Depuis de nombreuses années, une approche a été mise en œuvre reposant sur l'identification de l'origine géographique d'un produit agro-alimentaire via la connaissance de ses isotopes du Sr, notamment via l'analyse du rapport 87Sr/86Sr. L'objectif de cette thèse est d'appliquer cette stratégie de reconnaissance aux huiles d'olive, en s'appuyant sur la production des huiles AOP de Nîmes dans le Sud de la France (Gard). La viscosité, la charge organique élevée, la teneur faible en Sr de cette matrice, rendent néanmoins inadaptés les protocoles de purification du Sr existants. La première approche de l'étude correspond donc à la définition et à la validation d'une méthode de traitement des huiles d'olive en vue de la purification du Sr afin de procéder à l'analyse de sa composition isotopique (CI). La seconde partie de l'étude est consacrée à la définition des processus d'assimilation et de transfert du Sr dans l'olivier. Cette approche, menée grâce à une étude détaillée d'un des moulins AOP de Nîmes, a permis de démontrer que le transfert du Sr des sols vers l'olivier et au sein des oliviers se fait sans fractionnement isotopique.La dernière partie de l'étude s'appuie sur la mesure et la caractérisation des rapports isotopiques 87Sr/86Sr des dix huiles d'olive AOP de Nîmes, et une comparaison de cette signature avec celle des formations géologiques sur lesquelles reposent les parcelles de culture. L'identité de la CI huile-territoire de culture a permis de conclure, dans le contexte de production de l'huile d'olive AOP de Nîmes, que les isotopes du Sr constituent un très bon outil de traçage de l'origine géographique des produits oléicoles. / For many years, an approach based on the identification of the geographical origin for food product has been implemented through the knowledge of its Sr isotopes, particularly through the analysis of 87Sr / 86Sr ratio. The objective of this thesis is to develop a similar strategy for the olive oils, from the example of PDO Nimes (Gard), in southern France. A specific methodology is necessary since the existing purification protocols of Sr revealed themselves inadequate because of viscosity, high organic load, low Sr content of this matrix In order to proceed to the analysis of the isotopic composition (IC), the first part of the study highlights the definition and validation of a specific method for the treatment of olive oils and strontium purification. The second part of the study is dedicated to expose the processes of assimilation and transfer of strontium into the olive tree. This approach, conducted through a detailed study of one of Nîmes PDO mills, demonstrated that the transfer of strontium from soils to olive tree, and within the olive tree, occurs without isotope fractionation.The last part of the manuscript studies the isotopic ratios 87Sr / 86Sr of the ten PDO olive oils of Nimes and consists in a comparison of this signature with the geological formations underlying the cultivation soils. This approach allows discussing quality of Sr isotopic tool in the geographical recognition of the olive products. The observed similarity between th IC from oils and soil allow us to conclude that, in this context of production, the Sr isotopes are a efficient tool to trace and certify the geographical origin of the oil.

Les spéléothèmes (concrétions carbonatées se formant dans les zones karstiques) sont des archives paleo-climatiques reconnues, dont l’intérêt majeur est de pouvoir être datées précisément par la méthode Uranium-Thorium. En revanche, les traceurs traditionnellement utilisés pour reconstruire les climats passés à partir de ces objets géologiques ne sont pas directement quantifiables en termes de paramètres climatiques comme la température moyenne, ou la quantité de précipitation. Les variations des concentrations en éléments traces contenus dans les spéléothèmes ont pu être relié dans certains sites aux changements climatiques passés, mais des doutes existent sur la robustesse de leur signal au sein d’une même grotte et entre différents sites.Nous nous sommes appliqués à déterminer les variations au cours des 50 000 dernières années de plusieurs catégories d’éléments (alcalino-terreux, uranium, et terres rares) dans des stalagmites de deux grottes situées dans le sud de la France (les grottes de Villars en Dordogne et de Chauvet en Ardèche), par spectrométrie ICP-MS. Les spéléothèmes sélectionnés ont déjà été datés et ont enregistré les variations paleo-environnementales à travers les isotopes stables de la calcite. Trois périodes d’étude caractérisées par des changements particuliers sont étudiées: le stade isotopique 3 de la dernière période glaciaire (~50-30 ka), la dernière déglaciation (~20-10 ka) et la fin de l’Holocène (~2-0 ka).Le signal des variations des alcalino-terreux à Villars pendant le stade isotopique 3 est significatif et robuste. La variabilité du strontium notamment, qui provient de processus hydrologiques intra-karst, suit les événements climatiques rapides enregistrés dans l’hémisphère Nord. D’autre part, le comportement de nombreux éléments traces pendant la déglaciation est similaire entre les grottes de Villars et de Chauvet. Enfin, des changements du couvert végétal sont probablement à l’origine des changements synchrones enregistrés par les éléments traces et les isotopes stables de la calcite au cours des deux derniers millénaires à Villars.Par ailleurs, l’étude des coefficients de partition des alcalino-terreux, de l’uranium et des terres rares dans des conditions variées montre l’importante de la variabilité inter-site de leur partitionnement. / Calcareous deposits forming within caves, also known as speleothems, have become acknowledged paleoclimatic archives. One of their main interests is that they can be absolutely dated by Uranium-Thorium methods. However, traditionally used speleothem climatic proxies cannot be directly translated into environmental variables such as the mean annual temperature or the amount of annual rainfall. In some contexts, the variations of trace element concentrations in speleothem calcite could be linked to past climatic changes, but the robustness of trace element signals between speleothems of the same or nearby caves is still questionable.We determined by ICP-MS the concentrations of several families of chemical elements (alkaline-earth metals, uranium, rare-earth elements) in stalagmites from two caves located in Southern France (Villars cave in Dordogne and Chauvet Cave in Ardèche) spanning the last 50,000 years. The selected speleothems had already been dated and their stable isotope profiles had proven to record paleoenvironmental fluctuations occurring during three separate periods: the Marine Isotopic Stage 3 or MIS 3 (~50-30 ka), the Last Deglaciation (~20-10 ka), and the end of the Holocene (~2-0 ka).Variations of alkaline-earth metals recorded in two stalagmites from Villars Cave during MIS 3 are significant and robust. Notably, Sr concentrations follow the rapid climatic changes recorded in the Northern Hemisphere. Furthermore, several trace elements behave similarly during the Last Deglaciation in the Villars and the Chauvet Cave. Finally, changes of the vegetation cover above the cave are likely to have caused the synchronous fluctuations of the trace element and stable isotope contents that happened during the last two thousand years in Villars speleothems.Lastly, the partition coefficients of alkaline-earth metals, uranium and rare-earth elements were measured in different sites and conditions and proved to be very site-dependent.

Stream chemistry changes in response to snowmelt, but does not typically reflect thechemistry of the snowpack. This suggests that flow processes between snowmelt and streamsystem, such as interactions with the soil and bedrock, have an important control on waterchemistry and highlight the complex flow pathways from the snowpack to stream. To investigateflow processes in the upper Provo River watershed, northern Utah, we sampled three sites on theriver ~20 times per year during 2016 and 2017. The sites, from highest elevations to lowest wereSoapstone, Woodland, and Hailstone, corresponding to locations of active stream gauges. Toidentify possible water sources to the stream during snowmelt, water samples were taken forsnow, ephemeral streams, soil water, lake, and spring water. To investigate potential impacts ofmineralogy, samples were taken for dust, soil and bedrock. The upper Provo River showeddistinct temporal variation in filtered (<0.45 microns) stream water for 87Sr/86Sr, dissolvedorganic carbon (DOC), silica (Si), and Lead (Pb) during the snowmelt season. The watershed hasdistinct 87Sr/86Sr ratios for bedrock (0.7449)

O Escudo Sul-Rio-Grandense, importante elemento da geologia do sul do Brasil, possui, em seus diferentes domínios geotectônicos, ocorrências de mármores que foram relativamente pouco estudadas. Sabendo da importância dessas rochas para um maior entendimento da estratigrafia, do contexto de formação e evolução regional, foram escolhidas quatro pedreiras em dois domínios geotectônicos distintos: Fida, Mudador e Inducal na região de Caçapava do Sul (RS) – Terreno São Gabriel – e Matarazzo na região de Arroio Grande (RS) – Batólito Pelotas. A metodologia empregada no trabalho incluiu análises de petrografia, geoquímica e isótopos de Sr, aplicadas em 38 amostras dentre as 91 coletadas nas quatro áreas de estudo. A classificação das rochas através dos resultados da análise petrográfica foi aprimorada com os dados geoquímicos, especialmente quanto aos teores de MgO, SiO2 e CaO e sua distribuição. Nos mármores de Caçapava do Sul, há predomínio de dolomita, corroborado pelo teor de MgO (17,66 a 21,52%) e classificados como dolomíticos. Na região de Arroio Grande, domina calcita, com concentrações de MgO entre 0,44 e 0,54% e os mármores são classificados como calcíticos. Os teores de CaO ficaram entre 26,24 e 31,59% nos mármores de Caçapava do Sul e entre 51,37 e 53,24% no mármore de Arroio Grande, complementando a afirmação anterior. Essa diferença foi percebida também nos resultados dos ETRs, tanto na avaliação do comportamento geral destes elementos, quanto na avaliação de anomalias individuais (Ce e Eu), que indicaram componente marinho nos mármores Matarazzo e presença de processos envolvendo contribuição de fluidos hidrotermais nas rochas Fida e Inducal. Essa contribuição de fluidos posteriores e não originais foi observada, também, com a avaliação das razões Mn/Sr, Sr/Ca e os teores de MnO e Sr. As razões 87Sr/86Sr variam entre 0,704 e 0,713 para os mármores Fida; 0,709 e 0,714 para Mudador; 0,705 e 0,709 para Inducal e 0,7060 e 0,7067 para Matarazzo. O mármore Matarazzo é o que possui os valores mais próximos da composição original, sendo o que possui o resultado original mais confiável; o mármore Inducal apresenta resultados que demonstram composição original questionável, mas ainda dentro do campo aceitável pela literatura; e as rochas Fida e Mudador não apresentaram condições confiáveis nesse sentido. Os resultados interpretados sugerem que a formação dos mármores de Arroio Grande ocorreu entre 900 e 850 Ma e Caçapava do Sul entre 800 e 750 Ma, em ambientes deposicionais distintos. / The Sul-Rio-Grandense Shield is an important element of southern Brazil geology. It includes few known marble occurrences in its geotectonic domains. In order to understand better the local stratigraphy, geological setting and regional evolution, four quarries were selected in two distinct geotectonic domains: Fida, Mudador and Inducal quarries located at around Caçapava do Sul (RS) city– São Gabriel Terrain –; Matarazzo quarry at around Arroio Grande (RS) region – Pelotas Batholith. Methodology includes petrography, geochemistry and Sr isotopes analysis, applied in 38 samples from 91 collected in four studied areas. Rocks classification through the results of petrographic analysis was enhanced by geochemistry data, especially when it comes to MgO, SiO2 and CaO contents and their distribution. Caçapava do Sul marbles show dolomite predominance, since this data is corroborated by the MgO content (17.66 to 21.52%) and it is classified as dolomitic. At the Arroio Grande region, calcite prevails, and the MgO content ranges between 0.44 and 0.54% and the marbles are classified as calcitic. Caçapava do Sul marbles include CaO contents ranging between 26.24 and 31.59% whereas Arroio Grande marble ranges between 51.37 and 53.24%, complementing the previous statement. This difference was also observed in the REE’s results, as much in evaluation of the general behavior of these elements as in evaluation of individual anomalies (Ce and Eu), which indicate a marine component on Matarazzo marbles and the presence of processes involving contribution of hydrothermal fluids on Fida and Inducal rocks. This contribution of posterior fluids and non original fluids was also observed with the evaluation of Mn/Sr, Sr/Ca ratios and MnO and Sr contents. The 87Sr/86Sr ratios range from 0.704 to 0.713 on the Fida marbles; 0.709 to 0.714 on Mudador; 0.705 to 0.790 on Inducal and from 0.7060 to 0.7067 on Matarazzo. Matarazzo marble is the only rock that has the closest values compared to the original composition, and it is only one that has the most reliable original result; Inducal marble shows results that demonstrate dubious values when compared to original composition, but still within the acceptable field according to the literature; Fida and Mudador rocks do not present reliable conditions in this regard. Interpreted results suggest that Arroio Grande marbles were generated between 900 and 850 Ma whereas Caçapava do Sul marbles between 800 and 750 Ma. Both of them were developed under different depositional environments.

O Escudo Sul-Rio-Grandense, importante elemento da geologia do sul do Brasil, possui, em seus diferentes domínios geotectônicos, ocorrências de mármores que foram relativamente pouco estudadas. Sabendo da importância dessas rochas para um maior entendimento da estratigrafia, do contexto de formação e evolução regional, foram escolhidas quatro pedreiras em dois domínios geotectônicos distintos: Fida, Mudador e Inducal na região de Caçapava do Sul (RS) – Terreno São Gabriel – e Matarazzo na região de Arroio Grande (RS) – Batólito Pelotas. A metodologia empregada no trabalho incluiu análises de petrografia, geoquímica e isótopos de Sr, aplicadas em 38 amostras dentre as 91 coletadas nas quatro áreas de estudo. A classificação das rochas através dos resultados da análise petrográfica foi aprimorada com os dados geoquímicos, especialmente quanto aos teores de MgO, SiO2 e CaO e sua distribuição. Nos mármores de Caçapava do Sul, há predomínio de dolomita, corroborado pelo teor de MgO (17,66 a 21,52%) e classificados como dolomíticos. Na região de Arroio Grande, domina calcita, com concentrações de MgO entre 0,44 e 0,54% e os mármores são classificados como calcíticos. Os teores de CaO ficaram entre 26,24 e 31,59% nos mármores de Caçapava do Sul e entre 51,37 e 53,24% no mármore de Arroio Grande, complementando a afirmação anterior. Essa diferença foi percebida também nos resultados dos ETRs, tanto na avaliação do comportamento geral destes elementos, quanto na avaliação de anomalias individuais (Ce e Eu), que indicaram componente marinho nos mármores Matarazzo e presença de processos envolvendo contribuição de fluidos hidrotermais nas rochas Fida e Inducal. Essa contribuição de fluidos posteriores e não originais foi observada, também, com a avaliação das razões Mn/Sr, Sr/Ca e os teores de MnO e Sr. As razões 87Sr/86Sr variam entre 0,704 e 0,713 para os mármores Fida; 0,709 e 0,714 para Mudador; 0,705 e 0,709 para Inducal e 0,7060 e 0,7067 para Matarazzo. O mármore Matarazzo é o que possui os valores mais próximos da composição original, sendo o que possui o resultado original mais confiável; o mármore Inducal apresenta resultados que demonstram composição original questionável, mas ainda dentro do campo aceitável pela literatura; e as rochas Fida e Mudador não apresentaram condições confiáveis nesse sentido. Os resultados interpretados sugerem que a formação dos mármores de Arroio Grande ocorreu entre 900 e 850 Ma e Caçapava do Sul entre 800 e 750 Ma, em ambientes deposicionais distintos. / The Sul-Rio-Grandense Shield is an important element of southern Brazil geology. It includes few known marble occurrences in its geotectonic domains. In order to understand better the local stratigraphy, geological setting and regional evolution, four quarries were selected in two distinct geotectonic domains: Fida, Mudador and Inducal quarries located at around Caçapava do Sul (RS) city– São Gabriel Terrain –; Matarazzo quarry at around Arroio Grande (RS) region – Pelotas Batholith. Methodology includes petrography, geochemistry and Sr isotopes analysis, applied in 38 samples from 91 collected in four studied areas. Rocks classification through the results of petrographic analysis was enhanced by geochemistry data, especially when it comes to MgO, SiO2 and CaO contents and their distribution. Caçapava do Sul marbles show dolomite predominance, since this data is corroborated by the MgO content (17.66 to 21.52%) and it is classified as dolomitic. At the Arroio Grande region, calcite prevails, and the MgO content ranges between 0.44 and 0.54% and the marbles are classified as calcitic. Caçapava do Sul marbles include CaO contents ranging between 26.24 and 31.59% whereas Arroio Grande marble ranges between 51.37 and 53.24%, complementing the previous statement. This difference was also observed in the REE’s results, as much in evaluation of the general behavior of these elements as in evaluation of individual anomalies (Ce and Eu), which indicate a marine component on Matarazzo marbles and the presence of processes involving contribution of hydrothermal fluids on Fida and Inducal rocks. This contribution of posterior fluids and non original fluids was also observed with the evaluation of Mn/Sr, Sr/Ca ratios and MnO and Sr contents. The 87Sr/86Sr ratios range from 0.704 to 0.713 on the Fida marbles; 0.709 to 0.714 on Mudador; 0.705 to 0.790 on Inducal and from 0.7060 to 0.7067 on Matarazzo. Matarazzo marble is the only rock that has the closest values compared to the original composition, and it is only one that has the most reliable original result; Inducal marble shows results that demonstrate dubious values when compared to original composition, but still within the acceptable field according to the literature; Fida and Mudador rocks do not present reliable conditions in this regard. Interpreted results suggest that Arroio Grande marbles were generated between 900 and 850 Ma whereas Caçapava do Sul marbles between 800 and 750 Ma. Both of them were developed under different depositional environments.

O Escudo Sul-Rio-Grandense, importante elemento da geologia do sul do Brasil, possui, em seus diferentes domínios geotectônicos, ocorrências de mármores que foram relativamente pouco estudadas. Sabendo da importância dessas rochas para um maior entendimento da estratigrafia, do contexto de formação e evolução regional, foram escolhidas quatro pedreiras em dois domínios geotectônicos distintos: Fida, Mudador e Inducal na região de Caçapava do Sul (RS) – Terreno São Gabriel – e Matarazzo na região de Arroio Grande (RS) – Batólito Pelotas. A metodologia empregada no trabalho incluiu análises de petrografia, geoquímica e isótopos de Sr, aplicadas em 38 amostras dentre as 91 coletadas nas quatro áreas de estudo. A classificação das rochas através dos resultados da análise petrográfica foi aprimorada com os dados geoquímicos, especialmente quanto aos teores de MgO, SiO2 e CaO e sua distribuição. Nos mármores de Caçapava do Sul, há predomínio de dolomita, corroborado pelo teor de MgO (17,66 a 21,52%) e classificados como dolomíticos. Na região de Arroio Grande, domina calcita, com concentrações de MgO entre 0,44 e 0,54% e os mármores são classificados como calcíticos. Os teores de CaO ficaram entre 26,24 e 31,59% nos mármores de Caçapava do Sul e entre 51,37 e 53,24% no mármore de Arroio Grande, complementando a afirmação anterior. Essa diferença foi percebida também nos resultados dos ETRs, tanto na avaliação do comportamento geral destes elementos, quanto na avaliação de anomalias individuais (Ce e Eu), que indicaram componente marinho nos mármores Matarazzo e presença de processos envolvendo contribuição de fluidos hidrotermais nas rochas Fida e Inducal. Essa contribuição de fluidos posteriores e não originais foi observada, também, com a avaliação das razões Mn/Sr, Sr/Ca e os teores de MnO e Sr. As razões 87Sr/86Sr variam entre 0,704 e 0,713 para os mármores Fida; 0,709 e 0,714 para Mudador; 0,705 e 0,709 para Inducal e 0,7060 e 0,7067 para Matarazzo. O mármore Matarazzo é o que possui os valores mais próximos da composição original, sendo o que possui o resultado original mais confiável; o mármore Inducal apresenta resultados que demonstram composição original questionável, mas ainda dentro do campo aceitável pela literatura; e as rochas Fida e Mudador não apresentaram condições confiáveis nesse sentido. Os resultados interpretados sugerem que a formação dos mármores de Arroio Grande ocorreu entre 900 e 850 Ma e Caçapava do Sul entre 800 e 750 Ma, em ambientes deposicionais distintos. / The Sul-Rio-Grandense Shield is an important element of southern Brazil geology. It includes few known marble occurrences in its geotectonic domains. In order to understand better the local stratigraphy, geological setting and regional evolution, four quarries were selected in two distinct geotectonic domains: Fida, Mudador and Inducal quarries located at around Caçapava do Sul (RS) city– São Gabriel Terrain –; Matarazzo quarry at around Arroio Grande (RS) region – Pelotas Batholith. Methodology includes petrography, geochemistry and Sr isotopes analysis, applied in 38 samples from 91 collected in four studied areas. Rocks classification through the results of petrographic analysis was enhanced by geochemistry data, especially when it comes to MgO, SiO2 and CaO contents and their distribution. Caçapava do Sul marbles show dolomite predominance, since this data is corroborated by the MgO content (17.66 to 21.52%) and it is classified as dolomitic. At the Arroio Grande region, calcite prevails, and the MgO content ranges between 0.44 and 0.54% and the marbles are classified as calcitic. Caçapava do Sul marbles include CaO contents ranging between 26.24 and 31.59% whereas Arroio Grande marble ranges between 51.37 and 53.24%, complementing the previous statement. This difference was also observed in the REE’s results, as much in evaluation of the general behavior of these elements as in evaluation of individual anomalies (Ce and Eu), which indicate a marine component on Matarazzo marbles and the presence of processes involving contribution of hydrothermal fluids on Fida and Inducal rocks. This contribution of posterior fluids and non original fluids was also observed with the evaluation of Mn/Sr, Sr/Ca ratios and MnO and Sr contents. The 87Sr/86Sr ratios range from 0.704 to 0.713 on the Fida marbles; 0.709 to 0.714 on Mudador; 0.705 to 0.790 on Inducal and from 0.7060 to 0.7067 on Matarazzo. Matarazzo marble is the only rock that has the closest values compared to the original composition, and it is only one that has the most reliable original result; Inducal marble shows results that demonstrate dubious values when compared to original composition, but still within the acceptable field according to the literature; Fida and Mudador rocks do not present reliable conditions in this regard. Interpreted results suggest that Arroio Grande marbles were generated between 900 and 850 Ma whereas Caçapava do Sul marbles between 800 and 750 Ma. Both of them were developed under different depositional environments.

Sandby borg, an Iron Age ringfort on Öland, Sweden has been and is still at the center of attention in media and archaeological research. The massacre uncovered at the site during recent years opens many doors for analyses on the Migration Period (c. 400-550 AD) Iron Age skeletal remains. Eighteen teeth (molars) from 12 individuals and three rodent teeth were chosen for strontium (87Sr/86Sr) analyses. This was done to establish whether these individuals were locals or non-locals to Öland. The analyses displayed a, for the most part, local 87Sr/86Sr ratio. Two non-locals were identified, as well as a pattern of higher 87Sr/86Sr peaks on numerous of the individuals during a certain age span, which could indicate a local weaning process with a special food. / Sandby borg

Les spéléothèmes (concrétions carbonatées se formant dans les zones karstiques) sont des archives paleo-climatiques reconnues, dont l'intérêt majeur est de pouvoir être datées précisément par la méthode Uranium-Thorium. En revanche, les traceurs traditionnellement utilisés pour reconstruire les climats passés à partir de ces objets géologiques ne sont pas directement quantifiables en termes de paramètres climatiques comme la température moyenne, ou la quantité de précipitation. Les variations des concentrations en éléments traces contenus dans les spéléothèmes ont pu être relié dans certains sites aux changements climatiques passés, mais des doutes existent sur la robustesse de leur signal au sein d'une même grotte et entre différents sites.Nous nous sommes appliqués à déterminer les variations au cours des 50 000 dernières années de plusieurs catégories d'éléments (alcalino-terreux, uranium, et terres rares) dans des stalagmites de deux grottes situées dans le sud de la France (les grottes de Villars en Dordogne et de Chauvet en Ardèche), par spectrométrie ICP-MS. Les spéléothèmes sélectionnés ont déjà été datés et ont enregistré les variations paleo-environnementales à travers les isotopes stables de la calcite. Trois périodes d'étude caractérisées par des changements particuliers sont étudiées: le stade isotopique 3 de la dernière période glaciaire (~50-30 ka), la dernière déglaciation (~20-10 ka) et la fin de l'Holocène (~2-0 ka).Le signal des variations des alcalino-terreux à Villars pendant le stade isotopique 3 est significatif et robuste. La variabilité du strontium notamment, qui provient de processus hydrologiques intra-karst, suit les événements climatiques rapides enregistrés dans l'hémisphère Nord. D'autre part, le comportement de nombreux éléments traces pendant la déglaciation est similaire entre les grottes de Villars et de Chauvet. Enfin, des changements du couvert végétal sont probablement à l'origine des changements synchrones enregistrés par les éléments traces et les isotopes stables de la calcite au cours des deux derniers millénaires à Villars.Par ailleurs, l'étude des coefficients de partition des alcalino-terreux, de l'uranium et des terres rares dans des conditions variées montre l'importante de la variabilité inter-site de leur partitionnement.

No / The excavation at Cnip, Isle of Lewis, Scotland of the largest, and only known family cemetery from the early Norse period in the Hehrides, provided a unique opportunity to use Sr isotope analysis to examine the origins of people who may have been Norwegian Vikings. Sr isotope analysis permits direct investigation of a person's place of origin rather than indirectly through acquired cultural and artefactual affiliations. Sr isotope data suggest that the Norse group at Cnip was of mixed origins. The majority were consistent with indigenous origins but two individuals, of middle-age and different sex. were immigrants. They were, however, not from Norway but were raised separately, most probably on Tertiary volcanic rocks (e.g. the Inner Hebrides or NE Ireland) or, for the female, on marine carbonate rocks.

La premier thématique a pour objectifs :1) de tracer l’origine de la salinité des eaux des aquifères karstiques en milieu côtier méditerranéen,2) de quantifier les proportions de mélange entre les eaux salées et les eaux karstiques,3) de discriminer les traceurs géochimiques pour identifier et modéliser les processus de salinisation d’aquifères karstiques côtiers. La seconde thématique a pour objectifs:1) d’établir les [As] d’origine naturelle des eaux de surface et des eaux souterraines, 2) de quantifier le niveau de contamination en arsenic de ces eaux et sa variabilité spatio-temporelle 3) de tracer l’origine naturelle ou anthropique de la pollution en As à l’aide d’outils isotopiques adaptés. les origines de la salinité identifié inclue i) des venues d’eaux profondes salées ii) des venues profondes d’eau salées remontant vers la surface par une faille majeure normale. Le 36Cl/Cl a permis d’identifier l’origine profonde des eaux salées et une recharge d’eau météorique infiltrée lors de la période des essais thermonucléaires. La modélisation PHREEQC permet de différentier le mélange avec une eau profonde salée de celui avec une eau de mer actuelle. Le 87Sr/86Sr montre un comportement conservatif pour tracer l’origine des eaux salées dans les aquifères karstiques. Les traceurs Cs, Rb, Li et B permettent de différentier les trois origines identifiées de la salinité. Les données acquises sur la contamination en As soulignent une augmentation nette et pérenne des [As] à partir des anciens sites de traitement minier réhabilités. Les rapports 87Sr/86Sr et δ18O et δ2H se révèlent dans ce cas un traceur très discriminant de l’origine naturelle ou anthropique de l’arsenic. / The first theme has for objectives: 1) to trace the origin of the salinity of the waters of the karst aquifers in coastal environment mediterraneen,2) to quantify the mixing proportions between salt waters and the waters karstiques,3) to discriminate the geochemical tracers to identify and model the process of salinization of aquifers coastal karst. The second theme has for objectives:1) to establish the [hast] of natural origin of surface waters and groundwater, 2) to quantify the level of contamination by arsenic in these waters and its spatial and temporal variability 3) to trace the natural or anthropogenic origin of pollution in hast to the aid of isotopic tools adapted. the origins of the salinity identified include i) of came from deep waters salted ii) of come deep water salted dating back toward the surface by a major flaw normal. The 36Cl/Cl has allowed us to identify the origin of deep saline waters and a recharge of meteoric water infiltrated during the period of thermonuclear tests. The PHREEQC modeling used to differentiate between the mixture with a deep water of salt that one with a sea water current. The 87SR/ 86Sr shows a conservative behavior for tracing the origin of saline waters in karst aquifers. The plotters Cs, Rb, Li and B allows to differentiate the three origins identified of salinity. The data acquired on the contamination in hast underline a net increase and perennial of [hast] from the ancient sites of mining processing rehabilitated. The reports 87SR/ 86Sr and δ18O and δ2H will reveal in this case a chartplotter very discriminant of natural or anthropogenic origin of arsenic.