Economic Geology, Volume 15Economic Geology Publishing Company, 1920 |
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Halaman 9
... probably more than 7,500 feet , rests unconformably upon all of the three earlier formations . Moffit considers it to be of Upper Jurassic age . It does not occur in the immediate vicinity of the mines and bears no relation to the ore ...
... probably more than 7,500 feet , rests unconformably upon all of the three earlier formations . Moffit considers it to be of Upper Jurassic age . It does not occur in the immediate vicinity of the mines and bears no relation to the ore ...
Halaman 11
... probably to its more brittle nature . The fracturing may be divided into three classes — faults , sheeted zones , and prominent single fissures with- out faulting . There is a certain amount of intermingling of all three ; faults or ...
... probably to its more brittle nature . The fracturing may be divided into three classes — faults , sheeted zones , and prominent single fissures with- out faulting . There is a certain amount of intermingling of all three ; faults or ...
Halaman 15
... probably extended over the vicinity of the mines , although higher than the present surface . It is not known whether the Tertiary volcanics which lie on this surface ever covered the region in the vicinity of the mines , but they do ...
... probably extended over the vicinity of the mines , although higher than the present surface . It is not known whether the Tertiary volcanics which lie on this surface ever covered the region in the vicinity of the mines , but they do ...
Halaman 18
... probably obtained from impurities of the lower limestone country rock . 17 11.68 per cent . of this copper is in the form of copper carbonate . greenstone are most numerous but as yet have resulted in 18 ALAN M. BATEMAN AND D. H. ...
... probably obtained from impurities of the lower limestone country rock . 17 11.68 per cent . of this copper is in the form of copper carbonate . greenstone are most numerous but as yet have resulted in 18 ALAN M. BATEMAN AND D. H. ...
Halaman 36
... probably as a result of the mineralizing solutions . But beyond the limits of the ore similar recrystallization occurs , and zones of calcite are common in vari- ous parts of the Chitistone formation , as would be expected in a ...
... probably as a result of the mineralizing solutions . But beyond the limits of the ore similar recrystallization occurs , and zones of calcite are common in vari- ous parts of the Chitistone formation , as would be expected in a ...
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Edisi yang lain - Lihat semua
Istilah dan frasa umum
appears bands basin bodies Bonanza bornite calcite carbonate cassiterite cent chalcedony chalcocite chalcopyrite Cherty Chitistone chlorite coal Cobalt concentration contain copper country rock covellite crustification crystalline crystals deposits depth diabase district dolomite drilling Duluth gabbro east Mesabi enargite erosion feet field fissures flat fault folding formation formed fractures gabbro Geol geologist glauconite grains granite greenstone Gunflint horizon igneous inclusions indicate iron irregular Jumbo Kennecott Lake limestone lower magma magnetite marl massive material ment microscopic minerals mining nitrate occur oil and gas origin outcrop oxidation parallel pay sand places planes Plate porphyry present probably production pyrite quartz recrystallization region relation replacement salt schist schistose sericite shale silica silver slopes solutions specimens sphalerite structure sulphides supergene surface temperature tennantite tetrahedrite thickness thin section tion U. S. Geological Survey Upper valleys vein quartz veinlets vertical volcanic wall rock zone
Bagian yang populer
Halaman 247 - ... lode, in the judgment of geologists. But to the practical miner, the fissure and its walls are only of importance as indicating the boundaries within which he may look for and reasonably expect to find the ore he seeks. A continuous body of mineralized rock lying within any other well-defined boundaries on the earth's surface and Opinion of the Court — Mr. Justice Field. [August, under it, would equally constitute, in his eyes, a lode.
Halaman 297 - Quantities sufficient to justify commercial exploitation are deemed to exist when the quantity and quality of the oil or gas so recovered from the well are such as to afford a reasonable expectation of at least returning the capital invested in such well through the sale of the oil or gas, or both to be derived therefrom.
Halaman 245 - ... extended downward vertically, although such veins, lodes, or ledges may so far depart from a perpendicular in their course downward as to extend outside the vertical side lines of such surface locations. But their right of possession to such outside parts of such veins or ledges...
Halaman 479 - ... derived from augite, or perhaps from olivine, and percolating waters again come into play. Thus the various productions of glauconite and celadonite become the results of a single process, which is exactly equivalent to that in which potassium compounds are taken up by clays. The observation of L. Cayeux that glauconite is frequently present in arable soils, in all conditions from perfect freshness to complete alteration into limonite, suggests that perhaps the formation of the species is one...
Halaman 315 - I cannot fall out or contemn a man for an error, or conceive why a difference in opinion should divide an affection; for controversies, disputes, and argumentations, both in philosophy and in divinity, if they meet with discreet and peaceable natures, do not infringe the laws of charity. In all disputes so much as there is of passion, so much there is of nothing to the purpose; for then reason, like a bad hound, spends upon a false scent, and forsakes the question first started. And this is one reason...
Halaman 247 - The use of the terms vein and lode in connection with each other in the act of 1866, and their use in connection with the term ledge in the act of 1872, would seem to indicate that it was the object of the legislator to avoid any limitation in the application of the acts, which a scientific definition of any one of these terms might impose. It is difficult to give any definition of the term as understood and used in the acts of Congress, which will not be subject to criticism. A fissure in the earth's...
Halaman 247 - We are of opinion, therefore, that the term as used in the acts of Congress is applicable to any zone or belt of mineralized rock lying within boundaries clearly separating it from the neighboring rock.
Halaman 247 - It includes, to use the language cited by counsel, all deposits of mineral matter found through a mineralized zone or belt coming from the same source, impressed with the same forms, and appearing to have been created by the same processes.
Halaman 301 - Having more evidence for than against; supported by evidence which inclines the mind to believe, but leaves some room for doubt ; likely ;" and in common acceptation the word implies, when applied to a condition which may be supposed beforehand, that we know facts enough about the condition supposed to make us reasonably confident of it; or, at the least, that the evidence preponderates in its favor. In civil actions it...
Halaman 245 - But their right of possession to such outside parts of such veins or ledges shall be confined to such portions thereof as lie between vertical planes drawn downward as above described, through the end lines of their locations, so continued in their own direction that such planes will intersect such exterior parts of such veins or ledges.