386 GEOLOGY OF OHIO. 
extreme cases. Generally they do not go down more than half this 
distance. 
The field already worked lies along the West Fork Valley from a 
little below Teegarden’s Mills as far south as Elkton. The southern 
territory has proved the best. It was not found possible to determine 
the percentage of yield in the worked deposits, nor to refer the kidseys 
as they occur to their several sources. Both these questions admit of 
answers, but the answers would require more time than was available. 
The character of the ore is excellent, as is to be expected from the 
horizons to which it belongs. Its use has been mainly confined to the 
Leetonia furnaces. 
3. TRON ORES OF STARK, CARROLL AND TUSCARAWAS -COUNTIES. 
Three varieties of ore, viz., blackband, kidney and block, have 
been already shown to be mined in the area now to be considered. The 
order in which they are named is the order of their importance, but the 
first is the great center of interest and value, and the last is of insig- 
nificant proportions, and moreover is mined only in one of the three 
counties named, viz.; Tuscarawas. 
a. Blackband and Mountain Ore. 
The blackband ore of this area is the most important source of 
iron in Northern Ohio. It is the second ore in general value in the 
State, ranking below the limestone ore of the Hanging Rock district 
alone in this respect. With the last-named ore it disagrees in almost 
every particular of geological occurrence. The limestone ore is both 
steady and persistent, covering hundreds of square miles almost con- 
tinuously with its thin but excellent sheet. The blackband is extremely 
capricious in its occurrence, and treacherous in its development. It 
forms the cap of scarcely more than 50 hills, scattered through three 
counties, and in these hills it ranges from a maximum of 19 feet to zero, 
an acre or two being often sufficient to accomplish the whole range of 
changes. 
Throughout this field it everywhere deserves its name of black- 
band. There is almost always a foot or two of coal, generally poor in 
quality, underlying it, and thin streaks of coal generally extend through 
the ore itself. But whether coal is present in the body of the ore or 
