Removal of contamination influences on geochemical analysis results of planktonic foraminifera shells collected from marine sediment core and paleoclimatological implication.

Abstract

Planktonic foraminifera shells preserved in marine sediment are excellent archives to record long-term marine environment of the past. For instance, Mg/Ca ratio of the shell records sea surface temperature; boron isotope ratio (δ¹¹B) records seawater pH, leading to wide application in paleoclimatology. However, these proxies are easily contaminated by clay which is a major constituent of marine sediment, thus accurate environmental reconstruction requires intense shell cleaning and data-screening of problematic data. Here we report the results of various geochemical analyses (B/Ca、δ¹¹B、δ¹³C、δ¹⁸O、Mg/Ca、Al/Ca、Sr/Ca、^87/86Sr、Ba/Ca) on planktonic foraminifera Orblina universa (size fraction: 500–850 μm) that were collected from marine sediment core recovered from the West Indian Ocean under the International Ocean Discovery Project Expedition 361 (Site U1476).