Rare-earth and rare elements in zircons of different ages from corundum-bearing rocks of Khitoostrov (Northern Karelia)     

Krylov  D. P.  Glebovitskii  V. A.  Skublov  S. G.  Tolmacheva  E. V. 《Doklady Earth Sciences》2012,443(1):406-411

Doklady Earth Sciences -  相似文献   

Peculiarities of distribution and transformation of water in the Keret’ River tidal estuary     

S. S. Krylov  N. Yu. Bobrov  G. V. Pryakhina  S. S. Bricheva  V. V. Ionov 《Russian Meteorology and Hydrology》2014,39(10):677-684

Presented are the results of the study of the processes of interaction between the river and sea water in the estuary of the Keret’ River flowing into the White Sea. The studies were carried out using the georadar method which enables one to register the boundary between fresh and salt water with the high spatial and temporal resolution. The use of this method helped to determine the boundaries of the area of distribution of fresh water in the estuary during different phases of the tidal cycle and to reveal the typical fluctuations of the boundary between fresh and salt water manifested at different values of river runoff and weather conditions.  相似文献   

Riphean basins of the central and western Siberian Platform   总被引：1，自引：0，他引：1  

Sergey V. FrolovGrigorii G. Akhmanov  Elena V. KozlovaOleg V. Krylov  Ksenia A. SitarYuriy I. Galushkin 《Marine and Petroleum Geology》2011,28(4):906-920

The Siberian Platform is unique by its volume of Meso-Neoproterozoic sedimentary deposits. For about one billion years (∼1650-650 Ma) several sedimentary basins were developed here, resulting in the formation of several kilometers thickness of sedimentary cover. The Riphean (Mesoproterozoic-Lower Neoproterozoic) rocks are exposed mainly along platform peripheries. The most complete sections are represented by several megacycles. Each megacycle contains terrigenous series at the base and carbonate formations in the upper part. Several isolated and anisochronous basins were created during the Riphean on the territory of East Siberia. Some of them were intracratonic, others were developed on passive margins. Neoproterozoic orogeny along the platform boundaries resulted in re-organization of the Siberian basins, with extensive faulting, uplifting and erosion of the territories.In eastern Siberia, Riphean series contain large hydrocarbon accumulations. The reservoirs were formed mainly due to fracturing and leaching of carbonate strata (e.g. vugular carbonates of the pre-Vendian weathering crust). The Upper Proterozoic deposits are overlain by thick clayey-carbonate and saliferous-carbonate series of the Upper Vendian and Cambrian, isolating them from the upper sedimentary cover. The Riphean basins contained thick, organic rich, clayey and clayey carbonate. In some of them a hydrocarbon generation maximum took place at the end of the Riphean. The pre-Vendian erosion has removed a significant volume of Riphean sediments. During this time a majority of already formed hydrocarbon accumulations have been lost or degraded. Remaining Riphean series have generated hydrocarbons during the Paleozoic.Despite its complex history, the Riphean is still considered highly prospective, with source rocks developing at multiple levels and reservoirs occurring in both carbonate and clastic rocks. Discoveries of new oil-and-gas fields in East Siberia are likely, but will depend on integration of detailed seismic data and a large volume of core data for the correct prognosis of Riphean reservoir distribution.  相似文献   

Xes-Xen thermochronology of the Rayner metamorphic complex,Enderby Land (East Antarctica,Molodezhnaya Station Area)     

D. P. Krylov  Yu. A. Shukolyukov 《Petrology》2014,22(5):438-449

The Xe_s-Xe_n dating of zircons from rocks of the Rayner Complex of the Enderby Land at the Molodezhnaya Station area (coast of the Alasheyev Bight) yielded age estimates of 550 ± 50 and 1040 ± 30 Ma. The metamorphic rocks of the Rayner Complex record two main events: first, the crystallization of the magmatic protoliths of charnockitic and enderbitic gneisses and, second, superimposed structural and metamorphic alterations under conditions transitional from the amphibolite to granulite facies (metamorphism manifested regionally in the rocks of the Rayner Complex). The most reliable Xe_s-Xe_n age estimates for magmatic zircons from the charnockitic and enderbitic gneisses correspond to the Grenville stage of the development of the Rayner Complex (～1.0 Ga). The Xe isotopic systematics of metamorphic zircons reflect a pan-African stage in the evolution of the Rayner Complex (600–550 Ma). Pan-African events are reflected in the U-Xe isotope system in two cases: if metamorphic zircons crystallized at the same time (which probably resulted in the formation of a plateau in the Xe_s-Xe_n age spectrum) and if the initial isotopic systems were disturbed (which resulted in a decrease in apparent age toward low-temperature gas fractions). It is important that secondary alterations and a decrease in apparent ages to 600–550 Ma affected only those components (i.e., caused xenon release only from those traps) that were unstable under the maximum metamorphic temperatures and yielded T _cl values lower than 750°C (conditions transitional from the amphibolite to granulite facies). At a higher xenon retention, “primary” isotopic systems are preserved. Consequently, the age of metamorphism transitional between the amphibolite and granulite facies can be estimated at 600–550 Ma on the basis of Xe_s-Xe_n dating. In general, the results of our study indicate that the age of regional metamorphism of the Rayner complex at the Molodezhnaya area is approximately 600–550 Ma rather than ～1.0 Ga, as was previously supposed.  相似文献   

Seismic hazard assessment for oil-and-gas-bearing shelf zones: A case study of the North Caspian region     

A. A. Krylov  A. I. Ivashchenko  S. A. Kovachev 《Oceanology》2015,55(6):910-915

  相似文献   

Unusually high thermal stability of the Uranium-Xenon isotopic system in nonmetamict zircons     

Shukolyukov  Yu. A.  Fugzan  M. M.  Paderin  I. P.  Sergeev  S. A.  Krylov  D. P. 《Doklady Earth Sciences》2009,425(1):287-290

Doklady Earth Sciences -  相似文献   

Factors of <Superscript>18</Superscript>O/<Superscript>16</Superscript>O fractionation in corundum estimated from the calculation of isotopic shifts on vibration frequencies     

D. P. Krylov  V. A. Glebovitskii  E. Yu. Akimova 《Geochemistry International》2017,55(6):589-594

The β-factors of corundum were estimated on the basis of DFT calculations of vibrational frequency changes due to ¹⁶O–¹⁸O isotope substitution in a harmonic approximation using an all-electron Gaussian-type basis set and the B3LYP hybrid functional (the CRYSTAL program). Calculations were performed accounting for eight phonon wave vectors within the first Brillouin zone. The results are approximated by the relation 1000ln β _crn = 9.19874x–0.12326x ² + 0.00213x ³ (x = 10⁶/T(K)², 400 < T(K) < 1300), which can be used in isotope geochemical studies in combination with the known temperature effects on the β-factors of other phases.  相似文献   

Late Vendian-Early Cambrian formations of the north-west Siberian Craton     

E. E. Karnyushina  N. I. Korobova  S. V. Frolov  G. G. Akhmanov  O. V. Krylov  N. P. Fadeeva  E. V. Zhukova  E. R. Lukina 《Moscow University Geology Bulletin》2010,65(6):367-379

The composition and structure of principal key-sections for the Tira (Late Vendian) and Danilovo (Late Vendian-Early Cambrian) Horizons were characterized on the basis of deep-drilling data and studies of natural outcrops along the peripheries of the Kureika syneclise. The typical sedimentary formations/associations were recognized, their vertical and lateral successions were distinguished, and their deposition environments were interpreted. A distribution pattern scheme of thicknesses and depositional environments of Upper Vendian-Lower Cambrian deposits was compiled at the 1: 1000000 scale. The reservoir characteristics of the formations are discussed and forecasted for poorly studied areas of the northwestern Siberian platform.  相似文献   

Structured serpentinite melanges of the Koryak-Kamchatka fold system     

S. D. Sokolov  K. A. Krylov 《Geotectonics》2010,44(1):45-59

The Kuyul, Taigonos, and Upper Khatyrka structured serpentinite melanges at the Pacific continental margin of Northeast Asia considered in this paper are diverse in tectonic setting, age, and geological history. They are characterized by an ordered internal structure expressed in regular arrangement of rock blocks different in composition. These blocks make up mappable tectonic sheets deformed into complex, nappe-related folds. Difference in the block composition of particular sheets is often combined with different composition of serpentinite matrix. The structured melanges of Cape Povorotny (Taigonos Peninsula) and the Kuyul Terrane were formed during accretion of oceanic complexes to a suprasubduction zone and their subsequent juxtaposition. The Upper Khatyrka melange comprises oceanic, island-arc, and marginal-sea complexes. The study of structured melanges makes it possible to ascertain the history of continental accretion and transformation of the oceanic crust. The combination of ordering and chaotic structure allows us to consider structured melanges as manifestations of nonlinear geodynamics.  相似文献   

Transformation of the mineral composition of ferromanganese crusts under the influence of hydrogen sulfide     

G. N. Baturin  V. T. Dubinchuk  I. O. Krylov 《Lithology and Mineral Resources》2010,45(5):401-409

Experiments devoted to interaction between the material of ferromanganese crusts (FMC) of Pacific seamounts and hydrogen sulfide at temperatures ranging from 100 to 600°C unraveled the formation of pyrite microcrystals at 100°C. Upon heating, the pyrite acquires more perfect crystalline form at 200°C and breaks down at 600°C. The formation and breakdown of magnetite take place according to the same similar scenario. At 200°C, one can see the formation of lumpy aggregates of the slightly crystallized alabandine transformed at 600°C into lamellar crystals, which accumulate the whole Mn and part of Fe hosted in rock. At maximal temperature, platinum and gold are crystallized selectively as lamellar particles and native sulfur is accumulated. The composition of these newly formed minerals is incomparable with the mineralogy of natural FMCs. This is inconsistent with the assumption about the possible influence of hypothetic hydrosulfuric emanations on the formation of minerals mentioned above. However, experimental results demonstrate an extremely high sorption capacity of FMCs relative to hydrogen sulfide, suggesting great prospects of the practical application of FMCs for the industrial and ecological purposes.  相似文献