Environmental boundary conditions of cold-water coral mound growth over the last 3 million years in the Porcupine Seabight, Northeast Atlantic

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doi: 10.1016/j.dsr2.2013.06.009
Author(s): Raddatz, Jacek; Rüggeberg, Andres; Liebetrau, Volker; Foubert, Anneleen; Hathorne, E. C.; Fietzke, Jan; Eisenhauer, Anton; Dullo, Wolf-Christian
Author Affiliation(s): Primary:
GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Kiel, Germany
Volume Title: Biology and geology of deep-sea coral ecosystems; proceedings of the Fifth international symposium on Deep-sea corals
Volume Author(s): Mienis, Furu, editor; Duineveld, Gerard; Lavaleye, Marc; van Weering, Tjeerd
Source: Deep-Sea Research. Part II: Topical Studies in Oceanography, Vol.99, p.227-236; Fifth international symposium on Deep-sea corals, Amsterdam, Netherlands, April 1-6, 2012, edited by Furu Mienis, Gerard Duineveld, Marc Lavaleye and Tjeerd van Weering. Publisher: Elsevier, Oxford, International. ISSN: 0967-0645
Note: In English. 87 refs.; illus., incl. sketch map
Summary: IODP Expedition 307 made it for the first time possible to investigate the entire body of a cold-water coral carbonate mound. Here we provide new insights into the long-term history of Challenger Mound on the European continental margin off Ireland. This study is based on age determinations (230Th/U, 87Sr/86Sr) and geochemical signals (Mg/Li and Ba/Ca) measured in the scleractinian cold-water coral Lophelia pertusa from IODP Site 1317 in the Porcupine Seabight. The paleoceanographic reconstructions reveal that coral growth in the Porcupine Seabight was restricted to specific oceanographic conditions such as enhanced export of primary production and Bottom-Water Temperatures (BWT) between ≈8 and 10°C, related to the water mass stratification of the Mediterranean Outflow Water (MOW) and Eastern North Atlantic Water (ENAW). The geochemical signals from the coral skeletons can be explained by the close interaction between cold-water coral growth, sea-surface productivity and the surrounding water masses - the boundary layer between MOW and ENAW. Enhanced sea-surface productivity and the build-up of a stable water mass stratification between ENAW and MOW caused enhanced nutrient supply at intermediate water depths and facilitated a steady mound growth between ≈3.0 and 2.1 Ma. With the decrease in sea-surface productivity and related reduced export productivity the food supply was insufficient for rapid coral mound growth between ≈1.7 and 1 Ma. During the late Pleistocene (over the last ≈0.5 Myr) mound growth was restricted to interglacial periods. During glacials the water mass boundary between ENAW/MOW probably was below the mound summit and hence food supply was not sufficient for corals to grow. Abstract Copyright (2014) Elsevier, B.V.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Absolute age; Alkali metals; Alkaline earth metals; Anthozoa; Atlantic Ocean; Ba/Ca; Barium; Calcium; Cenozoic; Challenger Mound; Chemostratigraphy; Cnidaria; Cold-water environment; Deep-sea environment; Expedition 307; Geochemical methods; IODP Site U1317; Integrated Ocean Drilling Program; Invertebrata; Isotope ratios; Isotopes; Lithium; Magnesium; Marine environment; Metals; Mg/Li; Mounds; Neogene; North Atlantic; Northeast Atlantic; Paleo-oceanography; Pliocene; Porcupine Seabight; Quaternary; Reconstruction; Reefs; Scleractinia; Skeletons; Sr-87/Sr-86; Stable isotopes; Strontium; Tertiary; Th/U; Zoantharia
Coordinates: N512300 N512300 W0114300 W0114300
Record ID: 2014093850
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands