with
2,377,946 fine ounces, against 2,036,909 ounces in 1910; Arizona
produced 2,136,121 ounces, against 1,934,363 ounces in 1910; and
California ranked fifth with 864,397 ounces in 1911, against 1,363,668
ounces in 1910. The output of silver from copper ores in Colorado and
Idaho has greatly fallen off in the last two years, but that from
Nevada has increased. The production from Montana is mainly from Butte,
that of Utah from Tintic and Bingham, that of California from Shasta
County, and that of Arizona mainly from Bisbee and Jerome. Of these
districts Bingham alone represents the disseminated type of deposit,
and the silver output from these copper ores is still chiefly from deep
lodes.
LEAD ORES.
The
silver production from argentiferous lead ores in 1911 was 15,596,638
fine ounces, against 15,028,076 ounces in 1910. The output from Idaho
has increased from 5,692,906 ounces in 1909 to 6,479,636 ounces in 1910
and to 7,059,990 ounces in 1911. The output of Utah has decreased from
8,314,766 ounces in 1909 to 6,423,523 ounces in
1910
and to 6,083,877 ounces in 1911. The production in Colorado increased
in 1911, but that from Nevada fell off. The output in Idaho is mainly
from the Cceur d'Alene, that in Utah from the Park City and Tintic
districts, and that in Colorado from Aspen and Leadville. Although much
of this silver production is from argentiferous galena, oxidized
silver-lead ores are still mined at Tintic, Aspen, and a few other
camps.
ZINC, LEAD-ZINC, AND MIXED ORES.
Argentiferous
zinc ores supplied 630,573 fine ounces of silver in 1911, against
755,369 ounces in 1910, the output and the decrease for
1911 being mainly from the Butte district of Montana, where the zinc-mining industry has been making rapid strides.
Lead-zinc
ores furnished 2,460,152 fine ounces of silver in 1911, against
1,968,311 ounces in 1910. Production from this source inÂcreased from
1,228,398 ounces to 1,358,311 ounces in Utah, and from no recorded
output for 1910 to 510,667 ounces in 1911 in Idaho; but it decreased
from 679,500 ounces to 476,049 ounces in Colorado.
Copper-lead
and copper-lead-zinc ores in 1911 yielded 285,006 fine ounces of
silver, against 535,987 ounces in 1910. The production is mainly from
Montana, Colorado, and Utah, in nearly equal quantities. The output
from Montana increased, but decreases were large in Colorado and Utah.
DISTRIBUTION OF PRODUCTION OF GOLD AND SILVER, BY METHODS OF TREATMENT.
In
the Survey report on gold and silver for 1910 figures were first
published showing the distribution of output by methods of treatment.
In
the following table a summary is given of the distribution of the gold
and silver production of the United States in 1911, showing—
1. Total crude ore, tailings, and slags sold or treated in 1911.
2. Crude ore treated in gold and silver mills.
3. Crude ore concentrated, with resulting concentrates.
4. Crude ore shipped to smelters.
5. Old tailings and slags treated.
The last four include recoverable gold and silver content in fine ounces.
