600 GEOLOGY OF OHIO. 
Per cent. 
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The quarry which has been the most important is located about 
half way between Waverly and Piketon. Here the stone forms a mas- 
sive bed 8 feet in thickness. The same ledge has been worked along 
the valley on both sides of the Scioto river for 10 0r 12 miles. That 
quality of stone still remains in easy reach, though some of the quarries 
have already yielded all their brownstone to the market. The depth of 
cap-rock to be removed in these quarries nowhere exceeds 16 feet. 
Allthe ravines that reach the Ohio valley below Portsmouth for 20 
miles disclose a large amount of excellent building stone, but in the 
ravines that are found from 2 to 4 miles below there is a horizon dis- 
closed that lies low enough to be easily reached, and that is naturally 
covered by an easily-eroded cap, so that a very considerable amount of 
building stone has been found readily accessible. This horizon is at 
about the middle of the sub-Carboniferous system in Ohio. 
The Portsmouth quarries have been worked since the first settlement 
of the Ohio valley. During the last fifty or sixty years a great number 
of separate quarries have been opened, but all on the same horizon. 
When the stripping becomes heavy a slight change in location is made. 
The land is considered of no great value for any other than quarrying 
purposes. Some locations prove better than others, and these are being 
worked more systematically of late years. 
At the quarry of Messrs. Reitz & Co. the stone occurs in layers 
from 6 to 24 inches in thickness. These courses are frequently sepa- 
rated by an inch or two of shale. Joints do not occur frequently to 
interfere with the systematic working of the quarries. For flagging the 
stone is unequaled in the Ohio valley, as it wears evenly, always gives 
foothold, and is in every way satisfactory. It is well adapted to sawing, 
and is used quite extensively for general building purposes. The 
material finds its principal markets along the Ohio valley, through Ohio, 
