Economic Geology, Volume 15Economic Geology Publishing Company, 1920 |
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Halaman 570
... sericite , imbedded in a finer grained matrix of quartz and orthoclase . There is considerable chlorite and sulphides . Silici- fication has occurred throughout the rock and small bands are present where all the minerals composing it ...
... sericite , imbedded in a finer grained matrix of quartz and orthoclase . There is considerable chlorite and sulphides . Silici- fication has occurred throughout the rock and small bands are present where all the minerals composing it ...
Halaman 571
... sericite , apatite , biotite , chlo- rite , and calcite . The relationships show that the alaskite was thoroughly sheeted before the introduction of the vein minerals , but that minor movements continued up to the time of the depo ...
... sericite , apatite , biotite , chlo- rite , and calcite . The relationships show that the alaskite was thoroughly sheeted before the introduction of the vein minerals , but that minor movements continued up to the time of the depo ...
Halaman 572
... sericite and only subordinately of pure flake molybdenite . The larger masses are commonly slickensided . Erosion in the region has been so rapid that the oxidized mantle at the outcrop of the veins is very thin varying in thick- ness ...
... sericite and only subordinately of pure flake molybdenite . The larger masses are commonly slickensided . Erosion in the region has been so rapid that the oxidized mantle at the outcrop of the veins is very thin varying in thick- ness ...
Halaman 573
... sericite , biotite , and quartz in a mineralized shear zone indicates that the ore has been formed by ascending mag- matic waters , probably at a moderate temperature . CONCLUSION . As yet molybdenum ore has been found in only a ...
... sericite , biotite , and quartz in a mineralized shear zone indicates that the ore has been formed by ascending mag- matic waters , probably at a moderate temperature . CONCLUSION . As yet molybdenum ore has been found in only a ...
Halaman 573
... sericite even in the immediate vicinity of the system of veins , but one - fourth mile up the gulch there is a large area of alaskite more than a mile across which is decomposed to a soft easily eroded rock . The water of the north ...
... sericite even in the immediate vicinity of the system of veins , but one - fourth mile up the gulch there is a large area of alaskite more than a mile across which is decomposed to a soft easily eroded rock . The water of the north ...
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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.