The Arizona sentinel., 1879-03-29
ARIZONA SENTINEL.
Prospecting.

frequently asked for, and will, no doubt,
interest a number of our readers:
1. Examine the gravel and boulders Of
the mountain streams and note carefully
the structure and character of the gravel
wash This will reveal the geological
formations that are intersected by the
stream. Try the sands at the head of the
gravel bars for free gold, or for any crys-
talzed minerals, etc. If the structure OF
the quartz boulders or other vein-stones
are favorable, go up the stream until the
geological zone is found that has pro-
duced the quartz or other metal-bearing
minerals. Then follow the supposed met
al-bearing zone on its line of strike, and
make especially careful examinations
wherever eruptive bikes are found inter
secting the formation.
,. When lode or vein is found, note
carefully its relation to the country rock,
especially any differences in the opposite
walls of the vein. Then follow it on the
line of out-crop, and note carefully those
points where the best ores are seen, so us
to determine the position OF the best ore
chutes before making any location on the
lode.
8. The first work should consist Of
shallow cuts across the lode at intervals
Of so to 100 feet, or, if the vein is small
and partially covered by soil aid debris, a
trench along the line of out-crop is pre-
ferable. If the surface-tracng is salts
| factory, and the true line of strike has
been determined, then survey your claim
and stake off the boundaries according
to the requirements of the United States
laws
4. The work of exploring the vein I'M
der ground Is the next thing in order.
To do this intelligently, you must select
that point on the line of out-crop where
the best ore is found, then sink shaft on
the lode following the angle OF dip, keep
! ing both foot-wall and hanging-wall eX-
posed If possible. If the lode is TOO wide
! for this to be done, ten follow the best
ore-streall of the vein itself, and at every
fifty feet in depth make cross cuts to The
walls of the vein. After 100 feet deep is
| reached, run levels each way from the
shaft on the line of the vein in order tc
:deterIhine the extent or spread of the
ore-chute or chimney on the horizontal
line. When the limit of the ore-bOdy on
the horizontal line has been ascertained
then sink 100 feet more; and drift right
as before If more than one chimney o
ore is found on the line Of the vein, a shat
should be sunk on it and drifts run Il:
above stated, being careful to confne al
the exploring work within the walls 0
the vein itself. When enough has beer
done to prove the character, size ant
quality of the vein, it will then be time t.
determine the portion, character and eX
tent of the dead work " necessary t.
work the mine to the deep. These queS
tons should be settled by careful survey!
made in the light of all the local facts ant
surroundings, such as the geological
structure Of the country rock, the proba
bic amount of water to be raised, the low
est point of drainage by adit or level, an
the most convenient point for delivery c
the ores to the surface, etc.
The last part of the preliminary e3plc
ration of any mine is to determine, by at
{ tual tests, what are the best methods {
reduction, and the extent and kind Of It
ductior works needed, etc.
5. After all these preliminary fact
have been thoroughly ascertained an
clearly defined, the unavoidable risks {
mining will have been fully met and Owe
come All subsequent Operations are sin
ply matters Of skill and business manag,
ment, and the ca7italizing Of the min
becomes a mere matter Of business detail
The requirements are as follows:
l. The preliminary exploration mus
have ore enOnUh cut and undcr-run {
otherwise exposed, 10 give at least tn
gears lcork for reduction works of an e,
tent sufficient for the average annual GU
put Of ore.
.. The reduction works must be suite
r. for the best treatment of the ore
8. The explorations of the mine mu:
: be pushed ahead Of the extraction of Or
so as to expose at least one ton of ore
new ground Tor every ton extracted froI
the previously explored ground.
4. Before erecting reduction works tn
g., ore exposed In the mine should be S
thoroughly tested as to guarantee a ne
profit sufficient to pay the whole cost {
such works.
5. The mine being well opened, az