%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Coadic, R.
%A Bassinot, F.
%A Douville, E.
%A Michel, E.
%A Dissard, Delphine
%A Greaves, M.
%T A core-top study of dissolution effect on B/Ca in Globigerinoides sacculifer from the tropical Atlantic : potential bias for paleo-reconstruction of seawater carbonate chemistry
%D 2013
%L fdi:010060367
%G ENG
%J Geochemistry Geophysics Geosystems
%@ 1525-2027
%K B/Ca ; planktonic foraminifera ; dissolution ; Atlantic Ocean
%K OCEAN ATLANTIQUE ; ZONE TROPICALE
%M ISI:000319410100019
%N 4
%P 1053-1068
%R 10.1029/2012gc004296
%U https://www.documentation.ird.fr/hor/fdi:010060367
%> https://www.documentation.ird.fr/intranet/publi/2013/06/010060367.pdf
%V 14
%W Horizon (IRD)
%X It has been recently shown that B/Ca in planktonic foraminiferal calcite can be used as a proxy for seawater pH. Based on the study of surface sediments (multi-cores) retrieved along a depth transect on the Sierra Leone Rise (Eastern Equatorial Atlantic), we document the decrease of B/Ca and Mg/Ca of Globigerinoides sacculifer shells with increasing water depth and dissolution. This effect of dissolution on B/Ca may potentially represent a severe bias for paleo-pH reconstructions using this species. Samples of G. sacculifer were analyzed independently at two laboratories for B/Ca and Mg/Ca. Both sets of results show a systematic decrease of B/Ca and Mg/Ca along the depth transect, with an overall loss of similar to 14 mu mol/mol (similar to 15%) for B/Ca and of similar to 0.7mmol/mol (similar to 21%) for Mg/Ca between the shallowest (2640m) and the deepest (4950m) sites. Because of this dissolution effect, surface water pH reconstructed from B/Ca of G. sacculifer decreases by similar to 0.11 units between the shallowest site and the deepest site, a magnitude similar to the expected glacial/interglacial surface water pH changes.
%$ 032 ; 064