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
|Author(s)||Ballini M1, Kissel C1, Colin C2, Richter T3|
|Affiliation(s)||1 : Lab Sci Climat & Environm, Unite Mixte CEA CNRS, F-91198 Gif Sur Yvette, France.
2 : Univ Paris 11, Lab Interact & Dynam Environm Surface, F-91405 Orsay, France.
3 : Royal Netherlands Inst Sea Res, NL-1790 AB Den Burg, Netherlands.
|Source||Geochemistry Geophysics Geosystems (1525-2027) (Amer Geophysical Union), 2006-02 , Vol. 7 , N. 2 / Q02N01 , P. 1-16|
|WOS© Times Cited||26|
|Keyword(s)||glacial period, Dansgaard-Oeschger cycles, North Atlantic, bottom water circulation, magnetic properties, clay minerals|
|Abstract|| 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.|