Delta 13C measured on alkenones of surface sediment samples GeoB1008-6 to GeoB3603-1 from the South Atlantic ...

• Main Authors: Benthien, Albert, Andersen, Nils, Schulte, Sonja, Müller, Peter J, Schneider, Ralph R, Wefer, Gerold
• Format: Dataset
• Language: English
• Published: PANGAEA 2002
• Subjects: Event label; Latitude of event; Longitude of event; Elevation of event; DEPTH, sediment/rock; Alkenone, unsaturation index UK37; Sea surface temperature, annual mean; Alkenone C372, δ13C; Alkenone, Ep; Carbon dioxide, total; -; Phosphate; Nitrate; Giant box corer; Gravity corer Kiel type; MultiCorer; Calculated; Mass spectrometer Finnigan MAT 252; Gas chromatography; M6/6; M9/4; M12/1; M16/1; M16/2; M20/2; SO84; M23/2; M23/3; JOPSII-6; M34/1; Meteor 1986; Sonne; Victor Hensen; Geosciences, University of Bremen GeoB; South Atlantic Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.63632; https://doi.pangaea.de/10.1594/PANGAEA.63632

We have analyzed the stable carbon isotopic composition of the diunsaturated C37 alkenone in 29 surface sediments from the equatorial and South Atlantic Ocean. Our study area covers different oceanographic settings, including sediments from the major upwelling regions off South Africa, the equatorial upwelling, and the oligotrophic western South Atlantic. In order to examine the environmental influences on the sedimentary record the alkenone-based carbon isotopic fractionation (Ep) values were correlated with the overlying surface water concentrations of aqueous CO2 ([CO2(aq)]), phosphate, and nitrate. We found Ep positively correlated with 1/[CO2(aq)] and negatively correlated with [PO43-] and [NO3-]. However, the relationship between Ep and 1/[CO2(aq)] is opposite of what is expected from a [CO2(aq)] controlled, diffusive uptake model. Instead, our findings support the theory of Bidigare et al. (1997, doi:10.1029/96GB03939) that the isotopic fractionation in haptophytes is related to nutrient-limited ... : Supplement to: Benthien, Albert; Andersen, Nils; Schulte, Sonja; Müller, Peter J; Schneider, Ralph R; Wefer, Gerold (2002): Carbon isotopic composition of the C37:2 alkenone in core-top sediments of the South Atlantic Ocean: Effects of CO2 and nutrient concentrations. Global Biogeochemical Cycles, 16(1), 1012 ...