Potassium phases and isotopic composition in modern marine biogenic carbonates ...

• Main Authors: Liu, X.-M., Fodrie, F.J., Li, W., Hu, Y.-F., Wang, K., Yoshimura, T.
• Format: Text
• Language: unknown
• Published: Elsevier Ltd 2021
• Subjects: Planktonic foraminifera
• Online Access: https://dx.doi.org/10.17615/kztn-b383; https://cdr.lib.unc.edu/concern/articles/ms35tk33d

To investigate isotope fractionation between biogenic carbonates and modern seawater, we measured K concentration, phase, and isotopic composition in calcified skeletons from a variety of calcifying species. Samples included deep-sea corals, hermatypic corals, bivalves, gastropods, brachiopods, and planktonic foraminifera recovered globally over the past ten years in habitats with temperatures varying from 2 to 29 °C. The δ41K values of the calcified organisms vary significantly, ranging from −0.72 ± 0.11 to 0.94 ± 0.04‰. Deep-sea corals exhibit the largest isotopic variability and the lowest δ41K, ranging from −0.72 ± 0.11 to 0.28 ± 0.09‰. Hermatypic corals display a moderate δ41K, ranging from −0.20 ± 0.07 to 0.37 ± 0.10‰. Bivalves display widely variable δ41K values from 0.04 ± 0.05 to 0.94 ± 0.04‰, including the highest δ41K observed. Gastropods exhibit δ41K values between −0.42 ± 0.06 and −0.12 ± 0.06‰, while brachiopods have δ41K values from −0.30 ± 0.05 to 0.24 ± 0.06‰. Limited foraminifera samples (n ...