Consulta: subjectFacets:"Fe oxides"
Registros recuperados: 2
Data/hora: 09/06/2024 11:40:02

Iron oxide deposits associated with the ectosymbiotic bacteria in the hydrothermal vent shrimp Rimicaris exoculata
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Corbari, L; Cambon-bonavita, Marie-anne; Long, G; Grandjean, F; Zbinden, M; Gaill, F; Compere, P.
The Rimicaris exoculata shrimp is considered as a primary consumer that dominates the fauna of most Mid-Atlantic Ridge ( MAR) hydrothermal ecosystems. These shrimps harbour in their gill chambers an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the mineral concretions associated with these bacteria have been investigated by using LM, ESEM, TEM STEM and EDX microanalyses. The nature of the iron oxides in shrimps obtained from the Rainbow vent field has also been determined by Mossbauer spectroscopy. This multidisciplinary approach has revealed that the three layers of mineral crust in the Rimicaris exoculata shrimps consist of large concretions formed by...
Tipo: Text
Palavras-chave: Mid atlantic ridge; Deep sea; Microbial communities; Oxidizing bacteria; Trophic ecology; Ferrous ions; Fe oxides; Ferrihydrite; Biomineralization; Minerals.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4702.pdf

A First Look at Dissolved Ge Isotopes in Marine Sediments
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Baronas, J. Jotautas; Hammond, Douglas E.; Rouxel, Olivier; Monteverde, Danielle R.
The removal of chemical species from seawater during the precipitation of authigenic minerals is difficult to constrain but may play a major role in the global biogeochemical cycles of some elements, including silicon (Si) and germanium (Ge). Here, we present Ge/Si, δ74Ge, and supporting chemical data of pore waters and core incubations at three continental margin sites in California and the Gulf of Mexico. We used these data to partition Ge release and uptake by the various allogenic (delivered via sedimentation) and authigenic (formed in situ) phases in these sediments. About half of the pore water Ge (δ74Gepw = 1.3–2.4‰) is supplied by biogenic silica dissolution (δ74Ge ~ 3‰), with the other half contributed by lithogenic particulates (δ74Ge ~ 0.6‰)....
Tipo: Text
Palavras-chave: Germanium; Biogenic silica; Authigenesis; Fe oxides; Isotope fractionation; Continental margin.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00504/61556/65466.pdf