A strong temperature effect on U/Ca in planktonic foraminiferal carbonates
Three planktonic foraminiferal species Globigerina bulloides, Neogloboquadrina pachyderma (d), and Globorotalia inflata collected from core-tops spanning 35° to 65°N in the North Atlantic were used for U/Ca and Mg/Ca and foraminiferal shell weight analyses. Except for U/Ca in G. bulloides calcified...
| Published in: | Geochimica et Cosmochimica Acta |
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| Main Authors: | , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Elsevier
2008
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| Subjects: | |
| Online Access: | http://eprints.esc.cam.ac.uk/824/ http://eprints.esc.cam.ac.uk/824/1/Yu_Elderfield_Booth_GeoChim_Cosmo_Acta_72_2008.pdf http://www.sciencedirect.com/science/article/B6V66-4T2S8V1-2/2/9ab52ff2ead2ff33c0fd3510b8d97767 https://doi.org/10.1016/j.gca.2008.07.011 |
| Summary: | Three planktonic foraminiferal species Globigerina bulloides, Neogloboquadrina pachyderma (d), and Globorotalia inflata collected from core-tops spanning 35° to 65°N in the North Atlantic were used for U/Ca and Mg/Ca and foraminiferal shell weight analyses. Except for U/Ca in G. bulloides calcified under warm conditions (>not, vert, similar13 °C), U/Ca ratios in all three studied species increase with decreasing latitude and show strong positive correlations with Mg/Ca ratios. A dissolution effect on planktonic U/Ca is suggested by decreased shell weight and U/Ca and Mg/Ca ratios for shells from very deep water depth (>4.4 km) along the latitudinal transect. G. bulloides from down core samples in the North Atlantic show low U/Ca ratios during the last glacial and high ratios during the Holocene, similar to the Mg/Ca evolution trend. In general, our data indicate that the U incorporation into planktonic foraminiferal carbonates is strongly influenced by calcification temperature, although U/Ca in G. bulloides may be affected by seawater carbonate ion concentration under warm conditions and/or other factors. |
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