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

Thumbnail Image
Wienberg, Claudia
Titschack, Jürgen
Freiwald, Andre
Frank, Norbert
Lundälv, Tomas
Taviani, Marco
Beuck, Lydia
Schröder-Ritzrau, Andrea
Krengel, Thomas
Hebbeln, Dierk
Alternative Title
Date Created
Related Materials
Replaced By
Lophelia pertusa
Coral mound
Submarine canyon
Uranium-series dating
Mound aggradation rate
Last glacial
Dissolved oxygen concentration
South Atlantic Central Water
Mauritanian margin
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.
© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Quaternary Science Reviews 185 (2018): 135-152, doi:10.1016/j.quascirev.2018.02.012.
Embargo Date
Quaternary Science Reviews 185 (2018): 135-152
Cruise ID
Cruise DOI
Vessel Name
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivatives 4.0 International