The Nature of Platinoid Minerals from Gold Placers of Southern Sikhote-Alin (Primorye)     

Ivanov  V. V.  Khanchuk  A. I.  Kolesova  L. G. 《Doklady Earth Sciences》2021,498(2):482-486

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   

Nature And Age of Granites in the Central Part of the Western Siberian Platform (Case Study of the Krivolutskii Batholith)     

Erokhin  Yu. V.  Ivanov  K. S.  Koroteev  V. A.  Shaldybin  M. V.  Khiller  V. V. 《Doklady Earth Sciences》2021,496(1):1-6

Doklady Earth Sciences - The study of granites in the basement of the Western Siberian platform is highly relevant since they are associated with hydrocarbon deposits, which are located not only...  相似文献   

Ionic Composition of the Earth’s Exosphere during a Reversal of the Solar Magnetic Field     

Ivanov  M. S.  Lapshin  V. B. 《Doklady Earth Sciences》2021,497(2):310-313

Doklady Earth Sciences - This paper analyzes measurement data on the ionic composition of the upper atmosphere at altitudes of 810–830 km in the period from 2009 to 2018; the measurements...  相似文献   

Observations of Tilt Deformations in Moscow during the November 12, 2017, Earthquake at the Iran–Iraq Boundary     

Aleshin  I. M.  Ivanov  S. D.  Perederin  F. V.  Steblov  G. M.  Kholodkov  K. I.  Shirokov  I. A. 《Doklady Earth Sciences》2021,496(2):160-163

Doklady Earth Sciences - A residual tilt after a teleseismic earthquake is described in this work. The results of static and dynamic modeling of this event fit the measured values. The conditions...  相似文献   

Authigenic carbonates from the eastern Black Sea as an archive for shallow gas hydrate dynamics – Results from the combination of CT imaging with mineralogical and stable isotope analyses     

A. Bahr  T. Pape  F. Abegg  G. Bohrmann  T. van Weering  M.K. Ivanov 《Marine and Petroleum Geology》2010

Authigenic carbonates associated with cold seeps provide valuable archives of changes in the long-term seepage activity. To investigate the role of shallow-buried hydrates on the seepage strength and fluid composition we analysed methane-derived carbonate precipitates from a high-flux hydrocarbon seepage area (“Batumi seep area”) located on the south-eastern Black Sea slope in ca. 850 m. In a novel approach, we combined computerized X-ray tomography (CT) with mineralogical and isotope geochemical methods to get additional insights into the three-dimensional internal structure of the carbonate build-ups.  相似文献   

Northern ocean inventories of organochlorine and heavy metal contamination     

Crane K  Galasso J  Brown C  Cherkashov G  Ivanov G  Petrova V  Vanstayan B 《Marine pollution bulletin》2001,43(1-6):28-60

  相似文献   

Concentrically zonal textures in a sample of the Kaidun meteorite     

A. V. Ivanov  M. A. Ivanova  N. N. Kononkova 《Geochemistry International》2007,45(10):957-970

The paper reports the results of the textural and mineralogical studying of clast Kaidun #d6A. The principal minerals of the clast are phyllosilicates, carbonates, and sulfides, but the clast contains no anhydrous silicates. The clast is characterized by extremely high concentration of inclusions, which broadly vary in size, composition, and texture, from completely remelted to practically unchanged when brought to the parent body. The latter group includes two inclusions having a concentrically zonal texture, which have never before been found in meteorites. One of the inclusions consists of serpentine replaced by talc in the margins. The inclusion was formed in relation to silification under the effect of silicon-bearing aqueous fluid at a temperature of more than 300°C. The other inclusion consists of alternating Ca carbonate and phyllosilicate zones. The texture and composition of the inclusion suggest that its genesis was related to the metasomatic alteration of carbonates under the effect of silicon- and alumina-bearing aqueous fluids at temperatures of about 400–500°C. These processes are typical of large differentiated planets, and there are no reasons to expect them in the parent bodies of carbonaceous chondrites, such as Kaidun. Our results obtained on clast #d6A are in good agreement with the hypothesis that the parent body of the Kaidun meteorite was Phobos [1]. Correspondingly, inclusions #d6Aa and #d6Ab likely originated from Mars, as previously examined alkali-rich clasts did. The clast described in this publication seems to originate from the surface regolith of Phobos, which was compacted in the process of the aqueous alteration of the material and subsequently buried at a greater depth.  相似文献   

Age and composition of ophiloites from the basement of the West Siberian petroliferous megabasin     

K. S. Ivanov  Yu. N. Fedorov  E. O. Amon  Yu. V. Erokhin  G. N. Borozdina 《Doklady Earth Sciences》2007,413(3):415-419

  相似文献   

Biogeochemical processes in the Chukchi Sea     

A. Yu. Lein  A. S. Savvichev  I. I. Rusanov  G. A. Pavlova  N. A. Belyaev  K. Craine  N. V. Pimenov  M. V. Ivanov 《Lithology and Mineral Resources》2007,42(3):221-239

Study of biogeochemical processes in water and sediments of the Chukchi Sea in August 2004 revealed atypical maximums of the concentration of biogenic elements (N, P, and Si) and the rate of microbial sulfate reduction in the surface layer (0–3 cm) of marine sediments. The C: N: P ratio in the organic matter (OM) of this layer does not fit the Redfield-Richards stoichiometric model. Specific features of biogeochemical processes in sea are likely related to the complex dynamics of water, high primary productivity (110–1400 mg C/(m² day)), low depth of basin (<50 m in 60% of the water area), reduced food chain due to low population of zooplankton, high density of zoobenthos (up to 4230 g m^?2), and high activity of microbial processes. Drastic decrease in the concentration of biogenic elements, iodine, total alkalinity (Alk), and population of microorganisms beneath the 0–3 cm layer testify to a large-scale OM decay at the water-seafloor barrier. Our original experimental data support the high annual rate of OM mineralization at the bottom of the Chukchi Sea.  相似文献   

Sm–Nd and Sr isotope systematics of scheelite from the giant Au(–W) deposit Muruntau (Uzbekistan): implications for the age and sources of Au mineralization   总被引：6，自引：0，他引：6  

U. Kempe  B. Belyatsky  R. Krymsky  A. Kremenetsky  P. Ivanov 《Mineralium Deposita》2001,36(5):379-392

The application of the Sm-Nd isotope system of scheelite to dating of low-sulfide, quartz-vein hosted Au mineralization is still under discussion. In the present work, new Sm-Nd and Rb-Sr data for scheelite from the giant Muruntau/Myutenbai Au deposit (Kyzylkum, Western Uzbekistan) are discussed. Based on the geological relationship, mineralogical properties, and trace element characteristics, two types of scheelite can be distinguished within the deposit. The first one is represented by early bluish luminescent and weakly coloured scheelite (generation 1) found within strongly deformed flat quartz veins. The apparent isochron defined by this scheelite (351ᆪ Ma) is interpreted as a mixing line. Typically brownish to orange and yellowish luminescent scheelite from steeply dipping veins (generation 2) defines a Sm-Nd isochron age of 279ᆦ Ma ()_Nd=-9.5ǂ.3; MSWD: 1.5). No evidence for mixing or disturbance by late alteration were found for these scheelites. This Sm-Nd isochron age agrees with the Rb-Sr and K-Ar age range for wall rock alteration in this deposit reported previously. The age of 280 Ma is interpreted to date the high-grade ore formation in the Muruntau deposit. There are currently no reliable age data available on the magmatic events in the Muruntau region. Probably, there is some overlap in time of the Hercynian gold deposition with the intrusion of lamprophyric dykes. The Nd and Sr isotopic signatures of scheelite define the wall rocks (mainly metasiltstones and metasandstones) as the most probable sources for these elements in scheelite.  相似文献