RABOUILLE, Christophe; DENNIELOU, B.; BAUDIN, François; RAIMONET, Mélanie; DROZ, L.; KHRIPOUNOFF, A.; MARTINEZ, Philippe; MEJANELLE, L.; MICHALOPOULOS, P.; PASTOR, L.; PRUSKI, A.M.; RAGUENEAU, Olivier; REYSS, J.-L.; RUFFINE, L.; SCHNYDER, J.; STETTEN, E.; TAILLEFERT, M.; TOUROLLE, J.; OLU, K.

doi:10.1016/j.quascirev.2019.07.036

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RABOUILLE, Christophe
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Océan et Interfaces [OCEANIS]

DENNIELOU, B.
Unité Géosciences Marines [GM]

BAUDIN, François
Institut des Sciences de la Terre de Paris [iSTeP]

Langue

Article de revue

Ce document a été publié dans

Quaternary Science Reviews. 2019-10-15, vol. 222, p. 105854

Résumé en anglais

Carbon and silicon cycles at the Earth surface are linked to long-term variations of atmospheric CO2 and oceanic primary production. In these cycles, the river-sea interface is considered a biogeochemical hotspot, and deltas presently receive and preserve a major fraction of riverine particles in shallow water sediments. In contrast, periods of glacial maximum lowstand were characterized by massive exports of sediments to the deep-sea via submarine canyons and accumulation in deep-sea fans. Here, we calculate present-day mass balances for organic carbon (OC) and amorphous silica (aSi) in the terminal lobe complex of the Congo River deep-sea fan as an analogue for glacial periods. We show that this lobe complex constitutes a megasink with the current accumulation of 18 and 35% of the OC and aSi river input, respectively. This increases the estimates of organic carbon burial by 19% in the South Atlantic Ocean in a zone representing less than 0.01% of the basin. These megasinks might have played a role in carbon trapping in oceanic sediments during glacial times.< Réduire

Mots clés en anglais

Sedimentology-marine cores

Organic geochemistry

South Atlantic

Inorganic geochemistry

Present

Paleoceanography

ACL

URI

https://oskar-bordeaux.fr/handle/20.500.12278/188456

DOI

http://dx.doi.org/10.1016/j.quascirev.2019.07.036

Project ANR

Transfert de carbone organique et fonctionnement des écosystèmes dans les lobes terminaux de l'éventail sous-marin du Congo - ANR-11-BS56-0030

Unités de recherche

EPOC : Environnements et Paléoenvironnements Océaniques et Continentaux - UMR 5805