988 resultados para Manganese.


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The area surveyed during project AMC-11-67 was the portion of the Blake Plateau between latitude 30°00'N and 33°00'N and between the 100 to 1000 fathom curves. The survey was conducted from 3 October until 18 October 1967. Survey operations included dredgings, camera and multi-sensor lowerings. A collection of manganese and phosphate concretions as well as coral and sediment samples were examined by the ESSA(NOAA) Atlantic Oceanographic Laboratories. Chemical analyses were conducted at the NASA Manned Spacecraft Center, Houston by Richard A. Laidley for X-Ray Fluorescence Analysis and H. Costello for Atomic Absorption Analysis. Later the whole collection of samples was transferred to the Smithsonian National Museum of Natural History were it is available for study (see, http://mineralsciences.si.edu/collections.htm).

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The Todoroki Mine is situated about 25 kilometers to the south-east of Ginzan railway station in Siribesi Province, Hokkaido. The author analysed an interesting specimen of black manganese-ore which had a fractured surface which looked like that of a broken piece of wood. This new manganese mineral was studied in its form, physical properties and chemical composition. The author later named this mineral form as "todorokite".

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Bog manganese was long ago reported from various places in Columbia county (1:54) and it seemed well to reexamine these occurrences. According to W. W. Mather in his report of the First District Survey, 1836-42, " in the counties of Columbia and Dutchess 50,000 tons of manganese could be procured without any great expense, if carefully prepared." He also stated that some of the bog manganese showed on analysis as high as 68.5 per cent manganese oxide and less than 5 per cent silica. At the direction of the State Geologist the writer has devoted most of the summer of 191 7 to this work. The results of this investigation, though not in any way confirming the quantitative results of Mr Mather, are herewith published as a matter of record and as an account of the manner of the occurrence and the genesis of postglacial bog manganese.

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Manganese nodules from the Campbell Plateau and Macquarie Ridge have been chemically analysed and their compositions compared with other Pacific nodules. No significant differences in composition are apparent. Foraminifera from nodule nucleii are late Tertiary or Quaternary, indicating the late geological formation of manganese nodules in this region. Nodule formation may be related to late Tertiary or Quaternary submarine volcanism.

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This Monograph on Deep-Sea Deposits forms the penultimate volume of the Official Reports on the Scientific Results of the Challenger Expedition. The work connected with the examination and study of the samples of Deep-Sea Deposits, and the preparation of this Report for the press have occupied a very large part of the author's time and attention for nearly twenty years, and his colleague, Professor A. F. Renard, has also given much of his time to the same studies during the past fourteen years. They hope that the completed work may be regarded as an interesting contribution to our knowledge of the ocean, and prove useful to a large number of scientific men, as it is the first attempt to deal systematically with Deep-Sea Deposits, and the Geology of the sea-bed throughout the whole extent of the ocean. There are three Appendices to the volume, the first containing an explanation of the Charts and Diagrams; the second a Report on the Analysis of Manganese Nodules, by John Gibson, Ph.D., of Edinburgh University; and the third Analyses of Deposits and materials from the Deposits by various analysts.

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Deposits of manganese ore have been found in five of the six provinces of Cuba and have been reported from the sixth. Only Oriente and Pinar del Rio provinces have more than a few known deposits and only the deposits of Oriente have yielded any appreciable amount of ore. In this area the Cobre formation, of late Cretaceous(?) to middle Eocene age, overlies the Vinent formation but their stratigraphie relations are unknown. The Cobre overlies unconformably the Habana(?) formation. The Cobre formation consists of andesitic, basaltic, and dacitic tuff, agglomerate, and lavas with minor amounts of marine clastic and limestone deposits, and a prominent limestone bed, the Charco Redondo limestone member, at the top of the formation. All productive manganese deposits of Oriente are in the Cobre formation, usually within a few tens of meters above or below the base of the Charco Redondo limestone member.

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This chapter discusses the formation and distribution of some metals in ocean-floor manganese nodules in the light of the observed data in the literature and thermodynamic and kinetic considerations of the oxidation of metal ions in the oceanic environment. There are, in general, two major schools of thought on the mechanism of incorporation of the minor elements such as nickel, copper, and cobalt with the major elements such as manganese and iron. One is the lattice substitution mechanism and the other the adsorption mechanism. If the mechanism is lattice substitution, extraction of the metal ions is not possible unless the lattice of the major elements is first broken and exchanged with other ions from the bulk solution. Consequently, the leaching behavior of minor elements should display a very close relationship with that of major elements.

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Chemical, x-ray and other data are given for todorokite, (Mn, Mg, Ca, Ba, Na, K)2.Mn5O12.3H2O, from Charco Redondo, Cuba, Farragudo, Portugal, and Hüttenberg, Austria. Additional localities at Romanèche, France, Saipan Island, Bahia, Brazil and Sterling Hill, New Jersey, are noted. Delatorreite of Simon and Straczek (1958) is identical with todorokite.

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Iron-manganese nodules from the ocean floor have been extensively studied. But, because of the fine grain size of the particles of the nodules, structural identification by X-ray and electron diffraction techniques is difficult and the mineralogy of the iron oxide phase has not been well characterized. The observation of the Mössbauer spectrum-in which each nucleus absorbs gamma-rays independently-is not limited by particle size in the same way as is the observation of Bragg peaks in diffraction measurements, in which radiation must be scattered coherently from a large number of atoms. The magnetic hyperfine splitting in the Mössbauer spectrum of magnetic materials is affected, however, when the particles are so small that they become superparamagnetic. We describe here an investigation using the 57Fe Mössbauer effect of two iron-manganese nodules in which the iron oxide phase could not be detected by X-ray or electron diffraction.

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Manganese deposits are abundant in various places in the Oshima Peninsula southwest of Hokkaido. This is particular the case of Todoroki Mine situated about 25 kilometers to the south-east of the Ginzan railway station in Siribesi Province. It consists of manganese beds intermixed with a tertiary volcanic tuff complex overlaying granite.

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The determinations of the radioactivity of a series of ferro-manganese concretions of the seas and lakes of the U.S.S.R. (especially of the Kara Sea and lakes of Karelia) have brought out certain facts which make possible the determination of the age of the concretions by the content of radium in its different layers.