Response of seawater Sr/Ca to changes in shelf-deep sea carbonate deposition during the past 160,000 years
Abstract
On glacial-interglacial time scales, variations of seawater Sr/Ca ratio may reflect changes in terrestrial weathering and shelf-deep sea carbonate deposition and dissolution. Foraminiferal Sr/Ca holds potential for continuous past seawater Sr/Ca reconstructions, but its applicability has been hindered by some secondary processes that influence the incorporation of Sr into foraminiferal calcite. Here, we use global core-top and down core dataset to investigate possible affecting factors on benthic foraminiferal Sr/Ca and the feasibility of using benthic Sr/Ca to extract the seawater Sr/Ca signals. We show that benthic foraminiferal Sr/Ca is influenced by growth pressure and ambient deep water carbonate ion saturation degree. We demonstrate that comparable past seawater Sr/Ca changes during past 160 kyr can be obtained by using benthic foraminiferal Sr/Ca and B/Ca (a proxy for deep water carbonate ion saturation) from different cores in Atlantic and Pacific Oceans. The reconstructed seawater Sr/Ca variations are consistent with past changes in shelf-deep sea carbonate preservation that are associated with sea level variations and global deep oceanic carbonate system changes.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMPP31B1325Y
- Keywords:
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- 4924 PALEOCEANOGRAPHY / Geochemical tracers