TY - JOUR
T1 - Formation of iron sulfide nodules during anaerobic oxidation of methane
AU - van Dongen, Bart E.
AU - Roberts, Andrew P.
AU - Schouten, Stefan
AU - Jiang, Wei Teh
AU - Florindo, Fabio
AU - Pancost, Richard D.
N1 - Funding Information:
We thank Dr. Ian D. Bull, Dr Rob Berstan, Martijn Woltering and Dr. Ellen Hopmans for technical assistance, NERC for funding the Bristol node of the Life Sciences Mass Spectrometry Facility (Agreement No. F14/6/13/01; http://www.chm.bris.ac.uk/lsmsf/index.html ) and for financial support to B. van Dongen (grant NER/A/S/2001/01213), Luke Handley for preparing the samples for GDGT analysis and Dr. David Burdige (Associate Editor) and Dr. D. Valentine and two anonymous reviewers for comments that improved the manuscript.
PY - 2007/11/1
Y1 - 2007/11/1
N2 - The biomarker compositions of iron sulfide nodules (ISNs; upper Pliocene Valle Ricca section near Rome, Italy) that contain the ferrimagnetic mineral greigite (Fe3S4) were examined. In addition to the presence of specific terrestrial and marine biomarkers, consistent with formation in coastal marine sediments, these ISNs contain compounds thought to originate from sulfate reducing bacteria (SRB). These compounds include a variety of low-molecular-weight and branched alkanols and several non-isoprenoidal dialkyl glycerol diethers (DGDs). In addition, archaeal biomarkers, including archaeol, macrocyclic isoprenoidal DGDs and isoprenoidal glycerol dialkyl glycerol tetraethers are also present. Both SRB and archaeal lipid δ13C values are depleted in 13C (δ13C values are typically less than -50‰), which suggests that the SRB and archaea consumed 13C depleted methane. These biomarker and isotopic signatures are similar to those found in cold seeps and marine sediments where anaerobic oxidation of methane (AOM) occurs with sulfate serving as the terminal electron acceptor. Association of AOM with formation of greigite-containing ISNs could provide an explanation for documented remagnetization of the Valle Ricca sediments. Upward migration of methane, subsequent AOM and associated authigenic greigite formation are widespread processes in the geological record that have considerable potential to compromise paleomagnetic records.
AB - The biomarker compositions of iron sulfide nodules (ISNs; upper Pliocene Valle Ricca section near Rome, Italy) that contain the ferrimagnetic mineral greigite (Fe3S4) were examined. In addition to the presence of specific terrestrial and marine biomarkers, consistent with formation in coastal marine sediments, these ISNs contain compounds thought to originate from sulfate reducing bacteria (SRB). These compounds include a variety of low-molecular-weight and branched alkanols and several non-isoprenoidal dialkyl glycerol diethers (DGDs). In addition, archaeal biomarkers, including archaeol, macrocyclic isoprenoidal DGDs and isoprenoidal glycerol dialkyl glycerol tetraethers are also present. Both SRB and archaeal lipid δ13C values are depleted in 13C (δ13C values are typically less than -50‰), which suggests that the SRB and archaea consumed 13C depleted methane. These biomarker and isotopic signatures are similar to those found in cold seeps and marine sediments where anaerobic oxidation of methane (AOM) occurs with sulfate serving as the terminal electron acceptor. Association of AOM with formation of greigite-containing ISNs could provide an explanation for documented remagnetization of the Valle Ricca sediments. Upward migration of methane, subsequent AOM and associated authigenic greigite formation are widespread processes in the geological record that have considerable potential to compromise paleomagnetic records.
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U2 - 10.1016/j.gca.2007.08.019
DO - 10.1016/j.gca.2007.08.019
M3 - Article
AN - SCOPUS:35549006862
SN - 0016-7037
VL - 71
SP - 5155
EP - 5167
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
IS - 21
ER -
