冷湧水炭酸塩岩中の嫌気的メタン酸化を示すバイオマーカー  [in Japanese] Biomarker compositions for anaerobic methane oxidation in cold-seep carbonates  [in Japanese]

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Author(s)

    • 荻原 成騎 OGIHARA Shigenori
    • 東京大学大学院理学系研究科地球惑星科学専攻 Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo

Abstract

The biomarkers and their specific carbon isotopic compositions (δ<sup>13</sup>C) have been analyzed in Cretaceous carbonate rocks collected from four areas in Hokkaido, Japan. Anaerobic oxidation of methane (AOM) might occur in Tappu-Kanajirizawa and Teshionakagawa-Abeshinaigawa carbonate rocks, which have found to be related to cold-seep biological fossil communities. The biomarker distributions and their δ<sup>13</sup>C values showed that these carbonates were presumably linked to Archaea and bacteria associated with AOM in these cold-seep environments. These carbonate samples contained the "tail to tail" linked isoprenoid hydrocarbons, crocetane (2, 6, 11, 15-tetramethylhexadecane), PME (2, 6, 10, 15, 19-pentamethyleicosane), and their unsaturated derivatives. Squalane (2, 6, 10, 15, 19, 23-hexamethyltetracosane), C<sub>40</sub> acyclic and cyclic isoprenoid hydrocarbons were also detected. The occurrence of these compounds indicates that Archaea clearly play an important role during carbonate precipitation in the cold-seep environments. Archeal biomarkers were depleted in <sup>13</sup>C, indicating that archaeal isoprenoids were biosynthesized from isotopically depleted carbon such as that derived from methane. In addition to the archaeal markers, the isotopically <sup>13</sup>C-depleted <i>iso</i> -and <i>anteiso</i>-alkanes, which were most likely derived from sulfate-reducing bacteria, were identified. These results support the model that the sulfate-reducing bacteria might be closely linked to Archaea responsible for the AOM, although these organisms were generally competitive. The Manji-Shikorozawa and Yubari-Utagoezawa carbonates, which were lacking the cold-seep fossil biological communities, showed similar biomarker distribution. Biomarker analyses indicated these carbonates could have potential as cold-seep carbonate, and biomarker is possibly a useful indicator of cold-seep carbonate.

Journal

  • Chikyukagaku

    Chikyukagaku 38(2), 45-55, 2004

    The Geochemical Society of Japan

References:  35

Cited by:  3

Codes

  • NII Article ID (NAID)
    110008680067
  • NII NACSIS-CAT ID (NCID)
    AN00141280
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    0386-4073
  • NDL Article ID
    6987348
  • NDL Source Classification
    ZM41(科学技術--地球科学)
  • NDL Call No.
    Z15-645
  • Data Source
    CJP  CJPref  NDL  NII-ELS  J-STAGE 
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