|
|
|
|
|
| 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 |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
|
