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T. N. Palechek E. P. Terekhov A. V. Mozherovskii 《Stratigraphy and Geological Correlation》2008,16(6):650-663
The results of radiolarian analysis confirm the Campanian-Maastrichtian age of the Malokuril’skaya Formation in the Shikotan Island. The Campanian-Maastrichtian age of the formation is implied simultaneously by radiolarians and inoceramids. The studied Campanian and Campanian-Maastrichtian radiolarian assemblages include abundant specimens representing genus Prunobrachium, characteristic of which was bipolar distribution in cold-water to temperate basins. The new occurrence site of prunobrachids is established at the latitude of 43°N, the Far East of Russia. 相似文献
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M. Schneider B. Flemisch R. Helmig K. Terekhov H. Tchelepi 《Computational Geosciences》2018,22(2):565-586
This article presents a new positivity-preserving finite-volume scheme with a nonlinear two-point flux approximation, which uses optimization techniques for the face stencil calculation. The gradient is reconstructed using harmonic averaging points with the constraint that the sum of the coefficients included in the face stencils must be positive. We compare the proposed scheme to a nonlinear two-point scheme available in literature and a few linear schemes. Using two test cases, taken from the FVCA6 benchmarks, the accuracy of the scheme is investigated. Furthermore, it is shown that the scheme is linearity-preserving on highly complex corner-point grids. Moreover, a two-phase flow problem on the Norne formation, a geological formation in the Norwegian Sea, is simulated. It is demonstrated that the proposed scheme is consistent in contrast to the linear Two-Point Flux Approximation scheme, which is industry standard for simulating subsurface flow on corner-point grids. 相似文献
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A. Yu. Tkachenko O. V. Terekhov R. A. Sunyaev A. V. Kuznetsov C. Barat J. -P. Dezalay G. Vedrenne 《Astronomy Letters》2002,28(6):353-365
We present the final part of the catalog of cosmic gamma-ray bursts (GRBs) observed in the PHEBUS experiment on the Granat orbiting astrophysical observatory. The first three parts of the catalog were published by Terekhov et al. (1994, 1995a) and Tkachenko et al. (1998). The fourth part contains information on 32 events recorded from October 1994 until December 1996. We give burst light curves in the energy range 100 keV to 1.6 MeV, integrated energy spectra, and information on the fluence and energy flux at the luminosity peak for energies above 100 keV. Over the entire period of its operation, the PHEBUS instrument detected 206 cosmic GRBs. The mean ?V/Vmax? was 0.336±0.007. The mean hardness corresponding to the ratio of count numbers in the energy ranges 400–1000 and 100–400 keV is 0.428±0.018 for events with a duration shorter than 2 s and 0.231±0.004 for events with a duration longer than 2 s. 相似文献
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E. P. Terekhov A. V. Mozherovsky M. T. Gorovaya I. B. Tsoy N. G. Vashchenkova 《Russian Journal of Pacific Geology》2010,4(3):260-273
This paper reports and discusses the composition of the rocks of the Kotikovo Group (the Uchir, Zaslonovskaya, Turovskay,
and Ol’don formations) of the Terpeniya Peninsula (East Sakhalin). It is suggested that the Cenozoic deposits unconformably
overlay the Maastrichtian-Danian rocks with basal conglomerates at the base. Two main stages were distinguished in the Late
Cretaceous-Paleogene evolution of this area on the basis of our study. The first stage was responsible for the formation of
the Maastrichtian-Danian volcaniclastic and volcanogenic-sedimentary rocks of the Uchir Group, while the second stage produced
the Paleocene-Eocene sedimentary rocks of the Zaslonovskaya, Turovskaya, and Ol’don formations. The end of the first stage
(at the boundary of the Uchir and Zaslonovskaya formations) was marked by a change in the tectonic regime. This was expressed
in the weakening of the volcanic activity, the uplift of the territory, and the exposure of new provenances to erosion. During
the second, Early Paleogene stage, the area of the East Sakhalin Mountains, the Terpeniya Peninsula, and the submarine Terpeniya
Ridge represented a shallow-water marine sedimentary basin representing the western flank of the Cenozoic Pogranichnyi Basin.
The formation of the anticlinal East Sakhalin Mountains-Terpeniya Peninsula-submarine Terpeniya Ridge structure occurred during
the Late Cenozoic period of the East Sakhalin evolution. 相似文献
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A. Tkachenko O. Terekhov R. Sunyaev C. Barat J. -P. Dezalay G. Vedrenne 《Astrophysics and Space Science》1995,231(1-2):131-134
The PHEBUS instrument aboard the GRANAT observatory is able to record spectra of gamma-ray bursts in a broad energy range from 0.1 to 100 MeV. Over 180 bursts were observed by PHEBUS during five years of operation. They represent a very rich sample of events widely differing in durations, light curves and energy spectra. The problem of burst behaviour in the decay phase of the GRB events is discussed in this paper. We present here the results of the search for emission from GRB sources in 100 keV - 100 MeV range after the main burst has finished. Presence of extended emission was found in about 10% of the gamma-ray bursts detected by PHEBUS. 相似文献
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E. P. Terekhov I. B. Tsoy A. V. Mozherovskii N. K. Vagina 《Stratigraphy and Geological Correlation》2011,19(3):337-351
Shikotan Island of the Lesser Kuril Ridge forms, together with the Vityaz Ridge, the outer arc of the Kuril island-arc system. Marine Pliocene sediments first registered on the island contain diatoms and palynomorphs, which allow their dating. The thin Pliocene semiconsolidated sediments constitute the upper part of sections in the coastal and central areas of the island. They rest with the erosional surface and stratigraphic hiatus upon the Upper Cretaceous-Lower Paleogene (Campanian-Danian) Malokuril’sk Formation. The Pliocene sediments were deposited in relatively shallow-water environments of open sea near the shore, with a forest-free landscape and freshwater basins. The occurrence of reworked marine Oligocene and Miocene diatoms in these sedimentary rocks indicates their development in the Lesser Kuril Ridge area and contribution of their eroded material to the formation of Pliocene sequences. Wide development of Pliocene Marine sediments on Shikotan Island is evidence for ascending movements in the region during the post-Pliocene period, which is also characteristic of the Greater Kuril Ridge islands. The composition and formation conditions of the Pliocene sediments in the outer arc of the Kuril island-arc system suggest that the southwestern (Lesser Kuril Ridge) and northeastern (Vityaz Ridge) segments of this single anticlinal structure evolved under different tectonic regimes through the Pliocene. 相似文献
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J -P. Dezalay C. Barat R. Talon O. Terekhov R. Sunyaev A. Kuznetsov 《Astrophysics and Space Science》1995,231(1-2):115-118
Statistical studies of Gamma-Ray Burst (GRB) properties have recently led to the discovery of a subclass within the population of classical events (Dezalayet al. 1992, Kouveliotouet al. 1993). Bursts belonging to this subclass are characterized by short durations, typically less than 2 seconds, and harder spectra on average. Using the PHEBUS GRB data set, we analyse the distributions of peak intensity, hardness ratio, and duration of the two subclasses. We also compare the sum spectra obtained with the brightest events to determine the ratio of total energies observed for each population. 相似文献
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Olivine-bearing varieties of garnet–clinopyroxene crystalline schists of the Lapland granulite belt have been studied in detail for the first time. Two types of olivine (iron mole fractions of 27 and 38%) are distinguished. Olivine with lower Fe content occurs as inclusions in clino- and orthopyroxene and in terms of СаО and Cr contents is close to magmatic minerals. Olivine with high Fe content presumably suffered highand moderate-temperature metamorphism. The olivine-bearing rocks contain several grains of omphacite with 30–37 mol % jadeite and garnet with 44–50 mol % pyrope, which can be regarded as relict assemblages of the early stage of eclogitization of a magmatic protolith. The presence of symplectites indicates their retrograde transformation during decompression. The protoliths of the studied rocks could be olivine gabbronorites and pyroxenites. It was found that the rocks contain high-alumina minerals: corundum, spinel, and sapphirine. In addition, Al2O3 content in some amphibole grains is as high as 19 wt %. This indicates that the ascent of the deep-seated rocks was accompanied by interaction with Al-rich fluid. The positive Eu anomaly in the olivine-bearing rocks and some of their minerals is indicative of the reducing character of fluid. Activation of fluid reworking leading to the formation and transformation of the olivine-bearing rocks, transfer of alumina and its precipitation at different depths are related to the processes at the base of the Paleoproterozoic rift system of Karelides. 相似文献