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Registros recuperados: 8
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Controls on Holocene denudation rates in mountainous environments under Mediterranean climate ArchiMer
Molliex, S.; Jouet, Gwenael; Freslon, Nicolas; Bourles, D. L.; Authemayou, C.; Moreau, Julien; Rabineau, Marina.
The Mediterranean domain is characterized by a specific climate resulting from the close interplay between atmospheric and marine processes and strongly differentiated regional topographies. Corsica Island, a mountainous area located in the western part of the Mediterranean Sea is particularly suitable to quantify regional denudation rates in the framework of a source-to-sink approach. Indeed, fluvial sedimentation in East-Corsica margin is almost exclusively limited to its alluvial plain and offshore domain and its basement is mainly constituted of quartz-rich crystalline rocks allowing cosmogenic nuclide Be-10 measurements. In this paper, Holocene denudation rates of catchments from the eastern part of the island of Corsica are quantified relying on in...
Tipo: Text Palavras-chave: Be-10-derived denudation rates; Schmidt Hammer; Quaternary; Quantitative geomorphology; Weathering.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00380/49082/49655.pdf
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Determination of rare earth elements and other trace elements (Y, Mn, Co, Cr) in seawater using Tm addition and Mg(OH)(2) co-precipitation ArchiMer
Freslon, Nicolas; Bayon, Germain; Birot, Dominique; Bollinger, Claire; Barrat, Jean-alix.
This paper reports on a novel procedure for determining trace element abundances (REE and Y, Cr, Mn, Co) in seawater by inductively coupled plasma sector field mass spectrometry (ICP-SFMS). The procedure uses a combination of pre-concentration using co-precipitation onto magnesium hydroxides and addition of thulium spike. The validity of the method was assessed onto 25 ml volumes of certified reference materials (NASS- and CASS-4) and in house seawater standard. Procedural blanks were determined by applying the same procedure to aliquots of seawater previously depleted in trace elements by successive Mg(OH)(2) co-precipitations, yielding estimated contributions to the studied samples better than 1.1% for all elements, with the exception of Cr (<3.3%)...
Tipo: Text Palavras-chave: Trace elements; Rare earth elements (REE); Seawater; Mg(OH)(2) co-precipitation; ICP-MS; Thulium.
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00041/15220/15855.pdf
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Determination of trace elements in seawater by ICP-SFMS after Tm addition and co-precipitation ArchiMer
Freslon, Nicolas; Bayon, Germain; Birot, Dominique; Bollinger, C.; Barrat, J. A..
Tipo: Text
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00023/13411/10486.pdf
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Millennial-scale fluctuations of the European Ice Sheet at the end of the last glacial, and their potential impact on global climate ArchiMer
Toucanne, Samuel; Soulet, Guillaume; Freslon, Nicolas; Jacinto, Ricardo Silva; Dennielou, Bernard; Zaragosi, Sebastien; Eynaud, Frederique; Bourillet, Jean-francois; Bayon, Germain.
Reconstructing Northern Hemisphere ice-sheet oscillations and meltwater routing to the ocean is important to better understand the mechanisms behind abrupt climate changes. To date, research efforts have mainly focused on the North American (Laurentide) ice-sheets (LIS), leaving the potential role of the European Ice Sheet (EIS), and of the Scandinavian ice-sheet (SIS) in particular, largely unexplored. Using neodymium isotopes in detrital sediments deposited off the Channel River, we provide a continuous and well-dated record for the evolution of the EIS southern margin through the end of the last glacial period and during the deglaciation. Our results reveal that the evolution of EIS margins was accompanied with substantial ice recession (especially of...
Tipo: Text Palavras-chave: European ice-sheet; Channel River; Meltwater; Deglaciation; Neodymium; Termination.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00272/38346/36675.pdf
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Origin and significance of tourmalinites and tourmaline-bearing rocks of Menderes Massif, western Anatolia, Turkey ArchiMer
Yucel-ozturk, Yesim; Helvaci, Cahit; Palmer, Martin R.; Ersoy, E. Yalcin; Freslon, Nicolas.
In the western central portion of Anatolia lies the Menderes Massif – a large metamorphic crystalline complex made of Neoproterozoic to Precambrian basement rocks overlain by Palaeozoic to early Tertiary metasedimentary rocks, and with a multistage metamorphic evolution developed from the late Neo-Proterozoic to Eocene. We have undertaken a study of the petrology, geochemistry and boron isotope composition of these tourmaline occurrences aiming to constrain the processes responsible for the enrichment of boron and other fluid mobile elements in the Menderes Massif. The dispersed tourmaline has chemical and boron isotope compositions typical of a continental crust setting, but while some of the tourmalinites display similar signatures, others have heavier...
Tipo: Text Palavras-chave: Tourmalinites; Geochemistry; Boron isotope; Menderes Massif; Western Anatolia; Turkey.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00250/36121/34675.pdf
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Rare earth elements and neodymium isotopes in sedimentary organic matter ArchiMer
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
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Rare earth elements and neodymium isotopes in world river sediments revisited ArchiMer
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
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Trace element behaviour at cold seeps and the potential export of dissolved iron to the ocean ArchiMer
Lemaitre, Nolwenn; Bayon, Germain; Ondreas, Helene; Caprais, Jean-claude; Freslon, Nicolas; Bollinger, Claire; Rouget, Marie-laure; De Prunele, Alexis; Ruffine, Livio; Olu-le Roy, Karine; Sarthou, Geraldine.
Seawater samples were collected by submersible above methane seeps in the Gulf of Guinea (Regab and Baboon pockmarks) in order to investigate the behaviour of iron (Fe), manganese (Mn) and rare earth elements (REE) during fluid seepage. Our aim was to determine whether cold seeps may represent potential sources of dissolved chemical species to the ocean. Dissolved (<0.45 μm filtered samples) and total dissolvable (unfiltered samples) concentrations were determined over ∼50 m long vertical transects above the seafloor and at various discrete locations within the pockmarks. We show that substantial amounts of Fe and Mn are released into seawater during seepage of methane-rich fluids. Mn is exported almost quantitatively in the dissolved form (more than...
Tipo: Text Palavras-chave: Iron; Rare earth elements; Cold seeps; Seawater; Organic ligands; Iron-sulfide nanoparticles.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00211/32190/30704.pdf
Registros recuperados: 8
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