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- Chi Fru, Ernest, et al.
(författare)
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Arsenic stress after the Proterozoic glaciations
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Protection against arsenic damage in organisms positioned deep in the tree of life points to early evolutionary sensitization. Here, marine sedimentary records reveal a Proterozoic arsenic concentration patterned to glacial-interglacial ages. The low glacial and high interglacial sedimentary arsenic concentrations, suggest deteriorating habitable marine conditions may have coincided with atmospheric oxygen decline after ~2.1 billion years ago. A similar intensification of near continental margin sedimentary arsenic levels after the Cryogenian glaciations is also associated with amplified continental weathering. However, interpreted atmospheric oxygen increase at this time, suggests that the marine biosphere had widely adapted to the reorganization of global marine elemental cycles by glaciations. Such a glacially induced biogeochemical bridge would have produced physiologically robust communities that enabled increased oxygenation of the ocean-atmosphere system and the radiation of the complex Ediacaran-Cambrian life.
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| 2. |
- Chi Fru, Ernest, et al.
(författare)
-
Proterozoic arsenic dynamics controlled by glaciations
- 2015
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Ingår i: Abstracts of the 25<sup>th</sup>Goldschmidt Conference, Prague. ; , s. 537-537
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Konferensbidrag (refereegranskat)abstract
- Increased chemical weathering of trace elements from land to ocean after the Great Oxidation Event is often correlated to biological stimulation near the ocean margins. However, life had to develop strategies to combat the sudden bioavailability of a range of toxic/redox-sensitive elements that became widely accessible because of the GOE. Here, sedimentary As marine records reveal a cyclic Proterozoic arsenic concentration pattern influenced by glacial-interglacial cycles. Postglacial sedimentary arsenic concentrations suggest deterioration of habitable marine conditions may have coincided with atmospheric oxygen decline after ~2.1 billion years ago (Ga). This changed after ~0.58 Ga when marine biota developed widespread stress responses against postglacial reorganization of global marine elemental cycles, producing physiologically robust communities that enabled increased oxygenation of the atmosphere-ocean system and radiation of complex life.
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