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| Himmler, Tobias; Birgel, Daniel; Bayon, Germain; Pape, Thomas; Ge, Lu; Bohrmann, Gerhard; Peckmann, Joern. |
| Authigenic carbonate deposits have been sampled with the remotely operated vehicle ‘MARUM-QUEST 4000 m’ from five methane seeps between 731 and 1823 m water depth along the convergent Makran continental margin, offshore Pakistan (northern Arabian Sea). Two seeps on the upper slope are located within the oxygen minimum zone (OMZ; ca. 100 to 1100 m water depth), the other sites are situated in oxygenated water below the OMZ (below 1100 m water depth). The carbonate deposits vary with regard to their spatial extent, sedimentary fabrics, and associated seep fauna: Within the OMZ, carbonates are spatially restricted and associated with microbial mats, whereas in the oxygenated zone below the OMZ extensive carbonate crusts are exposed on the seafloor with... |
| Tipo: Text |
Palavras-chave: Anaerobic oxidation of methane Authigenic carbonates Cold-seep carbonates; Makran subduction zone Oxygen minimum zone Methane Lipid biomarkers. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00280/39120/37673.pdf |
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| Himmler, Tobias; Bayon, Germain; Wangner, David; Enzmann, Frieder; Peckmann, Joern; Bohrmann, Gerhard. |
| Authigenic carbonate build-ups develop at seafloor methane-seeps, where microbially mediated sulphate-dependent anaerobic oxidation of methane facilitates carbonate precipitation. Despite being valuable recorders of past methane seepage events, their role as archives of atmospheric processes has not been examined. Here we show that cyclic sedimentation pulses related to the Indian monsoon in concert with authigenic precipitation of methane-derived aragonite gave rise to a well-laminated carbonate build-up within the oxygen minimum zone off Pakistan (northern Arabian Sea). U–Th dating indicates that the build-up grew during past ~1,130 years, creating an exceptional high-resolution archive of the Indian monsoon system. Monsoon-controlled formation of... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00358/46965/46880.pdf |
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