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| Titel |
Interpretation of multiple archaeal lipid biomarkers in deep sediments bearing gas hydrate in the East Sea |
| VerfasserIn |
Lee Dong-Hun, Jong-Gu Gal, Ji-Hoon Kim, Jang-Jun Bahk, Kyung-Hoon Shin |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250094607
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| Publikation (Nr.) |
 EGU/EGU2014-10028.pdf |
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| Zusammenfassung |
| We investigate the distributions and stable carbon isotope values of arhaeal lipid biomarkers
at seismically chimney and non-chimney sites (UBGH 2-3, UBGH 2-1_1) of gas hydrate
bearing deep core sediments during the second Ulleung Basin Gas Hydrate Drilling
Expedition (UBGH 2). The objective of this study was to identify and compare the metabolic
pathway of methane-related archaea between both sites. The increased concentration and
δ13C-depleted archaeol and sn-2-hydroxyarcheol at the Sulphate-Methane transition Zone
(SMTZ) of UBGH 2-1_1 could be predominantly methanotrophic activity indicating methane
consumption by Anaerobic Oxidation of Methane (AOM). The concentration of
methane-related specific biomarkers (PMI, crocetane, archaeol, sn-2-hydroxyarcheol) within
deep core sediment bearing gas hydrate of both sites is relatively higher than in other
sediment sections, showing lower Cl- concentration. The carbon stable isotopic data (–47.5
o –75.2oto –52.4) for archaeol, sn-2-hydroxyarcheol in the sediment sections (20mbsf,
93 - 100mbsf) at UBGH 2-1_1 reflect methane production via microbial carbon
dioxide reduction in deep core sediment. Archaeal lipid biomarker concentrations are
slightly different depending on upward methane diffusion or advection with the
seismic characteristics of both sites. Based on the archaeal lipid biomarker ratio
(sn-2-hydroxyarchaeol/archaeol) as a tool to demonstrate the different ANME communities,
our result suggest that the predominant occurrence of ANMEs is mediated by upward
migration of microbial methane. Consequently, geochemical signature of archaeal lipid
biomarkers in the East Sea of the western North Paci?c may be a potential indicator
reflected by upward transported-methane in methane cycle of deep core sediment.
In addition, the distribution of glycerol dialkyl glycerol tetraethers (GDGTs) is
discussed with archaeal lipid biomarkers in the gas hydrate bearing deep sediment. |
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