Mg/Ca ratios in planktonic foraminifera ...
The primary Mg/Ca ratio of foraminiferal shells is a potentially valuable paleoproxy for sea surface temperature (SST) reconstructions. However, the reliable extraction of this ratio from sedimentary calcite assumes that we can overcome artifacts related to foraminiferal ecology and partial dissolut...
| Main Authors: | , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
PANGAEA
2004
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.839006 https://doi.pangaea.de/10.1594/PANGAEA.839006 |
| Summary: | The primary Mg/Ca ratio of foraminiferal shells is a potentially valuable paleoproxy for sea surface temperature (SST) reconstructions. However, the reliable extraction of this ratio from sedimentary calcite assumes that we can overcome artifacts related to foraminiferal ecology and partial dissolution, as well as contamination by secondary calcite and clay. The standard batch method for Mg/Ca analysis involves cracking, sonicating, and rinsing the tests to remove clay, followed by chemical cleaning, and finally acid-digestion and single-point measurement. This laborious procedure often results in substantial loss of sample (typically 30-60%). We find that even the earliest steps of this procedure can fractionate Mg from Ca, thus biasing the result toward a more variable and often anomalously low Mg/Ca ratio. Moreover, the more rigorous the cleaning, the more calcite is lost, and the more likely it becomes that any residual clay that has not been removed by physical cleaning will increase the ratio. These ... : Supplement to: Klinkhammer, Gary P; Haley, Brian A; Mix, Alan C; Benway, Heather M; Cheseby, Maziet (2004): Evaluation of automated flow-through time-resolved analysis of foraminifera for Mg/Ca paleothermometry. Paleoceanography, 19(4), PA4030 ... |
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