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1
Forest, Richard C. « Structures and metamorphism of Ptarmigan Creek area, Selwyn Range, B.C ». Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63337.
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Herren, Eveline. « Structures, deformation and metamorphism of the Zanskar area (Ladakh, NW Himalaya) / ». [S.l.] : [s.n.], 1987. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8419.
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Goswami, Sudipta. « Inverted metamorphism in the Sikkim-Darjeeling Himalaya : structural, metamorphic and numerical studies ». Thesis, University of Cambridge, 2005. https://www.repository.cam.ac.uk/handle/1810/284048.
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The structural and metamorphic evolution of the Darjeeling-Sikkim Himalaya, a “classical” region of inverted metamorphism in the Himalaya, has been investigated by field studies combined with 2-D numerical modelling of the thermal evolution. In the Himalaya, an orogen-wide zone of inverted isograds is spatially associated with the Main Central Thrust (MCT). In the Sikkim-Darjeeling region, an inverted metamorphic field gradient is indicated by garnet-grade rocks in the upper Lesser Himalaya (LH), which increase in grade to sillimanite + K-feldspar assemblages in the middle to upper structural levels of the Higher Himalayan Crystallines (HHC). Metamorphic breaks in the “Barrovian sequence” have been established between the garnet- and sillimanite-bearing rocks in the Darjeeling region and between the kyanite-staurolite schists and biotite-sillimanite schists in Sikkim. Since the accurate location of the MCT is critical to constraining the metamorphic evolution of the Higher and Lesser Himalaya, a number of criteria are used in defining the MCT zone in this region. These include lithologic contrasts, increase in non-coaxial deformation features towards the MCT zone and geomorphology. The MCT forms a zone of distributed ductile deformation that has propagated southwards with time, resulting in a 3-10 km wide zone, containing rocks from both the Higher and Lesser Himalaya. Four episodes of deformation and two metamorphic events have been identified in the HHC. Textural evidence and garnet zoning profiles indicate a single episode of prograde metamorphism, but four deformation events in the MCT zone and the LH. Garnet zoning profiles from the HHC indicate retrograde equilibrium. M1 resulted in a peak assemblage of prismatic sillimanite + K-feldspar as well as muscovite dehydration melting resulting in millimetre to centimetre scale leucosomes, while M2 is associated with rapid exhumation of the HHC during simultaneous movement along the MCT and the South Tibetan Detachment System (STDS) forming decompression textures in metabasic boudins and pelites.
4
McFarlane, Christopher R. M. « Metamorphism, structure and tectonic evolution of the Matthew Creek Metamorphic Zone, Kimberley, British Columbia ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0024/MQ31363.pdf.
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Ambrose, Tyler. « Structure, metamorphism, and tectonics of the northern Oman-UAE ophiolite and underlying metamorphic sole ». Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:e9520624-0f91-4c9d-a9b9-e9e2fc5d5517.
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Ophiolites - thrust sheets of oceanic lithosphere that have been emplaced onto the continental margin - provide the opportunity to explore the structure and genesis of oceanic crust. As many ophiolites formed above subduction zones, they also allow for the investigation of mantle wedge and subduction interface processes. This the- sis examines the Oman-United Arab Emirates (UAE) ophiolite, which is the largest and most intensely studied ophiolite on Earth. Three distinct problems are addressed. (1) Recent research has proposed that the architecture and tectonic evolution of the ophiolite in the UAE differs from in Oman. In Chapter 2, I test this hypothesis by integrating new geological mapping and field observations with previously published maps of the ophiolite in the UAE. My results indicate that the ophiolite is gently folded, but otherwise largely intact. I demonstrate that the architecture of the ophi- olite in the UAE is not significantly different from in Oman. Thus, there is no basis for a different tectonic evolution as recently proposed. (2) Observations from exper- iments and small-scale natural shear zones indicate that volumetrically-minor phases can control strain localization. In Chapter 3, I test the hypothesis that minor phases control strain-localisation at plate boundaries. To do so, I analyzed peridotites from the base of the ophiolite, a palaeosubduction interface. My results demonstrate that minor phases limited olivine grain growth, which led to rheological weakening. (3) The mechanisms by which metamorphic soles detached from the downgoing slab and accreted to the hanging-wall mantle is unclear. In Chapter 4, I examine a transect across the metamorphic sole in the UAE. My results reveal that granulite formation was more extensive than is typically considered. I propose that granulite formation resulted in rheological strengthening, which caused the subduction interface to migrate into the downgoing slab and accrete the metamorphic sole.
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Standley, Carl E. « Banda forearc metamorphic rocks accreted to the Australian continental margin : detailed analysis of the Lolotoi Complex of East Timor / ». Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1696.pdf.
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Walker, James David. « The structure and metamorphic evolution of the High Himalayan Slab in SE Zanskar and NW Lahaul ». Thesis, University of Oxford, 1998. http://ora.ox.ac.uk/objects/uuid:fc8b8fd3-e155-4f2f-9256-3667c2b31f4f.
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This thesis attempts to unravel the complex thermal and structural history of part of the High Himalayan Slab in NW India and combines reconnaissance-style field structural mapping of an area covering ~10,000 km2 with petrography, microstructural analysis, thermobarometry and geochronology techniques. The results of this work show that the oldest protoliths of the High Himalayan Slab are at least Cambrian in age and that they may have experienced a major pre-Himalayan metamorphism at c.500 Ma. The youngest protoliths are Mesozoic in age (the Tandi Group) and demonstrate that the High Himalayan Slab represents the metamorphosed equivalents of the Tibetan Sedimentary Series. Metamorphism was achieved via substantial crustal shortening and thickening following the India-Asia collision at 50-54 Ma ago. Phase relationships demonstrate that metamorphism was a regional Barrovian-type event associated with the growth of biotite-, garnet-, staurolite-, kyanite- and sillimanite-bearing assemblages in metapelites. Quantitative thermobarometry demonstrates that near-peak conditions of c.6-8 kbar and 550-650°C were attained in the deepest exposed levels. Growth of metamorphic assemblages was underway by at least 30 Ma, as indicated by U-Pb ages of metamorphic monazites. Exhumation of the High Himalayan Slab was achieved through a combination of extensional unroofing along major detachments (namely the Zanskar Shear Zone), thermal doming, thrusting along the Main Central Thrust and surface erosion. Exhumation is closely associated with the growth of sillimanite- and cordierite-bearing assemblages in pelites and the generation and emplacement of crustal melt leucogranites in the upper parts of the slab. U-Pb dating of accessory phases from one of the crustal melt leucogranites (the Gumburanjon leucogranite) constrains its crystallisation and emplacement age at c.21-22 Ma. This is only slightly older than its 40Ar/39Ar muscovite and biotite cooling ages of c.20-21 Ma, which is attributed to the emplacement of the Gumburanjon leucogranite into the immediate footwall of the ZSZ. Field and geochronological data therefore support a strong temporal and spatial relationship between upper crustal melting and extension in a convergent orogen.
8
Miller, Martin Gregg. « Structural and kinematic evolution of the Badwater Turtleback, Death Valley, California / ». Thesis, Connect to this title online ; UW restricted, 1992. http://hdl.handle.net/1773/6716.
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Daczko, Nathan Robert. « The Structural and Metamorphic evolution of cretaceous high-P granulites, Fiordland, New Zealand ». University of Sydney. Geosciences, 2002. http://hdl.handle.net/2123/822.
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Fiordland is located southwest of South Island of New Zealand. The field area of this thesis is in northern Fiordland, at the boundary of pristine arc rocks (Median Tectonic Zone) and a belt of Paleozoic paragneisses and orthogneisses of variable age that represent the metamorphosed paleo-Pacific Gondwana margin.
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Gupta, Saibal. « Structure and metamorphism of Sikinos, Cyclades, Greece ». Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363344.
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Lawrence, Robert William. « The structure and metamorphism of the Irindina supracrustal assemblage on the western side of the Entia Dome, Harts Range, central Australia / ». Title page, contents and summary only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phl4225.pdf.
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Thesis (Ph. D.)--University of Adelaide, Dept. of Geology and Geophysics, 1987.Typescript. Maps in back pocket of v. 1. Microfiches in back pocket of v. 2. Microfiches contain petrographic descriptions, total rock XRF analyses and microprobe analyses. Includes bibliographical references (leaves 160-183 (v. 2)).
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Kassos, Gabriel Philip Steltenpohl Mark G. « Structural, isotropic, and kinematic analysis of eclogite-facies shear zones and associated structures, Lofoten, North Norway ». Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Geology_and_Geography/Thesis/Kassos_Gabriel_39.pdf.
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Hurdle, E. J. « Stratigraphy, structure and metamorphism of Archean rocks, Clan Lake, N.W.T ». Thesis, University of Ottawa (Canada), 1985. http://hdl.handle.net/10393/4875.
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Magyarosi, Zsuzsanna. « Metamorphism of the Proterozoic rocks associated with the Sudbury Structure ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0007/MQ32431.pdf.
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Dawes, Ian Peter. « Structure and metamorphism in the Dalradian of NW Connemara, Ireland ». Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264310.
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Vitale, Brovarone Alberto. « From rifting to orogen : structure of Alpine Corsica and inheritance of rifting-related architectures in HP terranes ». Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20029/document.
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La Corse Alpine offre une section complète du prisme orogénique alpin où la plupart des équivalents des unités décrites dans les Alpes Occidentales peuvent être trouvés sur une section de 40 km. Les minéraux d'haute pression sont exceptionnellement bien préservés, particulièrement la lawsonite, offrant un accès unique à la compréhension de zones de subduction. La Corse alpine est formée par une pile complexe d’unités métamorphiques d'origine continentale et océanique. Ces unités ont été interprétées soit comme des mélanges tectoniques complexes formés pendant la subduction alpine, soit comme les parties plus continues de lithosphère continentale et-ou océanique. Les rares estimations de condition PT sur des larges régions de la chaîne résultent en plusieurs incertitudes dans l'identification des limites séparant les unités qui ont subi des évolutions tectono-métamorphiques différentes et, par conséquent, dans la définition d'une architecture complète de la chaîne. Les données de terrain, structurelles et métamorphiques obtenues dans cette étude aux différentes échelles suggèrent que la chaîne de la Corse alpine est caractérisée par une forte conservation de structures pré-alpin, de la micro-échelle à l'échelle de la chaîne, malgré la déformation intense associée avec le métamorphisme, qui a localement donné les conditions du facies éclogitique et lawsonite. En détail, seulement neuf domaines tectono-métamorphiques homogènes ont été identifiés. Ces terrains peuvent être attribué aux domaines paléogéographiques différents qui ont subi des évolutions tectono-métamorphiques différentes. Malgré ça, les données géochronologiques fournies pendant cette étude indiquent que la Corse alpine résulte d'une évolution complexe, étant caractérisée par la signature claire tant de la tectonique alpine Eocène, à 35 Ma, que de la tectonique apennine, à 25 Ma. Les résultats fournis dans cette thèse contribuent non seulement à la compréhension des processus de subduction et de formation de montagnes, mais donnent aussi des contraintes importantes pour déchiffrer les systèmes Tethys-Alpes et Alpes-ApennineAlpine Corsica offers a complete section through the Alpine orogenic wedge where most equivalent of the units described in the Western Alps may be found over a 40 km section. High-pressure mineral assemblages are exceptionally well preserved, especially lawsonite, offering a unique access to the understanding of deeply subducted terranes.Alpine Corsica consists of a complex stack of variably metamorphosed units of continental and Tethys-derived material. These units have been interpreted either as complex tectonic mixing formed during the Alpine subduction, or as more continuous portions of continental and/or oceanic lithosphere. The lack of detailed PT estimates over wide regions of the belt results in several uncertainties in identifying the boundaries separating units that experienced different tectono-metamorphic evolutions and, consequently, in the definition of an exhaustive architecture of the belt.Field, structural and metamorphic data collected in this study at different scales suggest that the Alpine Corsica belt is characterized by a high preservation of pre-Alpine sctructures, from the micro-scale up the scale of the belt, despite the intense deformation essociated with metamorphism, which locally reached lawsonite-eclogite metamorphism. In particular, only nine homogeneous tectono-metamorphic domains have been identified. These terranes can be referred to different paleogeographic domains that experienced different tectono-metamorphic evolutions.Despite that, geochronological data provided during this study indicate that Alpine Corsica results fro a complex polyphase evolution, being characterized by clear signature of both Alpine tectonics, at around 35 Ma, and Apennine tectonics, at around 25 Ma.Results provided in this paper contribute not only to the understanding of processes of subduction and mountain building, but also give important constraints for deciphering the Tethys-Alps and Alps-Apennine systems
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Harris, David Huw Mendus. « The structure, metamorphism and stratigraphy of Achill Island, Co Mayo, Ireland ». Thesis, Keele University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332352.
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Ni, Xinghua. « Late Paleozoic - Early Mesozoic tectonic evolution of the southwestern Central Asian Orogenic Belt : structural, metamorphic and magmatic evidence from the eastern Tianshan ». Electronic Thesis or Diss., Orléans, 2024. http://www.theses.fr/2024ORLE1043.
Texte intégralRésumé :
Les orogènes d'accrétion formées le long de marges convergentes se caractérisent par une longue évolution et sont les principaux sites de croissance continentale sur la Terre. Les phénomènes de convergence dans les orogènes d'accrétion impliquent des processus tectoniques complexes, tels que la subduction et le retrait de slabs, l'accrétion arc-arc/continent, et l'extension post-collisionnelle. Cependant, les processus orogéniques des anciennes orogènes sont plus compliqués en raison de l'importante érosion, nécessitant de connaissances approfondies sur la déformation, le métamorphisme et le magmatisme.La Ceinture Orogénique d'Asie Centrale (COAC) est un vaste système orogénique d'accrétion en Eurasie, formé par la subduction de l'Océan Paléo-asiatique et la convergence des cratons de Sibérie, Tarim-Chine du Nord, et Baltique pendant les Néoprotérozoïque et Paléozoïque supérieur, constituant une croûte juvénile, et offre un laboratoire naturel pour examiner la croissance continentale et les processus d'orogénèse. Le Tianshan oriental, situé au Sud-Ouest de la COAC, préserve des enregistrements de la subduction de la plaque océanique, de l'accrétion arc-arc/continent et de l'évolution post-collisionnelle. Des débats entravent notre compréhension de son évolution tectonique, y compris des questions liées aux socles crustaux, aux processus tectoniques, à la chronologie de l'amalgamation finale, et à l'évolution magmatique.Cette thèse présente une étude multi-échelle et multidisciplinaire de l'évolution tectono-métamorphique-magmatique du Tianshan oriental du Paléozoïque supérieur au Mésozoïque inférieur. En premier, l'histoire tectono-métamorphique du complexe métamorphique de Xiaopu dans Le Tianshan nord-est a été examinée avec des analyses structurales, métamorphiques et géochronologiques; Ensuite, des contraintes sur l'évolution tectono-magmatique du Tianshan nord-est et de l'Est du Junggar au Paléozoïque supérieur ont été établies basée sur les données géochronologiques, géochimiques et isotopiques; Enfin, l'évolution magmatique du Trias a été établie avec des investigations pétrographiques, géochronologiques, géochimiques et isotopiques de granitoïdes dans la région de Bogda et le Tianshan oriental. Les principaux résultats sont les suivants :1. Le socle du Tianshan nord-est et de l'Est de Junggar se compose principalement de croûte juvénile du Néoprotérozoïque au Phanérozoïque, probablement avec la présence d'un socle continental d'âge Méso-protérozoïque.2. L'accrétion arc-arc entre le Tianshan nord-est et l'Est de Junggar autour de 340-330 Ma a entraîné un raccourcissement et un épaississement crustal. Le retrait de la plaque océanique de Kangguer entre 330 et 310 Ma a provoqué une extension rétro-arc et un amincissement crustal dans la région de Bogda-Harlik, ainsi qu'un magmatisme lié à l'extension et un métamorphisme à haute température et basse pression.3. L'amalgamation finale du Tianshan oriental a eu lieu vers 300 Ma, entraînant un épaississement crustal dans le Tianshan nord-est et une accalmie magmatique dans les régions de l'Est de Junggar et de Kangguer-Yamansu, ainsi qu'une forte réduction de roches magmatiques intermédiaires dans la région de Bogda-Harlik-Dananhu.4. Après l'amalgamation, le Tianshan nord-est et l'Est de Junggar ont évolué vers un environnement post-orogénique pendant le Permien. L'extension et l'exhumation localisées, ainsi que la formation de roches magmatiques bimodales et de granitoïdes de type A généralisés, se sont produites en association avec la tectonique transcurrente régionale.5. Pendant le Trias, le magmatisme diversifié dans le Tianshan oriental résulte du remaniement de croûtes anciennes et juvéniles à des profondeurs et des températures variées, avec un apport du manteau dans un contexte intraplaqueAccretionary orogens forming along convergent margins are characterized by long-lived evolution and are the primary sites of continental growth on Earth. A typical convergence pattern of accretionary orogens involves complex tectonic processes, such as tectonic switching between advancing and retreating subduction, arc-arc/continent accretion, and post-collisional extension. However, elucidating the orogenic processes of ancient orogenic belts is more challenging due to extensive denudation, necessitating comprehensive knowledge on deformation, metamorphism, and magmatism.The Central Asian Orogenic Belt (CAOB) is a vast accretionary orogenic system within Eurasia, formed by the subduction of the Paleo-Asian Ocean (PAO) and the convergence of the Siberian, Tarim-North China, and Baltica (East European) cratons during the Neoproterozoic to late Paleozoic. It is considered as the largest Phanerozoic accretionary orogen containing significant juvenile crust, and offers a natural laboratory to examine continental growth and orogenic processes. The eastern Tianshan in the southwestern CAOB preserves crucial records of subduction, arc-arc/continent accretion and post-collisional evolution, providing unique insights into orogenic tectonics. Nonetheless, several debates still hinder our understanding of its tectonic evolution, including issues related to the crustal basements, detailed tectonic processes, timing of the final amalgamation, and magmatic evolution.This thesis presents a multi-scale and multi-disciplinary study of the tectonic-metamorphic-magmatic evolution of the eastern Tianshan during the late Paleozoic to early Mesozoic. Firstly, the tectono-metamorphic history of the Xiaopu Metamorphic Complex (XPC) in the eastern North Tianshan has been investigated through detailed structural, metamorphic, and geochronogical analyses. Secondly, spatial and temporal constraints on the late Paleozoic tectono-magmatic evolution of the eastern North Tianshan and East Junggar have been established based on geochronological, geochemical, and isotopic data sets from both new and previous studies. Thirdly, the Triassic magmatic evolution has been built up through detailed petrographic, geochronologic, geochemical, and isotopic investigations of newly identified Triassic granitoids from the Bogda region, alongside published data from the eastern Tianshan. The main results lead to the following conclusions: 1.The basement of the eastern North Tianshan and East Junggar regions primarily comprises Neoproterozoic to Phanerozoic juvenile crust, likely with a presence of a Mesoproterozoic continental basement similar to that of the Central Tianshan Block in the Kangguer-Yamansu area. 2.Arc-arc accretion between the eastern North Tianshan and East Junggar around 340-330 Ma resulted in crustal shortening and thickening. The roll-back of the Kangguer oceanic slab between 330 and 310 Ma caused back-arc extension and crustal thinning in the Bogda-Harlik region, along with extension-related magmatism and high temperature and low pressure (HT-LP) metamorphism.3.The final amalgamation of the eastern Tianshan occurred around 300 Ma, leading to crustal thickening in the eastern North Tianshan and a magmatic lull in the East Junggar and Kangguer-Yamansu regions, as well as a sharp reduction in intermediate magmatic rocks in the Bogda-Harlik-Dananhu region.4.Following the amalgamation, the eastern North Tianshan and East Junggar evolved into a post-orogenic setting during the Permian. Localized crustal extension and exhumation, along with the formation of bimodal magmatic rocks and widespread A-type granitoids, likely occurred in association with regional transcurrent tectonics.5.During the Triassic, the magmatism diversity in the eastern Tianshan resulted from the reworking of both ancient and juvenile crust at varying depths and temperatures, with some mantle input in an intraplate setting
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Page, Laurence M. (Laurence Michael). « Structure, metamorphism, and geochronology of the Singis-Nikkaluokta region, Arctic Scandinavian Caledonides ». Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/60420.
Texte intégralRésumé :
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1990.1 folded map in pocket.
Includes bibliographical references (leaves 190-196).
by Laurence M. Page.
Ph.D.
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Tilke, Peter Gerhard. « Caledonian structure, metamorphism, geochronology, and tectonics of the Sitas-Singis area, Sweden ». Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/40348.
Texte intégralRésumé :
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1987.MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN.
8 maps in pocket of volume 1.
Bibliography: leaves 215-223.
by Peter Gerhard Tilke.
Ph.D.
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Garwin, Stephen Lee. « Structure and metamorphism in the Niagara Peak area, western Cariboo Mountains, British Columbia ». Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26259.
Texte intégralRésumé :
A more than 2000 m thick sequence of Hadrynian to Paleozoic Snowshoe Group metasedimentary rocks of the Omineca Belt (OMB) is exposed near Niagara Peak in the western Cariboo Mountains, central British Columbia. This package contains the northern extremity of the Shuswap Metamorphic Complex and lies 30 km northeast of the accretionary boundary with Intermontane Belt (IMB) Mesozoic sedimentary and volcanic rocks (Quesnellia Terrane) and Upper Paleozoic (?) ophiolitic and sedimentary rocks (Slide Mountain Terrane).
Four phases of folding (D₁-D₄) are recognized. D₁ consists of isoclinal folds and transposed compositional layering. D₂ commonly forms southwest verging, open to close folds with subhorizontal axes and moderately northeast dipping axial surfaces. In the eastern part of the area, divergent fanning of D₂ axial surfaces and a reversal of vergence direction occur about a map-scale synform characterized by greater strain, bimodal fold style and a locally penetrative axial planar cleavage. D₃ and D₄ form orthogonal upright open buckles with respective northwest and northeast trending axes. Steeply dipping normal and minor reverse faults crosscut all fold structures, displaying minor offsets.
Prograde regional metamorphism reached greenschist grade late in D₁. Staurolite and kyanite growth accompanied D₂, followed by postkinematic sillimanite generation under conditions of approximately 635° C and 5 kb. D₃ associated sericite-chlorite retrogression of porphyroblasts occurs in sub-sillimanite grade rocks in the western part of the area. Synmetamorphic veins represent polyepisodic hydraulic fracture development during progressive dewatering of a sedimentary pile by prograde metamorphism.
Eastward obduction of Quesnellia and Slide Mountain Terranes onto theOmineca Belt took place in the Middle Jurassic. Shortly following this event, the IMB-OMB tectonic suture was deformed, forming map-scale folds of cuspate/lobate geometry.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
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Large, David John. « An investigation of metamorphism, structure and fluid flow in the Trois Seigneurs Massif ». Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241080.
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Grütter, Hermanus Smalberger. « Structural and metamorphic studies on Ios, Cyclades, Greece ». Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282815.
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Salt, Christopher James. « Metamorphic and structural history of Glenelg, NW Scotland ». Thesis, University of Edinburgh, 1995. http://hdl.handle.net/1842/11358.
Texte intégralRésumé :
The Glenelg peninsular in NW Scotland contains Lewisian type rocks occurring east of the Moine thrust that have been metamorphosed and deformed along with the Moine rocks. These Lewisian rocks can be split into two facies, the Eastern Lewisian and the Western Lewisian, always separated by a thin strip of highly deformed Moine rocks. The Western Lewisian contains no recognisable meta-sediments, only a variety of meta-igneous rocks. Eclogite is rare, only occurring at one locality as pods within otherwise deformed amphibolite facies rocks. These eclogites exhibit broadly similar textures to the Eastern Lewisian eclogites, but have a slightly different chemistry, being more Si rich and Ca poor. They are formed under similar conditions of about 760°C, 15 Kb, but only one metamorphic event has been distinguished. Many of the amphibolites of the Western Lewisian have similar textures and chemistry as partly retrogressed Western Lewisian eclogite. These rocks were deformed to produce a weak fabric prior to the intrusion of further basic material that is texturally and chemically different to the eclogites. All of these rocks were then deformed and metamorphosed by the syn-Moine deformation as outlined above for the Eastern Lewisian. It is suggested that the Eastern and Western Lewisian rocks share a common history of initial high-pressure metamorphism, then the intrusion of granitic melt prior to further high pressure metamorphism. This was followed by deformation and partial retrogression before the intrusion of basic and ultrabasic dykes. The Lewisian rocks were then exhumed and the Moine rocks deposited onto them prior to further deformation and metamorphism. Radiometric dating suggests that the high pressure metamorphism occurred at approximately 1050 Ma (Grenville), but field and petrographic evidence suggests that the Lewisian rocks have undergone a similar history to the Scourian rocks of the main Lewisian outcrop and that Grenville ages for the rocks date initial syn- Moine metamorphism.
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Piraquive, Alejandro. « Cadre structurel, déformations et exhumation des Schistes du Santa Marta : accumulation et histoire de déformation d'un terrain caraïbe au nord de la Sierra Nevada de Santa Marta ». Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAU019/document.
Texte intégralRésumé :
La Sierra Nevada de Santa Marta (SNSM) est peut-être Le massif de la croûte terrestre le plus complexe trouvé dans les Andes du Nord. Sa situation unique comme un massif triangulaire isolé segmenté de la continuité de 7000 km de long Andes montagne comme la dernière position devant les domaines de la plaque des Caraïbes plus jeune, place la SNSM comme une île séparée de toutes les chaînes de montagnes environnantes de la marge continentale. Un relief important caractérise cette montagne atteint l'altitude la plus élevée dans le domaine des Caraïbes entière à 5750 m, et de définir, la SNSM comme le plus grand chaîne de montagnes côtières dans le monde. La SNSM est une caractéristique géologique unique un remarquable que les récifs coralliens Etreintes biodiversité de SES dans les forêts tropicales qui passent d'auge fortement végétalisées la mer des Caraïbes, les forêts de haute nuage, et bruyères, jusqu'à ce que, son magnifique sommet couronné par les glaciers.Par sa position sur la marge nord - ouest de l' Amérique du Sud l'étude de la SNSM donne l'occasion de résoudre des questions importantes sur l'évolution des cycles super-continentales depuis les temps Grenvilliens par l'orogenèse Neoproterozoic Pan-Africain, l'orogenèse Paléozoïque tardif Ouachitan-Appalaches cela a conduit Pangaea assemblée, et Trias Pangaea débâcle suivie par la Rift Atlantique Jurassique centrale et plus récemment par le début de la plaque des Caraïbes accrétion / subduction depuis le Crétacé tardif contre le nord - ouest en Amérique du Sud.Je tenté de démêler l'histoire géologique de la Sierra Nevada de Santa Marta Massif utilisant les plus avancées en géochronologiques, thermochronologiques, géochimiques et isotopiques techniques qui a permis de recueillir une quantité importante de nouvelles données à ajouter à la base de données existante sur la SNSM. Nos résultats comprennent une carte géologique réévaluée 1: 25000, qui comprend la définition de quatre nouvelles unités stratigraphiques, Accompagné de deux sections crustales sur 320 km de longueur ce disséquer le massif, et 8 sections parallèles à l'angle nord - ouest de le ceinture métamorphique de la SNSM. L'ensemble des données géochimiques et isotopiques comprend: i) 17 roches ignées et métamorphiques et six échantillons détritiques datés par ablation laser induite par couplage plasma spectrométrie de masse (LA-ICP-MS) U-Pb zircon géochronologie qui a abouti à 2790 nouvelles dates et in-situ analyse des oligo - élément, ii) 16 roches ignées et métamorphiques qui a donné 31 nouveaux âges thermochronometriques: 12 âgés du traces de fission en zircon 11 âges du traces de fission des apatites et 7 âges (U-Th) / He dans les apatites, iii) Géochimie de la roche entière à partir de 10 échantillons et iv) analyses à la microsonde chimie minérale et cartes x-ray de quatre échantillons a donné aux grenats zonées et péritectiques. Elles ont été données acquises à partir des unités du complex métamorphique nord - ouest du massif SNSM. Avec ces données, nous enquêté i) Les unités sont conformes à la SNSM ce ceintures métamorphiques, de leurs relations chronologiques et stratigraphiques du Précambrien à l'Eocène; ii) Le laps de temps et les conditions P-T du l’événement métamorphique Paléozoïque tardif à Mésozoïque précoce (chapitre 1), iii) Le moment de l'activité ignée, accrétion et l'exhumation des terranes océaniques et continentales au cours du Crétacé tardif à la fin du Miocène. iv) Un mécanisme pour expliquer comment l’exhumation a eu lieu sous un régime collisionnel influencé par un processus climatique à l'érosion et des gradients thermiques élevées (chapitre 2); v) Les processus tardifs de la dénudation et la sédimentation contrôlées par la tectonique dans deux bassins marginaux depuis le Miocène précoce dans le diminution des taux d'érosion et gradients thermiques (chapitre 3)The Sierra Nevada de Santa Marta (SNSM) is perhaps the most complex crustal massif found in the Northern Andes. Its unique situation as an isolated triangular massif segmented from the continuity of the 7000 km long Andes as the last standing mountain before the domains of the younger Caribbean plate, places the SNSM as an island separated from all surrounding mountain ranges of the continental margin. A prominent relief characterizes this mountain reaching the highest altitude in the entire Caribbean realm at 5750 m, and defines, the SNSM as the highest coastal mountain range in the world. For this reason the SNSM is a unique geological feature that embraces an outstanding biodiversity from its coral reefs in the Caribbean Sea passing trough heavily vegetated tropical rainforests, high cloud forests, and moorlands, until its magnificent summit capped by glaciers.By its position on the northwestern margin of South America the study of the SNSM provides the opportunity to resolve important questions on the evolution of super-continental cycles since Grenvillian times through the Neoproterozoic Pan-African orogeny, the Late Paleozoic Ouachitan-Appalachian orogeny that led to Pangæa assembly, and Triassic Pangæa break-up followed by the Jurassic Central Atlantic Rift and more recently by the start of the Caribbean plate accretion/subduction since the Late Cretaceous against northwestern South America.In this investigation I attempt to unravel the geological history of the Sierra Nevada de Santa Marta Massif using geochronological, thermochronological geochemical and isotopic techniques that allowed to gather a significant amount of new data to add to the existent database on the SNSM.Our results include a reevaluated geological map 1:25000, in which I define 4 new stratigraphic units, accompanied by two crustal-scale cross sections of 320 km length that dissect the massif, and 8 parallel cross sections at the NW corner of the SNSM metamorphic belt. The geochemical and isotopic dataset includes: i) 17 igneous and metamorphic rocks and 6 detrital samples dated by laser-ablation induced-coupled-plasma mass-spectrometry (LA-ICP-MS), U-Pb zircon geochronology that resulted in 2790 new dates and in-situ trace element analyses, ii) 16 igneous and metamorphic rocks that yielded 31 new thermochronometric ages as follows: 12 zircon fission track ages, 11 Apatite fission track ages and 7 (U-Th)/He in apatite ages, iii) Whole rock geochemistry from 10 samples and iv) Microprobe mineral chemistry in spot analyses and x-ray maps from 4 samples that yielded zoned and peritectic garnet. These data were acquired from the units of the northwestern metamorphic suite of the SNSM massif. With these data we investigated i) The units that conform the SNSM metamorphic belts, their chronological and stratigraphic relationships from the Precambrian to the Eocene; ii) The time span and P-T conditions of a Late Paleozoic-Early Mezosoic metamorphic event (Chapter 1), iii) The timing of igneous activity accretion and exhumation of oceanic and continental terranes during the Late Cretaceous to late Miocene. iv) A mechanism for explaining how this exhumation occurred under a collisional regime by a climate influenced process at elevated erosion and thermal gradients (Chapter 2); v) The late processes of denudation and sedimentation controlled by tectonics in two marginal basins since the early Miocene under decreased erosion rates and thermal gradients (Chapter 3)
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Thigpen, James Ryan. « Vorticity of Flow, Deformation Temperatures, and Strain Symmetry of the Moine Thrust Zone, NW Scotland : Constraining the Kinematic and Thermal Evolution of a Collisional Orogenic System ». Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/28228.
Texte intégralRésumé :
Examination of deformation temperature, flow vorticity, and strain symmetry in the Loch Eriboll, Loch More, and Assynt regions of the Moine thrust zone (MTZ) in northwest Scotland allows quantitative kinematic and thermal characterization of a crustal-scale shear zone at the base of the Scandian (435-425 Ma) orogenic wedge. Quartz crystal fabrics, kinematic vorticity (Wm), and strain estimates from the ductile thrust sheets in this region are used to determine how pure and simple shear components of deformation are partitioned, and indicate that these processes may be thermally, structurally, and lithologically dependent. Vorticity analysis of samples collected along strike in the MTZ and overlying Moine nappe indicate that Scandian thrusting and deformation involved a considerable pure shear component. Integrated strain and vorticity estimates indicate that significant sub-vertical foliation normal shortening has occurred as nappe stacking progressed. Along strike Wm variation could not be directly correlated with changes in footwall structural architecture, lithology, deformation temperatures, or structural depth and are thus interpreted to reflect local variability driven by a complex interplay of these and possibly other factors. Quartz c- and a-axis fabrics indicate that deformation in the footwall of the Moine thrust involved plane strain to general flattening strain with only a minor rotational (non-coaxial) component. In contrast, deformation in the Moine nappe was strongly non-coaxial, as indicated by asymmetric single girdle c-axis fabrics. Quartz c-axis opening angles and microstructures suggest that deformation temperatures increase from north to south and from structurally lower to structurally higher levels in the footwall to the Moine thrust. Vertical ductile thinning must be accommodated by either volume loss or extrusion of material towards the synorogenic topographic surface. Extrusion towards the synorogenic topographic surface implies a causal link between upper and lower crustal processes, with significant implications for the kinematic, geometric, and kinetic (deformation rates) evolution of the Scandian orogenic wedge. New thermobarometric and deformation temperature estimates are combined with structural and kinematic investigations to characterize the thermal structure of the Moine, Ben Hope, and related nappes. At the leading edge of the Moine thrust, subhedral garnets with prograde compositional growth zoning yield peak temperatures (grt-bio) of 440-492 °C at 4.5-6.0 kbars from Creagan Meall Horn to northern Assynt. Three samples collected at similar structural positions along the leading edge of the Moine nappe yield deformation temperatures of 420-460 °C, as determined from quartz c-axis opening angles. At the structurally highest position in the Moine nappe, garnet prograde compositional zoning profiles are preserved and samples yields P-T estimates of 565-571 °C (grt-bio) and 4.5-5.1 kbar (GRAIL barometer, minimum pressure due to absence of Al2SiO5 phase). Quartz c-axis fabrics of samples collected at similar structural positions yield deformation temperature estimates of 490-565 °C. In the structurally higher Ben Hope nappe, two phases of prograde compositional growth zoning are preserved in garnet bearing amphibolite near Portvasgo. The later outer garnet rim records P-T conditions of 655-672 °C at 3.9-5.1 kbars. The inverted metamorphic sequence from the Moine to the Naver thrust is mostly intact and is interpreted to be Scandian (435-420 Ma) in age. It is likely that the formation of this inverted sequence is due to a combination of progressive accretion of successively lower grade thrust sheets onto the base of the Scandian wedge and heating of the Moine and Ben Hope nappes from above by the relatively higher temperature migmatites of the Naver thrust. Vertical ductile thinning, in conjunction with erosion and normal faulting, likely led to rapid exhumation of the Scandian nappe pile and in turn preserved the inverted metamorphic sequence.Ph. D.
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Chan, Heung-ngai. « Igneous and metamorphic rocks from SW Cyprus and NW Syria evidence for Cretaceous microplate collision and subsequent tectonic events in the Eastern Mediterranean / ». Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B30711940.
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Trainor, Robert J. « Structure/kinematic and metamorphic analysis of the mesoproterozoic Novillo Gneiss, Tamaulipas, Mexico ». Ohio : Ohio University, 2010. http://www.ohiolink.edu/etd/view.cgi?ohiou1268932865.
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Clemons, Kristopher M. « PETROFABRIC AND GEOCHEMICAL ANALYSIS OF THE GREAT SMOKY -- SNOWBIRD GROUP CONTACT, WESTERN BLUE RIDGE, NORTH CAROLINA AND TENNESSEE ». Lexington, Ky. : [University of Kentucky Libraries], 2006. http://lib.uky.edu/ETD/ukygeol2006t00490/thesis.pdf.
Texte intégralRésumé :
Thesis (M.S.)--University of Kentucky, 2006.Title from document title page (viewed on November 1, 2006). Document formatted into pages; contains: vii, 95 p. : ill. (some col.), maps. Includes abstract and vita. Includes bibliographical references (p. 91-94).
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Druguet, Elena. « The structure of the NE Cap de Creus peninsula relationships with metamorphism and magmatism ». Doctoral thesis, Universitat Autònoma de Barcelona, 1997. http://hdl.handle.net/10803/3444.
Texte intégralRésumé :
Este estudio esta centrado en la tectónica de los dominios mas profundos que afloran en el sector septentrional de la península del Cap de Creus, así como en el metamorfismo y el magmatismo asociados. La península del Cap de Creus constituye el afloramiento mas oriental del zócalo paleozoico que conforma la zona axial de los Pirineos, en la cual las foliaciones penetrativas, el metamorfismo y el magmatismo son de edad hercinica. Las rocas que afloran en el area objeto de estudio corresponden a una secuencia metasedimentaria que contiene intercalaciones esporádicas de rocas igneas metamorfizadas. La presencia de un gradiente metamórfico, con grado creciente hacia el norte evidencia un metamorfismo regional progrado de baja presión, iniciado durante los episodios deformativos tempranos, que se manifiesta por una zonación que abarca desde la zona de la clorita-moscovita al sur, hasta la zona de la silimanita-feldespato potásico, al norte. Localmente, en los dominios de grado medio y alto, aparecen areas migmatiticas junto con granitoides calco-alcalinos, emplazados secuencialmente desde los términos más básicos hasta los más ácidos. Un enjambre de diques de pegmatitas aparece en los dominios anatecticos y perianatecticos hasta la zona de la cordierita-andalucita. El metamorfismo retrógrado superpone heterogeneamente a la zonación prograda y es especialmente manifiesto a lo largo de las bandas miloniticas. Las estructuras tectónicas polifásicas se han interpretado como resultado de una historia deformacional progresiva, con una manifiesta continuidad desde los eventos en condiciones metamórficas progradas hasta aquellos desarrollados en condiciones retrogradas. A efectos de exponer la evolución tectónica se han distinguido tres episodios principales. El episodio temprano (d1) genera una foliación penetrativa (s1), presumiblemente en disposición original sub-horizontal. A continuación, una secuencia de episodios deformacionales da lugar a una sucesión de estructuras fuertemente inclinadas. Cada episodio es inhomogeneo en el espacio y esta caracterizado por una deformación progresiva no-coaxial, dando lugar a la formación de una compleja configuración estructural. El episodio d2 genera pliegues de trazado ne-sw que afectan en condiciones progradas a la foliación s1. Los gradientes ligados a este plegamiento definen una zonación estructural, con dominios de débil e intensa deformación y una geometría análoga a la de zonas de cizalla. Las zonas de mayor deformación se localizan preferentemente en el sector septentrional y se halla asociada a procesos de migmatización y de emplazamiento de granitoides. Un estadio transicional entre d2 y d3 (denominado d2-3) se caracteriza por el desarrollo de pliegues sub-verticales de dirección E-W. Este estadio deformacional se situa alrededor del climax metamorfico y presenta una gradación hasta situaciones de retrogradación a temperatura elevada en el norte (en donde el enjambre de pegmatitas se halla emplazado sintectonicamente). Este mismo estadio deformacional presenta condiciones claramente retrogradas en el centro y sur. La progresión de la deformación en condiciones retrógradas genera las estructuras d3, de direccion NW-SE, que en el sur conforman una faja de pliegues y en el norte una faja milonitica sobre las rocas de mayor cristalinidad. Esta circunstancia da lugar a una segunda zonación estructural. Las relaciones entre las estructuras de temperatura elevada (d2 y d2-3) en los metasedimentos y las estructuras de los granitoides y pegmatitas, evidencian el sincronismo entre los procesos deformativos y magmáticos. Además, a pesar de la manifiesta complejidad de las relaciones entre geometría y cinemática, el análisis de la deformación de estas estructuras muestra que la deformación responde a una situación de tectonica transpresiva, en la que estan implicadas una extensión subvertical y un acortamiento general NNW-SSE con un componente direccional dextro.
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Williams, Mathew Philipps. « The structure and metamorphism of the northern margin of the Indian plate, north Pakistan ». Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46609.
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Schwarz, Steven H. « Structural, metamorphic and tectonic studies in Central Gagnon Terrane, Grenville Province / ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0034/MQ47431.pdf.
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Grills, John Andrew. « Chemical, metamorphic and structural relationships of certain sheared metadolerites ». Thesis, Queen's University Belfast, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484277.
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Poulton, Rachel Jane. « The structural and metamorphic evolution of Sifnos, Cyclades, Greece ». Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243058.
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Goren, Keith Daniel Joseph. « Optimization of the metamorphic development process via the genetic algorithm / ». Full text available online, 2008. http://www.lib.rowan.edu/find/theses.
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Gichile, Samuel. « Structure, metamorphism and tectonic setting of a gneissic terrane, the Sagan Afelata area, southern Ethiopia ». Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7947.
Texte intégralRésumé :
The Sagan-Afelata area, which extends east approximately 100 km from the Main Ethiopian Rift towards the Adola gold fields, is underlain by high-grade rocks, dominantly biotite and quartzofeldspathic gneiss. The gneissic rocks are characteristically of K-rich mineralogy and appear to form a Proterozoic supracrustal sequence rather than Archean basement as thought earlier. The gneissic rocks were subjected to at least three distinct phases of deformation. The first, D$\sb1$, to which probably several generations of structures are attributed, formed migmatitic layering then isoclinal folds that transposed the layers parallel to flat-lying regional foliation (S$\sb1$), during amphibolite to granulite facies metamorphism. The second, D$\sb2$, formed upright folds in S$\sb1$ and parallel layers with subhorizontal NNW to NNE trending axes, accompanied by amphibolite facies metamorphism that overprinted most rocks. D$\sb3$, resulted in local E-W trending, open, upright folds that are confined to the eastern part of the area. (Abstract shortened by UMI.)
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Bateman, Neil. « Computer modelling and structural studies of phyllosilicate transformation during diagenesis and low grade metamorphism ». Thesis, Keele University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273025.
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Leonard, Richard. « Variable structural style, stratigraphy, total strain and metamorphism adjacent to the Purcell thrust, near Blackman Creek, B.C ». Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63282.
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Grimes, Stephen Whiteford. « The Grenville orogeny in West Texas : structure, kinematics, metamorphism and depositional environment of the Carrizo Mountain Group / ». Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
Texte intégralRésumé :
Thesis (Ph. D.)--University of Texas at Austin, 1999.Vita. Three folded plates in pocket. Includes bibliographical references (leaves 359-371). Available also in a digital version from Dissertation Abstracts.
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Fitz-Gerald, Dudley Braden. « Evidence for an Archean Himalayan-style orogenic event in the northern Teton Range, Wyoming ». Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1798480821&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Poust, Benjamin David. « X-ray scatter based metrologies for the development of metamorphic semiconductor device structures ». Diss., Restricted to subscribing institutions, 2007. http://proquest.umi.com/pqdweb?did=1320974691&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Leung, Wing-hang Allen. « Metamorphism of the Helanshan Complex implications for the tectonic evolution of the Khondalite Belt, North China Craton / ». Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B41634160.
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Venance, Katherine Elizabeth Carleton University Dissertation Earth Sciences. « Low pressure metamorphism of the Torp Lake area, Northern Hood River belt, Slave Structural Province ». Ottawa, 1994.
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Sigler, Joshua T. « The metamorphic and structural evolution of the Davis Peak area, northern Park Range, Colorado ». Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1798480831&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
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Christy, Andrew Gregor. « The structure and stability of sapphirine in relation to its metamorphic environment ». Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278298.
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Jessup, Micah John. « Kinematic Evolution, Metamorphism and Exhumation of the Greater Himalayan Sequence, Mount Everest Massif, Tibet/Nepal ». Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/37678.
Texte intégralRésumé :
The Himalayan orogen provides an incredible natural laboratory to test models for continent-continent collision. The highest peaks of the Himalayas are composed of the Greater Himalayan Sequence (GHS), which is bound by a north-dipping low angle detachment fault above (South Tibetan detachment; STD) and by a thrust fault below (Main Central thrust; MCT). Assuming simultaneous movement on these features, the GHS can be modeled as a southward extruding wedge or channel. Channel flow models describe the coupling between mid-crustal flow, driven by gradients in lithostatic pressure between the Tibetan Plateau and the Indian plate, and focused denudation on the range front. Although the general geometry and shear sense criteria for these bounding shear zones has been documented, prior to this investigation, relatively few attempts had been made to quantify the spatial and temporal variation in flow path history for rocks from an exhumed section of the proposed mid-crustal channel. Results from this investigation demonstrate that mid-crustal flow at high deformation temperatures was distributed throughout the proposed channel. As these rocks began to exhume to shallower crustal conditions and therefore lower temperatures, deformation began to become partitioned away from the core of the channel and into the bounding shear zones. Based on these results a new method (Rigid Grain Net) to measure the relative contributions of pure and simple shear (vorticity) is proposed. Detailed thermobarometric analysis was conducted on rocks from the highest structural level in the Khumbu region, Nepal to construct pressure-temperature-time-deformation paths during the tectonic evolution of the GHS between ~32-16 Ma. Another aspect of the project suggests that the most active feature of the region is the N-S trending Ama Drime Massif (ADM). By combining new structural interpretation with existing remote sensing data this investigation proposes that the ADM is being exhumed during extension that is coupled with denudation in the trans-Himalayan Arun River gorge. Together these data provide important insights into the dynamic links between regional-scale climate and crustal-scale tectonics.Ph. D.
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Norquay, Lawrence I. « Structural and metamorphic evolution of the North Star Lake area, Manitoba ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23443.pdf.
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Van, Bosse Jacqueline Yvonne. « Metamorphism and alteration in the thermal auerole of the McGerrigle Mountains pluton, Gaspé, Québec ». Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66061.
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Voorhees, Jacob Isaac. « Structure of Collisional Metamorphism, Soft-Sediment Deformation, and Low-Angle Normal Faulting in the Beaver Dam Mountains ». BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8698.
Texte intégralRésumé :
Precambrian metamorphic rocks in the Beaver Dam Mountains display asymmetric, isoclinal folds with consistent fold axes plunging to the NW. These folds are parasitic and have a recursive nature that occurs on wavelengths from centimeters to perhaps kilometers as part of a NW-SE striking shear zone. The vergence of the folds indicates oblique shearing with a transport direction plunging 29° to the south. This shear zone may be associated with the collision of Yavapai Province island arcs with Laurentia. Structurally overlying, and adjacent to the metamorphic rocks are allochthonous and attenuated Mississippian limestone blocks and other strata debated to be either the result of mega-landsliding or fragments of the hanging wall rocks above a low-angle normal fault. We document previously unreported cataclastic damage zones tens of meters thick, an anastomosing zone of greenschist facies alteration hundreds of meters thick, and polished low-angle fault surfaces beneath these blocks. Other observations previously used to support a mega-landslide hypothesis are blocks of Redwall Limestone structurally overlying what was interpreted as Tertiary conglomerate. However, this contact is depositional, and the conglomerate is likely a sedimentary breccia facies of the Mississippian Redwall Limestone which is documented in several locations within the region. Additionally, some of the deformation and attenuation that was wrongly attributed to mega-landsliding or low-angle normal faulting is due to previously undocumented soft-sediment deformation. This deformation was gravity driven and accommodated by ductile granular flow, resulting in recumbent folds within the Mississippian Redwall Limestone and a prominent non-brittle detachment surface between the Redwall Limestone and the Cambrian Bonanza King Formation at Castle Cliff. This detachment was previously interpreted as the Castle Cliff Detachment, a low-angle normal fault, or as the slip surface of a landslide.
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Walker, Thomas Bradley. « BEDROCK GEOLOGY AND TECTONIC EVOLUTION OF THE WESTERN CENTRAL MAINE ZONE, SOUTH CENTRAL MASSACHUSETTS ». UKnowledge, 2011. http://uknowledge.uky.edu/ees_etds/1.
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Bedrock geology of the East Brookfield quadrangle (EBQ), based on new 1:24000 scale mapping, consists of an interfolded sequence of Rangeley Fm. and Paxton Fm. metasediments, intruded by Early Mississippian tonalitic to granitic orthogneisses and underlain in the western half by folded orthogneisses of unknown age. Pervasive flattening strains have created planar, generally NNE-SSW striking and consistent moderately west dipping foliations. Generally strike-parallel stretching lineations and boudinage structures, with rarer dip parallel stretching lineations, reflect extrusion of CMZ metasediments and orthogneisses with a flattening component. Mapping in the EBQ demonstrates that a transition between deformational mechanisms of the southern Central Maine Zone is located there. Evidence for previously mapped faults was not observed during mapping. Alternatively, map scale folds terminating in the East Brookfield quadrangle likely accommodated the across-strike shortening and repetition of lithologic units of the CMZ during Acadian orogenesis. Aeromagnetic patterns and outcrop data approximate a map scale, east-verging and west-dipping, shallowly north-plunging isoclinal fold consisting of interlayered mafic and felsic gneisses. Constrictional and flattening strains documented in the deformation features of the East Brookfield quadrangle suggest that it is located on/near the eastern margin of the zone of transpression approximated by the Bronson Hill gneiss domes. Outcrop- to meter-scale folds with hinge axes sub-parallel to parallel with regional lineations suggest constrictional deformation in a transpressional regime. Deformation features associated with map-scale folding, extrusion/extension, and flattening of CMZ lithologies in the East Brookfield quadrangle support a regime of transpressional deformation caused by oblique convergence of Avalonian terrane with Laurentia. U-Pb ages and outcrop structural relationships suggest that regional flattening and folding was syn- to late-orogenic in nature and Carboniferous or younger in age. All previous structural fabrics are transposed by late regional flattening. Lithologies of the East Brookfield quadrangle exemplify the nature of the Acadian granulite-facies high, displaying a peak metamorphic assemblage of Crd + Grt + Sil + Kfs that has undergone retrograde reactions to produce Bt + Sil. Retrograde metamorphism and deformation occurred during strike-parallel extrusion of CMZ lithologies. Retrograde minerals define kinematic/shear sense indicators that record an overall top to the NNE or ENE asymmetry on vertical faces and dextral west side north on horizontal surfaces. Progressive deformation of CMZ lithologies through transpressional mechanisms is proposed as an alternative to the sequential development of Acadian deformational features in three separate stages.