The Madisonian. [volume] (Washington City [i.e. Washington, D.C.]) 1837-1845, 1841-04-20
MfsreIlaufnus.
THE LEAD MINES OF IOWA.


THE LEAD MINES OF IOWA.
A small volume entitled Sketches Of Iowa,
by John b. Newhall, has just been given to the
public. II is full of interesting information with
respect to Iowa and our Western Country gene
rally. We extract from il the following account
of the Lead Mines and Mining in Iowa:
GAIENA (sulphurate of ead) may be divided
into three classes or descriptions, according TO
the relative per cent. of the pure metal yielded
by each
The first class is that which lies nearest the
surface of the ground and, consequently, the
first species of ore discovered 1t is known
among the miners by the name OF ash mime
rail- on account Of its being covered with a
substance in appearance similar to white ashes.
This substance appears to be a carbonate of the
protoxyde Of lead. It's generally found in small
bodies at the depth of six or eight inches from
the surface, and Immediately under the first
strata Of soil, and lying in horizontal sheets OF
about one inch and half in thickness.
The fact Of this ore lying SO near the surface
of the ground, in which situation 1t must neces-
sarly come in contract with more or less oxygen
or atmospheric air, readily accounts for It's beng
covered with this 'ashy' substance.
This description of ore is generally found on
or near the highest elevation Of the bluffs, and
by the horizontal position of the sheets, the outer
edge becomes exposed 10 view by continued
."ss e :. IS -. and thus leads to the DIS s.
ore, therefore, was easily discovered when the
mining region was first explored, as the pioneers
might, by poughng or spading up small gar
den, open TO the sight large pieces OF the spark
ling ore.
This species Of lead is, for two reasons, en-
titled to be called the first class: first il yields,
on an average, from eighty to eighty-fve per
IL. al.
of ore, at the highest, yield but about seventy
FIVE or seventy-six per centum, and sometimes
but from forty to fifty
Secondly because il was the first species dis
covered and the only sort known to the Indians
previous to the settlement of the country by the
whites; it being of so pure quality that they
were enabled to run it into bullets and ornaments
with the simple aid of therog fires. It's obtain
ed with the least expense of any Of the varic-
ties of ore, although never found in as large bo-
dies as that which lies farther from the surface,
the size of the sheet seldom, if ever, exceeding
$4,000 pounds weight, and most generally Of
about one-tenh that size
The second class of lead ore may be found in
a soft clay, Immediately above the secondary
rock at depth ranging from ten TO forty feet
beneath the surface. 1t may be proper, per
haps, to state to the reader that the formation OF
the earth in the mining region is composed of a
more mixed combination OF earths than almost
any other part of the globe-lying in regular
strata above the primary rock. In sinking a
shaft, (Which is generally Of as small dimen-
sions as convenience will allow, being about
three and a half to four feet in diameter,) the
miner finds, for the first two or three feet, soft
light-brown clay, which, at the depth of three
feet, gem, rally becomes mixed with small pieces
of white flint, and, as he descends, the flint
gradually increases in size; the clay, at the
same time, becomes of a darker red, or .ochreish
color. AT the depth of FIVE feet, he finds the
flint changed into deep blue color, and formed
into regular sheets Of about two and half or
three inches in thickness, generally about three
sheets living horizontally above each other, and
separated by strata ofreddish clay Of about three
inches in thickness. After sinking through these
strata of flint, the clay becomes of brighter
red, and mixed with kind OF spurious iron ore,
frequently in so great a proportion as to carry
the appe arance of a solid bed Of rust or oxyde
of IRON This strata varies in thickness more
than that Of any other, being frequently eight
feet thick, and at others entirely disappearing;
below this strata lies soft dark-brown clay,
sometimes mixed in varegated manner with
small strea ks of green, red, blue, white and vel
low clay. The yellow strata OF clay has the APP
pearance Of the protoxyde of lead, and often is
the only colored clay found in the strata as
above mentioned in which case il is frequently
eighteen inches in thickness, and is more regu-
lar than the other colors. Iheclay al thls uepth
is of very moist nature, and is found Imme,
diately above the sand or secondary rock, and
internlingled with ii. About eighteen inches
above the rock is found what is called by the
miners chunk mineral deriving its name from
the form in which il is found, having the APP
pearance of being thrown together without regu
larty, being found in chunks of no regular shape
varying in size from half ali ounce weight TO
1000 pounds. This species If mineral IS Tree
from every substance but sulphur, which 1t con.
tans in greater quantities than the lash mineral,
and consequently yields less per centum oil the
metal the average being about seventy-hve per
cent this ore, however, is found IN large DO
dies, sometimes intermixed with cay Tor me
thickness of eight feet, and. from the soli-
ness Of the clay, is taken from the earth WIN
great facility When the miner has sunk nus
shaft TO the bottom Of the mineral, he drifts eaeh
way from il, by digging out the earth Tor the