The miniaturized Möessbauer spectrometer MIMOS II for the Phobos-Grunt mission     

D. S. Rodionov  G. Klingelhoefer  E. N. Evlanov  M. Blumers  B. Bernhardt  J. Gironés  J. Maul  I. Fleischer  O. F. Prilutskii  A. F. Shlyk  V. M. Linkin  C. d’Uston 《Solar System Research》2010,44(5):362-370

Möessbauer spectroscopy is a powerful tool for the mineralogical analysis of Fe-bearing materials. The miniaturized Möessbauer spectrometer MIMOS II has already been working on the surface of Mars for 6 years as part of the NASA Mars Exploration Rovers mission. The improved version of the instrument is a component of the scientific payload of the Phobos-Grunt mission. The scientific objectives of the instrument are the following: to identify the iron-bearing phases, to determine the quantitative distribution of iron among these phases, and to determine the distribution of iron among its oxidation states.  相似文献   

U-Pb (SIMS SHRIMP-II) age of volcanic rocks from the Tulukuev caldera (Streltsov Uranium-Ore Cluster,Eastern Transbaikalia)     

G. A. Shatkov  N. G. Berezhnaya  Ye. N. Lepekhina  N. V. Rodionov  I. P. Paderin  S. A. Sergeyev 《Doklady Earth Sciences》2010,432(1):587-592

The precision dating (U-Pb local by zircons, SHRIMP-II) of volcanic rocks in the unique uranium-bearing structure of Transbaikalia is performed for the first time. The basic conclusions are as follows. The volcanic activity in the Tulukuev caldera covers the period of not less than 30–35 mln years, within the period from (not later than) 162 to 128 mln years. Two stages of caldera evolution are established: the early (trachydacite-basalt) stage up to 154 mln years and the late (trachybasalt-rhyolite) stage from 142 to 128 mln years, with a 10 mln year break, which caused the deep erosion of the lower layer. Three phases of rhyolite magmatism are substantiated. The first one, 142 mln years, is the ejection of ignimbrites (microfelsitic rhyolites); the second one, 137–135 mln years, is the outflow of lavas of sanidine-morion rhyolites and subvolcanic and ring dyke intrusions. The third phase, 128 mln years, is connected with the occurrence of cesium-bearing perlites in the southwestern part of the caldera. The age of the granite-porphyries of the Krasnokamensk stock almost coincides with the precision data of the age of the uranium ores [4]. It is found that zircons from the granite-porphyries within the ore field of the Argunsk deposit have an anomalously high content of uranium. This fact can additionally testify to the time-and-spatial closeness of magmatism and processes of ore formation.  相似文献   

Composition of melt inclusions and age of zircons from plagiogneisses of the archean complex in the Kola superdeep borehole, Baltic Shield     

V. P. Chupin  V. R. Vetrin  N. V. Rodionov  D. I. Matukov  N. G. Berezhnaya  S. A. Sergeev  F. P. Mitrofanov  Yu. P. Smirnov 《Doklady Earth Sciences》2006,406(1):153-157

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Waterborne GPR mapping of stratigraphic boundaries and turbidite sediments beneath the bottom of Lake Polevskoye,Karelia, NW Russia     

Ryazantsev  P.  Rodionov  A.  Subetto  D. 《Journal of Paleolimnology》2021,66(3):261-277

Journal of Paleolimnology - We used waterborne Ground Penetrating Radar (GPR) for mapping stratigraphic boundaries, sedimentation environments, and specific features of lacustrine sediments of...  相似文献   

Molybdenum mineralization in the ores of the Tigriny tin deposit (Primorye,Russia)     

S. M. Rodionov  A. A. Schnaider  N. P. Romanovsky  V. G. Gurovich 《Geology of Ore Deposits》2007,49(4):285-296

The molybdenum mineralization at the Tigriny tin deposit is considered for the first time in the light of possible recovery of Mo as a by-product of selective mining. It is established that Mo has a positive correlation with Bi and does not show a correlation with Sn, W, or Zn. The highest Mo grade (>0.1%) in the ore stockwork is related to hornfels near the exposed granite porphyry stock and decreases downward by an order of magnitude. At the level of adit 5, the most numerous quartz-molybdenite veinlets develop at a distance of 50–100 m from the granite porphyry stock. The molybdenite-quartz, pegmatoid, and autogreisen generations of molybdenum mineralization are related to different substages of the first ore stage. All these generations predated crystallization of wolframite, cassiterite, and other ore minerals. The formation temperature for each molybdenite generation was determined by homogenization of fluid inclusions in quartz and decrepitation of samples characterizing each molybdenite-bearing assemblage. These data allowed us not only to estimate the crystallization temperature of each molybdenite generation but also to establish that the molybdenite crystallized from a pneumatolytic-hydrothermal melt-solution at the early stage of the deposit formation. The molybdenum mineralization is genetically related to the granite porphyry stock. The structure of the quartz-molybdenum stockwork was studied to determine the clusters of quartz-molybdenite veinlets and establish their orientation. Molybdenite 1 occurs in variably oriented veinlets that make up a stockwork around the apical portion of the porphyry stock. Disseminations and pockets of molybdenites 2 and 3 are hosted in pegmatoid rocks, greisen, and greisenized granite porphyry. The density of the Tigriny stockwork varies from 0 to 40–50 quartz-molybdenite veinlets per 5 m. Their orientation and spatial distribution were studied in quantitative terms. The most promising targets for selective mining of molybdenite from the Tigriny deposit are the framework of the Minor porphyry stock and the apical portion of the Main stock. The Tigriny deposit demonstrates a clear relationship between ore formation and granitic magmatism.  相似文献   

Aleksandr Stepanovich Svarichevskii (1943–2006)     

A. I. Khanchuk  S. M. Rodionov  G. L. Kirillova 《Russian Journal of Pacific Geology》2007,1(3):304-305

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Petrology of postorogenic granitoids of the northern Baltic Shield     

V. R. Vetrin  N. G. Berezhnaya  N. V. Rodionov 《Doklady Earth Sciences》2006,411(2):1476-1479

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Atmospheric teleconnection patterns and severity of winters in the Laurentian Great Lakes basin     

Sergei Rodionov  Raymond Assel 《大气与海洋》2013,51(4):601-635

Abstract

We analyzed the relationship between an index of Great Lakes winter severity (winters 1950–1998) and atmospheric circulation characteristics. Classification and Regression Tree analysis methods allowed us to develop a simple characterization of warm, normal and cold winters in terms of teleconnection indices and their combinations. Results are presented in the form of decision trees. The single most important classifier for warm winters was the Polar/Eurasian index (POL). A majority of warm winters (12 out of 15) occurred when this index was substantially positive (POL > 0.23). There were no cold winters when this condition was in place. Warm winters are associated with a positive phase of the Western Pacific pattern and El Niño events in the equatorial Pacific. The association between cold winters and La Niña events was much weaker. Thus, the effect of the El Niño/Southern Oscillation (ENSO) on severity of winters in the Great Lakes basin is not symmetric. The structure of the relationship between the index of winter severity and teleconnection indices is more complex for cold winters than for warm winters. It takes two or more indices to successfully classify cold winters. In general, warm winters are characterized by a predominantly zonal type of atmospheric circulation over the Northern Hemisphere (type W1). Within this type of circulation it is possible to distinguish two sub‐types, W2 and W3. Sub‐type W2 is characterized by a high‐pressure cell over North America, which is accompanied by enhanced cyclonic activity over the eastern North Pacific. Due to a broad southerly “anomalous” flow, surface air temperatures (SATs) are above normal almost everywhere over the continent. During the W3 sub‐type, the polar jet stream over North America, instead of forming a typical ridge‐trough pattern, is almost entirely zonal, thus effectively blocking an advection of cold Arctic air to the south. Cold winters tend to occur when the atmospheric circulation is more meridional (type C1). As with warm winters, there are two sub‐types of circulation, C2 and C3. In the case of C2, the jet stream loops southward over the western part of North America, but its northern excursion over the eastern part is suppressed. In this situation, the probability of a cold winter is higher for Lake Superior than for the lower Great Lakes. Sub‐type C3 is characterized by an amplification of the climatological ridge over the Rockies and the trough over the East Coast. The strongest negative SAT anomalies are located south of the Great Lakes basin, so that the probability of a cold winter is higher for the lower Great Lakes than for Lake Superior.  相似文献   

Morphology of the secondary cosmic microwave background anisotropies: the key to 'smouldering' reionization     

Nickolay Y. Gnedin  Sergei F. Shandarin 《Monthly notices of the Royal Astronomical Society》2002,337(4):1435-1440

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The Near-Nuclear Coma of Comet Halley in March 1986     

Szegö  Karoly  Crifo  Jean-François  Rodionov  Alexander V.  Fulle  Marco 《Earth, Moon, and Planets》2002,90(1-4):435-443

The cameras carried onboard the flyby missions to comet P/Halleyin 1986 imaged the near nuclear jet activity fromseveral spatial directions. The observed, very structured near nucleardust jets were considered at that timeas the result of dust emission from well localized active surface regions(without supporting 3-D model computations, however).Based on the first, recently developed 3-D gas dynamical model ofP/Halley's activity,we have been shown that jet features can be reproduced assuming ahomogeneous dusty icenucleus surface. The dust in the collisional near nuclear comais concentrated along the gas flow discontinuities resulting from thecomplicated surface orography, creating the visual impression ofdust jets. We present here the results of these calculations forthe near nucleus dust distributions,and we compare them with the direct observations made during thethree Halley flybys (Vega 1, Vega 2, and Giotto).  相似文献