Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Abiotic pyrite formation produces a large Fe isotope fractionation
AU - Guilbaud, Romain
AU - Butler, Ian B.
AU - Ellam, Rob M.
PY - 2011/6/24
Y1 - 2011/6/24
N2 - The iron isotope composition of sedimentary pyrite has been proposed as a potential proxy to trace microbial metabolism and the redox evolution of the oceans. We demonstrate that Fe isotope fractionation accompanies abiotic pyrite formation in the absence of Fe(II) redox change. Combined fractionation factors between Fe(II) aq, mackinawite, and pyrite permit the generation of pyrite with Fe isotope signatures that nearly encapsulate the full range of sedimentary δ 56Fe pyrite recorded in Archean to modern sediments. We propose that Archean negative Fe isotope excursions reflect partial Fe(II) aq utilization during abiotic pyrite formation rather than microbial dissimilatory Fe(III) reduction. Late Proterozoic to modern sediments may reflect greater Fe(II) aq utilization and variations in source composition.
AB - The iron isotope composition of sedimentary pyrite has been proposed as a potential proxy to trace microbial metabolism and the redox evolution of the oceans. We demonstrate that Fe isotope fractionation accompanies abiotic pyrite formation in the absence of Fe(II) redox change. Combined fractionation factors between Fe(II) aq, mackinawite, and pyrite permit the generation of pyrite with Fe isotope signatures that nearly encapsulate the full range of sedimentary δ 56Fe pyrite recorded in Archean to modern sediments. We propose that Archean negative Fe isotope excursions reflect partial Fe(II) aq utilization during abiotic pyrite formation rather than microbial dissimilatory Fe(III) reduction. Late Proterozoic to modern sediments may reflect greater Fe(II) aq utilization and variations in source composition.
U2 - 10.1126/science.1202924
DO - 10.1126/science.1202924
M3 - Journal article
C2 - 21700871
AN - SCOPUS:79959513214
VL - 332
SP - 1548
EP - 1551
JO - Science
JF - Science
SN - 0036-8075
IS - 6037
ER -