Comment on "Abiotic pyrite formation produces a large Fe isotope fractionation".
Guilbaud et al. (Reports, 24 June 2011, p. 1548) suggest that the geologic record of Fe isotope fractionation can be explained by abiological precipitation of pyrite. We argue that a detailed understanding of the depositional setting, mineralogy, and geologic history of Precambrian sedimentary rocks indicates that the Fe isotope record dominantly reflects biological fractionations and Fe redox processes.
Department of Geoscience, University of Wisconsin, Madison, WI 53706, USA. aczaja@geology.wisc.edu
Andrew D
AD
Czaja
Clark M
CM
Johnson
Kosei E
KE
Yamaguchi
Brian L
BL
Beard
D007501:Iron / Q000737:chemistry*; D007503:Iron Isotopes / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
D007503:Iron Isotopes; D013440:Sulfides; D007501:Iron