Consulta: creatorFacets:"Ponzevera, Emmanuel"
Registros recuperados: 42
Data/hora: 05/06/2024 18:13:31

Determination of ultra-low U-236/U-238 isotope ratios by tandem quadrupole ICP-MS/MS
Provedor de dados: 5
Autores: Tanimizu, Masaharu; Sugiyama, Naoki; Ponzevera, Emmanuel; Bayon, Germain.
Isotope ratios of U-236/U-238 were measured at levels below 10(-7) by single collector ICPMS with a tandem quadrupole mass separation mechanism. Peak tailing of the prominent U-238(+) ion beam on the U-236(+) peak was reduced to the level of similar to 10(-10) by use of two quadrupole mass filters. The (UH+)-U-235 interference on U-236(+) was efficiently reduced to a UH+/U+ ratio of 1 x 10(-8) by an ion-molecule reaction between UH+ and O-2 in a collision/reaction cell placed between the two quadrupoles. The resultant detection limit for U-236/U-238 measurement was better than those reported by any other ICPMS study. The U-236/U-238 ratios, measured as (UO+)-U-236-O-16/(UO+)-U-238-O-16, were determined in the range 10(-9) to 10(-7) without correction for...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00152/26358/24440.pdf

Nuclear field shift effect in isotope fractionation of thallium
Provedor de dados: 5
Autores: Fujii, Toshiyuki; Moynier, Frederic; Agranier, Arnaud; Ponzevera, Emmanuel; Abe, Minori; Uehara, Akihiro; Yamana, Hajimu.
Environmental transport of Tl is affected by redox reaction between Tl(I) and Tl(III) and ligand exchange reactions of them. In order to deepen the knowledge of Tl chemistry, we investigated fractionation of Tl stable isotopes (Tl-203 and Tl-205) in a chemical exchange system. Tl isotopes were fractionated in a liquid-liquid extraction system, in which aqueous and organic phases are hydrochloric acid solution and dichloroethane including a crown ether, respectively. After purification by ion-exchange chemistry, the isotope ratio of Tl-205/Tl-203 in equilibrated aqueous phase was measured precisely by multiple-collector-inductively-coupled-plasma-mass-spectrometry. A large isotope fractionation &gt; 1 aEuro degrees was found. Electronic structures of...
Tipo: Text
Palavras-chave: Thallium; Isotope fractionation; Redox; Ligand exchange; Nuclear field shift; Ab initio calculation.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00135/24624/22691.pdf

GEOTRACES inter-calibration of the stable silicon isotope composition of dissolved silicic acid in seawater
Provedor de dados: 5
Autores: Grasse, Patricia; Brzezinski, Mark A.; Cardinal, Damien; De Souza, Gregory F.; Andersson, Per; Closset, Ivia; Cao, Zhimian; Dai, Minhan; Ehlert, Claudia; Estrade, Nicolas; Francois, Roger; Frank, Martin; Jiang, Guibin; Jones, Janice L.; Kooijman, Ellen; Liu, Qian; Lu, Dawei; Pahnke, Katharina; Ponzevera, Emmanuel; Schmitt, Melanie; Sun, Xiaole; Sutton, Jill; Thil, Francois; Weis, Dominique; Wetzel, Florian; Zhang, Anyu; Zhang, Jing; Zhang, Zhouling.
The first inter-calibration study of the stable silicon isotope composition of dissolved silicic acid in seawater, delta Si-30(OH)(4), is presented as a contribution to the international GEOTRACES program. Eleven laboratories from seven countries analyzed two seawater samples from the North Pacific subtropical gyre (Station ALOHA) collected at 300 m and at 1000 m water depth. Sampling depths were chosen to obtain samples with a relatively low (9 mmol L-1, 300 m) and a relatively high (113 mmol L-1, 1000 m) silicic acid concentration as sample preparation differs for low- and highconcentration samples. Data for the 1000 m water sample were not normally distributed so the median is used to represent the central tendency for the two samples. Median delta...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00381/49270/49681.pdf

Production and certification of candidate Pb delta-iCRMs ERM-3800 and ERM-3810 series
Provedor de dados: 5
Autores: Ponzevera, Emmanuel; Quetel, Christophe R.; Hendrickx, Frans; Fortunato, Giuseppino.
This paper describes the preparation of a new type of Pb delta-isotopic Certified Reference Materials (delta-iCRMs), available in liquid form (Pb mass fraction similar to 100 mu g g(-1), 2 mL, 3% HNO3) to prevent the risk of insufficient isotopic homogeneity. These materials are intended for the validation of delta-scale isotope ratio measurements, and come in four pairs. The quantities certified are the relative differences on values of n(Pb-207)/n(Pb-204), n(Pb-207)/n(Pb-206) and n(Pb-207)/n(Pb-208) ratios between the members of each pair. There is a material with similar to natural Pb-isotopic composition (ERM-3800, delta-0 material), common to all pairs, and the same similar to natural Pb progressively enriched in Pb-207 (ERM-3810 series). Pairs I to...
Tipo: Text
Ano: 2009

Hf and Nd isotope records of West African monsoon precipitation in sediments from the Niger Delta
Provedor de dados: 5
Autores: Bayon, Germain; Etoubleau, Joel; Ponzevera, Emmanuel; Voisset, Michel.
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00023/13413/10490.pdf

Measuring 0.01 parts per thousand to 0.1 parts per thousand isotopic variations by MC-ICPMS-testing limits for the first time with Pb delta-iCRMs
Provedor de dados: 5
Autores: Quetel, Christophe R.; Ponzevera, Emmanuel; Rodushkin, Ilia; Gerdes, Axel; Williams, Ross; Woodhead, Jon.
A blind comparison on Pb-isotope delta-scale measurements by MC-ICPMS of 0.01 parts per thousand to 0.1 parts per thousand level was organised, involving five laboratories. Test samples were obtained from the series of candidate ERM-3810 delta-isotopic Certified Reference Materials (delta-iCRMs), and comprise four pairs of a material with similar to natural Pb-isotopic composition ('delta zero' or 'delta-0') and the same natural Pb progressively enriched in Pb-207 (with delta Pb-207 values certified to similar to 0.1% relative uncertainty, k = 2). Participants were free to apply the measurement strategy of their choice. A result was considered 'acceptable' only when, simultaneously, there was agreement within stated uncertainties with the corresponding...
Tipo: Text
Ano: 2009

The roles of climate and human land-use in the late Holocene rainforest crisis of Central Africa
Provedor de dados: 5
Autores: Bayon, Germain; Schefuss, Enno; Dupont, Lydie; Borges, Alberto V.; Dennielou, Bernard; Lambert, Thibault; Mollenhauer, Gesine; Monin, Laurence; Ponzevera, Emmanuel; Skonieczny, Charlotte; Andre, Luc.
There is increasing evidence that abrupt vegetation shifts and large-scale erosive phases occurred in Central Africa during the third millennium before present. Debate exists as to whether these events were caused by climate change and/or intensifying human activities related to the Bantu expansion. In this study, we report on a multi-proxy investigation of a sediment core (KZR-23) recovered from the Congo submarine canyon. Our aim was to reconstruct climate, erosion and vegetation patterns in the Congo Basin for the last 10,000 yrs, with a particular emphasis on the late Holocene period. Samples of modern riverine suspended particulates were also analyzed to characterize sediment source geochemical signatures from across the Congo watershed. We find that...
Tipo: Text
Palavras-chave: Neodymium isotopes; Suspended particulates; Congo Basin; ENSO; Human land-use; Deforestation.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00463/57467/59747.pdf

Sulfur and strontium isotopic study of epithermal mineralization: A case study from the SE Afar Rift, Djibouti
Provedor de dados: 5
Autores: Moussa, N.; Rouxel, Olivier; Grassineau, N. V.; Ponzevera, Emmanuel; Nonnotte, P.; Fouquet, Yves; Le Gall, B.
Epithermal mineralization was recently described in synrift volcanic rocks from the SE Afar Rift in Djibouti. To infer fluid sources in this system, coupled sulfur and strontium isotopic analyses were performed on mineralized samples from hydrothermal veins and stockwork zones. Mineralization includes gypsum and chalcedony, and/or quartz ± carbonate containing gold and sulfides. Sulfur isotopic compositions of sulfides and sulfates were determined using Multicollector-Inductively Coupled Plasma Mass Spectrometer (MC ICPMS); Laser Ablation MC ICPMS; and Continuous Flow Elemental Analyzer-Isotope Ratio Mass Spectrometry while strontium isotopes were determined by Thermal Ionisation Mass Spectrometry (TIMS) methods. Sulfur isotopic composition of sulfides...
Tipo: Text
Palavras-chave: Hydrothermal system; Sulfur isotopes; Strontium isotopes; SE Afar rift; Epithermal.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00356/46712/46581.pdf

SCOTTTI (2018-2019) : Etude des Sources des COntaminants et de leurs Transferts vers le réseau Trophique par des Traceurs Innovants
Provedor de dados: 5
Autores: Knoery, Joel; Briant, Nicolas; Chouvelon, Tiphaine; Gonzalez, Jean-louis; Ponzevera, Emmanuel; Brach-papa, Christophe; Brochen, Michelle; Bruzac, Sandrine; Crochet, Sylvette; De Vogue, Benoist; Marco-miralles, Francoise; Ravel, Christophe; Sireau, Teddy; Thomas, Bastien.
Ce rapport présente les résultats de l’étude exploratoire SCOTTTI soutenue par l’Agence de l’Eau Rhône Méditerranée Corse. Ce travail vise à étudier les sources de contaminants et leurs transferts au sein des réseaux trophiques des zones littorales par l’utilisation de traceurs et d’outils innovants à partir d’une application au site atelier de la rade de Toulon. Les travaux engagés se décomposent en 3 volets. Le premier (réseaux trophiques, RT) vise à tracer le passage des contaminants métalliques entre les différents compartiments biogéochimiques de la rade de Toulon, et aussi à en caractériser les teneurs spécifiques en utilisant des traceurs et marqueurs du fonctionnement des RT (combinaison de l’utilisation des profils lipidiques...
Tipo: Text
Palavras-chave: Rade de Toulon contaminants (Cu; Pb; Hg) isotopie du cuivre isotopie du mercure transferts trophiques.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00495/60677/64193.pdf

δ11B as monitor of calcification site pH in divergent marine calcifying organisms
Provedor de dados: 5
Autores: Sutton, Jill N.; Liu, Yi-wei; Ries, Justin B.; Guillermic, Maxence; Ponzevera, Emmanuel; Eagle, Robert A.
The boron isotope composition (δ11B) of marine biogenic carbonates has been predominantly studied as a proxy for monitoring past changes in seawater pH and carbonate chemistry. However, a number of assumptions regarding chemical kinetics and thermodynamic isotope exchange reactions are required to derive seawater pH from δ11B biogenic carbonates. It is also probable that δ11B of biogenic carbonate reflects seawater pH at the organism's site of calcification, which may or may not reflect seawater pH. Here, we report the development of methodology for measuring the δ11B of biogenic carbonate samples at the multi-collector inductively coupled mass spectrometry facility at Ifremer (Plouzané, France) and the evaluation of δ11BCaCO3 in a diverse range of marine...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00430/54152/55481.pdf

An Intercomparison Study of the Germanium Isotope Composition of Geological Reference Materials
Provedor de dados: 5
Autores: Escoube, Raphalle; Rouxel, Olivier; Luais, Beatrice; Ponzevera, Emmanuel; Donard, Olivier F. X.
Recent analytical developments in germanium stable isotope determination by multicollector ICP-MS have provided new perspectives for the use of Ge isotopes as geochemical tracers. Here, we report the germanium isotope composition of the NIST SRM 3120a elemental reference solution that has been calibrated relative to internal isotopic standard solutions used in the previous studies. We also intercalibrate several geological reference materials as well as geological and meteoritic samples using different techniques, including online hydride generation and a spray chamber for sample introduction to MC-ICP-MS, and different approaches for mass bias corrections such as samplecalibrator bracketing, external mass bias correction using Ga isotopes and double-spike...
Tipo: Text
Palavras-chave: Germanium; Isotope; Intercalibration; Reference materials; Germanium; Isotope; Intercalibration; Materiaux de reference.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00089/20036/21743.pdf

Copper, zinc and lead isotope signatures of sediments from a mediterranean coastal bay impacted by naval activities and urban sources
Provedor de dados: 5
Autores: Ferreira Araujo, Daniel; Ponzevera, Emmanuel; Briant, Nicolas; Knoery, Joel; Bruzac, Sandrine; Sireau, Teddy; Brach-papa, Christophe.
Toulon bay is severely impacted by metal contamination induced by past and recent naval activities. In this work, Cu, Zn and Pb isotope compositions and elemental concentrations of fifty-five surface sediments were determined in order to map the spatial distribution of anthropogenic and natural sources along this land-sea continuum. Two sub-systems of Toulon Bay, the Small and Large bays, showed well-marked patterns on metal contamination levels and isotope signatures for Cu and Pb. The Small bay had the highest metal concentrations, and displayed average Pb and Cu isotope compositions of 1.1664 ± 0.0043 (1s, expressed as 206Pb/207Pb ratios) and −0.17 ± 0.19‰ (1s, expressed as δ65CuNIST values), respectively. It contrasted with the Large bay, with moderate...
Tipo: Text
Palavras-chave: Metal isotopes; Isotope tracers; Geochemical isotopes; Environmental pollution; Coastal pollution; Toulon bay.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00566/67784/67226.pdf

Pore water geochemistry at two seismogenic areas in the Sea of Marmara
Provedor de dados: 5
Autores: Ruffine, Livio; Germain, Yoan; Polonia, Alina; De Prunele, Alexis; Croguennec, Claire; Donval, Jean-pierre; Pitel-roudaut, Mathilde; Ponzevera, Emmanuel; Caprais, Jean-claude; Brandily, Christophe; Grall, Celine; Bollinger, Claire; Geli, Louis; Gasperini, Luca.
Within the Sea of Marmara, the highly active North Anatolian Fault (NAF) is responsible for major earthquakes (Mw&gt;=7), and acts as a pathway for fluid migration from deep sources to the seafloor. This work reports on pore water geochemistry from three sediment cores collected in the Gulfs of Izmit and Gemlik, along the Northern and the Middle strands of the NAF, respectively. The resulting data set shows that anaerobic oxidation of methane (AOM) is the major process responsible for sulfate depletion in the shallow sediment. In the Gulf of Gemlik, depth concentration profiles of both sulfate and alkalinity exhibit a kink-type profile. The Sulfate Methane Transition Zone (SMTZ) is located at moderate depth in the area. In the Gulf of Izmit, the low...
Tipo: Text
Palavras-chave: Anaerobic oxidation of methane; North Anatolian Fault; Pore water geochemistry; Sea of Marmara; Seismic activity.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00272/38339/36570.pdf

Iron isotope fractionation in iron-organic matter associations: Experimental evidence using filtration and ultrafiltration
Provedor de dados: 5
Autores: Lotfi-kalahroodi, Elaheh; Pierson-wickmann, Anne-catherine; Guénet, Hélène; Rouxel, Olivier; Ponzevera, Emmanuel; Bouhnik-lecoz, Martine; Vantelon, Delphine; Dia, Aliou; Davranche, Mélanie.
Colloids have been recognized as key vectors of pollutants in aqueous environment. Amongst them, those formed by iron (Fe) and organic matter (OM) are of major importance due to their ubiquity in the surface environment and strong affinity for metals. In the recent years, Fe stable isotopes have been increasingly used to elucidate the sources and biogeochemical cycling of Fe in Earth's surface environments. In this study, we aim to elucidate (i) the possible Fe isotopic signature resulting from the Fe/OM colloid formation and (ii) the mechanisms involved in the development of such isotopic signature. For this purpose, Fe-OM associations were synthesized through binding and titration experiments. Various pH levels were used in order to study the isotope...
Tipo: Text
Palavras-chave: Filtration; Size fractionation; Isotope fractionation; Colloidal; Dissolved; Fe isotopes.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00480/59174/61811.pdf

Total dissolvable and dissolved iron isotopes in the water column of the Peru upwelling regime
Provedor de dados: 5
Autores: Chever, Fanny; Rouxel, Olivier; Croot, Peter L.; Ponzevera, Emmanuel; Wuttig, Kathrin; Auro, Maureen.
Vertical distributions of iron (Fe) concentrations and isotopes were determined in the total dissolvable and dissolved pools in the water column at three coastal stations located along the Peruvian margin, in the core of the Oxygen Minimum Zone (OMZ). The shallowest station 121 (161 m total water depth) was characterized by lithogenic input from the continental plateau, yielding concentrations as high as 456 nM in the total dissolvable pool. At the 2 other stations (stations 122 and 123), Fe concentrations of dissolved and total dissolvable pools exhibited maxima in both surface and deep layers. Fe isotopic composition (δ56Fe) showed a fractionation toward lighter values for both physical pools throughout the water column for all stations with minimum...
Tipo: Text
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00266/37715/35733.pdf

The silicon isotopic composition of fine-grained river sediments and its relation to climate and lithology
Provedor de dados: 5
Autores: Bayon, Germain; Delvigne, C.; Ponzevera, Emmanuel; Borges, A. V.; Darchambeau, F.; De Deckker, P.; Lambert, T.; Monin, L.; Toucanne, Samuel; Andre, L.
The δ30Si stable isotopic composition of silicon in soils and fine-grained sediments can provide insights into weathering processes on continents, with important implications on the Si budget of modern and past oceans. To further constrain the factors controlling the distribution of Si isotopes in sediments, we have analysed a large number (n=50) of separate size-fractions of sediments and suspended particulate materials collected near the mouth of rivers worldwide. This includes some of the world’s largest rivers (e.g. Amazon, Congo, Mackenzie, Mississippi, Murray-Darling, Nile, Yangtze) and rivers from the case study areas of the Congo River Basin and Northern Ireland. Silt-size fractions exhibit a mean Si isotopic composition (δ30Si = -0.21 ± 0.19‰; 2...
Tipo: Text
Palavras-chave: World rivers; Congo basin; Northern Ireland; Si isotopes; Clay minerals; Weathering; Temperature; Precipitation.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00434/54609/55991.pdf

Nickel Isotope Variations in Terrestrial Silicate Rocks and Geological Reference Materials Measured by MC-ICP-MS
Provedor de dados: 5
Autores: Gueguen, Bleuenn; Rouxel, Olivier; Ponzevera, Emmanuel; Bekker, Andrey; Fouquet, Yves.
Although initial studies have demonstrated the applicability of Ni isotopes for cosmochemistry and as a potential biosignature, the Ni isotope composition of terrestrial igneous and sedimentary rocks, and ore deposits remains poorly known. Our contribution is fourfold: (a) to detail an analytical procedure for Ni isotope determination, (b) to determine the Ni isotope composition of various geological reference materials, (c) to assess the isotope composition of the Bulk Silicate Earth relative to the Ni isotope reference material NIST SRM 986 and (d) to report the range of mass-dependent Ni isotope fractionations in magmatic rocks and ore deposits. After purification through a two-stage chromatography procedure, Ni isotope ratios were measured by MC-ICP-MS...
Tipo: Text
Palavras-chave: Nickel; Stable isotopes; MC-ICP-MS; Geological reference materials; Bulk Silicate Earth; Abiotic fractionation.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00159/27069/25332.pdf

The behavior of nickel isotopes at the biogeochemical interface between ultramafic soils and Ni accumulator species
Provedor de dados: 5
Autores: Ratie, G.; Quantin, C.; Maia De Freitas, A.; Echevarria, G.; Ponzevera, Emmanuel; Garnier, J.
Ultramafic derived soils are characterized by low nutrient soils, a low Ca:Mg ratio, and high metal contents such as Ni, Co and Cr. The vegetation growing on these soils is highly adapted and includes both Ni hyperaccumulator and accumulator species. Today, approximately 530 Ni hyperaccumulator species are listed worldwide and the Ni concentration can be extremely high, e.g. up to 25% in latex from Pycnandra acuminata (Sapotaceae), a tree found in New Caledonia. The aim of this study is to identify the potential role of Ni hyperaccumulator plants in the Ni biogeochemical cycle at the soil surface by using Ni isotopes. A set of Ni hyperaccumulator and Ni accumulator plants as well as topsoils were sampled on the Barro Alto and Niquelândia ultramafic...
Tipo: Text
Palavras-chave: Nickel; Isotope; Ni hyperaccumulator species; Ultramafic environment.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00464/57565/59740.pdf

Formation of carbonate chimneys in the Mediterranean Sea linked to deep-water oxygen depletion
Provedor de dados: 5
Autores: Bayon, Germain; Dupre, Stephanie; Ponzevera, Emmanuel; Etoubleau, Joel; Cheron, Sandrine; Pierre, Catherine; Mascle, Jean; Boetius, Antje; De Lange, Gert J.
Marine sediments at ocean margins vent substantial amounts of methane(1,2). Microbial oxidation of the methane released can trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems(3,4). The factors controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid over geological time remain poorly constrained. Here, we characterize the petrology and geochemistry of rocks sampled from metre-size build-ups of methane-derived carbonate chimneys located at the Amon mud volcano on the Nile deep-sea fan. We find that these carbonates comprise porous structures composed of aggregated spherules of aragonite, and closely resemble microbial carbonate reefs forming at present...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00156/26734/24854.pdf

Response to Comments on "Intensifying Weathering and Land Use in Iron Age Central Africa"
Provedor de dados: 5
Autores: Bayon, Germain; Dennielou, Bernard; Etoubleau, Joel; Ponzevera, Emmanuel; Toucanne, Samuel; Bermell, Sylvain.
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00092/20327/18004.pdf

Comparative geochemistry of four ferromanganese crusts from the Pacific Ocean and significance for the use of Ni isotopes as paleoceanographic tracers
Provedor de dados: 5
Autores: Gueguen, Bleuenn; Rouxel, Olivier; Rouget, Marie-laure; Bollinger, Claire; Ponzevera, Emmanuel; Germain, Yoan; Fouquet, Yves.
Ferromanganese (Fe-Mn) crusts are potential archive of the Ni isotope composition of seawater through time. In this study we aim at (1) understanding Ni isotope fractionation mechanisms and metal enrichment processes in Fe-Mn deposits, (2) addressing global vs. local control of Ni isotope composition of these deposits. Two Fe-Mn crusts from the North Pacific Ocean (Apuupuu Seamount, Hawaii) and two Fe-Mn crusts from the South Pacific Ocean (near Rurutu Island, Austral archipelago of French Polynesia) were characterized for their elemental geochemistry and Ni isotope composition. Geochemical analyses were performed at millimeter intervals in order to provide time-resolved record of Ni isotopes. Chronology and growth rates were determined using cosmogenic...
Tipo: Text
Palavras-chave: Ferromanganese crusts; Nickel isotopes; Paleoceanography; Pacific Ocean; Biogeochemical cycling.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00341/45255/44696.pdf

20 ans de suivi de la contamination chimique des eaux côtières méditerranéennes. Résultats &amp; perspectives
Provedor de dados: 5
Autores: Bouchoucha, Marc; Tomasino, Corinne; Amouroux, Isabelle; Andral, Bruno; Brach-papa, Christophe; Briand, Marine; Buchet, Remi; Delmas, Lucile; Galgani, François; Gonzalez, Jean-louis; Grouhel-pellouin, Anne; Mauffret, Aourell; Mille, Tiphaine; Munaron, Dominique; Ponzevera, Emmanuel; Wessel, Nathalie; Boissery, Pierre.
Ce rapport fait le bilan de la surveillance de la contamination chimique opérée par l’Ifremer, en partenariat avec l’agence de l’eau Rhône Méditerranée Corse, entre 1998 et 2018. Il présente sur la forme de graphiques et de cartes les principaux résultats obtenus durant cette période ainsi que l’évolution des méthodes et des stratégies de surveillance des eaux côtières de Méditerranée.
Tipo: Text
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00673/78554/80744.pdf

Environmental Hf–Nd isotopic decoupling in World river clays
Provedor de dados: 5
Autores: Bayon, Germain; Skonieczny, Charlotte; Delvigne, Camille; Toucanne, Samuel; Bermell, Sylvain; Ponzevera, Emmanuel; Andre, Luc.
The hafnium and neodymium radiogenic isotope systems behave differently during Earth surface processes, causing a wide dispersion of Hf and Nd isotopic compositions in sediments and other sedimentary rocks. The decoupling between Hf and Nd isotopes in sediments is generally attributed to a combination of preferential sorting of zircon during sediment transport and incongruent weathering processes on continents. In this study, we analysed size-fractions of sediment samples collected near the mouth of 53 rivers worldwide to better understand the factors controlling the distribution of Hf and Nd isotopes in sediments. Our results for rivers draining old cratonic areas and volcanic provinces demonstrate that both granite and basalt weathering can lead to...
Tipo: Text
Palavras-chave: Hafnium isotopes; Neodymium; Rivers; Clays; Weathering; Climate.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00310/42094/41479.pdf

Nickel distribution and isotopic fractionation in a Brazilian lateritic regolith: coupling Ni isotopes and Ni K-edge XANES.
Provedor de dados: 5
Autores: Ratie, G.; Garnier, J.; Calmels, D.; Vantelon, D.; Guimaraes, E.; Monvoisin, G.; Nouet, J.; Ponzevera, Emmanuel; Quantin, C.
Ultramafic (UM) rocks are known to be nickel (Ni) rich and to weather quickly, which makes them a good candidate to look at the Ni isotope systematics during weathering processes at the Earth’s surface. The present study aims at identifying the Ni solid speciation and discussing the weathering processes that produce Ni isotope fractionation in two deep laterite profiles under tropical conditions (Barro Alto, Goiás State, Brazil). While phyllosilicates and to a lower extent goethite are the main Ni-bearing phases in the saprolitic part of the profile, iron (Fe) oxides dominate the Ni budget in the lateritic unit. Nickel isotopic composition (δ60Ni values) has been measured in each unit of the regolith, i.e., rock, saprock, saprolite and laterite (n=52)....
Tipo: Text
Palavras-chave: Nickel cycle; Lateritic regolith; Nickel isotopes; XANES; Ultramafic environment; Weathering.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00436/54712/56149.pdf

Rare earth elements and neodymium isotopes in sedimentary organic matter
Provedor de dados: 5
Autores: Freslon, Nicolas; Bayon, Germain; Toucanne, Samuel; Bermell, Sylvain; Bollinger, Claire; Chéron, Sandrine; Etoubleau, Joel; Germain, Yoan; Khripounoff, Alexis; Ponzevera, Emmanuel; Rouget, Marie Laure.
We report rare earth element (REE) and neodymium (Nd) isotope data for the organic fraction of sediments collected from various depositional environments, i.e. rivers (n=25), estuaries (n=18), open-ocean settings (n=15), and cold seeps (n=12). Sedimentary Organic Matter (SOM) was extracted using a mixed hydrogen peroxide/nitric acid solution (20%-H2O2 – 0.02M-HNO3), after removal of carbonate and oxy-hydroxide phases with dilute hydrochloric acid (0.25M-HCl). A series of experimental tests indicate that extraction of sedimentary organic compounds using H202 may be complicated occasionally by partial dissolution of sulphide minerals and residual carbonates. However, this contamination is expected to be minor for REE because measured concentrations in H2O2...
Tipo: Text
Palavras-chave: Organic matter; Rare earth elements; REE; Neodymium isotopes; ΕNd; Sediment; Boundary Exchange; Paleoceanography.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00191/30250/28682.pdf

Behaviour of rare earth and trace elements during fluid venting at cold seeps
Provedor de dados: 5
Autores: Birot, Dominique; Bayon, Germain; Ruffine, Livio; Caprais, Jean-claude; Bollinger, C.; Ponzevera, Emmanuel; Rongemaille, Emmanuelle; Voisset, Michel.
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00023/13414/10493.pdf

Hf and Nd isotopes in marine sediments: Constraints on global silicate weathering
Provedor de dados: 5
Autores: Bayon, Germain; Burton, K. W.; Soulet, Guillaume; Vigier, N.; Dennielou, Bernard; Etoubleau, Joel; Ponzevera, Emmanuel; German, C. R.; Nesbitt, R. W.
The combined use of Lu-Hf and Sm-Nd isotope systems potentially offers a unique perspective for investigating continental erosion, but little is known about whether, and to what extent, the Hf-Nd isotope composition of sediments is related to silicate weathering intensity. In this study, Hf and Nd elemental and isotope data are reported for marine muds, leached Fe-oxide fractions and zircon-rich turbidite sands collected off the Congo River mouth, and from other parts of the SE Atlantic Ocean. All studied samples from the Congo fan (muds, Fe-hydroxides, sands) exhibit indistinguishable Nd isotopic composition (epsilon(Nd)similar to - 16), indicating that Fe-hydroxides leached from these sediments correspond to continental oxides precipitated within the...
Tipo: Text
Palavras-chave: Congo fan; Seawater array; Continental erosion; Silicate weathering; Hafnium isotopes; Neodymium isotopes.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6451.pdf

Paleo-environmental controls on cold seep carbonate authigenesis in the Sea of Marmara
Provedor de dados: 5
Autores: Cremiere, Antoine; Bayon, Germain; Ponzevera, Emmanuel; Pierre, Catherine.
The factors controlling fluid emission dynamics at ocean margins are poorly understood. In particular, there are significant uncertainties on how fluid seepage at cold seeps may have responded to abrupt environmental changes in the geological past. This study reports on a detailed geochemical investigation of seafloor carbonate crusts sampled at cold seeps along the submerged part of the North Anatolian Fault system in the Sea of Marmara - an inland sea, which has experienced major paleo-environmental changes over the last deglaciation period. We also analyzed a series of authigenic carbonate concretions recovered from two sediment cores at the Western-High ridge, an active fluid venting area. The ages of seafloor carbonate crusts derived from isochron...
Tipo: Text
Palavras-chave: U-Th dating; Authigenic carbonates; Sea of Marmara; Cold seeps; Sapropel event; Carbon and oxygen isotopes.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00161/27249/25488.pdf

The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean
Provedor de dados: 5
Autores: De La Rocha, Christina L.; Bescont, Pierre; Croguennoc, Alice; Ponzevera, Emmanuel.
We report here the silicon isotopic composition (delta(30)Si) of dissolved silicon (DSi) from 42 surface water samples from the Drake Passage, the Weddell Gyre, other areas south of the Southern Boundary of the Antarctic Circumpolar Current (ACC), and the ACC near the Kerguelen Plateau, taken between the beginning of February and the end of March 2007. From the beginning to end of the cruise (ANTXXIII/9), DSi diminished in the Antarctic by 50 mu mol L(-1) while concentrations of nitrate + nitrite and phosphate showed no net decline, indicating that the high seasonal Si/N removal ratios well known for the Southern Ocean may be more related to the strength of the silicate pump in the Southern Ocean than to the instantaneous Si/N uptake ratio of diatoms. The...
Tipo: Text
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00042/15372/12791.pdf

Nickel isotope fractionation during laterite Ni ore smelting and refining: implications for tracing the sources of Ni in smelter-affected soils
Provedor de dados: 5
Autores: Ratie, G.; Quantin, C.; Jouvin, D.; Calmels, D.; Ettler, V.; Sivry, Y.; Cruz Vieira, L.; Ponzevera, Emmanuel; Garnier, J.
Nickel isotope ratios were measured in ores, fly ash, slags and FeNi samples from two metallurgical plants located in the Goiás State, Brazil (Barro Alto, Niquelândia). This allowed investigating the mass-dependent fractionation of Ni isotopes during the Ni-laterite ore smelting and refining. Feeding material exhibits a large range of δ60Ni values (from 0.02 ± 0.10 ‰ to 0.20 ± 0.05 ‰, n=7), explained by the diversity of Ni-bearing phases, and the average of δ60Nifeeding materials was found equal to 0.08 ± 0.08‰ (2SD, n=7). Both δ60Ni values of fly ash (δ60Ni = 0.07 ± 0.07‰, n=10) and final FeNi produced (0.05 ± 0.02 ‰, n=2) were not significantly different from the feeding materials ones. These values are consistent with the very high production yield of...
Tipo: Text
Palavras-chave: Nickel; Isotope; Smelting; Refining; Source; Soil.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00278/38961/37501.pdf

Geochemical Dynamics of the Natural-Gas Hydrate System in the Sea of Marmara, Offshore Turkey
Provedor de dados: 5
Autores: Ruffine, Livio; Fandino Torres, Olivia; Etoubleau, Joel; Cheron, Sandrine; Donval, Jean-pierre; Germain, Yoan; Ponzevera, Emmanuel; Guyader, Vivien; Dennielou, Bernard; Etiope, Giuseppe; Gasperini, Luca; Bortoluzzi, Giovanni; Henry, Pierre; Grall, Celine; Cagatay, M. Namik; Charlou, Jean-luc; Geli, Louis.
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00139/24982/23065.pdf

Sulfate-dependent anaerobic oxidation of methane at a highly dynamic bubbling site in the Eastern Sea of Marmara (Çinarcik Basin)
Provedor de dados: 5
Autores: Teichert, B. M. A.; Chevalier, N.; Gussone, N.; Bayon, Germain; Ponzevera, Emmanuel; Ruffine, Livio; Strauss, H.
During the MARSITECruise expedition in November 2014 on board the RV Pourquoi Pas?, multidisciplinary sampling was carried out with the ROV Victor 6000 in order to investigate biogeochemical processes taking place at cold seep environments in the Sea of Marmara. Pore water, bottom water, sediment and authigenic carbonate samples were collected from two short push cores (MRS-DV5-PC04 − 8 cm, MRS-DV5-PC01 − 12.5 cm) at an active methane bubbling site in the southeastern part of the Çinarcik Basin. Sulfate sulfur and oxygen isotope data as well as sulfide isotope data indicate that sulfate-dependent anaerobic oxidation of methane is the dominant process in the sediments. This is confirmed by archaeal lipids diagnostic for anaerobic methane oxidizers detected...
Tipo: Text
Palavras-chave: Sea of Marmara; Cinarcik Basin; Methane; Sulfate reduction; Anaerobic oxidation of methane; Authigenic carbonate; Lipid biomarker.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00413/52480/53267.pdf

Living (stained) deep-sea foraminifera from the Sea of Marmara: a preliminary study
Provedor de dados: 5
Autores: Fontanier, Christophe; Dissard, D.; Ruffine, Livio; Mamo, B.; Ponzevera, Emmanuel; Pelleter, Ewan; Baudin, F.; Roubi, Angelique; Cheron, Sandrine; Boissier, Audrey; Gayet, Nicolas; Bermell-fleury, S.; Pitel, M.; Guyader, Vivien; Lesongeur, Francoise; Savignac, F.
In this preliminary study, we investigate living (stained) foraminifera from the Sea of Marmara. We focus on the faunal composition and geochemical signatures (trace elements, carbon and oxygen stable isotopes) in foraminiferal tests at two deep-sea sites (329 and ~1240 m depth respectively). Documented by ROV observations and sampling, both study areas are heterogeneous (including bacterial mats and carbonate concretions), proximal to cold seeps and consist of dysoxic bottom water (O2&lt;20 µmol/L). The prevailing dysoxia at both study areas restricts foraminiferal diversity to very low values (S&lt;9, H’&lt;0.97). Stress-tolerant species Bolivina vadescens and Globobulimina affinis dominate living faunas at both sites. The highest foraminiferal standing...
Tipo: Text
Palavras-chave: Living (stained) benthic foraminifera; Sea of Marmara; Extreme ecosystems; Trace elements; Stable isotopes.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00416/52774/53646.pdf

Rare earth elements and neodymium isotopes in world river sediments revisited
Provedor de dados: 5
Autores: Bayon, Germain; Toucanne, Samuel; Skonieczny, Charlotte; Andre, L.; Bermell, Sylvain; Cheron, Sandrine; Dennielou, Bernard; Etoubleau, Joel; Freslon, Nicolas; Gauchery, T.; Germain, Yoan; Jorry, Stephan; Menot, G.; Monin, L.; Ponzevera, Emmanuel; Rouget, M. -l.; Tachikawa, K.; Barrat, Jean-alix.
Over the past decades, rare earth elements (REE) and their radioactive isotopes have received tremendous attention in sedimentary geochemistry, as tracers for the geological history of the continental crust and provenance studies. In this study, we report on elemental concentrations and neodymium (Nd) isotopic compositions for a large number of sediments collected near the mouth of rivers worldwide, including some of the world’s major rivers. Sediments were leached for removal of non-detrital components, and both clay and silt fractions were retained for separate geochemical analyses. Our aim was to re-examine, at the scale of a large systematic survey, whether or not REE and Nd isotopes could be fractionated during Earth surface processes.  Our results...
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00276/38733/37249.pdf

Assessment of the metal contamination evolution in the Loire estuary using Cu and Zn stable isotopes and geochemical data in sediments
Provedor de dados: 5
Autores: Ferreira Araujo, Daniel; Ponzevera, Emmanuel; Briant, Nicolas; Knoery, Joel; Sireau, Teddy; Mojtahid, Meryem; Metzger, Edouard; Brach-papa, Christophe.
In this work, a multi-elemental approach combining Cu and Zn stable isotopes is used to assess the metal contamination evolution in the Loire estuary bulk sediments. Elemental geochemical data indicate an increase of metal concentrations from the beginning of the industrial period peaking in the 1990s, followed by an attenuation of metal contamination inputs to the estuary. Zinc isotope compositions suggest a binary mixing process between Zn derived from terrigenous material and multi-urban anthropogenic sources. Copper isotope systematics indicate a single natural dominant source represented by weathered silicate particles from soils and rocks. This work demonstrates the applicability of Zn isotopes to identify anthropogenic Zn sources in coastal systems,...
Tipo: Text
Palavras-chave: Coastal pollution; Coastal biogeochemistry; Geochemical tracers; Metal isotopes; Trace metal; Anthropogenic contamination.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00490/60188/67760.pdf

The Amsterdam-St. Paul Plateau: A complex hot spot/DUPAL-flavored MORB interaction
Provedor de dados: 5
Autores: Janin, M.; Hemond, Christophe; Maia, Marcia; Nonnotte, Philippe; Ponzevera, Emmanuel; Johnson, K. T. M.
The Amsterdam-St Paul (ASP) oceanic plateau results from the interaction between the ASP hot spot and the Southeast Indian ridge. A volcanic chain, named the Chain of the Dead Poets (CDP), lies to its northward tip and is related to the hot spot intraplate activity. The ASP plateau and CDP study reveals that ASP plume composition is inherited from oceanic crust and pelagic sediments recycled in the mantle through a 1.5 Ga subduction process. The ASP plateau lavas have a composition (major and trace elements and Sr-Nd-Pb-Hf isotopes) reflecting the interaction between ASP plume and the Indian MORB mantle, including some clear DUPAL input. The Indian upper mantle below ASP plateau is heterogeneous and made of a depleted mantle with lower continental crust...
Tipo: Text
Palavras-chave: DUPAL anomaly; Indian Ocean; Sr-Nd-Pb-Hf isotopes; Ridge-hot spot interaction.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00102/21368/19008.pdf

Intensifying Weathering and Land Use in Iron Age Central Africa
Provedor de dados: 5
Autores: Bayon, Germain; Dennielou, Bernard; Etoubleau, Joel; Ponzevera, Emmanuel; Toucanne, Samuel; Bermell, Sylvain.
About 3000 years ago, a major vegetation change occurred in Central Africa, when rainforest trees were abruptly replaced by savannas. The consensus is that the forest disturbance was caused by climate change. We show here that chemical weathering in Central Africa, reconstructed from geochemical analyses of a marine sediment core, intensified abruptly at the same period, departing significantly from the long-term weathering fluctuations related to the Late Quaternary climate. Evidence that this weathering event was also contemporaneous with the migration of Bantu-speaking farmers across Central Africa suggests that human land-use intensification at that time already had a significant impact on the rainforest.
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00069/18031/15574.pdf

Abrupt drainage cycles of the Fennoscandian Ice Sheet
Provedor de dados: 5
Autores: Soulet, Guillaume; Menot, Guillemette; Bayon, Germain; Rostek, Frauke; Ponzevera, Emmanuel; Toucanne, Samuel; Lericolais, Gilles; Bard, Edouard.
Continental ice sheets are a key component of the Earth’s climate system, but their internal dynamics need to be further studied. Since the last deglaciation, the northern Eurasian Fennoscandian Ice Sheet (FIS) has been connected to the Black Sea (BS) watershed, making this basin a suitable location to investigate former ice-sheet dynamics. Here, from a core retrieved in the BS, we combine the use of neodymium isotopes, high-resolution elemental analysis, and biomarkers to trace changes in sediment provenance and river runoff. We reveal cyclic releases of meltwater originating from Lake Disna, a proglacial lake linked to the FIS during Heinrich Stadial 1. Regional interactions within the climate–lake–FIS system, linked to changes in the availability of...
Tipo: Text
Palavras-chave: Ice dynamics; Meltwater routing; European hydrographic network.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00134/24489/22516.pdf

Multidisciplinary investigation on cold seeps with vigorous gas emissions in the Sea of Marmara (MarsiteCruise): Strategy for site detection and sampling and first scientific outcome
Provedor de dados: 5
Autores: Ruffine, Livio; Ondreas, Helene; Blanc-valleron, Marie-madeleine; Teichert, Barbara M. A.; Scalabrin, Carla; Rinnert, Emmanuel; Birot, Dominique; Croguennec, Claire; Ponzevera, Emmanuel; Pierre, Catherine; Donval, Jean-pierre; Alix, Anne-sophie; Germain, Yoan; Bignon, Laurent; Etoubleau, Joel; Caprais, Jean-claude; Knoery, Joel; Lesongeur, Francoise; Thomas, Bastien; Roubi, Angelique; Legoix, Ludovic Nicolas; Burnard, Pete; Chevalier, Nicolas; Lu, Hailong; Dupre, Stephanie; Fontanier, Christophe; Dissard, Delphine; Olgun, Nazli; Yang, Hailin; Strauss, Harald; Ozaksoy, Volkan; Perchoc, Jonathan; Podeur, Christian; Tarditi, Corinne; Ozbeki, Eyyup; Guyader, Vivien; Marty, Bernard; Madre, David G; Pitel-roudaut, Mathilde; Grall, Celine; Embriaco, Davide; Polonia, Mina; Gasperini, Lucas; Cagatay, M. Namik; Henry, Pierre; Geli, Louis.
MarsiteCruise was undertaken in October/November 2014 in the Sea of Marmara to gain detailed insight into the fate of fluids migrating within the sedimentary column and partially released into the water column. The overall objective of the project was to achieve a more global understanding of cold-seep dynamics in the context of a major active strike-slip fault. Five remotely operated vehicle (ROV) dives were performed at selected areas along the North Anatolian Fault and inherited faults. To efficiently detect, select and sample the gas seeps, we applied an original procedure. It combines sequentially (1) the acquisition of ship-borne multibeam acoustic data from the water column prior to each dive to detect gas emission sites and to design the tracks of...
Tipo: Text
Palavras-chave: Acoustic survey; Authigenic carbonates; Biogeochemistry; Chemical analyses; Cold seeps; Dissolved major elements; Fluid seepage; Geology; In situ Raman analysis; Methane; ROV dives.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00433/54434/55783.pdf

Rock-type control of Ni, Cr, and Co phytoavailability in ultramafic soils
Provedor de dados: 5
Autores: Pedziwiatr, Artur; Kierczak, Jakub; Waroszewski, Jaroslaw; Ratie, Gildas; Quantin, Cecile; Ponzevera, Emmanuel.
Background and aims Ultramafic soils constitute an extreme environment for plants because of specific physico-chemical properties and the presence of Ni, Cr, and Co. We hypothesized that type of ultramafic parent rock depending on their origin affects the composition of soils and plants. Therefore, phytoavailability of metals would be higher in soil derived from serpentinized peridotite compared to serpentinite because of differences in susceptibility of minerals to weathering. Results Based on DTPA-CaCl2 extractions, we noted that soil derived from the serpentinized peridotite is characterized by a higher phytoavailability of Ni compared to soil derived from the serpentinite. On the contrary, plant species growing on soil derived from the serpentinite...
Tipo: Text
Palavras-chave: Peridotite; Serpentinite; Excluders; Ni isotopes; Ca/mg ratio.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00414/52537/53344.pdf

In situ Lithium and Boron isotope determinations in mica, pyroxene, and serpentine by LA-MC-ICP-MS
Provedor de dados: 5
Autores: Marti, Celine; Ponzevera, Emmanuel; Harlow, George.
Boron and Li are light, incompatible elements that preferentially partition into the liquid phase, whether melt or aqueous fluid, and thus are useful for tracking fluid-related processes in rocks. Most of the Li isotopic data presently available on subduction-related rocks are from whole-rock analyses; and the B isotopic analyses of subduction material have been carried out either on whole-rocks or in-situ on an accessory phase, such as tourmaline. The new method presented here couples an ESI New Wave UP-193-FX ArF* (193 nm) excimer laser-ablation microscope with a Neptune Plus (Thermo Scientific) MC-ICP-MS aiming to measure both Li and B isotopes in situ with good spatial resolution (metamorphic minerals are commonly chemically zoned, and whole-rock...
Tipo: Text
Palavras-chave: Boron isotopes; Lithium isotopes; LA-MC-ICP-MS; Subduction zone related silicates.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00274/38533/37050.pdf

Evidence for intense REE scavenging at cold seeps from the Niger Delta margin
Provedor de dados: 5
Autores: Bayon, Germain; Birot, Dominique; Ruffine, Livio; Caprais, Jean-claude; Ponzevera, Emmanuel; Bollinger, C.; Donval, Jean-pierre; Charlou, Jean-luc; Voisset, Michel; Grimaud, S.
For many trace elements, continental margins are the location of intense exchange processes between sediment and seawater, which control their distribution in the water column, but have yet to be fully understood. In this study, we have investigated the impact of fluid seepage at cold seeps on the marine cycle of neodymium. We determined dissolved and total dissolvable (TD) concentrations for REE and well-established tracers of fluid seepage (CH4, TDFe, TDMn), and Nd isotopic compositions in seawater samples collected above cold seeps and a reference site (i.e. away from any fluid venting area) from the Niger Delta margin. We also analyzed cold seep authigenic phases and various core-top sediment fractions (pore water, detrital component, easily leachable...
Tipo: Text
Palavras-chave: Rare earth elements; Neodymium isotopes; Seawater; Cold seeps; Fe-Mn oxyhydroxides; Benthic fluxes.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00066/17754/15571.pdf