THE IRON ORES. 433 
esteemed as a source of iron, but the horizon does not repay extensive 
work in Southern Ohio. 
Yellow Kidney Ore. 
A much more valuable ore, and the only seam of the entire series 
that is worked at a considerable number of localities, is the Yellow 
kidney ore. Its place is 90 to 100 feet above the Ferriferous limestone, 
or from 40 to 50 feet above the ore last named. It belongs to the 
horizon of the Lower Freeport limestone, sometimes replacing it, and 
sometimes accompanying it. The kidneys are found scattered through 
4 to 6 feet of shale, and when all are counted, the aggregate ranges 
from 6 to 10 inches in thickness. The ore is valued as highly as any 
that comes to the furnaces of the district. It can be mined only by 
stripping, and consequently the ore is at its best. The diggings are 
nowhere extensive, but the seam is opened at a great number of places. 
This ore underlies the Lower Freeport or Hatcher coal by a few feet. 
It is most largely worked on Howard and Buckhorn lands, but it is also 
mined in considerable amount by Centre, Olive, Mt. Vernon, Hecla 
and Little Etna Furnaces. 
At 40 or 50 feet above the Yellow kidney, and therefore at 130 to 
140 feet above the Ferriferous limestone, another kidney seam is found 
that has been worked at a few localities on a small scale. It is known 
as the Little Yellow kidney. The quality is good, but its volume is 
too small and its occurrence is too uncertain to render it an element of 
economic interest. It is assigned provisionally to the horizon of the 
Upper Freeport limestone, or possibly to the place of the Buchtel ore. 
Peterson Ore. 
The Peterson or red ore of the Olive Furnace seems to belong to 
the blackband horizon of the northern counties. It is a stratified ore, 
and a coal seam is found directly associated with it, sometimes cutting 
it out altogether. Its elevation is about what the Upper Freeport 
horizon calls for. The section is as follows on Olive Furnace lands: 
TeXZ8Oe INVOICE I BIABISIO ORES) 555500000 04600080500000300000090000000600000900 162 feet. 
iRetersonior red) Ores (V30—143) einen. dccscteessesestassseesssecosscecsseessss 130 “ 
Buff limestone and ore—Upper Freeport .............csceescsees scene 110 “ 
Coal blossom—Lower Freeport .........c.ccscssccesccsseecccscscusceseseecs Oh, 
Coal—reported Middle Kittanning. .................csccccccscsccscseseeees 65 “ 
Coal—Lower Kittanning .............ccccccesssesvcecees Sa seete seehed asta cs us 20 “ 
MerEMenoy Spline RbON ey ccscasrenticrccdssace csdecesnescacdenegs essen issescacen oy 1Ol ut! 
28 Ge 
