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Fontorbe, Guillaume; Frings, Patrick J.; De La Rocha, Christina L.; Hendry, Katharine R.; Conley, Daniel J.. |
The Paleocene‐Eocene Thermal Maximum (PETM, ca. 56 Ma) is marked by a negative carbon isotope excursion (CIE) and increased global temperatures. The CIE is thought to result from the release of 13C‐depleted carbon, although the source(s) of carbon and triggers for its release, its rate of release, and the mechanisms by which the Earth system recovered are all debated. Many of the proposed mechanisms for the onset and recovery phases of the PETM make testable predictions about the marine silica cycle, making silicon isotope records a promising tool to address open questions about the PETM. We analyzed silicon isotope ratios (δ30Si) in radiolarian tests and sponge spicules from the Western North Atlantic (ODP Site 1051) across the PETM. Radiolarian δ30Si... |
Tipo: Text |
Palavras-chave: Paleocene‐Eocene Thermal Maximum; Silicon biogeochemical cycle; Silicon isotopes; Weathering. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00627/73939/73287.pdf |
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Frings, Patrick J.; Clymans, Wim; Fontorbe, Guillaume; De La Rocha, Christina L.; Conley, Daniel J.. |
The silicon isotope composition of biogenic silica (delta Si-30(BSi)) in the ocean is a function of the delta Si-30 of the available dissolved Si (DSi; H2SiO4), the degree of utilisation of the available DSi, and, for some organisms, the concentration of DSi. This makes delta Si-30(BSi) in sediment archives a promising proxy for past DSi concentrations and utilisation. At steady-state, mean delta Si-30(BSi) must equal a weighted average of the inputs, the majority of which are of continental origin. Variation in the functioning of the continental Si cycle on timescales similar to the residence time of DSi in the ocean (similar to 10 ka) may therefore contribute to downcore variability in delta Si-30(BSi) on millennial or longer time-scales. The direction... |
Tipo: Text |
Palavras-chave: Global silicon cycle; Biogenic silica; Silicon isotopes; LGM; Palaeoceanography; Biogeochemical cycling. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53252/54714.pdf |
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