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51.
Study of tectono-geodynamic clusters of the continental lithosphere (the Sloboda cluster of the East European Platform and the Pamir cluster of Central Asia) permitted identification of pool structures, which are a specific type of zone of intraplate interaction of rock masses. 相似文献
52.
M. G. Leonov 《Geotectonics》2013,47(6):439-451
In the course of reconstructing the geodynamic evolution of certain regions and structures, it is pointed out that the formation algorithm, which operates for a long time, abruptly changes unaffected by any obvious factor: a thermal event, collision of lithospheric plates, etc. It is suggested that the sharp change in the geological evolution algorithm is related to accumulation of the energy potential, the relaxation of which is initiated by a trigger mechanism that leads to realization of the stored energy in a new form. Several geodynamic situations, the origin and development of which are related to the trigger mechanism, are considered in the paper: morphostructural subdivision of paleobasins, interaction of deformation and metamorphism, vertical accretion of a granitic-metamorphic layer, and development of horizontal protrusions (plate flows) in the Earth’s lithosphere. 相似文献
53.
Jacopo Cabassi Franco Tassi Orlando Vaselli Jens Fiebig Matteo Nocentini Francesco Capecchiacci Dmitri Rouwet Gabriele Bicocchi 《Bulletin of Volcanology》2013,75(1):1-19
This paper focuses on the chemical and isotopic features of dissolved gases (CH4 and CO2) from four meromictic lakes hosted in volcanic systems of Central–Southern Italy: Lake Albano (Alban Hills), Lake Averno (Phlegrean Fields), and Monticchio Grande and Piccolo lakes (Mt. Vulture). Deep waters in these lakes are characterized by the presence of a significant reservoir of extra-atmospheric dissolved gases mainly consisting of CH4 and CO2. The δ13C-CH4 and δD-CH4 values of dissolved gas samples from the maximum depths of the investigated lakes (from ?66.8 to ?55.6?‰ V-PDB and from ?279 to ?195?‰ V-SMOW, respectively) suggest that CH4 is mainly produced by microbial activity. The δ13C-CO2 values of Lake Grande, Lake Piccolo, and Lake Albano (ranging from ?5.8 to ?0.4?‰ V-PDB) indicate a significant CO2 contribution from sublacustrine vents originating from (1) mantle degassing and (2) thermometamorphic reactions involving limestone, i.e., the same CO2 source feeding the regional thermal and cold CO2-rich fluid emissions. In contrast, the relatively low δ13C-CO2 values (from ?13.4 to ?8.2?‰ V-PDB) of Lake Averno indicate a prevalent organic CO2. Chemical and isotopic compositions of dissolved CO2 and CH4 at different depths are mainly depending on (1) CO2 inputs from external sources (hydrothermal and/or anthropogenic); (2) CO2–CH4 isotopic exchange; and (3) methanogenic and methanotrophic activity. In the epilimnion, vertical water mixing, free oxygen availability, and photosynthesis cause the dramatic decrease of both CO2 and CH4 concentrations. In the hypolimnion, where the δ13C-CO2 values progressively increase with depth and the δ13C-CH4 values show an opposite trend, biogenic CO2 production from CH4 using different electron donor species, such as sulfate, tend to counteract the methanogenesis process whose efficiency achieves its climax at the water–bottom sediment interface. Theoretical values, calculated on the basis of δ13C-CO2 values, and measured δ13CTDIC values are not consistent, indicating that CO2 and the main carbon-bearing ion species (HCO3 ?) are not in isotopic equilibrium, likely due to the fast kinetics of biochemical processes involving both CO2 and CH4. This study demonstrates that the vertical patterns of the CO2/CH4 ratio and of δ13C-CO2 and δ13C-CH4 are to be regarded as promising tools to detect perturbations, related to different causes, such as changes in the CO2 input from sublacustrine springs, that may affect aerobic and anaerobic layers of meromictic volcanic lakes. 相似文献
54.
Current visualization techniques for computational fluid dynamics applications are sophisticated and work well in simple geometries. For complex geometries such as pore spaces, multiple domain boundaries obstruct the view and make the studying of fluid flow fields difficult. To overcome these deficiencies, we use two-sided materials to render the domain boundaries. Using this technique, it is possible to place the camera inside the domain and have a non-obstructed view of the surrounding flow field without losing spatial reference to the domain boundaries. As a result, a larger part of fluid flow visualization is visible. Two-sided material rendering was successfully applied to display still images with Blender Cycles renderer, in a virtual reality environment, and several implementation techniques were explored for using the Visualization Toolkit. 相似文献
55.
Lars Bilke Thomas Fischer Carolin Helbig Charlotte Krawczyk Thomas Nagel Dmitri Naumov Sebastian Paulick Karsten Rink Agnes Sachse Sophie Schelenz Marc Walther Norihiro Watanabe Björn Zehner Jennifer Ziesch Olaf Kolditz 《Environmental Earth Sciences》2014,72(10):3881-3899
Scientific visualization is an integral part of the modeling workflow, enabling researchers to understand complex or large data sets and simulation results. A high-resolution stereoscopic virtual reality (VR) environment further enhances the possibilities of visualization. Such an environment also allows collaboration in work groups including people of different backgrounds and to present results of research projects to stakeholders or the public. The requirements for the computing equipment driving the VR environment demand specialized software applications which can be run in a parallel fashion on a set of interconnected machines. Another challenge is to devise a useful data workflow from source data sets onto the display system. Therefore, we develop software applications like the OpenGeoSys Data Explorer, custom data conversion tools for established visualization packages such as ParaView and Visualization Toolkit as well as presentation and interaction techniques for 3D applications like Unity. We demonstrate our workflow by presenting visualization results for case studies from a broad range of applications. An outlook on how visualization techniques can be deeply integrated into the simulation process is given and future technical improvements such as a simplified hardware setup are outlined. 相似文献
56.
M. G. Leonov Yu. G. Tsekhovskii E. S. Przhiyalgovskii A. V. Poleshchuk E. V. Lavrushina 《Lithology and Mineral Resources》2014,49(1):81-102
Disintegrated granitoids, which frequently enclose abundant clastic material of the same rocks, are widespread in the upper parts of the Earth’s crust. They occur both on the surface and under the thick sedimentary cover. Two processes are responsible for the formation of such rocks: supergenic (chemical and physical weathering) and tectonic (prototectonics and posthumous disintegration). These processes result in the formation of similar (in compositions, textures, and attitude) clastic rocks, which complicates the interpretation of their genesis in particular situations. In this work, we discuss processes of the exogenic and tectonic disintegration of granitoids, structure of disintegrated rocks, and mineral transformations. Typomorphic features of the disintegrated granitoids related to tectonic and exogenic processes are compared. 相似文献
57.
The paper describes tectonic assemblies determining structure and kinematics of the plate evolution in the eastern segment of the Gobi Altay and Gobi Tien Shan intraplate reactivation zones in southern Mongolia. These zones are characterized by deformations corresponding to a 3D brittle-ductile shear flow. The structural and compositional reworking is most strikingly expressed in certain varieties of granites, which form specific geostructures called crystalline protrusions. The internal structure of protrusive bodies is distinguished by fragmentation differing in scale, intense brecciation, cataclasis, and structural-mineral reworking of rocks. Taken together, these phenomena facilitate the tectonic mobility of rock masses under low-temperature and hypabyssal conditions and maintain 3D tectonic flow in basement rocks. The tectonic style of the region and its evolution are predetermined by the 3D flow of granitoids in the crystalline basement, which is related to the joint action of various mechanisms discussed in this paper. 相似文献
58.
The observations on ground-based facilities miss multitudes of small fragments of space debris. However, the intrusion of
fine particles into the atmosphere and their subsequent burning can be observed along with the usual meteor phenomena. Since
the solar system meteoric body velocities at the entry into the atmosphere are over 11.2 km/s, and the velocity of the space
debris objects does not exceed 11.2 km/s, the selection of meteors by velocity is a reliable criterion for separating these
bodies. The paper describes a method of selecting the space debris fragments using a technique of television meteor monitoring.
The technique was adapted on the material of real television observations on the FAVOR wide-field monitoring camera with high
temporal resolution, conducted in 2006 in the Arkhyz station of the Institute for Precision Instrumentation (North Caucasus). 相似文献
59.
Andrey V. Leonov 《The Cartographic journal》2013,50(3):235-255
The article describes the evolution of the cartography and toponymy of the second largest geyser field in the world – the Valley of Geysers in the Kronotsky Reserve (Kamchatka Peninsula, Russia), discovered in 1941. The toponymy evolved in close connection with the development of the cartographic base that passed through the three stages from the first manual drawings to large-scale maps and to 3D models of the territory. The number of geysers with personal names increased gradually from twelve to more than one hundred. The article presents examples of diagrams and maps as well as tables of thermal features with coordinates. All main sources of literature were analysed for the period of 1941–2017, and the article presents a comprehensive historiography on the investigated topic. The evolution of instruments for the measurement of geyser activity is also briefly overviewed with examples of data obtained using the different methods. 相似文献
60.
The first finding of prints of the Vendian Beltanelloides sorichevae Sokolov 1965 in the lower part of the Barakun Formation confirms the Vendian age of the Far Taiga Group, Patom Complex. This finding also raises a problem concerning the lower propagation limit of Beltanelloides sorichevae. 相似文献