Compositional variability in a cold-water scleractinian, Lophelia pertusa : new insights into “vital effects”
Cohen, Anne L.
Gaetani, Glenn A.
Corliss, Bruce H.
George, Robert Y.
MetadataShow full item record
We analyzed Sr/Ca and Mg/Ca ratios in the thecal wall of Lophelia pertusa, a cold-water coral, using SIMS ion microprobe techniques. The wall grows by simultaneous upward extension and outward thickening. Compositional variability displays similar trends along the upward and outward growth axes. Sr/Ca and Mg/Ca ratios oscillate systematically and inversely. The sensitivity of Lophelia Sr/Ca ratios to the annual temperature cycle (−0.18 mmol · mol−1/°C) is twice as strong as that exhibited by tropical reef corals, and four times as strong as the temperature dependence of Sr/Ca ratios of abiogenic aragonites precipitated experimentally from seawater. A comparison of the skeletal composition of Lophelia with results from precipitation calculations carried out using experimentally determined partition coefficients suggests that both temperature-dependent element partitioning and seasonal changes in the mass fraction of aragonite precipitated from the calcifying fluid influence the composition of Lophelia skeleton. Results from calculations that combine these effects reproduce both the exaggerated amplitude of the Sr/Ca and Mg/Ca oscillations and the inverse relationship between Sr/Ca and Mg/Ca ratios.
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 7 (2006): Q12004, doi:10.1029/2006GC001354.
Suggested CitationArticle: Cohen, Anne L., Gaetani, Glenn A., Lundalv, Tomas, Corliss, Bruce H., George, Robert Y., "Compositional variability in a cold-water scleractinian, Lophelia pertusa : new insights into “vital effects”", Geochemistry Geophysics Geosystems 7 (2006): Q12004, DOI:10.1029/2006GC001354, https://hdl.handle.net/1912/1406
Showing items related by title, author, creator and subject.
Constraints on the vital effect in coccolithophore and dinoflagellate calcite by oxygen isotopic modification of seawater Hermoso, Michael; Horner, Tristan J.; Minoletti, Fabrice; Rickaby, Rosalind E. M. (2014-05)In this study, we show that there are independent controls of 18O/16O and 13C/12C fractionation in coccolithophore and dinoflagellate calcite due to the contrasting kinetics of each isotope system. We demonstrate that ...
Spooner, Peter T.; Guo, Weifu; Robinson, Laura F.; Thiagarajan, Nivedita; Hendry, Katharine R.; Rosenheim, Brad E.; Leng, Melanie J. (Elsevier, 2016-02-02)The carbonate clumped isotope thermometer is a promising tool for determining past ocean temperatures. It is based on the temperature dependence of rare isotopes ‘clumping’ into the same carbonate ion group in the carbonate ...