Blar i forfatter "Wirth, Richard"

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    • Authigenesis of biomorphic apatite particles from Benguela upwelling zone sediments off Namibia: The role of organic matter in sedimentary apatite nucleation and growth 

      Mänd, Kaarel; Kirsimäe, Kalle; Lepland, Aivo; Crosby, Chris H.; Bailey, Jake V.; Konhauser, Kurt O.; Wirth, Richard; Schreiber, Anja; Lumiste, Kaarel (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-30)
      Sedimentary phosphorites comprise a major phosphorus (P) ore, yet their formation remains poorly understood. Extant polyphosphate‐metabolizing bacterial communities are known to act as bacterial phosphate‐pumps, leading to episodically high dissolved phosphate concentrations in pore waters of organic‐rich sediment. These conditions can promote the precipitation of amorphous precursor phases that are ...

    • Putative fossils of chemotrophic microbes preserved in seep carbonates from Vestnesa Ridge, off northwest Svalbard, Norway 

      Himmler, Tobias; Cremiere, Antoine; Birgel, Daniel; Wirth, Richard; Orphan, Victoria J.; Kirsimae, Kalle; Knies, Jochen; Peckmann, Jörn; Lepland, Aivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-20)
      The microbial key players at methane seeps are methanotrophic archaea and sulfate-reducing bacteria. They form spherical aggregates and jointly mediate the sulfate-dependent anaerobic oxidation of methane (SD–AOM: CH4 + SO42– → HCO3– + HS– + H2O), thereby inducing the precipitation of authigenic seep carbonates. While seep carbonates constitute valuable archives for molecular fossils of SD–AOM-mediating ...