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

Effects of Interdependency in the Xinjiang-Central Asian Region

McMillan, Ann Mary, n/a January 2004 (has links)
The past decade has seen a transformation in the relationships among states in the Xinjiang-Central Asian region. The thesis is an analysis of this relationship, a relationship primarily built on economic and strategic interdependency. Within the thesis, the basis of the relationship is established; the extent of the relationship is ascertained, and the impact of this relationship is evaluated. The thesis differs from previous studies of this area in several ways. The most significant is that a group of Central Asian states and an autonomous region of China have formed into a unit of economic interdependency, which needs to be assessed as a group rather than as individual entities. Much of previous and recent scholarship tends to focus on issues within a particular country or part of a country, such as the Xinjiang Uygur Autonomous Region of the People's Republic of China. However, it is my contention that this is not an adequate representation of what is occurring in the region today. The focus needs to be widened to take into account the dynamics of this interdependent relationship which consists of the Xinjiang Uygur Autonomous Region and several of the former Soviet Union states, primarily Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan. All of these states with the exception of Uzbekistan are contiguous with Xinjiang. This relationship of interdependency has reached a level sufficient to influence decisions taken by governments within the region, and a prime factor of this has been the suppression of secessionist movements, principally Uygur separatist movements, among the Uygur diaspora residing in neighbouring states. Another highly relevant issue the thesis evaluates is sources of tension within the Xinjiang-Central Asian region and the impact these tensions have on the interdependency relationship. An assessment is made as to whether because of this interdependency, the sources of tension may not be adequately addressed by the respective governments to the satisfaction of the general populace. This is seen as due to the individual governments' hesitation to upset China by addressing such matters as border demarcation and transboundary water diversion between China and neighbouring states. An outcome of this scenario may be that many of the tensions are left to simmer and therefore bode ill for future stability in the region. Fundamentally, the thesis argues that the matters raised in the previous paragraphs need to be assessed on the basis of an ongoing relationship of interdependency encompassing Xinjiang and several neighbouring Central Asian states. The overlapping of multiple sources of commonality such as geography, ethnicity, culture, religion, economics and strategic matters, dictates that we should not assess issues on a country-by-country basis. Rather, it is necessary to consider the region as a whole, taking into account the prevailing conditions emanating from this relationship of economic and strategic interdependency.
2

Fold-and-thrust belt deformation of the Hongliuhe Group: a Permian tectonic closure record of the Central Asian Orogenic Belt, NW China

Cleven, Nathan January 2011 (has links)
The Early Permian strata of the Hongliuhe Group, NW China, experienced a thin-skinned fold-and-thrust belt style of deformation that recorded the final stages of amalgamation of the Beishan orogenic collage, a part of the Central Asian Orogenic Belt. The Hongliuhe Group was syn-orogenically deposited on an undetermined foreland, with the Mazongshan arc terrane acting as the hinterland. In this study results from detailed mapping combined with a regional analysis elucidate involvement of a northward-dipping subduction system with the collision. Well-preserved fold-and-thrust belt style deformation mapped in the upper stratigraphy of the Hongliuhe Group exhibits dominantly south-southeast verging structure, including shear folding, low-angle thrust ramping, imbrication and duplexing. Restoration of a portion of a mapped outcrop-scale cross-section estimates the accommodation of a minimum of 24% shortening. Lower stratigraphy shows discrete, steeper, north-over-south dip-slip ductile shear zones that bound packages of less deformed Hongliuhe Group strata. Fault displacement is considered to have been prolonged enough to juxtapose basal formations in northerly hangingwalls against upper formations in southerly footwalls. Faulting is closely associated with the creation of large-scale brittle-ductile eye-fold structures that are postulated to be sheath folds. The most examined and mapped structure, 16km wide, is a synclinal structure with axes plunging steeply towards its center. The ellipticity of the exposed bedding traces increases towards the center of the eye-fold, implying a structural relationship with metamorphic shear zones. Except for large-scale folding, the bulk of its strata remain relatively undeformed and have preserved primary soft-sediment deformation structures indicating younging towards the center on both limbs of the synclinal structure. Stratigraphic reconstruction of the Hongliuhe Group that considers the significant faulting shows that the Group's basal conglomerates unconformably overlie a Late-Carboniferous volcanic assemblage. The clast lithotypes of the conglomeratic successions change from polymictic metamorphic rocks at the base to monomictic granitoid clasts mid-section, showing the gradual unroofing sequence of the provenance. The stratigraphic reconstruction shows a general fining upward sequence, transitioning from terrestrial to nearshore marine depositional environments that, and in conjunction with the conglomeratic successions, suggests that the tectonic setting for deposition of the Hongliuhe Group is a foreland basin. Considering the deformation styles reported in this study, the Hongliuhe Group is interpreted to be a foreland fold-and-thrust belt. Stratigraphic reconstruction of the Hongliuhe Group that considers the significant faulting shows that the Group’s basal conglomerates unconformably overlie a Late Carboniferous volcanic assemblage. The clast lithotypes of the conglomeratic successions change from polymictic metamorphic rocks at the base to monomictic granitoid mid-section, showing the gradual unroofing sequence of the provenance. The stratigraphic reconstruction shows a general fining upward sequence through nearshore depositional environments that, and in conjunction with the conglomeratic successions, give interpretation that the tectonic setting for deposition of the Hongliuhe Group is a foreland basin. Considering the deformation styles reported in this study the Hongliuhe Group is interpreted to be a foreland fold-and-thrust belt.
3

Fold-and-thrust belt deformation of the Hongliuhe Group: a Permian tectonic closure record of the Central Asian Orogenic Belt, NW China

Cleven, Nathan January 2011 (has links)
The Early Permian strata of the Hongliuhe Group, NW China, experienced a thin-skinned fold-and-thrust belt style of deformation that recorded the final stages of amalgamation of the Beishan orogenic collage, a part of the Central Asian Orogenic Belt. The Hongliuhe Group was syn-orogenically deposited on an undetermined foreland, with the Mazongshan arc terrane acting as the hinterland. In this study results from detailed mapping combined with a regional analysis elucidate involvement of a northward-dipping subduction system with the collision. Well-preserved fold-and-thrust belt style deformation mapped in the upper stratigraphy of the Hongliuhe Group exhibits dominantly south-southeast verging structure, including shear folding, low-angle thrust ramping, imbrication and duplexing. Restoration of a portion of a mapped outcrop-scale cross-section estimates the accommodation of a minimum of 24% shortening. Lower stratigraphy shows discrete, steeper, north-over-south dip-slip ductile shear zones that bound packages of less deformed Hongliuhe Group strata. Fault displacement is considered to have been prolonged enough to juxtapose basal formations in northerly hangingwalls against upper formations in southerly footwalls. Faulting is closely associated with the creation of large-scale brittle-ductile eye-fold structures that are postulated to be sheath folds. The most examined and mapped structure, 16km wide, is a synclinal structure with axes plunging steeply towards its center. The ellipticity of the exposed bedding traces increases towards the center of the eye-fold, implying a structural relationship with metamorphic shear zones. Except for large-scale folding, the bulk of its strata remain relatively undeformed and have preserved primary soft-sediment deformation structures indicating younging towards the center on both limbs of the synclinal structure. Stratigraphic reconstruction of the Hongliuhe Group that considers the significant faulting shows that the Group's basal conglomerates unconformably overlie a Late-Carboniferous volcanic assemblage. The clast lithotypes of the conglomeratic successions change from polymictic metamorphic rocks at the base to monomictic granitoid clasts mid-section, showing the gradual unroofing sequence of the provenance. The stratigraphic reconstruction shows a general fining upward sequence, transitioning from terrestrial to nearshore marine depositional environments that, and in conjunction with the conglomeratic successions, suggests that the tectonic setting for deposition of the Hongliuhe Group is a foreland basin. Considering the deformation styles reported in this study, the Hongliuhe Group is interpreted to be a foreland fold-and-thrust belt. Stratigraphic reconstruction of the Hongliuhe Group that considers the significant faulting shows that the Group’s basal conglomerates unconformably overlie a Late Carboniferous volcanic assemblage. The clast lithotypes of the conglomeratic successions change from polymictic metamorphic rocks at the base to monomictic granitoid mid-section, showing the gradual unroofing sequence of the provenance. The stratigraphic reconstruction shows a general fining upward sequence through nearshore depositional environments that, and in conjunction with the conglomeratic successions, give interpretation that the tectonic setting for deposition of the Hongliuhe Group is a foreland basin. Considering the deformation styles reported in this study the Hongliuhe Group is interpreted to be a foreland fold-and-thrust belt.
4

Birth, life, and demise of the Andean-syn-collisional Gissar arc: Late Paleozoic tectono-magmatic-metamorphic evolution of the southwestern Tian Shan, Tajikistan

Worthington, James R., Kapp, Paul, Minaev, Vladislav, Chapman, James B., Mazdab, Frank K., Ducea, Mihai N., Oimahmadov, Ilhomjon, Gadoev, Mustafo 10 1900 (has links)
The amalgamation of the Central Asian Orogenic Belt in the southwestern Tian Shan in Tajikistan is represented by tectono-magmatic-metamorphic processes that accompanied late Paleozoic ocean closure and collision between the Karakum-Tarim and Kazakh-Kyrgyz terranes. Integrated U-Pb geochronology, thermobarometry, pseudosection modeling, and Hf geochemistry constrain the timing and petro-tectonic nature of these processes. The Gissar batholith and the Garm massif represent an eastward, along-strike increase in paleodepth from upper-batholith (similar to 21-7km) to arc-root (similar to 36-19km) levels of the Andean-syn-collisional Gissar arc, which developed from similar to 323-288Ma in two stages: (i) Andean, I-type granitoid magmatism from similar to 323-306Ma due to northward subduction of the Gissar back-arc ocean basin under the Gissar microcontinent, which was immediately followed by (ii) syn-collisional, I-S-type granitoid magmatism in the Gissar batholith and the Garm massif from similar to 304-288Ma due to northward subduction/underthrusting of Karakum marginal-continental crust under the Gissar microcontinent. A rapid isotopic pull-up from similar to 288-286Ma signals the onset of juvenile, alkaline-syenitic, post-collisional magmatism by similar to 280Ma, which was driven by delamination of the Gissar arclogite root and consequent convective asthenospheric upwelling. Whereas M-HT/LP prograde metamorphism in the Garm massif (650-750 degrees C/6-7kbar) from similar to 310-288Ma was associated with subduction-magma inundation and crustal thickening, HT/LP heating and decompression to peak-metamorphic temperatures (similar to 800-820 degrees C/6-4kbar) at similar to 2886Ma was driven by the transmission of a post-collisional, mantle-derived heat wave through the Garm-massif crust.
5

Les récits des voyageurs britanniques en Asie centrale au XIXe siècle (1840-1890) / Nineteenth-century British travel writing in Central Asia (1840-1890)

Kantarbaeva-Bill, Irina 28 October 2011 (has links)
Le genre de récit de voyage était très prisé au XIXe siècle, plus encore lorsqu’il concernait des contrées mythiques sur lesquelles se greffait le désir d’exotisme et la recherche de racines communes de générations d’Européens. De ce point de vue, l’Asie centrale ne fait pas exception. La rivalité russo-britannique pour le partage des zones d’influence avait provoqué une multiplication des voyages vers cet Orient mal connu. Parmi les récits britanniques les plus populaires de cette époque se distinguent ceux d’Alexander Burnes, observateur militaire, d’Arminius Vambéry, orientaliste, de Florentia Sale et de Frances Duberly, épouses d’officiers, de Henry Lansdell, prêtre anglican, de Frederick Burnaby, aventurier, etc. Ces textes représentent un genre multiforme, pris à un carrefour de discours difficiles à unifier. Tout en prenant compte la diversité de cette production littéraire, notre thèse tente de mettre en lumière la question de l’altérité que pose inévitablement le récit de voyage ainsi que d’étudier les enjeux géopolitiques et littéraires de l’écriture de voyage britannique en Asie centrale au XIXe siècle. Cette historicisation nous est nécessaire pour éviter la simplification du discours orientaliste des voyageurs britanniques tout autant qu’un ensemble de stéréotypes dépréciatifs, conduisant à légitimer un comportement impérialiste. / Travel writing and experience to different parts of the world were quite popular in the 19th century, having inspired generations of Europeans to quest for exoticism and mythic origins of Western culture. Central Asia had always been one of these territories which attracted British travellers and explorers. The clandestine imperial rivalry between Russia and Britain for the mastery of Central Asia multiplied the number of British travellers towards this unknown Orient. Among the most famous travelogues of this period are those written by Alexander Burnes, a military envoy, by Armenius Vambéry, an orientalist, by Florentia Sale and Frances Duberly, officers’ spouses, by Henry Lansdell, a missionary, by Frederick Burnaby, an adventurer, and by many others. These travel narratives, versatile and heterogeneous, bring on a problem of generic definition. Our dissertation aims at examining the phenomenon of Otherness, inherent to travel writing, as well as at mapping within narrative perspective the geopolitical and literary concerns in Central Asia. By choosing this approach our work strives to avoid the reduction of the British travelling discourse in this particular geographical area to a simple legitimacy of imperial policy in the Victorian age.
6

Central Asian energy policy : cooperative non-zero sum policy on legal status and pipeline issues benefit local and global actors

Cain, Tyler Joshua 01 January 2008 (has links)
As global energy demand increases in the next century increased demand will focus global attention on geographical energy rich concentrated areas. One such area of interest is Central Asia and the primary vehicle for energy extraction in the region, the Caspian Sea. The long history of oil development is being reignited as global powers increase their interests with the dissolution of the Soviet Union and the creation of three new littorals around the body of water. Azerbaijan, Kazakhstan, and Turkmenistan create new opportunities for interested parties such as the United States, China and the European Union. The new littorals challenge the pre-existing legal status quo of Iran and Russia but no energy extraction can continue on large-scales without legal consensus and efficient modes of transportation. The aim of this study is to explain why energy production stagnation has existed in the region and prove that the most efficient and beneficial position local states, global powers, and corporations can strive towards is by adopting cooperative policy structures on all levels. The results of the study find that cooperative structures are mandatory due to the unique legal and transportation issues of the region refuting the applicability of Realism and other non-cooperative analysis models.
7

Protest mobilisation and democratisation in Kazakhstan (1992-2009)

Niyazbekov, Nurseit January 2013 (has links)
This thesis consists of two objectives which divide it into two parts. Thus, part one explores the cyclicity of protest mobilisation in post-Soviet Kazakhstan in the 1992–2009 period and part two investigates the relationship between protest mobilisation and democratisation in the 1990s, a decade marked by early progress in democratisation followed by an abrupt reversal to authoritarianism. Acknowledging the existence of numerous competing explanations of protest cyclicity, the first part of this study utilises four major social movement perspectives – relative deprivation (RD), resource mobilisation (RMT), political opportunity structures (POS) and collective action frames (CAF) – to explain variances in protest mobilisation in Kazakhstan over time and four issue areas. Adopting a small-N case study and process-tracing technique, the thesis’s first research question enquires into which of these four theoretical perspectives has the best fit when seeking to explain protest cyclicity over time. It is hypothesised that the ‘waxing and waning’ of protest activity can best be attributed to the difficulties surrounding the identification and construction of resonant CAFs. However, the study’s findings lead to a rejection of the first hypothesis by deemphasising the role of CAFs in predicting protest cyclicity, and instead support the theoretical predictions of the POS perspective, suggesting the prevalence of structural factors such as the regime’s capacity for repression and shifts in elite alignments. The second research question revolves around variations in protest mobilisation across four issue areas and explores the reasons why socioeconomic grievances mobilised more people to protest than environmental, political and interethnic ones. According to the second hypothesis, people more readily protest around socioeconomic rather than political and other types of grievances due to the lower costs of participation in socioeconomic protests. While the regime’s propensity for repressing political protests could explain the prevalence of socioeconomic protests in the 2000s, the POS perspective’s key explanatory variable failed to account for the prevalence of socioeconomic protests in the early 1990s, resulting in the rejection of the second hypothesis. The second part of the thesis attempts to answer the third research question: How does protest mobilisation account for the stalled transition to democracy in Kazakhstan in the 1990s? Based on the theoretical assumption that instances of extensive protest mobilisation foster democratic transitions, the study’s third research hypothesis posits that transition to democracy in Kazakhstan stalled in the mid-1990s due to the failure of social movement organisations to effectively mobilise the masses for various acts of protest. This assumption receives strong empirical support, suggesting that protest mobilisation is an important facilitative factor in the democratisation process. The thesis is the first to attempt to employ classical social movement theories in the context of post-communist Central Asian societies. Additionally, the study aims to contribute to the large pool of democratisation literature which, until recently (following the colour revolutions), seemed to underplay the role of popular protest mobilisation in advancing transitions to democracy. Finally, the research is based on the author’s primary elite-interview data and content analysis of five weekly independent newspapers.
8

Polycyclic evolution of the Eastern Central-Asia orogenic belt : microtectonic analysis, geochronology and tectonics in central Inner Mongolia / Evolution polycyclique de la partie orientale de la ceinture orogénique d'Asie Centrale : analyse microtectonique, géochronologie et tectonique dans le centre de la Mongolie Intérieure, Chine

Shi, Guanzhong 29 September 2013 (has links)
Il est débattue sur le temps closural finale de l'océan paléo-asiatique et la position. Certains géologues ont préconisé la suture "Solonker" marque la zone closural finale du Permien , tandis que d'autres insistent sur le fait Paléozoïque milieu. Nos trois domaines d'étude, le Hongqi , le Ondor Somme et le Mandula ont essentiel et important de résoudre ces controverses. Les unités litho-tectonique reconnus dans le domaine Hongqi-Ondor Sum sont le mélange Belt de Hongqi-Ondor Sum, la Belt de l'arc Bainaimiao, craton du Nord de Chine et les roches sédimentaires post-orogéniques. Le mélange Belt de Hongqi-Ondor Sum connu déformation ductile en deux phases et une phase de la déformation ductile-fragile. D1 est responsable de la S1 foliation, linéation minérale L1, et intrafolial pli F1. Les critères cinématiques indiquent un sens cisaillement de top-to-the-NW. D2 est caractérisée par divers taille de plis asymétriques avec axe presque NE correspondant à la poussée NW cisaillement. D3 formé le cadre régional dans le Hongqi et les zones Ondor Sum. La zone Mandula contient les sédiments olistostrome, les sédiments turbiditiques et roches volcanosédimentaires. Grains de zircons détritiques dans des échantillons sédimentaires indiquent la zone d'étude Mandula reçu des matériaux d'arc Bainaimiao et matières contemporaines de l'éruption volcanique du Permien. Les sédiments et les roches volcaniques dans la région Mandula soumettent un NW-SE ou près de N-S du raccourcissement. Les données géologiques indiquent qu'une subduction et collsion dans Paléozoïque inférieur, et rifting et fermeture rift dans Palezoic supérieur. Les fragments ophiolitiques "Solonker" sont en effet olistostrome. Composants ophiolitiques typiques ne sont pas observés dans la région Mandula. / It is hotly debated about the final closural time and position of the Paleo-Asian Ocean. Some geologists advocated the “Solonker” suture marks the final closural zone in Permian, whereas others insist in middle Paleozoic. Our three study areas, the Hongqi, the Ondor Sum and the Mandula is essential and important to solve those controversies. The litho-tectonic units recognized in the Hongqi-Ondor Sum area include the Hongqi-Ondor Sum mélange belt, the Bainaimiao arc belt, North China Craton and post-orogenic unconformably sedimentary rocks. The Hongqi-Ondor Sum mélange belt experienced two phase ductile deformation and one phase ductile-brittle deformation. D1 is responsible for the regional greenschist foliation S1, elongated mineral lineation L1, and intrafolial fold F1. The kinematic criteria indicates a top-to-the-NW shearing sense. D2 is characterized by various sized of unsymmetrical folds with nearly NE axis corresponding to the NW thrust shearing. D3 formed the regional framework in the Hongqi and the Ondor Sum areas. The Mandula area contains olistostrome sediments, turbiditic sediments and volcano-sedimentary rocks. Detrital zircon grains in sedimentary samples argue the Mandula study area received the southern Bainaimiao arc materials and coeval Permian volcanic erupting materials nearby. The sediments and volcanic rocks in Mandula area subject a nearly NW-SE or N-S compressional shortening. The geological data support that an Early Paleozoic subduction and collsioan, Late Palezoic rifting and rift closure model. The so called “Solonker” ophiolitic fragments indeed are olistostrome. Typical ophiolite components are not observed in the Mandula area.
9

L'évolution tectonique du Paléozoïque supérieur de la ceinture orogénique de l'Asie centrale du Centre-Oriental de la Mongolie intérieure / The Late Paleozoic tectonic evolution of Central Asian orogenic belt in Central-Eastern inner Mongolia

Zhao, Pan 17 October 2014 (has links)
Le Centre-Est de la Mongolie intérieure, faisant la partie sud-est de la Ceinture Orogénique de l'Asie Centrale (CAOB), est une zone de clé pour étudier l'histoire de l’accrétion-collision entre la Chine du Nord (NCC) et les blocs continentaux du Nord. Les contraintes du cadre tectonique et de la connaissance de l’évolution tectonique sont importantes pour comprendre l’accrétion de la CAOB car il n’y a pas de consensus sur le mode et la période de l'accrétion entre NCC et les blocs du Nord. Par conséquent, des études pluridisciplinaires ont été effectuées sur les roches sédimentaires et magmatiques du Paléozoïque supérieur dans le centre-oriental de la Mongolie Intérieure. Sur la base de nos études sédimentologiques, géochronologiques, géochimiques et paléomagnétiques, et compte tenu des résultats précédents en pétrographie, géochimie et paléontologie, l'évolution sédimentaire et tectonique du Paléozoïque supérieur du Centre-Oriental de la Mongolie Intérieure a été bien établie. Les études détaillées en sédimentologie et géochimie montrent une transition entre les dépôts molassiques du Dévonien à la dénudation du Carbonifère inférieur et les sédiments marins du Carbonifère supérieure vers les dépôts de bassin d'extension au Permien. D’après nos analyses détaillées des faciès sédimentaires, des caractéristiques géochimiques des roches magmatiques et nos données paléomagnétiques, nous proposons un modèle géodynamique de subduction-collision-extension post-orogénique pour le Paléozoïque au Centre-Oriental de la Mongolie Intérieure. / Central-eastern Inner Mongolia, located in the southeastern part of the Central Asian Orogenic Belt (CAOB), is a key area to study the collisional-accretionary history between the North China Craton (NCC) and the northern continental blocks. The establishment of precise constraints of this tectonic framework and evolutional history are important to understand the accretion of CAOB. However, no any consensus has been achieved about the way and the timing of the accretion between NCC and the northern blocks. Therefore, multidisciplinary studies have been carried out on the Late Paleozoic strata and magmatic rocks in central-eastern Inner Mongolia. Based on our sedimentological analyses, detrital zircon geochronological constraints, geochemical studies and paleomagnetic investigations, integrating the previous results in petrology, geochemistry and paleontology, the Late Paleozoic sedimentary-tectonic evolution of the central-eastern Inner Mongolia has been established. Detailed sedimentological and geochemical studies show a transition from the Devonian molassic deposits to the Early Carboniferous denudation and from the Late Carboniferous inland-sea sediments to the Permian extensional basin deposits. According to the comprehensive analyses on sedimentary facies, geochemical characteristics and paleomagnetic data, we propose a Paleozoic subduction-collision- post-orogenic extension tectonic model for central-eastern Inner Mongolia.
10

Geological and geophysical characterization of accretionary and collisional systems : the Central Asian Orogenic Belt and the Bohemian Massif

Guy, Alexandra 14 December 2012 (has links) (PDF)
Large-scale accretionary and collisional crustal orogenic architecture is studied combining structural geology, lithostratigraphy, geochronology and magmatic petrology with gravity, magnetic and seismic data. This multidisciplinary approach allows characterizing the structure and composition of the orogenic crust in two accretionary-collisional systems. The Central Asian Orogenic Belt (CAOB) constituting one third of the Asia continent and the Bohemian Massif are two Palaeozoic orogens formed by accretion followed by collision. It is proposed that the CAOB formed by successive Paleozoic accretion of oceanic and continental fragments followed by a late Palaeozoic to early Mesozoic N-S convergence of North Chinese and Siberian Cratons. The comparison between the potential fields and the geological data reveals an incorrect compartmentalization into different lithostratigraphic terranes. In contrast to geology the geophysical approach allows the analysis of the crustal structures on a complete thickness of crustal column. This thesis presents a compilation of geological data combined with unique gravity and magnetic results which are integrated into a preliminary model for the architecture of the continental crust. Conversely, an important collection of complementary data is available for the Bohemian Massif, allow more precise 3D geophysical forward modeling. In this area, geophysical data reveal the occurrence of an allochtonous lower crustal layer with a felsic composition. This indicates that the Variscan orogenic crust actually resulted from the accretion of contrasted crustal fragments.

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