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| Tallobre, Cédric; Giresse, Pierre; Bassetti, Maria-angela; Loncke, Lies; Bayon, Germain; Buscail, Roselyne; Tudryn, Alina; Zaragosi, Sébastien. |
| The Demerara Plateau is a marginal plateau which forms a bathymetric relief on the sea floor. Here, contourite deposits have been studied in detail, following the recent discovery of contourite sequences likely related to the bottom currents and linked both to contour current and peculiar sea-floor morphology. A chronostratigraphic framework, based on δ18O relative variations and palaeomagnetic events in sediment cores allows correlating sediment processes to current intensity changes and major climate phases (glacial or interglacial). The studied sediments are enriched in glauconitic grains. In addition, the glauconite mineralogical maturity can easily correlate to low sedimentation rate and slightly energetic bottom currents on the seafloor. Based on... |
| Tipo: Text |
Palavras-chave: Marginal plateau; Contourite; Glauconite; Demerara plateau. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00485/59665/62724.pdf |
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| Zaragosi, Sébastien; Bourillet, Jean-francois; Eynaud, Frédérique; Toucanne, Samuel; Denhard, Benjamin; Van Toer, Aurélie; Lanfumey, Valentine. |
| The compilation of results obtained on three giant piston cores from the Whittard, Shamrock and Guilcher turbidite levees reveals a high-resolution stratigraphic record for the Bay of Biscay. Due to the abundance of reworked sediments in these sedimentary environments, a specific methodological approach, based on an X-ray-assisted subsampling phase associated with sedimentological, geochemical and micropalaeontological analyses, was implemented. With an accurate chronological framework, this multi-proxy investigation provides observations on the 'Fleuve Manche' palaeoriver and the British-Irish Ice Sheet (BIS) histories over the last 20,000 years. The results obtained highlight the direct influence of the decay of the BIS on the Bay of Biscay deep-sea... |
| Tipo: Text |
Palavras-chave: Sedimentation; Glaciation; Turbidity; Deep sea; Bay of Biscay; French Atlantic margin. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2142.pdf |
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| Moreno, Eva; Caroir, Fabien; Fournier, Lea; Fauquembergue, Kelly; Zaragosi, Sébastien; Joussain, Ronan; Colin, Christophe; Blanc-valleron, Marie-madeleine; Baudin, François; De Garidel-thoron, Thibault; Valet, Jean Pierre; Bassinot, Franck. |
| We present here a study based on the Anisotropy of Magnetic Susceptibility (AMS) and magnetic mineralogy carried out on the composite core MD17&18taken from the eastern levee of the active channel of the middle Bengal Fan in the Indian Ocean. Based on C-14 dating, the sedimentary sequence covers 9.8 ka in 39 m of sediment. It therefore records at very high resolution the variations in continental material exported to the ocean by the Ganges-Brahmaputra river system during the Holocene. This sequence was divided into two units according to turbidite activity: Unit 1 from 9.8 to 9.2 ka cal. Representing 39 m of coarse-grained turbidite sequences (coarse silts to fine sands) and extremely high sedimentation rates. Unit 2 of 9.2 ka cal. BP to the present... |
| Tipo: Text |
Palavras-chave: Bengal fan; Holocene; Turbidite activity; Magnetic fabric; Magnetic mineralogy. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76388/77402.pdf |
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