Silver and Gold: An Account of the Mining and Metallurgical Industries of the United States |
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Halaman 47
... veins were discovered in 1861 , and subsequently developed to a depth of 500 feet , at Copperop- olis , Calaveras County , maintaining their character for width of vein and grade of ore at lowest levels opened ; but in 1867 operations ...
... veins were discovered in 1861 , and subsequently developed to a depth of 500 feet , at Copperop- olis , Calaveras County , maintaining their character for width of vein and grade of ore at lowest levels opened ; but in 1867 operations ...
Halaman 48
... vein , or , more properly , a series of veins of quartz which has been traced on a longitu- dinal line , with occasional interruptions , for a length of about seventy- five miles , from Bear Valley , Mariposa County , to Amador City ...
... vein , or , more properly , a series of veins of quartz which has been traced on a longitu- dinal line , with occasional interruptions , for a length of about seventy- five miles , from Bear Valley , Mariposa County , to Amador City ...
Halaman 50
... vein of from 12 to 14 feet in width . The quality of the quartz here has improved with each successive level below a ... veins in the granite belt . - In addition to the Mother lode , this region possesses other quartz mines which are ...
... vein of from 12 to 14 feet in width . The quality of the quartz here has improved with each successive level below a ... veins in the granite belt . - In addition to the Mother lode , this region possesses other quartz mines which are ...
Halaman 51
... veins , the quartz occupying only a portion of the space , ( 3 to 9 feet , ) the balance being filled by an accompanying vein matter differing from the country rock , and not found outside of the fissure walls . The whole of this vein ...
... veins , the quartz occupying only a portion of the space , ( 3 to 9 feet , ) the balance being filled by an accompanying vein matter differing from the country rock , and not found outside of the fissure walls . The whole of this vein ...
Halaman 61
... vein- matter here seems to have widened with the expansion of the mountain , and veins are found both on the foot ... vein is 14 feet wide ; 8 feet of this vein - matter is hard white quartz , and 6 feet are a mixture of soft slate and ...
... vein- matter here seems to have widened with the expansion of the mountain , and veins are found both on the foot ... vein is 14 feet wide ; 8 feet of this vein - matter is hard white quartz , and 6 feet are a mixture of soft slate and ...
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50 feet amalgam amount antimony arrastra assay average Bannack base bullion bed-rock bullion Calaveras County California Caņon carbonate cent chemical claim coal commenced company's contains copper cost County course Creek Cupellation December deposits depth developed district ditch drift drill east El Dorado County engine erected Eureka expense extracted feet deep feet in length feet long feet wide furnace galena gangue gold Gold Hill gravel ground Gulch Hill hundred hydraulic inches incline iron labor lead ledge limestone located lode metallurgy metals miles mill miners Mining Company months nearly Nevada opened operations ounces owners placer mines pounds present Professor prospecting quantity quartz quartzite rich River rock San Francisco silver slag slate smelting smelting-works stamps stopes sulphurets sunk supply surface Table Mountain tailings thick tion tons Total tunnel Tuolumne County tuyeres Valley vein width yield