846 GEOLOGY OF OHIO. 
surface, that point being the crown of a great arch. At the same place, 
the Bayley’s Run seam is brought down in the form of a synclinal, so as 
almost to meet the Nelsonville seam. It is like two parentheses, or two 
bows, placed horizontally back to back, as here shown, ~. Directly over 
these curves, the strata of the Coal Measures are horizontal. I must ex- 
press my dissent from this profile. If we should admit that after the 
deposition of the Nelsonville seam some force threw it up in the form of 
an arch, it would be impossible to produce a synclinal over the arch. 
Coal could not be formed at the bottom of a deep depression and at the 
same time be continuous with the coal beyond the limits of the depres- 
sion; and if a subsidence took place here after the regular Bayley’s Run 
seam was formed, so as to lower the seam fifty feet, more or less, such sub- 
sidence must necessarily flatten the arch of the Nelsonville seam under- 
neath. It must be remembered that these supposed curves were formed 
during the progress of the formation of the coal series, for the horizontal 
strata above show that afterwards the work of deposition went on reeu- 
larly without disturbance. Anticlinals and synclinals are not uncom- 
mon in our coal fields; but all I have ever seen took place after the 
whole series was formed, and all the strata undulate together. 
But the most simple and practical refutation of this geological profile, 
is the fact that everywhere in the region of this supposed arch of the 
Nelsonville seam the borings show the existence of the Nelsonville seam 
below the arch. Mr. Thomas Black, whose knowledge of the coal seams 
in the Sunday Creek valiey is more full and minute than that of any 
other person, has made a large number of borings in this vicinity for the 
sole purpose of finding the Nelsonville seam. The borings were made 
with care, and I have the utmost confidence in the trustworthiness of his 
records. From him I have received the detailed records of eight test 
wells, extending east and west across this supposed arch. Some of these 
are in the very axis of the anticlinal, some a little south and others north 
of it. In-one well he found no coal of any seam. In six, and perhaps 
in the seventh, he found the Nelsonville seam, in thickness varying from 
one foot six inches to six feet six inches. In four cases he found the 
middle or Norris seam above the Nelsonville seam, and in one case he 
bored below the latter seam where it was four feet thick, and found the 
Lower Lexington seam twenty-eight feet lower, three feet six inches 
thick. The depths of the Nelsonville seam beneath the surface, of course, 
varied with the different elevations of the surface, and with the dip of 
the seam, but they ranged from thirty-five to eighty feet. Mr. Black 
found the seam where the dip would take it, that is, below the surface 
in all the valleys, indeed, just where it ought geologically to be. The 
