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858
MINERAL RESOURCES, 1914----PART I.
COPPER ORES.
The mine production of silver from domestic copper ores in 1914 was 14,829,828 fine ounces, against 18,250,253 ounces in 1913 and 18,744,661 ounces in 1912. The decrease was largely due to curtail­ment of output of copper at some of the largest properties in the latter part of the year.
The production of silver from copper ores is from the electrolytic refining of Lake and blister copper produced by smelting. The copper ores are mainly sulphides (except the Lake ores of Michigan, which are native metal in amygdaloid and conglomerate matrix), and a greater tonnage contains chalcocite than chalcopyrite or cuprif­erous pyrite. The great disseminated copper deposits of Utah, Arizona, Nevada, and New Mexico are of increasing importance, and the lode deposits of Butte, Mont., have long been famous. The silver tenor of the extensive Chino disseminated deposits of the Santa Rita district, N. Mex., is notably low, but similar deposits elsewhere add large quantities of silver. Copper ores, especially sulphides, are mainly concentrated before smelting. Oxidized cop­per ores, sought for as fluxing ore and commonly smelted crude, still come from the Bisbee district of Arizona and the Tintic district of Utah.
In output of silver from copper ores Montana continued to lead with 8,015,694 ounces in 1914, against 10,311,809 ounces in 1913 and 10,655,055 ounces in 1912. Arizona followed with 2,604,371 ounces in 1914, against 2,885,115 ounces in 1913, and Utah ranked third with 1,726,230 ounces in 1914, against 2,314,348 ounces in 1913. Cali­fornia produced 703,042 ounces in 1914, against 833,672 ounces in 1913. The production of Montana is mainly form Butte, that of Arizona has been chiefly from Bisbee and Jerome, that of Utah from Tintic and Bingham, and that of California from Shasta County. Of these districts Bisbee well represents the disseminated type; Bingham produces from both lode and disseminated deposits; and the remainder produce silver chiefly from copper ore mined from deep lodes.
LEAD ORES.
The mine production of silver from argentiferous lead ores in 1914 was 19,302,081 fine ounces, against 18,629,246 ounces in 1913, a con­siderable increase in 1914 over 1913 and a notable increase over 1912 and 1911. The output from Idaho increased from 7,806,445 ounces in 1913 to 8,697,580 ounces in 1914, but that of Utah decreased from 7,537,361 ounces to 7,350,213 ounces, and that of Colorado from 1,645,186 ounces to 1,532,943 ounces. The yield in Idaho is mainly from the silver-lead ores of the Coeur d'Alene, that in Utah is chiefly from the Park City and Tintic districts, and that in Colorado from Aspen and Leadvifle. Most of the output is from the desilverization of lead bullion from smelting of western ores and concentrates.
ZINC, LEAD-ZINC, AND MIXED ORES.
Argentiferous zinc ores produced 145,264 ounces of silver in 1914, against 86,432 ounces in 1913, mainly as refinery by-products from the smelting of zinc concentrates from Nevada, Montana, and Arizona.