Geodynamics of Lithosphere and Earth’s Mantle: Seismic Anisotropy as a Record of the Past and Present Dynamic Processes   总被引：1，自引：0，他引：1  

Jaroslava Plomerová  Robert C. Liebermann  Vladislav Babuška 《Pure and Applied Geophysics》1998,151(2-4):213-219

  相似文献   

Lead Isotopic Composition in Biogenic Certified Reference Materials Determined by Different ICP‐based Mass Spectrometric Techniques          下载免费PDF全文

Jana Ďurišová  Lukáš Ackerman  Ladislav Strnad  Vladislav Chrastný  Jan Borovička 《Geostandards and Geoanalytical Research》2015,39(2):209-220

This work presents data for the radiogenic Pb isotopic ratios (²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb) in nine biogenic certified reference materials (NIST SRM 1515, 1566b, 1570a, 1573a, 1575a; BCR 100, BCR 101, BCR 670 and IAEA 359), which are suitable for analytical quality control in environmental research. The results were obtained using three different types of ICP‐based mass spectrometer (quadrupole‐based/magnetic sector field single‐collector ICP‐MS instruments and a multi‐collector ICP‐MS) and applying different mass bias correction procedures (calibrator‐sample bracketing and external Tl normalisation) with and without Pb separation from the matrix using ion exchange chromatography. In the majority of the samples, the measurements from all three of the ICP‐MS instruments were in agreement within ± 0.1%, despite the lower analytical precision of the single‐collector ICP‐MS instruments. We demonstrate that the presence of the sample matrix did not significantly influence the Pb isotopic ratios measured by magnetic sector field ICP‐MS, whereas the use of the two different mass bias corrections resulted in a systematic difference of 0.09% for the ²⁰⁸Pb/²⁰⁶Pb ratio.  相似文献   

Dynamics of “jumping” Trojans: a perturbative treatment     

Vladislav V. Sidorenko 《Celestial Mechanics and Dynamical Astronomy》2018,130(10):67

The term “jumping” Trojan was introduced by Tsiganis et al. (Astron Astrophys 354:1091–1100, 2000) in their studies of long-term dynamics exhibited by the asteroid (1868) Thersites, which had been observed to jump from librations around \(L_4\) to librations around \(L_5\). Another example of a “jumping” Trojan was found by Connors et al. (Nature 475:481–483, 2011): librations of the asteroid 2010 TK7 around the Earth’s libration point \(L_4\) preceded by its librations around \(L_5\). We explore the dynamics of “jumping” Trojans under the scope of the restricted planar elliptical three-body problem. Via double numerical averaging we construct evolutionary equations, which allow analyzing transitions between different regimes of orbital motion.  相似文献   

Event-scale pebble mobility observed by RFID tracking in a pre-Alpine stream: a field laboratory     

Vladislav Ivanov  Alessio Radice  Monica Papini  Laura Longoni 《地球表面变化过程与地形》2020,45(3):535-547

Understanding coarse sediment transport is crucial for the prediction of sediment migration and the consequent development of fluvial morphologies. In this study, cobble displacements in a pre-Alpine creek have been recorded by means of radio frequency identification (RFID). Pebble monitoring has been systematically performed after each rainfall event with moderate precipitation, in order to exclude the superimposition of sediment displacements induced by triggering factors acting at different times. The analysis of the collected data was carried out through the application of both a principal component analysis and the Buckingham Π theorem. The experimental trends were interpreted considering the ratio of mobile pebbles, the pebbles' displacement and virtual velocity as the dependent variables. These quantities mostly depend on the event peak discharge, with a nonlinear increase of the travelled distance and a growth of up to two orders of magnitude of the virtual velocity (for an approximately 10× increase in peak discharge). An inverse dependency of the virtual velocity on the event duration was also observed. A comparison of the results obtained with those from laboratory investigations of bedload transport mechanics evidenced the differences in parametric trends associated with sediment mobility in the two environments. This contrast brings forward the combination of multiple drivers of sediment mobility, such as local morphology, sediment dimensions and flow unsteadiness, warranting a further in-depth investigation. Representation of results in a dimensionless form is suggested as a good practice to analyse data from case studies characterized by different scales. © 2019 John Wiley & Sons, Ltd.  相似文献   

Comprehensive framework for gradient-based optimization in closed-loop reservoir management     

Vladislav Bukshtynov  Oleg Volkov  Louis J. Durlofsky  Khalid Aziz 《Computational Geosciences》2015,19(4):877-897

  相似文献   

The thermo-tectonic history of the Song-Kul plateau, Kyrgyz Tien Shan: Constraints by apatite and titanite thermochronometry and zircon U/Pb dating     

Johan De Grave  Stijn Glorie  Mikhail M. Buslov  Andrei Izmer  Alena Fournier-Carrie  Vladislav Yu. Batalev  Frank Vanhaecke  Marlina Elburg  Peter Van den haute 《Gondwana Research》2011,20(4):745-763

The Song-Kul Basin sits on a plateau at the Northern and Middle Kyrgyz Tien Shan junction. It is a lacustrine basin, occupied by Lake Song-Kul and predominantly developed on igneous basement. This basement was targeted for a multi-method chronological study to identify the different magmatic episodes responsible for basement formation and to constrain the timing of the development of its present-day morphology. Zircon U/Pb dating by LA-ICP-MS revealed four different magmatic episodes: a Late Cambrian (~ 500 Ma) island arc system, a Late Ordovician (~ 450 Ma) subduction related intrusion, an Early Permian (~ 290 Ma) collisional stage, and a Middle to Late Permian (~ 260 Ma) post-collisional magmatic pulse. Middle to Late Triassic (~ 200–230 Ma) titanite fission-track ages and Late Triassic – Early Jurassic (~ 180–210 Ma) apatite fission-track ages and thermal history modeling indicate the Song-Kul basement was already emplaced in the shallow crust at that time. An exhumed fossil apatite fission-track partial annealing zone is recognized in the bordering Song-Kul mountain ranges. The area experienced only minor post-Early Mesozoic denudation. The igneous basement was slowly brought to apatite (U–Th)/He retention temperatures in the Late Cretaceous–Palaeogene. Miocene to present reactivation of the Tien Shan does not manifestly affect this part of the orogen.  相似文献   

Thermo-tectonic history of the Issyk-Kul basement (Kyrgyz Northern Tien Shan,Central Asia)     

Johan De Grave  Stijn Glorie  Mikhail M. Buslov  Daniel F. Stockli  Michael O. McWilliams  Vladislav Yu. Batalev  Peter Van den haute 《Gondwana Research》2013,23(3):998-1020

Lake Issyk-Kul occupies a large Late Mesozoic–Cenozoic intramontane basin between the mountain ranges of the Northern Kyrgyz Tien Shan. These ranges are often composed of granitoid basement that forms part of a complex mosaic assemblage of microcontinents and volcanic arcs. Several granites from the Terskey, Kungey, Trans-Ili and Zhetyzhol Ranges were dated with the zircon U/Pb method (SHRIMP, LA-ICP-MS) and yield concordant Late Ordovician–Silurian (~ 456–420 Ma) emplacement ages. These constrain the “Caledonian” accretion history of the Northern Kyrgyz Tien Shan in the amalgamated Palaeo-Kazakhstan continent. The ancestral Tien Shan orogen assembled in the Early Permian when final closure of the Turkestan Ocean ensued collision of Palaeo-Kazakhstan and Tarim. A Late Palaeozoic structural basement fabric formed and Middle–Late Permian post-collisional magmatism added to crustal growth of the Tien Shan. Permo‐Triassic cooling (~ 300–220 Ma) of the ancestral Tien Shan was unraveled using ⁴⁰Ar/³⁹Ar K-feldspar and titanite fission-track (FT) thermochronology on the Issyk-Kul granitoids. Apatite thermochronology (FT and U–Th–Sm/He) applied to the broader Issyk-Kul region elucidates the Meso-Cenozoic thermo-tectonic evolution and constrains several tectonic reactivation episodes in the Jurassic, Cretaceous and Cenozoic. Exhumation of the studied units occurred during a protracted period of intracontinental orogenesis, linked to far-field effects of Late Jurassic–Cretaceous accretion of peri-Gondwanan blocks from the Tethyan realm to Eurasian. Following a subsequent period of stability and peneplanation, incipient building of the modern Tien Shan orogen in Northern Kyrgyzstan started in the Oligocene according to our data. Intense basement cooling in distinct reactivated and fault-controlled sections of the Trans-Ili and Terskey Ranges finally pinpoint important Miocene–Pliocene (~ 22–5 Ma) exhumation of the Issyk-Kul basement. Late Cenozoic formation of the Tien Shan is associated with ongoing indentation of India into Eurasia and is a quintessential driving force for the reactivation of the entire Central Asian Orogenic Belt.  相似文献   

Comment on the Seismic Method Depth-Recursive Tomography on Grid (DRTG) Developed by Miroslav Novotný and Recently Published in Three Papers in Surveys in Geophysics     

Pavla Hrubcová  Piotr Środa  Václav Vavryčuk  Vladislav Babuška  Marek Grad 《Surveys in Geophysics》2013,34(4):521-529

  相似文献   

The Sorgenfrei–Tornquist Zone as the mantle edge of Baltica lithosphere: new evidence from three-dimensional seismic anisotropy     

Vladislav Babu&#;ka  Jaroslava Plomerová 《地学学报》2004,16(5):243-249

Joint analysis of shear‐wave splitting parameters and directional dependence of teleseismic P residuals based on data from the seismic experiment TOR across the Trans‐European Suture Zone suggest that the Sorgenfrei–Tornquist Zone (STZ) in northern Denmark forms the south‐western margin of Baltica in the upper mantle. Different lithosphere thickness and different orientation of seismic anisotropy in the mantle lithosphere identify three domains separated by the STZ between Denmark and southern Sweden and the Thor Suture between northern Germany and Denmark. We suggest that the anisotropy reflects frozen‐in olivine fabrics, most probably created during early stages of the evolution of the European continent. The middle Danish block might represent a microplate caught in between Avalonia and Baltica before the Caledonian orogeny.  相似文献   

古新世特提斯北缘前黑海地区盆地的演化与油气远景   总被引：1，自引：0，他引：1  

B. M. 波诺托维奇  O. V. 萨马斯加  V. Yu. 塔柯维斯基 《沉积与特提斯地质》1997,17(4):40-49

本文以ＥＸＸＯＮ公司Ｐ．Ｒ．Ｖａｉｌ等人创立的层序地层学理论为准，对华南泥盆系的层序地层进行了区域上的研究、分析、对比。研究结果表明，从下泥盆统的洛赫科夫阶至上泥盆统的法门阶可识别出２０～２１个Ⅲ级层序。华南泥盆系的岩石地层、生物地层、年代地层的系、统、阶界线均已确定，与层序地层研究结果对比，生物地层界线均比相应的层序地层界线滞后。本文试图以层序地层序列为准，建立一新的地层系统作为相应的生物地层、年代地层的系、统、阶相对应的辅助性地层系统。研究结果表明，在岩石地层、生物地层、年代地层研究程度高的地区，可建立层序地层的系、统、阶界线系统以利于野外作业。华南地区的泥盆系内，除弗拉斯阶与法门阶的阶间界线置于饥饿层（ｓｔａｒｖｅｄｓｅｃｔｉｏｎ）外，其他的阶、统、系界线均位于有关阶（统）顶部层序中的ＨＳＴ的顶面。  相似文献