Palaeoceanographic and hydrodynamic variability for the last 47 kyr in the southern Gulf of Cádiz (Atlantic Moroccan margin): Sedimentary and climatic implications

• Published in: The Depositional Record
• Main Authors: Vandorpe, Thomas D., Delivet, Stanislas, Blamart, Dominique, Wienberg, Claudia, Bassinot, Franck C., Mienis, Furu, Stuut, Jan Berend W., van Rooij, David
• Other Authors: University College Ghent, Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), 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)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Bremen, Royal Netherlands Institute for Sea Research (NIOZ), He3412-18; EC FP6 IP HERMES; European Science Foundation, ESF; Belgian Federal Science Policy Office, BELSPO; Fonds Wetenschappelijk Onderzoek, FWO: 1524713N, This study was carried out within the framework of a Ghent University BOF ‘Starting Grant’. It was additionally part of the FWO project Contourite‐3D (n° 1524713N). The authors wish to acknowledge the captains and crews of the campaigns on board of the R/V Marion Dufresne cruise MD169‐MICROSYSTEMS (founded by European Science Foundation, EuroDIVERSITY within the framework of project EC FP6 IP HERMES) and of the R/V Belgica cruise 2013/16‐COMIC. Shiptime on board R/V Belgica was provided by BELSPO and RBINS–OD Nature. Stable isotopes analyses were performed on Panoply Platerform Mass spectrometer at LSCE. A special thanks to Gulay Isguder who helped us in the foraminifera determination and to Alice Matossian and Lotte Verweirder for providing additional bulk grain sizes on the condensed section. This study contributes to the Deutsche Forschungsgemeinschaft DFG‐project ‘MoccaMeBo’ (He3412‐18). Two anonymous reviewers helped a lot in improving the content of the manuscript., This study was carried out within the framework of a Ghent University BOF ‘Starting Grant’. It was additionally part of the FWO project Contourite-3D (n° 1524713N). The authors wish to acknowledge the captains and crews of the campaigns on board of the R/V Marion Dufresne cruise MD169-MICROSYSTEMS (founded by European Science Foundation, EuroDIVERSITY within the framework of project EC FP6 IP HERMES) and of the R/V Belgica cruise 2013/16-COMIC. Shiptime on board R/V Belgica was provided by BELSPO and RBINS–OD Nature. Stable isotopes analyses were performed on Panoply Platerform Mass spectrometer at LSCE. A special thanks to Gulay Isguder who helped us in the foraminifera determination and to Alice Matossian and Lotte Verweirder for providing additional bulk grain sizes on the condensed section. This study contributes to the Deutsche Forschungsgemeinschaft DFG-project ‘MoccaMeBo’ (He3412-18). Two anonymous reviewers helped a lot in improving the content of the manuscript.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: aeolian dust; Antarctic Intermediate Water; Azores Front; bottom currents; cold-water corals; Pen Duick drift; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Antarctic; The Antarctic; Antarc*; Dansgaard-Oeschger events; North Atlantic
• Online Access: https://hal.science/hal-04122478; https://hal.science/hal-04122478/document; https://hal.science/hal-04122478/file/The%20Depositional%20Record%20-%202022%20-%20Vandorpe%20-%20Palaeoceanographic%20and%20hydrodynamic%20variability%20for%20the%20last%2047%20kyr%20in%20the.pdf; https://doi.org/10.1002/dep2.212

International audience X-ray fluorescence, grain-size and oxygen and carbon stable isotope measurements of a 33 m long piston core, recovered from the Pen Duick drift located at the foot of the prominent Pen Duick Escarpment (Atlantic Moroccan margin), are combined to decipher past oceanographic conditions. The data indicate that, similar to the northern Gulf of Cádiz, the Azores Front exerts a major control on the palaeoclimatology of the region. Contrasting the northern Gulf of Cádiz, where Mediterranean Outflow Water is the main water mass at similar water depths, the palaeoceanography of the studied area is mostly influenced by the amount of Antarctic Intermediate Water advected from the south. The density contrast between the Antarctic Intermediate Water and the overlying North Atlantic Central Water determined the strength of the prevailing internal tides and corresponding high current speeds, which drastically impacted the sedimentary record. The most notable impact is the presence of a 7.8 kyr condensed section (30.5–22.7 ka bp). The formation of the Pen Duick sediment drift was not just controlled by the strength of the bottom currents and the intensity of the internal tides, but also by the amount of (aeolian) sediment supplied to the region. Although variable, drift-growth phases seem to mainly occur during colder periods of the last glacial, that is Heinrich and Dansgaard-Oeschger events during Marine Isotope Stage 3 and late Marine Isotope Stage 2. These periods, characterised by increased aeolian dust supply and higher bottom currents, coincide with a phase of prolific cold-water coral growth and enhanced coral mound formation as recorded in numerous cores obtained from the southern Gulf of Cádiz. This implies that both records (on and off mound cores) are pivotal to provide the complete picture of the palaeoclimatic and palaeoceanographic conditions in the region.