Mg/Ca and stable oxygen isotope ratios of Uvigerina spp. from the Southern Ocean ...

• Main Authors: Elderfield, Henry, Greaves, Mervyn, Barker, S, Hall, Ian R, Tripati, Aradhna K, Ferretti, Patrizia, Crowhurst, Simon J, Booth, Linda, Daunt, C
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2010
• Subjects: Ocean Drilling Program ODP; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.817532; https://doi.pangaea.de/10.1594/PANGAEA.817532

The sensitivity to temperature of Mg/Ca ratios in the shallow-infaunal benthic foraminifera Uvigerina spp. has been assessed. Core-top calibrations over ~1-20 °C show a range in sensitivity of 0.065-0.084 mmol/mol/°C but few data are available spanning the temperature range anticipated in deep-sea records over glacial-interglacial cycles. In contrast to epibenthic foraminiferal species, carbonate ion saturation appears not to affect Mg/Ca significantly. A method based on estimating the ratio of the temperature sensitivity of foraminiferal Mg/Ca to that of d18Ocalcite shows that sensitivity for Mg/Ca at the high end of the observed core-top range (~0.1 mmol/mol/°C) is required for consistency with LGM-Holocene differences in each property as constrained by independent proxy data. This is supported by a Mg/Ca record for Uvigerina spp. generated for the Southern Ocean over the past 440,000 years from Ocean Drilling Program Site 1123 (Chatham Rise, New Zealand). The record shows variability that correlates with ... : Supplement to: Elderfield, Henry; Greaves, Mervyn; Barker, S; Hall, Ian R; Tripati, Aradhna K; Ferretti, Patrizia; Crowhurst, Simon J; Booth, Linda; Daunt, C (2010): A record of bottom water temperature and seawater d18O for the Southern Ocean over the past 440kyr based on Mg/Ca of benthic foraminiferal Uvigerina spp. Quaternary Science Reviews, 29(1-2), 160-169 ...