排序方式: 共有14条查询结果,搜索用时 15 毫秒
1.
Walter Capella Wim Spakman Douwe J. J. van Hinsbergen Mariya V. Chertova Wout Krijgsman 《地学学报》2020,32(2):141-150
The Messinian Salinity Crisis (5.97–5.33 Ma) was caused by the closure of the Atlantic‐Mediterranean gateways that cut through the Gibraltar orogenic system. The geodynamic drivers underlying gateway closure and re‐opening are still debated. Here, we interrogate the gateway successions to find the imprints of surface deformation, infer the timing and nature of associated geodynamic drivers, and test such inferences against numerical simulations of slab dynamics. We find that since the latest Miocene, a tectonic framework was established in the gateway region dominated simultaneously by (a) relative plate convergence, (b) slab tearing under the eastern Betic Cordillera and (c) mantle resistance against north‐northeastward dragging of the Gibraltar slab by the African plate's absolute motion. We propose that mantle‐resisted slab dragging and slab tearing operated in concert closing the gateways that caused the Messinian Salinity Crisis, whereas sinking of heavy oceanic lithosphere located between buoyant continental plates re‐opened the Strait of Gibraltar at 5.33 Ma. 相似文献
2.
Krylov Alexey A. Hachikubo Akihiro Minami Hirotsugu Pogodaeva Tatyana V. Zemskaya Tamara I. Krzhizhanovskaya Mariya G. Poort Jeffrey Khlystov Oleg M. 《International Journal of Earth Sciences》2018,107(6):2011-2022
International Journal of Earth Sciences - Early diagenetic carbonates are rare in Lake Baikal. Siderite (Fe carbonate) concretions in the sediments were discovered only recently. Here, we discuss... 相似文献
3.
Mariya I. Yurkina 《Studia Geophysica et Geodaetica》1994,38(4):325-332
Summary A relation is established between coefficients of an expansion of the gravitational potential into a series of Legendre's
function of the second kind and coefficients of an expansion of gravity anomalies on the surface of the reference ellipsoid
into a series of the same functions. This connection can be useful in geodetic computations which take into account the Earth's
flattening. 相似文献
4.
Alexander G. Sokol Yury N. Palyanov Igor N. Kupriyanov Mariya P. Polovinka 《Geochimica et cosmochimica acta》2010,74(16):4793-4806
High pressure experiments have been performed in the systems Mg2SiO4-C-O-H and Mg2SiO4-K2CO3-C at 6.3 GPa and 1200 to 1600 °C using a split-sphere multi-anvil apparatus. In the Mg2SiO4-C-O-H system the composition of fluid was modeled by adding different amounts of water and stearic acid. The fO2 was controlled by the Mo-MoO2 or Fe-FeO oxygen buffers. Several experiments in the Mg2SiO4-C-O-H system and all experiments in the Mg2SiO4-K2CO3-C system have been conducted without buffering the fO2. Forsterite in the system Mg2SiO4-K2CO3-C does not reveal OH absorption bands in the IR spectra, while forsterite coexisting with carbon-bearing fluid and silicate melt at logfO2 from FMQ-2 to FMQ-5 (from 2 to 5 log units below fayalite-magnetite-quartz oxygen buffer) contains 800-1850 wt. ppm H2O. The maximum concentrations were detected at 1400 °C and FMQ-3.5. We observed an increase in the solidus temperature in the system Mg2SiO4-C-O-H from 1200 to above 1600 °C with log fO2 decreasing from FMQ-2 to FMQ-5. The increase of the solidus temperature and the broadening of the stability field of the H2O-H2-CH4 subsolidus fluid phase at 1400-1600 °C explain the high H2O storage capacity of forsterite relative to that crystallized from carbon-free, oxidized, hydrous, silicic melt. At temperatures above 1400 °C liquidus forsterite precipitated along with diamond from oxidized (FMQ-1) carbonate-silicate melt and from silicate melt dissolving the moderately reduced C-O-H fluid (from FMQ-2 to FMQ-3.5). Formation of diamond was not detected under ultra-reduced conditions (FMQ-5) at 1200-1600 °C. Olivine co-precipitating with diamond from dry carbonate-silicate or hydrous-silicic fluid/melt can provide information on the H2O contents and speciation of the diamond-forming media in the mantle. The conditions for minimum post-crystallization alteration of olivine and its hydrogen content are discussed. 相似文献
5.
Shchukina Elena V. Agashev Aleksey M. Soloshenko Natalia G. Streletskaya Mariya V. Zedgenizov Dmitry A. 《Mineralogy and Petrology》2019,113(5):593-612
Mineralogy and Petrology - In this paper, new main and trace elements and isotopic data are presented for 14 coarse-grained eclogite xenoliths from the V. Grib kimberlite pipe in the central part... 相似文献
6.
New data from recent surveys investigating the geochemistry of light hydrocarbons over a 4-year period in the Chernomorneftegaz petroleum license area in the central Sea of Azov are presented in this paper. The distributions of light hydrocarbons in both marine sediments and seawater were studied, and stable anomalies of hydrocarbons detected. Based on complex interpretations of geochemical and geophysical data, it has been shown that migration from the deep part of the sediment cover to the surface (seabed) is the main factor which determines the spatial distribution of hydrocarbons in the modern seabed sediments and seawater. The contribution of microbial and anthropogenic processes is insignificant. 相似文献
7.
Mariya I. Yurkina 《Studia Geophysica et Geodaetica》1996,40(1):9-13
Summary On the basis of the fundamental relations of the Molodensky's Earth's figure theory (1945), admitting the inequality of the
gravity potentials at the Major Vertical Datum W0 and on the surface of the reference level ellipsoid U0, and taken into account that potential W0 enters into equations directly, it is recomended, W0 should be adopted as a primary geodetic constant. Parameters of the best fitting ellipsoid are not needed for the solution
of geodetic problems and for the investigation of the Earth's gravity field. The reason for requiring the reference and actual
fields be close is only that the boundary-value problem can be solved in the linear approximation.
Dedicated to the Memory of M.S. Molodensky
Contribution to the I.A.G. Special Commission SC3 Fundamental Constants (SCFC). 相似文献
8.
Determination of Stokes' constants respecting zero -frequency tidal term due to the Moon and the Sun
Mariya I. Yurkina 《Studia Geophysica et Geodaetica》1993,37(4):317-325
Summary A principle of determining the Earth's gravitational field through the Stokes' constants is presented. The problem is properly posed according to Hadamard. The zero-frequency tidal terms due to the Moon and the Sun are introduced analytically into the absolute terms of equations. The ellipsoidal coordinates are used. The reference field should be so close to the actual one, that the problem can be solved in a linear approximation. The proximity of the fields mentioned does not need to be of the highest possible degree.Contribution to the I.A.G. Special Commission SC3 Fundamental Constants (SCFC) 相似文献
9.
Mariya I. Yurkina 《Studia Geophysica et Geodaetica》1995,39(1):11-18
Summary The application of Euler's postulate
, which determines rotation (here
denotes the derivative of the angular momentum with respect to time, L the resultant torque of exterior forces relative to the centre of inertia), to a celestial body, which is not spherically symmetric, had aroused doubts in Euler himself because of the displacement of the resultant attractive force of other celestial bodies from the said centre. As Minding had noted, it is more logical to compute the resultant torque relative to a point at which the torque has a minimum. This point should be named the attrahentis centrum after Euler. Newton was aware of this displacement of the resultant force and had mentioned it in the Principia. A review of Euler's works connected with this subject is given. 相似文献
10.
Emanouil Atanassov Aneta Karaivanova Todor Gurov Sofiya Ivanovska Mariya Durchova Dimitar Sl. Dimitrov 《Earth Science Informatics》2010,3(4):289-296
In this paper we present error and performance analysis of quasi-Monte Carlo algorithms for solving multidimensional integrals
(up to 100 dimensions) on the grid using MPI. We take into account the fact that the Grid is a potentially heterogeneous computing
environment, where the user does not know the specifics of the target architecture. Therefore parallel algorithms should be
able to adapt to this heterogeneity, providing automated load-balancing. Monte Carlo algorithms can be tailored to such environments,
provided parallel pseudorandom number generators are available. The use of quasi-Monte Carlo algorithms poses more difficulties.
In both cases the efficient implementation of the algorithms depends on the functionality of the corresponding packages for
generating pseudorandom or quasirandom numbers. We propose efficient parallel implementation of the Sobol sequence for a grid
environment and we demonstrate numerical experiments on a heterogeneous grid. To achieve high parallel efficiency we use a
newly developed special grid service called Job Track Service which provides efficient management of available computing resources through reservations. 相似文献