Dodgeville chronicle. [volume] (Dodgeville, Wis.) 1862-current, 1871-10-13
MINING DEPARTMENT.

newly discovered mineral region on the
north shore, and the old copper region to
the east of our lines, on the south shore,
there is this difference, land it is an i'm
portant one:) On the south shore it is
what geologist would call cupriferous-
that is, copper is the prevailing metal or
ore. On Silver Islet, on the north shore,
it is gentiferous-that is, silver prevails.
Now, we seldom End silver and copper
pin the same vein, or IN the same mine, or
even along the same belt. / think may
say never, except where cupriferous and
argentiferous belt cross each other. Silver
and lead are usually found together, not
only in the same belt, but in the same
vein. and very often in the same ere. In
deed we seldom find them apart, except
where the vein is in limestone formation,
which seems to be more favorable to the
deposition of lead than silver. In all 9TH
err formations they associate in varying
proportions, as if they were the results of
the same physical conditions.
One other fact in connection with this
plan I wish to notice; that is, the course
Of the vein is north and south. The fol-
lowing is from one who has just visited
the mine: 'The vein runs from south to
north, and is now being worked under the
waters of the lake. running toward the
main land, about 5000 feet distant Work
has also been commenced on the shore,
short distance from the waters edge, with
prospect Of equal success as on the is
let" OF course we do not claim that these
things will prove north and south axis,
running through this region; but regard
them as strong crcumstantial evidence.
With this haSty visit TO the northern
region, let US return to the lead district,
and extend our investigations south with
in those same lines. In connection with
this lead district south, and doubtless
parts of it, are the lead districts of Iowa
and Illinois, conforming to the same east
ern and western boundary lines. How far
this lead district q include the three in
one,) extends south, am not prepared to
say.
| wrote to parties in Galena, ILL.,, some
time ago for information on this point,
but it has not yet arrived. The impor,
tant discoveries we have been making late
ly on the northern boundary and beyond
it. of which there will be a full report
shortly, ought to remind parties in Ill
nois of the Importance Of looking well to
the southern boundary. If that we are
seeking TO establish be true, it is possible
that this lead district may extend further
south than we have any idea of now.
Extending our Investigations further
south we find within our lines the lead
and zinc districts of southeastern Nilsson
ri; also the iron district, including Pilot
Knob and Iron Mountain The character
istic features Of these districts are very
similar to those found within those lines
to the north. Their mineral resources
are Of no ordinary Importance. The lead
mines were worked as far back as 1920,
and are perhaps the oldest lead mines on
the continent.
Further south we find within those
lines, New Madrid, the scene Of earth
quake action in l8ll-12, the course Of
north. If we pause here, at New Madrid,
and reflect upon these commissions OF rs"
ture, the opening chasms the trembling,
sinking earth the ontbursting of water
and mud the arrest of the Mississippi in
its course, and the rolling of its waters
back toward their source,-we are forced
to acknowledge that only sixty years ago
there must have been return of phys:c
al forces which in more ancient times
played along this line. Do they b ar any
relation to those more ancient forces that
produced the gentle undulations and ele
yations of the strata in the mineral dis.
tricts of the Mississippi valley, and the
iron belts still further north? May they
not al belong to the same original line of
volcanic action? And may we not hope
to find eventually that the secret of these
systems of grouping will be found in their
connection with those lines and forces :?
Nothing is more reasonable, or more
CONSTANT with fact and natural law than
to suppose that along those lines where
the action Of these forces have been slow
ard gentle chemical and mechanical
forces, stimulated by heat, should through
vast cycles of time have been filing tho:e
assures and openings in the rock with
the ore in their crystalline form. Waited
the material Of these ores may have been
by affirmation from the heated interior
condensed in water, and taken up in So
luton perhaps. and brought up in the
form Of mineral waters, to the cooling
region Of the earth's crust, where it has
been deposited under the direction of
those laws that make the phenomena of
mineral veins so intricate and peculiar.
Between the phenomena of the mineral
district with those lines that we have been
following and such physical conditions the
relation seem to be natural and it does
not seem to be very difficult to infer the
one from thu other. The Importance of
this question to the lead district cannot be
overestimated. If these relations are
established it will settle beyond doubt the
relation of our mineral veins to the lower
strata, and to physical forces acting from
beneath. JouN MURRIsH.
Esq VIM. Teasdale, of Mineral Point,