Stromatolites below the photic zone in the northern Arabian Sea formed by calcifying chemotrophic microbial mats

Autor(en)
Tobias Himmler, Daniel Smrzka, Jennifer Zwicker, Sabine Kasten, Russell Shapiro, Gerhard Bohrmann, Jörn Ludwig Peckmann
Abstrakt

Chemosynthesis increases alkalinity and facilitates stromatolite growth at methane seeps in 731 m water depth within the oxygen minimum zone (OMZ) in the northern Arabian Sea. Microbial fabrics, including mineralized filament bundles resembling the sulfideoxidizing bacterium Thioploca, mineralized extracellular polymeric substances, and fossilized rod-shaped and filamentous cells, all preserved in 13C-depleted authigenic carbonate, suggest that biofilm calcification resulted from nitrate-driven sulfide oxidation (ND-SO) and sulfate-driven anaerobic oxidation of methane (SD-AOM). Geochemical batch modeling reveals that the collective effects of ND-SO and SD-AOM increase alkalinity more than SD-AOM alone, explaining the preservation of sulfide-oxidizing bacteria in authigenic carbonate. These findings demonstrate the biogenicity of a conical stromatolite associated with OMZ methane seeps and confirm the fact that,
apart from photosynthesis-based metabolisms, chemosynthesis-based metabolisms can also account for stromatolite formation.

Organisation(en)
Institut für Geologie
Externe Organisation(en)
California State University, Chico, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Universität Bremen, Universität Hamburg
Journal
Geology
Band
46
Seiten
339-342
Anzahl der Seiten
4
ISSN
0091-7613
DOI
https://doi.org/10.1130/G39890.1
Publikationsdatum
02-2018
Peer-reviewed
Ja
ÖFOS 2012
105128 Geomikrobiologie, 105105 Geochemie, 105121 Sedimentologie
Schlagwörter
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/d2367b0f-2364-43ad-bc4d-1ab4e1915fe1