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31.
G. N. Baturin 《Doklady Earth Sciences》2006,407(2):330-334
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G. N. Baturin 《Lithology and Mineral Resources》2002,37(5):412-428
The behavior of molybdenum and manganese is studied in phosphorite samples from shelves, seamounts, and islands of the ocean. In shelf phosphorites, molybdenum and manganese contents are 2–128 and 12–1915 ppm, respectively, while the Mo/Mn ratio ranges from 0.004 to 4.5. Phosphorites from oceanic seamounts impregnated with ferromanganese oxyhydroxides contain 0.84–14.5 ppm of Mo and 0.1–17% of Mn. The Mo/Mn ratio ranges within 0.0008–0.004. Phosphate-bearing ferromanganese crusts overlying the seamount phosphorites contain 54–798 ppm of Mo and 10–20% of Mn; Mo/Mn ratio varies within 0.002–0.005. Corresponding values for most island phosphorites are 0.44–11.2 ppm, 27–287 ppm, and 0.008–0.20, respectively. Phosphorites from reduced environments are characterized by a relative enrichment in Mo and depletion in Mn, whereas the Mo/Mn ratio reaches maximum values. The ratio decreases with transition to suboxic and oxic conditions. Molybdenum content in recent shelf sediments is commonly higher than that in authigenic phosphorites from these sediments. Recent phosphorite nodules from the Namibian shelf become depleted in Mo and Mn during their lithification, but Pliocene–Pleistocene nodules of similar composition and origin from the same region are enriched in Mo and characterized by a variable Mn content. The higher Mo content in phosphate-bearing ferromanganese crusts is a result of coprecipitation of Mo and Mn from seawater. Nonweathered phosphorites on continents and phosphorites from oceanic shelves are largely enriched in Mo with the Mo/Mn ratio ranging from 0.01 to 1.0. This is an evidence of their formation in reducing conditions. 相似文献
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Using some uranium deposits and recent U-bearing sediments as examples, it is shown that all U-bearing rocks are characterized by an association of organic matter and calcium phosphate, irrespective of the quantitative relationship between these components. A considerable proportion of these components was delivered into sediments with remains of marine planktonic and nektonic organisms. Along with organic matter, calcium phosphate played a significant role in uranium concentration. This is related to a high sorption ability of the calcium phosphate. Uranium accumulated during diagenesis as a result of diffusion exchange between bottom and interstitial waters. The combination of anoxic bottom environment with high bioproductivity in upper aerated waters, a typical phenomenon in oceanic upwelling zones, is the most favorable factor of uranium concentration in the sedimentary process. This determines the stable paragenetic association of organic matter, phosphorus, and uranium in marine sediments, such as black shales and organogenic phosphate deposits. 相似文献
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Oceanology - Comparative studies of the geochemistry of bone detritus were performed for the bottom of the Melovoe deposit (south of the Mangyshlak Peninsula; Oligocene–Miocene) and for the... 相似文献
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G. N. Baturin V. T. Dubinchuk G. I. Ivanov A. I. Siraev 《Doklady Earth Sciences》2014,458(2):1191-1196
Three samples of Fe-Mn crusts overgrown on the surface of rocks are studied from the Mendeleev submarine rise located in the northern subpolar part of the Chukchi Sea. A massive crust up to 4–5 cm thick consists of an upper dense and lower denser layers similar in composition to the main one and contains 31–37% FeO and 11–13% MnO. Thin crusts and films are depleted in both components. Fe-vernadite is a major mineral of the crusts. The comparison of the major and trace element composition of the crusts with oceanic and marine nodules and hydrothermal crusts shows that they are mostly similar in composition to the nodules of the Bering Sea and are significantly distinct from the oceanic hydrothermal crusts. A small inclusion of the Pt-, Pd-, and Ru-rich (up to 1–2%) rock in one of the thin crusts points to the possible role of igneous rocks as a source of precious metals. 相似文献
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Avdyushev V. A. Bordovitsyna T. V. Baturin A. P. Bakhtigaraev N. S. Levkina P. A. Popandopulo N. A. Saleiko K. V. Tomilova I. V. Chuvashov I. N. 《Solar System Research》2022,56(5):327-337
Solar System Research - The results are presented of a numerical simulation for the motion of a group of geosynchronous objects from positional observations obtained with the unique Zeiss-2000... 相似文献
39.
According to the geochemical analysis, the carbonaceous sediments of the Baltic Sea??s deep basins containing 3?C5% Corg are enriched with some metals such as Cu, Mo, Ni, Pb, Zn, V, and U as compared with the shallow-water facies of the Bay of Finland. These metals are also concentrated (against the background values in the clayey rocks) in ancient carbonaceous shales, where the average Cu and V contents are slightly higher and that of Mo, Pb, and Zn lower than in the deepwater carbonaceous sediments of the Baltic Sea. In addition, the carbonaceous sediments of the last basin are enriched, although less notably than the ancient shales, with Ag, As, Bi, and Cd. These data confirm the previous assumptions that the carbonaceous sediments accumulating now in seas and oceans may be considered as recent analogs of ancient metalliferous shales. 相似文献
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G. N. Baturin 《Lithology and Mineral Resources》2009,44(5):411-426
Distribution of the major and trace elements in ferromanganese nodules, which are buried or exposed on the seafloor, and in host sediments was studied in ten concretion/sediment pairs by various physical and chemical methods. It has been established that, in addition to Fe and Mn, a limited number of the major and trace elements (P, Ca, Sr, Ba, Mo, Co, Zn, Ni, As, Pb, Sb, Tl, U, W, Y, and Ga included) is accumulated with a variable degree of intensity (relative to sediments) in the concretions. As compared to host sediments, the maximal content of Mn in concretions is 100 times higher, whereas maximal contents of all other elements listed above vary from more than one to 10–20 times. Manganese and, to a lesser extent, Ba and Sr are concentrated in the buried concretions. Other elements are primarily concentrated in concretions exposed on the sea-floor. The occurrence mode of concretions and compositional data on interstitial water suggest that metals in the concretions were derived from seawater and suspended particulates, in addition to sediments. Burial of concretions in the sediment pile is accompanied by the alteration of their composition, accumulation of Mn (relative to Fe), and loss of several associated metals. 相似文献