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1.
E. A. Mamontova E. N. Tarasova A. A. Mamontov M. I. Kuzmin 《Doklady Earth Sciences》2016,466(2):169-172
The results of studies on the distribution regularities are presented for polychlorinated biphenyls (PCBs) of different degrees of chlorination and for organochlorine pesticides (OCPs): hexachlorobenzene (HCB), hexachlorocyclohexane (HCCH), and DDT with its metabolites in the soils along the Lena River valley and in background areas of Eastern Siberia and Mongolia. A statistically reliable correlation is found between the PCB–OCP and Corg concentrations. The highest levels of HCB are registered in the soils between 50 and 60° N. The concentrations of αand γ-HCCH increase reliably, while those of pp′-DDT and pp′-DDE decrease from south to north. A trend of the decrease in concentrations from Mongolia to the Laptev Sea is revealed for tri-, tetra-, and penta-chlorine-substituted PCB congeners. However, the soils sampled northwards from 60° N show a reliable increase in the concentrations of tetra-, penta-, and hexachlorine-substituted congeners. 相似文献
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N. A. Krivolutskaya B. V. Belyatsky V. F. Smolkin V. P. Mamontov A. S. Fanygin N. M. Svirskaya 《Geochemistry International》2010,48(11):1064-1083
First isotopic-geochemical data were obtained on basite-ultrabasite rocks from the southern Kovdor area that were previously
provisionally ascribed to the drusite (coronite) complex based on the occurrence of drusite (coronite) textures. The mineral
and whole-rock Sm-Nd isochron age determined for five rock samples from the Sorkajoki and Poioiva massifs and the massif of
Elevation 403 m turned out to be close (within the error): 2485 ± 51, 2509 ± 93, and 2517 ± 75 Ma, respectively. The crystallization
age was evaluated for the two massifs (Poiojovski and Mount Krutaya Vostochnaya) by the U-Pb system of zircons. Our samples
contained both magmatic and xenogenic crustal zircons, whose age was estimated at 2700 Ma. The crystallization age of the
massifs themselves (data on the magmatic zircons) is 2410 ± 10 Ma. The undepleted character of the mantle source (ɛNd = +0.9)
and the much younger age of the massifs than that of other known manifestations of ultrabasic magmatism in the territory of
Karelia and the Kola Peninsula (including the layered pluton classic drusite massifs) suggest that the central part of the
Belomorian Mobile Belt hosts one more independent intrusive rock complex, which has never been recognized previously and which
is different from typical drusites. 相似文献
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M. I. Kuzmin E. N. Tarasova V. A. Bychinskii E. B. Karabanov A. A. Mamontov E. A. Mamontova 《Water Resources》2009,36(4):418-430
The concentrations of particulate and dissolved organic matter and mineral nutrients in the Lena River and its major tributaries are analyzed. The concentrations of these components are shown to be nonuniform and feature wide variations under the effect of matter input by major tributaries. The total fluxes of matter increase downstream the river in agreement with increasing water runoff. The effect of delta in matter accumulation is considered. The organic matter in the Lena was found to be represented mostly by soil terrigenous material. 相似文献
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Gorbunov M. E. Koval O. A. Mamontov A. E. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(1):52-60
Izvestiya, Atmospheric and Oceanic Physics - The phase-screen (split-step) method is widely used for modeling wave propagation in inhomogeneous media. The method of plane phase screens is best... 相似文献
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N. A. Krivolutskaya V. F. Smol’kin N. M. Svirskaya V. P. Mamontov A. S. Fanygin B. V. Belyatskii I. A. Roshchina 《Geochemistry International》2010,48(5):465-491
The comparative-geochemical study was first conducted for the ultrabasic-basic massifs of the central part of the Belomorian
mobile belt, which were previously ascribed to the drusite complex on the basis of the presence of coronal textures. The studied
magmatic bodies are geochemically heterogeneous and can be subdivided into three groups: (1) high-Mg rocks (MgO > 20 wt %)
with elevated Cr content, enriched trace element patterns, and deep negative Ta-Nb anomaly (Sorkajoki Massif). Intrusions
of this group are geochemically close to the layered plutons of Northern and Eastern Karelia (Kivakka, Burakovsky) and to
the intrusions of the Kola Peninsula (Monchepluton and others); (2) low-Mg intrusions (MgO < 10 wt %) with elevated contents
of Fe, Ti, and P (403-m Height Massif). The rocks composing these intrusions are characterized by subhorizontal trace element
patterns and weak Ta-Nb anomaly; (3) intrusions with intermediate MgO contents (10–20 wt %), flat, occasionally depleted REE
patterns, and lack of Ta-Nb anomaly (Mt. Grob Tundra). The identified geochemical differences do not depend on the degree
of metamorphic transformations, but were presumably caused by differences in phase and chemical composition of parental magmas,
as well as by conditions of their crystallization. It was substantiated that ultrabasic-basic massifs presently united into
the drusite complex are genetically diverse and acquired similar textural appearance due to regional metamorphism. Thus, the
presence of coronal textures is insufficient to ascribe the intrusions to the drusite complex, their mineralogical and geochemical
composition should be taken into account. 相似文献
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Disperse megaspores were first found in the Lower Visean deposits of the Kaluga region (1P/A borehole). A layered distribution of the megaspores in the studied section is shown. A large number of megaspores were established in the lower part of the section of the Bobrikovskian deposits. Higher along the section, there is a trend to a decrease in the number of megaspores until they disappear completely in the Tula deposits. Two megaspore assemblages were identified. A great variety of species was observed in the lower assemblage; the dominant megaspores are Zonalesporites brasserti and Aphanozonatisporites triglobatus. The only dominant species was recorded in the upper assemblage, Zonalesporites brasserti, with a low species diversity of the entire assemblage. The miospore and megaspore assemblages that are typical of the Lower Visean in the section of the analyzed borehole are compared. 相似文献
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Polychlorinated biphenyls and organochlorine pesticides in bottom sediments of the Irkutsk Reservoir
The concentrations of organochlorine pesticides (HCCH, DDT, and HCB) and 34 congeners of polychlorinated biphenyls were studied in bottom sediments of the Irkutsk Reservoir, the first in the Angara Chain of Reservoirs. The degree of pollution of bottom sediments was evaluated in accordance with classifications of regional and international standards. A correlation was found to exist between the distribution of some organic compounds and organic carbon concentration. 相似文献
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