Structural variations along the Kuril-Kamchatka trench and a possible relation to seismicity     

S. M. Zverev  M. E. Polyanskii 《Journal of Volcanology and Seismology》2008,2(1):1-15

This paper considers the results from seismic investigations of the Kuril-Kamchatka trench (KKT) using continuous seismic profiling (CSP), the common-depth point (CDP), and deep seismic sounding (DSS). The outcome is an approximate 2D seismic model that reflects the overall structure of the landward trench slope for most of the KKT, with the greatest departure of the data from the model being for the middle Kuril Islands area. A deep-seated fault has been identified in the upper part of the slope 60–80 km from the trench axis, with the fault being traceable throughout the depth interval between the seafloor and the bottom of the crust. In the portion between the fault and the trench axis the seismic velocities are lower, the gradient higher, and the crust thins rapidly seaward. The sediment thickness on the landward slope varies along the trench, reaching the maximum off the southern Kuril Islands. The structural variations along the KKT show a broad correlation with the behavior of geophysical fields and seismicity, which seems to be an expression of global tectonic processes.  相似文献   

Upper Crustal Velocity Model for the Southeastern Boundary of the Siberian Platform     

Emanov  A. F.  Polyanskii  P. O.  Sal’nikov  A. S. 《Izvestiya Physics of the Solid Earth》2021,57(3):409-424

Izvestiya, Physics of the Solid Earth - Abstract—Based on the common-mid-point (CMP) seismic data on the 3-DV reference profile, using dynamic conversion of refracted waves into time...  相似文献   

High-pressure rocks in the serpentinite melange of the Chara zone,Eastern Kazakhstan: Geochemistry,petrology, and age     

N. I. Volkova  E. N. Tarasova  N. V. Polyanskii  A. G. Vladimirov  V. D. Khomyakov 《Geochemistry International》2008,46(4):386-401

The nature of the protolith of high-pressure rocks occurring as exotic blocks in serpentinite melange in the Chara ophiolite belt, Eastern Kazakhstan, is identified based on petrological and geochemical evidence. The distribution of incompatible HFSE in these rocks suggests that their protoliths were similar to E- and N-MORB tholeiites and, more rarely, to OIB alkaline basalts. This testifies to the activity of plume magmatism in the Early Paleozoic evolution of the Paleoasian Ocean. The Ar-Ar ages of phengite and Na-amphibole from the rocks date the subduction/exhumation of high-pressure rocks in the Chara ophiolite belt at the Late Ordovician (450 ± 5 Ma).  相似文献   

Stages of formation of the Vilyui sedimentary basin: Possible mechanisms on the basis of backstripping analysis and numerical modeling     

O. P. Polyanskii  A. V. Prokop’ev  Yu. P. Stefanov 《Doklady Earth Sciences》2012,443(2):475-480

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Estimation of the emplacement depth of a magmatic intrusive body based on the data for distribution of isogrades in the surrounding metamorphic zoning (Model approximation)     

Reverdatto  V. V.  Babichev  A. V.  Korobeinikov  S. N.  Polyanskii  O. N. 《Doklady Earth Sciences》2010,430(2):244-247

A method of model calculations for the approximate estimation of the emplacement depth of magmatic intrusive body based on data for the distribution of isotherms in the near-intrusive area is proposed. Isotherms are maximums of respective temperatures reached when exocontact rocks are heated at a different time; some of them represent isogrades. The calculations require knowing the form of the intrusive body, the magma composition and initial temperature, the regional geothermal gradient in the Earth’s crust during the magma intrusion, the thermal and physical properties of rocks and melt, and the distribution of isogrades/isotherms in the enclosing rocks. The probable depth of emplacement of the Kharlovo gabbro massif in the northwestern foothill belt of Altai is estimated as an example. It was determined to be 7–8 km. The estimates of depth that are obtained in such a way cannot be absolutely accurate, since they are a result of calculations in a simplified model statement.

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U-Pb isotopic age,composition, and sources of the plagiogranites of the Kalba range,Eastern Kazakhstan     

M. L. Kuibida  N. N. Kruk  A. G. Vladimirov  N. V. Polyanskii  I. V. Nikolaeva 《Doklady Earth Sciences》2009,424(1):72-76

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