APPENDIX—GEOLOGICAL SURVEY. 407 
said, none will be found. We will pause here for a moment 
and gather up what facts we have discovered. 
The phenomena presented in these belts of mineral land 
cannot fail to lead us to regard them as separate and distinct 
mineral belts. There may be places where strong north and 
south fissures carry the ore deposits out a little farther in one 
place than another, or where small deposits may be found 
along the north and south fissures between the belts. But 
these are exceptions seldom met with. The fact, however, of 
their persistent course, their parallelism, their eastern and west¬ 
ern extension, establishes beyond doubt the fact that they are 
separate and distinct, although closely related, mineral belts. 
In the report of 1862, the grouping of the fissures into 
ranges, and the ranges into districts was noticed, but no effort 
was made to show the relation of these facts to a higher gen¬ 
eralization ; consequently the lead district has been looked 
upon up to this time as a heterogeneous, unsystematized aggre¬ 
gation of mineral ranges. 
But the above facts show that there is a systematic arrange¬ 
ment of the phenomena of the lead district under some natu¬ 
ral law by which it forms itself into a perfect whole; that we 
have a group of fissures forming themselves into a range; a 
group of ranges forming themselves into belts, and a lead dis¬ 
trict composed of four well defined belts of mineral land, run¬ 
ning parallel to each other with about the same eastern and 
western extension. Now the question for consideration is: 
Do these important and well defined relations end here, or is 
there a physical basis which they indicate, and on which they 
rest ? 
If in the light of the lesser facts with which we commenced 
we have been enabled to reduce the phenomena of the lead dis¬ 
trict to a system, let us see if in the light of this generalization 
we can find any evidences of such a basis. 
In astronomy the slightest disturbance of a planet in any 
given point of its orbit is sufficient to turn all astronomical ap¬ 
pliances to that point in the heavens to look for the cause. In 
geology the slightest disturbance of the strata along any 
