Planktonic foraminiferal Cd/Ca ratios, supplement to: Rickaby, Rosalind E M; Elderfield, Henry (1999): Planktonic foraminiferal Cd/Ca: Paleonutrients or paleotemperature? Paleoceanography, 14(3), 293-303
Records of Cd/Ca in planktonic foraminiferal calcite of Globigerinoides bulloides in cores from the Subantarctic region of the Southern Ocean show large glacial-interglacial variations with lower Cd/Ca (by 0.06-0.10 µmol/mol) at glacial times. Interpretation of these records in terms of lower dissol...
| Main Authors: | , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
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PANGAEA - Data Publisher for Earth & Environmental Science
1999
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.856843 https://doi.pangaea.de/10.1594/PANGAEA.856843 |
| Summary: | Records of Cd/Ca in planktonic foraminiferal calcite of Globigerinoides bulloides in cores from the Subantarctic region of the Southern Ocean show large glacial-interglacial variations with lower Cd/Ca (by 0.06-0.10 µmol/mol) at glacial times. Interpretation of these records in terms of lower dissolved phosphate and inferred higher glacial nutrient utilization has significant implications for glacial atmospheric carbon dioxide (pCO2) draw-down. However, box core-top data for G. bulloides in the North Atlantic suggest that the incorporation of Cd into planktonic foraminifera relative to seawater (DCd) is temperature sensitive (DCd=0.637 exp 0.15T). When the Subantarctic planktonic Cd/Ca records are corrected for this temperature dependence, they show little or no glacial-interglacial diferences. If, as seems likely, this observation can be interpreted to indicate a minimal change (< 0.5 µmol/kg) in surface water phosphate concentrations, then the explanation for lowered glacial pCO2 must be looked for elsewhere. |
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