Study of neotectonic activity of morphostructures in the central part of the east european craton by remote sensing methods     

V. V. Adushkin  I. A. Sanina  I. S. Vladimirova  Yu. V. Gabsatarov  E. M. Gorbunova  G. N. Ivanchenko 《Izvestiya Physics of the Solid Earth》2014,50(2):169-176

The combined approach is used for studying recent tectonic activity in the central part of the East European Craton (EEC).This approach incorporates the methods of automated lineament analysis and satellite geodesy with the conventional geological mapping analysis. The space tectonic map (space image based) is reconstructed, and morphostructures that are active at the recent and present tectonic stage are delineated by processing the Landsat image mosaic. The direction and rate of horizontal displacement of crustal blocks, which is caused by deep geodynamical processes, are determined using the GPS data. The study is preliminary since only few GPS stations within the EEC have sufficiently long time series of observations.  相似文献   

Post-seismic motions after the 2006–2007 Simushir earthquakes at different stages of the seismic cycle     

Lobkovsky  L. I.  Vladimirova  I. S.  Gabsatarov  V. V.  Garagash  I. A.  Baranov  B. V.  Steblov  G. M. 《Doklady Earth Sciences》2017,473(1):375-379

Doklady Earth Sciences - We analyzed long-term satellite geodesic observations after the Simushir earthquakes of 2006–2007. Application of a key model of the structure of the island arc...  相似文献   

Seismotectonic deformations related to the 2010 Maule earthquake at different stages of the seismic cycle from satellite geodetic observations     

Lobkovsky  L. I.  Vladimirova  I. S.  Gabsatarov  Yu. V.  Baranov  B. V.  Garagash  I. A.  Steblov  G. M. 《Doklady Earth Sciences》2017,477(2):1498-1503

Doklady Earth Sciences - The interpretation of multiannual satellite geodetic observations after the 2010 Maule earthquake is given on the basis of the keyboard concept of the subduction region...  相似文献   

Physical and chemical conditions of the formation and evolution of late pleistocene-holocene magmas of the Gorely and Mutnovsky volcanoes, southern Kamchatka   总被引：1，自引：0，他引：1  

A. A. Chashchin  Yu. A. Martynov  A. B. Perepelov  N. I. Ekimova  T. P. Vladimirova 《Russian Journal of Pacific Geology》2011,5(4):348-367

A detailed mineralogical and geochemical study of basic volcanic rocks from the modern edifices of the Gorely (Q₃⁴-Q₄⁴) and Mutnovsky (Q₃²-Q₄) volcanoes, as well as the results of numerical modeling with the COMAGMAT program, made it possible to estimate the role of fractional crystallization, the fluid regime, and geodynamic conditions in the petrogenesis of the studied basaltoids. The specific features of the evolution of magmas of the two volcanoes give grounds to suggest that beginning from the Late Pleistocene (Q₃⁴), all of the considered territory experienced a change in geodynamic regime, with an increasing role of extending strains in its evolution.  相似文献   

Modern geodynamically active zones in the Central East European Craton     

V. V. Adushkin  I. A. Sanina  I. S. Vladimirova  Yu. V. Gabsatarov  E. M. Gorbunova  G. N. Ivanchenko 《Doklady Earth Sciences》2013,452(2):1042-1045

  相似文献   

A model of radionuclide transfer by groundwater on the territory of the Russian Research Centre Kurchatov Institute     

V. I. Malkovsky  V. I. Velichkin  Yu. E. Gorlinsky  E. I. Vladimirova 《Geology of Ore Deposits》2009,51(4):275-289

The convective transfer of ¹³⁷Cs and ⁹⁰Sr by groundwater on the territory of the Russian Research Centre Kurchatov Institute (RRCKI) was modeled. Geological data on the RRCKI site and possible sources of radionuclides show that the uppermost aquifer, composed of Quaternary sediments, is the most probable region of spreading of radioactive contamination. Since the lateral migration of radionuclides is predominant, a 2D horizontal model was used for the forecasting of spreading of radioactive contaminants in the subsurface medium. Transient or long-term repositories of radioactive materials at the RRCKI site (concentrated sources) and aquifer rocks contaminated in the course of removal of radionuclides from these repositories (distributed source) are responsible for groundwater pollution. The initial ¹³⁷Cs and ⁹⁰Sr distributions used in the forecasting of radionuclide migration were determined from their contents in core samples taken from wells drilled in contaminated areas of the RRCKI site. The zone of radionuclide migration is limited by poorly permeable moraine loam from below and by the water table from above. To determine the upper and lower boundaries, these surfaces were mapped in plan view. The data of meteorological observations over a long period were used to map the intensity of precipitation in the studied territory. The density of rocks in the uppermost aquifer and partition coefficients of radionuclides between rocks and groundwater were estimated from the data of laboratory examination of the core samples. The available data on the permeability of rock samples and the results of test pumping out of some wells were involved in the consideration. The results obtained and the data on the water table allowed us to define a gauge problem for determining the distribution of the filtration coefficient in the uppermost aquifer. This problem was solved taking the intensity of precipitation into account. The properties of the uppermost aquifer and the initial radionuclide distribution therein were used as initial data for modeling ¹³⁷Cs and ⁹⁰Sr migration on the territory of the RRCKI over 50 years.  相似文献   

Geochemistry of granitization and magmatic replacement of basic volcanic rocks in the contact aureole of the Yurchik gabbronorite intrusion, Ganal Range, Kamchatka     

I. A. Tararin  Z. G. Badredinov  S. I. Dril’  N. S. Gerasimov  G. P. Sandimirova  T. A. Vladimirova 《Geochemistry International》2013,51(11):896-911

Geological and geochemical data indicate that the formation of the granulite-like rocks in the contact aureole of the Yurchik gabbronorite intrusion of the Ganal Range, Kamchatka, was caused by the contact metamorphism, metasomatism, and local melting of the initial volcanosedimentary rocks of the Vakhtalka Sequence of the Ganal Group. The temperature in the inner part of the aureole reached 700–800°C and caused the transformation of the basic volcanic rocks of the sequence into two pyroxene-plagioclase, clinopyroxene-amphibole-plagioclase, and amphibole-plagioclase hornfelses, while sedimentary rocks were converted into garnet-biotite ± cordierite hornfelses. The hornfelsed basic volcanic rocks were locally subjected to metasomatic alteration and magmatic replacement with formation of biotite-orthopyroxene-plagioclase metasomatic bodies containing biotite-orthopyroxene-plagioclase ± garnet veinlets and aggregates. During these processes, sedimentary interlayers were converted into garnet enderbites at 700–800°C and 3.2–4.8 kbar. The comparison of the chemical composition of basic volcanic rocks of the Vakhtalka Sequence and their transformation products indicates that the metasomatic alteration and magmatic replacement correspond to siliceous-alkaline metasomatism (granitization) and cause subsequent and uneven influx of SiO₂, Al₂O₃, Na₂O, K₂O, Rb, Ba, Zr, Nb, and Cl and removal of Fe, Mg, Mn, Ca, Cr, Co, Ti, Y, and S. REE data on basic metavolcanic rocks, hornfelses, and metasomatites suggest that the processes of hornfelsation, metasomatism, and magmatic replacement of the initial volcanic rocks were accompanied by significant increase in LREE and slight decrease in HREE. The Sr and Nd isotope study of the rocks in the aureole showed that the initial basic volcanic rocks of the Vakhtalka Sequence are isotopically close to both mature island arc tholeiites and mid-ocean ridge basalts. The metasomatic alteration and magmatic replacement of volcanic rocks in the aureole lead to the decrease of ¹⁴³Nd/¹⁴⁴Nd and increase of ⁸⁷Sr/⁸⁶Sr approximately parallel to mantle array. Pb isotopic ratios in the studied rocks become more radiogenic from initial metavolcanic rocks to metasomatites. It is suggested that the processes of metamorphism, metasomatism, and magmatic replacement were caused by highly mineralized mantle fluids, which percolated along magmatic channels serving as pathways for gabbroid magma.  相似文献   

Study of the Features of Seismogenic Activation of the Chilean Subduction Zone at the Beginning of the 21st Century     

Vladimirova  I. S. 《Doklady Earth Sciences》2022,507(2):1112-1117

Doklady Earth Sciences - The analysis of seismotectonic deformations associated with the seismogenic activation of the Chilean subduction zone at the beginning of the 21st century is reported. The...  相似文献   

Isotopic signatures of strontium,neodymium, and lead in metamorphic rocks of the Khavyven highland in eastern Kamchatka     

I. A. Tararin  S. I. Dril  G. P. Sandimirova  Z. G. Badredinov  S. A. Tatarnikov  T. A. Vladimirova 《Doklady Earth Sciences》2010,431(1):356-360

Metamorphic units of the Khavyven Highland that crop out in the northern portion of the Khavyven Uplift of the basement structures of the Central Kamchatka Trough are formed by rocks of the Khavyven Formation, which are metamorphosed in the green-schist facies. The formation comprises two strata: the lower part that consists of amphibole-micaceous ± garnet, epidote-micaceous ± garnet crystalline schists, and micaceous ± garnet quartzite schists has a total thickness of some 500 m, and the upper part, which is formed by epidote-amphibole and phengite-amphibole green schists and overlying epidote-amphibole-micaceous quartzites, with a visible thickness of some 750 m. The isotopic ratios of Sr, Nd, and Pb were determined in the examined rocks of the Khavyven Formation for the first time. The high ⁸⁷Sr/⁸⁶Sr and low ¹⁴³Nd/¹⁴⁴Nd ratios and the high K/La, Ba/Th, Th/Ta, and La/Nb ratios in combination with a deep Ta-Nb minimum indicate that the original volcanites of the crystalline schists of the lower rock mass had a subduction nature. The green schist of the upper rock mass, whose composition corresponds to that of spilitic basalts, have elevated ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd ratios, thus combining indications of depleted melts of the N-MORB and E-MORB types and those of subduction melts, which explains the deep Ta-Nb minimum and the low (La/Yb) _N ratios. The isotopic signatures of lead in rocks of the lower and the upper strata are similar. The composition points of the crystalline schists and the green schists are located near the trend of isotopic evolution of lead in the depleted mantle, which indicates that the rocks are closely related to this mantle source.  相似文献   

Viscoelastic deformations after the 2006–2007 Simushir earthquakes     

I. S. Vladimirova  G. M. Steblov  D. I. Frolov 《Izvestiya Physics of the Solid Earth》2011,47(11):1020-1025

Continuous measurements at the Kuril GPS network since 2006 have revealed anomalous coseismic and postseismic displacements of the Earth’s crust, which accompanied the great 2006–2007 earthquake doublet in the central Kuriles and were observed during 2.5 years after the events. Prior to the earthquakes, all observation sites of the Kuril network were moving towards the continent due to the subduction deformation of the continental margin. After the events, the direction of displacement had changed to the opposite direction at the stations located on the Matua, Ketoy, and Kharimkotan Islands, which were the nearest to the seismic events, and experienced a significant turn on the Urup Island nearby. Modeling of postseismic viscoelastic relaxation of strains in the asthenosphere suggested an acceptable explanation for the long-term anomalous offsets revealed. By solving the corresponding inverse problems, we estimated the viscosity of the upper mantle and constrained the slip distribution of the 2006 Simushir earthquake.  相似文献