Article ID Journal Published Year Pages File Type
4678537 Earth and Planetary Science Letters 2010 7 Pages PDF
Abstract

Reliable reconstructions of deep ocean carbonate ion concentration, [CO32−], and pH are crucial to understand mechanisms responsible for the past atmospheric CO2 variations observed in ice cores. However, it is challenging to reconstruct past deep water [CO32−] and pH and literature results from different proxies conflict, warranting careful investigations on possible reasons for the existing inconsistencies. Here, we present the first down core B/Ca and δ11B records measured in an epifaunal benthic foraminifer Cibicidoides wuellerstorfi from the Caribbean Sea during the last 160 kyr. The two proxies yield quantitatively comparable deep water [CO32−] and pH results, showing high values during glacials relative to inter-glacials (differences in [CO32−] and pH are ∼ 35 μmol/kg and ∼ 0.15, respectively), consistent with past ocean circulation changes in the Caribbean Sea. Our data provide convincing evidence that both proxies serve as faithful proxies to estimate deep ocean [CO32−] and pH, despite our incomplete understanding of boron incorporation into foraminiferal carbonates.

Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Earth and Planetary Sciences (General)
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