Hydraulic Fracturing of Heterogeneous Rock Monitored by Acoustic Emission     

Sergey Stanchits  Jeffrey Burghardt  Aniket Surdi 《Rock Mechanics and Rock Engineering》2015,48(6):2513-2527

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Möhnite, (NH4)K2Na(SO4)2, a new guano mineral from Pabellón de Pica,Chile     

Nikita V. Chukanov  Sergey M. Aksenov  Ramiza K. Rastsvetaeva  Igor V. Pekov  Dmitry I. Belakovskiy  Sergey N. Britvin 《Mineralogy and Petrology》2015,109(5):643-648

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Odyssey of Aleutian eddies     

Budyansky  Maxim V.  Prants  Sergey V.  Uleysky  Michael Yu 《Ocean Dynamics》2022,72(6):455-476

Ocean Dynamics - Long-lived and large-scale anticyclonic Aleutian eddies (AEs), detaching from the Alaskan Stream to the west of 180∘ and propagating southwestward or almost zonally in the...  相似文献   

Recent Russian remote sensing investigations in Antarctica within the framework of scientiifc traverses     

Sergey V.Popov 《极地研究(英文版)》2015,(2)

This paper includes a short historical review of Russian and Soviet scientiifc traverses to study the Antarctic inland. The ifrst traverse left on April 2, 1956. It resulted in the opening of the ifrst...  相似文献   

Archaean Kuru-Vaara eclogites in the northern Belomorian Province,Fennoscandian Shield: crustal architecture,timing, and tectonic implications     

Victor Balagansky  Andrey Shchipansky  Alexander I. Slabunov  Il’ya Gorbunov  Sergey Mudruk  Mikhail Sidorov 《International Geology Review》2015,57(11-12):1543-1565

This paper addresses the relationships between relic amphibole-eclogite facies (AE) eclogites and their host units, Archaean amphibolites, enveloped by Archaean tonalite–trondhjemite–granodiorite (TTG) gneisses, in the Kuru-Vaara study area in the northern Belomorian Province. According to observational constraints, the crystallization of the relic peak omphacite + Mg-garnet ± kyanite assemblage and the subsequent replacement of omphacite by clinopyroxene–plagioclase symplectite occurred before the earliest deformational, metamorphic, and migmatization events that are recorded in the amphibolites. The amphibolites and their TTG hosts have a shared deformational and metamorphic history that is composed of the Archaean and Palaeoproterozoic periods. This history favours the conclusion that the AE metamorphism recorded in the relic eclogites within the amphibolites occurred during the Mesoarchaean to Neoarchaean periods. The deformation and metamorphism of the amphibolite facies of the second period resulted from the Lapland–Kola collisional orogeny at 1.91–1.93 Ga, which led to eclogite–high-pressure granulite (E–HPG) facies conditions in the lowermost portions of the over-thickened crust in Belomorian Province (the southwestern foreland of the Lapland–Kola collisional orogen). The Palaeoproterozoic E–HPG overprint was reported from the Palaeoproterozoic Gridino mafic dikes. Although the ages of the oldest low Th/U zircons are close to the time of the Lapland–Kola collision, the low Th/U 1.9–1.8 Ga zircons reflect a zircon response to regional fluid infiltration in the eclogites during slow exhumation following the Lapland–Kola orogeny and do not record any metamorphic event. Contrary to the Palaeoproterozoic E–HPG overprint, the areal occurrence of the 2.7–2.8 Ga AE eclogites with mid-ocean ridge basalt-like chemistry and their paragenetic link with the TTG gneisses suggest a tectonic regime that involves subduction. This research favours concepts suggesting that the modern-style plate tectonics has operated in some places, at least since the late Mesoarchaean.  相似文献   

Nickelpicromerite,K<Subscript>2</Subscript>Ni(SO<Subscript>4</Subscript>)<Subscript>2</Subscript>•6H<Subscript>2</Subscript>O,a new picromerite-group mineral from Slyudorudnik,South Urals,Russia     

Elena?V.?BelogubEmail author  Sergey?V.?Krivovichev  Igor?V.?Pekov  Aleksey?M.?Kuznetsov  Vasiliy?O.?Yapaskurt  Vasiliy?A.?Kotlyarov  Nikita?V.?Chukanov  Dmitry?I.?Belakovskiy 《Mineralogy and Petrology》2015,109(2):143-152

A new picromerite-group mineral, nickelpicromerite, K₂Ni(SO₄)₂?·?6H₂O (IMA 2012–053), was found at the Vein #169 of the Ufaley quartz deposit, near the town of Slyudorudnik, Kyshtym District, Chelyabinsk area, South Urals, Russia. It is a supergene mineral that occurs, with gypsum and goethite, in the fractures of slightly weathered actinolite-talc schist containing partially vermiculitized biotite and partially altered sulfides: pyrrhotite, pentlandite, millerite, pyrite and marcasite. Nickelpicromerite forms equant to short prismatic or tabular crystals up to 0.07 mm in size and anhedral grains up to 0.5 mm across, their clusters or crusts up to 1 mm. Nickelpicromerite is light greenish blue. Lustre is vitreous. Mohs hardness is 2–2½. Cleavage is distinct, parallel to {10–2}. D _meas is 2.20(2), D _calc is 2.22 g cm^?3. Nickelpicromerite is optically biaxial (+), α?=?1.486(2), β?=?1.489(2), γ?=?1.494(2), 2V_meas =75(10)°, 2V_calc =76°. The chemical composition (wt.%, electron-microprobe data) is: K₂O 20.93, MgO 0.38, FeO 0.07, NiO 16.76, SO₃ 37.20, H₂O (calc.) 24.66, total 100.00. The empirical formula, calculated based on 14 O, is: K_1.93Mg_0.04Ni_0.98S_2.02O_8.05(H₂O)_5.95. Nickelpicromerite is monoclinic, P2₁/c, a?=?6.1310(7), b?=?12.1863(14), c?=?9.0076(10) Å, β?=?105.045(2)°, V?=?649.9(1) ų, Z?=?2. Eight strongest reflections of the powder XRD pattern are [d,Å-I(hkl)]: 5.386–34(110); 4.312–46(002); 4.240–33(120); 4.085–100(012, 10–2); 3.685–85(031), 3.041–45(040, 112), 2.808–31(013, 20–2, 122), 2.368–34(13–3, 21–3, 033). Nickelpicromerite (single-crystal X-ray data, R?=?0.028) is isostructural to other picromerite-group minerals and synthetic Tutton’s salts. Its crystal structure consists of [Ni(H₂O)₆]²⁺ octahedra linked to (SO₄)^2? tetrahedra via hydrogen bonds. K⁺ cations are coordinated by eight anions. Nickelpicromerite is the product of alteration of primary sulfide minerals and the reaction of the acid Ni-sulfate solutions with biotite.  相似文献   

Accounting for natural-climatic conditions in the design of roads in western Siberia     

Vladimir N. Efimenko  Sergey V. Efimenko  Alexey V. Sukhorukov 《寒旱区科学》2015,7(4):307-315

The paper proposes a methodological scheme that thoroughly accounts for natural-climatic conditions which can impair the stability and longevity of transport facilities (roadways), to ensure the best possible quality of the initial road design. Factors determining the formation of water-heating mode subgrade soils are allocated, and an information database for mathematical modeling of geocomplexes is shown. Values of strength and deformability of clay soils are calculated within the limits of the defined, homogeneous road districts in Western Siberia to provide the required level of reliability of design solutions.  相似文献   

A seismically triggered landslide dam in Honshiyan,Yunnan, China: from emergency management to hydropower potential   总被引：1，自引：1，他引：0  

Shaojie Zhang  Xiangping Xie  Fangqiang Wei  Sergey Chernomorets  Dmitry Petrakov  Irina Pavlova  Ricardo Delgado Tellez 《Landslides》2015,12(6):1147-1157

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The synergy of earthquake precursors     

Sergey Pulinetst 《地震学报(英文版)》2011,(6):535-548

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Angle gathers in wave‐equation imaging for transversely isotropic media     

Tariq Alkhalifah  Sergey Fomel 《Geophysical Prospecting》2011,59(3):422-431

In recent years, wave‐equation imaged data are often presented in common‐image angle‐domain gathers as a decomposition in the scattering angle at the reflector, which provide a natural access to analysing migration velocities and amplitudes. In the case of anisotropic media, the importance of angle gathers is enhanced by the need to properly estimate multiple anisotropic parameters for a proper representation of the medium. We extract angle gathers for each downward‐continuation step from converting offset‐frequency planes into angle‐frequency planes simultaneously with applying the imaging condition in a transversely isotropic with a vertical symmetry axis (VTI) medium. The analytic equations, though cumbersome, are exact within the framework of the acoustic approximation. They are also easily programmable and show that angle gather mapping in the case of anisotropic media differs from its isotropic counterpart, with the difference depending mainly on the strength of anisotropy. Synthetic examples demonstrate the importance of including anisotropy in the angle gather generation as mapping of the energy is negatively altered otherwise. In the case of a titled axis of symmetry (TTI), the same VTI formulation is applicable but requires a rotation of the wavenumbers.  相似文献