Mineral Resources of the United States, Parte1U.S. Government Printing Office, 1909 |
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Página 90
... bodies are dis- tinctly pod - shaped lenses , with the longitudinal planes of the pods parallel to the dip of the foliation in the neighboring gneisses and their longer axes conforming with the pitch of the rock structure . Usually a ...
... bodies are dis- tinctly pod - shaped lenses , with the longitudinal planes of the pods parallel to the dip of the foliation in the neighboring gneisses and their longer axes conforming with the pitch of the rock structure . Usually a ...
Página 91
... bodies in the anorthosite are irregular in form and have ill - defined borders . The deposits are of approxi- mately the same age as the inclosing rocks , and both are simply different phases of the same rock mass . The ore consists of ...
... bodies in the anorthosite are irregular in form and have ill - defined borders . The deposits are of approxi- mately the same age as the inclosing rocks , and both are simply different phases of the same rock mass . The ore consists of ...
Página 92
... bodies show remark- ably little metamorphism , and though a few characteristic minerals of contact meta- morphism occur , they are so uncommon as to almost escape observation . The Corn- wall mines have yielded more than 20,000,000 tons ...
... bodies show remark- ably little metamorphism , and though a few characteristic minerals of contact meta- morphism occur , they are so uncommon as to almost escape observation . The Corn- wall mines have yielded more than 20,000,000 tons ...
Página 96
... bodies are bounded by joint planes . The following description of the factors controlling the ore deposition on the Mesabi range is given by Leith : " The agent of the alteration is water , coming more or less directly from the surface ...
... bodies are bounded by joint planes . The following description of the factors controlling the ore deposition on the Mesabi range is given by Leith : " The agent of the alteration is water , coming more or less directly from the surface ...
Página 99
... bodies thus far found seem to be in the form of lenses 1 to 250 feet in thickness , with their longer dimensions parallel to the highly tilted bedding of the series . It is probable that also several parallel or overlapping lenses may ...
... bodies thus far found seem to be in the form of lenses 1 to 250 feet in thickness , with their longer dimensions parallel to the highly tilted bedding of the series . It is probable that also several parallel or overlapping lenses may ...
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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...