Dissertations / Theses on the topic 'Géomorphologie et Géologie'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Géomorphologie et Géologie.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Gagné, Hubert. "Géomorphologie et géologie marine du Quaternaire du secteur Trois-Pistoles-Forestville, estuaire du Saint-Laurent (Québec)." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25645/25645.pdf.
Full textCarretier, Sébastien. "Cycle sismique et surrection de la chaîne de Gurvan Bogd (Mongolie) : approche de la géomorphologie quantitative." Montpellier 2, 2000. http://www.theses.fr/2000MON20204.
Full textTannouch, Bennani Souad. "Paléolacs plio-quaternaires et leurs couvertures sédimentaires récentes (Souss Central, Maroc)." Nancy 2, 2003. http://www.theses.fr/2003NAN21024.
Full textThe middle part of the Souss plain, on both sides the eponymic main stream, is characterized by the existence of large evident sedimentary structures in the global morphology which are the large atlasic and anti-atlasic alluvial fans, the alluvial terraces and fields of dunes which reinstall in occasion of long drought. Except these sedimentary structures, the detection of a lakeside system remains rather difficult. The indicators of the existence of palaeolakes or palaeoplayas limit themselves to the planar aspect of certain parts of the Souss plain, to the conservation or not of the Argan forest, but especially in the existence of calcareous benches at the base the oued's left bank. The Souss lain was commanded by a tectonic activity bounded to the recurrent faulting of inherited faults, as weil in the basin as in the plain, and in a subsidence which probably continues. Two generations at least of Plio-Villafranchian palaeolakes were established within the depression. Their summit was covered by the deposits of terraces of the oued Souss, by the deposits of the High atlasic's and the Anti-atlasic's alluvial fans distal deposits and by dune fields. The wet limate in regular precipitations which reigned over the Souss plain during the Plio-Villafranchian left place to a succession of paleoclimates responsible of major notches and construction of new generations of alluvial fans on High-atlsic's and Anti-atlasic's piedmonts; the Anti-atlasic's piedmonts were drier and have allowed the installation of dunes. More wet and more dry phases altemate undoubtless during aIl the Quaternary. The unique phases identified here are situated within the "Tardi-Soltanian" and the Upper Holocene. The last phase of increasing aridity settled down since the Upper Holocene until the Current, and was interrupted by wetter episodes. The anthropological action has stressed many aridification aspects: prolonged oued drying, gulliying, fall of phreatic water-table. The Souss epression which saw lakes developing over more than 1000 km2 during PlioVillafranchian and which was yesterday even the larder of the Saâdians (sugar cane culture) offers today sorne land drought aspects
Prognon, François. "Provenance du matériel à l’origine des formations pédologiques quaternaires des archipels des Bermudes et des Bahamas." Paris, ENMP, 2006. http://pastel.paristech.org/3287/01/Thèse_PROGNON.pdf.
Full textBermudan and Bahamian Quaternary deposits are characterized by the alternation of carbonates and paleosols. Up to now, atmospheric material, especially Saharan dust, was considered as the main component of the pedological formations. XRD analyses revealed that the mineralogical assemblage of the Bermuda paleosols predominantly includes carbonates, clay minerals (kaolinite, chlorite and chlorite/vermiculite), phosphates, aluminium and iron oxides/hydroxides. It is strikingly close to the mineralogy of the altered Bermuda volcanic seamount, but noticeably different from the mineralogy of Saharan dust. Moreover, volcanic lithoclasts are found in numerous paleosol profiles all over the archipelago, in all the recorded time intervals. We thus consider the volcanic seamount as the main source of non-carbonate minerals detected in the paleosols. The atmospheric dust reaching Bermuda all along the Quaternary period is probably diluted by the local flux of insoluble residues and remains undetectable by the XRD method. Carbonates dominate Bahamian paleosols mineralogical assemblage. Recent formations contain kutnahorite, older hydrotalcite. We carried out a comparative study on the evolution of the San Salvador and Eleuthera paleosols mineralogy. It is supported by the speciation model CHESS. It demonstrates that soil evolution is driven by the local platform physiography and by the substratum mineralogy. The clay assemblage from Bahamian paleosols and marine sediments is inherited from North African and probably from North American sources (Mississippi Valley Loess)
Lague, Dimitri. "Dynamique de l'érosion continentale aux grandes échelles de temps et d'espace : : modélisation expérimentale, numérique et théorique." Rennes 1, 2001. https://tel.archives-ouvertes.fr/tel-00003948.
Full textVu, Van Tich. "La chaîne indonésienne au Vietnam : pétrologie et géomorphologie du bloc métamorphique de Kon Tum." Montpellier 2, 2004. http://www.theses.fr/2004MON20008.
Full textLajeunesse, Patrick. "Géomorphologie et géologie du quaternaire de la région de la rivière Nastapoka, côte est de la baie d'Hudson, Québec." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ56840.pdf.
Full textBeaulieu, Olivier. "Géologie du Quaternaire et géomorphologie de la région de la rivière Biscarat, côte Est de la baie d'Hudson, Québec nordique." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25696/25696.pdf.
Full textDjeuda, Tchapnga Henri Bosko. "Géologie et hydrogéologie d'un secteur de la zone mobile d'Afrique centrale : région de Poli, Nord-Cameroun." Grenoble 1, 1988. http://www.theses.fr/1988GRE10004.
Full textCastelltort, Sébastien. "Origine et modification des cycles stratigraphiques à haute-fréquence (10's à 100's ka). Rôle des déformations courte longueur d'onde et modélisation du comportement des systèmes fluviatiles." Rennes 1, 2003. https://tel.archives-ouvertes.fr/tel-00003936v2.
Full textBenaouali-Mebarek, Zahra Narimane. "Convergences et soulèvement dans les fronts de chaînes : étude comparée des Rocheuses Canadiennes et du système Tell-Atlas en Algérie." Cergy-Pontoise, 2008. http://www.theses.fr/2008CERG0422.
Full textWe are interested here about the uplift and erosional history derived from kinematic and thermal modeling for two well known fold and thrust belt transects: the Canadian Rockies between Banff and Calgary and the Saharan Atlas - North Algeria profile crossing the Tell in the north to the Saharan Platform in the south. In this context of alternance of subsidence and uplift episodes, it is very important to reconstruct in detail the burial and thermal evolution of each potential source rocks identified in the basin, and which undoubtedly acquired their current maturity during various basin evolution episodes. To quantify the amount of erosion, vertical uplift and history of the lithosphere flexure in both regions, we have developed an integrated approach using 1D backstripping, 2D kinematic simulations and gravity calibration at the lithospheric scale, in order to : constrain the different sedimentary and topographic profiles through time, for the entire section (i. E. For the autochthon as well as for the foothills and the hinterland). This implies we must estimate the former thickness of eroded layers. For this purpose, we have used both restoration software, which provides results based on geometrical considerations, and a decompaction software, which provides independent estimates and subsidence curves, based on 1D thermal modeling, quantify the same parameters and establish the erosion profiles on key portions of these transects by defining the initial architecture of sedimentary strata and thrust faults. We have restored the section in its pre-orogenic configuration, starting from the present day architecture of the balanced cross-section. The majority of structural units has been restored by a flexural slip method. Then we had to specify the timing of each individual thrust fault motion. The basic assumption made for managing thrust initiation during this study was a forward thrusting sequence that propagates from the hinterland toward the foreland. For each deformation stage, the topography was reconstructed using the critical taper theory The final objective of this study is to establish a representative deformation scenario at a regional scale for both regions, in order to constrain in-depth the basement geometry, the Moho depth, as well as the attitude of the lithospheric flexure, and the controls applied by the deep lithosphere on surface processes such as deformation, erosion and thermicity
Fassi, Driss. "Les formations superficielles du Saïs de Fès et de Meknès du temps géologique à l'utilisation actuelle des sols." Paris 1, 1993. http://www.theses.fr/1993PA010604.
Full textThe pliocene has been essential in performing the continental Saïs structures. The quuternary realised original materials for pedogenesis, such as caliche, tufa and travertine. Soils are organised according to soilscape models. XXth. Century human intervention had disruptive impacts on pedological and hydrological environments
Paris, Raphaël. "Rythmes de construction et de destruction des édifices volcaniques de point chaud : l'exemple des îles Canaries (Espagne)." Paris 1, 2002. https://tel.archives-ouvertes.fr/tel-00123713.
Full textSquarzoni, Cristina. "Mesure des champs de déplacement de surface et modélisation numérique des glissements de terrain." Lyon 1, 2003. http://www.theses.fr/2003LYO10262.
Full textAmbert, Martine. "Contribution à la connaissance du patrimoine naturel languedocien : enjeux, concepts et applications." Lyon 2, 2004. http://theses.univ-lyon2.fr/documents/lyon2/2004/giubergia_m.
Full textThe main purpose of this thesis is to point out that geomorphology plays an essential part in matters of heritage which have become issues very much to the forefront of modern society's preoccupations. These issues have been fostered by a number of university-led experiments which mutually complete each other. The choice of region for the study was evident by reason of its scenic diversity and its laboratorial aspect. The process was initially sparked off by social demand. Further to the institutional approach, came a spontaneous social demand by users, which as been examined in depth by direct contact with the public in events involving the landscape and heritage of highly notable geomorphological sites (Cirque de Navacelles and Causse de l'Hortus). The major factor in this widespread demand is its latent nature. This cultural need established, the second part deals more widely with what is offered to meet it. Significant negative and positive experiences are examined to determine what are the new issues relating to society and discipline. The conclusion reached is the existence of a geomorphological knowledge heritage which give us a better understanding of the environment and helps us construct the identity of the sites and hence the appropriation of these lands by humans. The work ends with an attempt at theory construction. This starts with a defence of the role played by geomorphology in the approach to landscape, from a point of view complementing that of geologists. Then the stages of the research process are summarised from the position of the "lookout" to that of the broadcaster of knowledge
André, Marie-Françoise. "Dynamique actuelle et évolution holocène des versants du Spitsberg : Kongsfjord-Wijdefjord, 79o Nord." Paris 1, 1991. http://www.theses.fr/1991PA010633.
Full textWhat are the rates of evolution of contemporary arctic mountain slopes? Are they mainly relic or rapidly changing? This thesis seeks to answer this central question of polar geomorphology, based on a quantitative approach between classical description and recent modelling studies, with particular attention drawn to the relationships between slope processes and vegetal colonization. Central and northwestern spitsbergen were selected for a study area to attempt a definition of the types of slope evolution, and to evaluate the rates of holocene activity. Rates of rockwall retreat and debris accumulation vary at least from 1 to 1 000, the major factors responsibl e for such a diversity being relevant to the geological and topographical background and the pattern of glacial dynamics. Using dating methods such as lichenometry, this thesis also includes new data upon the frequency of extreme meteorolog ical events that result in high geomorphic activity
Pech, Pierre. "Contribution à l'étude de la dynamique des versants en montagne alpine : l'exemple de l'Ossola (Alpes centrales-Italie du Nord)." Paris 1, 1988. http://www.theses.fr/1988PA010526.
Full textBogna, Ovesca and Anza, three valleys to the east of Mont-Rose (4633m) belong to the watershed of Toce, a tributary of the river Tessin. Their slopes and differences in altitude are very important. The valley slopes are cut out in metamorphic rocks of intern alpine zone. The resistant gneisses which breack through in places on western part and the micaschists that are localized on the eastern part, have been eroded by great quaternary glaciers the relict sediments of tardiglacial and postglacial fluctuations-moraines; screes- can be found in high mountain. Biochemic erosion and frost splitting are now acting o wide spaces. Yet the slope is the essential agent of de- gradation. Screes, solifluction, avalanches, mud-flows come one after the other on the same valley slopes. The amount of debris depends on the resistance of the rocks (>10m3 for quaternary accumulations and <1m3 for gneisses) and on the type of processes (<1m3 for frost splitting;>1m3 for avalanches; >100m3 for mud-flow). A map of potential natural hazards has been drawn from a statistical study
Chevrier, Vincent. "Approche magnétique de la formation du régolithe martien : étude sur analogues terrestres et expérimentaux." Aix-Marseille 3, 2004. http://www.theses.fr/2004AIX30061.
Full textResults of Martian spacecraft missions have evidenced the presence of a strongly altered regolith, of which possible origin is alteration of primary basaltic substrate by atmosphere and hydrosphere. This hypothesis of weathering is tested on a terrestrial analogue: the Ferrar dolerite from Antarctic and on some phases experimentally altered in a simulated Martian atmosphere. Meteoric weathering under Martian conditions produces strongly magnetic phases, either inherited from parent bedrock (titanomagnetite), either from exogenic contribution (iron metal), or neoformed (maghemite). Red ferric (oxy)hydroxides (goethite and hematite) as well as most secondary phases detected in the Martian regolith, i. E. Sulfates and carbonates, may also result from weathering. Finally this study demonstrates that weathering may occur in the absence of O2. Water is then the main reactive species, responsible for oxidation reactions of the surface
Meghraoui, Mustapha. "Géologie des zones sismiques du Nord de l'Algérie : paléosismologie, tectonique active et synthèse sismotectonique." Paris 11, 1988. http://www.theses.fr/1988PA112220.
Full textGeomorphic studies of profiles conducted in 1986 across the El Asnam fault zone, the site of destructive earthquakes in both 1954 and 1980 allow quantitative evaluation of state Quaternary vertical offsets. Cumulative offsets were obtained with 13 profiles across both the main thrust fault and the secondary normal faults. 7 of the scarps levelled display three to five events including the 1980 earthquake and 5 others show cumulative vertical offsets at least eight times greater than that of 1980. On the ether hand 22 profiles conducted across the thrust breaks of the October 10, 1980 earthquake (M=7. 3) give more accurate values of co-seismic vertical displacements than those previously measured and confirm the existence of three segments A, B, and c along the strike of the fault. Dating of events identified on profiles, for which trench studies nearby have been conducted, yields the following results : in the last 1030 ±135 years, which is a cluster period of large seismic events, we obtain two uplift rates of 2. 42 mm. Y⁻¹ and 0. 97 mm. Y⁻¹respectively along the fault, as well as a recurrence interval of 315 years. For a longer time span (late Holocene), we obtain average minimum and maximum uplift rates of 0. 6 mm. Y⁻¹ and 1. 52 mm. Y⁻¹ respectively, and a recurrence interval of 710 years. An uplifted terrace located at the junction between segments A and B and dated approximately at 100,000 years implies an uplift rate of 0. 5 ±0. 05 mm. Y⁻¹ which is comparable to the minimum late Holocene uplift rate. The slip rate variability thus appears to depend not only on the uneven temporal distribution of large earthquakes (with M>7), but also on the variations in the amplitude of vertical displacements along different segments of the fault. Hence, the El Asnam thrust behavior is variable and episodic along strike, of the fault and is characterized by clusters of large events separated by longer periods of dormancy
Hammor, Dalila. "Du panafricain au miocène : 600 millions d'années d'évolution polycyclique dans le massif de l'Edough (Algérie nord-orientale) retracés par la pétrologie, la tectonique et la géochronologie (U/Pb, Rb/Sr, Sm/Nd et 39Ar/40Ar)." Montpellier 2, 1992. http://www.theses.fr/1992MON20170.
Full textThorey, Clément. "Dynamique des intrusions magmatiques peu profondes : théorie et application à la détection d’intrusions planétaires." Sorbonne Paris Cité, 2015. https://theses.hal.science/tel-01278432.
Full textIntrusive magmatism plays a fundamental role in the accretionary processes of terrestrial crust. Indeed, when magma is forced to the surface, only a small amount of it actually reaches that level. Most of the magma is intruded into the crust where it solidifies into a wide range of features, from the small scale sills and laccoliths to large scale batholiths (several hundred kilo-meters in size). The topographic deformation that could be caused by shallow intrusions can be constrained by observations of planetary surfaces ; that is volume, shape and other dimensions of intrusions can be quantified. However, such observations must be linked to dynamic models of magma emplacement at depth in order to provide insights into magma physical properties, injection rate, emplacement depth and the intrusion process itself. In this thesis, we first investigate the relation between the morphology of shallow intermediate-scale magmatic intrusions (sills and laccoliths) and their cooling. We propose a model for the spreading of an elastic-plated gravity current with a temperature-dependent viscosity that accounts for a realistic magma rheology, melt crystallization and heating of the surrounding medium. The mechanisms that drive the cooling of the intrusions vary from Earth to the Moon and the ability of the model to reproduce the final morphologies (aspect ratio) of terrestrial laccoliths and low-slope lunar domes is examined. On the Moon, the emplacement of magmatic intrusions into the crust has also been proposed as a possible mechanism for the formation of floor- fractured craters. We propose a model for an elastic-plated gravity current spreading beneath an elastic overburden of variable thickness. We find that several characteristics of floor-fractured craters are indeed consistent with the emplacement of large volumes of magma beneath their floor. In addition, using the unprecedented resolution of the NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission, in combination with topographic data obtained from the Lunar Orbiter Laser Altimeter (LOLA) instrument, we show that lunar floor-fractured craters present gravitational anomalies consistent with magmatic intrusions intruding a crust characterized by a 12% porosity. The implications in terms of lunar evolution are examined
Monnier, Olivier. "Impacts des changements climatiques sur les systèmes cordon-zone humide holocènes : éléments d'analyse géomorphologique : exemples corses et bretons." Paris 1, 2000. http://www.theses.fr/2000PA010542.
Full textGonga-Saholiarilava, Nahossio. "Quantification du relief terrestre à partir de grilles numériques : méthodes géomorphométriques, potentiel, analyse critique : tests et applications dans des zones de fronts montagneux." Paris 7, 2010. http://www.theses.fr/2010PA070075.
Full textThis work brings together results from four years of both professional experience and self-study focusing on digital elevation models and grid studies, which today form an important basis for terrestrial surface analysis and research in quantitative geomorphology. A didactic inventory of the characteristics and structures of elevation models and their related geomorphometric components is proposed. Analytical and numerical development of the mathematical derivatives of elevation (i. E. Slope and local slope curvatures) and techniques for assessing errors and error propagation in DEMs are proposed, with emphasis on spatial autocorrelation mapping as a tool for locating error hotspots. Comparative tests were carried out on selected geographical areas exhibiting mountain fronts with specific structural and geomorphologic features. Algorithms and methods for the calculation and interpretation of primary and secondary topographic attributes were designed and tested for their suitability to the chosen terrain conditions. I have also developed a numerical script that performs an automated search of geomorphologic features such as river knickpoints on multiple drainage networks. This prototype is designed to locate knickpoints rapidly and effectively, e. G. For exploratory studies prior to field investigations or for mapping crustal deformation and/or structural geology on a regional scale. Verifications and tests are carried out on three mountain fronts with differing characteristics: the Sierra Nacimiento, New Mexico; the Weber segment, Wasatch Mountains, Utah; and the Solsona-Boixols area, eastern Spanish Pyrénées. Based on ground-truth checks, the script could identify 50 to 80% of knickpoints depending on DEM source and ground resolution. Improvements to the script performance ratings call for the introduction of additional geomorphometncal constraints. In order to be process-based as well as purely geomorphometric in nature, these must reflect the dynamics of river flow. A desirable target would be a detection capacity ranging between 70 and 80% whatever the DEM and the mountain terrain considered. This script offers a reproducible numerical tool based on the key geomorphometric parameters of elevation grids including considerations of error, precision, accuracy and structure. It can be readily incorporated into software commonly used in academic and industrial applications that rely on drainage system characteristics for interpreting surface or subsurface dynamics
Darmame, Mohammed. "Le littoral entre Jorf Lasfar et Souira Qdima (Maroc atlantique) : milieu naturel et conséquences des aménagements." Paris 10, 1994. http://www.theses.fr/1994PA100129.
Full textThe first part of this thesis describes the evolution of the coast from Ouljien. Different areas testify for a Neolithic human occupation including a great number of life places on alluvial and colluvial formations dating back to the superior soltanian. The second part proposes a description of the cliffs in the area. The evolution shows local risks for the northern areas of Safi. The harbor development in that city has entailed an ablation in the southern area of the main pier. The frenetic exploitation of the beaches sand has increased the coast limits moving back like in Sidi Bou Denyane. The third part lists the different seaside resources, describes how they are managed and asks questions about that management. Then it shows the various pollution sources along the coast and attempts to analyze the consequences on the environment. The fourth part is an atlas helping to the protection of this environment in case of oil pollution
Le, Roux-Mallouf Romain. "Déformation Holocène de l’Himalaya du Bhoutan : apport de la géomorphologie et de la paléosismologie." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT142/document.
Full textThe Himalayan arc is one of the most active intra-continental mountain belts in the world. Over the last centuries, several major earthquakes (Mw > 7.5) have struck this arc. The dramatic effects of the Gorkha earthquake sequence in 2015 pointed once again the crucial need to improve seismic hazard assessment of this area.Geological explorations of the Himalayas since the late 19th century have emphasized a 2500-km-long roughly cylindrical structure, with striking continuity of main units and thrust faults. However recent geophysical and geological investigations have revealed lateral variations. The relationship between these variations and earthquakes segmentation along the arc remains poorly constraint. The maximum size and the occurrence probability of such earthquakes are still a matter of debate.For instance, the seismic behavior of Bhutan remains enigmatic. The present-day low seismicity rate observed in this area can reflect two opposite fault behaviors: an aseismic creeping zone or a zone of stress accumulation for future great earthquakes as the others parts of Himalayas. The main objective of this thesis is to bring new constraints on the deformation of the Bhutan Himalayas, at different space- and time-scales, through morphotectonic and paleoseismological approaches.The first part of this thesis focuses on the vertical deformation assessment along a N-S transect in western Bhutan and along the Main Frontal Thrust, which is the southern-most thrust in southern Bhutan. In the past three years, we have carried out three fieldwork campaigns to sample (1) frontal terraces to assess Holocene uplift rates, (2) watershed basins to quantify short term denudation rates (< 20 ky) derived from cosmonuclides $^{10}$Be and (3) hinterland alluvial terraces to quantify the Holocene incision rate. Frontal Holocene uplift rates obtained in Bhutan are consistent with those obtained in the others parts of Himalayas. Furthermore, our results reveal a variation in the geometry of the Main Himalayan Thrust between eastern Nepal and western Bhutan.The second part focuses on several paleoseismic studies along the west and central bhutanese Himalayan front. Different sites were investigated during three fieldwork campaigns. Detritic charcoals sampling and modeling suggest the occurrence of at least five surface-rupturing earthquakes during the last ~2700 years. These results demonstrate that the present-day low seismicity rate observed in Bhutan is not representative of the seismic activity at longer time scale. At regional scale, they also take part of a broader discussion on the probability of occurrence of a magnitude 9 earthquake along the Himalayan arc
Boujelben, Abdelkarim. "L'hydrosystème des sebkhas al Kalbiyya et Halq al Minjil : dynamiques hydro-morphosédimentaires, paléoenvironnements et évolution des paysages pendant l’holocène." Caen, 2015. http://www.theses.fr/2015CAEN1034.
Full textThe thesis focuses on the downstream part of the catchment area of central Tunisia, from the continental sebkha al Kalbiyya to the coastal sebkha Halq al Minjil. The extent and variety of forms and training and development of ancient lake and lagoon deposits pose major problems concerning the evolution of the Holocene hydro-morphosedimentary sebkhas operating current and the immediate fluvial system. This work focus on their origins and their paleoenvironmental and morphogenic expressions by multidisciplinary and multiscale approach. The main results of the study are: the complexity of the spatiotemporal distributions and the interesting stratigraphy of very heterogeneous sediments of sebkhas (bottoms and borders), the succession of fourteen major Holocene phases of sedimentation and four continental systems and paraliques of hydrological functioning in each of al Kalbiyya and Halq al Minjil enclaves, the plurality of multi-phase hydroeolian models of the sebkhas borders, the extent of the deposits and the multiplicity of formational morphometric characters and a variety of molded, especially historical age in the fluvial system, the Holocene instability of morphogenesis and environments whose factors are essentially subservient to eustatic variations and pluvio-thermal variability of a Mediterranean semi-arid climate, the relative sea level rise of +71 cm to 4965±35 BP and +187 cm at 4365±50 BP, the first signs of agro-pastoral societies influence on the environment are recognized during the III millennium BC, the role of neotectonics (subsidence, warping, fracturing) is located
Baloka, Roger Faustin. "Les phosphates méso-cénozoi͏̈ques de sub-surface du Bassin du Congo : paléoenvironnements et pétrogénèse." Perpignan, 1994. http://www.theses.fr/1994PERP0213.
Full textSimon, Brendan. "Rift du Lac Albert, Ouganda, Rift Est Africain : déformation, érosion, sédimentation et bilan de matière depuis 17 Ma." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S175/document.
Full textThe aim of this work is (1) to study the relationships existing between deformation, erosion and sedimentation and (2) to quantify the erosion-sedimentation budget in a continental rift: the Rift Albert located in Uganda, in the north of the Western Branch of the East African Rifts. This study consists in a triple analysis of the deformation, the sedimentary infilling (biochonostratigraphy, sedimentology and sequence stratigraphy) and the landforms (geomorphology) based on the interpretation of subsurface and surface data. An age model of the sedimentary infilling has been obtained by combination of biotratigraphic data, sequential correlations and paleoprecipitation variation curves. The sedimentological analysis led to the characterization (1) of the sediments source – most of the quartz grains coming from the erosion of a lateritic profile (with low transportation) – and (2) of the depositional environment which consist of perennial deep (<100 m) feeding by flood deposits, without evidences of alluvial fan. This sedimentological study, along with the analysis of landforms allow to reconstitute the evolution of the basin and of its deformation: (1) 55-45 Ma: formation of laterites corresponding to the African Surface during the very humid period of the Lower-Middle Eocene; (2) 45-22 Ma: stripping of the African Surface in response of the beginning of the East-African Dome uplift and formation of a pediplain connected to the Atlantic Ocean; (3) 17-2.5 Ma: Initiation of the Lake Albert Basin around 17 Ma and creation of local base levels (Lake Albert, Edward and George) on which three pediplains tend to adapt; (i) 18—16 to 6.2 Ma: "Flexural" stage (subsidence rate: 150-200 m/Ma; sedimentation rate 1.3 km3/Ma between 17 and 12 Ma and 0.6 km3/Ma from 12 to 6 Ma) – depocenters location poorly controlled by fault; (ii) 6.2 Ma to 2.5 Ma: Rift stage 1 (subsidence rate: > 500m/Ma up to 600-800 m/Ma; sedimentation rate: 2.4 km3/Ma) – Rifting climax; (4) 2.5-0.4 Ma: uplift of the Ruwenzori Mountains and shifting from an alluvial system to a network of bedrock river incision – Rift Stage 2 (subsidence rate: 450 to 250 m/Ma; sedimentation rate: 1.5 km3/Ma); (5) 0.4-0 Ma: long wavelength downwarping, initiation of the Lake Victoria trough, drainage network inversion and uplift of the present-day escarpment.The measurement of the erosion-sedimentation budget show the same order of magnitude with, between 17 and 2.5 Ma, an excess of eroded material (22 000 km3) compared to the sediment volume deposited in the basin (19 000 to 18 000 km3). This difference of volume of 16% can be explained by the high chemical erosion occurring during this period, which one is depreciated by the difference of mineralogy of the clays between the catchment (kaolinites) and the sedimentary basin (dominantly smectites), the neoformation of smectites from kaolinites needing the input of element available in the solution resulting from the chemical weathering of the substratum
Moulin, Loïc. "Instabilités en tresses des systèmes fluviatiles : études de rivières de Nouvelle-Zélande et modélisation." Rennes 1, 2009. http://www.theses.fr/2009REN1S164.
Full textTo better characterize and understand the variability of river's dynamics, including notably the complex braided morphology, we propose a double approach, based both on collection, analysis, and correlation of natural system's data and on numerical modelling. The highly-dynamic braided rivers, ancient or present, in New Zealand, are our reference natural labs. Through the dependence of bedwidth on discharge and sediment load, we highlight the specificity of widening dynamics of braided systems. With descriptors quantifying the complex organization of braided’ pattern, we characterize on high resolution satellite imagery, instability intrinsic geometrical properties, and morphological adjustments to external forcings. Our study explores also a temporal geomorphologic transition, with the example of terrace abandonment’s history of Rangitikei River. We use the numerical model €ros as a simplified tool to assess the effect of slope, discharge, and sediment load on fluvial dynamics, and to reconstruct schematically the balance between basal and lateral erosion and deposition processes allowing emergence of braided instabilities
Heintz, Maggie. "Structure et déformation du manteau continental sud américain : apport de la tomographie en ondes de surface et de l'anisotropie sismique." Montpellier 2, 2003. http://www.theses.fr/2003MON20047.
Full textMaréchal, Anaïs. "Tectonique active de la zone de collision Yakutat - Nord Amérique : apport du GPS et de la géomorphologie à l'étude de la partition de la déformation." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS282.
Full textIn SW Yukon – SE Alaska, the boundary between the Pacific and North America plates is characterized by a syntaxis at the transition between the Aleutian subduction to the W and the Fairweather – Queen Charlotte strike-slip faults to the SE. The relative motion is oblique to the main fault structures, and the area is marked by the Yakutat block collision. From the Chugach – Saint Elias mountains in the plate boundary zone (up to 6 000 m high) to the intraplate strike-slip faults, markers of the present-day deformation give information on its partition in the system.During my PhD, I first measure surface deformation using a dense GPS network, deployed up to 500 km inland the North America plate. After precise processing and corrections of transient effects in the area (postseismic and glacial isostatic rebound), a new residual velocity field is produced for the syntaxis area, from which I derive strain rates. Those data allow me to quantify the fault slip rates for Fairweather and southern Denali strike-slip faults, and to characterize a bi-modal deformation pattern: Along the plate boundary, the deformation is localized on large-scale structures (accretionary prism to the W, Fairweather to the E); In the syntaxis area, strain rates are the highest and the GPS data shows a diffuse intraplate deformation, similar to an indentor pattern. The Yakutat block seems to strongly drive the North America plate deformation.This indentor pattern induces strong lateral variations on the large intraplate faults: the Denali – Totschunda – Duke River system. In a second part, I realize a regional geomorphological study to characterize the role and slip rate of those faults. From very high-resolution Digital Elevation Models (~ 1 m), a detailed cartography is done. On the basis of fieldwork observations, I measure offsets of fluvial and glacial markers, which are sampled for dating. A dextral cumulative deformation is highlighted on the northern Denali Fault, where as all southern Denali is marked by vertical deformation. This study allows me to quantify new slip rates for the system Denali – Totschunda – Duke River, and to show the leading role of the Totschunda (~ 14 mm/a) and Duke River (~ 6 mm/a) faults, contrary to the Denali Fault (~ 1 mm/a) North of the syntaxis.The new tectonic model for the Yakutat collision provides an important case study for the understanding of indentor systems. The concomitance of a rigid-block deformation (to the West) and diffuse deformation (to the East), as well as the near-zero slip rate on the lithospheric-scale southern Denali Fault highlight the major control of boundary conditions and the structural heritage on the orogen deformation
Le, Corre Lucille. "Géologie de Titan à partir des données de spectro-imagerie infrarouge et Radar de la mission Cassini." Nantes, 2009. http://www.theses.fr/2009NANT2108.
Full textCassini spacecraft, launched in 1997 and arrived in July 2004 at Saturn, provides images of Titan's surface in the near-infrared, medium infrared ranges and in the radio wavelengths range corresponding to the Cassini radar instrument. Previously, Titan’s surface, hidden by a thick methane-rich atmosphere opaque for the visible light, was unknown. The main work in this thesis is to analyze the dataset acquired by VIMS (Visual and Infrared Mapping Spectrometer), in order to map Titan's surface. For each pixel of an given image, VIMS observes a spectrum between 0. 35 and 5. 11 μm. Atmospheric windows of methane allow to see the surface through the haze of aerosols and gases. By creating global mosaics of infrared images, we can infer different types of terrains. Geological features, such as cryovolcanoes, dune fields, lakes, fluvial channels, and impact craters, are studied thanks to the combination of VIMS et radar images in SAR mode in a geographic information system. They show a good correlation in morphology between radar and infrared datasets. The study of a particular cryovolcanic flow demonstrates that the composition can match spectra of mixtures of ices containing CH4, H2O, and CO2. Global mapping is useful to study the spatial distribution of geological units, features and correlation between datasets aiming to understand the nature and erosion processes prevailing on Titan's surface. A global crater count using the available radar swaths permits to estimate the surface age between 200 Myr and 2 Gyr
Chantreau, Yoann. "Les formations fluviatiles pléistocènes de la moyenne et basse Sarthe : approche géoarchéologique." Rennes 1, 2011. http://www.theses.fr/2011REN1S159.
Full textThis work deals with the Sarthe River system between le Mans and Briollay using a geoarchaeological approach. In this area, the river drains low table-lands in the boundary between the Paris Basin and the Armorican Massif. The study of three valley sectors allows us to bring to light fluvial system variations along the longitudinal profile. The stepped terraces of the Sarthe River are interpreted as the response of the fluvial environments to climatic cyclicity, superimposed on a background of slow tectonic uplift, but some valley sectors don't match to this description. The lower part of the Sarthe River seems to point out entrenched terraces due to the Loire baselevel variations which are linked to eustatism. A limited river section (10 km long), where the Sarthe River adopts nowadays a sinuous course, shows partially entrenched terraces. At this section, the hard Jurassic limestone substratum seems to be the principal cause of this particularity. The Sarthe valley is filled with alluvial sheets showing recurrent features between terrace levels. This characteristic is closely linked to the Quaternary climatic cycles but the sandy Cenomanian substratum seems to have played a crucial role in the sandy sedimentation, especially in the upper part of the alluvial sheet fill. The mapping of low and middle Paleolithic human settlements in the Sarthe catchment area allows us to demonstrate the raw materials deposits effect on prehistoric human establishment. This study enables us to highlight the potential of the lower section of the Sarthe River in the human artifacts preservation due to interglacial deposits which are linked to entrenched terraces morphology
Da, Rocha Araujo Paulo. "Les phosphorites d'âge protérozoique moyen de Rocinha (Minas Gerais, Brésil) : genèse et évolution d'un gisement de phosphate tectonisé et métamorphisé au Brésilen (=600Ma)." Aix-Marseille 3, 1988. http://www.theses.fr/1988AIX30003.
Full textGout, Bertrand. "Influence des apports terrigènes dans les écosystèmes lagonaires de Mayotte et de Nouvelle-Calédonie (Province Indopacifique) : impact sur les peuplements benthiques." Montpellier 2, 1991. http://www.theses.fr/1991MON20021.
Full textThomas, Franck. "Caractérisation des déformations récentes en Provence par une approche pluri-disciplinaire : apport de la géomorphologie quantitative et de la paléosismologie." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0095/document.
Full textThis manuscript deals with a multi-scale geomorphological and tectonic analysis of Provence, a region where large scale historical earthquakes (intensities of VIII or even IX) have been recorded during the last centuries (e.g. in Lambesc, 1909). If the intensity of historical earthquakes is relatively high in Provence, the region undergoes a weak microseismicity, hence the need for a tectonic, geomorphologic and paleoseismologic approach to understand the recent deformations.In order to evaluate the large-scale morphogenesis in Provence, we evaluated the denudation rates of the carbonate ranges of the region by measuring 36Cl cosmogenic isotope concentrations. We obtain comparable denudation rates between different sites (in the order of 20-60 mm/ka) and comparable to previous studies in this type of contexts (e.g. Ryb et al., 2014a, b), except for the Grand Luberon and the Lure mountain, which erode more quickly (up to 140 mm/ka). This approach was applied on a smaller scale by focusing on the Petit Luberon, where we compare the denudation of the summit surface to the denudation averaged over several watersheds on its southern and northern flanks.Finally, we implemented a multi-disciplinary approach on a local scale, associating high-resolution mapping, electrical resistivity measurements, paleoseismology, granulometry, 14C and OSL dating, in order to obtain a better understanding of Quaternary and Holocene behavior of a fault segment located in Vinon-sur-Verdon. Our analysis confirms that deformation occurred in the last 200 thousand years on this contact but demonstrates the absence of deformation in the last 16000 years
Ahamdach, Noureddine. "Mobilité de l'uranium, du thorium et des éléments de terres rares au cours de l'altération latéritique, de l'infiltration d'eau météorique en milieu granitique et de la diagenèse d'une formation volcano-sédimentaire." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL125N.
Full textLacoste, Aurélien. "Glissements de terrain, surpressions de fluide et incisions : caractérisation géologique et modélisation : exemple du complexe de Waitawhiti, Nouvelle-Zélande." Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10119/document.
Full textLandsliding is a major erosional factor in mountain ranges. The study of the triggering factors and of the parameters controlling the evolution of gravitational instabilities is therefore an important stake in the understanding of the processes leading to the denudation of reliefs and in the prevention of the associated natural hazard. Multiple gravitational instabilities affect the Coastal Ranges of the North Island of New Zealand. The detailed analysis of the Waitawhiti sliding complex, located in the core of the Tawhero syncline, permits to reveal an original sliding mechanism in this emerged active margin setting.In this complex, the landslides are bounded downslope by deep-incised valleys having directions perpendicular to the sliding directions. Three gas seeps, evidencing upward migration of thermogenic gases to the surface have been discovered in the area. These fluids might be confined at the base of low-permeability siltstone layers, and be overpressured. Such fluid overpressure critically decrease the shear strength of these low-permeability layers and facilitate sliding of the overlying cover. Furthermore, deep fluvial incisions erode downslope buttresses, therefore removing any force resisting sliding at the base of the slope.Analogue modelling show that combined fluid overpressure and incision promote sliding, even on low-angle basal slopes. Normal faults form on the valley flanks, and propagate retrogressively upslope. The extent of the deformation increases with increasing fluid pressure and/or basal slope angle. We have also developed an analytical model of gravity sliding in order to detail the forces in presence and the influence of fluid pressure on the evolution of landslides in the absence of any downslope buttress. The analytical results show, as observed in the experimental models, that sliding might be triggered in this case where low pressures are applied at the base of the potentially mobile cover. The sliding-sheet length increases with increasing fluid pressure.Fluvial incision, leading to the exposure of mechanically weak layers subjected to fluid overpressure and to the removal of the force resisting sliding at the base of the slope, is identified in this study as an important triggering factor for large-scale gravitational instabilities
Delaunay, Antoine. "Les mouvements verticaux de Madagascar (90 - 0 Ma) : une analyse couplée des formes du relief et de l'enregistrement sédimentaire des marges ouest malgaches." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1B006/document.
Full textMadagascar is an Archean to Neoproterozoic continental crust surrounded by transform, oblique and divergent margins: the transform Morondava basin to the west, pounded by the Davie Fracture Zone, and to the north, the divergent Mahajanga Basin connected to the Somali Oceanic Basin. This 1600 km long island is a high axial plateau with elevations from 1200 to 1800m. The top of the plateau corresponds to weathered planation surfaces (etchplains), bounded by more or less high scarps. Such elevation of the high axial plateau imply mantle processes, but the age and cinetic of the uplift is still poorly known. Few studies dealt with anorogenic domains in their entirety from the catchment area, the source, to the downstream depositional system, the sink, none of which is about Madagascar. This work lies on a double approach : it is onshore based on the analysis of the macroforms (planation surfaces, etchplains, pediments) throughout their (i) mapping, (ii) relative dating, (iii) relationships with weathering profiles and (iv) dating by their intersection with preserved sediments and volcanism (lava flow and intrusions). offshore, it is based on the interpretation of a dataset of seismic lines and industrial wells, coupled with refreshed biostratigraphy, in order to (i) identify, date and measure vertical movements of the margins and upstream reliefs. Chronology and mapping of vertical movements were defined on the Morondava margin and compared with the onset of the stepped planation surfaces typical of Madagascar topography. During Upper Cretaceous, the southern part of the island is uplifted, at ~94 Ma. This deformation is sealed by the onset of an undeformed planation surface between 80 and 66 ma. From Paleocene to Upper Eocene (66 to 20 Ma), Madagascar is a flat, low elevated island, surrounded by wide carbonate platforms. The relief is highly weathered with growth of lateritic profiles and silico-clastic influx within the basin is low. During Middle to Upper Miocene is the uplift and doming paroxysm with (1), tilt of the western margin (Morondava), (2) increase of silico-clastic influx from Middle Miocene and (3 the onset of four planation surfaces associated to deformation paroxysms. The end result of this uplift is a convex up shape pattern for the end Cretaceous surface weathered during Eocene times, creating the present-day dome morphology (with a central plateau) of Madagascar. The mechanism of this uplift has to explain a very long wavelength deformation (x1000 km) necessary due to mantle dynamics. The relationships with the other East African domes (Ethiopia, East Africa, South Africa) are discussed
Viel, Vincent. "Analyse spatiale et temporelle des transferts sédimentaires dans les hydrosystèmes normands : Exemple du bassin versant de la Seulles." Phd thesis, Université de Caen, 2012. http://tel.archives-ouvertes.fr/tel-00803223.
Full textTjahjono, Boedi. "Etude géomorphologique du volcan Sunda-Tangkuban Parahu (Java-Indonésie) et évaluation des aléas volcaniques." Clermont-Ferrand 2, 1998. http://www.theses.fr/1998CLF20012.
Full textThe tangkuban parahu volcano (2084 m) is a nested strato-cone which developed in the caldera of the sunda volcano in west java (indonesia). It is situated 17 km north of bandung, a city with 2. 5 millions inhabitants in 1995. Sunda-tangkuban parahu is an andesitic volcano belonging to the medium and high alkaline series and is the sole active volcano in the quaternaire volcanic chain, the so-called sunda complex. The geomorphological evolution of this region is marked by the subsidence of the sunda complex, the debris avalanches along the axis of the sunda complex, the plinian/ignimbritic eruptions of sunda-tangkuban parahu, and the reactivation of the west part of the lembang fault. The first event (0. 51-0. 105 ma) formed the basin and the fault scarps of lembang in the south of the complex, but it folded and thrusted up the northern footslopes, forming the mountain, the basin and the broken fold scarps of tambakan. The second event (between 0. 51 and 0. 105 ma, but after the subsidence) left numerous horseshoe morphologies. The third event (about 105 and 50 ka) created the calderas in the summit and the ignimbritic plateaus around the volcano. By these major eruptions, the most part of this region was covered by ash deposits; they are now deeply weathered. The javanesse equatorial climate allows erosion to incise the deposits in the uplands, forming the deep superimposed valleys in the plateaus, and the aggradation in the lowlands, forming the alluvial plains. The fourth event (about 24 ka) uplifted the old fault scarps that were buried by ash and pumice deposits, forming a new one the so-called composite fault scarps. During the 2 last centuries phreatic eruption has predominated on tangkuban parahu. The hazard and the risk of a future eruption are supposedly from phreatic and phreatomagmatic eruptions, but the recurrence of plinian/ignimbritic eruptions is possible. The pyroclastic flows and surges are considered as the most direct hazard
Ackerer, Julien. "Mécanismes et taux de dénudation d'un bassin versant élémentaire (Strengbach, France) : apport de l'étude couplée des méthodes de datation isotopique (déséquilibres U-Th-Ra, 10Be in situ) et des méthodes de modélisation hydrogéochimique (KIRMAT)." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAH002/document.
Full textIn this PhD work, the combination of the geochemical analytic and isotopic approaches with the modeling approaches has allowed to bring new insights to the understanding of the critical zone and the regolith. Concerning the regolith, this work presents a methodology to perform the analyses of the elemental geochemistry, of the mineralogy, as well as of the U-Th-Ra isotopes and of the in situ 10Be cosmogenic isotope along a single weathering profile. The obtained results highlight the importance of the sampling spatial resolution for an exhaustive interpretation of the U-Th-Ra and of the in situ 10Be data, especially to independently determine the key parameters of the long term regolith production and denudation rates. The two weathering profiles realized in this study furthermore show that (1) the regolith structure is relatively simple on ridge-tops and allows a continuous interpretation of the geochemical and of the mineralogical data and (2) the slope processes tend to increase the spatial heterogeneity of the regolith and of the weathering processes. In addition, the monitoring and the modeling of the surface waters allow to investigate the current weathering processes, and to understand the mechanisms involved in their recent variability. This work shows the relationship that can exist between the modifications recorded at the surface in the soil solutions and the temporal evolution of some chemical properties of the spring waters (pH, calcium concentration). The simulations also allow to understand the weak variability of the global weathering fluxes exported by the springs, in relation with the relative stability of the sodium and of the dissolved silica concentrations over the period 1990-2010. This study also demonstrates the interest of the coupling of methods providing information on the weathering and the erosion processes at different time and space scales, in particular to correctly evaluate the regolith dynamic and to position the present-day functioning of a watershed with respect to its long term evolution
El, Amrani Mohamed. "Evolution morpho-sédimentaire de la basse vallée de l'oued Kert (Maroc nord oriental) depuis 30000 ans : Impact des facteurs naturels et anthropiques." Tours, 2007. http://www.theses.fr/2007TOUR4033.
Full textThe study of the forms and formations in the Kert low valley enable to identify six alluvial units (UF1 to UF6) and three colluvial units (UC1 to UC3). These units formed up of 18 facies and deposited since 30000 years are separated by six incision stages (11 to 16) generating three alluvial terraces (T1 to T3). Upper Pleistocene is mainly marked by sedimentary accretion (UF1a and UF1b), the holocene is characterized by the predominance of the incision (12 to 16) with sedimentary phases of variable duration (UF2 to UF6). This complex morpho-sedimentary evolution would result, for the Holocene, on contrasted bio-climatic trends not appear during upper pleistocene. During the middle holocene temporarily and especially during the upper holocene, human activity deeply modified the geosystem and induced new responses to environment
Mayoral, Alfredo. "Analyse de sensibilité aux forçages anthropo-climatiques des paysages protohistoriques et antiques du plateau volcanique de Corent (Auvergne) et de ses marges par une approche géoarchéologique pluri-indicateurs." Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAL005/document.
Full textThis thesis presents the results of a multi-proxy geoarchaeological study of how anthropogenic forces and climate have shaped the evolution of the landscapes of the plateau of Corent (Auvergne, France) from the Neolithic to Roman period. A detailed geomorphological map of the study area was constructed based on LiDAR data and fieldwork. Two areas were selected for geoarchaeological analysis: i) the Lac du Puy, a small pond located within the archaeological site of the plateau of Corent, and ii) la Narse de la Sauvetat, a larger hydromorphic basin in the calcareous lowlands, at the foot of the southwestern slopes of the plateau.Geoarchaeological survey in the Lac du Puy revealed an expansive group of over one thousand storage pits, dating from the Hallstatt period. The results of fieldwork permitted the construction of a chrono-stratigraphic framework and allowed a reconstruction of the main phases of the hydro-morpho-sedimentary and pedological evolution of the basin. Multi-proxy geoarchaeological analysis of sedimentary cores provided additional information concerning palaeoenvironmental evolution of the Lac du Puy. Anthropogenic impact is clearly discernable throughout five millennia starting in the Neolithic, and is identified as the main driver of the palaeoenvironmental evolution of the basin until its final destruction by human activity.In the lowlands, geomorphological analysis of la Narse de la Sauvetat revealed that the hydromorphic basin is the result of the closure of a palaeovalley by a massive landslide issuing from the southwestern slopes of the Puy de Corent. Geomorphological and stratigraphic evidence indicates that the isolation of the basin likely occurred at the beginning of the Subboreal. Lithostratigraphic analysis was used to reconstruct the main phases of the evolution of the basin from its initial alluvial phase in the late Pleistocene, through to its hydromorphic and palustrine dynamics from the late Neolithic, highlighting the strong palaeoenvironmental potential of its sedimentary record. Multi-proxy geoarchaeological analysis of three sedimentary cores from the basin, combined with results of external malacological analysis, allowed a reconstruction of the palaeoenvironmental evolution of the basin from the late Neolithic to the early Middle Ages.Results obtained from the Lac du Puy and La Narse de la Sauvetat were integrated into the broader morpho-sedimentary system of the plateau and its margins for the period between 3000 BC and 1 AD. The geographic and temporal perspective was then further enlarged through comparison with temperate Western Europe data. The evolution of the socio-environmental system of Corent and southern Limagne was analysed in detail for the first millennium BC. Finally the role of proto-urbanization processes in the forcing of morpho-sedimentary systems is examined, marking their entry into the anthropocene
Principaud, Mélanie. "Morphologie, architecture et dynamique sédimentaire d'une pente carbonatée moderne : le Great Bahama Bank (Bahamas)." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0301/document.
Full textAn analysis of multi-beam echo sounder, sub-bottom profiler (Chirp) and multichannel seismic,highligths the present-day sedimentary dynamics and the Neogene-Quaternary architectural and stratigraphicevolution along the northwestern leeward margin of the Great Bahama Bank.The morpho-bathymetric analysis reveals an aragonite mud-dominated slope, and a broad spectrum ofsedimentary structures, related to various hydrodynamic processes. The density cascading currents associatedwith tidal currents and prevailing easterly winds correspond to the dominant transport mechanisms operatingalong the margin. The Bimini area displays a short and steep slope, stabilized at shelf edge by rimmed reefalbarrier, which constrains the off-bank export of materials.The stratigraphic architecture shows a complex evolution of the slope during the Neogene. The end ofthe Paleogene is marked by a continuous aggrading slope detached from the shelf by a fault escarpment. It passesinto a low angle slope-apron attached to the platform in the Miocene, and ends with an accretionary system witha steepened slope in the Pleistocene. Although the slope deposits are mud-dominated, they show rapid lateralvariations (< 30 km) from South to North throughout the Neogene with the establishment of turbidite aprons,debrite layers and large Mass Transport Complexes. These facies interact since the Langhian with the SantarenDrift which gradually extends and migrates along the slope until today. The maximum extent of the drift occursduring the upper Pliocene and coincides with a global oceanographic reorganization and major climate changesin the northern hemisphere, related to the closure of the Central American Seaway
Quesnel, Florence. "Cartographie numérique en géologie de surface : application aux altérites à silex de l'ouest du Bassin de Paris." Phd thesis, Université de Rouen, 1997. http://tel.archives-ouvertes.fr/tel-00739116.
Full textHaurie, Jean-Louis. "Géodynamique des cirques de la Réunion : implications géotechniques et stabilité des versants." Grenoble 1, 1987. http://www.theses.fr/1987GRE10164.
Full textToone, Julia. "Discontinuités géomorphologiques et organisation des communautés benthiques sur le continuum fluvial de la rivière Drôme." Lyon 3, 2009. https://scd-resnum.univ-lyon3.fr/out/theses/2009_out_toone_j.pdf.
Full textA mixed bedrock-alluvial reach of the River Drôme, France forms the central focus of this thesis. The first part examines long-term changes in channel morphology, and the development of present-day geomorphic zonation. The second part examines the present-day organisation of in-stream macroinvertebrate communities and associations with channel morphology. The study reach is located 200 m downstream from the Béoux sub-catchment, a site chosen for the experimental remobilisation of sediment to rehabilitate degradation along the reach and in downstream parts of the Drôme. The third part evaluates the likely morphological and ecological impacts of this management strategy. Analyses reveal that degradation is a discontinuous process both in time and in space. A large flood in 1978 is seen as the catalyst of zonation. By locking the reach into a particular geometry it imposed substantial spatial discontinuity in the capacity and the propensity of the channel to adjust. Spatial differences in macroinvertebrate community structure reflect spatial differences in channel behaviour. Zone-scale variation in longitudinal, lateral and vertical connectivity, and in particular bed disturbances associated with zone-scale regimes of sediment transfer and storage, control the organization of in-stream fauna. It is considered that the present-day mixed bedrock-alluvial morphology supports a more diverse fauna than historical, alluvial channels. If fluxes of bedload reintroduced to the Drôme are not inferior or excessive to the present-day regimes responsible for maintaining zonation, then this self-regulating dynamic could be maintained. This would also maintain the present-day patterns of macroinvertebrate community structure and so it is concluded that if the reach is secured with a moderate and frequent supply of bedload then the remobilization of sediment is a desirable management strategy
Rabin, Mickael. "Caractérisation de la déformation récente dans une chaine orogénique lente : l'arc du Jura. Approches combinées morphotectonique, géodésique et géophysique." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2008/document.
Full textNo abstract available
Houbart, Anthony. "Évolution géomorphologique quaternaire de la Haute Vallée de l'Elqui : répartition spatio-temporelle des formes, modelés sédimentaires et interprétation paléoenvironnementale : cordillère de l'Elqui (Chili semi-ardie, Norte-Chico)." Thesis, Paris 4, 2014. http://www.theses.fr/2014PA040131.
Full textNorte Chico is a buffer zone having registered Quaternary climatic fluctuations. The preservation of landforms and relief present in the Elqui cordillera, make it a rich geomorphological study area, which may provide answers to many of the assumptions Quaternary calendar climate of the region. Freshness and modeled forms present in the high Andes of Elqui, coupled with the presence of datable organic matter, will allow us to to explain the timing of implementation of the elements of relief. Field indices surveys allow us to highlight a series of processes involving the notion of relay and buffer zones in the sediment transport. Morphogenic crises originally training slope and valley floor currently visible result of a more or less direct answer of the Andean orogen to climatic events, so the results are compared with the results of other studies and in sites close or not our place of study to provide examples and arguments to current hypotheses on the evolution of the Quaternary climatic Norte Chico and multiscale way. The complexity of the implementation of the relief units, requires firstly an explanation of the different orogenic phases and developments morphoclimatic leading to the gradual development of current conditions. Second, the methodology necessary fieldwork and consistent results is defined and explained. A final section presents the synthesis of the series of training implementation valley bottom; the results of this study are also viewed in a broader scientific debate to apprehend the potential provided by the geomorphology in the Quaternary paleoenvironmental study of the Norte Chico as globally