112 GEOLOGY OF OHIO. — 
each 17 inches thick. The seam’shows the same structure at all of the 
intermediate points, so far as could be learned. At both of these en- 
tries, and all along the line, there is a heavy and characteristic de- 
velopment of the Upper Freeport limestone from 15 to 20 feet above 
the Lower Freeport coal. This relation between coal and limestone 
has been maintained for the last 25 miles at least, as will be seen by the 
sections that have been already given. A heavy sandstone overlies 
the limestone, a phase of the Upper Freeport sandstone of the general 
scale. 
The valley which we have been following from Juniper’s to the 
Frank coal bank holds a direction a little east of south, so that its fall 
coincides with the dip of the coal, but below Frank’s, the stream turns 
abruptly to the west, and thus runs against the dip of the coal. It 
is here that the mistake has been made which has led to the posi- 
tive identification of the Carbondale and the Juniper coals. No one 
questions that the latter is the seam known as No. 6a to the northward. 
At the Frank mine, the coal has the same level that the Carbondale coal 
has, ? of a mile to the westward, but the dip brings down the upper 
seam in this interval to this level. It must be granted that the required 
dip is in excess of that usually prevailing, but it is not by any means 
without precedent. | 
At Carbondale the Upper Freeport limestone is found at 53 ft. and 
at 60 ft. above the Carbondale coal, but at Frank’s and Juniper’s, the 
same limestone comes in at 17 ft. above the coal. A heavy sandstone, 
the Lower Freeport, covers the Carbondale coal throughout this region. 
The Freeport limestone lies only a few feet above it in many places, in 
which cases the Lower Freeport coal is wanting. It is the resemblance 
of this sandstone to the stratum above the limestone which has helped 
to mislead many as to the true order. The two sandstones often appear 
as one undivided stratum, and yet care enough in examination will 
generally show the place of limestone or coal between the two elements 
that constitute the apparently massive rock. Andrews gives in his sup- 
plemental report an instructive example of the blending of these same 
sandstones in another portion of the field (vol. III, p. 853), and every 
geologist who has worked upon coal measure formations has met with 
similar cases. 
A better guide is found in the Cambridge limestone. There is an 
outcrop of this limestone above the Frank coal, or rather above the 
