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MORPHOTECTONICS OF THE BASEMENT SURFACE OF THE WEST SIBERIAN BASIN WITHIN NADYM-TAZ INTERFLUVE

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Geotectonica et Metallogenia 2003年第1期27卷 11-23页

作者： DEYEV E.V. ZINOVIEV S.V. Institute of Geology SB RAS 630090 Koptyug Ave. 3 Novosibirsk RussiaInstitute of Geology SB RAS 630090 Koptyug Ave. 3 Novosibirsk Russia

The map of reflecting horizon A, plotted on the basis of regional geophysical materials, yieldsinformation about the bottom topography of sedimentary cover of the West-Siberian Basin within Nadym-Taz interfluve. Through morphotectonic analysis about this surface, the authors are able tounderstand the distribution characteristics of the main topographic irregularities, with the blockstructure of the lower cover floors and underlying complexes as the *** largest irregularities are caused by the presence of three regional altitude steps, which show a regional tendency of basement being submerged in the north-north-east direction. Within these irregularities, the authors have.distinguished some regions, which can be divided, based on the characteristics of morphostructural distribution, into two groups, i.e., areal (Nadym, Tol'ka, Urengoy)and belt (Tarko-Sale, Russko-Chasel'ka and Messoyakha). The first ones represent quasihomogeneous blocks, whose surfaces are complicated by irregular low-amplitude elevations and troughs and low-gradient zones with gradient values being up to 0.03, or they submerge stepwise, with the leveled areas being separated by zones with high gradients (0.07-0.15). The morphostructure of the other group of regions is characterized by the en-echelon distribution of contrastingly positive and negative elements with high values of slope gradients (higher than 0.1-0.2).

关键词： morphotectonics basement Siberia interfluve

The evolution of refertilized lithospheric mantle beneath the northeastern Siberian craton:Links between mantle metasomatism,thermal state and diamond potential

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Geoscience Frontiers 2022年第6期13卷 153-169页

作者： Sergei Skuzovatov Vladislav S.Shatsky Alexey L.Ragozin Alexander P.Smelov Vinogradov Institute of Geochemistry Russian Academy of SciencesSiberian Branch1AFavorskogo Str.Irkutsk 664033Russia Sobolev Institute of Geology and Mineralogy Russian Academy of SciencesSiberian Branch3Koptyug Ave.Novosibirsk 630090Russia Geology&Geophysics Department Novosibirsk State University2 Pirogova Str.Novosibirsk 630090Russia Diamond and Precious Metal Geology Institute Russian Academy of SciencesSiberian Branch39Lenina Ave.Yakutsk 677000Russia

Although the diamond potential of cratons is linked mainly to thick and depleted Archean lithospheric keels, there are examples of craton-edge locations and circum-cratonic Proterozoic terranes underlain by diamondiferous mantle. Here, we use the results of comprehensive major and trace-element studies of detrital garnets from diamond-rich Late Triassic(Carnian) sedimentary rocks in the northeastern Siberia to constrain the thermal and chemical state of the pre-Triassic mantle and its ability to sustain the diamond storage. The studied detrital mantle-derived garnets are dominated by low-to mediumCr lherzolitic(~45%) and low-Cr megacrystic(~39%) chemistries, with a significant proportion of eclogitic garnets(~11%), and only subordinate contribution from harzburgitic garnets(~5%) with variable CrOcontents(1.2–8.4 wt.%). Low-Cr megacrysts display uniform, “normal” rare-earth element(REE)patterns with no Eu/Eu* anomalies, systematic Zr and Ti enrichment(mainly within 2.5–5), which are evidence of their crystallization from deep metasomatic melts. Lherzolitic(G9) garnets exhibit normal or humped to MREE-depleted sinusoidal REE patterns and elevated Nd/Y(up to 0.33–0.41) and Zr/Y ratios(up to 7.62). Rare low-to high-Cr harzburgitic(G10) garnets have.primarily “depleted”, sinusoidal REEpatterns, low Ti, Y and HREE, but vary significantly in Zr-Hf, Ti and MREE-HREE contents, Nd/Y(within 0.1–2.4) and Zr/Y(1.53–19.9) ratios. The observed trends of chemical enrichment from the most depleted,harzburgitic garnets towards lherzolitic(including high-Ti high-Cr G11-type) garnets and megacrysts result from either voluminous high-temperature metasomatism by plume-derived silicate melts or recurrent mobilization of less voluminous kimberlitic or related carbonated mantle melts, rather than the initially primitive, fertile nature of the Proterozoic SCLM. Calculated Ni-in-garnet temperatures(primarily within ~1150–1250 ℃) indicate their derivation from at least ~220 km thick Cr-undersa

关键词： Siberian craton Kimberlite Diamond placers Peridotites Eclogites Megacrysts

A new perspective on evolution of the Baikal Rift

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Geoscience Frontiers 2011年第3期2卷 349-365页

作者： Victor D.Mats Tatiana I.Perepelova 13/10 Shaar Hagay Str. Carmiel 20101Israel Limnological InstituteSiberian Branch of the RAS3 ul.Ulan-BatorskayaIrkutsk 664033Russia Sobolev Institute of Geology and Mineralogy Siberian Branch of the Russian Academy of Sciences3 Koptyug aveNovosibirsk 630090Russia

A new model is suggested for the history of the Baikal Rift, in deviation from the classic twostage evolution scenario, based on a synthesis of the available data from the Baikal Basin and revised correlation between tectonic-lithological-stratigraphic complexes （TLSC） in sedimentary sections around Lake Baikal and seismic stratigraphic sequences （SSS） in the lake sediments. Unlike the previous models, the revised model places the onset of rifting during Late Cretaceous and comprises three major stages which are subdivided into several substages. The stages and the substages are separated by events of tectonic activity and stress reversal when additional compression produced folds and shear structures. The events that mark the stage boundaries show up as gaps, unconformities, and deformation features in the deposition patterns. The earliest Late Cretaceous-Oligocene stage began long before the India-Eurasia collision in a setting of diffuse extension that acted over a large territory of Asia. The NW-SE far-field pure extension produced an NE-striking half-graben oriented along an old zone of weakness at the edge of the Siberian craton. That was already the onset of rift evolution recorded in weathered lacustrine deposits on the Baikal shore and in a wedge-shaped acoustically transparent seismic unit in the lake sediments. The second stage spanning Late Oligocene-Early Pliocene time began with a stress change when the effect from the Eocene India-Eurasia collision had reached the region and became a major control of its geodynamics. The EW and NE transpression and shear from the collisional front transformed the Late Cretaceous half-graben into a U-shaped one which accumulated a deformed layered sequence of sediments. Rifting at the latest stage was driven by extension from a local source associated with hot mantle material rising to the base of the rifted crust. The asthenospheric upwarp first induced the growth of the Baikal dome and the related change from finer

关键词： Sedimentary unit Tectonic phase Stress reversal Rifting mechanism Three-stage rift historyBaikal Rift

Comparison of mantle lithosphere beneath early Triassic kimberlite fields in Siberian craton reconstructed from deep-seated xenocrysts

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Geoscience Frontiers 2016年第4期7卷 639-662页

作者： I.V.Ashchepkov S.S.Kuligin N.V.Vladykin H.Downes M.A.Vavilov E.N.Nigmatulina S.A.Babushkina N.S.Tychkov O.S.Khmelnikova lnstitute of Geology and Mineralogy SD RAS Koptyug ave 3NovosibirskRussia Institute of Geochemistry SD RAS Favorskky str laIrkutskRussia Department of Earth and Planetary Sciences Birkbeck University of LondonLondonUK Institute of Geology of Diamonds and Noble metals SD RAS Lenina ave 39YakutskRussia

Mantle xenocrysts from early Triassic kimberlite pipes from Kharamai, Ary-Mastakh and Kuranakh fields in the Anabar shield of Siberia revealing similar compositional trends were studied to estimate the superplume influence on the subcratonic lithosphere mantle （SCLM）. Pressure-temperature （PT） reconstructions using monomineral thermobarometry for 5 phases show division of the SCLM beneath the Kharamai field into 6 units： pyroxenitic Fe-rich （1-2 GPa） and Mg-rich （2-3 GPa） layers; middle with two levels of Gar-Sp pyroxenites at - 3 and 4-5 GPa; Gar-dunite-harzburgites - 4.5-6.5 GPa subjected to llm-Px vein metasomatism; and a Mg-rich dunite lower part. In the Anabar shield （Ary-Mastakh, Dyuken and Kuranakh fields） mantle lithosphere is composed of three large units divided into two parts： upper part with amphiboles and phlogopite; two levels of pyroxenites and eclogites at 3 and 4 GPa, and a lower part composed of refertilized dunites. Diagrams showing P-Fe#Gar clusters for garnets and omphacites illustrate the differences between SCLM of these localities. Differences of Triassic SCLM from Devonian SCLM are in simple layering; abundance of Na-Cr-amphiboles and metasomatism in the upper SCLM part, thick pyroxenite-eclogite layer and lower part depletion, heated from SCLM base to 5.0 GPa. Kharamai mantle clinopyroxenes represent three geochemical types：（1） harzburgitic with inclined linear REE, HFSE troughs and elevated Th, U; （2） lherzolitic or pyroxenitic with round TRE patterns and decreasing incompatible elements; （3） eclogitic with Eu troughs, Pb peak and high LILE content. Calculated parental melts for garnets with humped REE patterns suggest dissolution of former Cpx and depression means Cpx and garnets extraction. Clinopyroxenes from Ary-Mastakh fields show less in- dined REE patterns with HMREE troughs and an increase of incompatible elements. Clinopyroxenes from Kuranakh field show flatter spoon-like REE patterns and peaks in Ba, U, Pb and St, similar to th

关键词： Mantle lithosphere Monomineral thermobarometry Mineral geochemistry Triassic kimberlite Layering

咸海演化的关键问题及其对经济、社会和生态价值的重要启示

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地学前缘 2021年第6期28卷 196-204页

作者： S.K.KRIVONOGOV T.I.KENSHINBAY R.Kh.KURMANBAEV B.S.KARIMOVA Novosibirsk State University Pirogova Str.1630090NovosibirskRussia Institute of geology and mineralogy SB RAS Koptyug Ave.3630090 NovosibirskRussia Korkyt-Ata Kyzylorda University Aiteke bi29a120000 KyzylordaRepublic of Kazakhstan

本文回顾了Aral Sea(咸海)海平面变化的最新认识,以供社会和经济项目决策者使用。我们提出了咸海生态标准的新认识:由于1960年之前当时的人类活动已经引起了湖泊萎缩,咸海在1960年之前是小到中型湖泊,而不是大型湖泊。对咸海认识的改变... 详细信息

本文回顾了Aral Sea(咸海)海平面变化的最新认识,以供社会和经济项目决策者使用。我们提出了咸海生态标准的新认识:由于1960年之前当时的人类活动已经引起了湖泊萎缩,咸海在1960年之前是小到中型湖泊,而不是大型湖泊。对咸海认识的改变可能会使许多基于极端情景的昂贵计划变得更加现实。同时,基于地质、考古、历史和水文研究中所获得的多重数据的综合分析,本次结果认为咸海在过去的2万年内经历了多次突然的海侵和海退。然而,除了现代的原因外,引起这些变化的原因的认识仍然不完整,需要进行专门的调查研究。在这篇论文中,我们针对水位变化、气候变化与咸海盆地来自锡尔河和阿姆河供水变化相结合的研究方法进行了讨论。

关键词：咸海湖平面变化气候变化水文变化

Physics and applications of charged domain walls

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npj Computational Materials 2018年第1期4卷 119-129页

作者： Petr S.Bednyakov Boris I.Sturman Tomas Sluka Alexander K.Tagantsev Petr V.Yudin Institute of Physics Czech Academy of SciencesNa Slovance 218221 Prague 8Czech Republic Institute of Automation and Electrometry SB RAS Koptyug ave.1Novosibirsk 630090Russia CREAL3D SA Chemin du Paqueret 1 ACH-1025 Saint-SulpiceSwitzerland Swiss Federal Institute of Technology(EPFL) CH-1015 LausanneSwitzerland Ioffe Institute 194021 St.PetersburgRussia

The charged domain wall is an ultrathin(typically nanosized)interface between two domains;it carries bound charge owing to a change of normal component of spontaneous polarization on crossing the *** contrast to hetero-interfaces between different materials,charged domain walls(CDWs)can be created,displaced,erased,and recreated again in the bulk of a *** of the bound charge with free carriers is often necessary for stability of CDWs,which can result in giant two-dimensional conductivity along the *** in nominally insulating ferroelectrics,the concentration of free carriers at the walls can approach metallic ***,CDWs can be viewed as ultrathin reconfigurable strongly conductive sheets embedded into the bulk of an insulating *** feature is highly attractive for future *** last decade was marked by a surge of research interest in *** resulted in numerous breakthroughs in controllable and reproducible fabrication of CDWs in different materials,in investigation of CDW properties and charge compensation mechanisms,in discovery of light-induced effects,and,finally,in detection of giant two-dimensional *** present review is aiming at a concise presentation of the main physical ideas behind CDWs and a brief overview of the most important theoretical and experimental findings in the field.

关键词： walls breakthrough nominal