476 WISCONSIN STATE AGRICULTURAL SOCIETY. 
masses of the same rock imbedded in the soil, as though they had ploughed 
their way down irom the deposit above them. 
These things would indicate that this deposit of ore and the place in 
which it is found were connected in their origin with physical conditions of 
an eruptive character, and we are in the habit of referring such phenomena 
to eruptions produced by volcanic or earthquake agency. No doubt there 
are similar places in the earth’s crust, produced by such agencies, and the 
deposits of iron ore in connection with them may be referred to such condi¬ 
tions. 
Notwithstanding there are indications here of eruption, there are many things, 
nevertheless, that would lead us to doubt very much a plutonic origin, or one 
connected with volcanic or earthquake agency. The heat necessary to bring 
about such mechanical disturbance, and that must necessarily accompany the 
introduction of matter in a state of fusion, could not fail to produce very dif¬ 
ferent effects on the surrounding strata than what we observe. Especially 
would this be the case with those large pieces of sand rock found in the 
midst of the ore. In fact, the character of the ore, the manner in which it is 
distributed, the fine, beautiful clay with which it is connected, and which is 
often found filling its cavities, are all opposed to this view. 
There are places found in mineral strata, and in connection with extensive 
ore deposits, that our best geologists are in the habit of explaining by pro¬ 
cesses of chemical and mechanical disintegration, acting locally, but along 
lines of physical disturbance, where portions of the rock are dissolved and 
removed, or changed into clays and other forms of -matter, and where the ores 
of the metals are subsequently deposited, and perhaps from the same solu¬ 
tions, by chemical reaction. Water, traversing rocks that are considerably 
fissured, or rocks that are porous and friable like sandstone, holding these 
solvents in solution, is the recognized agent in such processes. 
Many of the deposits of lead and zinc in limestone formations, especially 
magnesian limestone, are referred (and no doubt correctly) to such processes 
in nature. ' And is it not physically possible — that is, possible according to 
these laws of nature — that this deposit of ore at Ironton may be the result 
of a similar process ? Indeed, is it not likely, since it is an established fact 
in chemistry that thermal waters, especially when impregnated with alkaline 
carbonates, will, at a temperature not above 212° F., acquire the power of 
dissolving silica even in the form of quartz or sand ? The geological age, 
relative position, and porous nature of this sandstone, places it in the most 
favorable condition to be acted upon in this way by thermal waters. Without 
adopting this view fully, I submit these facts and views for the consideration 
of those who are now interested in tracing out the phenomena of this inter¬ 
esting district. The ore of this deposit, as well as the “ float” ore of the dis¬ 
trict, is as might be expected if formed under conditions similar to those 
referred to above — the brown hematite, or what would be called in 
strictly scientific language, the hydrated sesqui-oxide of iron, and yields in 
the furnace from 50 to 55 per cent. iron. This is a superior ore of the kind; 
for ores of this class, when called pure, yield, I think, not over 60 per cent. 
