Gold and Silver: Comprising an Economic History of Mining in the United States, the Geographical and Geological Occurrence of the Precious Metals, with Their Mineralogical Associations, History and Description of Methods of Mining and Extraction of Values, and a Detailed Discussion of the Production of Gold and Silver in the World and the United StatesJ. Wiley & Sons, 1908 - 727 strani |
Iz vsebine knjige
Zadetki 1–5 od 61
Stran 165
... slate , in a gangue of calcspar . The deposits in the Hartz Mountains are usually intersected by argillaceous shale , a clayey slate , and the gangue is carbonate of lime , though it is some- 1 Min . and Sci . Press , Vol . 80 , p . 148 ...
... slate , in a gangue of calcspar . The deposits in the Hartz Mountains are usually intersected by argillaceous shale , a clayey slate , and the gangue is carbonate of lime , though it is some- 1 Min . and Sci . Press , Vol . 80 , p . 148 ...
Stran 166
... slate in the vicinity of porphyry , and contain besides silver ores , those of gold , copper and lead.1 " Gold may occur in such quantities or in such a state in the rocks as to be indistinguishable . The tellurium minerals of Cripple ...
... slate in the vicinity of porphyry , and contain besides silver ores , those of gold , copper and lead.1 " Gold may occur in such quantities or in such a state in the rocks as to be indistinguishable . The tellurium minerals of Cripple ...
Stran 169
... slate and greenstone ; the Leadville miners find pleas- ure in a contact of limestone and porphyry ; the miners of Homestake want broad zones of quartz and schists , preferring those stained red by iron ; in Silver Reef , Utah , there ...
... slate and greenstone ; the Leadville miners find pleas- ure in a contact of limestone and porphyry ; the miners of Homestake want broad zones of quartz and schists , preferring those stained red by iron ; in Silver Reef , Utah , there ...
Stran 173
... slate and graphite , through which the gold has been disseminated . Other ore is intermixed with talcoid micaceous schist.1 In both cases but a very small part of the gold is free - milling . The so - called “ sapro- lites " of this ...
... slate and graphite , through which the gold has been disseminated . Other ore is intermixed with talcoid micaceous schist.1 In both cases but a very small part of the gold is free - milling . The so - called “ sapro- lites " of this ...
Stran 175
... slate of quite uniform texture , the origin of which was sedimentary . Later came the intrusion of syenite which formed an extremely irregular shaped dike . In the Alaska - Treadwell mine the dike is 420 feet wide , at the Mexican 150 ...
... slate of quite uniform texture , the origin of which was sedimentary . Later came the intrusion of syenite which formed an extremely irregular shaped dike . In the Alaska - Treadwell mine the dike is 420 feet wide , at the Mexican 150 ...
Druge izdaje - Prikaži vse
Pogosti izrazi in povedi
Alaska amalgamation andesite argentiferous assay auriferous average bed-rock blende calcite California Carolina cent chalcopyrite chlorination Colorado Comstock lode considerable copper country-rock County Cripple Creek cyanide cyanide process Deep Mines deposits depth diorite discovered discovery district dollars drift employed extraction feet free-gold furnace galena gangue gold and silver gold production gold-bearing granite gravel gray copper Gulch Hill hydraulic Ibid Idaho igneous rocks inches iron Jour lead limestone located mercury method Mexico mill Mineral Industry Mineral Resources Mines and Minerals Montana Mountain Nevada North North Carolina occur operations ore-bodies ounces output oxide placer mines placers porphyry precious metals Press probably production of gold pyrite quantities quartz quartz-veins Rept River roasting rocks schists shaft silver production Silver-bearing slate sluices smelting solution South stamps stope sulphides sulphurets surface TABLE tellurides tellurium tetrahedrite timber tion tons Total tunnel usually Utah veins width yield zinc