Data/hora: 18/06/2024 12:26:13

Provedor de dados: | 5
País: | France
Título: | Formation and evolution of glauconite in the Demerara Contourite depositional system related to NADW circulation changes during late Quaternary (French Guiana)
Autores: | Tallobre, Cédric; Giresse, Pierre; Bassetti, Maria-angela; Loncke, Lies; Bayon, Germain; Buscail, Roselyne; Tudryn, Alina; Zaragosi, Sébastien.
Data: | 2019-06
Ano: | 2019
Palavras-chave: | Marginal plateau; Contourite; Glauconite; Demerara plateau.
Resumo: | 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 these data and using the glauconitic authigenic mineral as proxy for inferring the degree of winnowing at the sediment-water interface, we might put forward the hypothesis that the intensity of NADW is higher during the glacial stages and lower during interglacial periods.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00485/59665/62724.pdf

DOI:10.1016/j.jsames.2019.03.011

https://archimer.ifremer.fr/doc/00485/59665/

Editor: | Elsevier BV
Formato: | application/pdf
Fonte: | Journal Of South American Earth Sciences (0895-9811) (Elsevier BV), 2019-06 , Vol. 92 , P. 167-183

Fonte:

info:eu-repo/semantics/openAccess

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