کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4735351 | 1640836 | 2014 | 6 صفحه PDF | دانلود رایگان |
• Paired benthic Sr/Ca and B/Ca for global core-tops.
• Paired benthic Sr/Ca and B/Ca for 3 down cores.
• Deep water Δ[CO32−] affects benthic foraminiferal Sr/Ca.
• Little change in seawater Sr/Ca during the late Pleistocene.
Changes in the Sr to Ca ratio of sea water have important implications for the interpretation of past climate. It has proven difficult to interpret Sr/Ca of foraminiferal calcite as a measure of seawater Sr/Ca or as reflecting the influence of deep water carbonate ion saturation (Δ[CO32−]) on the incorporation of Sr into benthic foraminiferal carbonate. Here, we address this issue by measurements of paired benthic foraminiferal Sr/Ca and B/Ca (a proxy for deep water Δ[CO32−]) for core-tops from the global ocean and three down cores at different settings during the Last Glacial–interglacial cycle. These new data suggest a significant control of deep water Δ[CO32−] on benthic foraminiferal Sr/Ca, and that down-core shell Sr/Ca variations can be largely accounted for by past deep water Δ[CO32−] changes. We conclude that seawater Sr/Ca has likely remained near-constant on glacial–interglacial timescales during the late Pleistocene, in agreement with model results. With due caution, benthic Sr/Ca may be used as an auxiliary proxy for deep water Δ[CO32−] if seawater Sr/Ca is constant.
Journal: Quaternary Science Reviews - Volume 98, 15 August 2014, Pages 1–6