APPENDIX—GEOLOGICAL SURVEY. 
431 
important to us. The cost of coal and the expense of getting it 
to our zinc mines consume a large portion of what the zinc 
is worth when prepared for the market, and consequent^ ren¬ 
der our zinc deposits comparatively worthless. 
This form of the oxide of iron can be obtained along this 
belt, and be prepared as a paint for the market at a very tri¬ 
fling expense, except for labor. It is found in ledges of sand¬ 
stone, drained by deep valleys cutting back into this ridge, and 
exposed in places from 80 to 100 feet in vertical thickness. It 
can be obtained from the ledges without the ordinary expense 
of mining, and separated from the sandstone by water, which 
most of the valleys will supply. The process is simple, the 
expense is trifling, and cost in fuel, nothing. Labor, common 
labor, is all that is wanted to manufacture this into paint and 
prepare it for use. In view of these facts I am disposed to 
think that this belt of mineral land, along which these depos¬ 
its of ochre and oxide of iron are found, will be equally valu¬ 
able, perhaps more valuable, than if it had been another belt 
along which deposits of lead and zinc were found, similar 
to those belts in the lead district already referred to in this 
report. 
As to the origin of these deposits of iron ore along this belt 
there seems to be but one way of explanation open to us. 
The fact that they are found in the lower, as well as in the up¬ 
per sandstone, and that too where it is covered with 150 or 200 
feet of limestone, (as for instance at Mr. Buggies’ place 
on the road from Arena to Dodgeville,) cuts off all chance for 
explanation by surface agencies, such as is sometimes found in 
connection with deposits of bog iron ore. And again, the fact 
that it is found in connection with ranges of fissures and is 
especially rich at their points of contact would indicate a very 
different origin. 
At Centreville, in the township of Blue River, there is a 
rich deposit found in connection with a range of fissures cut¬ 
ting through the bed of sandstone. These fissures may be 
seen at the head of a valley which is evidently formed along 
their line. One of these fissures has a regular wall with what 
