428 
WISCONSIN STATE AGRICULTURAL SOCIETY. 
country covered mostly with timber and underbrush, where 
the tops of the ridges were covered with several feet of clay, 
and their sides hid from the summit to the base with broken, 
decomposed rock, it was not a very easy matter to obtain the 
necessary information to settle the question. 
By marking on a map, however, these ochrey outcroppings 
and their surface indications, in a similar manner as we did 
those noticed in the lead district, I succeeded satisfactorily in 
making out a line of physical disturbance resembling very 
much the other mineral belts. By ochrey outcropping I mean 
those places along the surface that may be distinguished from 
all other places by a reddish, or a reddish-brown clay 
that is almost always found over productive mineral ranges in 
the lead district. Nor is this peculiar to the mineral strata of 
Wisconsin. This peculiar ferruginous feature of the clay is 
the result, no doubt, of the decomposition of the iron or iron 
pyrites found in the fissures of the rock decomposed to form 
the surface clay. 
I found a belt of land strongly marked with these and other 
features peculiar to the surface indications of the belts of min¬ 
eral land in the lead district extending through town seven, 
from the township of Hickory Grove, in Grant county, to the 
township of Cross Plains, in Dane county, a distance of about 
fifty-five miles east and west. This belt varies in width from 
four to six miles. 
The mines of Highland and Centreville, which we have al¬ 
ways looked upon as an exception to the general rule, are 
found on the western extension of this belt, in the townships of 
Highland and Blue River. But so far as we can judge from 
surface appearances, the mineral wealth of this belt will con¬ 
sist mainly in the large and rich deposits of the oxide of iron 
which it seems to contain throughout its entire length. 
Where these deposits appear at the surface, we find the ore 
existing in different states or conditions. In some places we 
find the out-croppings of what seem to be large beds of very 
impure argillaceous or slaty iron ore; affording, however, in 
places, good specimens or purer varieties, which to me, look 
