482 GEOLOGY OF OHIO. 
The Hanging Rock Region. 
The Hanging Rock iron region of Southeastern Ohio and North- 
eastern Kentucky is one of the oldest iron smelting districts west of 
the Allegheny mountains, and now one of the principal charcoal 
iron regions in the United States. The title has been given to the 
region from the village of Hanging Rock, in Lawrence county, Ohio, 
near which place, as has already been observed, the industry was begun 
in 1826, and which also was formerly the chief point of shipment for 
the irons produced by the furnaces of the vicinity. The area so named 
is included in a narrow belt of territory, having an extension in nearly 
a north and south direction, with a width on the Ohio River of between 
12 and 15 miles, where Ironton may be regarded as situated centrally 
as regards its east and west limits. In Kentucky this belt has probably 
an extension of 25 or 30 miles to the south, passing through the counties 
of Greenup, Carter, Boyd and Lawrence. In Ohio, extending through 
Scioto, Lawrence, Gallia, Jackson and Vinton counties, to the central 
part of Hocking it has a length northward of the Ohio River of between 
65 and 70 miles, the broadest part of the area resting on the Ohio. 
Within a radius of 25 miles from Ironton, which is about the geo- 
graphical center of the region, is included the most important part of 
its iron industry, both in Ohio and Kentucky. We are concerned 
here, however, only with that part of the area in the State of Ohio, but 
most of the observations concerning the character and occurrence of 
the ores, and the conditions of the manufacture in Ohio apply almost 
equally well to that part of the region in Kentucky. 
The source of the reputation, the wealth and the industry of this 
Hanging Rock iron region are the rich iron ore deposits lying in several 
strata near the base of the Coal Measures, and which extend with great 
uniformity and regularity through the area described. These same 
ferriferous horizons, however, are quite well marked over the entire 
area of the coal fields in Ohio, and in the northeastern part of the State 
are probably represented by the ferriferous horizons of coals No. 3 and 
No. 4, which are in places in the northern part of the State of some 
economical importance. In Northwestern Pennsylvania the belt of the 
celebrated ferriferous limestone has been regarded as the equivalent of 
these same horizons. Ohio has, however, the most important concen- 
tration of iron ore at these levels in the southern part of the State, and 
no very valuable quantities have been found north of the Licking 
