TY - JOUR
T1 - A rare glimpse of paleoarchean life
T2 - Geobiology of an exceptionally preserved microbial mat facies from the 3.4 ga strelley pool formation, Western Australia
AU - Duda, Jan Peter
AU - Van Kranendonk, Martin J.
AU - Thiel, Volker
AU - Ionescu, Danny
AU - Strauss, Harald
AU - Schäfer, Nadine
AU - Reitner, Joachim
N1 - Funding Information:
Funding: Financial support was provided by Deutsche Forschungsgemeinschaft (grant DU 1450/ 3-1, DFG Priority Programme 1833 „Building a Habitable Earth“), Courant Research Centre of the University Göttingen (DFG, German Excellence Program), Göttingen Academy of Sciences and Humanities, University of New South Wales, and the Sloan Foundation. University of Göttingen provided
Funding Information:
financial support for open access (open Access Publication Funds).
Funding Information:
Financial support was provided by Deutsche Forschungsgemeinschaft (grant DU 1450/3-1, DFG Priority Programme 1833 "Building a Habitable Earth"), Courant Research Centre of the University G?ttingen (DFG, German Excellence Program), G?ttingen Academy of Sciences and Humanities, University of New South Wales, and the Sloan Foundation. University of G?ttingen provided financial support for open access (open Access Publication Funds).
Publisher Copyright:
© 2016 Duda et al.
PY - 2016/1
Y1 - 2016/1
N2 - Paleoarchean rocks from the Pilbara Craton of Western Australia provide a variety of clues to the existence of early life on Earth, such as stromatolites, putative microfossils and geochemical signatures of microbial activity. However, some of these features have also been explained by non-biological processes. Further lines of evidence are therefore required to convincingly argue for the presence of microbial life. Here we describe a new type of microbial mat facies from the 3.4 Ga Strelley Pool Formation, which directly overlies well known stromatolitic carbonates from the same formation. This microbial mat facies consists of laminated, very fine-grained black cherts with discontinuous white quartz layers and lenses, and contains small domical stromatolites and wind-blown crescentic ripples. Lightand cathodoluminescence microscopy, Raman spectroscopy, and time of flight-secondary ion mass spectrometry (ToF-SIMS) reveal a spatial association of carbonates, organic material, and highly abundant framboidal pyrite within the black cherts. Nano secondary ion mass spectrometry (NanoSIMS) confirmed the presence of distinct spheroidal carbonate bodies up to several tens of μm that are surrounded by organic material and pyrite. These aggregates are interpreted as biogenic. Comparison with Phanerozoic analogues indicates that the facies represents microbial mats formed in a shallow marine environment. Carbonate precipitation and silicification by hydrothermal fluids occurred during sedimentation and earliest diagenesis. The deciphered environment, as well as the δ13C signature of bulk organic matter (-35.3‰), are in accord with the presence of photoautotrophs. At the same time, highly abundant framboidal pyrite exhibits a sulfur isotopic signature (δ34S = +3.05‰; Δ33S = 0.268‰; and Δ36S = -0.282‰) that is consistent with microbial sulfate reduction. Taken together, our results strongly support a microbial mat origin of the black chert facies, thus providing another line of evidence for life in the 3.4 Ga Strelley Pool Formation.
AB - Paleoarchean rocks from the Pilbara Craton of Western Australia provide a variety of clues to the existence of early life on Earth, such as stromatolites, putative microfossils and geochemical signatures of microbial activity. However, some of these features have also been explained by non-biological processes. Further lines of evidence are therefore required to convincingly argue for the presence of microbial life. Here we describe a new type of microbial mat facies from the 3.4 Ga Strelley Pool Formation, which directly overlies well known stromatolitic carbonates from the same formation. This microbial mat facies consists of laminated, very fine-grained black cherts with discontinuous white quartz layers and lenses, and contains small domical stromatolites and wind-blown crescentic ripples. Lightand cathodoluminescence microscopy, Raman spectroscopy, and time of flight-secondary ion mass spectrometry (ToF-SIMS) reveal a spatial association of carbonates, organic material, and highly abundant framboidal pyrite within the black cherts. Nano secondary ion mass spectrometry (NanoSIMS) confirmed the presence of distinct spheroidal carbonate bodies up to several tens of μm that are surrounded by organic material and pyrite. These aggregates are interpreted as biogenic. Comparison with Phanerozoic analogues indicates that the facies represents microbial mats formed in a shallow marine environment. Carbonate precipitation and silicification by hydrothermal fluids occurred during sedimentation and earliest diagenesis. The deciphered environment, as well as the δ13C signature of bulk organic matter (-35.3‰), are in accord with the presence of photoautotrophs. At the same time, highly abundant framboidal pyrite exhibits a sulfur isotopic signature (δ34S = +3.05‰; Δ33S = 0.268‰; and Δ36S = -0.282‰) that is consistent with microbial sulfate reduction. Taken together, our results strongly support a microbial mat origin of the black chert facies, thus providing another line of evidence for life in the 3.4 Ga Strelley Pool Formation.
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U2 - 10.1371/journal.pone.0147629
DO - 10.1371/journal.pone.0147629
M3 - Article
C2 - 26807732
AN - SCOPUS:84978835424
VL - 11
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 1
M1 - e0147629
ER -
