Increased input of circumpolar deep water-borne detritus to the glacial SE Atlantic Ocean

• Published in: Geochemistry, Geophysics, Geosystems
• Main Authors: Bayon, Germain, German, Christopher R., Nesbitt, Robert W., Bertrand, Philippe, Schneider, Ralph R.
• Other Authors: Domaines Océaniques (LDO), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2003
• Subjects: Neodymium isotopes; detrital fractions; South Atlantic; deep water circulation; [SDU]Sciences of the Universe [physics]; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; NADW; North Atlantic Deep Water; North Atlantic
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03619026; https://hal-insu.archives-ouvertes.fr/insu-03619026/document; https://hal-insu.archives-ouvertes.fr/insu-03619026/file/Geochem%20Geophys%20Geosyst%20-%202003%20-%20Bayon%20-%20Increased%20input%20of%20circumpolar%20deep%20water%25u2010borne%20detritus%20to%20the%20glacial%20SE.pdf; https://doi.org/10.1029/2002GC000371

International audience Analysis of radiogenic isotopes in marine sediments can provide useful information on the provenance and transport of detrital material, directly relevant to paleoceanographic investigations. Here we show that the detrital Nd isotopic composition of recent SE Atlantic marine sediments matches the complex modern-day hydrography. In these same cores, glacial-interglacial isotopic variations are consistent with previous investigations (using different paleoceanographic proxies), which have shown that the relative influence of North Atlantic Deep Water (NADW) into the South Atlantic was reduced during glacial periods. In a novel departure, however, we also calculate the mass accumulation rates of terrigenous material delivered by each of Circumpolar Deep Water (CDW) and NADW to demonstrate that the accumulation of detritus delivered by CDW was enhanced significantly in the glacial South Atlantic. This enhanced transport flux could be explained by an increased flow of CDW into the glacial South Atlantic and/or an increased concentration of suspended terrigenous material transported by glacial CDW.