Arizona republican. [volume] (Phoenix, Ariz.) 1890-1930, 1912-02-04
PRECIOUS METAL MINING IN
CALIFORNIA

The condition Of the mining indus
try in California in 1911, so far as
gold and silver are concerned. differed
little from that Of 1910. according To
Charles c. Yale Of the United States
Geological Survey The state an
nually produces between s19.OOO.O0O
and s2l.0OO.OOO in gold. the variation
being almost entirely due to fluctua-
tons in the water season" When
the snow supply in the Sierra is scant
numerous quartz mills must shut
down for a few months owing TO
lack OF water for power, and there is
little water for washing the auriferOus
gravels of the placers. In 1911 the
mine owners had no cause for com
plant in this matter. There are
about 100 producing mining proper
ties in the state Of California. a little
over half of which are placers.
OF the plaCers the most important
producers are the gold dredges which
yield about 50 per cent Of the placer
gold. or 80 per cent Of the total gold
output of the'state from all sources.
This percentage from dredging opera
tions is slowly but gradually increas-
ing During the last ten years the
dredges in California have produced
nearly SiS.0OO,OOO in gold and also
some silver and platinum.
During 1911 one Of the largest
dredges was burned and others were
sent To- the scrap heap. but several
urge new dredSes were built The
modern dredging machines of the best
type are capable Of handling 100000
cubic yards of gravel monthly. In the
more extensive fields, where numerous
machines are at work. they are work
ing ground of an average recovered
value of u cents a cubic yard. at
working cost Of J.67 cents a yard. and
ground averaging 9.64 cents a yard at
cost of 4.52 cents. The numerous
dredges of high capacity at work in
such fields account for the large total
output In the Yuba river field. now
the most important in the state. the
year 1911 was a record one. as it was
also i'm the Folsom field of Sacramen-
To county. The Oroville field showed
some falling off in yield. AS was to be
expected from the oldest dredging
area in the state. where the best
ground mas Dttn NOIhtu Out
From the deep mines of California
nearly ZOO, 900 tons of ore have been
annually mined and treated. but IN
1911 this quantity WAS reduced, owing
to litigation concerning smelter fumes
in the copper mining industry, which
caused some of the larger copper prop
critics to be closed altogether and
others to be worked on part time only.
This factor is especially important in
the states yield of silver. most OF
which is derived from experimenting
operations, particularly in Shasta
county. The silver output of the state
will show a falling off i'll 1911 in con-
sequence The gold output was al
fected in smaller degree from the
same cause. Most of the gold pro-
duced. however. is derived from sill
iceous ores, of which nearly 1000.
600 tons are annually treated in the
state The deep mines produce near
/ ~ 81 per cent of the gold mined IN
| California each year OF the total
I siliceous ore nearly 100000 tons are
derived from quartz-mining opera =
lions i'm the five mother lode count
ies-Amador. Calaveras. FL Dorado,
Mariposa and Tuolumne. OF these
counties Amador has the largest tom
mage and is also the most productive
| from deep mining. Yuba continues
to be the largest producer of gold
among the counties. owing to the ex
tensive dredging operations carried
| on there.
| According To preliminary figures
compiled by the director of the mint
the gold production in California in
1911 was valued at s2O.31O,9S7. against
$2O,44I.40O in 1910. and the silver out
put was S2.I27.236 fine ouncces. val
ued at s15O0.O55. against 1.791.6OO
| ounces valued at 1867. 800. in 1910.