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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Lower Palaeozoic geology of western White Bay, Newfoundland

Lock, Brian Edward January 1969 (has links)
No description available.
2

The physiology and behaviour of fish from a freshwater, eutrophic lake, Slapton Ley, Devon

Scott, Dawn Michelle Scott January 2003 (has links)
No description available.
3

Femtosecond thermomodulation measurements of transport and relaxation in metals and superconductors

January 1990 (has links)
Stuart D. Brorson. / Also issued as Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1990. / Includes bibliographical references. / Supported in part by fellowships from the IBM Corporation and the AT&TCorporation.
4

A UTILIZAÇÃO DE NORMAS DE COMPETÊNCIA EM JULGAMENTOS MONOCRÁTICOS E O ARTIGO 557 DO CPC

VIRGOLINO, P. S. P. 15 May 2012 (has links)
Made available in DSpace on 2016-08-29T11:13:18Z (GMT). No. of bitstreams: 1 tese_5706_Dissertação Pedro Virgolino.pdf: 1459395 bytes, checksum: 6ed36d33d0faea26c167ce5788c6b4ca (MD5) Previous issue date: 2012-05-15 / O objetivo desse trabalho é analisar os poderes conferidos ao relator pelo art. 557 do CPC e a compatibilidade desse dispositivo infraconstitucional com os princípios e garantias contidos na Carta de 1988. E também verificar se de fato essa norma é capaz de conferir a celeridade pretendida pelo legislador. Foram traçados os contornos do princípio do julgamento colegiado nos tribunais e o efeito que esse princípio produz na interpretação da regra de competência definida no art. 557. São definidas todas as hipóteses de julgamento unipessoal previstas no ar. 557 do CPC e os limites da atuação do relator. Tratou-se do cabimento de agravo interno contra a decisão do relator, o procedimento de julgamento desse recurso e a aplicabilidade da multa prevista no §2º desse artigo. A pesquisa foi desenvolvida por meio do levantamento do vasto material doutrinário produzido sobre o art. 557 e dos precedentes judiciais a respeito dessa matéria. Foi realizada pesquisa empírica, por meio de amostragem, das decisões do relator proferidas pelo Tribunal de Justiça do Estado do Espírito Santo no julgamento de recurso de apelação. Como resultado, foi possível detectar que o art. 557 não necessariamente representa técnica apta a acelerar o processo. Também foi constatado em diversos casos que o relator decidiu sem observar rigorosamente os limites do art. 557.
5

Influence of climate change in the water availability over the eastern side of Colombia

Molina Rincon, Oscar David 22 July 2020 (has links)
This PhD is focused on the eastern region of Colombia and the practical development of this work was composed of three stages that lead to three different articles which are the main body of this study. The first stage was focused on a systematic review of the climate characteristics over the last decades at eastern Colombia including a data survey and evaluation of the historical available data records. In the second stage, the Statistical Downscaling Model (SDSM) was used as a tool for downscaling meteorological data statistically over four representative water districts at the eastern side of Colombia. Here, data from the two Global Climate Models CanESM2 and IPSL-CM5A-MR, which are part of the CMIP5-project have been used to project future maximum and minimum temperature, precipitation and relative humidity for the periods 2021–2050 and 2071–2100. For both models, the Representative Concentration Pathways RCP2.6 and RCP8.5 were considered, representing two different possible future emission trajectories and radiative forcings. In the third stage, the results of the second stage together with the hydrological model BROOK90 and complementary data were utilized to determine the future changes in the water balance components in the previously selected four water districts in Eastern Colombia.
6

Provenance of detrital zircons on Quaternary slope deposits in the south-western USA (Great Basin and Colorado Plateau)

Richter-Krautz, Jana 07 September 2021 (has links)
This thesis results from a pilot study which, driven by repeatedly surprising results, opens up a reliable method of geochronology for Quaternary research. There have been repeated attempts to expand the limits of normal use of U-Pb dating. Geologists typically use U-Pb dating on detrital zircons (DZ) for dating and provenance studies on rocks older than the Cenozoic era. We tested several tephra layers in Utah and New Mexico, USA, with published 40 Ar/ 39 Ar ages between 1.3 and 1.6 Ma and found that the ages derived from clustered U-Pb dating are reliable, even though they were discordant. We used one of these tephra layers in the La Sal Mountains, Utah, to assign a minimum age to slope deposit layers (cover beds) underlying the tephra bed. In doing so, we discovered that we could not only identify unconformities between layers by means of palaeopedology. But that - although they were similar to one another regarding physical and chemical properties - they were not the same at all in terms of the provenance of their aeolian matter as derived from U-Pb analysis of detrital zircons, as one could actually assume. The source of aeolian matter mixed to these layers has changed decisively from layer to layer. The findings also allowed tentatively assigning palpable source areas for each layer. Since this had demonstrated the feasibility of a provenance approach, we then extended our study regionally to cover beds of the central Great Basin (GB) and the northern Colorado Plateau (CP). Using a published sequence-stratigraphic approach based upon stratigraphically consistent phases of soil development, we attempted to study cover beds from the same two Upper Quaternary time slices. We expanded our range of methods by end-member modelling analyzes (EMMA) and the analysis of surface and shape of detrital zircons. We used statistical methods such as multidimensional scaling (MDS) and density functions (probability density functions and kernel density estimations) to visualize similarities and distances of age distributions. The MDS and the density functions showed very clearly that the patterns of ages between the GB and the CP can be divided into two groups that differ from one another. This is probably due to different transport cascades of the zircons to and within both areas. Due to the lack of databases on the morphology of in-situ zirconia, it is not yet possible to draw precise conclusions about transport routes from them, although we have probably been able to identify traces of several stages of aeolian transport on many zircons. Conclusions can also be drawn about detrital zircons that were transported to the sampling point purely by the kinetic energy of volcanic eruptions during the Cretaceous (Cordilleran magmatic arc) and the Paleogene (strong volcanism within the study area). Moreover, we can show main similarities of the layers across the CP. Although they are separated spatially and temporally, they have a similar age distribution. The only exception here is the upper La Sal Mountains profile, for which I have several assumptions as to why this is so. We did not have enough conclusions for the reconstruction of the palaeoenvironmental conditions during the layer and soil formation phases; further investigations will have to follow. However, we show that a provenance study on Quaternary layers and further conclusions from the results are possible and would like to condense this approach for the study area in the future, but also try to transfer it to other study areas.:Abstract .......................................................................................................................3 Kurzfassung ................................................................................................................5 Contents ......................................................................................................................7 List of figures ............................................................................................................ 11 List of tables ............................................................................................................. 13 List of abbreviations and units .................................................................................. 14 1 Introduction ........................................................................................................... 16 1.1 Research questions ........................................................................................... 16 1.2 Cover beds ......................................................................................................... 17 1.3 Palaeosols .......................................................................................................... 17 1.4 Study area .......................................................................................................... 18 1.5 Zircons ............................................................................................................... 21 1.6 Thesis format ...................................................................................................... 23 2 Capability of U-Pb dating of zircons from Quaternary tephra: Jemez Mountains, NM, and La Sal Mountains, UT, USA ....................................................................... 24 2.1 Abstract .............................................................................................................. 25 2.2 Kurzfassung ....................................................................................................... 25 2.3 Introduction ........................................................................................................ 26 2.4 Geological setting ............................................................................................... 27 2.4.1 Jemez Mountains, New Mexico ...................................................................... 27 2.4.2 La Sal Mountains, Utah ................................................................................... 30 2.5 Methods ............................................................................................................. 30 2.6 Results and discussion ..................................................................................... 33 2.6 Conclusions ........................................................................................................ 38 Data availability ........................................................................................................ 38 Competing interests.................................................................................................. 38 Acknowledgements .................................................................................................. 38 2.7 References ......................................................................................................... 39 3 Cover beds older than the mid-Pleistocene revolution and the provenance of their aeolian components, La Sal Mountains, Utah, USA ........................................ 42 3.1 Abstract .............................................................................................................. 43 3.2 Introduction ........................................................................................................ 43 3.3 Material and methods ........................................................................................ 44 3.3.1 The La Sal Mountains tephra layer ................................................................. 44 3.3.2 Cover beds and palaeosols............................................................................. 45 3.3.3 Samples and analyses .................................................................................... 46 3.4 Results and discussion ...................................................................................... 49 3.5 Conclusions ....................................................................................................... 56 Acknowledgments ................................................................................................... 58 Summary information A. Supplementary data ......................................................... 58 3.6 References ........................................................................................................ 58 4 Zircon provenance of Quaternary cover beds using U-Pb dating: regional differences in the south-western USA ...................................................................... 63 4.1 Abstract .............................................................................................................. 64 4.2 Introduction ........................................................................................................ 65 4.3 Materials ............................................................................................................. 66 4.3.1 Study areas ..................................................................................................... 66 4.3.2 Stratigraphy and sampling sites ...................................................................... 68 4.3.3 Palaeolake deposits ........................................................................................ 71 4.3.4 Potential sources of detrital zircons ................................................................ 71 4.4 Methods ............................................................................................................. 75 4.4.1 End-member modelling of grainsize composition ........................................... 75 4.4.2 U-Pb dating ..................................................................................................... 75 4.4.3 Zircon dimensions and surfaces ..................................................................... 77 4.4.4 Statistical and graphical representations ........................................................ 78 4.5 Results and discussion ...................................................................................... 79 4.5.1 Aeolian contribution to cover beds .................................................................. 79 4.5.2 Zircon morphology .......................................................................................... 82 4.5.3 Age distributions of detrital zircons ................................................................. 88 4.5.4 Multidimensional scaling (MDS) ..................................................................... 94 4.6 Conclusions ....................................................................................................... 98 Appendix ................................................................................................................ 102 Acknowledgements ................................................................................................ 102 4.7 References ....................................................................................................... 103 5 Extended summary .............................................................................................. 118 5.1 Synthesis .......................................................................................................... 118 5.2 Regional differences and similarities ................................................................ 123 5.3 Outlook ............................................................................................................. 128 6 Supplementary Information ................................................................................. 130 6.1 Supplementary material chapter ‘Capability of U-Pb dating of zircons from Quaternary tephra: Jemez Mountains, NM, and La Sal Mountains, UT, USA’........ 130 6.1.1 Raw data electron microprobe analyses of glass shards from tephra layers .131 6.1.2 Raw data U-Pb ratios and calculated ages for all samples ............................137 6.2 Supplementary material chapter 3 ‘Cover beds older than the mid-Pleistocene revolution and the provenance of their eolian components, La Sal Mountains, Utah, USA’ .............................................................................................................. 160 6.3 Supplementary material chapter 4 ................................................................... 175 6.3.1 SI1 Raw U-Pb ratios and calculated ages ......................................................175 6.3.2 SI 3 Grainsize diagrams of samples of the present study (except for PL)......266 6.3.3 SI 4 Zircon morphology data .........................................................................269 6.3.3.1 Great Basin .................................................................................................269 6.3.3.2 Colorado Plateau ........................................................................................289 7 References (excluding chapters 2, 3 and 4) ....................................................... 308 8 Acknowledgements ............................................................................................. 312 / Diese Arbeit ist das Ergebnis einer Pilotstudie, die aufgrund immer wieder neuer, unerwarteter Ergebnisse eine zuverlässige geochronologische Methode für die Quartärforschung eröffnet. Es wurde mehrfach versucht, die üblichen Grenzen der Verwendung der U-Pb-Datierung zu erweitern. In der Geologie wird die U-Pb-Datierung an detritischen Zirkonen (DZ) normalerweise für Datierungs- und Provenienzstudien an Gesteinen, die älter als das Känozoikum sind, eingesetzt. Wir haben mehrere Tephra-Schichten in Utah und New Mexico, USA, mit veröffentlichten 40 Ar/ 39 Ar-Altern zwischen 1.3 und 1.6 Ma getestet und festgestellt, dass die Alter, die aus den Clustern der U-Pb-Datierungen abgeleitet wurden, zuverlässig sind, obwohl sie diskordant waren. Wir haben eine dieser Tephra-Schichten in den La Sal Mountains, Utah, verwendet, umlagernden Deckschichten ein Mindestalter zuzuweisen. Dabei stellten wir fest, dass wir nicht nur mittels Paläopädologie Schichtgrenzen zwischen Schichten ausweisen konnten. Sondern dass sie sich, obwohl sie sich in Bezug auf physikalische und chemische Eigenschaften ähneln, in Bezug auch auf die Herkunft ihres äolischen Materials (abgeleitet aus der U-Pb-Analyse der DZ) überhaupt nicht glichen, wie man eigentlich annehmen könnte. Die Herkunft des eingemischten äolischen Materials hat sich von Schicht zu Schicht entscheidend verändert. Die Ergebnisse ermöglichten es auch, jeder Schicht konkrete wahrscheinliche Liefergebiete zuzuweisen. Da dies die Möglichkeit einer Provenienz-Analyse belegt hatte, erweiterten wir unsere Studie regional auf Deckschichten des zentralen Great Basin (GB) und des nördlichen Colorado Plateaus (CP). Unter Verwendung eines publizierten sequenz-stratigraphischen Ansatzes, der auf stratigraphisch konsistenten Phasen der Bodenentwicklung basiert, haben wir versucht, Deckschichten aus denselben beiden oberen quartären Zeitscheiben zu untersuchen. Wir erweiterten unser Methodenspektrum um End Member-Modellierung (EMMA) und die Analyse der Oberfläche und Form von DZ. Wir verwendeten statistische Methoden wie mehrdimensionale Skalierung (MDS) und Dichtefunktionen (Wahrscheinlichkeitsdichtefunktionen und Kerndichteschätzungen), um Ähnlichkeiten und Abstände von Altersverteilungen zu visualisieren. MDS und Dichtefunktionen zeigten deutlich, dass GB und CP unterschiedliche Altersspektren aufweisen. Dies ist wahrscheinlich auf unterschiedliche Transportkaskaden der Zirkone in beide und innerhalb beider Gebiete zurückzuführen. Aufgrund des Fehlens von Datenbanken zur Morphologie von gesteinsbürtigen Zirkonen kann man daraus noch keine genauen Rückschlüsse über Transportwege ziehen, obwohl wir wahrscheinlich an vielen Zirkonen Spuren mehrerer Schritte des äolischen Transports identifizieren konnten. Es liegen auch DZ vor, die vermutlich ausschließlich durch die kinetische Energie von Vulkanausbrüchen während der Kreidezeit (Cordilleran Magmatic Arc) und des Paläogens (starker Vulkanismus innerhalb des Untersuchungsgebiets) zum Probenahmepunkt transportiert wurden. Darüber hinaus können wir Ähnlichkeiten zwischen den verschiedenen Schichten im CP zeigen. Obwohl sie räumlich und zeitlich getrennt sind, haben sie eine ähnliche Altersverteilung. Die einzige Ausnahme hiervon ist das Profil der höheren La Sal Mountains, wofür es mehrere mögliche Gründe gibt. Wir konnten nicht genügend Erkenntnisse für die Rekonstruktion der paläoökologischen Bedingungen während der Schicht- und Bodenbildungsphasen gewinnen; weitere Untersuchungen müssen folgen. Wir zeigen jedoch, dass eine Provenienzstudie an quartären Schichten und weiterreichende Schlussfolgerungen möglich sind, und möchten diesen Ansatz für das Untersuchungsgebiet in Zukunft verdichten, aber auch versuchen, ihn auf andere Untersuchungsgebiete zu übertragen.:Abstract .......................................................................................................................3 Kurzfassung ................................................................................................................5 Contents ......................................................................................................................7 List of figures ............................................................................................................ 11 List of tables ............................................................................................................. 13 List of abbreviations and units .................................................................................. 14 1 Introduction ........................................................................................................... 16 1.1 Research questions ........................................................................................... 16 1.2 Cover beds ......................................................................................................... 17 1.3 Palaeosols .......................................................................................................... 17 1.4 Study area .......................................................................................................... 18 1.5 Zircons ............................................................................................................... 21 1.6 Thesis format ...................................................................................................... 23 2 Capability of U-Pb dating of zircons from Quaternary tephra: Jemez Mountains, NM, and La Sal Mountains, UT, USA ....................................................................... 24 2.1 Abstract .............................................................................................................. 25 2.2 Kurzfassung ....................................................................................................... 25 2.3 Introduction ........................................................................................................ 26 2.4 Geological setting ............................................................................................... 27 2.4.1 Jemez Mountains, New Mexico ...................................................................... 27 2.4.2 La Sal Mountains, Utah ................................................................................... 30 2.5 Methods ............................................................................................................. 30 2.6 Results and discussion ..................................................................................... 33 2.6 Conclusions ........................................................................................................ 38 Data availability ........................................................................................................ 38 Competing interests.................................................................................................. 38 Acknowledgements .................................................................................................. 38 2.7 References ......................................................................................................... 39 3 Cover beds older than the mid-Pleistocene revolution and the provenance of their aeolian components, La Sal Mountains, Utah, USA ........................................ 42 3.1 Abstract .............................................................................................................. 43 3.2 Introduction ........................................................................................................ 43 3.3 Material and methods ........................................................................................ 44 3.3.1 The La Sal Mountains tephra layer ................................................................. 44 3.3.2 Cover beds and palaeosols............................................................................. 45 3.3.3 Samples and analyses .................................................................................... 46 3.4 Results and discussion ...................................................................................... 49 3.5 Conclusions ....................................................................................................... 56 Acknowledgments ................................................................................................... 58 Summary information A. Supplementary data ......................................................... 58 3.6 References ........................................................................................................ 58 4 Zircon provenance of Quaternary cover beds using U-Pb dating: regional differences in the south-western USA ...................................................................... 63 4.1 Abstract .............................................................................................................. 64 4.2 Introduction ........................................................................................................ 65 4.3 Materials ............................................................................................................. 66 4.3.1 Study areas ..................................................................................................... 66 4.3.2 Stratigraphy and sampling sites ...................................................................... 68 4.3.3 Palaeolake deposits ........................................................................................ 71 4.3.4 Potential sources of detrital zircons ................................................................ 71 4.4 Methods ............................................................................................................. 75 4.4.1 End-member modelling of grainsize composition ........................................... 75 4.4.2 U-Pb dating ..................................................................................................... 75 4.4.3 Zircon dimensions and surfaces ..................................................................... 77 4.4.4 Statistical and graphical representations ........................................................ 78 4.5 Results and discussion ...................................................................................... 79 4.5.1 Aeolian contribution to cover beds .................................................................. 79 4.5.2 Zircon morphology .......................................................................................... 82 4.5.3 Age distributions of detrital zircons ................................................................. 88 4.5.4 Multidimensional scaling (MDS) ..................................................................... 94 4.6 Conclusions ....................................................................................................... 98 Appendix ................................................................................................................ 102 Acknowledgements ................................................................................................ 102 4.7 References ....................................................................................................... 103 5 Extended summary .............................................................................................. 118 5.1 Synthesis .......................................................................................................... 118 5.2 Regional differences and similarities ................................................................ 123 5.3 Outlook ............................................................................................................. 128 6 Supplementary Information ................................................................................. 130 6.1 Supplementary material chapter ‘Capability of U-Pb dating of zircons from Quaternary tephra: Jemez Mountains, NM, and La Sal Mountains, UT, USA’........ 130 6.1.1 Raw data electron microprobe analyses of glass shards from tephra layers .131 6.1.2 Raw data U-Pb ratios and calculated ages for all samples ............................137 6.2 Supplementary material chapter 3 ‘Cover beds older than the mid-Pleistocene revolution and the provenance of their eolian components, La Sal Mountains, Utah, USA’ .............................................................................................................. 160 6.3 Supplementary material chapter 4 ................................................................... 175 6.3.1 SI1 Raw U-Pb ratios and calculated ages ......................................................175 6.3.2 SI 3 Grainsize diagrams of samples of the present study (except for PL)......266 6.3.3 SI 4 Zircon morphology data .........................................................................269 6.3.3.1 Great Basin .................................................................................................269 6.3.3.2 Colorado Plateau ........................................................................................289 7 References (excluding chapters 2, 3 and 4) ....................................................... 308 8 Acknowledgements ............................................................................................. 312
7

Ψηφιοποίηση πολιτισμικού αποθέματος του χωριού Αγ. Θωμά Ηρακλείου Κρήτης και προβολή του στον ιστότοπο του πολιτιστικού συλλόγου Αγ. Θωμά "Ο Λόγιος" www.logios.gr, μέσω νέων τεχνολογιών διαδικτύου ανοικτού κώδικα / Cultural wealth digitization of St. Thomas village at Heraklion, Crete and its demonstration on the web through the web site www.logios.gr using open source web technologies

Μπαντουβάς, Ιωάννης 06 October 2011 (has links)
Η διπλωματική εργασία στόχο έχει την ανάδειξη του πολιτισμικού πλούτου του χωριού Άγιος Θωμάς Ηρακλείου Κρήτης και προβολή του στον παγκόσμιο Ιστό. Για να πραγματοποιηθεί αυτό θα χρησιμοποιήσουμε τεχνολογίες διαδικτύου ανοιχτού κώδικα καθώς και περιφερειακές συσκευές απεικόνισης και σάρωσης ώστε να επιτύχουμε τη βέλτιστη ψηφιοποίηση του υλικού που διαθέτουμε. Το υλικό μας είναι τόσο φωτογραφίες, βίντεο και ηχητικά αποσπάσματα, όσο και γραπτά κείμενα που αφορούν την ιστορία του χωριού αλλά και τη σημερινή του ζωή. Μέσω των νέων τεχνολογιών αποσκοπούμε στην διατήρησή τους σε κατάσταση αναλλοίωτη στο χρόνο και προσβάσιμη από παντού και από οποιονδήποτε ενδιαφερόμενο. Ο ιστότοπος που θα δημιουργηθεί θα αποτελεί ένα κόμβο ενημέρωσης και περιήγησης στο χωριό και την ιστορία του παράλληλα με την ενημέρωση που θα παρέχει στο χρήστη για τις προσεχείς εκδηλώσεις του πολιτιστικού συλλόγου. Με λίγα λόγια θα είναι ένας τόπος συγκέντρωσης όλων όσων κατάγονται από τον Άγιο Θωμά προσφέροντάς τους ένα πλούσιο αποθετήριο της πολιτισμικής κληρονομιάς του τόπου, σε μια προσπάθεια να έρθουν πιο κοντά στο χωριό από όποιο μέρος του κόσμου κι αν βρίσκονται. Χρησιμοποιώντας γλώσσες προγραμματισμού όπως PHP, CSS, JavaScript, HTML, βάσεις δεδομένων MySQL καθώς και Content Magement Systems όπως η Joomla θα προσπαθήσουμε να δείξουμε πως είναι εφικτό να φτάσουμε σε άρτια προβολή και παρουσίαση του ψηφιοποιημένου υλικού με μικρό κόστος και σε μικρό χρονικό διάστημα αφήνοντας παρακαταθήκη για περαιτέρω εργασία και μοντελοποίηση του συγκεκριμένου CMS ώστε να τεθεί στην υπηρεσία του πολιτισμού. Ψηφιοποίηση πολιτισμικού αποθέματος του χωριού Αγ. Θωμά Ηρακλείου Κρήτης και προβολή του στον ιστότοπο του πολιτιστικού συλλόγου Αγ. Θωμά «Ο Λόγιος» www.logios.gr, μέσω νέων τεχνολογιών διαδικτύου ανοικτού κώδικα. / The MSc thesis aims to highlight the cultural wealth of the village of St Thomas Heraklion and demonstrate it on the web. To do this we will use Internet technologies and open source peripherals imaging and scanning to achieve optimal digitization of materials available. Our material is so photos, videos and audio clips, and writings on the history of the village and its current life. Through new technologies we intend to keep them in a state invariant in time and accessible from anywhere and from anyone interested. The site created will be a hub for information and tour the village and its history along with information that will provide the user about forthcoming events of the cultural association. In short it is a meeting place for all those descended from St. Thomas, offering a rich repository of cultural heritage site in an effort to come closer to the village from anywhere in the world they are. Using programming languages such as PHP, CSS, JavaScript, HTML, MySQL Databases and Content Magement Systems like Joomla will try to show that it is possible to reach a well-promotion and presentation of digitized material at low cost and short time leaving legacy for further work and modeling of specific CMS to put at the service of culture.
8

4D paleoenvironmental evolution of the Early Triassic Sonoma Foreland Basin (western USA) / Evolution paléoenvironnementale 4D du Bassin Foreland de Sonoma au Trias Inférieur (Ouest-USA)

Caravaca, Gwénaël 10 July 2017 (has links)
Introduction : la Terre au Trias inférieur et la reconquête après l’extinction fini-PermienneSitué après la limite entre le Paléozoïque et le Mésozoïque, le Trias inférieur est un intervalle court (~4Ma seulement ; Ovtcharova et al., 2006 ; Galfetti et al., 2007a ; Baresel et al., 2017). Lors de la transition entre le Permien et le Trias (PTB), la configuration tectonique de la Terre était différente, et la plupart des masses continentales étaient rassemblées en un seul super continent, la Pangée, lui-même entouré par un unique océan global, la Panthalassa (e.g., Murphy & Nance, 2008 ; Murphy et al., 2009 ; Stampfli et al., 2013).Lors de cette transition et durant le Trias inférieur, un évènement volcanique majeur, la mise en place de la grande province ignée de Sibérie (e.g., Ivanov et al., 2009, 2013), a conduit à l’émission de grande quantité de gaz à effet de serre (e.g., Galfetti et al., 2007b ; Romano et al., 2013). Ceux-ci ont contribué à l’acidification de la colonne d’eau et à l’augmentation des températures consécutivement à l’injection de CO2 dans l’atmosphère (e.g., Galfetti et al., 2007b ; Sun et al., 2012 ; Romano et al., 2013).Les perturbations environnementales qui en découlèrent ont eu des conséquences sur les milieux de dépôts associés à cette période, mais également sur les écosystèmes. Elles sont supposées avoir contribué à la mise en place de conditions délétères pour les organismes et avoir perduré durant tout le Trias inférieur, restreignant ainsi la rediversification biologique d’après-crise (e.g., Pruss & Bottjer, 2004 ; Fraiser & Bottjer, 2007 ; Bottjer et al., 2008 ; Algeo et al., 2011 ; Meyer et al., 2011 ; Bond & Wignall, 2014 ; Song et al., 2014).La limite PT fut le théâtre de la plus importante et la plus destructrice crise biologique du Phanérozoïque, et fut responsable de la disparition de plus de 90% des espèces marines (Raup, 1979), ou encore de la perte d’environ 50% des familles de tétrapodes continentaux (Benton & Newell, 2014), pour ne citer que ces deux exemples. De nombreux groupes ont été oblitérés durant cette extinction, comme par exemple les groupes caractéristiques du Paléozoïque tels que les coraux tabulés ou encore les trilobites (Sepkoski, 2002). Cependant, si la Vie a failli s’éteindre à l’aube du Mésozoïque, celle-ci a tout de même pu se reconstruire, au prix d’une rediversification communément admise comme lente et difficile dans des conditions environnementales délétères (e.g., Twitchett, 1999 ; Fraiser & Bottjer, 2007 ; Meyer et al., 2011 ; Chen & Benton, 2012). De grands paradigmes sont couramment associés à la rediversification du Trias inférieur (illustrés dans la Figure R.1a) :La présence de taxons « désastre », représentant des organismes opportunistes et généralistes qui auraient proliféré à la suite de la libération de niches écologiques laissées vacantes par les métazoaires disparus (e.g. ; Schubert & Bottjer, 1992, 1995 ; Rodland & Bottjer, 2001 ; He et al., 2007) ;Des faciès dit « anachroniques », composés de récifs exclusivement microbiens tels ceux trouvés dans les dépôts Précambriens (e.g., Schubert & Bottjer, 1992 ; Woods et al., 1999 ; Pruss & Bottjer, 2005 ; Pruss et al., 2005 ; Woods, 2009) ;Un effet « Lilliput », soit un nanisme généralisé des faunes présentes (e.g., Urbanek, 1993 ; Hautmann & Nützel, 2005 ; Payne, 2005 ; Twitchett, 2007 ; Fraiser et al., 2011 ; Metcalfe et al., 2011 ; Song et al., 2011) ;Une anoxie/euxinie généralisée dans le domaine marin, y compris littoral (e.g., Isozaki, 1997 ; Meyer et al., 2011 ; Song et al., 2012 ; Grasby et al., 2013).Fig. R.1 : a) Représentation synthétique des principaux paradigmes communément acceptés pour la rediversification biologique au cours du Trias inférieur. b) Représentation synthétique de ces mêmes paradigmes, révisés selon les données récemment recueillies dans le bassin ouest-américain (d’après Brayard, 2015). Inf. : inférieur ; m. : moyen ; s./sup. : supérieur (...). / In the wake of the Mesozoic, the Early Triassic (~251.95 Ma) corresponds to the aftermath of the most severe mass extinction of the Phanerozoic: the end-Permian crisis, when life was nearly obliterated (e.g., 90% of marine species disappeared). Consequences of this mass extinction are thought to have prevailed for several millions of years, implying a delayed recovery lasting the whole Early Triassic, if not more.Several paradigms have been established and associated to a delayed biotic recovery scenario expected to have resulted from harsh and deleterious paleoenvironments. These paradigms include a global anoxia in the marine realm, a “Lilliput” effect, and the presence of “disaster” taxa and “anachronistic” facies. However, recent works have shown a more complex global scheme for the Early Triassic recovery, and that a reevaluation of these paradigms was needed. Especially, new data from the western USA basin were critical in re-addressing these paradigms.The western USA basin is the result of a long tectono-sedimentary history that started 2 Gyr ago by the amalgamation of different lithospheric terranes forming its basement. A succession of orogenies and quiescence phases led to the formation of several successive basins in the studied area, and traces of this important geodynamical activity are still present today. The Sonoma orogeny occurred about 252 Ma in response to the eastward migration of drifting arcs toward the Laurentian craton. As a result, compressive constrains lead to the obduction of the Golconda Allochthon above the west-Pangea margin in present-day Nevada. Emplacement of this topographic load provoked the lithosphere flexuration beneath present-day Utah and Idaho to form the Sonoma Foreland Basin (SFB) studied in this work.The SFB record an excellent fossil and sedimentary record of the Early Triassic. A relatively high and complex biotic diversity has been observed there leading to describe a rapid and explosive recovery for some groups (e.g., ammonoids) in this basin after the end-Permian crisis. The sedimentary record is also well developed and has been studied extensively for a long time. Overall, these studies notably documented a marked difference between the northern and southern sedimentary succession within the basin, whose origin was poorly understood.This work therefore aims to characterize the various depositional settings in the Early Triassic SFB, as well as their paleogeographical distribution. Their controlling factors are also studied based on an original integrated method using sedimentological, paleontological, geochemical, geodynamical, structural and cartographic analyses. Aside the fossil and sedimentary discrepancy between the northern and the southern parts of the SFB, geochemical analyses provide new insights supporting this N/S dichotomy. This study also questions the validity of the geochemical signal as a tool for global correlation, as it appears to mainly reflect local forcing parameters.The geodynamical framework of the SFB was also investigated along with a numerical modelling of the rheological behavior of the basin. This work distinguishes the northern and southern parts of the basin based on markedly distinct tectonic subsidence rates during the Early Triassic: ~500 m/Myr in the northern part vs ~100m/Myr in the southern part. Origin of this remarkable difference is found in inherited properties of the basin basement itself. Indeed, different ages and therefore, rheological behaviors (i.e., rigidity to deformation and flexuration) of the basement lithospheric terranes act as a major controlling factor over the spatial distribution of the subsidence, and therefore of the sedimentary deposition. The lithosphere heritage is thus of paramount importance in the formation, development and spatio-temporal evolution of the SFB.This work leads to a new paleogeographical representation of the Sonoma Foreland Basin and its multi-parameter controlling factors (...).
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Altération et minéralisation d'uranium à Shea Creek (Ouest Athabasca, Saskatchewan, Canada) : vers un nouveau modèle génétique de gisement / Clay alteration and uranium mineralization in the Shea Creek area in the Athabasca basin, Saskatchewan, Canada : toward a new model of genesis of unconformity related uranium deposits

Uri, Freddy 13 December 2012 (has links)
Shea Creek est un gisement d'uranium liée à la discordance entre un socle métamorphique et des roches sédimentaires d'origine fluviatile, d'âge Paléo-protérozoïque et situé dans la partie ouest du bassin d'Athabasca. Ce gisement majeur est le plus profond connu actuellement dans le bassin (entre 680 m et 1000 m de profondeur). Il rassemble en un même lieu tous les types de minéralisation associés à une discordance connus de par le monde. Cette étude s'appuie sur l'analyse de plus de 1200 échantillons du halo d'altération qui entoure le gisement et sur l'utilisation des données d'exploration minière. L'objectif est double. Il s'agit d'une part de déterminer des guides sédimentologiques, pétrographiques, minéralogiques et géochimiques pour la prospection des corps minéralisés en zone profonde et d'autre part d'utiliser ces critères pour construire une représentation tridimensionnelle simplifiée (minéralisation et halo d'altération) permettant de préciser le modèle génétique de ce gisement profond. La localisation des différentes zones minéralisées dépend non seulement des phénomènes d'altération liés aux circulations hydrothermales contrôlées par la tectonique, mais aussi de la nature du remplissage sédimentaire et de son évolution diagénétique. L'architecture de la zone minéralisée de Shea Creek montre que les corps minéralisés sont localisés dans des structures en grabben remplies par des alternances de grès propres et de grès argileux souvent préservés de la compaction et de l'altération. La signature minéralogique et géochimique de ces grès suggère un apport provenant de l'érosion de paléo-altérites continentales (régolithe). La très forte concentration en défauts d'ir / Shea Creek is an unconformity-type uranium deposit located in the west part of Atabaska basin. It is related to an unconformity between a metamorphic basement and sedimentary rocks of fluvial origin, of paleoproterozoic age. Shea Creek's particularity is to be the deepest ore deposit ever known in the basin (between 680 m and 1000 m deep). It gathers all types of unconformity hosted mineralization known. More than 1200 samples, taken from halo alteration around the deposit, were analyzed and mining exploration data were used for this study. First, the aim was to determine the markers for prospection of mineral elements in deep area: sedimentological, petrographical, geochemical and mineralogical types. Then, it was to build a simple three-dimensional model (mineralization and alteration halo) using these criteria in order to precise the genetic pattern of this deep deposit. The location of mineralized areas depends on tectonic deformation, on sedimentary filling and diagenetic development. The morphology of Shea Creek’s ore deposit shows clearly that mineralization is located in the grabbens composed by clean sandstones and clay sandstones, often preserved from compaction and alteration phenomena. The mineralogical and geochemical signature of these clay sandstones suggests a contribution from the erosion of continental paleo-alterite (regolith). Beside, the great concentration of radiation induced defects suggests the presence in abundance of uranium in the grabbens from sedimentary state.
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"NE BIS IN IDEM" : En komparativ studie av svensk och norsk konventionstillämpning

Bengtsson, John, Karlsson, Tobias January 2008 (has links)
<p>I Europakonventionen finns ett förbud mot att en person skall kunna bli straffad för ett brott där denne redan blivit slutligt dömd eller frikänd. Det innebär alltså i praktiken ett förbud mot dubbelbestraffning, eller som principen också benämns – ”ne bis in idem”. Detta förbud har flera gånger varit föremål för prövning i såväl Europadomstolen som i nationella domstolar. Målen har gällt allt från rattfylleri till miljösanktioner. Det denna uppsats behandlar är dock relationen mellan skattetillägg och skattebrott.</p><p>Svensk lagstiftning och praxis kring de parallella sanktionerna har studerats utifrån en komparativ studie med Norge som jämförelseobjekt. Tanken är att jämförelsen i första hand skall ge en fördjupad bild av de svenska förhållandena och den svenska tillämpningen av konventionen samt vad det skulle innebära om Sverige införde ett subjektivt rekvisit i skattetilläggslagstiftningen.</p><p>Det svenska skattetillägget syftar till att främja uppgiftslämnandet hos skattskyldiga samt att avlasta åklagarmyndigheten från lindrigare fall av skatteundandragande. Skattetillägg kan bli aktuellt vid lämnande av oriktig uppgift eller vid skönstaxering och påförs enbart på objektiva grunder. Det finns med andra ord inget krav på uppsåt eller oaktsamt beteende från den skattskyldige. Skattetilläggskommittén kom i en utredning med ett förslag om att införa ett subjektivt rekvisit vid påförande av skattetillägg. Detta förslag anammades dock inte av regeringen som dock valde att klargöra och utveckla de redan befintliga befrielsegrunderna innehållande subjektiva inslag. Den främsta skillnaden gentemot den norska motsvarigheten är att man i Norge valt att indela denna i allmän respektive förhöjd tilleggsskatt. Den allmänna tilleggsskatten liknar i huvudsak det svenska skattetillägget, medan det vid den förhöjda tilleggsskatten krävs ytterligare ett rekvisit i form av uppsåt eller grov oaktsamhet. De båda ländernas skattebrottslagstiftning är i det närmaste identisk, vilket innebär att de innehåller såväl objektiva som subjektiva rekvisit.</p><p>Den ovan nämnda principen ”ne bis in idem” återfinns i sjunde tilläggsprotokollets artikel 4 och har påverkat avgöranden angående de svenska och norska sanktionssystemen på olika sätt. Det svenska sanktionssystemet har genom avgöranden i såväl Europadomstolen som svenska domstolar inte ansetts strida mot dubbelbestraffningsförbudet. Domstolarna har som främsta argument framhållit att påföljderna skiljer sig åt i sina väsentliga element, genom att skattebrott kräver uppsåt. I Norge går avgörandena från Høyesterett isär beroende på om det handlar om allmän eller förhöjd tilleggsskatt. Även här tar domstolen i första hand sikte på om påföljdernas rekvisit skiljer sig åt. Både de svenska och norska domstolarna har även diskuterat vad som innefattas av begreppen i artikel 4 i sjunde tilläggsprotokollet och artikel 6 samt förhållandet mellan dessa begrepp.</p><p>Sverige och Norge tolkar inte konventionens artiklar olika utan skillnaderna beror snarare på nationell lagstiftning. Skulle Sverige införa ett subjektivt rekvisit i skattetilläggslagstiftningen skulle med stor sannolikhet reglerna, i likhet med den norska förhöjda tilleggsskatten, strida mot principen ”ne bis in idem” i Europakonventionen.</p>

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