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1
Rands, Peter N. "European geodynamics using satellite geodesy." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316076.
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Toth, John. "Geodynamics of the Central Andes." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262590.
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Ingle, Stéphanie. "Chemical geodynamics of the early kerguelen plume." Doctoral thesis, Universite Libre de Bruxelles, 2003. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211324.
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Hooks, Benjamin Patrick. "Geodynamics of Terrane Accretion within Southern Alaska." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/HooksBP2009.pdf.
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Davies, David Rhodri. "Applying multi-resolution numerical methods to geodynamics." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54899/.
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Computational models yield inaccurate results if the underlying numerical grid fails to provide the necessary resolution to capture a simulation's important features. For the large-scale problems regularly encountered in geodynamics, inadequate grid resolution is a major concern. The majority of models involve multi-scale dynamics, being characterized by fine-scale upwelling and downwelling activity in a more passive, large-scale background flow. Such configurations, when coupled to the complex geometries involved, present a serious challenge for computational methods. Current techniques are unable to resolve localized features and, hence, such models cannot be solved efficiently. This thesis demonstrates, through a series of papers and closely-coupled appendices, how multi-resolution finite-element methods from the forefront of computational engineering can provide a means to address these issues. The problems examined achieve multi-resolution through one of two methods. In two-dimensions (2-D), automatic, unstructured mesh refinement procedures are utilized. Such methods improve the solution quality of convection dominated problems by adapting the grid automatically around regions of high solution gradient, yielding enhanced resolution of the associated flow features. Thermal and thermo-chemical validation tests illustrate that the technique is robust and highly successful, improving solution accuracy whilst increasing computational efficiency. These points are reinforced when the technique is applied to geophysical simulations of mid-ocean ridge and subduction zone magmatism. To date, successful goal-orientated/error-guided grid adaptation techniques have not been utilized within the field of geodynamics. The work included herein is therefore the first geodynamical application of such methods. In view of the existing three-dimensional (3-D) spherical mantle dynamics codes, which are built upon a quasi-uniform discretization of the sphere and closely coupled structured grid solution strategies, the unstructured techniques utilized in 2-D would throw away the regular grid and, with it, the major benefits of the current solution algorithms. Alternative avenues towards multi-resolution must therefore be sought. A non-uniform structured method that produces similar advantages to unstructured grids is introduced here, in the context of the pre-existing 3-D spherical mantle dynamics code, TERRA. The method, based upon the multigrid refinement techniques employed in the field of computational engineering, is used to refine and solve on a radially non-uniform grid. It maintains the key benefits of TERRA's current configuration, whilst also overcoming many of its limitations. Highly efficient solutions to non-uniform problems are obtained. The scheme is highly resourceful in terms RAM, meaning that one can attempt calculations that would otherwise be impractical. In addition, the solution algorithm reduces the CPU-time needed to solve a given problem. Validation tests illustrate that the approach is accurate and robust. Furthermore, by being conceptually simple and straightforward to implement, the method negates the need to reformulate large sections of code. The technique is applied to highly advanced 3-D spherical mantle convection models. Due to its resourcefulness in terms of RAM, the modified code allows one to efficiently resolve thermal boundary layers at the dynamical regime of Earth's mantle. The simulations presented are therefore at superior vigor to the highest attained, to date, in 3-D spherical geometry, achieving Rayleigh numbers of order 109. Upwelling structures are examined, focussing upon the nature of deep mantle plumes. Previous studies have shown long-lived, anchored, coherent upwelling plumes to be a feature of low to moderate vigor convection. Since more vigorous convection traditionally shows greater time-dependence, the fixity of upwellings would not logically be expected for non-layered convection at higher vigors. However, such configurations have recently been observed. With hot-spots widely-regarded as the surface expression of deep mantle plumes, it is of great importance to ascertain whether or not these conclusions are valid at the dynamical regime of Earth's mantle. Results demonstrate that at these high vigors, steady plumes do arise. However, they do not dominate the planform as in lower vigor cases: they coexist with mobile and ephemeral plumes and display ranging characteristics, which are consistent with hot-spot observations on Earth. Those plumes that do remain steady alter in intensity throughout the simulation, strengthening and weakening over time. Such behavior is caused by an irregular supply of cold material to the core-mantle boundary region, suggesting that subducting slabs are partially responsible for episodic plume magmatism on Earth. With this in mind, the influence of the upper boundary condition upon the planform of mantle convection is further examined. With the modified code, the CPU-time needed to solve a given problem is reduced and, hence, several simulations can be run efficiently, allowing a relatively rapid parameter space mapping of various upper boundary conditions. Results, in accordance with the investigations on upwelling structures, demonstrate that the surface exerts a profound control upon internal dynamics, manifesting itself not only in convective structures, but also in thermal profiles, Nusselt numbers and velocity patterns. Since the majority of geodynamical simulations incorporate a surface condition that is not at all representative of Earth, this is a worrying, yet important conclusion. By failing to address the surface appropriately, geodynamical models, regardless of their sophistication, cannot be truly applicable to Earth. In summary, the techniques developed herein, in both 2- and 3-D, are extremely practical and highly efficient, yielding significant advantages for geodynamical simulations. Indeed, they allow one to solve problems that would otherwise be unfeasible.
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Al-Attar, David. "Theoretical problems in global seismology and geodynamics." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:e700e8df-49d0-47e0-8929-cd254c5416c1.
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In Chapter 2, we consider the hydrostatic equilibrium figure of a rotating earth model with arbitrary radial density profile. We derive an exact non-linear partial differential equation describing the equilibrium figure. Perturbation theory is used to obtain approximate forms of this equation, and we show that the first-order theory is equivalent to Clairaut's equation. In Chapter 3, a method for parametrizing the possible equilibrium stress fields of a laterally heterogeneous earth model is described. In this method a solution of the equilibrium equations is first found that satisfies some desirable physical property. All other solutions can be written as the sum of this equilibrium stress field and a divergence-free stress tensor field whose boundary tractions vanish. In Chapter 4, we consider the minor vector method for the stable numerical solution of systems of linear ordinary differential equations. Results are presented for the application of the method to the calculation of seismic displacement fields in spherically symmetric, self-gravitating earth models. In Chapter 5, we present a new implementation of the direct solution method for calculating normal mode spectra in laterally heterogeneous earth models. Numerical tests are presented to demonstrate the validity and effectiveness of this method for performing large mode coupling calculations. In Chapter 6, we consider the theoretical basis for the viscoelastic normal mode method which is used in studies of seismic wave propagation, post-glacial rebound, and post-seismic deformation. We show how the time-domain solution to the viscoelastodynamic equation can be written as a normal mode sum in a rigorous manner.
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Martin, Erin Lee. "Understanding Neoproterozoic geodynamics through Hafnium isotope arrays." Thesis, Curtin University, 2020. http://hdl.handle.net/20.500.11937/80148.
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The Neoproterozoic supercontinent Rodinia assembled by the collision of a global-scale subduction girdle at the end of the Mesoproterozoic. A new subduction girdle is not established until the assembly of Gondwana some 500 Ma later, at the end of the Neoproterozoic. Thus, the global Hf isotope record suggests that the Neoproterozoic was dominated by the degree-1 condition, which facilitated Gondwana amalgamation, but it is not clear that degree-2 mantle convection facilitated the breakup of Rodinia.
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Lee, Hyongki. "Radar Altimetry Methods for Solid Earth Geodynamics Studies." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1221761881.
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Meredith, David. "2-D and 3-D computer modelling of lithosphere dynamics and sedimentary basin formation." Thesis, Keele University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288437.
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Daniel, Andrew John. "The geodynamics of spreading centre subduction in southern Chile." Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320503.
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Ransome, Ian G. D. "The geochemistry, kinematics and geodynamics of the Gannakouriep dyke swarm." Master's thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/22550.
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Bibliography: pages 106-110.The Gannakouriep dyke swarm comprises a linear swarm of north to northeast striking mafic dykes emplaced during late Proterozoic rifting in the Gariep belt. The swarm has a strike length of over 300 km crossing terrane boundaries of the Gordonia sub-province, Richtersveld igneous sub-province and 8 ushmanland sub-province of the Namaqua Mobile Province. The main axis of dyke intrusion is centred within the 2.0 Ga Richtersveld igneous sub-province where the density of dyking increases westwards across strike towards the Gariep belt, prior to disappearing within the sediment/basement contact of the para-autochthonous Port Nolloth Assemblage. An internal Rb-Sr mineral isochron, together with pyroxene K-Ar plateau and whole rock model TCHUR ages, indicate that the dyke swarm was intruded around 720 Ma. The majority of the dykes comprise subophitic relict gabbros and dolerites of alkali affinities replaced by metamorphic minerals of both greenschist and amphibolite facies. The greenstones are encountered within the NE striking eastern sector of the dyke swarm which records the original tensile stress field, whilst amphibolites are encountered in the northerly striking western sector of the swarm which has been rotated 26° anticlockwise during Pan-African (500-550 Ma) deformation in the Gariep belt. The latter age of regional metamorphism and deformation is supported by available K-Ar age data on whole rock samples and amphibole mineral separates. Integrated field relationships, continuum mechanics modelling and geochemical studies suggest that the swarm was initiated as a series of low level crustal magma chambers which subsequently gave rise to a series of dyke complexes that comprise the Gannakouriep dyke swarm. The geochemical variability between individual dyke complexes across the entire swarm is negligible; only slight differences being recorded by their high-field-strength element concentrations. The latter suggests that all dykes are genetically linked to a single mantle diapir, with only slight source characteristic heterogeneities. All dykes are ferro-tholeiites with no primitive (picritic) member being present. Geochemical trends recorded by the swarm are easily reconcilable in terms of fractionation of the phenocryst assemblage olivine, plagioclase, clinopyroxene, (ilmenite and Ti-magnetite). However an earlier phase of fractionation of essentially olivine and plagioclase at the base of the crust is suggested since constraints on the degree of partial melting (3-6%) imposed by REE patterns would derive an alkali basalt parental melt. The geodynamic relationship between the Gannakouriep dyke swarm and rifting in the Gariep belt is accounted for by a lithospheric plate model containing non-coincidental crustal and mantle weaknesses represented by late Namaquan D4n extensional faults and a mantle weakness possibly resulting from crustal thickening within the Richtersveld igneous sub-province during Namaquan tectonics.
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Kulkarni, Madhav Narayan. "A feasibility study of space VLBI for geodesy and geodynamics /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487776210796273.
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Wallis, David. "Micro-geodynamics of the Karakoram Fault Zone, Ladakh, NW Himalaya." Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/6805/.
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Microgeodynamics relates grain-scale deformation microstructures to macroscopic tectonic processes. Here the microgeodynamic approach combines optical and electron microscopy, including electron backscattered diffraction (EBSD), with field geology, geothermobarometry and microphysical modelling to study fault rocks deformed within a major continental strike-slip fault to quantify changes in fault zone structure and rheology with crustal depth. The overall thesis rational therefore is to test existing fault models against an exhumed example of a continental strike-slip fault zone, namely the central Karakoram Fault Zone (KFZ), NW India. This approach establishes changes in deformation processes with depth in the upper- to mid-crust and suggests that a range of fault weakening mechanisms have reduced fault rock shear strengths, typified by friction coefficients of 0.3-0.4. Metamorphic petrology and geothermobarometry are used to place the KFZ in the context of regional tectono-metamorphic evolution. It is shown using diagnostic microstructures and pressure-temperature-time paths that the fault initiated after peak metamorphism (677-736°C, 875-1059 MPa) and subsequent migmatisation (688±44°C, 522±91 MPa) and leucogranite emplacement (448±100 MPa). Retrograde phyllonites formed during later strike-slip deformation are investigated in detail using EBSD, geothermometry and microphysical modelling. The phyllonites formed at 351±34°C and had low shear strength (<30 MPa) during frictional-viscous flow. EBSD is also used to derive a novel strain proxy based on quartz crystal preferred orientation intensity. Application of this method distinguishes deformation distributions in transects across the KFZ. Deformation intensity varies from <0.2 in essentially undeformed domains to 1.6 within shear zone strands formed at 500-550°C and c. 15 km depth. Evaluation of the history of the KFZ suggests that whilst it plays a relatively minor role in accommodating India-Asia collision, it can nevertheless be used as an analogue for major continental strike-slip fault zone structure.
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Bergantz, George W. "Double-diffusive boundary layer convection in a porous medium : implications for fractionation in magma chambers." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/26030.
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Ravine, Michael A. "Investigations into aspects of mantle viscosity and dynamics /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9823702.
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Yeo, Lune. "Evaluating large-scale paleogeographic datasets and their responses to geodynamic processes." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/13294.
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Earth’s topographic response to the effect of mantle flow on the surface is still not fully understood. While accurate global datasets of topography through geologic time are not currently available, pale- ogeographic reconstructions illustrate the evolution of topographically-dependent environments. This thesis examines regional-global paleogeographic responses to topographic trends driven by mantle flow induced by sunken lithospheric slabs. Global paleogeographic maps are amalgamations of older, smaller regional-local studies and original data locations are not traceable. Here, we evaluate extracted Cretaceous and Cenozoic global paleoshorelines from two independent paleogeographic datasets. We find high consistency with the fossil record on a global scale for both datasets. In continental interiors, we predict the drivers of major flooding events around the world during the Cretaceous and Cenozoic by comparing trends of flooding, modelled dynamic topography and eustatic sea level. We find that eustasy and dynamic topography are often contemporaneous drivers of regional flooding, with some exceptions (e.g. flooding regression in mid-Cretaceous Australia corresponds to dynamic topography instead of eustasy). In Early-mid Cretaceous Australia, we compare flooding patterns, backstripped well subsidence and modelled slab-driven dynamic topography trends from three different model runs, which suggest that lower viscosity in the asthenosphere produces modelled dynamic topography trends that are more consistent with flooding and backstripped subsidence trends for Cretaceous Australia. The northern extents of mid-Cretaceous flooding regression in the Eromanga- Surat basins may need to be revised with respect to well subsidence profiles and marine fossil distributions. The Early Cretaceous subduction zone may need to be relocated west along the eastern Australian margin in our plate model.
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Flament, Nicolas. "Secular cooling of the solid Earth, emergence of the continents, and evolution of Earth's external envelopes." Thesis, The University of Sydney, 2010. http://hdl.handle.net/2123/6334.
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The secular cooling of the mantle and of the continental lithosphere trigger an increase in the area of emerged land. The corollary increase in weathering and erosion processes has major consequences for the evolution of Earth's external envelopes. We developed a physical model to evaluate the area of emerged land as a function of mantle temperature, continental area, and of the distribution of continental elevations. Our numerical results show that less than 15% of Earth's surface consisted of emerged land by the end of the Archaean. This is consistent with many geological and geochemical observations. To estimate the secular cooling of the continental lithosphere, we combined thermo-mechanical models with fi eld observations. Our results, constrained by geological data, suggest that the Moho temperature has decreased by ~ 200ºC over 2.7 Ga in the Pilbara Craton. To evaluate the eff ect of continental growth on the evolution of the area of emerged land, we developed a model based on published thermal evolution models. Our results suggest that the area of emerged land was less than 5% of Earth's surface in the Archaean, and that it does not depend on crustal growth. This allows to reconcile the evolution of oceanic 87Sr/86Sr with early crustal growth models. Continents are enriched in phosphorus, which is essential to the biosphere. The emergence of the continents would thus have triggered an increase in the production of oxygen by photosynthetic micro-organisms, possibly contributing to the oxidation of the atmosphere 2.4 Ga ago.
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Flament, Nicolas. "Secular cooling of the solid Earth, emergence of the continents, and evolution of Earth's external envelopes." University of Sydney, 2010. http://hdl.handle.net/2123/6334.
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Doctor of Philosphy (Cotutelle)The secular cooling of the mantle and of the continental lithosphere trigger an increase in the area of emerged land. The corollary increase in weathering and erosion processes has major consequences for the evolution of Earth's external envelopes. We developed a physical model to evaluate the area of emerged land as a function of mantle temperature, continental area, and of the distribution of continental elevations. Our numerical results show that less than 15% of Earth's surface consisted of emerged land by the end of the Archaean. This is consistent with many geological and geochemical observations. To estimate the secular cooling of the continental lithosphere, we combined thermo-mechanical models with fi eld observations. Our results, constrained by geological data, suggest that the Moho temperature has decreased by ~ 200ºC over 2.7 Ga in the Pilbara Craton. To evaluate the eff ect of continental growth on the evolution of the area of emerged land, we developed a model based on published thermal evolution models. Our results suggest that the area of emerged land was less than 5% of Earth's surface in the Archaean, and that it does not depend on crustal growth. This allows to reconcile the evolution of oceanic 87Sr/86Sr with early crustal growth models. Continents are enriched in phosphorus, which is essential to the biosphere. The emergence of the continents would thus have triggered an increase in the production of oxygen by photosynthetic micro-organisms, possibly contributing to the oxidation of the atmosphere 2.4 Ga ago.
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Grund, Michael [Verfasser]. "Exploring geodynamics at different depths with shear wave splitting / Michael Grund." Karlsruhe : KIT-Bibliothek, 2019. http://d-nb.info/117996392X/34.
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Poli, Lucio Colin. "Mid-crustal geodynamics of the southern central zone, Damara Orogen, Namibia." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/15573.
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Two areas of well exposed mid-crustal structures in the axial zone of the Pan-African Damaran orogenic belt show that basement has formed domes which have amoeboid forms on the scale of tens of km with steep sided overturned non-planar, non- cylindrical geometry. These are surrounded by open to tight synclinal cover envelopes that converge at depressions between the domes. The domes are found in association with a strong regional WSW moderately plunging lineation. Strain analysis demonstrates that domes have formed in a moderately plunging constrictional field. Structural features which normally indicate polyphase evolution such as mesoscale fold interference patterns are rare and inconsistent. Regional structural form, described morphogically by cylindrical domains, is defined by one fabric S0/S1. Secondary fabric trajectories and mesoscale fold oreintations are controlled by domain scale structure and not regional deformation trends. Dome formation is thus interpreted as being the result of a simultaneous flow and buckling episode within the middle crust. Deformation was extremely ductile. P-T estimates from thermobarometry with Grt-Bt, Grt-Crd-Bt-Sil assemblages indicate that peak metamorphic conditions during deformation were approximately 3.5kbar and 650°C in the cover envelopes and 7kbar 791°C in the basement domes, approaching the amphibolite-granulite transition. Interactive transpressional collision between three cratons during the latest Neoproterozoic-early Paleozoic: namely the Kalahari, Congo and Rio de la Plata caused constriction and extrusion in the Central Zone. The metamorphic gap between basement and cover occurred when the distance between regional isotherms was reduced by thinning at the basement-cover interface. Higher temperatures where preserved at dome cores. At the cooler margins of the Damara Belt thrust tectonics occurred, albeit obliquely with sinistral transpression. After dome formation granite intruded many domal structures.
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Perry-Houts, Jonathan. "Geodynamic Origin of the Columbia River Flood Basalts." Thesis, University of Oregon, 2019. http://hdl.handle.net/1794/24526.
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Tertiary history of the Pacific Northwest is closely tied to that of the Columbia River Flood Basalt (CRB) events. The region is, geologically, one of the least well understood parts of the continental United States.
Throughout the Neogene, the Columbia Basin and surrounding terrains appear to have been shaped not by horizontal tectonic forces, but by deep dynamic forcing, driving apparent “vertical tectonics.” This class of phenomena appears to be at odds with the traditional tenets of plate tectonics, and yet may prove to be ubiquitous geologic processes worldwide. Many of the processes described here are
unique to volcanically-active regions, such as those affected by CRB eruptions and deposition.
In the following chapters I will discuss several physical mechanisms by which lithosphere can deform in the absence of horizontal tectonic stress. These include analyses of the mechanisms associated with metamorphic densification, rheologic transformation owing to magmatic intrusions, and the dynamics of lithospheric delamination.
All code and documentation to reproduce the results presented here can be found in the supplemental files included with this dissertation. Appendices A and B document the purpose, usage, and functionality of each supplementary file.
This dissertation includes previously published and unpublished coauthored material.
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Polat, Ali. "Geodynamics of the late Archean Wawa Subprovince Greenstone Belts, Superior Province, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0014/NQ32797.pdf.
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Pedrosa, Adriana Albuquerque. "Geodynamics and morphogenesis dunes wind in broken canoe municipality, Aracati, Ceara, Brazil." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16971.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorThis thesis presents an analysis of geodynamic and morphogenesis of the dune field in the Canoa Quebrada region located in the municipality of Aracati inserted in the state of CearÃ. It covers the area formed by fluvial-marine plain, the strip of beach and dune field located on the right bank of the mouth of the river Jaguaribe. The estimated time frame corresponds to the dynamic analysis of the dune field based on migration rates from 1988 to 2013. The objectives of this study are to analyze the environmental dynamics of the mobile dune field towards the mangrove ecosystem located at the mouth of the river Jaguaribe. Associated with the methodological approach, we used a set of techniques necessary for the completion of this research. From then analyzed through GIS aerial photographs of the 80 on the scale of 1: 25,000 and 2004 Quickbird the years of satellite images, 2010 and 2013 associated with the study of wind dynamics based on the variation of records their migration rates. In the study area, we find the moving dunes of the longitudinal type, small occurrence barcanoids, expressive occurrence and prevalence of sand sheets. The vegetation point of view, semi-fixed dunes were identified in contact with the mangrove ecosystem. These dunes can be classified as semi-fixed shapeless. There is no occurrence of fixed dunes or cemented dunes in the region. As for dune generations in Canoa Quebrada, dominates the generation D1, characterized by the occurrence of current dunes, furniture. In contact with the mangrove ecosystem, the semi-fixed dunes combine with the previous generation of dunes to the current, the current sub-type, defining the existence of D2 generation dunes. The average migration of the dune field during that period of 40 years was 7m / year. In the years 2010-2013 virtually no migration occurred, but the dunes continue to migrate towards the mangrove ecosystem.
Esta Tese apresenta uma anÃlise da geodinÃmica e morfogÃnese do campo de dunas na regiÃo de Canoa Quebrada localizada no municÃpio do Aracati inserido no estado do CearÃ. Abrange a Ãrea formada pela planÃcie fluvio-marinha, a faixa de praia e o campo de dunas localizados na margem direita da foz do rio Jaguaribe. O recorte temporal avaliado corresponde à anÃlise da dinÃmica do campo de dunas com base nas taxas de migraÃÃo no perÃodo de 1988 a 2013. Os objetivos dessa pesquisa foram analisar a dinÃmica ambiental do campo de dunas mÃveis em direÃÃo ao ecossistema manguezal localizado na foz do rio Jaguaribe. Associado à abordagem metodolÃgica, utilizou-se um conjunto de tÃcnicas necessÃrias à realizaÃÃo da presente pesquisa. A partir de entÃo, analisou-se atravÃs do geoprocessamento de fotografias aÃreas da dÃcada de 80 na escala de 1:25.000 e imagens de satÃlites Quickbird dos anos de 2004, 2010 e 2013 associados ao estudo da dinÃmica eÃlica com base nos registros da variaÃÃo de suas taxas de migraÃÃo. Na Ãrea de estudo, encontramos dunas mÃveis do tipo longitudinais, de pequena ocorrÃncia, barcanÃides, de expressiva ocorrÃncia e a predominÃncia dos lenÃÃis de areias. Do ponto de vista de cobertura vegetal, foram identificadas dunas semi-fixas no contato com o ecossistema manguezal. Essas dunas podem ser classificadas como semi- fixas sem forma definida. NÃo hà ocorrÃncia de dunas fixas ou de dunas cimentadas na regiÃo. Quanto Ãs geraÃÃes dunares, em Canoa Quebrada, domina a geraÃÃo D1, caracterizada pela ocorrÃncia de dunas atuais, mÃveis. No contato com o ecossistema manguezal, as dunas semi-fixas se combinam com a geraÃÃo de dunas anteriores Ãs atuais, do tipo sub-atuais, definindo a existÃncia de dunas de geraÃÃo D2. A taxa mÃdia de migraÃÃo no campo de dunas durante todo esse perÃodo de 40 anos foi de 7m/ano. Nos anos de 2010 a 2013 praticamente nÃo ocorreu migraÃÃo, mas as dunas continuam migrando em direÃÃo ao ecossistema manguezal.
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Rowan, Christopher James. "Neogene paleomagnetism and geodynamics of the Hikurangi margin, East Coast, New Zealand." Thesis, University of Southampton, 2006. https://eprints.soton.ac.uk/41330/.
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Vertical-axis rotations are an important component of Neogene deformation in the New Zealand plate boundary region, and potentially offer fundamental insights into the rheology of continental crust. Extensive paleomagnetic sampling along the Hikurangi margin, on the East Coast of the North Island, has provided new insights into the patterns, rates and timings of tectonic rotation, and also an improved understanding of the magnetic signature of New Zealand Cenozoic mudstones. Rigorous field tests reveal numerous late remagnetizations, which haveoften formed several million years after deposition and can be irregularly distributed within an outcrop. Scanning electron microscopy and rock magnetic analyses indicate that the remanence carrier is predominantly the ferrimagnetic iron sulphide, greigite, which is present as a mixed population of single domain and superparamagnetic grains that are characteristic of arrested authigenic growth. Strong viscous overprints are the result of later, usually recent, oxidation of these sulphides. The recognition of late-forming magnetizations leads to a completely new view of the Neogene tectonic evolution of the Hikurangi margin, with no tectonic rotations being evident prior to 8–10 Ma; coherent rotation of most of the Hikurangi margin since that time refutes the existence of the independently rotating ‘domains’ that were inferred from earlier paleomagnetic data. This pattern is more consistent with the short-term velocity field, and allows all Neogene rotation to be more simply explained as a large-scale response to realignment of the subducting Pacific plate. Tectonic rotations have been accommodated by a variety of structures since 10 Ma; in the Late Miocene and Pliocene, rates of tectonic rotation were 3–4 times faster than presently observed and possibly involved a much larger region, before initiation of the North Island Dextral Fault Belt and the Taupo Volcanic Zone at 1-2 Ma instigated the current tectonic regime. Collision of the Hikurangi Plateau in the Late Miocene is interpreted to have caused both the initiation of tectonic rotation, and the widespread remagnetization of sediments, making it a key event in the Neogene evolution of the plate boundary region.
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Walpole, Jack. "Constraining mineralogy and geodynamics at the base of the mantle using seismic anistropy." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683386.
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Many new observations of seismic anisotropy in the upper and lower boundary layers of the mantle are presented. These observations (from shear-wave splitting on SKS, receiver corrected S, and receiver/source corrected ScS phases) constrain the mineralogy and geodynamics in these regions, which are crucially important to mantle convection. The main target of this thesis is the lower boundary layer: the lowermost mantle; where the new (ScS) dataset greatly expands on the pre-existing coverage to reveal a global dominance of SH fast anisotropy with strength ~1.4 %. Interesting deviations are detected inside the Pacific large low shear velocity province where SV is fast; and in the 'slab graveyard' region beneath Eurasia where the angle of fast wave polarisation shows coherent regional variations in dip suggesting the presence of large-scale (~1000 km) structural features. A model of flow in the lowermost mantle is tested with the hypothesis that the anisotropy is caused by the lattice preferred orientation of MgSi03 post-perovskite. It is demonstrated that the accuracy of ray theory is inadequate to test general models of anisotropy in the lowermost mantle and that a full waveform finite frequency method is required. Finite frequency waveform results do not match the observations for three candidate post-perovskite plastic deformation models (dislocation glide on (001), (010), and (100)/{11O}). Therefore either the flow model is wrong or anisotropy in the lowermost mantle is not caused by dislocation glide deformation in post-perovskite. Anisotropy in the upper mantle causes on average 0.8 s of splitting beneath seismic stations (determined from the SKS dataset). The fast wave tends to be polarised in line with the direction of absolute plate motion in regions disturbed by orogeny in the last 540 Ma. This suggests that orogenies deform the mantle. Beneath subduction zones, anisotropy causes an average 1.3 s of splitting in events shallower than 300 km (from the S dataset). The fast direction tends to be aligned with the strike of the slab (trench parallel splitting); notable exceptions are identified in South America, the Izu-Bonin arc, a segment of the Sunda arc, and at the Hokkaido corner. Interestingly, in each of these regions the trench is migrating forward in the direction of the subducting plate's motion. With the exception of the Mariana arc, subduction zones experiencing trench roll-back all display trench parallel shear wave splitting. This suggests that trench parallel splitting is caused by mantle deformation associated with trench roll-back. Events deeper than 300 km split by an average 0.9 s; this remains true of events deeper than 520 km. The lack of depth dependence on splitting beyond 300 km hints that anisotropy is confined to the slab or is located in a region deeper than ~660 km.
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Yuan, Huaiyu. "Western United States lithosphere-asthenosphere interaction Modern day small scale convection, plume and ancient lithospheric heterogeneity /." Laramie, Wyo. : University of Wyoming, 2007. http://proquest.umi.com/pqdweb?did=1400957251&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Stokes, Martin. "Plio-Pleistocene drainage evolution of the Vera Basin, SE Spain." Thesis, University of Plymouth, 1997. http://hdl.handle.net/10026.1/1289.
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The Vera Basin is used as a case study to examine the structural evolution and sedimentary response of a basin undergoing uplift and inversion during the Plio-Pleistocene. Particular emphasis is placed on the drainage evolution during that period. Located within the Internal zone of the Betic Cordilleras, the Vera Basin is defined within a large left-lateral shear zone and has evolved as a reponse to isostatic uplift from nappe emplacement during the Oligocene, and by regional compressive tectonics. Since basin formation during the Seravallian, sedimentary fill has been dominantly marine. During the Plio-Pleistocene a switch from marine to continental conditions occurred. These sediments (Cuevas, Espiritu Santo and Salmerbn Formations) represent the final stages of basin fill and form the focus of this study. The Cuevas Formation represents an early Pliocene marine transgression within the Vera Basin. Early sedimentation mulled a pronounced submarine topography produced by a rapid late Miocene fall in sealevel. A broad, shallow shelf platform area existed which opened out to the Pliocene Mediterranean Sea towards the east. Along the northern and western basin margins, wave dominated shorelines were formed. Structural activity was confined to low amounts of basin subsidence and limited left lateral strike-slip movement along the Palomares Fault Zone. The Espiritu Santo Formation marks a major palaeogeographic reorganisation and the final marine phases of the Vera Basin during the mid to late Pliocene. Unsteady strike-slip movement along the Palomares fault zone on the eastern basin margin partially enclosed the Vera Basin by northwards movement of a structurally detached landmass. Gilbert-type fan-delta bodies prograded westwards from the landmass (Sierra Almagrera), infilling the central region of the basin. Early fan-delta sediments were reworked into shoreline areas along the western and northern basin margins. Western margin shorelines retreated northwards as a response to partial enclosure and a gradual lowering of sea-level. Late stages of the Espiritu Santo Formation, saw a fan-delta body prograde from the northern basin margins. Interaction between the basinal and marginal fan-delta bodies enclosed the northern region of the Vera Basin. A swamp/mangrove environment developed within the enclosed northern basin area suggesting a humid, sub-tropical climate. Continental conditions were established during Salmerön Formation times in the late Pliocene. Along the western and northern basin margins, the retreating Pliocene shorelines provided a topography onto which the primary consequent drainage network developed. Three separate drainage systems can be identified on the basis of clast assemblages, palaeocurrents, depositional style and morphological expression. Early deposition was characterised by the progradation of alluvial fans of two drainage systems (Cuevas & Jauro), sourced from the northern and western basin margins. Distal areas of the northern fan system intercalated with an evaporitic playa lake. A third drainage system in the northwest of the basin (Salmerbn) developed within a topographic low between the two fan systems. An increase in structural activity towards the end of the Salmerbn Formation was characterised by a basin wide phase of north-south compression. Uplift and extensional faulting lead to abandonment of the primary drainage network. Fan entrenchment and minor rerouting of sediment supplies marked the establishment of a new secondary consequent drainage network during the Pleistocene. The Pleistocene drainage network records the progressive dissection of the Vera Basin as a response to ongoing regional epeirogenic uplift. During this post-inversion phase the Rios Antas, Almanzora and Aguas developed respectively along the western, northern and southern basin margins as- a series of braided streams. Distal, coastal areas of this drainage network are recorded by a series of Pleistocene shoreline sequences which developed as a response to fluctuating sea-level during the Pleistocene glacial and interglacial periods. Early Pleistocene proximal parts of the drainage network are well preserved. Distal parts of the Pleistocene fluvial system display limited evidence for interaction between the drainage network and shoreline sequences. This lack of preservation relates to the high energy, wave dominated depositional setting of the Pleistocene shoreline areas which reworked fluvial sediment inputs into the shoreline environment. The Plio-Pleistocene evolution of the Vera Basin, and in particular the development of the fluvial during system this period has been highly complex. Despite the importance of sea-level and climatic controls, tectonic activity during this period of basin inversion has been the dominant control on the positioning of the drainage networks, depositional styles and sediment supply.
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Walker, Christian Bryan. "The tectonothermal evolution of the high himalayas in the Suru valley, NW Zanskar, with constraints from metamorphic modelling." Thesis, University of Oxford, 1999. http://ora.ox.ac.uk/objects/uuid:bac5b462-854e-4741-a787-ef3fe23647d0.
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This thesis attempts to construct an integrated model for the tectonothermal evolution of the Suru valley region of the High Himalayan Crystalline unit of north-west India, and combines detailed field mapping, petrographic and microstructural analysis, thermobarometric techniques and metamorphic modelling. This work confirms that the metasedimentary lithologies of the Suru valley correspond to the Palaeozoic-Mesozoic Tethyan shelf sediments found in Kashmir and Zanskar and that the meta-igneous bodies correlate with Permian rift-related igneous units. This demonstrates that all the metamorphism in the Suru valley is Himalayan in age. Subsequent to India-Asia collision at ~54 Ma the units of the Suru valley underwent a polyphase deformational and metamorphic history. The large scale structure of the area is that of kilometre-scale, SWvergent recumbent folds that are domed by a later structure, the Suru Dome. Barrovian metamorphism resulting from collision and burial reached a maximum of kyanite grade, and is believed to be syn- to post-kinematic with respect to the formation of the large folds. Thermobarometric analysis indicates that peak conditions relating to this Barrovian event were of the order of 9.5-10.5 kbar and 620-650 0C. A later metamorphic event associated with doming throughout the Zanskar Himalaya and crustal anatexis in the core of the High Himalaya caused re-equilibration of deeper Suru Dome rocks to conditions of 8.7-9.7 kbar and 630-640 0C. Metamorphic modelling, involving phase diagram construction and P-T path determination using Gibbs method calculations, suggests that metamorphic garnets grew under conditions of burial and heating. Rapid exhumation of the High Himalayan Crystallines on the Main Central Thrust and the Zanskar Shear Zone occurred shortly after peak metamorphism. The results suggest that phase diagram construction and P-T path calculation should be used in conjunction in order to confidently model metamorphic rocks.
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Richards, Frederick David. "Global analysis of predicted and observed dynamic topography." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/284159.
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While the bulk of topography on Earth is generated and maintained by variations in the thickness and density of crust and lithosphere, a significant time-variable contribution is expected as a result of convective flow in the underlying mantle. For over three decades, this dynamic topography has been calculated numerically from inferred density structure and radial viscosity profiles. Resulting models predict ±2 km of long wavelength (i.e., ~ 20,000 km) dynamic topography with minor contributions at wavelengths shorter than ~ 5,000 km. Recently, observational studies have revealed that, at the longest wavelengths, dynamic topography variation is ~ 30% that predicted, with ±1 km amplitudes recovered at shorter wavelengths. Here, the existing database of water-loaded basement depths is streamlined, revised and augmented. By fitting increasingly sophisticated thermal models to a combined database of these oceanic basement depths and corrected heat flow measurements, the average thermal structure of oceanic lithosphere is constrained. Significantly, optimal models are consistent with invariable geochemical and seismological constraints whilst yielding similar values of mantle potential temperature and plate thickness, irrespective of whether heat flow, subsidence or both are fit. After recalculating residual depth anomalies relative to optimal age-depth subsidence and combining them with continental constraints from gravity anomalies, a global spherical harmonic representation is generated. Although, long wavelength dynamic topography increases by ~ 40% in the revised observation-based model, spectral analysis confirms that a fundamental discrepancy between observations and predictions remains. Significantly, residual depth anomalies reveal a ~4,000 km-scale eastward tilt across the Indian Peninsula. This asymmetry extends onshore from the high-elevation Western Ghats in the west to the Krishna-Godavari floodplains in the east. Calibrated inverse modelling of drainage networks suggest that the tilt of the peninsula grew principally in Neogene times with vertical motions linked to asthenospheric temperature anomalies. Uplift rates of up to 0.1 mm a⁻¹ place important constraints on the spatio-temporal evolution of dynamic topography and suggest that rates of transient vertical motion exceed those predicted by many modelling studies. Most numerical models excise the upper ~ 300 km of Earth's mantle and are unable to reconstruct the wavelength and rate of uplift observed across Peninsular India. By contrast, through conversion of upper mantle shear wave velocities to density using a calibrated anelastic parameterisation, it is shown that shorter wavelength (i.e., ≤ 5,000 km) dynamic topography, can mostly be explained by ±150°C asthenospheric temperature anomalies. Inclusion of anelastically corrected density structure in whole-mantle instantaneous flow models also serves to reduce discrepancy between predictions and observations of dynamic topography at long wavelengths. Residual mismatch between observations and predictions is further improved if the basal 300-600 km of large low shear wave velocity regions in the deep mantle are geochemically distinct and negatively buoyant. Finally, inverse modelling of geoid, dynamic topography, gravity and core-mantle boundary topography observations using adapted density structure suggests that geodynamic constraints can be acceptably fit using plausible radial viscosity profiles, contradicting a long-standing assertion that modest long wavelength dynamic topography is incompatible with geoid observations.
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Booth, Sophie Catherine. "Causes of subsidence within retroarc foreland basins." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367069.
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Tarlow, Scott. "Three Dimensional Modeling of mantle melt underneath Lau's Back-Arc spreading center and Tofua Volcanic Arc." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/theses/1482.
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Valu Fa and Eastern Lau `s (two regions along Lau's back-arc spreading center) observed axial morphology suggest that Valu Fa is more magmatically robust than Eastern Lau despite Eastern Lau's spreading rate nearly doubling Valu Fa's. Early geochemical [Pearce et al., 1994] and geophysical [Martinez and Taylor, 2002] studies predict a gradational decrease in melting moving north from Valu Fa to Eastern Lau, but more recent geochemical and seismic observations ([Escrig, .et al 2009]; [Dunn and Martinez, 2011]; [Dunn et al., 2011]) show a sharper stepwise decrease in melting as the spreading center's ridge axis sweeps away from the Tofua Volcanic-Arc. As the ridge sweeps away from the volcanic-arc, the influence of the slab hydrated mantle in the melting structure of the ridge decreases. Furthermore, Eastern Lau produces a thinner crust than expected for a robust spreading center. 2-D numerical studies [Harmon and Blackmon, 2010] show a gradational decrease in melting from Valu Fa to Eastern Lau but with no corresponding thinning of Eastern Lau's crust. To understand the melting dynamics underneath Lau's back-arc spreading center and the Tofua Volcanic-Arc implementing the effects of 3-D mantle flow and slab hydration appears to be required. To explain the observed geochemical and seismic observations, three 3-D numerical were performed, using a community developed mantle convection solver (CitcomS). The first model shows that observed geometric and surface kinematic boundary conditions cause a steep gradational increase in relative melting area (anhydrous) moving northward with increasing spreading rate along the ridge axis from Valu Fa to Eastern Lau caused by a northwestern along axis mantle flow. A peak in the relative melting area appears particularly close to Eastern Lau where crust is thinnest. These predictions run in opposition to the observations. The second model shows including a viscosity reduction in the mantle wedge due to slab hydration causes a more subdued relative melting increase with spreading rate and "saddle" shaped decrease in relative melting area north of 20.9°S. This saddle shaped melting structure is caused by a reversal in along axis flow towards the southeast, which takes hot mantle from Eastern Lau and transports it underneath Valu Fa accounting for the anomalously thin crust observed at Eastern Lau. Finally, introducing a hydrated solidus increases the melt production under Valu Fau and causes a stepwise decrease in melt production at Eastern Lau due to its decreased proximity to the slab-hydrated region, consistent with the observed geochemical and seismic studies.
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Richter, Andreas. "Geodätische Arbeiten im Gebiet des subglazialen Lake Vostok." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-170445.
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Richter, Andreas. "Geodätische Arbeiten im Gebiet des subglazialen Lake Vostok." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A28739.
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Painter, Clayton S. "Sequence stratigraphy, geodynamics, and detrital geothermochronology of Cretaceous foreland basin deposits, western interior U.S.A." Thesis, The University of Arizona, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3600290.
Full textAbstract:
Three studies on Cordilleran foreland basin deposits in the western U.S.A. constitute this dissertation. These studies differ in scale, time and discipline. The first two studies include basin analysis, flexural modeling and detailed stratigraphic analysis of Upper Cretaceous depocenters and strata in the western U.S.A. The third study consists of detrital zircon U-Pb analysis (DZ U-Pb) and thermochronology, both zircon (U-Th)/He and apatite fission track (AFT), of Upper Jurassic to Upper Cretaceous foreland-basin conglomerates and sandstones. Five electronic supplementary files are a part of this dissertation and are available online; these include 3 raw data files (Appendix_A_raw_isopach_data.txt, Appendix_C_DZ_Data.xls, Appendix_C_U-Pb_apatite.xls), 1 oversized stratigraphic cross section (Appendix_B_figure_5.pdf), and 1 figure containing apatite U-Pb concordia plots (Appendix_C_Concordia.pdf).
Appendix A is a combination of detailed isopach maps of the Upper Cretaceous Western Interior, flexural modeling and a comparison to dynamic subsidence models as applied to the region. Using these new isopach maps and modeling, I place the previously recognized but poorly constrained shift from flexural to non-flexural subsidence at 81 Ma.
Appendix B is a detailed stratigraphic study of the Upper Cretaceous, (Campanian, ~76 Ma) Sego Sandstone Member of the Mesaverde Group in northwestern Colorado, an area where little research has been done on this formation.
Appendix C is a geo-thermochronologic study to measure the lag time of Upper Jurassic to Upper Cretaceous conglomerates and sandstones in the Cordilleran foreland basin. The maximum depositional ages using DZ U-Pb match existing biostratigraphic age controls. AFT is an effective thermochronometer for Lower to Upper Cretaceous foreland stratigraphy and indicates that source material was exhumed from >4–5 km depth in the Cordilleran orogenic belt between 118 and 66 Ma, and zircon (U-Th)/He suggests that it was exhumed from <8–9 km depth. Apatite U-Pb analyses indicate that volcanic contamination is a significant issue, without which, one cannot exclude the possibility that the youngest detrital AFT population is contaminated with significant amounts of volcanogenic apatite and does not represent source exhumation. AFT lag times are <5 Myr with relatively steady-state to slightly increasing exhumation rates. Lag time measurements indicate exhumation rates of ~0.9->>1 km/Myr.
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Zahirovic, Sabin. "Post-Pangea global plate kinematics and geodynamic implications for Southeast Asia." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/13327.
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Modern plate reconstructions, with evolving plate boundaries that document the breakup of Pangea hold vital clues for the factors affecting plate motions. Previous studies have evaluated the present-day plate arrangements and velocities, and therefore cannot capture the inherent plate behaviour over deep geological time. A handful of studies have used plate reconstructions to alleviate these temporal shortcomings, but have been limited by the small number of plate reconstruction timesteps, leading to conflicting suggestions that continents may both inhibit or promote fast plate motions. This thesis demonstrates that increasing portions of continental plate area significantly reduces plate velocities when using a post-Pangea plate reconstruction framework. However, plates with large continents exhibit short-lived (~5-10 Myr) but high-amplitude anomalous accelerations that are often related to plume head arrivals. The breakup of Pangea opened the vast Atlantic, Indian and Southern Oceans at the expense of the equatorial oceanic gateway that linked the Tethys and (proto-) Pacific. Refined reconstructions of this lost oceanic gateway, in the absence of preserved oceanic crust, required a synthesis of geological data from the continents that travelled on these now-subducted plates. By coupling the refined plate reconstructions to numerical mantle flow simulations, this thesis demonstrates that the short-lived (~10-15 Myr) subduction hiatus from the accretion of continental blocks at ~80 Ma along southern Sundaland resulted in ~200 m of dynamic uplift of the continental promontory, which was likely responsible for the enigmatic Late Cretaceous to Paleocene regional unconformity. The approaches presented in this thesis highlight the need for data-driven global plate reconstructions, coupled to geodynamic simulations of mantle flow in a global spherical mantle shell, to study both the global plate-mantle system but also address regional geological enigmas.
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Petrlík, Karel. "Opakovaná GPS měření na polygonu Tetčice." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-390235.
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This diploma thesis deals with epoch GNSS measurement by static method at Tetčice polygon. The main purpose is to confirm the geological activity of the Earth's surface on the territory of the village, caused by a tectonic fault. As part of the thesis, the fourth phase of observation was carried out in June 2016 to detect horizontal shifts on four concrete pillars with depth stabilization and forced centering equipment. Results are velocity vector maps obtained by processing the measured data from all the measurement phases that have been performed so far. The thesis also contains the theoretical basis of geological conditions in the area and a description of technology of global navigation satellite systems.
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Tetley, Michael Grant. "Constraining Earth’s plate tectonic evolution through data mining and knowledge discovery." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18737.
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Global reconstructions are reasonably well understood to ~200 Ma. However, two first-order uncertainties remain unresolved in their development: firstly, the critical dependency on a self-consistent global reference frame; and secondly, the fundamental difficulty in objectively predicting the location and type of tectonic paleo-boundaries. In this thesis I present three new studies directly addressing these fundamental geoscientific questions. Through the joint evaluation of global seafloor hotspot track observations (for times younger than 80 Ma), first-order geodynamic estimates of global net lithospheric rotation (NLR), and parameter estimation for paleo-trench migration (TM) behaviours, the first chapter presents a suite of new geodynamically consistent, data-optimised global absolute reference frames spanning from 220 Ma through to present-day. In the second chapter, using an updated paleomagnetic pole compilation to contain age uncertainties, I identify the optimal APWP pole configuration for 16 major cratonic blocks minimising both plate velocity and velocity gradients characteristic of eccentric changes in predicted plate motions, producing a new global reference frame for the Phanerozoic consistent with physical geodynamic principles. In the final chapter of my thesis I identify paleo-tectonic environments on Earth through a machine learning approach using global geochemical data, deriving a set of first-order discriminatory tectonic environment models for mid-ocean ridge (MOR), subduction (ARC), and oceanic hotspot (OIB) environments. Key discriminatory geochemical attributes unique to each first-order tectonic environment were identified, enabling a data-rich identification of samples of unknown affinity. Applying these models to Neoproterozoic data, 56 first-order tectonic paleo-boundaries associated with Rodinia supercontinent amalgamation and dispersal were identified and evaluated against published Neoproterozoic reconstructions.
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Rülke, Axel. "Zur Realisierung eines terrestrischen Referenzsystems in globalen und regionalen GPS-Netzen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-24543.
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Die geodätischen Beobachtungsverfahren leisten auf verschiedene Weise Beiträge zur Erforschung des Systems Erde: Einerseits beobachten sie die rezenten Prozesse und ihre zeitlichen Variationen direkt, andererseit liefert sie die Grundlage für die konsistente Betrachtung aller Einflüsse in einem einheitlichen geometrischen und gravimetrischen Bezug. Das Projekt des Global Geodetic Observing System (GGOS) der Internationalen Assoziation für Geodäsie (IAG) soll die Voraussetzungen zur Vereinigung der verschiedenen geodätischen Beobachtungsverfahren, Modelle und Auswertemethoden mit dem Ziel schaffen, mit einem konsistenten Satz geodätischer Parameter ein hochgenaues Monitoring des Systems Erde zu ermöglichen. Die Realisierung geodätischer Bezugssysteme mit höchsten Genauigkeitsansprüchen ist in diesem Kontext eine zentrale Aufgabe des GGOS und Thema der vorliegenden Arbeit. In der derzeit üblichen Darstellung umfasst eine Realisierung des Terrestrischen Referenzsystems (TRS) Stationspositionen zu einer spezifischen Epoche und ihre linearen Änderungen mit der Zeit. In diesem Konzept führen alle nichtlinearen Stationsbewegungen zu residualen Abweichungen, die geowissenschaftlich interpretiert werden können. Der natürliche Ursprung eines globalen TRS, so auch des International Terrestrial Reference System (ITRS), liegt im Massezentrum des Systems Erde (CM). Mit Hilfe dynamischer Satellitenverfahren, wie GPS, lässt sich dieser Ursprung aus geodätischen Beobachtungen realisieren. In einem konsistenten Ausgleichungsansatz werden Satellitenbahnen, Stationspositionen und die in Kugelflächenfunktionen niedrigen Grades modellierte Auflastdeformation gemeinsam geschätzt. Die Grundlage der Realisierung des ITRS bilden in einem gemeinsamen Projekt der TU Dresden, der TU München und des GFZ Potsdam reprozessierte Beobachtungen eines über 200 Stationen umfassenden globalen GPS-Netzes des Beobachtungszeitraums 1994 bis 2007. Nach der Vorstellung der Grundprinzipien des GPS und seiner wesentlichen Fehlereinflüsse erfolgt die Beschreibung der Analyse der Beobachtungsdaten selbst. Sie umfasst die einheitliche Auswertung über den gesamten Zeitraum sowie Verbesserungen in der Modellierung der atmosphärischen Einflüsse und der Charakteristika der Sende- und Empfangsantennen sowie die Nutzung der Normalgleichungen zu Realisierung des ITRS. Der abgeleitete Terrestrische Referenzrahmen (TRF) wird Potsdam-Dresden-Reprocessing 2007 (PDR07) genannt. Zur Beurteilung der Genauigkeit und Zuverlässigkeit dieses TRF werden umfangreiche Analysen durchgeführt. So wird der PDR07 u.a. mit weiteren Realisierungen des ITRS, dem ITRF2000, dem ITRF2005 und den Realisierungen des International GNSS Service (IGS) IGb00 und IGS05, verglichen. Für eine Vielzahl geodynamischer Anwendungen werden GPS-Stationen in Messkampagnen beobachtet. Die hochgenaue Realisierung des ITRS in diesen regionalen GPS-Netzen ist für die geodynamische Interpretation der Ergebnisse zwingend erforderlich. Am Beispiel eines regionalen GPS-Netzes in der Antarktis wird untersucht, wie sich das ITRS in derartigen Netzen realisieren lässt und mit welcher Genauigkeit lineare Stationsbewegungen aus Kampagnenmessungen abgeleitet werden können. Im Anschluss werden die erhaltenen Bewegungsraten geodynamisch interpretiert: Aus den horizontalen Bewegungsraten wird die Bewegung der Antarktischen Kontinentalplatte im Konzept der Globaltektonik bestimmt und ihre innere Stabilität bewertet. Die vertikalen Stationsbewegungen werden genutzt, um Aussagen über rezente Krustendeformationen aufgrund glazialisostatischer Ausgleichsbewegungen und rezenter Massenvariationen des antarktischen Eises zu treffenThe geodetic observation techniques contribute in several ways to the research of the system Earth: On the one hand they observe the recent processes and their variations in time directly, on the other hand they provide the basis for a consistent description of all effects in a consistent geometrical and gravimetrical reference. Within the project Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG) the prerequisites for the combination of geodetic observation techniques, models and analysis strategies shall be created in order to enable a high accurate monitoring of the system Earth with consistent geodetic parameters. In this context the realization of geodetic reference systems with highest accuracy is a central task of the GGOS and subject of this thesis. At present, a common realization of the Terrestrial Reference System (TRS) consists of station positions according to a specific epoch and their linear changes with time. In this concept non-linear station motions yield to residual variations, which may be used for geoscientific interpretations. The natural origin of a global TRS, and this is also the case for the International Terrestrial Reference System (ITRS), is the center of mass of the system Earth (CM). This origin can be realized by observations of dynamic satellite techniques, such as GPS. In a consistent approach satellite orbits, stations positions and the lower degrees of harmonic surface mass load coefficients are estimated simultaneously. The ITRS is realized based on reprocessed observations of a global GPS network. In a joint effort TU Dresden, TU München and GFZ Potsdam analyzed the data of more than 200 stations of the observation time span 1994 to 2007. After an introduction to the basic principles of GPS and its major error sources the data analysis is described. This covers a homogeneous analysis over the entire period, improvements in atmosphere modeling and antenna phase center modeling as well as the usage of normal equations for the ITRS realization. The determined Terrestrial Reference Frame (TRF) is named Potsdam-Dresden-Reprocessing 2007 (PDR07). In order to assess the accuracy and stability of this TRF a variety of analyses is performed. For example, PDR07 is compared to other ITRS realizations, such as the ITRF2000, the ITRF2005 as well as the realizations of the International GNSS Service (IGS) IGb00 and IGS05. GPS campaign observations are often used to investigate geodynamic phenomena. The realization of the ITRS with highest accuracy in these regional GPS networks is essential for the geodynamic interpretation of the results. A regional GPS network in Antarctica is used to investigate the optimal way to realize the ITRS in such networks and the accuracy of linear station rates determined from campaign observations. Subsequently, the station rates are used for geodynamic interpretations: The horizontal station rates are used to determine the movement of the Antarctic Plate in the concept of global plate kinematics and to assess the inner stability of the Antarctic Plate. The vertical station rates are used to evaluate recent crustal deformations caused by glacial isostatic adjustment and recent mass changes of the Antarctic ice sheet
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Asgharzadeh, Mohammad Forman. "Geodynamical analysis of the Iranian Plateau and surrounding regions." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1173126914.
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Tusch, Jonas [Verfasser], Carsten [Gutachter] Münker, Daniel [Gutachter] Herwartz, and Kristoffer [Gutachter] Szilas. "Tungsten Isotope Constraints on Archean Geodynamics / Jonas Tusch ; Gutachter: Carsten Münker, Daniel Herwartz, Kristoffer Szilas." Köln : Universitäts- und Stadtbibliothek Köln, 2020. http://d-nb.info/1228534381/34.
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Painter, Clayton S. "Sequence Stratigraphy, Geodynamics, and Detrital Geo-Thermochronology of Cretaceous Foreland Basin Deposits, Western Interior U.S.A." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/307071.
Full textAbstract:
Three studies on Cordilleran foreland basin deposits in the western U.S.A. constitute this dissertation. These studies differ in scale, time and discipline. The first two studies include basin analysis, flexural modeling and detailed stratigraphic analysis of Upper Cretaceous depocenters and strata in the western U.S.A. The third study consists of detrital zircon U-Pb analysis (DZ U-Pb) and thermochronology, both zircon (U-Th)/He and apatite fission track (AFT), of Upper Jurassic to Upper Cretaceous foreland-basin conglomerates and sandstones. Five electronic supplementary files are a part of this dissertation and are available online; these include 3 raw data files (Appendix_A_raw_isopach_data.txt, Appendix_C_DZ_Data.xls, Appendix_C_UPb_apatite.xls), 1 oversized stratigraphic cross section (Appendix_B_figure_5.pdf), and 1 figure containing apatite U-Pb concordia plots (Appendix_C_Concordia.pdf). Appendix A. Subsidence in the retroarc foreland of the North American Cordillera in the western U.S.A. has been the focus of a great deal of research, and its transition from a flexural foreland basin, during the Late Jurassic and Early Cretaceous, to a dynamically subsided basin during the Late Cretaceous has been well documented. However, the exact timing of the flexural to dynamic transition is not well constrained, and the mechanism has been consistently debated. In order to address the timing, I produced new isopach maps from ~130 well log data points that cover much of Utah, Colorado, Wyoming and northern New Mexico, producing in the process, the most detailed isopach maps of the area. These isopach maps span the Turonian to mid-Campanian during the Late Cretaceous (~93–76 Ma). In conjunction with the isopach maps I flexurally modeled the Cordilleran foreland basin to identify when flexure can no longer account for the basin geometry and identified the flexural to dynamic transition to have occurred at 81 Ma. In addition, the dynamic subsidence at 81 Ma is compared to the position of the hypothesized Shatsky Oceanic Plateau and other proposed drivers of dynamic subsidence. I concluded that dynamic subsidence is likely caused by convection over the plunging nose of the Shatsky Oceanic Plateau. Appendix B. The second study is a detailed stratigraphic study of the Upper Cretaceous, (Campanian, ~76 Ma) Sego Sandstone Member of the Mesaverde Group in northwestern Colorado, an area where little research has been done on this formation. Its equivalent in the Book Cliffs area in eastern Utah has been rigorously documented and its distal progradation has been contrastingly interpreted as a result of active tectonism and shortening in the Cordilleran orogenic belt ~250 km to the west and to tectonic quiescence, flexural rebound in the thrust belt and reworking of proximal coarse grained deposits. I documented ~17 km of along depositional dip outcrops of the Sego Sandstone Member north of Rangely, Colorado. This documentation includes measured sections, paleocurrent analysis, a stratigraphic cross section, block diagrams outlining the evolution of environments of deposition through time, and paleogeographic maps correlating northwest Colorado with the Book Cliffs, Utah. The sequence stratigraphy of the Sego Sandstone Member in northwest Colorado is similar to that documented in the Book Cliffs area to the south-southwest, sharing three sequence boundaries. However, flood-tidal delta assemblages between fluvio-deltaic deposits that are present north of Rangely, Colorado are absent from the Book Cliffs area. These flood-tidal-delta assemblages are likely caused by a large scale avulsion event in the Rangely area that did not occur or was not preserved in the Book Cliffs area. In regards to tectonic models that explain distal progradation of the 76 Ma Sego Sandstone Member to be caused by tectonic quiescence and flexural rebound in the thrust belt, the first study shows that at 76 Ma, flexural processes were no longer dominant in the Cordilleran foreland, so it is inappropriate to apply models driven by flexure to the Sego Sandstone Member. Dynamic processes dominated the western U.S.A. during the Campanian, and flexural processes were subordinate. Appendix C. In order to test the tectonic vs. anti-tectonic basin-filling models for distal coarse foreland deposits mentioned above, the third study involves estimating lag times of Upper Jurassic to Upper Cretaceous conglomerates and sandstones in the Cordilleran foreland basin. Measuring lag time requires a good understanding of both the stratigraphic age of a deposit and the thermal history of sedimentary basin. To further constrain depositional age, I present twenty-two new detrital zircon U-Pb (DZ U-Pb) sample analyses, spanning Upper Jurassic to Upper Cretaceous stratigraphy in Utah, Colorado, Wyoming and South Dakota. Source exhumation ages can be measured using thermochronology. To identify a thermochronometer that measures source exhumation in the North America Cordillera, both zircon (U-Th)/He, on eleven samples, and apatite fission track (AFT) thermochronology, on eleven samples was performed. Typically, the youngest cooling age population in detrital thermochronologic analyses is considered to be a source exhumation signal; however, whether or not these apatites are exhumed apatites or derived from young magmatic and volcanic sources has been debated. To test this, I double dated the detrital AFT samples, targeting apatites with a young cooling age, using U-Pb thermochronology. Key findings are that the maximum depositional ages using DZ U-Pb match existing biostratigraphic and geochronologic age controls on basin stratigraphy. AFT is an effective thermochronometer for Lower to Upper Cretaceous foreland stratigraphy and indicates that source material was exhumed from >4–5 km depth in the Cordilleran orogenic belt between 118 and 66 Ma, and zircon (U-Th)/He suggests that it was exhumed from <8–9 km depth. Double dating apatites (with AFT and U-Pb) indicate that volcanic contamination is a significant issue; without having UPb dating of the same apatite grains, one cannot exclude the possibility that the youngest detrital AFT population is contaminated with significant amounts of volcanogenic apatite and does not represent source exhumation. AFT lag-times are 0 to 5 Myr with relatively steady-state to slightly increasing exhumation rates. We compare our data to orogenic wedge dynamics and subsidence histories; all data shows active shortening and rapid exhumation throughout the Cretaceous. Our lag-time measurements indicate exhumation rates of ~.9–>>1 km/Myr.
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Mendoza, Luciano, Gerardo Connon, and Andreas Richter. "Feuerland: Symptome einer aktiven Plattengrenze." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A28740.
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Weeraratne, Dayanthie Sakunthala. "Anomalous seismic and rheological behavior of the asthenosphere beneath oceanic and continental plates /." View online version; access limited to Brown University users, 2005. http://wwwlib.umi.com/dissertations/fullcit/3174690.
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Nunes, João Carlos Carreiro. "A actividade vulcânica na Ilha do Pico do Plistocénico Superior ao Holocénico-mecanismo eruptivo e hazard vulcânico." Phd thesis, Instituições portuguesas -- -Universidade dos Açores -- -Departamento de Geociências, 1999. http://dited.bn.pt:80/30404.
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Perez, José Aurélio Silva [UNESP]. "Campo de velocidade para as estações da RBMC e do IGS localizados na placa Sul-Americana: estimativa a partir do processamento de dados GPS." Universidade Estadual Paulista (UNESP), 2002. http://hdl.handle.net/11449/88547.
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perez_jas_me_prud.pdf: 977367 bytes, checksum: 6b9550e8932dce0b607ca29641e6f1ba (MD5)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Atualmente, com a evolução das tecnologias desenvolvidas para fins de posicionamento, especialmente nos casos que envolvem Geodésia Espacial, várias outras aplicações dessas tecnologias surgem a partir de pesquisas desenvolvidas por vários cientistas. Neste contexto, o GPS (Global Positioning System) destacase de forma impressionante, não só pela variada gama de aplicações em que pode ser utilizado, mas também pela precisão e acurácia dos resultados que podem ser obtidos pelo mesmo. Desta forma, o GPS como “ferramenta” para a Geodinâmica torna-se vital em aplicações que requerem alta precisão, tais como: monitoramento e análise de movimento e deformação das placas litosféricas, previsão de terremotos em regiões sismicamente ativas, entre outras. Um método bastante eficiente nestes casos é o Posicionamento por Ponto Preciso (PPP), adequado para a utilização de produtos GPS disponibilizados pelo IGS (International GPS Service) ou pelo JPL (Jet Propulsion Laboratory). Além disso, existem softwares adequados para esse tipo de posicionamento, bem como para a utilização dos produtos fornecidos pelo IGS e JPL. Este trabalho envolve, basicamente, a utilização do Posicionamento por Ponto Preciso para o processamento de dados de estações geodésicas, no intuito de se obter um campo de velocidades dessas estações, em nível intercontinental. Para tanto, torna-se necessário um prévio embasamento sobre os principais fenômenos geodinâmicos relacionados ao movimento de placas litosféricas, bem como uma fundamentação teórica sobre as observáveis envolvidas no GPS e as possíveis fontes de erro nele atuantes...
Nowadays, with the evolution of the technologies related to positioning, specially those involved with Spatial Geodesy, several applications of these technologies arose from the researches carried out by several scientists. In this context, the GPS (Global Positioning System) has been widely emphasized, not only because of the amount of applications in which it can be used, but also because of the precision and accuracy of the results that can be obtained. Thus, GPS as “tool” for Geodynamics becomes essential in applications where high precision is required, such as monitoring and analysis of movements and deformations of the tectonic plates, prevision of earthquakes at seismically active regions, and others. A method very efficient in these cases is the Precise Point Positioning (PPP), which is suitable for using the GPS products available by IGS (International GPS Service) or JPL (Jet Propulsion Laboratory). Moreover, there are appropriated softwares for applying this method of positioning, as well as for using products provided by IGS and JPL. The present work involves, basically, the use of PPP to processing a set of geodetic stations data, in order to obtain the velocity’s field of these stations involved in an intercontinental scope. In order to reach this aim, it was necessary a previous basis about the main geodynamic phenomena related to the tectonic plate’s movement, as well as the theoretical basis concerning the GPS observables and the possible sources of errors acting on them. In order to analyze the accuracy of the results, comparisons between the final geodetic solution and the results provided by others geodetic sources and geophysical models of plate movements have to be carried out. This procedure has been made in the present work, and preliminary results were obtained for the velocity’s field of the RBMC... (Complete abstract click electronic address below)
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Heimgartner, Michelle N. "The geophysical structure of the Sierra Nevada crustal root." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1442856.
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Ponraj, M. "Crustal deformation and geodynamics of India-Eurasia collision zone and adjoining regions from inversion of GPS and seismicity data." Thesis, IIG, 2010. http://localhost:8080/xmlui/handle/123456789/1594.
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Petrie, Meredith B. "Fluid Infiltration and Strain Localization in the Whitestone Anorthosite, Grenville Province, Ontario." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/PetrieMB2009.pdf.
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Perez, José Aurélio Silva. "Campo de velocidade para as estações da RBMC e do IGS localizados na placa Sul-Americana : estimativa a partir do processamento de dados GPS /." Presidente Prudente : [s.n.], 2002. http://hdl.handle.net/11449/88547.
Full textAbstract:
Resumo: Atualmente, com a evolução das tecnologias desenvolvidas para fins de posicionamento, especialmente nos casos que envolvem Geodésia Espacial, várias outras aplicações dessas tecnologias surgem a partir de pesquisas desenvolvidas por vários cientistas. Neste contexto, o GPS (Global Positioning System) destacase de forma impressionante, não só pela variada gama de aplicações em que pode ser utilizado, mas também pela precisão e acurácia dos resultados que podem ser obtidos pelo mesmo. Desta forma, o GPS como "ferramenta" para a Geodinâmica torna-se vital em aplicações que requerem alta precisão, tais como: monitoramento e análise de movimento e deformação das placas litosféricas, previsão de terremotos em regiões sismicamente ativas, entre outras. Um método bastante eficiente nestes casos é o Posicionamento por Ponto Preciso (PPP), adequado para a utilização de produtos GPS disponibilizados pelo IGS (International GPS Service) ou pelo JPL (Jet Propulsion Laboratory). Além disso, existem softwares adequados para esse tipo de posicionamento, bem como para a utilização dos produtos fornecidos pelo IGS e JPL. Este trabalho envolve, basicamente, a utilização do Posicionamento por Ponto Preciso para o processamento de dados de estações geodésicas, no intuito de se obter um campo de velocidades dessas estações, em nível intercontinental. Para tanto, torna-se necessário um prévio embasamento sobre os principais fenômenos geodinâmicos relacionados ao movimento de placas litosféricas, bem como uma fundamentação teórica sobre as observáveis envolvidas no GPS e as possíveis fontes de erro nele atuantes... (Resumo completo clicar acesso eletrônico abaixo)Abstract: Nowadays, with the evolution of the technologies related to positioning, specially those involved with Spatial Geodesy, several applications of these technologies arose from the researches carried out by several scientists. In this context, the GPS (Global Positioning System) has been widely emphasized, not only because of the amount of applications in which it can be used, but also because of the precision and accuracy of the results that can be obtained. Thus, GPS as "tool" for Geodynamics becomes essential in applications where high precision is required, such as monitoring and analysis of movements and deformations of the tectonic plates, prevision of earthquakes at seismically active regions, and others. A method very efficient in these cases is the Precise Point Positioning (PPP), which is suitable for using the GPS products available by IGS (International GPS Service) or JPL (Jet Propulsion Laboratory). Moreover, there are appropriated softwares for applying this method of positioning, as well as for using products provided by IGS and JPL. The present work involves, basically, the use of PPP to processing a set of geodetic stations data, in order to obtain the velocity's field of these stations involved in an intercontinental scope. In order to reach this aim, it was necessary a previous basis about the main geodynamic phenomena related to the tectonic plate's movement, as well as the theoretical basis concerning the GPS observables and the possible sources of errors acting on them. In order to analyze the accuracy of the results, comparisons between the final geodetic solution and the results provided by others geodetic sources and geophysical models of plate movements have to be carried out. This procedure has been made in the present work, and preliminary results were obtained for the velocity's field of the RBMC... (Complete abstract click electronic address below)
Orientador: João Francisco Galera Monico
Coorientador: João Carlos Chaves
Mestre
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Rülke, Axel. "Zur Realisierung eines terrestrischen Referenzsystems in globalen und regionalen GPS-Netzen." Doctoral thesis, Technische Universität Dresden, 2008. https://tud.qucosa.de/id/qucosa%3A25106.
Full textAbstract:
Die geodätischen Beobachtungsverfahren leisten auf verschiedene Weise Beiträge zur Erforschung des Systems Erde: Einerseits beobachten sie die rezenten Prozesse und ihre zeitlichen Variationen direkt, andererseit liefert sie die Grundlage für die konsistente Betrachtung aller Einflüsse in einem einheitlichen geometrischen und gravimetrischen Bezug. Das Projekt
des Global Geodetic Observing System (GGOS) der Internationalen Assoziation für Geodäsie (IAG) soll die Voraussetzungen zur Vereinigung der verschiedenen geodätischen Beobachtungsverfahren, Modelle und Auswertemethoden mit dem Ziel schaffen, mit einem konsistenten Satz geodätischer Parameter ein hochgenaues Monitoring des Systems Erde zu ermöglichen. Die Realisierung geodätischer Bezugssysteme mit höchsten Genauigkeitsansprüchen ist in diesem Kontext eine zentrale Aufgabe des GGOS und Thema der vorliegenden Arbeit.
In der derzeit üblichen Darstellung umfasst eine Realisierung des Terrestrischen Referenzsystems (TRS) Stationspositionen zu einer spezifischen Epoche und ihre linearen Änderungen mit der Zeit. In diesem Konzept führen alle nichtlinearen Stationsbewegungen zu residualen Abweichungen, die geowissenschaftlich interpretiert werden können. Der natürliche Ursprung eines globalen TRS, so auch des International Terrestrial Reference System (ITRS), liegt im Massezentrum des Systems Erde (CM). Mit Hilfe dynamischer Satellitenverfahren, wie GPS, lässt sich dieser Ursprung aus geodätischen Beobachtungen realisieren. In einem konsistenten Ausgleichungsansatz werden Satellitenbahnen, Stationspositionen und die in Kugelflächenfunktionen niedrigen Grades modellierte Auflastdeformation gemeinsam geschätzt.
Die Grundlage der Realisierung des ITRS bilden in einem gemeinsamen Projekt der TU Dresden, der TU München und des GFZ Potsdam reprozessierte Beobachtungen eines über 200 Stationen umfassenden globalen GPS-Netzes des Beobachtungszeitraums 1994 bis 2007. Nach
der Vorstellung der Grundprinzipien des GPS und seiner wesentlichen Fehlereinflüsse erfolgt die Beschreibung der Analyse der Beobachtungsdaten selbst. Sie umfasst die einheitliche Auswertung über den gesamten Zeitraum sowie Verbesserungen in der Modellierung der atmosphärischen Einflüsse und der Charakteristika der Sende- und Empfangsantennen sowie die Nutzung der Normalgleichungen zu Realisierung des ITRS. Der abgeleitete Terrestrische Referenzrahmen (TRF) wird Potsdam-Dresden-Reprocessing 2007 (PDR07) genannt. Zur Beurteilung der Genauigkeit und Zuverlässigkeit dieses TRF werden umfangreiche Analysen durchgeführt. So wird der PDR07 u.a. mit weiteren Realisierungen des ITRS, dem ITRF2000, dem ITRF2005 und den Realisierungen des International GNSS Service (IGS) IGb00 und IGS05, verglichen.
Für eine Vielzahl geodynamischer Anwendungen werden GPS-Stationen in Messkampagnen beobachtet. Die hochgenaue Realisierung des ITRS in diesen regionalen GPS-Netzen ist für die geodynamische Interpretation der Ergebnisse zwingend erforderlich. Am Beispiel eines regionalen GPS-Netzes in der Antarktis wird untersucht, wie sich das ITRS in derartigen Netzen realisieren lässt und mit welcher Genauigkeit lineare Stationsbewegungen aus Kampagnenmessungen abgeleitet werden können. Im Anschluss werden die erhaltenen Bewegungsraten geodynamisch interpretiert: Aus den horizontalen Bewegungsraten wird die Bewegung der Antarktischen Kontinentalplatte im Konzept der Globaltektonik bestimmt und ihre innere
Stabilität bewertet. Die vertikalen Stationsbewegungen werden genutzt, um Aussagen über rezente Krustendeformationen aufgrund glazialisostatischer Ausgleichsbewegungen und rezenter Massenvariationen des antarktischen Eises zu treffen.The geodetic observation techniques contribute in several ways to the research of the system Earth: On the one hand they observe the recent processes and their variations in time directly, on the other hand they provide the basis for a consistent description of all effects in a consistent geometrical and gravimetrical reference. Within the project Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG) the prerequisites for the combination of geodetic observation techniques, models and analysis strategies shall be created in order to enable a high accurate monitoring of the system Earth with consistent geodetic parameters. In this context the realization of geodetic reference systems with highest accuracy is a central task of the GGOS and subject of this thesis. At present, a common realization of the Terrestrial Reference System (TRS) consists of station positions according to a specific epoch and their linear changes with time. In this concept non-linear station motions yield to residual variations, which may be used for geoscientific interpretations. The natural origin of a global TRS, and this is also the case for the International Terrestrial Reference System (ITRS), is the center of mass of the system Earth (CM). This origin can be realized by observations of dynamic satellite techniques, such as GPS. In a consistent approach satellite orbits, stations positions and the lower degrees of harmonic surface mass load coefficients are estimated simultaneously. The ITRS is realized based on reprocessed observations of a global GPS network. In a joint effort TU Dresden, TU München and GFZ Potsdam analyzed the data of more than 200 stations of the observation time span 1994 to 2007. After an introduction to the basic principles of GPS and its major error sources the data analysis is described. This covers a homogeneous analysis over the entire period, improvements in atmosphere modeling and antenna phase center modeling as well as the usage of normal equations for the ITRS realization. The determined Terrestrial Reference Frame (TRF) is named Potsdam-Dresden-Reprocessing 2007 (PDR07). In order to assess the accuracy and stability of this TRF a variety of analyses is performed. For example, PDR07 is compared to other ITRS realizations, such as the ITRF2000, the ITRF2005 as well as the realizations of the International GNSS Service (IGS) IGb00 and IGS05. GPS campaign observations are often used to investigate geodynamic phenomena. The realization of the ITRS with highest accuracy in these regional GPS networks is essential for the geodynamic interpretation of the results. A regional GPS network in Antarctica is used to investigate the optimal way to realize the ITRS in such networks and the accuracy of linear station rates determined from campaign observations. Subsequently, the station rates are used for geodynamic interpretations: The horizontal station rates are used to determine the movement of the Antarctic Plate in the concept of global plate kinematics and to assess the inner stability of the Antarctic Plate. The vertical station rates are used to evaluate recent crustal deformations caused by glacial isostatic adjustment and recent mass changes of the Antarctic ice sheet.