Geochemistry of planktonic foraminifera from DSDP sites in the Atlantic and Pacific Ocean ...
The lithium content of planktonic foraminiferal calcite has been determined to evaluate temporal variability of seawater Li concentrations over the past 116 m.y. Mean foraminiferal calcite lithium/calcium in each time interval is no more than 16% greater nor 25% less than the mean Li/Ca of all sampl...
| Main Authors: | , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
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PANGAEA
1986
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.715079 https://doi.pangaea.de/10.1594/PANGAEA.715079 |
| Summary: | The lithium content of planktonic foraminiferal calcite has been determined to evaluate temporal variability of seawater Li concentrations over the past 116 m.y. Mean foraminiferal calcite lithium/calcium in each time interval is no more than 16% greater nor 25% less than the mean Li/Ca of all samples. Li/Ca minima are observed for samples from 50-60 m.y. and 80-90 m.y., with Li/Ca about 25% lower than in adjacent time intervals. At no time during the past 40 m.y does mean Li/Ca appear to be higher than that at present. Subject to the limitations imposed by sample coverage and diagenesis, a similar conclusion holds for the past 116 m.y. Coupled with an oceanic mass balance model for Li, these data suggest that: (1) oceanic Li concentrations and, therefore, high-temperature hydrothermal circulation fluxes during the past 40 m.y. (and perhaps the past 100 m.y.) have not been more than perhaps 30-40% greater than at present for intervals any longer than a million years at most, and (2) these fluxes were not a ... : Supplement to: Delaney, Margaret Lois; Boyle, Edward A (1986): Lithium in foraminiferal shells: implications for high-temperature hydrothermal circulation fluxes and oceanic crustal generation rates. Earth and Planetary Science Letters, 80(1-2), 91-105 ... |
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