Consulta: creatorFacets:"Feng, Dong"
Registros recuperados: 4
Data/hora: 03/06/2024 02:33:48

Using chemical compositions of sediments to constrain methane seepage dynamics: A case study from Haima cold seeps of the South China Sea
Provedor de dados: 5
Autores: Wang, Xudong; Li, Niu; Feng, Dong; Hu, Yu; Bayon, Germain; Liang, Qianyong; Tong, Hongpeng; Gong, Shanggui; Tao, Jun; Chen, Duofu.
Cold seeps frequently occur at the seafloor along continental margins. The dominant biogeochemical processes at cold seeps are the combined anaerobic oxidation of methane and sulfate reduction, which can significantly impact the global carbon and sulfur cycles. The circulation of methane-rich fluids at margins is highly variable in time and space, and assessing past seepage activity requires the use of specific geochemical markers. In this study, we report multiple sedimentary proxy records for three piston gravity cores (QDN-14A, QDN-14B, and QDN-31) from the Haima seep of the South China Sea (SCS). By combining total organic carbon (TOC), total inorganic carbon (TIC), total nitrogen (TN), total sulfur (TS), acid insoluble carbon and sulfur isotope...
Tipo: Text
Palavras-chave: Cold seep; Anaerobic oxidation of methane; Carbon and sulfur isotopes; South China Sea.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00465/57662/59858.pdf

Microbial utilization of rare earth elements at cold seeps related to aerobic methane oxidation
Provedor de dados: 5
Autores: Bayon, Germain; Lemaitre, Nolwenn; Barrat, Jean-alix; Wang, Xudong; Feng, Dong; Duperron, Sebastien.
A major breakthrough in the field of rare earth element (REE) geochemistry has been the recent discovery of their utility to microbial life, as essential metalloenzymes catalyzing the oxidation of methanol to formaldehyde. Lanthanide-dependent bacteria are thought to be ubiquitous in marine and terrestrial environments, but direct field evidence of preferential microbial utilization of REE in natural systems is still lacking. In this study, we report on the REE and trace element composition of the tube of a siboglinid worm collected at a methane seep in the Gulf of Guinea; a tube-dwelling annelid that thrives in deep-sea chemosynthetic ecosystems. High-resolution trace element profiles along the chitin tube indicate marked enrichments of lanthanum (La) and...
Tipo: Text
Palavras-chave: Tubeworms; Siboglinidae; Lanthanide-dependent bacteria; Metalloenzymes; Methylotrophy; Regab; Authigenic carbonates; Archaean.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00643/75496/76352.pdf

Trace element systematics in cold seep carbonates and associated lipid compounds
Provedor de dados: 5
Autores: Wang, Xudong; Bayon, Germain; Kim, Jung-hyun; Lee, Dong-hun; Kim, Dahae; Guéguen, Bleuenn; Rouget, Marie-laure; Barrat, Jean-alix; Toffin, Laurent; Feng, Dong.
Seeping of methane-rich fluids at submarine cold seeps drives intense microbial activity and precipitation of authigenic carbonates. Some trace elements play an important role in the biogeochemical processes operating at cold seeps, especially as specific enzymatic co-factors related to methanogenesis and the anaerobic oxidation of methane (AOM). However, it is unclear whether microbial trace metal utilization can be traced by the geochemical composition of seep carbonates. In this study, we analyzed a series of authigenic carbonate samples recovered from various seep settings worldwide and report for the first time trace element concentrations for total lipid fractions, combined with biomarker analyses and determination of elemental abundances in...
Tipo: Text
Palavras-chave: Seep carbonate; Lipid compounds; Trace elements; Tungsten; Nickel; Cobalt; Molybdenum.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00511/62311/66562.pdf

Gas hydrate dissociation during sea‐level highstand inferred from U/Th dating of seep carbonate from the South China Sea
Provedor de dados: 5
Autores: Chen, Fang; Wang, Xudong; Li, Niu; Cao, Jun; Bayon, Germain; Peckmann, Jörn; Hu, Yu; Gong, Shanggui; Cheng, Hai; Edwards, R. Lawrence; Ning, Youfeng; Jin, Meng; Huang, Huiwen; Wu, Cong; Sun, Yuedong; Chen, Hong; Zhou, Yang; Chen, Duofu; Feng, Dong.
Gas hydrates represent a huge reservoir of methane in marine sediments, prone to dissociation in response to environmental changes. There is consensus that past events of gas hydrate dissociation in the marine environment mainly occurred during periods of low sea‐level. Here, we report geochemical data for two meter‐thick layers of seep carbonate collected from a hydrate‐bearing drill core from ~800 m water depth in the northern South China Sea. The aragonite‐rich carbonates reveal positive δ18O values, confirming a genetic link with gas hydrate dissociation. Uranium‐thorium dating of seep carbonates indicates that gas hydrates at the study site dissociated between 133,300 and 112,700 yr BP, hence coinciding with the Last Interglacial (MIS 5e) sea level...
Tipo: Text
Palavras-chave: Methane seep gas hydrate seep carbonate.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00593/70555/68725.pdf