152 research outputs found
Дефініції поняття “інтеграція” та його ролі в конкурентному ринковому процесі
Метою даної роботи є дослідження дефініцій розуміння інтеграційних процесів в аграрній сфері та їх ролі в конкурентному економічному середовищі
фольклорно-етнографічні матеріали на сторінках журналу «Основа»
In the article folk and ethnographical materials of the «Osnova» magazine are analyzed. The role of this edition in development of the ethnography is defined
Integrated gravity and topography analysis in analog models: Intraplate deformation in Iberia
Trends in the topography of the Iberian Peninsula show a pronounced contrast. In the western part of the Iberian microplate the main topographic highs trend E-W to NE-SW and are periodically spaced with wavelengths of 250 km. Conversely, in the northeastern part, the region of the Iberian Chain, topography is more irregular and strike directions vary from NW-SE to E-W and NE-SW. We relate this phenomenon to shortening of a continental lithosphere, which contains two different, well-defined domains of lithospheric strength. Our hypothesis is supported by physical analog models. A new processing method has been developed to assist the interpretation of the model results. It utilizes spectral analysis of gravity and topography data derived from the experiments. Folding of the crust and mantle lithosphere yields periodic gravity fluctuations, while thickening processes lead to localized gravity lows. In this way gravity data can be used to distinguish between the two forms of lithosphere deformation and to correlate areas that underwent the same type of deformation. Gravity modeling has been performed under full in-depth control of the experimental lithosphere structure. As such, gravity signals from the models may be compared to field gravity data for better understanding the underlying deformation mechanism.Peer reviewe
Analogue experiments on releasing and restraining bends and their application to the study of the Barents Shear Margin
The Barents Shear Margin separates the Svalbard and Barents Sea from the North Atlantic. During the break-up of the North Atlantic the plate tectonic configuration was characterized by sequential dextral shear, extension, and eventually contraction and inversion. This generated a complex zone of deformation that contains several structural families of overlapping and reactivated structures. A series of crustal-scale analogue experiments, utilizing a scaled and stratified sand-silicon polymer sequence, was used in the study of the structural evolution of the shear margin. The most significant observations for interpreting the structural configuration of the Barents Shear Margin are the following. Prominent early-stage positive structural elements (e.g. folds, push-ups) interacted with younger (e.g. inversion) structures and contributed to a hybrid final structural pattern. Several structural features that were initiated during the early (dextral shear) stage became overprinted and obliterated in the subsequent stages. All master faults, pull-apart basins, and extensional shear duplexes initiated during the shear stage quickly became linked in the extension stage, generating a connected basin system along the entire shear margin at the stage of maximum extension. The fold pattern was generated during the terminal stage (contraction-inversion became dominant in the basin areas) and was characterized by fold axes striking parallel to the basin margins. These folds, however, strongly affected the shallow intra-basin layers. The experiments reproduced the geometry and positions of the major basins and relations between structural elements (fault-and-fold systems) as observed along and adjacent to the Barents Shear Margin. This supports the present structural model for the shear margin
Post-5 Ma rock deformation on Alonnisos (Greece) constrains the propagation of the North Anatolian Fault
The localization of the North Anatolian Fault in the northern Aegean Sea (North Aegean Trough) is an intriguing example of continental transform fault propagation. Understanding this process critically depends on the quantification of strike-slip displacement and the superposition of normal and strike-slip faulting in the region, which is the aim of this study. In particular, we unravel and quantify normal and dextral faulting along the Alonnisos fault system, at the south-western margin of the North Aegean Trough (Sporades Basin). We present detailed structural data collected from Messinian strata of Alonnisos to infer the amount of post-5 Ma tilting and shortening on the island, and relate them to normal and dextral faulting along the Alonnisos fault system through simple analytical half-space models of dislocations. The Messinian rocks of Alonnisos record significant (13.5°) tilting and gentle folding close to the termination zone of the main fault segment. The tilting of the Messinian rocks was related to footwall uplift during normal faulting (in the order of 6–7 km vertical displacement) along the Alonnisos fault system, which implies that the deepening of the Sporades Basin occurred post-5 Ma. The post-Messinian folding accommodated ∼1 km shortening along the footwall termination zone of the Alonnisos fault and was related to 3–4 km dextral slip, possibly during the last 100–200 kyr. This is the first clear indication of major dextral displacement along the Alonnisos fault system. Our results support interpretations of currently distributed dextral strain in the North Aegean in response to the propagation of the North Anatolian Fault. However, similarities with the evolution of the Sea of Marmara might suggest that dextral shear could yet become fully localized in the NAT
“Круглий стіл” від 25 лютого 2011 року на тему: “Інформаційне суспільство: право, інновації та бізнес”
25 лютого 2011 року у приміщенні Київського регіонального центру Національної академії правових наук України Науково-дослідним центром правової інформатики НАПрН України спільно з Київським регіональним центром НАПрН України та Видавництвом “Академпрес” проведено засідання “круглого столу” на тему: “Інформаційне суспільство: право, інновації та бізнес”
From the Pyrenees to the Atlas: Topography and Analogue Modelling
El estudio de la Geología incorpora cada vez técnicas de estudio más depuradas y de última generación (ablación laser, estudio de huellas de fisión, métodos de prospección sísmica, etc.). Sin embargo, algunas de las metodologías más convencionales siguen siendo un recurso de primera mano en la interpretación de los procesos geológicos tanto internos como externos que llevan al modelado de la topografía.
Uno de estos ejemplos lo constituye la Modelación Análoga1, cuyos orígenes se remontan a principios del S.XIX. El fin último de este tipo de experimentos es el llegar a entender el por qué y el cómo en la formación de los relieves montañosos que observamos hoy en día, en nuestro caso aplicado a la Península Ibérica y su posible conexión con las cadenas montañosas que forman el Atlas marroquí. Este proceso podría estar relacionado con pliegues de gran longitud de onda que afectan a toda la litosfera.Earth Science integrates recent and new refined techniques (laser ablation, FT analyses, applied geophysics methods, etc). However, the most conventional methodologies still continue being relevant on the interpretation concerning both internal and external geodynamic processes that shape the landscape. Analogue Modelling was born in the beginning of the 19th Century and constitutes one of the main resources of geologic knowledge. We applied this technique to gain insight into the observable mountain building processes like those of the Iberian Peninsula and the connection with mountains that shapes the Moroccan Atlas. The process of mountain building might be linked to folding of the entire lithosphere.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEEspaña. Ministerio de Educación y Ciencia.pu
Plume‐Induced Sinking of Intracontinental Lithospheric Mantle: An Overlooked Mechanism of Subduction Initiation?
Although many different mechanisms for subduction initiation have been proposed, only few of them are viable in terms of consistency with observations and reproducibility in numerical experiments. In particular, it has recently been demonstrated that intra‐oceanic subduction triggered by an upwelling mantle plume could greatly contribute to the onset and operation of plate tectonics in the early and, to a lesser degree, modern Earth. On the contrary, the initiation of intra‐continental subduction still remains underappreciated. Here we provide an overview of 1) observational evidence for upwelling of hot mantle material flanked by downgoing proto‐slabs of sinking continental mantle lithosphere, and 2) previously published and new numerical models of plume‐induced subduction initiation. Numerical modeling shows that under the condition of a sufficiently thick (>100 km) continental plate, incipient downthrusting at the level of the lowermost lithospheric mantle can be triggered by plume anomalies of moderate temperatures and without significant strain‐ and/or melt‐related weakening of overlying rocks. This finding is in contrast with the requirements for plume‐induced subduction initiation within oceanic or thinner continental lithosphere. As a result, plume‐lithosphere interactions within continental interiors of Paleozoic‐Proterozoic‐(Archean) platforms are the least demanding (and thus potentially very common) mechanism for initiation of subduction‐like foundering in the Phanerozoic Earth. Our findings are supported by a growing body of new geophysical data collected in various intra‐continental areas. A better understanding of the role of intra‐continental mantle downthrusting and foundering in global plate tectonics and, particularly, in the initiation of “classic” ocean‐continent subduction will benefit from more detailed follow‐up investigations
Cenozoic deformation of Iberia: a model for intraplate mountain building and basin development based on analogue modelling
Inferences from analogue models support lithospheric folding as the primary response to large-scale shortening manifested in the present day topography of Iberia. This process was active from the late Oligocene-early Miocene during the Alpine orogeny and was probably enhanced by reactivation of inherited Variscan faults. The modeling results confirm the dependence of fold wavelength on convergence rate and hence the strength of the layers of the lithosphere such that fold wavelength is longest for fast convergence rates favoring whole lithosphere folding. Folding is associated with the formation of dominantly pop-up type mountain ranges in the brittle crust and thickening of the ductile layers in the synforms of the buckle folds by flow. The mountain ranges are represented by upper crustal pop-ups forming the main topographic relief. The wavelengths of the topographic uplifts, both, in model and nature suggest mechanical decoupling between crust and mantle. Moreover, our modeling results suggest that buckling in Iberia took place under rheological conditions where the lithospheric mantle is stronger than the lower crust. The presence of an indenter, inducing oblique shortening in response to the opening of the King's Trough in the north western corner of the Atlantic Iberian margin controls the spacing and obliquity of structures. This leads to the transfer of the deformation from the moving walls towards the inner part of the model, creating oblique structures in both brittle and ductile layers. The effect of the indenter, together with an increase on the convergence rate produced more complex brittle structures. These results show close similarities to observations on the general shape and distribution of mountain ranges and basins in Iberia, including the Spanish Central System and Toledo Mountains.Peer reviewe
Analogue modelling of basin inversion: a review and future perspectives
Basin inversion involves the reversal of subsidence in a basin due to
compressional tectonic forces, leading to uplift of the basin's sedimentary
infill. Detailed knowledge of basin inversion is of great importance for
scientific, societal, and economic reasons, spurring continued research
efforts to better understand the processes involved. Analogue tectonic
modelling forms a key part of these efforts, and analogue modellers have
conducted numerous studies of basin inversion. In this review paper we recap
the advances in our knowledge of basin inversion processes acquired through
analogue modelling studies, providing an up-to-date summary of the state of
analogue modelling of basin inversion. We describe the different definitions
of basin inversion that are being applied by researchers, why basin
inversion has been historically an important research topic and what the
general mechanics involved in basin inversion are. We subsequently treat the
wide range of different experimental approaches used for basin inversion
modelling, with attention to the various materials, set-ups, and techniques
used for model monitoring and analysing the model results. Our new systematic overviews of generalized model results reveal the diversity of these results, which depend greatly on the chosen set-up, model layering and
(oblique) kinematics of inversion, and 3D along-strike structural and
kinematic variations in the system. We show how analogue modelling results
are in good agreement with numerical models, and how these results help researchers to
better understand natural examples of basin inversion. In addition to
reviewing the past efforts in the field of analogue modelling, we also shed
light on future modelling challenges and identify a number of opportunities
for follow-up research. These include the testing of force boundary
conditions, adding geological processes such as sedimentation, transport, and
erosion; applying state-of-the-art modelling and quantification techniques;
and establishing best modelling practices. We also suggest expanding the
scope of basin inversion modelling beyond the traditional upper crustal
“North Sea style” of inversion, which may contribute to the ongoing search
for clean energy resources. It follows that basin inversion modelling can
bring valuable new insights, providing a great incentive to continue our
efforts in this field. We therefore hope that this review paper will form an
inspiration for future analogue modelling studies of basin inversion.</p
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