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| Yu, Zhaojie; Colin, Christophe; Douville, Eric; Meynadier, Laure; Duchamp-alphonse, Stephanie; Sepulcre, Sophie; Wan, Shiming; Song, Lina; Wu, Qiong; Xu, Zhaokai; Bassinot, Frank. |
| The dissolved Yttrium (Y) and Rare Earth Element (REE) concentrations of seawater samples collected along a north-south hydrological transect within the Bay of Bengal (BoB) have been analyzed to estimate contributions of the Ganges and Brahmaputra (G-B) river inputs to the dissolved REE distribution of the Northern Indian Ocean. Surface water masses of the BoB are characterized by Y/Ho ratios (84) intermediate between the G-B river suspended sediment (41) and water mass from the South Indian Ocean (93). Co-variation of MREE (Middle REE, Sm) and LREE (Light REE, La) concentrations suggests that the dissolved REEs in surface waters (upper 100 m depth) of the BoB (Sm/La = 0.21) appear to derive mainly from the freshwater discharge of the G-B river system. In... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00377/48845/49277.pdf |
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| Duchamp-alphonse, Stephanie; Siani, Giuseppe; Michel, Elisabeth; Beaufort, Luc; Gally, Yves; Jaccard, Samuel L.. |
| Several synergistic mechanisms were likely involved in the last deglacial atmospheric pCO2 rise. Leading hypotheses invoke a release of deep-ocean carbon through enhanced convection in the Southern Ocean (SO) and concomitant decreased efficiency of the global soft-tissue pump (STP). However, the temporal evolution of both the STP and the carbonate counter pump (CCP) remains unclear, thus preventing the evaluation of their contributions to the pCO2 rise. Here we present sedimentary coccolith records combined with export production reconstructions from the Subantarctic Pacific to document the leverage the SO biological carbon pump (BCP) has imposed on deglacial pCO2. Our data suggest a weakening of BCP during the phases of carbon outgassing, due in part to... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55643/57288.pdf |
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| Joussain, Ronan; Liu, Zhifei; Colin, Christophe; Duchamp-alphonse, Stephanie; Yu, Zhaojie; Moreno, Eva; Fournier, Lea; Zaragosi, Sebastien; Dapoigny, Arnaud; Meynadier, Laure; Bassinot, Franck. |
| Mineralogical and geochemical analyses conducted on cores located on the active channel-levee system of the northern Bengal Fan are used to establish changes in the weathering pattern and the sediment transport of the Himalayan system, and evaluate the effect of Indian summer monsoon rainfall during the Holocene. Our data indicate that during the Holocene, sediments from the northern Bengal Fan originate mainly from the G-B river system without any significant changes in the relative contribution of these rivers. From 9.8 to around 6 ka, relatively low smectite/(illite+chlorite) ratios and relatively high K/Si* ratios indicate high physical denudation rates of the Himalayan highlands together with a rapid transfer of the detrital material to the Bengal... |
| Tipo: Text |
Palavras-chave: Bengal Fan; Chemical weathering; Sr and Nd isotopic compositions; Physical erosion; Clay mineralogy. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00393/50416/51143.pdf |
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