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 Ntlsonville seam. It is like two parentheses, or two 

 bows, placed horizontally back to back, as here shown, X. 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 thfi Nelsonville seam some force threw it up in the form of 

 an arch, it would be impossible to produce a synclinal over the arch. 

 Co il 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- 

 sidMice must nece.-sarily 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 abdve show that afterwards the work of deposition went on regu- 

 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 S'-ries w;is 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 

 Nelfonville eeam the borings show the existence of the Nelsonville seam 

 Oelow the arch. Mr. Thomas Black, whose knowledge of the coal seams 

 in the Sunday Cnek valley 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 fi, ding 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 Noriis 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 

 thck. The depths of the Nelsonville seam beneath the surface, of course, 

 varied with ihe 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 ihe dip would take it, that is, below the surface 

 in all the valleys, indeed, just where it ought geologically to be. The 



