Consulta: creatorFacets:"Chaduteau, Carine"
Registros recuperados: 5
Data/hora: 05/06/2024 04:31:17

Archaeal communities associated with shallow to deep subseafloor sediments of the New Caledonia Basin
Provedor de dados: 5
Autores: Roussel, Erwan; Sauvadet, Anne-laure; Chaduteau, Carine; Fouquet, Yves; Charlou, Jean-luc; Prieur, Daniel; Cambon, Marie-anne.
P&gt;The distribution of the archaeal communities in deep subseafloor sediments [0-36 m below the seafloor (mbsf)] from the New Caledonia and Fairway Basins was investigated using DNA- and RNA-derived 16S rRNA clone libraries, functional genes and denaturing gradient gel electrophoresis (DGGE). A new method, Co-Migration DGGE (CM-DGGE), was developed to access selectively the active archaeal diversity. Prokaryotic cell abundances at the open-ocean sites were on average similar to 3.5 times lower than at a site under terrestrial influence. The sediment surface archaeal community (0-1.5 mbsf) was characterized by active Marine Group 1 (MG-1) Archaea that co-occurred with ammonia monooxygenase gene (amoA) sequences affiliated to a group of uncultured...
Tipo: Text
Palavras-chave: Marine subsurface sediments; Sea floor biosphere; Gradient gel electrophoresis; Microbial communities; Molecular diversity; Anaerobic oxidation; Sequence alignment; Phylogenetic trees; Extracellular DNA; Methane hydrate.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6801.pdf

Carbon isotope evidence for large methane emissions to the Proterozoic atmosphere
Provedor de dados: 5
Autores: Cadeau, Pierre; Jézéquel, Didier; Leboulanger, Christophe; Fouilland, Eric; Le Floc’h, Emilie; Chaduteau, Carine; Milesi, Vincent; Guélard, Julia; Sarazin, Gérard; Katz, Amandine; D’amore, Sophie; Bernard, Cecile; Ader, Magali.
The Proterozoic Era records two periods of abundant positive carbon isotope excursions (CIEs), conventionally interpreted as resulting from increased organic carbon burial and leading to Earth’s surface oxygenation. As strong spatial variations in the amplitude and duration of these excursions are uncovered, this interpretation is challenged. Here, by studying the carbon cycle in the Dziani Dzaha Lake, we propose that they could be due to regionally variable methane emissions to the atmosphere. This lake presents carbon isotope signatures deviated by ~  + 12‰ compared to the modern ocean and shares a unique combination of analogies with putative Proterozoic lakes, interior seas or restricted epireic seas. A simple box model of its Carbon cycle demonstrates...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00656/76784/77944.pdf

Archaeal Methane Cycling Communities Associated with Gassy Subsurface Sediments of Marennes-Oleron Bay (France)
Provedor de dados: 5
Autores: Roussel, Erwan; Sauvadet, Anne Laure; Allard, Jonathan; Chaduteau, Carine; Richard, Pierre; Cambon Bonavita, Marie-anne; Chaumillon, Eric.
In Marennes-Oleron Bay, a macro-tidal bay located on the French Atlantic coast, kilometer-scale acoustic turbidity reveals an accumulation of free gas in the sediment. Large concentrations of organic matter and rapid sedimentation rates provide ideal settings for biogenic methane cycling. We integrate seismic, sedimentologic, biogeochemical and molecular genetic approaches to determine whether microbial methane cycling is involved in this process. Here we show that the acoustic turbidity upper boundary matched with X-ray facies displaying fissures with the highest methane concentrations, demonstrating the existence of methane bubbles in the sediment. 16S rRNA and mcrA gene clone libraries were dominated by sequences affiliated to the three known ANME...
Tipo: Text
Palavras-chave: Sediment; Methane; McrA; 16S rRNA; Archaea.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6165.pdf

Helium transport in sediment pore fluids of the Congo-Angola margin
Provedor de dados: 5
Autores: Chaduteau, Carine; Jean-baptiste, Philippe; Fourre, Elise; Charlou, Jean-luc; Donval, Jean-pierre.
During the ZaiRov2 cruise of the ZaiAngo project (1998-2000) on the passive Congo-Angola margin, several gravity cores were analyzed for helium isotopic composition of sedimentary pore waters in two cold fluid seepage zones: the Astrid slide area and the Regab giant pockmark. Gas concentration and isotopic composition are presented along with thermal data in terms of the origin and circulation of fluids. Helium isotope data lie on a mixing line between bottom seawater and an almost pure radiogenic. Helium and temperature vertical profiles are well described by the classic diffusion-advection equation. On the basis of He profiles, we estimate the advection rate on the rim of the pockmark between 1.2 and 2.3 mm/a. The He flux derived for a pure diffusive...
Tipo: Text
Palavras-chave: Zaire Angola margin; Sediment; Regab; Pore fluids; Pockmark; Helium.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6112.pdf

Origine et circulation des fluides dans les sédiments des marges. Contribution de l'hélium et du méthane dans la compréhension des processus. Étude de 2 zones actives
Provedor de dados: 5
Autores: Chaduteau, Carine.
Fluid migration is a very important process in marine sediments on margins. Studying fluids is fundamental to constrain the energy potential of margins. Methane is the predominant gas in marine sediments, deriving primarily from the degradation of organic matter. However methane could be also generated through the serpentinization of mantle rocks underlying the sedimentary cover in some specific geodynamical settings. One way to test this hypothesis is to use helium isotopes, which are known to be powerful tracers of the fluid-mantle interaction. To this purpose, a new method has been developed for the sampling and the quantitative extraction of dissolved helium from sediment pore-waters. During the Zairov2 and Vicking cruises, samples were collected in...
Tipo: Text
Palavras-chave: Mantle; Serpentinization; Advection; Mud volcano; Pockmark; Methane; Helium; Fluid; Margin; Manteau; Serpentinisation; Advection; Volcan de boue; Pockmark; Méthane; Hélium; Fluide; Marge.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-3724.pdf