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31.
M. M. Ivanov N. N. Ivanova V. N. Golosov E. N. Shamshurina 《Geography and Natural Resources》2016,37(4):355-361
We examine the use of two alternative techniques for assessing the redistribution volumes of sorbed 137Cs within the upper components of the fluvial network, based on the concept of catchment as a lithodynamical system. In terms of one of them, we made a substantive analysis of changes in reserves on accumulative positions where the 137Cs distribution curves showed a significant increase in radionuclide content levels. We carried out a typization o the accumulation surfaces in order to extrapolate data, obtained for a group of soil profiles, to the territory of the entire catchment and to make a direct assessment of the increases in accumulation. An alternative technique was used to assess the volumes of accumulated sediment loads on accumulative positions by analyzing the 137Cs distribution curves, and to correlate with denudation zones in the drainage area under consideration. Values of the wash-out rates for the period 1986–2012 have been obtained, which are necessary for the formation of the accumulative layer observed. We calculated the volume of 137Cs swept away during 26 years after the Chernobyl accident, based on information regarding the volumes of initial reserves in the denudation zones and a correlation between the erosion rate and a specific reduction in reserves. It is established that the technique on the basis of analyzing the wash-out zones featuring high economical efficiency can be used in assessing 137Cs migration for larger territories with relatively low labor-consuming effort. 相似文献
32.
The primary scientific goal of studying salt lakes is to better understand the formation of small continental-type hydrogeochemical systems. Many scientists have attributed the metamorphism of the chemical composition of salt lakes to the evaporative concentration of water. However, the formation of soda water is inconsistent with this hypothesis. Thus, analyzing intrabasinal biochemical processes and water—rocks interactions during the evaporative concentration of water allows us to understand the major mechanisms of the formation and evolution of water compositions. Therefore, the aim of this paper is to identify the key processes involved in the formation of the chemical composition of the water in Lake Doroninskoye. An analysis of the distribution of major components shows that Na+, HCO3 ?, CO3 2?, and Cl? are dominant in this water. High concentrations of these elements are the result of evaporative water concentration. Calcium, magnesium, and potassium are not accumulated because the water is saturated in minerals containing these elements. The main barrier to the growth of the sulfate content of water is sulfate reduction. This process also contributes to the additional reproduction of carbon dioxide, which reacts with the products of the hydrolysis of aluminosilicates OH? to form HCO3 ? and CO3 2?, thus further contributing to the natural processes of soda formation. 相似文献
33.
Corundum-containing and corundum-free plagioclasites localized in chromite-bearing ultramafites of the Rai-Iz Massif were explored for the composition and age. The composition of rock-forming minerals was studied, and the geochemical characteristics of the rocks were ascertained. The isotope age of plagioclasites determined by zircons using the U–Pb mode with a SHRIMP II device was equal to 398 ± 3 Ma. The age found conformed to the boundary on most of the Rai-Iz Massif took place against the background of a starting powerful collision, which caused the formation of the chromium mineralization of a high-chromic type, as well as the separation of a series of essentially plagioclase rocks of ruby mineralization at the discharge zones of the vein series. 相似文献
34.
35.
A. V. Maslov Yu. V. Erokhin A. Gerdes Yu. L. Ronkin K. S. Ivanov 《Doklady Earth Sciences》2018,482(2):1275-1277
Detrital zircons (DZs) from arkose sandstones of the Upper Riphean Zilmerdak Formation (Southern Urals) yielded ages in the range of 3039–964 Ma. Grains with Late Karelian and Early and Middle Riphean ages compose 35, 34, and 26% of the total number of the analyzed zircons, respectively. This is similar to the age spectra of the Vendian sandstones (Asha Group), but it differs significantly from the age distribution typical of the Riphean stratotype sandstones. 相似文献
36.
Berzin S. V. Koroteev V. A. Ivanov K. S. Kleimenov D. A. Kiseleva D. V. Cherednichenko N. V. 《Doklady Earth Sciences》2018,479(1):390-392
A fragment of the Sverdlovsk Meteorite, which was found in 1985 in the Central Urals, is studied by modern analytical methods. It belongs to H chondrites of petrologic type 4–5; shock stage of meteorite is S1-2, terrestrial weathering is W1. The composition of minerals of the meteorite is studied. It is found for the first time that the metal and sulfides are concentrated in fine veinlets of the recrystallized matrix of the chondrite and are accompanied by segregations of metal and troilite inside these veinlets. The distribution of trace elements of the metal phase of the meteorite is studied.
相似文献37.
Timokhov L. A. Ivanov V. V. Kassens H. Lebedev N. V. Frolov I. Ye. Hölemann J. 《Doklady Earth Sciences》2018,480(1):685-688
Doklady Earth Sciences - According to historical oceanographic data, anomalies in the dynamic topography during the winter period were calculated and two climatic stages of dynamic condition of the... 相似文献
38.
N.G. Granin I.B. Mizandrontsev V.V. Kozlov E.A. Tsvetova R.Yu. Gnatovskii V.V. Blinov I.A. Aslamov K.M. Kucher V.G. Ivanov A.A. Zhdanov 《Russian Geology and Geophysics》2018,59(11):1514-1525
Hydrophysical studies and mathematical modeling of ring structures during ice cover on Lake Baikal have shown that their existence at the stage of ice cover degradation is due to anticyclonic currents. Such currents can be generated as a result of local upwelling, which we associate with the rise of methane hydrates from the top layer of bottom sediments and their dissociation. Analysis of satellite images shows that the radii of ice rings range from 1300 to 2400 m, which is close to the baroclinic Rossby radius. The measured ice thicknesses in the area of the rings are in agreement with model calculations. Deep water renewal in Lake Baikal can also be associated with the rise of hydrates. 相似文献
39.
R. R. Gabdullin N. V. Badulina E. A. Bakai E. V. Rubtsova A. Yu. Yurchenko E. V. Karpova A. V. Ivanov M. A. Varzanova A. V. Sergienko T. A. Konovalova M. V. Parakhina 《Moscow University Geology Bulletin》2018,73(4):346-360
The composition and origin of the Callovian–Oxfordian deposits of the Sudak Bay were characterized on the basis of the generalization and analysis of our own results, as well as published and unpublished data. The botanical future was first implemented for the geological mapping of the Oxfordian deposits. 相似文献
40.
Doklady Earth Sciences - Gold placers of two streams that drain Permian dislocated terrigenous deposits overlying Cambrian metagabbroids and metadiorites in southern Sikhote-Alin have been studied.... 相似文献