Abstract
| Original language | English |
|---|---|
| Article number | 4505 |
| Journal | Nature Communications |
| Volume | 9 |
| DOIs | |
| Publication status | Published - 29 Oct 2018 |
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Keywords
- astrobiology
- element cycles
- environmental microbiology
- palaeontology
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Reduction spheroids preserve a uranium isotope record of the ancient deep continental biosphere. / McMahon, Sean (Corresponding Author); Hood, Ashleigh v. S. ; Parnell, John; Bowden, Stephen.
In: Nature Communications, Vol. 9, 4505, 29.10.2018.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Reduction spheroids preserve a uranium isotope record of the ancient deep continental biosphere
AU - McMahon, Sean
AU - Hood, Ashleigh v. S.
AU - Parnell, John
AU - Bowden, Stephen
N1 - S.M. acknowledges the support of the NASA Astrobiology Institute grant NNA13AA90A, Foundations of Complex Life, Evolution, Preservation and Detection on Earth and Beyond, and the European Union’s Horizon 2020 Research and Innovation Programme under Marie Skłodowska-Curie grant agreement 747877. Av.S.H. was supported by a NASA Astrobiology Institute Postdoctoral Fellowship and acknowledges the support of Xiangli Wang and Devon Cole for lab assistance. S.M. and Av.S.H. thank Noah Planavsky for technical advice, lab support, and comments on an early draft. J.P. was supported by NERC under grant number NE/L001764/1. The isotope facility at SUERC is supported by NERC. The authors thank the two anonymous referees for constructive criticisms that improved the manuscript.
PY - 2018/10/29
Y1 - 2018/10/29
N2 - Life on Earth extends to several kilometres below the land surface and seafloor. This deep biosphere is second only to plants in its total biomass, is metabolically active and diverse, and is likely to have played critical roles over geological time in the evolution of microbial diversity, diagenetic processes and biogeochemical cycles. However, these roles are obscured by a paucity of fossil and geochemical evidence. Here we apply the recently developed uranium-isotope proxy for biological uranium reduction to reduction spheroids in continental rocks (red beds). Although these common palaeo-redox features have previously been suggested to reflect deep bacterial activity, unequivocal evidence for biogenicity has been lacking. Our analyses reveal that the uranium present in reduction spheroids is isotopically heavy, which is most parsimoniously explained as a signal of ancient bacterial uranium reduction, revealing a compelling record of Earth’s deep biosphere.
AB - Life on Earth extends to several kilometres below the land surface and seafloor. This deep biosphere is second only to plants in its total biomass, is metabolically active and diverse, and is likely to have played critical roles over geological time in the evolution of microbial diversity, diagenetic processes and biogeochemical cycles. However, these roles are obscured by a paucity of fossil and geochemical evidence. Here we apply the recently developed uranium-isotope proxy for biological uranium reduction to reduction spheroids in continental rocks (red beds). Although these common palaeo-redox features have previously been suggested to reflect deep bacterial activity, unequivocal evidence for biogenicity has been lacking. Our analyses reveal that the uranium present in reduction spheroids is isotopically heavy, which is most parsimoniously explained as a signal of ancient bacterial uranium reduction, revealing a compelling record of Earth’s deep biosphere.
KW - astrobiology
KW - element cycles
KW - environmental microbiology
KW - palaeontology
U2 - 10.1038/s41467-018-06974-9
DO - 10.1038/s41467-018-06974-9
M3 - Article
VL - 9
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
M1 - 4505
ER -