Publication Abstracts

Liu et al. 2019

Liu, P., C.E. Harman, J.F. Kasting, Y. Hu, and J. Wang, 2019: Can organic haze and O2 plumes explain patterns of sulfur mass-independent fractionation during the Archean? Earth Planet. Sci. Lett., 526, 115767, doi:10.1016/j.epsl.2019.115767.

The existence of mass-independently fractionated sulfur in Archean rocks is almost universally accepted as evidence for low atmospheric O2 and O3 concentrations at that time. But the detailed patterns of the Δ33S values and of the ratios Δ33S/δ34S and Δ36S/Δ33S remain to be explained, and the mechanism for producing the mass-independent fractionation remains controversial. Here, we explore the hypothesis that the relatively low Δ33S values seen during the Mid-Archean, 2.7-3.5 Ga, were caused by the presence of organic haze produced from photolysis of methane. This haze helped shield SO2 from photolysis, while at the same time providing surfaces on which unfractionated short-chain sulfur species could condense. The evolution of oxygenic photosynthesis, and the concomitant disappearance of organic haze towards the end of the Archean allowed more negatively fractionated S4 and S8 to form, thereby generating large positive fractionations in other sulfur species, including sulfate and H2S. Reduction of this sulfate to H2S by bacteria, followed by incorporation of H2S into pyrite, produced the large positive Δ33S values observed in the Neoarchean rock record, 2.5-2.7 Ga.

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BibTeX Citation

@article{li02110i,
  author={Liu, P. and Harman, C. E. and Kasting, J. F. and Hu, Y. and Wang, J.},
  title={Can organic haze and O2 plumes explain patterns of sulfur mass-independent fractionation during the Archean?},
  year={2019},
  journal={Earth Planet. Sci. Lett.},
  volume={526},
  pages={115767},
  doi={10.1016/j.epsl.2019.115767},
}

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RIS Citation

TY  - JOUR
ID  - li02110i
AU  - Liu, P.
AU  - Harman, C. E.
AU  - Kasting, J. F.
AU  - Hu, Y.
AU  - Wang, J.
PY  - 2019
TI  - Can organic haze and O2 plumes explain patterns of sulfur mass-independent fractionation during the Archean?
JA  - Earth Planet. Sci. Lett.
VL  - 526
SP  - 115767
DO  - 10.1016/j.epsl.2019.115767
ER  -

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