Mineral Resources of the United States, Parte1U.S. Government Printing Office, 1909 |
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Página 83
... depth after the soft ore has been penetrated , the contact between them being generally quite sharp . The hard ore is characterized by high percentage of lime and low percentage of silica and iron ; the soft ore contains high percentage ...
... depth after the soft ore has been penetrated , the contact between them being generally quite sharp . The hard ore is characterized by high percentage of lime and low percentage of silica and iron ; the soft ore contains high percentage ...
Página 86
... depth . Such deposits extend horizontally over wide areas and are mined from extensive shallow open cuts . The mountain ores are of smaller horizontal extent but of greater depth , having been worked to several hundred feet below the ...
... depth . Such deposits extend horizontally over wide areas and are mined from extensive shallow open cuts . The mountain ores are of smaller horizontal extent but of greater depth , having been worked to several hundred feet below the ...
Página 87
... depth and are composed of a group of more or less connected pockets arranged along the strike of the formation . A deposit may have a length of several miles , through which extent individual pockets may in places reach a width of 75 ...
... depth and are composed of a group of more or less connected pockets arranged along the strike of the formation . A deposit may have a length of several miles , through which extent individual pockets may in places reach a width of 75 ...
Página 88
... depth of clay found associated with the iron is doubtless residual , being de- rived from the weathering of the St. Louis limestone . Abundant fragments of the chert associated with the clay and iron are proof of this origin . The iron ...
... depth of clay found associated with the iron is doubtless residual , being de- rived from the weathering of the St. Louis limestone . Abundant fragments of the chert associated with the clay and iron are proof of this origin . The iron ...
Página 89
... depth than width . They lie along the planes of foliation in the inclosing rocks and in many places conform minutely to the folding and other structures in these rocks . In places the deposits extend along the strike of the rocks for ...
... depth than width . They lie along the planes of foliation in the inclosing rocks and in many places conform minutely to the folding and other structures in these rocks . In places the deposits extend along the strike of the rocks for ...
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Términos y frases comunes
10-stamp mill amounted Arizona average value bauxite bullion cadmium California carbonate Carolina chalcopyrite chromite clay Colorado concentrating mill containing copper Copper Company County in 1908 Creek crude cyanide cyanide plant decrease deep mines deposits district.-The dredge drift feet deep following table furnace Geological gold and silver Gold Mining Company granite hematite hübnerite hydraulic Idaho important increase lead and zinc limestone lode long tons magnetite manganese metals miles mineral products Mining and Milling Mountain Nevada North occur operated ounces of gold ounces of silver output oxide pig iron placer mines platinum pounds of copper pounds of lead production in 1908 production of gold pyrite quartz refined reported rock scheelite schists shipments short tons siliceous silver mills small quantity smelters smelting South steel sulphide Survey tonnage total value treated tungsten tunnel U. S. Geol United Utah veins Virginia wolframite yield zinc blende
Pasajes populares
Página 238 - ... estimated duties for the transportation of the ores by common carriers bonded for the transportation of appraised or unappraised merchandise to properly equipped sampling or smelting establishments, whether designated as bonded warehouses or otherwise. On the arrival of the ores at such establishments they shall be sampled according to commercial methods under the supervision of Government officers, who shall be stationed at such establishments, and who shall submit the samples thus obtained...
Página 238 - ... they shall be sampled according to commercial methods under the supervision of Government officers, who shall be stationed at such establishments, and who shall submit the samples thus obtained to a Government assayer, designated by the Secretary of the Treasury, who shall make a proper assay of the sample, and report the result to the proper customs officers, and the import entries shall be liquidated thereon, except in case of ores that shall be removed to a bonded warehouse to be refined for...
Página 77 - Newfoundland into this country during the year 1907; whilst, according to the statistics published by the Bureau of Statistics of the Department of Commerce...
Página 236 - States as shown by the report of the Bureau of Statistics of the Department of Commerce and Labor...
Página 132 - XLV. 463 pp. 1903. CLEMENTS, JM, SMYTH, HL, BAYLEY, WS, and VAN HISE, CR The Crystal Falls iron-bearing district of Michigan. Monograph XXXVI. 512 pp. 1899.
Página 695 - UDDEN, JA A sketch of the geology of the Chisos country, Brewster County, Texas.
Página 5 - The statistics of the imports and exports of minerals, which form an essential part of the volume, are obtained through the courtesy of the Chief of the Bureau of Statistics, Department of Commerce and Labor.
Página 83 - ... and shale, and is consequently of no possible value; and finally the upper bench itself becomes shaly and carries only a very low-grade ore. The Irondale seam is best developed on Red Mountain between Pilot Knob on the northeast and Lone Pine Gap on the southwest. Southwest of Lone Pine Gap the seam either consists of interbedded low-grade iron ore and shale or else its identity is completely lost. Its soft ore, now nearly all mined out either by surface trenches or slopes, is the best in the...
Página 220 - ... and rolling, but is suitable for copper castings, and a large part of it is put to that use. Lake copper excepted, a comparatively small percentage of the copper output carries such low values in precious metals that, together with the value added to the copper by electrolytic refining, these values will not more than pay for the electrolytic refining of the copper; consequently the output of casting copper is comparatively small.
Página 238 - ... satisfactory bonds be designated as bonded smelting warehouses. Ores or crude metals may be removed from the vessel or other vehicle in which imported, or from a bonded warehouse, into a bonded smelting warehouse without the payment of duties thereon and there smelted or refined, or both, together with...