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11.
V. A. Bobrov A. A. Bogush G. A. Leonova V. A. Krasnobaev G. N. Anoshin 《Doklady Earth Sciences》2011,439(2):1152-1156
When examining the peat deposit discovered in Vydrinaya bog, South Baikal region, the authors encountered anomalous Zn and
Cu concentrations for highmoors being up to 600–500 ppm on a dry matter basis in the Early Holocene beds (360–440 cm) formed
11 000–8500 years ago. It has been demonstrated that Zn and Cu are present inside the plant cells of peat moss in the form
of authigenic sulfide minerals of micron size. Apart from Zn and Cu, native Ag particles (5–7 um) have been encountered in
the peat of the Vydrinaya bog at a depth of 390–410 cm; these particles formed inside the organic matter of the plasma membrane
of peat moss containing Ca, Al, S, and Cu. This study suggests probable patterns of the formation of zinc sulfides, copper
sulfides, and native silver in peat moss. The results obtained indicate that biogenic mineral formation plays a significant
role in this system, which is a very important argument in the discussion on the ore genesis, in which physicochemical processes
are normally favored, while the role of living matter is quite frequently disregarded. 相似文献
12.
Izvestiya, Atmospheric and Oceanic Physics - An example of seven seismogenic regions of the world with different conditions of tectonic deformation confirms the reliability of confinedness of weak... 相似文献
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A technique of net sampling of zooplankton at night in the Kandalaksha and Dvinskii Bays and during the full tide in the Onezhskii Bay of the White Sea allowed us to obtain “clean” samples without considerable admixtures of terrigenous suspension. The absence of elements-indicators of the terrigenous suspension (Al, Ti, and Zr) in the EDX spectra allows concluding that the ash composition of the tested samples is defined by the constitutional elements comprising the organic matter and integument (chitin, shells) of planktonic organisms. A quantitative assessment of the accumulation of a large group of chemical elements (approximately 40) by zooplankton based on a complex of modern physical methods of analysis is presented. The values of the coefficient of the biological accumulation of the elements (Kb) calculated for the organic matter and the enrichment factors (EF) relative to the Clarke concentrations in the shale are in general determined by the mobility of the chemical elements in the aqueous solution, which is confirmed by the calculated chemical speciation of the elements in the inorganic subsystem of the surface waters of Onezhskii Bay. 相似文献
14.
Solotchina E. P. Kuzmin M. I. Solotchin P. A. Maltsev A. E. Leonova G. A. Danilenko I. V. 《Doklady Earth Sciences》2019,487(1):745-750
Doklady Earth Sciences - The results of this study on carbonate-containing bottom sediments of the shallow brackish Lake Itkul, West Siberia, are presented. The study methods applied included X-ray... 相似文献
15.
Doklady Earth Sciences - The complex of modern physical methods for studying authigenic carbonate crusts in the Miocene bryozoan bioherms of the Kazantip Cape (Kerch Peninsula) has made it possible... 相似文献
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Earlier data on heavy metal concentrations in bottom sediments of the Novosibirsk Reservoir are supplemented by new geochemical
characteristics of fine silt sediment in the near-dam part of the reservoir with the list of chemical elements extended to
55. After the beginning of the Ob’s runoff regulation by HPP dam, a new geochemical type of sediment started forming in the
new reservoir. This type of sediment features higher concentrations of chemical elements (including heavy metals), reaching
the values typical of Baikal silt recorded in the central hollow of the lake. 相似文献
18.
G. A. Leonova A. E. Mal’tsev V. N. Melenevskii L. V. Miroshnichenko L. M. Kondrat’eva V. A. Bobrov 《Geochemistry International》2018,56(4):344-361
Organogenic sediments (sapropels) in lakes are characterized by a reduced type of diagenesis, during which organic compounds are decomposed, the chemical composition of the pore waters is modified, and authigenic minerals (first of all, pyrite) are formed. Pyrolysis data indicate that organic matter undergoes radical transformatons already in the uppermost sapropel layers, and the composition of this organic matter is principally different from the composition of the organic matter of the its producers. The sapropels contain kerogen, whose macromolecular structure starts to develop during the very early stages of diagenesis, in the horizon of unconsolidated sediment (0–5 cm). The main role in the diagenetic transformations of organic matter in sediments is played by various physiological groups of microorganisms, first of all, heterotrophic, which amonifying, and sulfate-reducing bacteria. SO42? and Fe2+ concentrations in the pore waters of the sediments are determined to decrease (because of bacterial sulfate reduction), while concentrations of reduced Fe and S species (pyrite) in the solid phase of the sediment, conversely, increase. Comparative analysis shows that, unlike sapropels in lakes in the Baikal area, sapropels in southern West Siberia are affected by more active sulfate reduction, which can depend on both the composition of the organic matter and the SO42? concentration in the pore waters. 相似文献
19.
The present-day environmental state of some artificial (Irkutsk, Bratsk, and Novosibirsk reservoirs) and natural (lakes in Altai Territory and Yamal-Nenets Autonomous Okrug and the Tom River) water bodies in Western and Eastern Siberia was evaluated using biogeochemical indicators. The biogeochemical approach is presented as the best for establishing zones of risk and environmental disaster, since biogeochemical cycles play important role in aquatic ecosystems and unite all their blocks as a result of biogenic migration of chemical elements. Aquatic ecosystems transformed under anthropogenic impact are recognized and local sources of water pollution are identified. 相似文献
20.
It is shown that the influence of the cold Sea of Okhotsk, the duration of the ice cover, the weakened wave mode, and the
strong tidal currents are the main factors responsible for the formation of the recent bottom relief in Tugur Bay. Several
geomorphological zones are distinguished and characterized. 相似文献