Calibration and application of B/Ca, Cd/Ca, and d11B in Neogloboquadrina pachyderma (sinistral) ...

• Main Authors: Yu, Jimin, Thornalley, David J R, Rae, James W B, McCave, I Nick
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2013
• Subjects: Neogloboquadrina pachyderma; North Atlantic; Norwegian Sea; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.821825; https://doi.pangaea.de/10.1594/PANGAEA.821825

The North Atlantic and Norwegian Sea are prominent sinks of atmospheric CO2 today, but their roles in the past remain poorly constrained. In this study, we attempt to use B/Ca and d11B ratios in the planktonic foraminifera Neogloboquadrina pachyderma (sinistral variety) to reconstruct subsurface water pH and pCO2 changes in the polar North Atlantic during the last deglaciation. Comparison of core-top results with nearby hydrographic data shows that B/Ca in N. pachyderma (s) is mainly controlled by seawater [B(OH)4]-/[HCO3]- with a roughly constant partition coefficient (KD =([B/Ca]of CaCO3)/([B(OH)4]-/[HCO3]-)of seawater) of 1.48 ± 0.15 * 10**-3 (2sigma), and d11B in this species is offset below d11B of the borate in seawater by 3.38 ± 0.71 per mil (2sigma). These values represent our best estimates with the sparse available hydrographic data close to our core-tops. More culturing and sediment trap work is needed to improve our understanding of boron incorporation into N. pachyderma (s). Application of a ... : Supplement to: Yu, Jimin; Thornalley, David J R; Rae, James W B; McCave, I Nick (2013): Calibration and application of B/Ca, Cd/Ca, and d11B in Neogloboquadrina pachyderma (sinistral) to constrain CO2 uptake in the subpolar North Atlantic during the last deglaciation. Paleoceanography, 28(2), 237-252 ...