AVERAGE TENOR OF SILVER IN ORES, BY MINING DISTRICTS.
The
bulk of the silver production, as shown, is from more widely
distributed sources than that of gold, the placers and mixed ores
playing little part, but the dry or siliceous silver, silver-gold, and
gold-silver ores, the copper ores, and the lead ores contributing more
equally in the output. In the brief summary here given detailed
classification of the dry or siliceous ores is omitted.
A
study of Survey data for 1911 of the mining districts shows that the
average yield of the dry or siliceous ores in ounces of silver per ton
was as follows: 0.013 at the Treadwell mines of Alaska, 0.056 in the
Mother Lode, 0.079 at Grass Valley, and 0.962 at Campo Seco, in
California; 9.050 at Leadville, 24.5 at Crcede, 2.732 at Camp Bird,
2.184 at Telluride, and 0.076 at Cripple Creek, in Colorado; 0.698 in
the Little Rockies, 34.101 at Butte, 12.304 at Elkhorn, and 62.010 at
Flint Creek, in Montana; 29.586 at Fairview, 17.546 at Wonder, 0.324 at
Goldfield, 44.914 at National, 31.660 at Seven Troughs, 0.609 at
Manhattan, 26.877 at Tonopah, and 6.445 (at present) at the Virginia on
the Comstock, in Nevada; 3.629 at Lordsburg, and 10.439 at the Mogollon
(Cooney districts), in New Mexico; 0.350 at the Cornucopia, and 0.47 at
the Cracker Creek districts, in Oregon; 0.087 at the Homestake, in
South Dakota; 19.538 at Shafter, in Texas; 12.838 at Tintic, 8.611 at
Bingham, 0.001 at Camp Floyd (Mercur), and 21.454 at Park City, in
Utah; 4.097 at the Republic district, in Washington; and, finally,
0.028 as an average for all the dry or siliceous gold ores of the
Eastern or Appalachian States. The extremely low average tenor of
silver per ton of many of the districts named is due, of course, to the
preponderance of gold ores, with but small quantities of silver alloyed
with the gold. At the Leadville and Creede disÂtricts of Colorado, in
most of the districts mentioned in Montana and Nevada, at the Mogollon
in New Mexico, the Shafter in Texas, and the Tintic, Bingham, and Park
City in Utah, the relatively high tenor of silver in dry or siliceous
ores is noteworthy.
The
average tenor of silver in fine ounces per ton in copper ores by
districts in 1911 was as follows: 0.92 at the Bonanza and 18.66 at the
Chitina, in Alaska; 1.49 at Warren (Bisbee), 0.33 at Globe, 0.002 at
Gold Mountain (Clifton), 0.101 at the Shannon, 0.306 at the San
Francisco, and 0.030 at the Ray camp, in Arizona; 2.050 at the
MamÂmoth, in California; 21.460 at Leadville, in Colorado; 7.337 in the
Coeur d'Alene, in Idaho; 0.040 in the Michigan mines; 2.209 at Butte,
in Montana; 0.036 at Ely (Robinson) district, in Nevada; 0.005 at Santa
Rita (Chino), and 4.249 at Lordsburg, in New Mexico; 0.22^ at Ducktown,
in Tennessee; 0.124 at the Cactus, 12.619 at Tintic, and 0.247 at
Bingham, in Utah; 25.395 at Chewelah, in Washington; and 0.092 at the
Rambler camp, in Wyoming. The relatively low silver content of the
copper ores of the Clifton, Ray, and Ely districts, and especially of
the Santa Rita district, is notable, as are the relatively high tenors
of silver in the Chitina region, and in the Leadville, Tintic, and
Chewelah districts.
The
average silver content in fine ounces per ton in 1911 in lead ores was
as follows: 25.47 at Tombstone, in Arizona; 32.20 at Keeler, in
California; 7.61 at Leadville and 15.60 at Aspen, in Colorado; 13.98 at
Gilmore, and 2.22 at Hunter, 6.61 at Lelande, and 3.04 at Yreka (the
last three named being in the Coeur d'Alene), in Idaho; 12.65 at Butte
and 70.00 at Flint Creek, in Montana; 9.77 at Yellowpine and
