TY - JOUR
T1 - Sulfidization of 3.48 billion-year-old stromatolites of the Dresser Formation, Pilbara Craton
T2 - Constraints from in-situ sulfur isotope analysis of pyrite
AU - Baumgartner, Raphael J.
AU - Caruso, Stefano
AU - Fiorentini, Marco L.
AU - Van Kranendonk, Martin J.
AU - Martin, Laure
AU - Jeon, Heejin
AU - Pagès, Anais
AU - Wacey, David
N1 - Funding Information:
The authors acknowledge the facilities, and the scientific and technical assistance of the Microscopy Australia research facility at the Centre for Microscopy, Characterization and Analysis (UWA, Perth). The Mark Wainwright Analytical Centre is thanked for access to the Raman Spectroscopy laboratory. Part of this research was undertaken at the XFM beamline of the Australian Synchrotron (ANSTO). This study was supported by the Australian Research Council Centre of Excellence for Core to Crust Fluid Systems (www.ccfs.mq.edu.au). Additional support is from the University of New South Wales (Sydney), and the ARC Discovery Project 180103204. DW acknowledges an ARC Future Fellowship grant (FT140100321). We thank the reviewers Yanan Shen and Huan Cui for their thoughtful comments. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Funding Information:
The authors acknowledge the facilities, and the scientific and technical assistance of the Microscopy Australia research facility at the Centre for Microscopy, Characterization and Analysis (UWA, Perth). The Mark Wainwright Analytical Centre is thanked for access to the Raman Spectroscopy laboratory. Part of this research was undertaken at the XFM beamline of the Australian Synchrotron (ANSTO). This study was supported by the Australian Research Council Centre of Excellence for Core to Crust Fluid Systems ( www.ccfs.mq.edu.au ). Additional support is from the University of New South Wales (Sydney), and the ARC Discovery Project 180103204 . DW acknowledges an ARC Future Fellowship grant (FT140100321). We thank the reviewers Yanan Shen and Huan Cui for their thoughtful comments.
PY - 2020/4/5
Y1 - 2020/4/5
N2 - This study reports in–situ sulfur isotope analyses (32S, 33S, 34S and 36S) of pyrite in strongly sulfidized stromatolites from the ~3.48 billion–year–old Dresser Formation, Pilbara Craton, Australia. These data shed light on sulfur reservoirs and sulfide precipitation processes and provide clues for the contribution of sulfur–cycling microbes to sulfidization. Sulfur isotope signatures derived from mass dependent fractionation (MDF; monitored by δ34S) and mass independent fractionation (MIF; here Δ33S and Δ36S) of pyrite in stromatolites, and of microscopic pyrite within associated barite, allow for the identification of distinctive sulfur sources: i) magmatic–hydrothermal sulfide (H2S) with δ34S and Δ33S ~ 0%; ii) magmatic–hydrothermal sulfate (SO4 2 −) with a MDF signature (MDF–SO4 2 −; δ34S ~ 10‰ and Δ33S ~ 0‰; iii) photochemically–derived sulfate with a MIF signature (MIF–SO4; δ34S ~ −6‰ and Δ33S ~ −3.0‰); iv) photochemically–derived elemental sulfur (S0) with δ34S ≪ 0 and Δ33S ≫ 0‰. The sulfur isotope data suggest that sulfidization was largely driven by reduction of intermixed MDF–SO4 2 − and MIF–SO4 2 − (bulk signature of δ34S ~ 5‰ and Δ33S ~ −1.4‰), and dilution of produced H2S (δ34S ~ −12‰ and Δ33S ~ −1.4‰) by native H2S in magmatic–hydrothermal fluids. The δ34S shifts (up to ~17‰) generated by sulfate reduction are consistent with both thermochemical reactions and influence of sulfate–cycling microbes, the latter which may have facilitated rapid pyrite precipitation and preservation of microbial remains that are entombed within the petrogenetically earliest pyrite generation of stromatolites. Collectively, our data are consistent with ancient stromatolite growth in proximity to shallow marine hydrothermal vents, where hydrothermal fluids contributed to sulfidization that may have been further influenced by sulfur–cycling microbes.
AB - This study reports in–situ sulfur isotope analyses (32S, 33S, 34S and 36S) of pyrite in strongly sulfidized stromatolites from the ~3.48 billion–year–old Dresser Formation, Pilbara Craton, Australia. These data shed light on sulfur reservoirs and sulfide precipitation processes and provide clues for the contribution of sulfur–cycling microbes to sulfidization. Sulfur isotope signatures derived from mass dependent fractionation (MDF; monitored by δ34S) and mass independent fractionation (MIF; here Δ33S and Δ36S) of pyrite in stromatolites, and of microscopic pyrite within associated barite, allow for the identification of distinctive sulfur sources: i) magmatic–hydrothermal sulfide (H2S) with δ34S and Δ33S ~ 0%; ii) magmatic–hydrothermal sulfate (SO4 2 −) with a MDF signature (MDF–SO4 2 −; δ34S ~ 10‰ and Δ33S ~ 0‰; iii) photochemically–derived sulfate with a MIF signature (MIF–SO4; δ34S ~ −6‰ and Δ33S ~ −3.0‰); iv) photochemically–derived elemental sulfur (S0) with δ34S ≪ 0 and Δ33S ≫ 0‰. The sulfur isotope data suggest that sulfidization was largely driven by reduction of intermixed MDF–SO4 2 − and MIF–SO4 2 − (bulk signature of δ34S ~ 5‰ and Δ33S ~ −1.4‰), and dilution of produced H2S (δ34S ~ −12‰ and Δ33S ~ −1.4‰) by native H2S in magmatic–hydrothermal fluids. The δ34S shifts (up to ~17‰) generated by sulfate reduction are consistent with both thermochemical reactions and influence of sulfate–cycling microbes, the latter which may have facilitated rapid pyrite precipitation and preservation of microbial remains that are entombed within the petrogenetically earliest pyrite generation of stromatolites. Collectively, our data are consistent with ancient stromatolite growth in proximity to shallow marine hydrothermal vents, where hydrothermal fluids contributed to sulfidization that may have been further influenced by sulfur–cycling microbes.
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U2 - 10.1016/j.chemgeo.2020.119488
DO - 10.1016/j.chemgeo.2020.119488
M3 - Article
AN - SCOPUS:85079099780
VL - 538
JO - Chemical Geology
JF - Chemical Geology
SN - 0009-2541
M1 - 119488
ER -