The giant Mauritanian cold-water coral mound province: Oxygen control on coral mound formation

• Published in: Quaternary Science Reviews
• Main Authors: Wienberg, Claudia, Titschack, Jürgen, Freiwald, André, Frank, Norbert, Lundälv, Tomas, Taviani, Marco, Beuck, Lydia, Schröder-Ritzrau, Andrea, Krengel, Thomas, Hebbeln, Dierk
• Other Authors: Center for Marine Environmental Sciences Bremen (MARUM), Universität Bremen, Senckenberg am Meer, 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), Géochrononologie Traceurs Archéométrie (GEOTRAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-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)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Institute of Environmental Physics Heidelberg (IUP), Universität Heidelberg Heidelberg = Heidelberg University, Göteborgs Universitet = University of Gothenburg (GU), Istituto di Scienze Marine Bologna (ISMAR), Istituto di Science Marine (ISMAR ), National Research Council of Italy, Woods Hole Oceanographic Institution (WHOI), Stazione Zoologica Anton Dohrn (SZN)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Lophelia pertusa; Mound aggradation rate; Last glacial; Dissolved oxygen concentration; South Atlantic Central Water; Mauritanian margin; Coral mound; Submarine canyon; Uranium-series dating; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
• Online Access: https://hal.science/hal-01806884; https://hal.science/hal-01806884/document; https://hal.science/hal-01806884/file/1-s2.0-S0277379117304729-main.pdf; https://doi.org/10.1016/j.quascirev.2018.02.012

International audience The largest coherent cold-water coral (CWC) mound province in the Atlantic Ocean exists along the Mauritanian margin, where up to 100 m high mounds extend over a distance of ∼400 km, arranged in two slope-parallel chains in 400–550 m water depth. Additionally, CWCs are present in the numerous submarine canyons with isolated coral mounds being developed on some canyon flanks. Seventy-seven Uranium-series coral ages were assessed to elucidate the timing of CWC colonisation and coral mound development along the Mauritanian margin for the last ∼120,000 years. Our results show that CWCs were present on the mounds during the Last Interglacial, though in low numbers corresponding to coral mound aggradation rates of 16 cm kyr−1. Most prolific periods for CWC growth are identified for the last glacial and deglaciation, resulting in enhanced mound aggradation (>1000 cm kyr−1), before mound formation stagnated along the entire margin with the onset of the Holocene. Until today, the Mauritanian mounds are in a dormant state with only scarce CWC growth. In the canyons, live CWCs are abundant since the Late Holocene at least. Thus, the canyons may serve as a refuge to CWCs potentially enabling the observed modest re-colonisation pulse on the mounds along the open slope. The timing and rate of the pre-Holocene coral mound aggradation, and the cessation of mound formation varied between the individual mounds, which was likely the consequence of vertical/lateral changes in water mass structure that placed the mounds near or out of oxygen-depleted waters, respectively.