 | John Mason Boutwell - 1905 - 522 Seiten
...sulphide occur around grains of chalcopyrite in the thin section shown in one of the photomicrographs (Pl. XXVII, B). The reason for the decrease in assay values...copper and gold in minor amounts; both the other types arc essentially copper ores with minor gold and silver values. They occur within strong, clearly defined... | |
 | 1905 - 848 Seiten
...then that in the disseminated ores in igneous rock the copper-metals were deposited by hj'drothermal action subsequent to the date of igneous intrusion,...are now undergoing normal superficial alteration. VI. Genesis of the. Ores in Fissures. 1. Character. — The ore occurring in fissures in this district... | |
 | William Harvey Emmons - 1913 - 274 Seiten
...transportation. It appears, then, that in the disseminated ores in igneous rock the copper minerals were deposited by hydrothermal action subsequent to...are now undergoing normal superficial alteration. The Utah Copper Co., which is exploiting the ores of the Bingham laccolith, is said to have developed... | |
 | Geological Survey (U.S.) - 1913 - 272 Seiten
...transportation. It appears, then, that in the disseminated ores in igneous rock the copper minerals were deposited by hydrothermal action subsequent to...are now undergoing normal superficial alteration. The Utah Copper Co., which is exploiting the ores of the Bingham laccolith, is said to have developed... | |
 | Ulysses Sherman Grant, Daniel F. Higgins - 1913 - 800 Seiten
...transportation. It appears, then, that in the disseminated ores in igneous rock the copper minerals were deposited by hydrothermal action subsequent to...are now undergoing normal superficial alteration. The Utah Copper Co., which is exploiting the ores of the Bingham laccolith, is said to have developed... | |
 | William Harvey Emmons - 1917 - 574 Seiten
...then, that in the disseminated ores in igneous rock the copper minerals were deposited by hydrotheruial action subsequent to the date of igneous intrusion,...are now undergoing normal superficial alteration. The Utah Copper Co., which is exploiting the ores of the Bingham laccolith, is said to have developed... | |
 | Geological Survey (U.S.) - 1917 - 572 Seiten
...then, that in the disseminated ores in igneous rock the copper minerals were deposited by hydrotherxnal action subsequent to the date of igneous intrusion,...these sulphides are now undergoing normal superficial aiteration. The Utah Copper Co., which is exploiting the ores of the Bingham laccolith, is said to... | |
 | Geological Survey (U.S.) - 1905 - 522 Seiten
...gold-bearing intrusives. The brilliant tarnish of grains of chalcopyrite indicates a beginning of alteratioh, and thin rims of a dark grayishblack metal about chalcopyrite...amounts; both the other types are essentially copper ores with minor gold and silver values. They occur within strong, clearly denned fracture zones, and traverse... | |
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The reason for the decrease in assay values of copper along certain open and water-bearing fracture zones is doubtless to be found in the wellknown fact that under the action of surface waters copper suffers rapid alteration and transportation. It appears... 