Economic Geology, Volume 15Economic Geology Publishing Company, 1920 |
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Halaman 13
... sulphides were deposited in the first , and dragged in the latter , the distinction is often difficult . Conclusions regarding the amount of displace- ment of ore bodies are usually difficult to obtain and have to be judiciously drawn ...
... sulphides were deposited in the first , and dragged in the latter , the distinction is often difficult . Conclusions regarding the amount of displace- ment of ore bodies are usually difficult to obtain and have to be judiciously drawn ...
Halaman 18
... sulphides , with practically no other minerals or gangue matter . The discussion of this feature will be taken up under " Theoretical Conditions . " Types of Deposits . General . In the Kennecott and surrounding districts , copper ...
... sulphides , with practically no other minerals or gangue matter . The discussion of this feature will be taken up under " Theoretical Conditions . " Types of Deposits . General . In the Kennecott and surrounding districts , copper ...
Halaman 21
... sulphide or of several bands with braided structure . At one point there may be three or four bands of sulphide ... sulphides in the walls . The replacement bodies are of three classes : ( 1 ) irregular massive replacement , ( 2 ) ...
... sulphide or of several bands with braided structure . At one point there may be three or four bands of sulphide ... sulphides in the walls . The replacement bodies are of three classes : ( 1 ) irregular massive replacement , ( 2 ) ...
Halaman 34
... sulphides in some places , for occurrences are frequently observed where the rock carbonates have been attacked along their cleavages by veinlets of chalcocite . Only a part of the limestone is recrystallized , for occurrences are ...
... sulphides in some places , for occurrences are frequently observed where the rock carbonates have been attacked along their cleavages by veinlets of chalcocite . Only a part of the limestone is recrystallized , for occurrences are ...
Halaman 35
... sulphide ore . Covellite probably forms between 2 and 5 per cent . of the ore minerals . The remaining sulphides undoubtedly constitute less than i per cent . of the ore . Enargite may be prominent in places and a few stringers have ...
... sulphide ore . Covellite probably forms between 2 and 5 per cent . of the ore minerals . The remaining sulphides undoubtedly constitute less than i per cent . of the ore . Enargite may be prominent in places and a few stringers have ...
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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.