(Table 1, 2) Foraminifera biometric data, and boron isotopic composition of Globigerinoides sacculifer of sediments from the Ontong-Java Plateau ...

• Main Authors: Hönisch, Bärbel, Hemming, N Gary
• Format: Dataset
• Language: English
• Published: PANGAEA 2004
• Subjects: Event label; Latitude of event; Longitude of event; Elevation of event; DEPTH, sediment/rock; Depth, top/min; Depth, bottom/max; Size fraction; Mass; δ11B; pH; Magnesium/Calcium ratio; Sea surface temperature, annual mean; Piston corer; Gravity corer; Calculated from d11B; Calculated from Mg/Ca ratios Dekens et al. 2002; RC10; RC14; RC17; V32; V34; Robert Conrad; Vema; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.837805; https://doi.pangaea.de/10.1594/PANGAEA.837805

Sediment samples from the Ontong-Java Plateau in the Pacific and the 90° east ridge in the Indian Ocean were used to investigate whether shell size and early diagenesis affect d11B of the symbiont-bearing planktonic foraminifer Globigerinoides sacculifer. In pristine shells from both study locations we found a systematic increase of d11B and Mg/Ca with shell size. Shells in the sieve size class 515–865 µm revealed d11B values +2.1 to +2.3 per mil higher than shells in the 250–380 µm class. This pattern is most likely due to differences in symbiont photosynthetic activity and its integrated effect on the pH of the foraminiferal microenvironment. We therefore suggest smaller individuals must live at approximately 50–100 m water depth where ambient light levels are lower. Using the empirical calibration curve for d11B in G. sacculifer, only shells larger than 425 µm reflect surface seawater pH. Partial dissolution of shells derived from deeper sediment cores was determined by shell weight analyses and ... : Supplement to: Hönisch, Bärbel; Hemming, N Gary (2004): Ground-truthing the boron isotope-paleo-pH proxy in planktonic foraminifera shells: Partial dissolution and shell size effects. Paleoceanography, 19(4), PA4010 ...