upper bench 
measures three feet four inches, and four feet or more of the middle bench 
are visible above the water. It would appear that the great seam had 
now gotten beyond its troubles, but a little below we find an ancient 
channel-way, in which the whole seam is cut almost square off, and the 
channel filled not with sand, but with unstratified mud, now hardened 
into a tough clay-rock. A similar removal of the coal by a square cut- 
off and replacement with clay is seen near the stream a little below. 
This eroded channel, which apparently extends to some depth below the 
coal, has no connection whatever with the other eroded channels filled 
with sand-rock. The former was probably formed by a narrow, confined 
current, which cut through the coal after it had become hard, and after- 
wards the channel was filled with mud. In the other case, it is quite 
possible that the currents of water which removed the coal also brought 
in the sand now changed to sand-rock. . A few miles north, in a railroad 
cut, I found a fine rounded bowlder of hard coal in the sand-rock over the 
same seam. I found, a few years since, in West Virginia, many angular 
fragments of coal imbedded in a sand-rock in a similar way. | 
