%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture non répertoriées par l'AERES
%A Lorrain, Anne
%A Gillikin, D.P.
%A Paulet, Y.M.
%A Chauvaud, L.
%A Le Mercier, A.
%A Navez, J.
%A André, L.
%T Strong kinetic effects on Sr/Ca ratios in the calcitic bivalve
%D 2005
%L PAR00007493
%G ENG
%J Geology
%M HAL:hal-00452403
%N 12
%P 965-968
%U https://www.documentation.ird.fr/hor/PAR00007493
%V 33
%W Horizon (IRD)
%X Although Sr/Ca ratios in abiogenic calcite are strongly controlled by precipitation rates, such a kinetic effect has never been demonstrated in calcitic bivalve shells. Therefore, we report Sr/Ca ratios together with daily growth rates in the calcitic shells of 4 individuals of the bivalve Pecten maximus (age class I). Ratios of Sr/Ca were found to be variable among individuals that grew at the same location, illustrating that vital effects dominate over environmental controls. Although daily growth rate was correlated with shell Sr/Ca ratios, it explained only half of the Sr/Ca variations. However, daily shell surface area increment, an estimation of the total quantity of carbonate precipitated for a given time, explained 74% of the Sr/Ca variability in the shells of P. maximus. This proves, for the first time in a calcitic bivalve, that shell Sr/Ca partitioning is mainly controlled by kinetic effects. The Sr/Ca ratio should therefore be tested as a potential proxy of calcification rate in modern or fossil calcitic biocarbonates.
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