Custer chronicle. [volume] (Custer City, Black Hills, D.T. [S.D.]) 1880-1890, 1885-11-14
The Mines Around Custer.
CONTINUED from our last.
CROSS ZONES.

It has been the result of our observa-
ton, and we believe it is fact not gen.
orally noticed or understood. that all the
veins or ore bodies that have been
found, large enough and rich enough to
pay, are always found at the crossing of
two ore zones and are the result of such
crossings. This is something that is not
laid down in the books, at least we have
never seen it, or heard of it's being an
nounced in any work on mines or nin-
ing. But being satisfied from our ex-
perience and observation that it is true,
we hereby announce it on our own re-
sponsibility. We, however, doubt if we
can make ourselves plain on this subject
without cuts and drawings to illustrate
our meaning, but will do the best we
can.
First then We must define terms.
What is mineral zone Of ore? 1t is
Tin the sense in which the word is here
used) strip of earth enclosed within
two parallel lines running a greater or
less distance and carrying within said
lines mineral OF any description. Some
times in small veins, sometimes in
seams, and sometimes there are neither
veins nor seams, but the whole forma-
ton, the country rsck, is saturated and
impregnated with the mineral. A zone
or belt mean the same thing, and the
term has been very properly applied to
the Homestake system Of veins in the
Northern Hills. We distinguish zones
from veins in this way. Veins proper
have marked and defined walls Zones
do not necessarily have any walls. A
zone most always contains q vein. Some
wide zones contain many veins, gener-
ally small veinlets or ore seams poor in
mineral until they cross another zone,
when the zone carrying the largest vein
takes precedence, and the weaker zone
becomes feeder to the stronger, and
helps to enlarge, expand and enrich the
vein or veins contained in the strongest
zone. These zones always run at right
angles but the main vein or ore chute,
produced by the combined strength Of
the two zones, may take strike slightly
varying from the direction Of either of
tie zones, until it reaches the side line
boundary of the zone through which it
crosses, when it (that is your main vein
always narrows up becomes pinched and
small and poor and improbable. Thus
the ,eng.h of your ore chute is determin-
ed by the width ofthe cross zone. Your
vein now having crossed one zone, may
continue through the barren country
rock, but receiving no feeders it be
comes so small and poor to be profitable
until it enters another zone or belt,
when the two zones cross and your vein
Immediately begins to widen out and
grow richer, aud will continue so until
that zone is crossed. Another thing, in
following your vein from where it mar
rows to where 1t opens out again you
may Fl nd that the character of your ore
has changed to some extent, for whereas
while passing through the first cross
zone the predominating mineral was
gold, now you are passing through an
other zone and your predominating
metal may be silver or copper, as the
case may be. 1t il all owing to and de-
termined by the character Of your min
eral zone through which your vein
passes.
We desire all miners to peruse the
foregoing closely, as full understand
ing of it may save them great deal of
useless labor, and enable them often to
make a success where another would
make failure. Every miner of long
practical experience knows that he finds
his ore just in the condition we have
described. but perhaps never thought of
counting for it on the principle here
laid down. Rut we have made study
Of it, have watched it close for many
years, and though we cannot cite you to
any authority on the subject to bear us
out, yet We are happy to be able to say
this is 30, simply because We have found
| it 80. Another thing We wish to state
in this connection, each mineral zone
has its own dip, and in consequence
your ore chute, or ore body, will take q
! dip in the vein. For instance your vein
may run north and south and have q
dip to the west, because the zone in
which it is contained has like strike
and dip, this is generally understood
But what we wish to call your attention
to now is, the fact that your east and
west cross zone has also dip, and
should you find your vein dipping west
you will generally find your ore body
dipping south in the vein, as well al
west with the vein. You should bear
this constantly in mind, otherwise yor
may sink through your ore body, ever
while following your vein downward or
its incline, and never know when yor
passed through your rich ore until yor
find the bottom Of your shaft barren
This with hundred other thin, 8 mus
bs constantly watched in working anC
developing a mine. 1t is 80 easy Il
make mistake in mining and 80 ex
oensiye too that il ia not a matter q