THE IRON ORES. 419 
Feet. 
Gb SHANE IiaBloghore= { Tec M plsok Main block, Upper block ......... 258 
Interval, 12 feet. 
MEE SOTO LOCKION Clacton eae eco tee cose es a cen slsccaoule sees ceeecrcocsiesscsssbcentesesee nets 246 
Interval, 38 feet. 
Lower Mercer ore. 
Interval, 40 feet. 
TSN Fes Tibet oro { Blue Limestone block, Lower block ..... Ladi ae 208 
By JECIEP COG==LIEYS GD 6009000000000000000900000000000 c000000D000005000000N00"500080000000000 168 
Interval, 78 feet. 
4. Lincoln ore—Covering Blue ore, Thompson ore, Kidney ore, etc........ 90 
Interval, 60 feet. 
Blackband ore—Sharon horizon veeeeeceeseeeesceeeesceeesseeeeeuns sonesaeeaeaeeuers 30 
Interval, 30 feet. 
Guinea-fowl ore—Conglomerate horizon 
(1. Block ore of Maxville limestone. ) 
The measurements are longer here than to the northward. The 
one ore to be added to the series is the block ore (No. 1), that is borne 
by the Maxville or Sub-carboniferous limestone. South of the Ohio 
River it becomes more regular and valuable, and is known as “lime- 
stone ore.” It is of small account in Ohio, being seldom worked, 
except as an accessory element when the limestone is quarried or mined 
for furnace use. Harrison township, Scioto county, and Hamilton 
township, Jackson county, are the only localities that have produced 
any considerable amount of it. Its quality is good and its volume fair 
for a block ore, the thickness ranging from 4 to 8 inches, but the lime- 
stone horizon is itself one of the most inconstant of the series, and the 
ore does not extend beyond the limestone. 
Its place in the series, when present, is but a few feet below the 
Conglomerate horizon, which makes the base of the series given above. 
The Guinea-fowl ore (No. 2 of the section) has already been 
characterized, and requires no further discussion. It is a showy but 
worthless deposit. Its volume is good, reaching a maximum of 3 feet, 
but its quality excludes it from furnace supply. It carries, in addition 
to all the chemically combined silica of the ore, a large percentage of 
sand and quartz pebbles. Its place is upon the upper surface of the 
Conglomerate. It doubtless lacks persistency, as the stratum that bears 
it is very unsteady. | 
This section is mainly occupied by block ores, as has already been 
