The giant Mauritanian cold-water coral mound province

• Verfasst von: Wienberg, Claudia [VerfasserIn]
• Verfasst von: Frank, Norbert [VerfasserIn]
• Verfasst von: Schröder-Ritzrau, Andrea [VerfasserIn]
• Verfasst von: Krengel, Thomas [VerfasserIn]
• Titel: The giant Mauritanian cold-water coral mound province
• Titelzusatz: Oxygen control on coral mound formation
• Verf.angabe: Claudia Wienberg, Jürgen Titschack, André Freiwald, Norbert Frank, Tomas Lundälv, Marco Taviani, Lydia Beuck, Andrea Schröder-Ritzrau, Thomas Krengel, Dierk Hebbeln
• E-Jahr: 2018
• Jahr: 20 February 2018
• Umfang: 18 S.
• Fussnoten: Gesehen am 17.03.2020
• Titel Quelle: Enthalten in: Quaternary science reviews
• Ort Quelle: Amsterdam [u.a.] : Elsevier, 1982
• Jahr Quelle: 2018
• Band/Heft Quelle: 185(2018), Seite 135-152
• ISSN Quelle: 0277-3791
• DOI: doi:10.1016/j.quascirev.2018.02.012
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Coral mound
• Sach-SW: Dissolved oxygen concentration
• Sach-SW: Last glacial
• Sach-SW: Mauritanian margin
• Sach-SW: Mound aggradation rate
• Sach-SW: South Atlantic Central Water
• Sach-SW: Submarine canyon
• Sach-SW: Uranium-series dating
• K10plus-PPN: 1692685287

Abstract

The largest coherent cold-water coral (CWC) mound province in the Atlantic Ocean exists along the Mauritanian margin, where up to 100m high mounds extend over a distance of ∼400km, arranged in two slope-parallel chains in 400-550m 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 16cmkyr−1. Most prolific periods for CWC growth are identified for the last glacial and deglaciation, resulting in enhanced mound aggradation (>1000cmkyr−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.