Mineral Point tribune. [volume] (Mineral Point, Wis.) 1854-1858, 1858-05-11
From the Daily State Journal
DEPTH OF THF LEAD VEINS OF WISCONSIN.
NO. III.
by EDWARD DANIELS.

veins.
Mr.. Phillips, very distinguished Eng
ish Geologist, remarks" that. as ren-
eral fact, we cannot doubt the far great
or prevalence of mineral veins in the old :
er IMAM IA the newer rocks. Not one
case is known of a mineral vein being
worked IN any part Of the British Islands
above the new red sandstone. In this
last rock, and in the coal formation below.
only slight traces occur, but veins become
abundant III the mountain limestone, and
IN the older strata. But yet il is probable
that THIS relation of mineral veins to the
age OF deposits, is merely a consequence
OF the more general truth, that their orr
GIN IS from below, and that the metallic
ana sparry matters which occur, as well
as the assures which contain them, are
more abundant near the igneous rocks.
Dale Owen, in his first hasty d" Report
on the Lead Veins of Iowa and Wiscon-
sLn, discusses this point at some leugth.
lie says THE lead ore of Iowa and
Wisconsin IS mined in a rock of some
what greater antiquity than the mountain
limestone which chiefly furnishes the lead
OF England. 1t behooFes US to remember.
however, that the metaIhferous capacity
OF ROCKS depends not so much upon their
age as their Theological character. Thus,
though the lead bearing rocks of England
and America are not strictly equivalent
they are analogous in those point on
winch their productiveness chiefly de-
pendS. And SO far as difference of age
is concerned, the advantage is with the
lead bearing rocks of Amarica.
All other things being equal, the older
the rock or the nearer it approaches the
inferior Igneous rocks, the richer will il
be III metals.
In point Of fact, if we except the prin-
clpal lead region of England, Galena oc-
ours far more richly and frequently in
formations older than the mountain lime
stone, than IN the mountain limestone Il
self. The lead mines of Spain are in
rocks as we'll as our own.
The mighty lead glance veins of Lin
ares occur IN granite. The colapal de-
post OF ore ~ the Sierra de Gador, which
affords $4,000, 600 lbs. of ore in single
year, IS IN a limestone still older than
ours. So also the well known lead hills
of JanarGshire in Scotland. In the noun
talns OF the Hortz, 50 rich III metallic ores,
lead occurs IN immense veins IN the tran
sltlon formation
In Chrlstiana, Norway, it occurs in
mlce slate, of the primary stratifed rocks.
AT Saia, IN Sweden, it forms veins in
primitive limestone.
AT Lozere. ia France, granular and
compact Galena runs through primary
rocks; and in Saxony, it occurs in the
same position.
In fine, l know of hardly any lead re-
gion OF Importance on the European Con-
tinent, which is not older than the noun
tam limestone Of England. So far then,
the comparison of the geological charac-
ter OF the lead regions of our own and
other countries, IS more favorable to those
oI Iowa and Wisconsin, than if the rocks
had proved strictly identical.
There IS one condition Of things in the
district on which | am reporting, which
may be considered unfayorabIe to the
prospects Of 4 mining country. It is the
absence Of igneous rocks. [ mention .his
as an exception TO a very general rule.
9 1t IS not" says Phillips, "on account
OF the great antiquity of the states of
Cornwall, that they are 50 very metaIlif-
erous, but on account of their proximity
to the granite. The rocks of ireland, un-
disturbed by any great exis of movement,
are very slightly metalliferous, while the
same rocks, where they have been up
heayed by igueous rocks from below,
abound IN metallic veins of various kinds.
There the most general point Of view. in
winch VEINS present themselves, Is III de-
pendenCe upon the sources of subterran-
can heat. Ia the rocks nearest these
sources, they are most numerous and va
riable."
But 1t must not be forgotten that this
district has been only hastily surveyed
and the mining has thus far been very
superficial. We must not conclude be-
cause no .rappean or crystalline rocks have
been found, that they do not exist there.
| incline 10 the belief, from the abundance
Of the metallic ores and the irregularitv
of the dip in The Northern part of the
lead region, that the igReous rocks can
not be far off.
The limited time allowed for the com +
pletion Of this survey, prevented me from
investigating the matter as minuteIy as
could wish. 1t is a subject however, .
which demands the most rigid inquiry,
since in the absence of deep excavations,
1t IS the most important guide to the So
luton of the problem: do the VEINS Of
lead ore after passing the blue fossilifer-
Gus limestone and underlying sandstone,
extend downwaads into the lower megne-
sian limestone z"
Il is worthy of note in this connection
that the lead mines Of Missouri, which
have proved SO rich and productive, are
E~InclpallV In q rock which Is the raolor-
zeal equivalent Of our lower magnetism
limestone.
On visiting these mines, l was surpris-
ed to find them IN a rock resembling IN
charocte- our lower magnetism.
The observations of the Missouri Geolo-
gists have since proved them to be in that
formation.
DIR. Little of the State Geological sur
vey remarks in his able report Of 1854,
" the galena IS so far as my knowledge