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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.

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.

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.

Most of the periglacial environments of the Earth are experiencing enormous changes in the context of the current climate warming. These changes have strong impacts on both the thermal regime in the subsurface and on geomorphological processes taking place. In order to assess how periglacial regions will develop in the future, it is important to know the recent subsurface structures and to understand complex interactions between different surface and subsurface characteristics. Small-scale heterogeneities play an important role in this context, as they make large-scale predictions regarding future developments very difficult. In this study, these small-scale heterogeneities in surface and subsurface characteristics were examined within the area of individual landforms but also at a regional scale within the Mackenzie Delta Region. In addition to surface-subsurface interactions, the focus was on the geomorphological landforms of pingos and retrogressive thaw slumps. Pingos are key features of polar permafrost environments, are very sensitive to changes in environmental conditions and, hence, are interesting periglacial features to study surface-subsurface interactions. In contrast to this, retrogressive thaw slumps are a result of rapid thaw of ice-rich permafrost and arise more frequently in recent decades due to climate change. To enhance knowledge about the formation and development of these landforms, detailed, three-dimensional investigations were performed at a retrogressive thaw slump in the Richardson Mountains, at a hydrostatic pingo on the Tuktoyaktuk Peninsula and at a hydraulic pingo in the more southern Ogilvie Mountains. Quasi-three-dimensional electrical resistivity tomography (ERT), ground-penetrating radar (GPR) and frost probing surveys were conducted to obtain high-resolution three-dimensional information about the subsurface structures in the area of the landforms. Additional drone surveys and monitoring of ground surface temperatures provided information about surface characteristics and thermal regimes in different relief positions. The aim of this methodological approach was to measure various surface and subsurface properties in the area of the different landforms in order to analyse their interactions and relationships in more detail. In the area of the pingos, the aim was to better understand the internal structures of the landforms in particular and to determine their relationship to the local hydrology. At the retrogressive thaw slump the main objective was the investigation of relationships between subsurface structures like ice content variabilities or active layer thickness and the spatiotemporal slump development. At the retrogressive thaw slump site, the approach revealed strong heterogeneities in subsurface properties in the area close to the retreating headwall. Variations in ice content and partly unfrozen layers seem to affect the spatiotemporal slump development and the local hydrology. The local hydrology is additionally affected by a strong permafrost table topography, which was revealed by frost probing and GPR. Spatial and temporal variations in slump development were obtained from satellite data but also from two high-resolution digital elevation models derived from drone surveying. These data provide evidence on an acceleration of slump growth but also confirmed material accumulation in the slump floor indicating slump stabilisation. At the two pingo sites the focus was on the three-dimensional internal structures of the features and the delineation of frozen and unfrozen areas but also of potential massive ice bodies. At the hydrostatic pingo, a massive ice core could be detected but its position was not centred below the pingo. Instead, it is located below the western flank, whereas the eastern flank is underlain by ice-poor permafrost and partly unfrozen sediments. This contrasts with theory and raises some questions about pingo formation in general. At the hydraulic pingo, probably unfrozen areas could be detected below the centre of the pingo, which may enable ascend of artesian water. This fits to theory but the measurements failed to detect a clearly delineated, massive ice core at this site. The results of both pingo sites are among the first high-resolution, three-dimensional subsurface models of pingos and provide valuable insights to enhance knowledge about pingo formation. The more regional analysis of surface-subsurface relationships in the Mackenzie Delta Region was performed based on data collected at 25 reconnaissance sites along a north-south transect between the Richardson Mountains in the south and Richards Island and the Tuktoyaktuk Peninsula in the north. Six sites were located on Richards Island, whereas the other sites were located along the Dempster and the Inuvik-Tuktoyaktuk Highways. At each site, two-dimensional ERT surveys, frost probing and vegetation height measurements were performed. Year-round measurements of ground surface temperatures at nearly all sites completed the approach and allowed the investigation of site-specific ground thermal regimes. The ERT measurements revealed strong subsurface heterogeneities on various spatial scales but also some spatial patterns in subsurface resistivity, which seem to be related to recent morphology. The investigation of relationships between various surface parameters and the subsurface parameters of active layer thickness or electrical resistivity indicated a scale-dependent relationship between various parameters. On small spatial scales (< 10 m) there are only low to moderate correlations between surface and subsurface properties. On larger spatial scales several moderate and strong correlations could be detected using the site-specific mean values. This concerns especially relationships between the active layer thickness and several relief-related but also hydrological and vegetation-related parameters. Regarding the electrical resistivity of the subsurface, moderate or strong correlations are restricted to the hydro-geographical parameters of flow accumulation and topographic wetness index. The results of this study contribute to a better understanding of three-dimensional subsurface structures and heterogeneities in the area of pingos and retrogressive thaw slumps and therefore gain knowledge about the development of these landforms. The investigation of surface-subsurface interactions enhanced understanding of complex system interactions in periglacial environments, which should contribute to a better prediction of future landscape development in the Mackenzie Delta Region but also in other periglacial environments, especially in the context of ongoing global warming. / Die meisten Periglazialgebiete der Erde erfahren im Rahmen der aktuellen Klimaerwärmung weitreichende Änderungen, die einen erheblichen Einfluss sowohl auf das thermische Regime im Untergrund als auch auf die ablaufenden geomorphologischen Prozesse haben. Um abschätzen zu können, wie sich die Periglazialgebiete in Zukunft entwickeln, ist es notwendig, die aktuellen Untergrundeigenschaften zu kennen und komplexe Interaktionen zwischen Oberflächen- und Untergrundeigenschaften zu verstehen. Vor allem kleinräumige Heterogenitäten sind in diesem Zusammenhang besonders wichtig, da sie großskalige Vorhersagen bezüglich der zukünftigen Entwicklung deutlich erschweren. Im Rahmen dieser Studie wurden ebendiese kleinräumigen Heterogenitäten der Oberflächen- und Untergrundeigenschaften im Bereich einzelner Landformen aber auch auf einer größeren räumlichen Skala in der Mackenzie-Delta Region untersucht. Neben den Oberflächen-Untergrund-Interaktionen waren vor allem die geomorphologischen Formen der Pingos und Taurutschungen von Interesse. Pingos gehören zu den indikativen Landformen des polaren Permafrostes, sind sehr sensitiv gegenüber Veränderungen der äußeren Einflüsse und daher auch interessant für die Untersuchung von Wechselwirkungen zwischen Untergrund und Oberfläche. Im Gegensatz dazu resultieren Taurutschungen aus dem schnellen Abtauen von eisreichem Permafrost, welche in den letzten Dekaden durch die anhaltende Klimaerwärmung gehäuft auftraten. Um die Entstehung und Entwicklung dieser Landformen besser zu verstehen, wurden detaillierte dreidimensionale Untersuchungen an einer Taurutschung in den Richardson Mountains, einem hydrostatischen Pingo auf der Tuktoyaktuk-Halbinsel und an einem hydraulischen Pingo in den weiter südlich gelegenen Ogilvie Mountains durchgeführt. Um hochaufgelöste, dreidimensionale Informationen über die Untergrundstrukturen im Bereich der Landformen zu erhalten, wurden quasi-dreidimensionale, geoelektrische Widerstandstomographie (ERT), Georadar (GPR) und Messungen der Auftauschichtmächtigkeit durchgeführt. Zusätzlich wurden Drohnenbefliegungen sowie Monitoring von Oberflächentemperaturen durchgeführt, um weitere Informationen zu Oberflächeneigenschaften, dem Relief und dem thermischen Regime in verschiedenen Reliefpositionen zu erhalten. Ziel dieses methodischen Ansatzes war es, verschiedene Oberflächen- und Untergrundeigenschaften im Bereich der verschiedenen Landformen zu messen, um deren Wechselwirkungen und Beziehungen genauer zu analysieren. Im Bereich der Pingos ging es vor allem darum, die internen Strukturen der Landformen besser zu verstehen und ihre Beziehung zur lokalen Hydrologie zu untersuchen. An der untersuchten Taurutschung konnte der Ansatz starke Heterogenitäten der Untergrundeigenschaften im Bereich angrenzend an die zurückweichende Stirnwand der Rutschung aufzeigen. Sowohl Variationen im Eisgehalt als auch teilweise ungefrorene Schichten im Untergrund scheinen die raumzeitliche Entwicklung der Rutschung sowie die lokale Hydrologie zu beeinflussen. Die Hydrologie an diesem Standort ist zudem noch durch eine starke Topographie der Permafrosttafel beeinflusst, die durch Messung der Auftauschichtmächtigkeit sowie GPR-Messungen detektiert werden konnte. Die räumlichen und zeitlichen Variabilitäten in der Entwicklung der Rutschung wurden mit Hilfe von Satellitendaten und zwei hochaufgelösten, drohnenbasierten Geländemodellen abgeleitet. Diese Daten deuten auf eine Beschleunigung des Rutschungswachstums hin, konnten aber auch eine Materialakkumulation im Bereich vor der rückschreitenden Erosionsstirn bestätigen, welche als Indiz für eine Stabilisation gesehen werden kann. An den beiden Pingos lag der Fokus auf deren dreidimensionalen internen Strukturen und der Abgrenzung von gefrorenen und ungefrorenen Bereichen sowie von potentiellen massiven Eiskörpern. Am hydrostatischen Pingo konnte ein massiver Eiskörper nachgewiesen werden, allerdings ist seine Position nicht zentral unter dem Pingo lokalisiert. Stattdessen ist er eher unter der westlichen Flanke des Pingos sowie dessen angrenzender Umgebung lokalisiert, während die östliche Flanke von eisarmem Permafrost und teilweise ungefrorenen Sedimenten unterlagert ist. Dies steht ein Stück weit in Kontrast zur bisher geltenden Theorie und wirft neue Fragen hinsichtlich der Pingo-Genese auf. Am hydraulischen Pingo konnten mutmaßlich ungefrorene Bereiche zentral unter dem Pingo detektiert werden, welche möglicherweise den Aufstieg von artesischem Grundwasser ermöglichen. Dies passt zur Theorie, wobei allerdings mit Hilfe der Messungen kein klar abgegrenzter, massiver Eiskern detektiert werden konnte. Die Ergebnisse dieser Studien gehören zu den ersten hochaufgelösten, dreidimensionalen Untergrundmodellen von Pingos und bieten daher wertvolle Einblicke, um das Verständnis zur Entstehung von Pingos zu verbessern. An der untersuchten Taurutschung war das Hauptziel die Untersuchung von Zusammenhängen zwischen Untergrundeigenschaften wie beispielsweise relativen Eisgehaltsänderungen oder der Auftauschichtmächtigkeit und der raumzeitlichen Entwicklung der Taurutschung. Die eher großskalige Analyse von Wechselwirkungen zwischen Oberfläche und Untergrund in der Mackenzie-Delta Region wurde auf Basis von 25 Messprofilen entlang eines Nord-Südtransektes zwischen den Richardson Mountains im Süden und Richards Island bzw. der Tuktoyaktuk Halbinsel im Norden durchgeführt. Sechs dieser Untersuchungsgebiete lagen auf Richards Island, wohingegen die restlichen Profile entlang des Dempster- und Inuvik-Tuktoyaktuk-Highways lagen. An jeder dieser Lokalitäten wurde ein zweidimensionales ERT-Profil, sowie die Mächtigkeit der Auftauschicht und die Vegetationshöhe gemessen. Ganzjährige Messungen der Oberflächentemperatur an nahezu allen Standorten ermöglichte zudem die Untersuchung lokalitätsspezifischer thermischer Regime. Die ERT-Messungen konnten auf verschiedenen räumlichen Skalen starke Heterogenitäten aber auch scheinbar reliefbedingte räumliche Muster im oberflächennahen Untergrund detektieren. Die Untersuchung von Wechselwirkungen zwischen verschiedenen Oberflächenparametern mit den Untergrundparametern der Auftauschichtmächtigkeit sowie der elektrischen Widerstände zeigte einige skalenabhängige Zusammenhänge zwischen verschiedenen Parametern. Auf kleinen räumlichen Skalen (<10 m) gibt es scheinbar nur schwache bis moderate Zusammenhänge zwischen Oberflächen- und Untergrundeigenschaften. Auf räumlich etwas größeren Skalen (~200 m) konnten unter der Verwendung von lokalen Mittelwerten hingegen einige moderate und auch starke Zusammenhänge nachgewiesen werden. Dies betrifft vor allem Zusammenhänge zwischen der Auftauschichtmächtigkeit und reliefbezogenen, hydro-geographischen, oder vegetationsbezogenen Parametern. In Bezug auf die elektrischen Widerstände des Untergrundes beschränken sich moderate und stärkere Zusammenhänge lediglich auf die hydro-geographischen Merkmale der Einzugsgebietsgröße sowie des topographischen Feuchteindizes (TWI). Die Ergebnisse dieser Studie tragen zu einem besseren Verständnis der dreidimensionalen Untergrundstrukturen und Heterogenitäten im Bereich von Pingos und Taurutschungen bei und helfen so, deren Entstehung und Entwicklung besser zu verstehen. Die Untersuchung von Wechselwirkungen zwischen Oberflächen- und Untergrundeigenschaften kann zudem das Verständnis bezüglich komplexer Systeminteraktionen in Periglazialgebieten verbessern. Dies soll dazu beitragen, die zukünftige Landschaftsentwicklung in der Mackenzie-Delta Region, aber auch in den anderen Periglazialgebieten der Erde besser einschätzen zu können – besonders auch im Rahmen der anhaltenden Klimaerwärmung. / Most of the periglacial environments on Earth are experiencing enormous changes during the ongoing climate warming. These changes strongly affect the thermal regime in the subsurface as well as geomorphological processes taking place. To assess how periglacial environments will develop in the future, it is important to know the recent subsurface structures and to understand their complex relationships to surface characteristics. Small-scale heterogeneities play an important role in this context, as they make large-scale predictions regarding future development very difficult. This study presents a multimethodological approach to reveal relationships between surface and subsurface properties and their respective small-scale distribution along a north-south transect throughout the Mackenzie Delta Region in Northwest Canada. In addition, high-resolution three-dimensional investigations of two pingos and a retrogressive thaw slump reveal new insights in the morphological development of these landforms.

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

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.

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 (...).

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.