Custer weekly chronicle. [volume] (Custer City, S.D.) 1890-1931, 1901-03-16
The Le.chins 81 Or. in Veins.

commenced to pay particular attention
to it until about 20 years ago. Since
then / haye observed it almost times
without number. 1t 10 significant; and
well worthy:the notice of the prospec-
tor. The water leyel in mines varies to
q great extent with the, seasons. For
instance during series of years when
the SHOWS are deep In the mountains,
and the rains through the spring and
summer are copious and plentiful, the
water level in your vein may stand at
say 40 feet. Then there comes series
of dry years when the creeks and
springs run low or perhaps dry up. 1t
will be noticed then that the water level
recedes, and you may not be bothered
with water to any extent until you sink
to depth OF 80 feet, or perhaps huns
drsd feet below theSsuffare. II is but
natural to suppose that this change, GO
ing on for ages (for the veins are not
formed in day. must have some effect
on the ore in the veins, and TO the close
observer it is plain to see that it does.
We walk over the bills and gulches and
where we stand we call it the top, the
surface of the earth. And 80 it is as we
find it today. But where we stand to-
day might have been deep in the bowels
of the earth thousanl years ago. We
do not know exactly what the erosion
has been. but we know from the eyi.
dences all around US that it has been
heavy. We have a right then to sup
pose that the top of our vein was origin
ally hundreds of feet higher than it is
to-day. The evidence is that these veins
were first filed with mineral solutions,
which under pressure have oozed away
from the great granite dykes and filled
all the crevices, 1t is further in evi-
dence from all appearances, that these
solutions in most cases carried large
excess of iron, mingled with copper,
gold, silver. lead, and in fact all the
minerals which 60 to-rnake up what We
call our ore. Now sulphur we find is an
element which is very bountiful in ma
ture, and it has an affinity for most all
the minerals forming sulphuretts, but
most Of all for iron. 1t is natural to
suppose then that it would combine and
chrystallize most commonly in the form
of pyrite of iron and in lesser degree
in most cases) with all the other min
erals. Sometimes with copper, forming
pyrite of copper, sometimes with sill
yer, forming sulphuret of silver, or with
lead forming gslena, and so on Through
the whole list. Now we will suppose
that your vein was originally filed with
this pyrite, and the water level receded
or sunk40 feet, what would naturally
happen? Why, this pyrite which does
not desolye while it is submerged or
or covered with strong min
eral water will decompose very rapidly
when reached by the oxygen in the at
mosphere and surface waters.
Now, the rains descend upon the
earth, and the water sinks into the earth,
and following the lines of least resis-
tance it flows into the veins and cre-
vices and the iron is decomposed The
sulphur is taken up again in solutions
and combines with the copper, and other
minerals which are most readily de-
solved, and downward it all perculates
until it reaches a place wbere the atmos-
phere can no longer gain access to it,
where it again chrystalisss in the form
of pyrite of copper and other minerals.
Now most of the iron is left above in the
form of iron oxide, and here you have
the Cornishmans gossan rock, or the
miners iron cap. This does not apply
to the hemitite, or specular, or hard iron
carbonate ores, it applies alone to the
sponzy earthly lemonite and porous soft
iron ore. This character of iron ore
bears every evidence of having been in
the form of a pyrite, and having under.
gone process Of teaching, it has been
robbed of some former constituents
which have been carried lower in the
vein, and true to appearance there ia
where we find it. This soft porous iron
Gaping is always the best indication of
copper, and it will generally be found in
the form of yellow pyrite of copper
when water level is reached. But even
this does not prove that your vein will
continue rich clear down to the full ex-
tent of the vein. y You may with depth
pass through your rich zone, (made rich
by the teaching from above,) and come
again into comparatively poor or even
barren zone. And this barren zone may
have become so, by having been leach.
ed out at some stage or previous change
of water level, in which case you may
be fairly sure of again encountering an
other iich zone at greater depth. This
has been found to be so universally the
case that it has given rise to the saving
among old country miners that "the iron
gossan rides proud horse" Gold and
silver do not leach as readily as the
baser ores, and therefore. if your vein is
eyer to be rich in gold it is just as liable
to be so at the surface as at greater depth
Further more your gold Is liable to be
free milling as far down as the iron
which envelopes 1t continues to be oxi-
dized. There are exceptions to this
however, for in case your gold is in
combination with tellurium, with which
it combines intimately, 1t is then a COM
pound which is something vastly differ
ent from metallic gold.
But / am nearing the limit of my
space, and although there is mu6h more
to be said in this connection can not
give it in this issue. / have written
this for the benefit of the prospector.
1t is from one who has grown old in the
business, and one who has observed
closely, and is in the habit of doing his