Consulta: subjectFacets:"Géochimie"
Registros recuperados: 4
Data/hora: 12/06/2024 02:08:32

Les nodules du pacifique central dans leur environnement géologique CAMPAGNES COPANO - 1979
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Pautot, Guy; Hoffert, Michel.
The cruises named COPANO have been undertaken during the summer 1979 on the R. V. Le Suroit of the CNEXO, as a part of an international research program I.C.I.M.E. The objective of this project was to study relatively small zones (a few km2) and to establish a relationship between characteristics of the manganese nodules and their environment. During the COPANO cruises, five zones have been studied: two in the northern Pacific, two in the southern Pacific and finally one in the equatorial Pacific. All the zones are centered on the longitude 134° Wand therefore their symmetry to the highly productive equatorial zone may be tested. As one of the results of the cruises is the relation between nodules and the bottom soil, established by sediment-sampling and a...
Tipo: Text
Palavras-chave: Géochimie; Cartographie; Geologie; Fonds marin; Environnement; Nodules; Geochemistry; Mapping; Structural geology; Environmental impact; Nodule.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/rapport-1144.pdf

Caractérisation physique et géochimique d'hydrates de gaz d'environnements géologiques différents. Apport des techniques de Diffraction X Synchrotron et de Spectroscopie Raman. Contribution à l'étude de leur origine, formation et stabilité sur les marges
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bourry, Christophe.
Clathrate hydrates are inclusion compounds consisting of an ice-like network of water cages surrounding occluded guest molecules. They occur beneath the oceans and in polar regions, where low temperature and high pressure conditions prevail. Natural gas hydrates, mainly composed of methane occur worldwide and may contain huge natural gas amount, but they can also play an important role in continental slope stability or climate change, due to the potentially enormous "greenhouse" feedback effect of methane. The knowledge of their occurrence in the natural environment, their physical, chemical or thermodynamical properties is essential to prevent geohazards, to anticipate their role in climate change or to develop technologies to take advantage of this...
Tipo: Text
Palavras-chave: X Ray synchrotron diffraction; Raman spectroscopy; Geochemistry; Gas hydrate; Eau interstitielle; Diffraction X synchrotron; Spectroscopie Raman; Géochimie; Hydrate de gaz.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-6236.pdf

Bilan des connaissances sur la Rive Droite de la Gironde
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Jouanneau, J. M.
Ce mémoire a pour objet de faire très succinctement le point des connaissances acquises à la fin de 1973 sur la rive droite de la Gironde. L'étude traite essentiellement des données de la géologie générale ; de la sédimentologie, de l'hydrologie et de la géochimie. Il y a été ajouté un chapitre sur l'écologie; cette discipline est en effet liée à plus d'un titre aux précédentes. C'est donc un bref résumé des données scientifiques rassemblées sur le milieu naturel.
Tipo: Text
Palavras-chave: Géologie; Morphologie; Estuaire; Gironde; Sédimentologie; Hydrologie; Géochimie.
Ano: 1973
URL: http://archimer.ifremer.fr/doc/00080/19155/16755.pdf

Origin of organic compounds in fluids from ultramafic-hosted hydrothermal vents of the Mid-Atlantic Ridge
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Konn, Cécile.
Natural gas, primarily methane (CH4), is produced in substantial amounts in ultramafic-hosted hydrothermal systems. These systems could also generate oil (heavier hydrocarbons) and the first building blocks of life (prebiotic molecules). In the presence of iron bearing minerals, serpentinisation reactions generate H2. Subsequently, CH4 could be synthesised by Fischer-Tropsch Type (FTT) reaction (4H2 + CO2 -&gt; CH4 + 2H2O) which is an abiotic process. This has lead to the idea of abiotic formation of larger organic molecules. Both thermodynamics and laboratory work support this idea, yet field data have been lacking. This study focuses on determining the organic content of fluids from ultramafic-hosted hydrothermal systems from the Mid-Atlantic Ridge (MAR)...
Tipo: Text
Palavras-chave: Origin of life; Geochemistry; Hydrothermal; Ultramafic; Organic compounds; Hydrocarbons; Serpentinisation; Origine de la vie; Géochimie; Systèmes hydrothermaux; Ultrabasique; Composés organiques; Hydrocarbures; Serpentinisation.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/these-6939.pdf