| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
Palaeoproterozoic oxygenated oceans following the Lomagundi-Jatuli Event
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| Autores: |
Mand, Kaarel
Lalonde, Stefan
Robbins, Leslie J.
Thoby, Marie
Paiste, Kart
Kreitsmann, Timmu
Paiste, Paarn
Reinhard, Christopher T.
Romashkin, Alexandr E.
Planavsky, Noah J.
Kirsimae, Kalle
Lepland, Aivo
Konhauser, Kurt O.
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| Data: |
2020-04
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| Ano: |
2020
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| Resumo: |
The oceans probably remained well-oxygenated for millions of years after the Palaeoproterozoic Lomagundi-Jatuli Event, according to high concentrations and isotope signatures of redox-sensitive metals in the 2-billion-year-old Zaonega Formation, Russia. The approximately 2,220-2,060 million years old Lomagundi-Jatuli Event was the longest positive carbon isotope excursion in Earth history and is traditionally interpreted to reflect an increased organic carbon burial and a transient rise in atmospheric O-2. However, it is widely held that O-2 levels collapsed for more than a billion years after this. Here we show that black shales postdating the Lomagundi-Jatuli Event from the approximately 2,000 million years old Zaonega Formation contain the highest redox-sensitive trace metal concentrations reported in sediments deposited before the Neoproterozoic (maximum concentrations of Mo = 1,009 mu g g(-1), U = 238 mu g g(-1) and Re = 516 ng g(-1)). This unit also contains the most positive Precambrian shale U isotope values measured to date (maximum U-238/U-235 ratio of 0.79 parts per thousand), which provides novel evidence that there was a transition to modern-like biogeochemical cycling during the Palaeoproterozoic. Although these records do not preclude a return to anoxia during the Palaeoproterozoic, they uniquely suggest that the oceans remained well-oxygenated millions of years after the termination of the Lomagundi-Jatuli Event.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
https://archimer.ifremer.fr/doc/00663/77461/82873.pdf
DOI:10.1038/s41561-020-0558-5
https://archimer.ifremer.fr/doc/00663/77461/
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| Editor: |
Nature Publishing Group
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| Formato: |
application/pdf
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| Fonte: |
Nature Geoscience (1752-0894) (Nature Publishing Group), 2020-04 , Vol. 13 , N. 4 , P. 302-306
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| Direitos: |
info:eu-repo/semantics/openAccess
restricted use
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