Dodgeville chronicle. [volume] (Dodgeville, Wis.) 1862-current, 1872-02-09
MINING DEPARTMENT.

In my last article referred TO the
peculiar adaptation of the azoic torma
tons at Lake Superior to the iron de-
post there. I want to say here that
what is true of the azoic formations
there, is true of it the world over.
During the deposition of these stra
ia the interior of the earth was not only
the source of con; t.nt emanations OF
iron. but as much so of all the other
metals. 1t was a period in nebular
| condensation when the crust of the
| earth had become too thick and dense
to conduct It's radiant heat into sur
rounding space, hence it was thrown
into those lines of fracture peculiar to
these strata, which were then the safe
ty valves of cooling world.
Who among us that know anything
about mines, or mineral strata, but is
aware Of the fact that the lower silu-
rean rocks are the mineral strata OF the
world? Aud why? Because its lower
members are formed over the azoic
rocks, and over these lines of fracture,
and consequently must have received
these metallic emanations, large por-
ton of which must have been thrown
down by chemical decomposition in its
passage through the assures of these
| rocks, or entered them as impregna-
| tons from solutions that must have
traversed them to greater or less ex-
tent.
Nothing would be more natural than
to suppose that beds Of friable sand
stone like the potsdam, would receive
as appropriations the metallic emmana-
ton of the azoic period, especially
over those lines of fracture through
which they were known to rise, and to
hold them in the forms in which they
are presented to us in this new belt to
the north of the lead district.
If these deposits of iron were found
in undisturbed rocks, where geological
position is thousands of feet above the
azoic formation, man might be mar
doned for looking for their origin in
physical conditions or forces acting
from above. But here in the lowest,
member of the silurian series, within a
few feet of the azoic rocks, and with
the impress of their lines Of fracture
on the rocks before us, it is folly in the
extreme to look for any other origin.
l would ask pardon for dwelling so long
on this subject, made so plain by the
facts presented, but for one thing, and
that is, the relations of these deposits
of the oxide of iron to the deposits Of
the sulphuret, and carbonate Of lead
and zinc in the lead district are so clear
ly defined as to make their common
origin almost certain. II is in fact a
continuation of the same ore district
with iron ore predominating
And inasmuch as these deposits Of
iron ore are found in belts of mineral
land in the lead district, with the same
bearing, and the same eastern and west
ern extension; and inasmuch as these
deposits are found in the sandstone,
both in the upper and lower formations,
and that these beds in the strata under
lying the lead district, are the connec-
ting links between it and the azoic for
nations, it can leave but little doubt,
if any, of the origin, not only Of the
deposits of the oxide Of iron along this
new belt, but of the deposit of other
ores throughout this entire ore district,
a district Of which this oxide belt forms
but small part. Further information
and evidences on this question may be
found in my report of the lead district,
now in the hands of the legislature
and which will soon, | presume, be in
the hands of your readers. J. M.
P. S. You or your composition. made
me say in my article published last
week, what | think I did not say in my
manuscript, and would perhaps read
better if corrected In the first para
graph, instead of bright neao powder it
should read bright red powder; in the
second, instead OF then points Of con
tact it should read these, and instead Of
,ohen the oxide of iron in this form is
not abundan, t it should read aohere the
oxide of iron is most abundant. NJ.
BG- During the last Is months 50,
900 acres of land has been taken in
this land district by actual settlers
| Springfield Times.
RG| The yield of wheat at the
Kansas Agricultural College farm, at
Manhattan, the past season, was forty
three and one-half bushels per acre.