Deep-water mass source and dynamic associated with rapid climatic variations during the last glacial stage in the North Atlantic: A multiproxy investigation of the detrital fraction of deep-sea sediments

• Published in: Geochemistry, Geophysics, Geosystems
• Main Authors: Ballini, M., Kissel, C., Colin, C., Richter, T.
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Climat et Magnétisme (CLIMAG), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Royal Netherlands Institute for Sea Research (NIOZ)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2006
• Subjects: bottom water circulation; clay minerals; magnetic properties; glacial period; Dansgaard-Oeschger cycles; North Atlantic; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Irminger Basin; Reykjanes; NADW; North Atlantic Deep Water
• Online Access: https://hal.archives-ouvertes.fr/hal-03118259; https://hal.archives-ouvertes.fr/hal-03118259/document; https://hal.archives-ouvertes.fr/hal-03118259/file/2005GC001070.pdf; https://doi.org/10.1029/2005GC001070

International audience In order to investigate North Atlantic Deep Water (NADW) dynamics and variability during the last glacial stage, a very high resolution multiproxy analysis of the detrital fraction of sediments deposited during Heinrich event 4 and Dansgaard-Oeschger cycles 8 and 7 has been conducted on three deep-sea cores. These cores are distributed along the path of the North Atlantic Deep Water from the Faeroe Shetland Channel to the Reykjanes ridge and the Irminger basin. The concentration in fine-grained magnetites, the Ti-content, and the smectite percentage within the clay minerals show similar and coeval fluctuations at each site and are comparable from one site to the other. This is the imprint of the detrital fraction originating from the northern basaltic provinces and transported to the studied sites. The average grain size in the fine fraction indicates a transport by deep-sea currents. Therefore the observed fluctuations illustrate changes in the vigor of the bottom currents associated with the NADW with weak currents during cold periods (Heinrich 4 and stadials) and reactivation of the bottom circulation during interstadials.