Dissertations / Theses on the topic 'Géochimie minérale'
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Oh, Chun Hyuck. "Géochimie minérale et organique et métallogénie du gisement uranifère de Goesan, bassin d'Ogcheon (Corée)." Orléans, 1986. http://www.theses.fr/1986ORLE3030.
Full textGautier, Quentin. "Cinétiques de précipitation de minéraux carbonatés magnésiens, influence de ligands organiques et conséquences pour la séquestration minérale du CO2." Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1128/document.
Full textForming magnesium carbonate minerals through carbonation of magnesium silicates has been proposed as a safe and durable way to store carbon dioxide, with a possibly high potential to offset anthropogenic CO2 emissions. To date however, chemical reactions involved in this process are facing strong kinetic limitations, which originate in the low reactivity of both Mg-silicates and Mg-carbonates. Numerous studies have focused on the dissolution of Mg-silicates, under the questionable hypothesis that this step limits the whole process. This thesis work focuses instead on the mechanisms and rates of formation of magnesium carbonates, which are the final products of carbonation reactions. The first part of the work is dedicated to studying the influence on magnesite precipitation kinetics of three organic ligands known to accelerate Mg-silicates dissolution rates : oxalate, citrate and EDTA. With help of mixed-flow reactor experiments performed between 100 and 150°C, we show that these ligands significantly reduce magnesite growth rates, through two combined mechanisms: (1) complexation of Mg2+ cations in aqueous solution, which was rigorously estimated from a thermodynamic database established through a critical review of the literature, and (2) adsorption of ligands to a limited number of surface sites, leading to a decrease of the precipitation rate constant. The observed growth inhibition is maximal with citrate. We then used hydrothermal atomic force microscopy to probe the origin of the documented growth inhibition. Our observations show that citrate and oxalate interact with the crystal growth process on magnesite surface, modifying the shape of growth hillocks as well as the step generation frequency through spiral growth. We also show that the ligands adsorb preferentially on different kink-sites, which is probably related to their different structures and chemical properties. We propose that the stronger magnesite growth inhibition caused by citrate is related to a preferential interaction of the ligand with acute steps on the magnesite surface, which limit the spiral growth process through their low advancement rate. The description of these processes with an empirical rate law allows performing simple numerical simulations of forsterite carbonatation at 120°C in the presence of the ligands. We thus demonstrate that the use of the investigated ligands would clearly be detrimental to the carbonation of forsterite. The third and last part of this work deals with hydromagnesite solubility and growth kinetics between 25 and 75°C. The obtained results show that hydromagnesite growth rates largely exceed magnesite rates at comparable chemical affinity, while the activation energy of the process is much smaller than for magnesite. This original kinetic dataset thus confirms the long-standing hypothesis that Mg2+ dehydration is the rate-limiting step for Mg-carbonate precipitation from aqueous solution. However, due to its higher solubility, hydromagnesite may grow more quickly than magnesite only at low temperature and alkaline pH. Thus, it may not provide a solution to the sluggish precipitation kinetics of magnesite during Mg-silicates carbonation
Caillaud, Alexis. "Dépôts organiques en milieu marin : les facteurs clés des bassins hémipélagiques : le Mésozoïque du Bassin du Sud-Est de la France." Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1R012/document.
Full textThe goal of this work is to study the sedimentology of organic deposits in a hemipelagic basin (Mesozoic deposits of the S-E France Basin) in order to understand the processes responsible for transport and preservation of organic matter (OM), as well as its distribution in various sedimentary settings. The results demonstrate that there is no relationship between the organic content and the grain size of the terrigenous fraction or the mineralogy of the clay fraction. Turbidites are present in a particular organic level, but they did not convey terrestrial OM in the basin; on the contrary, they had a negative role upon the preservation of the organic content. Terrestrial OM is observed in some organic levels, but not related to gravity deposits, meaning that terrestrial OM can be transported to the distal marine domain without necessarily involving gravity processes. There is no clear link between the nature of the OM and the place of the deposits in the 3rd order stratigraphic sequences. The major contribution of the present work concerns the multi-factor approach to the sedimentology of OM in the marine domain. For a constantly low to normal marine primary productivity, it was highlighted the role of 3 key factors for the formation of organic deposits in the hemipelagic basin: the sedimentation rate, the intrinsic nature of OM, and the basin oxygenation conditions. The organic levels the richest in OM are the global anoxic events, which show that anoxia is the factor allowing the strongest organic accumulations in this type of sedimentary basin
Dufaud, Fabien. "Etude expérimentale des réactions de carbonatation minérale du C02 dans les roches basiques et ultrabasiques." Paris, Institut de physique du globe, 2006. http://www.theses.fr/2006GLOB0010.
Full textMineral storage of carbon dioxide in the form of geologically stable carbonates is an option for mitigating the atmospheric CO2 increase. The purpose of this thesis has been to study carbonate formation in basic and ultrabasic rocks under high pressure high temperature possible CO2 injection conditions. First, data on siderite dissolution, a reaction limiting CO2 mineral storage, have been acquired by x-ray absorption spectroscopy under high pressures and high temperatures. A dissolution rate law, an activation energy and solution speciation data are given. These experiments have allowed to test the potential for these kinds of studies of batch microreactors mounted on synchrotron beamlines. Then, a laboratory experiment aimed at mimicking CO2 injection in basic and ultrabasic rocks at 90°C and 280 bar CO2 pressure is shown. Carbonatation by dissolution/precipitation of peridotites, basalts and serpentinites yields zoned siderites/ankerites/magnesites with mineral storage rates, depending on the substrate rock, of few percents per year. Finally, in order to study cases with high carbonatation rates, an experimental study on olivines, pyroxenes and serpentines has been relalized at 400-500°C and 1-1. 7 kbar. Mineral storage rates of several percents per hour have been measured. The importances of water fugacities and salinities have been evidenced and a stoichiometric coupling between carbonate production and olivine serpentinization has been shown. A methodology based on carbon isotopic analyses has been developed for establishing mass balances. It suggests that small but significant quantities of reduced carbon are formed in these experiments
Gautier, Quentin, and Quentin Gautier. "Cinétiques de précipitation de minéraux carbonatés magnésiens, influence de ligands organiques et conséquences pour la séquestration minérale du CO2." Phd thesis, Université Paris-Est, 2012. http://pastel.archives-ouvertes.fr/pastel-00806512.
Full textCaillaud, Alexis. "Dépôts organiques en milieu marin : les facteurs clés des bassins hémipélagiques : le Mésozoïque du Bassin du Sud-Est de la France." Electronic Thesis or Diss., Université de Lille (2018-2021), 2018. http://www.theses.fr/2018LILUR012.
Full textThe goal of this work is to study the sedimentology of organic deposits in a hemipelagic basin (Mesozoic deposits of the S-E France Basin) in order to understand the processes responsible for transport and preservation of organic matter (OM), as well as its distribution in various sedimentary settings. The results demonstrate that there is no relationship between the organic content and the grain size of the terrigenous fraction or the mineralogy of the clay fraction. Turbidites are present in a particular organic level, but they did not convey terrestrial OM in the basin; on the contrary, they had a negative role upon the preservation of the organic content. Terrestrial OM is observed in some organic levels, but not related to gravity deposits, meaning that terrestrial OM can be transported to the distal marine domain without necessarily involving gravity processes. There is no clear link between the nature of the OM and the place of the deposits in the 3rd order stratigraphic sequences. The major contribution of the present work concerns the multi-factor approach to the sedimentology of OM in the marine domain. For a constantly low to normal marine primary productivity, it was highlighted the role of 3 key factors for the formation of organic deposits in the hemipelagic basin: the sedimentation rate, the intrinsic nature of OM, and the basin oxygenation conditions. The organic levels the richest in OM are the global anoxic events, which show that anoxia is the factor allowing the strongest organic accumulations in this type of sedimentary basin
OGIER, SYLVIE. "Diagenèse précoce en domaine lacustre : étude des composés minéraux et organiques des sédiments récents du lac d'Aydat (Puy de Dôme, France)." Phd thesis, Université d'Orléans, 1999. http://tel.archives-ouvertes.fr/tel-00002273.
Full textMonneron-Gyurits, Matthias. "Bioaccessibilité et spéciation des métaux/métalloides sur d’anciens sites industriels en vue d’une gestion intégrée et d’une refonctionnalisation." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0062.
Full textToday, the management of polluted sites and soils appears to be a major challenge for environmental and health policies. To do this, decision support tools must be developed and validated to facilitate the identification and understanding of the risks involved. In this context, the objective of this study is to improve knowledge of the links between the nature of contaminants, their geochemical behavior, the nature of carrier phases and bioaccessibility. Ultimately, this understanding will lead to a more specific assessment of the environmental and health risks attributable to them, and to a more coherent remediation. To do this, two contaminated sites with different typologies (mining vs. industrial) were studied but with similar contamination (As, Pb, Zn and Cd). After a representative sampling in accordance with the type of site and its geomorphology, a fine physico-chemical characterization was carried out on each sample before determining their environmental and physiological stability (bioaccessibility). The coupling with environmental mineralogy made possible to explain the behavior of the elements in the various environments. In a second step, in order to overcome the constraints of a complex environment such as the soil and to define the real impact of each bearing phase on the risks, pure phases were synthesized and subjected to the same tests as the natural samples. A return to the solid is then systematically carried out, highlighting the mineralogical changes undergone by the sample. Mixtures have also been made to understand and better understand the cocktail effects of metallic and metalloid elements. This integrated, multi-analytical and multi-scale approach is then the first step in a long process of understanding and predicting risks based on geochemistry and environmental mineralogy coupling
Maréchal, Benoît. "Caractérisation et interprétation de la variabilité chimique et minéralogique des grès réservoirs.Implications pour la modélisation numérique de la diagenèse minérale des grès du Ravenscar Group (Yorkshire, Royaume-Uni)." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2000. http://tel.archives-ouvertes.fr/tel-00089197.
Full textCes descriptions sédimentologiques ne prennent pas en compte les caractères pétrographiques, minéralogiques ou géochimiques qui permettraient pourtant d'attribuer des causes directes, primaires ou secondaires, aux variations de porosité et de perméabilité rencontrées dans les roches. De plus, depuis quelques années, la diagenèse minérale, souvent à l'origine de ces variations, fait l'objet d'une modélisation déterministe qui s'appuie sur les processus physiques et chimiques mis en œuvre. Des logiciels de plus en plus performants permettent ainsi de réaliser des simulations destinées à proposer des bilans géochimiques variés qu'il est nécessaire de valider par des observations de terrain.
Cette thèse a pour objectif, d'une part, de compléter les études sédimentologiques par l'acquisition et l'analyse de données géochimiques et, d'autre part, de mieux comprendre la diagenèse des grès réservoirs en associant la géochimie à la modélisation numérique.
Deux formations géologiques, analogues de réservoirs exploités, ont servi de support à cette étude : les grès fluviodeltaïques du Ravenscar Group (Jurassique Moyen, côtes du Yorkshire, Royaume-Uni) et les Grès turbiditiques d'Annot (Eocène-Oligocène, Bassin du Sud-Est, France). L'échantillonnage a été réalisé afin d'apprécier la variabilité verticale et latérale de composition à diverses échelles (centimétrique à hectométrique) aussi bien entre faciès sédimentaires qu'au sein d'un même niveau lithostratigraphique.
L'étude géochimique montre que les faciès sont caractérisés par leur gamme de composition chimique ainsi que par leur style de variabilité élémentaire. Elle permet également de mieux comprendre la répartition des minéraux et des éléments au sein de la roche.
Ainsi, dans certains faciès, le tri sédimentaire entre les petits minéraux lourds et le reste de la roche (entrainment sorting) engendre des variations de teneur importantes pour les éléments portés par ces différentes classes de particules détritiques (Zr, Cr, Th, etc. pour les minéraux lourds ; Al, Na, K, etc. pour la fraction élastique). Des caractéristiques chimiques propres à chacune de ces populations de minéraux, valables à une échelle verticale de plusieurs mètres, peuvent alors être définies. Certaines d'entre elles, relatives aux éléments immobiles, permettent d'identifier des variations dans l'alimentation détritique. Une ségrégation s'opère également au sein de la fraction élastique entre les particules les plus grosses, dont la nature dépend de la maturité du grès, et les autres grains lors du dépôt.
Deux transformations diagénétiques majeures, à savoir la kaolinitisation et l'albitisation des feldspaths, sont également à l'origine de la distribution particulière des compositions chimiques de la fraction alumineuse des grès du Ravenscar Group.
Ce dernier point a été utilisé pour tester et valider la modélisation numérique de la diagenèse des grès du Ravenscar Group à l'aide du code numérique DIAPHORE de l'Institut Français du Pétrole. La néoformation de kaolinite apparaît alors possible dans la gamme de température 25-80°C, quel que soit le type d'eau superficielle considéré. La précipitation des argiles est induite par la présence et la circulation d'une eau en déséquilibre avec le réservoir gréseux, entraînant la dissolution successive des feldspaths. L'albitisation des feldspaths plagioclases s'effectue à faible température et dépend assez peu du type d'eau injectée. Enfin, l'albitisation des feldspaths potassiques est plus délicate à réaliser et n'est efficace que pour des eaux marines ou saumâtres à des températures supérieures à 50°C, et circulant dans un réservoir soumis à un gradient de température. Les simulations confirment donc l'importance de la perméabilité et de la circulation des fluides dans la diagenèse des aluminosilicates.
Les variations de composition chimique de la fraction alumineuse des grès du Ravenscar Group sont reproduites dans les simulations. Les conditions nécessaires aux transformations sont particulières mais compatibles avec le contexte géologique des grès étudiés. Les principales transformations diagénétiques, indépendantes, nécessitent alors plusieurs épisodes de circulation d'eau pour rendre compte de la diversité des compositions chimiques et minérales observées.
Les travaux menés dans le cadre de cette thèse laissent à penser que l'on pourrait intégrer plus systématiquement l'approche géochimique dans les études de réservoir.
Chanvry, Emmanuelle. "Caractérisation et facteurs de contrôle des distributions minéralogiques du Bassin Piggyback de Graus-Tremp-Ainsa (Espagne), à l’Eocène Inférieur." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEM034/document.
Full textWe develop here a methodology to integrate the mineralogical record into a high resolution sequence stratigraphic framework realized in the Early Eocene Graus-Tremp-Ainsa Basin. Coupling stratigraphic with geochemical and mineralogical approaches allows us to unravel the effects of tectonics, climate, eustasy and diagenesis on basin architecture and mineralogy. An automated computed mineralogy is derived from whole-rock geochemical data, and calibrated against direct mineral quantifications (petrography, DRX, Qemscan, microprobe). It provides a basinscale view of mineral distribution, irrespective of the lithology. Diagenetic overprint and hydrodynamic sorting effects are evaluated first, then primary mineral distributions are reconstructed and ascribed to different types of sediment sources.We show that, at the million-year timescale, tectonics shape the architecture and the mineralogy of the deposits. Spatially distributed diagenesis and temporal and spatial changes in sediment sources reflect the competing effects of intrabasinal tectonics (local thrust displacements) versus basinscale flexural subsidence linked to the orogen uplift and loading. Tectonically-driven changes are also sensitive to higher frequency (100 ky) anomalic climatic events (PETM, ELMO, X-EVENT) leaving a mineralogical signal in clay fractions and environment deposits succession.The basinscale evolution displays two contrasting stages. During the Ilerdian to the lower Cuisian, a mixed carbonate ramp evolves to a set of deltaic fans of Northern (Pyrenean orogen) provenance delivering plutonic-dominated materials. Then, during the lower/mid Cuisian, they are overprinted by a large fluvial and deltaic system bringing recycled carbonates and siliciclastics sourced in the emerging eastern to southern sedimentary thrust sheets. Later on, the propagation of the Montsec thrust and its lateral ramp decouples the uplifted Graus-Tremp basin from the strongly subsiding Ainsa basin. These different subsidizing schemes are underlined diagenetic overprints diverge, with an extensive kaolinisation of the uppermost units in the Graus-Tremp Basin driven by meteoric fluid circulations, and a severe albitisation of sandstones in the Ainsa basin, coupled with the illitisation of smectites in the lutites and caused by deep basinal fluids
Brigaud, Benjamin. "Influence du contexte sédimentaire et de la diagenèse sur les propriétés pétrophysiques du Dogger calcaire de l'Est du Bassin de Paris." Phd thesis, Université de Bourgogne, 2009. http://tel.archives-ouvertes.fr/tel-00503241.
Full textOudin, Elisabeth. "Les sulfures océaniques : étude minéralogique et géochimique des processus hydrothermaux actuels et fossiles." Toulouse 3, 1991. http://www.theses.fr/1991TOU30090.
Full textMichaux, Laurent. "Altérations supergènes et hydrothermales des roches basiques et ultrabasiques : pétrologie, géochimie et modélisations thermodynamiques." Aix-Marseille 3, 1988. http://www.theses.fr/1988AIX30058.
Full textAncellin, Marie-Anne. "Origine de la diversité géochimique des magmas équatoriens : de l'arc au minéral." Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC083/document.
Full textArc lavas display a complex geochemistry resulting from the heterogeneity of primitive magmas and their transformation within the crust. Identifying primitive magma compositions in continental arcs is challenging because continental crust is thick and acts as a mechanical and chemical filter for ascending magmas. This issue is particularly criticial in Ecuador owing to the great thickness of the continental crust (≈ 50-60 km) and the scarcity of erupted primitive magmas. This thesis aims to determine the composition of primitive silicate melts in the Ecuadorian arc, on the scale of the whole arc, as well as on the scale of two volcanic edifices: the Pichincha and the Tungurahua. This study also intends to better understand how those primitive melts evolve during their journey through the continental crust. In Ecuador, slab dip, relief and age change from north to south. Hence, the first part of the PhD focuses on the influence of those parameters on magma geochemistry, through a whole rock study covering the entire arc. It confirms the across-arc geochemical variations described by previous studies: an increase of incompatible element contents and a decrease of fluid-mobile over fluid-immobile element ratios from west to east. We identify along-arc geochemical variations in the volcanic front (e.g. Ba/Th), related to the changing nature of metasomatic fluids, which are aqueous fluids at the centre of the arc (around 0.5°S) and silicate melts to the north and probably to the south. This change may be due to the subduction of a younger and warmer oceanic crust to the north, which might promote slab melting. Lastly, it seems that deep crustal contamination increases towards the south of the volcanic front. Secondly, volcanic products emitted for the last 3,000 years at Tungurahua are studied. On this timescale, the tectonic parameters of the first study are constant. This work details the role of continental crust in the production of differentiated magmas, which are systematically associated with more explosive eruptions. We conclude that andesites have heterogeneous isotopic compositions (206Pb/204Pb = 18.834 - 19.038), acquired at depth (mantle or deep crust), that homogeneize through andesite differentiation to dacite (206Pb/204Pb = 18.965 - 19.030) by fractional crystallization and assimilation of the local upper crust (7-9 %). Lastly, the third part of the PhD focuses on the heterogeneity of primitive magmas. We study individual minerals from Pichincha and Tungurahua volcanoes and show that most minerals are in disequilibrium with their host rock (up to 8,600 ppm for 206Pb/204Pb). The diversity of Pichincha minerals allows the identification of mantle melt diversity (206Pb/204Pb = 18.816 - 19.007), with compositions forming a tight trend in Pb-Pb isotope spaces. As for Tungurahua whole rocks, crustal assimilation erases the diversity of primitive melt isotope signatures through differentiation, so that primitive melt signatures are not preserved in whole rock samples. At Tungurahua, individual minerals show that the heterogeneity of isotope compositions is acquired at depth. The analysis of two olivine fractions reveals the existence of a radiogenic signature in the mantle source of Tungurahua volcano, interpreted as the presence of delaminated crust within the mantle beneath its edifice. Finally, olivine fractions from seven Ecuadorian volcanoes highlight the fact that no unique primitive signature exists in the arc. Isotopic heterogeneity is entirely inherited from the mantle (206Pb/204Pb = 18.583 - 19.000). Primitive melt compositions are then shifted by continental crust contamination which, in most cases, results in more radiogenic signatures
Ben, Baccar Mohamed Ennaceur. "Modélisation géochimique de la diagénèse minérale et de ses conséquences sur la porosité des réservoirs." Strasbourg 1, 1992. http://www.theses.fr/1992STR1A004.
Full textAlmeida, de Carvalho Ancilla Maria. "Evolution of the Early Cretaceous, South-Atlantic pre-salt lacustrine systems : Insights from Stratigraphic Forward and Geochemical Modeling." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS590.
Full textThe lacustrine carbonate rocks of the Barra Velha Formation (BVF), Santos Basin, present distinct composition and texture, with superimposed sedimentary and diagenetic heterogeneities, forming complex reservoirs. To better understand and predict lateral and vertical heterogeneities of the carbonate reservoirs of Santos Basin, we conduct a multidisciplinary approach, integrating sedimentological-diagenetic analyses, stratigraphic forward (process-based) modeling, and geochemical modeling. From a multiscale dataset of a field localized in the Outer High of the Santos Basin, we (1) characterized the spatial and stratigraphic distribution of the different facies and diagenetic phases and their main controlling factors, (2) evaluated the conceptual model proposed and provide the initial conditions for fluid-rock interaction model, using stratigraphic forward modeling (SFM) (3) investigated the ideal physicochemical conditions and basin fluid circulation patterns ruling the diagenetic alterations observed in the study area. The data analysis performed in this study highlights the spatial and temporal distribution of different types of Mg-clay, the main diagenetic products, and their association with different facies. The stratigraphic variations in Mg-clay distribution indicate an influence of the lake water chemistry. Furthermore, the Mg-clay alteration pattern and its diagenetic features suggest a strong control of the structural setting. The spatial and stratigraphic distribution of sedimentological and diagenetic heterogeneities indicate that the lake water’s first-order hydrochemical evolution drove the major depositional and diagenetic aspects, modulated by local factors, which enhanced the diagenetic imprint. Three main characteristics mark the lake water hydrochemical variation: an initial stage associated with a higher input of detrital content, an intermediary phase marked by higher evaporative conditions, and a final stage characterized by fluctuations of the evaporative conditions with a lower detrital contribution. In the second part of the study, we propose a stratigraphic forward model based on the depositional conceptual model and the evaluation of large-scale constraints, like subsidence and lake-level variations. The model also addresses the lake-level variations relying on the hydrologic water balance between precipitation and evaporation rate and provides insights into the evolution of hydrological zones. Through the process-based model, we propose a lateral and vertical grid of facies used to parametrize the reactive transport modeling. In the third part of the study, a series of geochemical calculations were used to estimate the diagenetic potential of different solute sources and the main paleoenvironmental controls on diagenetic modifications. The calculations show that the pH fluctuation is the main factor impacting the Mg-clay preservation, followed by the diagenetic fluids' Mg/Ca and Mg/Si ratios, and emphasize the role of pCO2 in the diagenetic alteration. In addition, the models point out the ability of different Mg-clay types to generate distinctive amounts of diagenetic products. Finally, we explore diagenetic scenarios on the BVF sag phase through reactive transport modeling, focusing on the dolomitization, silicification, and dissolution processes and addressing the impact of regional versus local fluid circulation on diagenetic alteration. The initial facies heterogeneities, intrinsically related to the depositional characteristics, have a crucial role in the evolution of the diagenetic process. The results also highlight the preferential pathways of fluid circulation and diagenetic alteration associated with Mg-clay-rich layers and facies with higher permeability alternation. The multidisciplinary approach provides a spatial view of the interplay between rock properties and possible fluid circulation patterns in the basin
Grimaud, Daniel. "Etude géochimique et géothermométrique des eaux thermominérales des Alpes françaises." Paris 7, 1987. http://www.theses.fr/1987PA077115.
Full textRose, Estelle. "Géochimie isotopique du bore dans les cycles supergènes d'altération." Vandoeuvre-les-Nancy, INPL, 1999. http://docnum.univ-lorraine.fr/public/INPL_T_1999_ROSE_E.pdf.
Full textLarge variations in boron (B) isotopic compositions were found in river waters, clay minerals from sediments and soils, rain waters, and snow. For this study, a new analytical method was developed to analyse boron isotopes in natural samples with low boron content (sometimes less than 1 ppb). Boron isotopie compositions of river waters, which are among the first to be measured, are highly variable ( ≈35%o). These variations suggest that boron is a potential tracer of weathering processes. Variations in boron isotopic compositions due to silicate alteration are sensitive to the extent of dissolution (total or partial) and to the pH of the soil where secondary minerais are formed. Large changes in boron isotopic compositions found in the Gange and the Brahmapoutre rivers between the monsoon and the dry seasons (≈ 15%o) reveal the extreme heterogeneity of inputs to the ocean, which has to be considered to understand the processes regulating the B isotopic composition of seawater. Boron isotopic compositions of clay minerals (<0. 1μm et <2μLm) from Himalayan sediments and soils display also large variations. However, it is possible to discriminate between kaolinite rich clays, which display typical low Il B enrichments, and smectiterich clays, which are usually enriched in ¹¹B. These differences are enhanced by the monsoon. The newly measured boron isotopic compositions in rain waters and snows unravel information on the boron isotopic composition of the atmosphere. Experiments performed in the laboratory to mimic the evaporation of seawater showed that it is possible to reproduce concentrations and isotopic compositions of natural rain waters
Noack, Yves. "Differenciation entre altération météorique et altération hydrothermale : applications aux minéraux ubiquistes : talc, chlorites, serpentines; pétrologie, minéralogie, géochimie." Poitiers, 1985. http://www.theses.fr/1985POIT2021.
Full textBonfils, Benjamin. "Mécanismes et verrous de la carbonatation minérale du CO2 en voie aqueuse." Phd thesis, Toulouse, INPT, 2012. http://oatao.univ-toulouse.fr/7920/1/bonfils_partie_1_sur_2.pdf.
Full textGallino, Stéphanie. "Hydrogéologie, géochimie et modélisation hydrodynamique-thermique d'un système thermo-minéral associé à un contact structural alpin (Aix-les-Bains - Savoie)." Chambéry, 2007. http://www.theses.fr/2007CHAMS039.
Full textThis study, based on a interdisciplinary approach, re-examines the circulation model of the thermal and mineral waters from Aix-les-Bains for drilling a rescue well. A 3D model, built from geological and geophysical data, shows that two major faults (N135 and N065°E) individualize the three studied sites (Thermes Nationaux, Thermes de Marlioz, Raphy Saint Simon). Hydrochemical data suggest a millennial residence time for the waters, a major role of the thrust in the main mineralisation (Na, K, C1, SO4), a strong link between the chemical characteristics of each site and the exchange ionic processes evolution during the upwelling and a mixing with the surface waters in the final part of the upwelling. The mineral waters have a different sulphate origin compared with the thermal waters (pyrite or triassic gypsum dissolution). The hydrodynamical data demonstrates that (i) the Valanginian and the Kimmeridgian limestones represent the infiltration zones, (ii) the starting of the well exploitation catches deep flows towards the springs and (iii) the dispersive role of the urgonian karst in the final upwelling. The coupled hydrodynamical-thermical model evidences the cooling of the thermal waters in deep depth. The current temperatures are induced by an un-steady state flow since the last deglaciation. An evolution in time and space of the hydraulic conductivities (initiation and evolution of the karst), and/or a late starting of the hydrothermal system (tills leaching, neotectonic event) is then needed
Ddani, Mohamed. "Origine de la diversité de minéraux smectitiques des bentonites dans un contexte volcanique et volcano-sédimentaire : Rif Nord Oriental (Maroc)." Poitiers, 2004. http://www.theses.fr/2004POIT2325.
Full textA great number of bentonite deposits have been discovered around the Gourougou vocanic massif (northeastern Morocco). Some of them have been formed by hydrothermal alteration (Providencia, Tribia) while the others are formed in marine, lagoonal or lacustrine environments (Ibourhardayn, Moulay Rachid, Melg el Ouidan). The crystallochemical properties of the smectites vary with the alteration conditions (temperature, composition of the fluids). Beidellites are formed in hydrothermal conditions while montmorillonite is formed in sea water of fresh water. The bentonite formed by the alteration of pyroclastic deposits in the vicinity of the volcano are composed of a beidelle-montmorillonite mixture. The formation of beidellite or montmorillonite is controlled by the amount of magnesium available in the alteration system (volcanic glass and solutions). The beidellites are formed in open hydrothermal systems where the solutions are strongly Mg-depleted. The Mg content of the volcanic glass decreases by leaching leading to the precipitation of an Al-rich smectite. On the opposite, the montmorillonites are formed in closed systems. The magnesium provided either by the solution (sea water) or by the volcanic glass itself is incorporated in the neoformed smectites. Consequently, different bentonite types may derive from similar rhyolitic glass according to the local alteration conditions. The rheological properties do not depend directly from the beidellite or montmorillonite crystal structure of the smectites. Other parameters such as the presence of salts and the interlayer cations are more important
Bongiolo, Everton Marques. "Intégration de données minéralogiques, isotopes stables (O, H) et porosité de roche (14C-PMMA) dans la reconnaissance de l'évolution de l'altération dans le système hydrothermal de Lavras do Sul-RS, Brésil." Poitiers, 2006. http://www.theses.fr/2006POIT2334.
Full textAntonelli, Fabrizio. "Caractérisation pétrographique et géochimique des marbres griottes (ou cipollino mandolato) des Pyrénées centrales : étude archéométrique de pièces archéologiques des époques gallo-romaine et médiévale." Tours, 1997. http://www.theses.fr/1997TOUR4021.
Full textCaillaud, Jacinthe. "Localisation et distribution des Eléments Traces Métalliques (ETM) naturels au cours de l'altération supergène d'une serpentinite : rôle des microsystèmes et des minéraux argileux associés." Poitiers, 2003. http://www.theses.fr/2003POIT2345.
Full textThe pedogeochemical background from a serpentinite was studied at the scales of a weathering profile and its related weathering microsystems and clay minerals. The serpentinite weathering is rapid and intense and show early magnesium leaching from serpentine minerals. A detailed mineralogical study indicates that rock weathering is controled by three microsystems : the primary plasma (weathering sequences), secondary plasma (homogeneization of clay mineralogy and oxides) and the fissural systems. Chemical potential of magnesium in solution appears to control these microsystems ; the decreasing of such potential will generate, from bottom to top, an evolutive sequence from magnesian trioctahedral to dioctahedral, iron rich clay minerals, and then aluminous clay minerals. MTE trapped in primary mineral are relatively concentrated in secondary phases from weathering levels. When compared to their concentrations in rock, chromium, nickel, zinc and copper are strongly enriched in the clay minerals from lower alteration levels. In contrary, upper alteration levels show decreasing MTE concentrations. Cobalt and manganese behaviours are more independant on the clay phases and mainly trapped into oxy-hydroxides. However, manganese can be found as exchangeable state in these upper levels. The secondary oxy-hydroxides generated by iron segregation at the top of the profile are the newly MTE bearing phases to the detriment of clay minerals
Pinto, Lincoñir Luisa del Carmen. "Traçage de l'érosion cénézoi͏̈que des Andes centrales à l'aide de la minéralogie et géochimie des sédiments (Nord du Chili et Nord-Ouest de la Bolivie)." Toulouse 3, 2003. http://www.theses.fr/2003TOU30034.
Full textLa evolución tectónica y orográfica del oroclino boliviano (en los Andes Centrales) constituye uno de los problemas para comprender la evolución de los Andes. El análisis de la composición mineralógica y geoquímica de los sedimentos almacenados en las cuencas de este segmento de la de la cadena andina entre Arica (norte de Chile) y Rurrenabaque (noroeste de Bolivia) permite reconstituir la evolución de la exhumación de los diferentes compartimentos tectónicos y su evolución durante el Cenozoico. Los resultados del análisis de minerales pesados contenidos en los sedimentos cenozoicos, de su geoquímica y de la isotopía de Sr-Nd confirman que el relieve de la Cordillera Occidental y (proto-)Cordillera Oriental se desarrollaron bastante temprano. .
Munier, Thomas. "Évolution des conditions d’altération et des paléoclimats au cours de l'intervalle Albien-Santonien (113-83 Ma) : apports des minéraux argileux et de la géochimie." Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS156.pdf.
Full textThe Albian-Santonian interval (~113-83 Ma) is a key period in Cretaceous history. This interval is characterised by a high seafloor spreading rate, related to the breakup of Pangea, and by a significant activity of large igneous provinces, which generate an increase in pCO2 (Arthur et al., 1985). These conditions lead to a progressive temperature increase until the mid-Cretaceous thermal maximum, recorded at the Cenomanian/Turonian boundary (~94 Ma). This latter is followed from the late Turonian by a decline in temperature and pCO2 (Linnert et al., 2014; Wang et al., 2014). A decrease of volcanic activity, an increase of carbonate production, and an enhanced organic carbon storage during the anoxic oceanic event OAE 2 (Cenomanian-Turonian boundary) are frequently cited to explain the pCO2 decline. However, silicate weathering can also be involved as a triggered mechanism for this decrease. The analyse of new boreholes, drilled during the IODP Leg 369 on the southern and southwestern margins of Australia, coupled with some old boreholes of the ODP Legs 122 and 123 on the northwestern margin, allowed us to investigate the evolution of weathering conditions during this interval at the middle and high latitudes in a poorly studied sector. A detailed work, based on clay mineralogy, has been done on six sites located in the Great Bay Basin (Site U1512), in the Mentelle Basin (sites U1513 & U1516), in the Carnarvon Basin (sites 763 & 766) and the Argo Abyssal Plain (Site 765), respectively. For 3 sites (U1512, U1513 and 763), these studies have been completed by SEM and TEM observations and geochemical analyses (Sr and Nd isotopic ratios and concentrations of major & trace elements). These new data have been compared to the several studies, already done in the Atlantic Ocean and in the peri-Tethyan domain. During the Albian-Turonian interval, the clay mineral assemblages are characterised by an increase in smectite proportions, observed over all the studied regions. This increase results from a combination of global and local parameters. The tectonic stabilisation of the African and North American margins reduces the physical weathering, which leads to a decrease in illite and chlorite proportions, and permits the implementation of pedogenetic processes, which favours the formation of smectites. The preferential weathering of volcanic rocks from the end of the Cenomanian, highlighted by Sr and Nd isotopic measurements on some sites of Australia (U1513) or Africa (959) margins, also results in a relative increase of smectites. Finally, the sea level rise, recorded from the Albian to the Lower Turonian and associated with an enrichment in smectites, highlights the influence of the differential settling process on clay assemblages. The Cenomanian-Turonian interval, characterised by an increase in the proportions of kaolinites at the low and middle latitudes of the Northern Hemisphere, is interpreted as marked by more hydrolysing conditions. These kaolinites are present only in sectors, where tectonic was active at the end of the Early Cretaceous (Aptian-Albian). Thus, despite a climate favourable to their formation, the absence of kaolinites in favour of smectites in the Southern Hemisphere characterizes the influence of topography and good drainage conditions to form these minerals. The Albian-Santonian interval is thus characterised by an increase in chemical weathering that was maximal at the mid-Cretaceous thermal maximum. Nevertheless, this increase in hydrolysing conditions, associated to the denudation of the continental landmasses, seems to be insufficient to cause the pCO2 decrease during this thermal maximum. It appears then, despite a climate favourable for hydrolysis, high sea level and flattening of the continental masses prevent the chemical weathering of silicates which cannot regulate pCO2
Oyarzun, Muñoz Jorge. "La métallogénie andine : cadre géologique, pétrologique et géochimique et essai d'interprétation." Paris 11, 1985. http://www.theses.fr/1985PA112092.
Full textThe Andean metallogenesis is explained through the analysis of geological, petrological and geochemical aspects of the belt. They include a continuous and abundant production of calc-alkaline magmas, a dominance of vertical tectonics in pericontinental “ensialic” basins, and episodes of accretion of oceanic crust. These aspects, as the presence of metallic belts corresponding to the future “Andean” metallogenic provinces, are well expressed since Palaeozoic times. An important part of the Andean mineralization is directly related to the calc-alkaline magmatism. Also, the metallic zoning of the Andes, which is normal to the belt, may be explained in terms of the oxidation conditions of calc-alkalyne magmas; and the regional abundance of “anionic” elements and complexes (partly controlled by these conditions, f. I. : S²⁻ / S⁴⁺). However, palaeogeographic evolution has also contributed to the syngenetic-or epigenetic-deposit of some metals of the belt, such as Pb, Zn and Ag. The re-cycling of magmatic material (comparable to the process inferred in some oceanic island arcs) is probably responsible for a metallogenical “maturing” of the belt, which culminated in the Tertiary
Blaise, Bertrand. "Sédimentation et paléoenvironnements plio-quaternaires sur la bordure Nord-Est de l'Océan Pacifique." Lille 1, 1985. http://www.theses.fr/1985LIL10119.
Full textLopez, Olivier. "Aspects mécanistiques de la réaction de précipitation de la calcite et mouvements de fluide supercritique dans une matrice calcitique : implications au stockage minéral du C02." Paris, Institut de physique du globe, 2006. http://www.theses.fr/2006GLOB0018.
Full textBouvier, Pierre. "Les gabbro-diorites du domaine de Boussac : pétrographie, minéralogie, géochimie : relations avec le magmatisme acide du domaine de la Marche-Guéret." Paris 11, 1985. http://www.theses.fr/1985PA112353.
Full textThe N-W Franch Massif Central consists of three main structural domains, from North to South : the Plateau d'Aigurande, the Boussac and the Marche-Guéret domains. The Plateau d'Aigurande is made up of four overthrusted units, differing by their metamorphic and tectonic evolutions, and intruded by Westphalien granites. The plutonic activity has taken place during the last thrusting event. The Boussac domain, magmatic rocks display a significant evolution, with a calc-alcaline gabbro-diorite series showing potassic affinity. Gabbro-diorite rocks have intruded migmatitic and gneissic series, during the middle to upper Devonian main metamorphic event. The initial chemical composition have been locally disturbed by late fluids contamination. The Marche-Guéret domain consists in three granitic clusters : the Guéret granites (356 MY) which show alumino-potassic affinitys ; the Marche deformed granites (325 MY) and the Marche post-tectonic granites (300 MY). These last two clusters are made up of leucogranites and biotite granites of anatectic origin
Amal, Youssef. "Analyse mathématique et numérique de modèles de germination et de croissance de particules minérales dans un contexte de simulation géochimique au contact de solutions aqueuses." Université Louis Pasteur (Strasbourg) (1971-2008), 2008. http://www.theses.fr/2008STR13126.
Full textMost geochemical models considering the interactions between rocks ans solutions include thermodynamic equilibrium relationships between solid phases and aqueous solutions, and address the kinetic problems by introducing rates of growth and dissolution, but usually they describe the step of nucleation only empirically. Such models assume that the particules begin to nucleate with a fixed size, once the saturation exceeds a critical value. Moreover, their growth or re-dissolution rate is usually assumed independent of their size, which does not allow describing some effects such as Ostwald ripening. A new model was proposed by Noguera and al. (2006) to correct this weakness. It is controlled by a system of highly non-linear integro-differentials equations which combines the effects of : homogeneous or heterogeneous nucleation, growth and ripening of particles or their re-dissolution as a function of the evolution of the saturation of the concerned mineral phases in the aqueous solution. Due to the nucleation, the number of particles is numerically a function of time strictly increasing. Moreover, to predict the evolution of the system, it is necessary to know the status of each particle at any moment and to remember the history of its evolution. This is very costly in terms of data storage and data processing. The aim of this thesis was to develop an algorithm of numerical resolution that can perform a fast and accurate calculation in order to introduce it in the fluid-rock interactions simulation model, taking into account the germination and growth of pure mineral phases or phases whose composition may vary during their formation, like sollids solutions. The resulting software is called "Nanokin". This approach allows following the size evolution of each particle, as a function of time. It also describes the contribution of each particle to the entire population of particles (number of particles, number of moles)
Davenport, Jesse. "Isotopic tracing of silicate and carbonate weathering in the Himalayan erosional system." Electronic Thesis or Diss., Université de Lorraine, 2018. http://www.theses.fr/2018LORR0241.
Full textWeathering of Himalayan lithologies has had a potential impact on the global carbon cycle. To be able to constrain and understand the processes that occurred in the Himalayas that affected these cycles, we must be able to distinguish the signatures of silicate and carbonate weathering in the dissolved load of Himalayan rivers. Previous studies have attempted to do this using a variety of methods but there is still not a clear consensus on the magnitude and flux of silicate weathering in the Himalaya. This thesis proposes the use of 40Ca as a tracer that could improve the quantification of the silicate and carbonate weathering flux in the dissolved load of Himalayan rivers. Previous work has shown that the 40Ca budget of seawater is dominated by a mantle source, such that marine carbonates have a homogeneous 40Ca signature indistinguishable from the mantle value. In contrast, the upper silicate crust is expected to have developed a radiogenic composition. The difference between the radiogenic Ca signature of carbonate and silicate lithologies can be therefore used to differentiate between carbonate and silicate weathering in the dissolved load of rivers. Here, we present a geochemical survey, including radiogenic Ca analyses, of rivers draining the main lithological units of the Himalaya, as well as results from sediments, bedrock, soil and gravel. Our results show that Himalayan carbonates exhibit no radiogenic 40Ca excesses despite highly variable 87Sr/86Sr signatures, whereas sediments are variably radiogenic (+0.9 to +4). This suggests that for Ca, unlike for Sr, isotopic exchange between the silicate and carbonate lithologies has been minimal. The radiogenic Ca composition of river water ranges from +0.1 in carbonate dominated catchments to +11 in rivers draining silicate catchments. For large rivers, silicate and carbonate weathering budget estimates based on major elements and radiogenic Ca compositions tend to agree. However, for some smaller rivers, especially those draining silicate dominated basins in the HHC and LH formations, some discrepancies are observed. These cannot be attributed to poor definition of the chemical or radiogenic Ca composition of the endmembers used for budget modeling, as the values required to bring the estimates into agreement are unreasonable. They also cannot be explained by precipitation of secondary carbonates in the rivers as the non-radiogenic composition of the carbonate fraction of sediments suggests that this process is only minor. Rather, these discrepancies may be due to the dissolution/weathering of trace amounts of radiogenic calcite contained within HHC and LH silicate lithologies. The weathering of such material, which represents only a tiny fraction of the area of the silicate catchment, could yield a substantial proportion of the radiogenic Ca and may thus have a significant influence on the isotopically based weathering budgets of these basins. Nevertheless, as this effect is observed primarily in basins with low silicate erosion rates, its influence on estimates of the overall silicate weathering flux will be minor. More generally, the results of this thesis imply that the 40K–40Ca system can resolve issues that cannot be successfully addressed using Sr isotopes in the Himalaya. Further work is needed to define the full range of radiogenic Ca compositions in the Himalaya in order to clearly answer questions regarding silicate weathering fluxes
Nourtier-Mazauric, Elise. "Modélisation géochimique et numérique des interactions entre des solutions solides et une solution aqueuse. Extension du logiciel de réaction-transport Archimède et application à la diagénèse minérale des réservoirs." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2003. http://tel.archives-ouvertes.fr/tel-00088991.
Full textCe modèle a été intégré au logiciel de transport réactif en milieu poreux ARCHIMEDE, puis appliqué à divers exemples. Dans le cas de solutions solides binaires, une méthode graphique a permis de déterminer les compositions des solutions solides qui précipitent, à l'aide des potentiels chimiques des pôles.
Le logiciel ainsi obtenu pourrait être utilisé pour modéliser notamment la diagenèse des réservoirs pétroliers argileux ou carbonatés, ou la dispersion de polluants dans le sol.
Gal, Frédérick. "Etude géochimique et isotopique des eaux de surface du bassin versant du Furan et des eaux minérales du graben du Forez, Est du Massif Central français." Saint-Etienne, 2005. http://www.theses.fr/2005STET4018.
Full textThe Eastern French Massif Central (hercynian basement and Oligocene Forez graben), is the aim of a geochemical study of rain-, surface-, and mineral waters. Stable isotopes study (18O, 2H) of rainfalls allows to build a local meteoric water line, to quantify altitudinal gradients, and to determine water transit times within the surface aquifers. Total Dissolved Solids of the rivers and surface aquifers range from 30 to 500 mg/l. Saturation index show little interaction with the granite matrix. D13C ratios indicate a strong proportion of dissolved organic matter. D180 and dD indicate a major refill during winter times. Modelling underground transit times give estimations of about 8 to 15 month (oxygen and hydrogen isotopes). Seven mineral springs (6 carbogaseous, 2 of thermal bearing) belong to 3 chemical facies : Ca-Mg-HCO3, Na-HCO3-C1 and Na-HCO3. Saturation index indicate a clear interaction within the basement (precipitation/dissolution). Quantification of deep temperatures by cation geothermometry give a wide range from 150 to 240°C. Altitudes of recharge areas are close to those of the current reliefs. D13C ratios are strongly influenced by the signature of deep CO2 ; a thermal spring (Na-C1-HCO3) has different values (interaction with sedimentary formations). Some Ca-Mg-HCO3 waters are mixtures with surface water (3H). Maximum times of transit (14C) range from 20000 to 25000 years, and 8000 years for the above mentioned thermal spring
Gal, Frédérick. "ETUDE GEOCHIMIQUE ET ISOTOPIQUE DES EAUX SUPERFICIELLES DU BASSIN VERSANT DU FURAN ET DES EAUX MINERALES DU GRABEN DU FOREZ, EST DU MASSIF CENTRAL FRANÇAIS." Phd thesis, Université Jean Monnet - Saint-Etienne, 2005. http://tel.archives-ouvertes.fr/tel-00011941.
Full textLa première partie repose sur l'étude en isotopes stables (18O, 2H) des précipitations locales (3 points de mesures ; prélèvements journaliers sur 1 à 3 ans), dont les contenus en tritium permettent de déterminer le bruit de fond atmosphérique actuel. Les mesures 18O, 2H ont permis de construire une droite locale des eaux météoriques et de quantifier les gradients d'appauvrissement des rapports isotopiques en fonction de l'altitude. Ceci permet aussi de déterminer les temps de transit de l'eau dans les aquifères superficiels et de détecter la présence d'eaux récentes dans des eaux plus minéralisées. De plus, une évaluation des quantités d'eau réellement disponibles à l'infiltration (et de leur signature isotopique) a été entreprise en se basant sur différentes méthodes de calcul de l'évapotranspiration.
La seconde partie consiste en l'étude de rivières et d'aquifères peu profonds, majoritairement situés en zone d'arène granitique et connaissant des variations de débit marquées. La détermination des contenus en éléments majeurs cations et anions donne des gammes de Solides Totaux Dissous variant de 30 à 500 mg/l pour les sources, de pH acide à neutre et de faciès Na-Ca-Cl-HCO3. Les calculs d'indice de saturation, incluant les phases minérales des sols locaux, montrent une interaction limitée avec les produits d'altération d'une matrice rocheuse granitique. Les rapports isotopiques en carbone 13 indiquent une forte proportion de matière organique dissoute. La détermination des d18O et dD permet d'envisager une recharge préférentielle en hiver ainsi que des gradients d'altitude proches de ceux enregistrés par les pluies. L'utilisation de modèles de transit souterrain de type « dispersion » permet d'estimer des temps de transit moyens de 10 à 15 mois en oxygène et 8 à 13 mois en hydrogène.
Enfin, 7 sources minérales, en contexte granitique faillé ou sédimentaire, ont également fait l'objet de prélèvements réguliers. Six d'entre elles sont carbogazeuses, deux ont un caractère thermal. Trois faciès chimiques, marquant une augmentation de la minéralisation, sont représentés : Ca-Mg-HCO3, Na-HCO3-Cl et Na-HCO3. Les indices de saturation indiquent une nouvelle fois une nette interaction avec le socle. Or, les précipitations/dissolutions d'espèces minérales modifient les concentrations en cations. Dès lors, les estimations de température profonde des réservoirs (géothermomètres à cations) donnent une gamme de variation de 150 à 240°C. Les rapports isotopiques en oxygène et hydrogène sont beaucoup plus stables que ceux des eaux de surface, les eaux Na-HCO3 ayant des deltas appauvris par rapport à leurs altitudes d'émergence. La détermination des altitudes des aires de recharge, en utilisant les gradients déterminés sur les pluies, donne des altitudes compatibles avec celles des reliefs locaux. Les signatures en carbone 13 sont influencées par la signature du CO2 profond pour les sources carbogazeuses. Une source thermale (faciès Na-Cl-HCO3) a des valeurs très différentes. Certaines sources du faciès Ca-Mg-HCO3, par leur contenu en tritium, attestent de mélanges avec des eaux de surface, de faible importance cependant (13C, 14C). Pour l'ensemble des sources minérales, les durées maximales de temps de transit obtenues par le carbone 14 sont de l'ordre de 20000 à 25000 ans, alors que cette durée est de 8000 ans pour la source thermale précédemment mentionnée.
Walter, Anne-Véronique. "Caractérisation géochimique et minéralogique de l'altération de la carbonatite du complèxe alcalin de Juquia (Brésil), comportement des terres rares dans les minéraux phosphatés." Aix-Marseille 3, 1991. http://www.theses.fr/1991AIX30008.
Full textParseval, Philippe de. "Etude minéralogique et géochimique du gisement de talc et chlorite de Trimouns (Pyrénées, France)." Toulouse 3, 1992. http://www.theses.fr/1992TOU30184.
Full textGama, Sophie. "Evénements métallogéniques à W-Bi (Au) à 305 Ma en Châtaigneraie du Cantal : apport d'une analyse multi-spectrométrique (micro PIXE-PIGE et Raman) des minéraux et des fluides occlus à l'identification des sources de fluides hydrothermaux." Phd thesis, Université d'Orléans, 2000. http://tel.archives-ouvertes.fr/tel-00002404.
Full textL'emploi d'un "funny filter" lors de l'analyse PIXE permet la détection des éléments K à U. Ce travail illustre que cette méthode est absolue à condition que la géométrie du dispositif analytique soit connue précisément. La paragenèse primaire à W possède une signature d'éléments traces d'affinité leucogranitique (F, Mn, Zn, Ga, As, Nb, Sn, Ta, W, Bi). L'arsenic apparaît écouplé des leucogranites et contrôlé par les micaschistes encaissants : cet élément est détecté dans les fluides du métamorphisme barrovien (¡Ö340 Ma) et les minéraux et fluides du stade à W (¡Ö305 Ma). Les caisses filoniennes subissent une fracturation en tension, une intense dissolution du quartz, un dépôt géodique
de pyrite et muscovite, une paragenèse à bismuth natif, bismuthinite, molybdénite, chalcopyrite, covellite, tennantite, waylandite, cannonite, sidérite et chlorite. Des tourmalinites massives stériles se développent, en veines ou en remplacement, de façon contemporaine. Les tourmalinites de La Granière présentent du quartz cataclastique avec de nombreuses microinclusions de biotite, muscovite, feldspath potassique, ilménite, zircon, monazite et xénotime. Le cortège de traces de ce stade est caractérisé par Fe, Mn, Cu, Zn, Ti, Cr, Sc, V, Se, Zr, Ag, Cd, Ba, Sr, Sb, Hf, Y, La, Ce et Th.
Les fluides associés sont aquo-carboniques, riches en K, Ca, métaux de base. Le caractère de ce fluide, alumino-potassique, sous-saturé en silice, phosphaté, chargé en métaux lourds et de transition (y compris Cr et Sc), REE, LILE et HFSE, suggère une affinité avec des fluides métasomatiques du manteau, ce que confirment la géochimie, la minéralogie et la texture d'un lamprophyre sécant sur une veine minéralisée. La chimie des minéraux et des fluides indique une ébullition généralisée des
solutions à ce stade en liaison avec le flux thermique élevé et la remontée rapide du bâti en fin d'orogenèse.
Tarantola, Alexandre. "Les mécanismes rédox contrôlant la chimie du carbone dans les fluides de l'anchi-métamorphisme : composition des paléofluides, géochimie isotopique, cristallochimie des minéraux phylliteux dans la partie externe des alpes centrales (Suisse)." Nancy 1, 2005. http://www.theses.fr/2005NAN10163.
Full textThis works characterizes the mechanisms at which occurs the transition between CH4- and H2O- dominated fluid zone in the anchi-metamorphic rocks of the External part of Central Alps, Switzerland. Fluid inclusion trapped in fibre quartz during crack-and-seal mechanism record increasing metamorphic conditions during Alpine orogene. The end of the CH4-zone is characterized by a marked increase of CO2 at 270 ± 5°C. The decrease of CH4 and CO2 in the H2O-zone is contemporaneous with presence of calcite, totally filling Alpine fissures. Isotopic fractionation (delta13C) between methane and calcite is in agreement with homogenisation temperatures of fluid inclusion. DeltaD(H2O) and delta13C(CO2) values of fluid inclusions at the end of the CH4-zone characterise methane oxidation. In agreement with Mössbauer spectroscopy and EELS analyses, neoformation of chlorite and muscovite from detrital biotite is considered as the Fe-reduction driving force of the oxidation of fluid
Negra, Lotfi. "Pétrologie, minéralogie et géochimie des minéralisations et des roches encaissantes des bassins associés aux structures tectoniques et magmatiques de l'Oued Belif et du Jebel Haddada (Nord des Nefza, Tunisie septentrionale)." Paris 11, 1987. http://www.theses.fr/1987PA112253.
Full textBardot, Frédérique. "Les minéraux argileux et leur hétérogénéité superficielle : influence de la nature des cations compensateurs superficiels de l'illite sur les mécanismes d'adsorption de gaz." Vandoeuvre-les-Nancy, INPL, 1998. http://docnum.univ-lorraine.fr/public/INPL_T_1998_BARDOT_F.pdf.
Full textNgombi-Pemba, Lauriss-Paule. "Géochimie et minéralogie des formations argileuses (2.2 - 2.0 Ga) du bassin de Franceville au Gabon : fluctuations de l'oxygène atmosphérique, chimie des océans et diagenèse au Paléoprotérozoïque." Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2259.
Full textThe Paleoproterozoic Francevillian series (2.2–2.0 Ga) of Gabon is well known for its natural nuclear reactor and for having provided evidence of the earliest large colonial macrofossils. These ancient rocks also contain unexpected smectite-rich mixed layers minerals. However, few data are available yet on the oxygenation state of the atmosphere and ocans during the deposition of the Francevillian sediments. In order to investigate the nature of marine water-column chemistry, samples representing the entire section (FB, FC, and FD formations) were subjected to multielement (C, S, Fe, trace metals, and REE) biogeochemical study. In addition, to assess the impact of atmospheric and oceanic paleoredox conditions on clay minerals, a clay minralogical study was performed. Geochemical data show deep water oxic conditions during deposition of FB and FC formations in agreement with the Lomagundi Event (LE). Nevertheless the interlayered Mn and Fe deposits occured in ferruginous anoxic conditions reflecting sea-level changes. The FD black shales reflect euxinic conditions. These conditions, are indicated by trace metals enrichment, negative shift of δ13Corg values and δ98Mo. The Francevillian series show direct geochemical evidence for the state of atmospheric and ocean oxygenation both during and after the LE. These data confirm a significant decrease in the oxygenation of ocean water in the aftermath of the LE and the Great Oxidation Event (GOE). The mineralogical results reveal that the clay mineralogical signature observed in the basin, is not the consequence of the atmospheric oxygen fluctuations. The survival of smectitic minerals is strictly dependent on diagenetic transfo
Kausar, Allah Bakhsh. "L'arc sud Kohistan, N. Pakistan : évolution pétrologique et distribution des éléments et minéraux du groupe du platine." Phd thesis, Université Joseph Fourier (Grenoble), 1998. http://tel.archives-ouvertes.fr/tel-00717476.
Full textDavenport, Jesse. "Isotopic tracing of silicate and carbonate weathering in the Himalayan erosional system." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0241.
Full textWeathering of Himalayan lithologies has had a potential impact on the global carbon cycle. To be able to constrain and understand the processes that occurred in the Himalayas that affected these cycles, we must be able to distinguish the signatures of silicate and carbonate weathering in the dissolved load of Himalayan rivers. Previous studies have attempted to do this using a variety of methods but there is still not a clear consensus on the magnitude and flux of silicate weathering in the Himalaya. This thesis proposes the use of 40Ca as a tracer that could improve the quantification of the silicate and carbonate weathering flux in the dissolved load of Himalayan rivers. Previous work has shown that the 40Ca budget of seawater is dominated by a mantle source, such that marine carbonates have a homogeneous 40Ca signature indistinguishable from the mantle value. In contrast, the upper silicate crust is expected to have developed a radiogenic composition. The difference between the radiogenic Ca signature of carbonate and silicate lithologies can be therefore used to differentiate between carbonate and silicate weathering in the dissolved load of rivers. Here, we present a geochemical survey, including radiogenic Ca analyses, of rivers draining the main lithological units of the Himalaya, as well as results from sediments, bedrock, soil and gravel. Our results show that Himalayan carbonates exhibit no radiogenic 40Ca excesses despite highly variable 87Sr/86Sr signatures, whereas sediments are variably radiogenic (+0.9 to +4). This suggests that for Ca, unlike for Sr, isotopic exchange between the silicate and carbonate lithologies has been minimal. The radiogenic Ca composition of river water ranges from +0.1 in carbonate dominated catchments to +11 in rivers draining silicate catchments. For large rivers, silicate and carbonate weathering budget estimates based on major elements and radiogenic Ca compositions tend to agree. However, for some smaller rivers, especially those draining silicate dominated basins in the HHC and LH formations, some discrepancies are observed. These cannot be attributed to poor definition of the chemical or radiogenic Ca composition of the endmembers used for budget modeling, as the values required to bring the estimates into agreement are unreasonable. They also cannot be explained by precipitation of secondary carbonates in the rivers as the non-radiogenic composition of the carbonate fraction of sediments suggests that this process is only minor. Rather, these discrepancies may be due to the dissolution/weathering of trace amounts of radiogenic calcite contained within HHC and LH silicate lithologies. The weathering of such material, which represents only a tiny fraction of the area of the silicate catchment, could yield a substantial proportion of the radiogenic Ca and may thus have a significant influence on the isotopically based weathering budgets of these basins. Nevertheless, as this effect is observed primarily in basins with low silicate erosion rates, its influence on estimates of the overall silicate weathering flux will be minor. More generally, the results of this thesis imply that the 40K–40Ca system can resolve issues that cannot be successfully addressed using Sr isotopes in the Himalaya. Further work is needed to define the full range of radiogenic Ca compositions in the Himalaya in order to clearly answer questions regarding silicate weathering fluxes
Parrello, Damien. "Conception de biosenseurs fluorescents multicolores pour l'identification in vivo des interactions bio-physicochimiques dans les systèmes minéral-bactérie." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0362/document.
Full textMonitoring terrestrial ecosystems requires a better understanding of the interactions between microorganisms, minerals and metals in the environment. To assess in vivo availability of metals such as iron in bacteria-mineral system, an approach based on whole-cell fluorescent biosensors and non-invasive spectroscopy was explored. This work led to the construction in Pseudomonas aeruginosa of a set of gene fusions coupling iron-regulated promoters to multicolour fluorescent reporters. The recombinant strains were used as sensors of structural iron availability in nontronites NAu-1 and NAu-2. The response of these biosensors was studied by coupling synchronous fluorescence spectroscopy (SFS) with canonical polyadic Candecomp/Parafac (CP) decomposition. On the basis of experimental designs favouring response diversity, the coupled SFS-CP method guarantees a joint estimate of gene expression from multiple promoters, even in highly fluorescent media. This novel method can solve the issue of spectral bleed-through of fluorescent proteins and provides a means to integrate multiple signals from combinations of whole-cell fluorescent bioreporters. In addition, we could show using SFS-CP that P. aeruginosa indirectly mobilize Fe(III) from nontronites primarily through the production of pyoverdine siderophore. The structural Fe(III) present on the edges of NAu-2 rather than NAu-1 particles appears to be more bioaccessible, suggesting that the distribution of Fe, in the tetrahedron and/or in the octahedron sites, governs the solubilization process
Lepleux, Cendrella. "Altération bactérienne des minéraux dans les écosystèmes forestiers pauvres en nutriments : Analyse des communautés bactériennes et identification des mécanismes impliqués." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0184/document.
Full textIn nutrient-poor forest ecosystems, minerals are the main source of inorganic nutrients for the long lasting functioning of the forests. However, these nutrients are not directly accessible to the tree roots. It is the joined action of abiotic factors, such as pH and water circulation, and biotic factors such as tree roots and soil microorganisms, and notably bacteria, which leads to the solubilisation of these minerals. To date, our knowledge of the bacterial communities involved in the mineral weathering process and their distribution in forest soils is very limited and remains restricted to habitats such as the rhizosphere and mycorrhizosphere. The goals of this PhD thesis were to characterise the mineral associated bacterial communities, their ability to weather minerals and finally to identify the bacterial genes involved in the mineral weathering process. The combination of geochemical, cultivation-dependent and -independent approaches applied on minerals grounded in a forest soil during 4 years, revealed that the mineral associated bacterial communities were specific, able to weather minerals and had restricted metabolic abilities. These results suggest that minerals could be considered as a true ecological habitat: the mineralosphere. The mineral/bacteria relationship was tested in situ through a mineral amendment applied on a small-scale plantation, which has highlighted that the nutrient availability impacted the functional structure of the mineral weathering bacterial communities. At least, random mutagenesis applied on a model mineral weathering bacterial strain revealed that its mineral weathering ability resulted from several molecular mechanisms
Lach, Philippe. "Signature géochimique des éléments des terres rares dans les oxydes d'uranium et minéraux associés dans les gisements d'uranium : analyse par ablation laser couplée à l'ICP-MS et étude géochronologique." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0259/document.
Full textThe ore deposits often display complex stages of formation leading to multiphase mineral crystallizations. The study of these minerals needs to use a sensitive and localized analytical method. Laser ablation coupled to ICP-MS is a good tool for in-situ measurements of low element concentrations (<10 ppm) at a small scale in minerals (around 10 ?m diameter). Two major objectives concerning the use of LAICP-MS have been carried out in this thesis. First part is focused on the determination of the best analytical conditions for rare earth element (REE) quantification with LA-ICP-MS in uranium oxides and associated minerals (carbonate, fluorite). This approach has been coupled to isotopic analysis using ionic microprobe. The second part is dedicated to the application of the methodology on 21 uranium ore bodies typical of four different types of deposits. The uranium oxides from unconformity-related uranium deposits (Athabasca Basin) show typical REE signature whatever their age and location. Data on End Grid U mineralization (Thelon basin) suggest similar conditions of formation and ages as in Athbasca unconformity related uranium deposits. High temperature during magmatic uraninite formation induced strong incorporation of REE in their structures. REE signatures of uranium oxides related to vein type deposits suggest a control of the host rocks. Finally, the different REE signatures obtained on uranium oxides from breccia pipe-related deposit show a strong variation in the conditions of formation in these supposed similar deposits
Merrot, Pauline. "Géochimie, spéciation et mobilité des éléments traces métalliques (Fe, Ni, Cr et Mn) au sein des sédiments du lagon de Nouvelle-Calédonie." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS551.pdf.
Full textNew Caledonia is covered on 33% of ultramafic rocks enriched in trace metals elements (Fe, Ni, Cr, Mn and Co). The erosion of these massifs represents an important source of these trace metals towards the lagoon, partially registered on the World List Heritage by UNESCO for its biodiversity. Understanding the geochemical cycle of these toxic trace metals is essential to evaluate the potential impacts on the biodiversity of this ecosystem. X-ray absorption spectroscopy (XAS) has shown that the contribution of iron sulfides is low, Ni and Fe are bearing by goethite and clays. These latter minerals representing the major phase for the Fe and Ni speciation were identified as chrysotile and green clays: a smectite (nontronite), a mica (glauconite) and a serpentine like a greenalite/berthierine. The clay minerals cycle and the green clay plays a major role in the Fe and Ni cycle, but also in Mn and to a lesser extent in the Cr cycles. The Mn speciation is shared by the clay minerals and the carbonates species whereas Cr is bearing by goethite and chromite inherited of laterite and in lesser extent by clay minerals. Cr is totally present under the reduced form which is the less toxic form. This absence of Cr(VI) is linked to the absence of Mn oxides in sediments avoiding the oxidation of Cr(III) to Cr(VI) and thus limits the impact on the environment. Finally, the chemical extractions of these metals show a relatively low bioavailability of trace metals except for Mn implying an effective long-term trapping for trace metals and thus limiting the environmental impacts even if the concentrations extracted are not negligible and can be threaten the biodiversity of the lagoon
Mathieu, Régis. "Reconstitution des paléocirculations fluides et des migrations élémentaires dans l'environnement es réacteurs nucléaires naturels d'Oklo (Gabon) et des argilités de Tournemire (France)." Vandoeuvre-lès-Nancy, INPL, 1999. http://www.theses.fr/1999INPL072N.
Full textTo better characterize the mobilization and migration process in rocks, a petrological and geochemical study of fluid paleocirculation through fractures has been made in two different sites : 1) The environment of natural nuclear reactors from Proterozoic Oklo uranium ores (Gabon). 2) The Toarcian shales from experimental IPSN site in the Tournemire, tunnel (Aveyron, France)