Lorrain Anne, Gillikin D.P., Paulet Y.M., Chauvaud L., Le Mercier A., Navez J., André L. (2005). Strong kinetic effects on Sr/Ca ratios in the calcitic bivalve. Geology, 33 (12), p. 965-968.
Titre du document
Strong kinetic effects on Sr/Ca ratios in the calcitic bivalve
Année de publication
2005
Type de document
Article
Auteurs
Lorrain Anne, Gillikin D.P., Paulet Y.M., Chauvaud L., Le Mercier A., Navez J., André L.
Source
Geology, 2005,
33 (12), p. 965-968
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.
