Potential influence of the chemical composition of water on the stable oxygen isotope composition of continental ostracods

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Etat: Public
Version: de l'auteur
ID Serval
serval:BIB_ABB0C4D446DE
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Potential influence of the chemical composition of water on the stable oxygen isotope composition of continental ostracods
Périodique
Journal of Paleolimnolgy
Auteur(s)
Decrouy L., Vennemann T.W.
ISSN-L
1573-0417
Statut éditorial
Publié
Date de publication
2013
Peer-reviewed
Oui
Volume
50
Pages
577-582
Langue
anglais
Résumé
Many studies in continental areas have successfully used the oxygen isotope composition of fossil ostracod valves to reconstruct past hydrological conditions associated with large changes in climate. Yet, ostracods are known to crystallise their valves out of isotopic equilibrium for oxygen and they generally have higher 18O contents compared to inorganic calcite grown at equilibrium under the same condi- tions. A review of vital offsets determined for continental ostracods indicates that vital offsets might change from site to site, questioning a potential influence of environmental conditions on oxygen isotope fractionation in ostracods. Results from the literature suggest that pH has no influence on ostracod vital offset. A re-evaluation of results from Li and Liu (J Paleolimnol 43:111-120, 2010) suggests that salin- ity may influence oxygen isotope fractionation in ostracods, with lower vital offsets for higher salinities. Such a relationship was also observed for the vital offsets determined by Chivas et al. (The ostracoda- applications in quaternary research. American Geo- physical Union, Washington, DC, 2002). Yet, when results of all studies are compiled, the correlation between vital offsets and salinity is low while the correlation between vital offsets and host water Mg/Ca
is higher, suggesting that ionic composition of water and/or relative abundance of major ions may also control oxygen isotope fractionation in ostracods. Lack of data on host water ionic composition for the different studies precludes more detailed examination at this stage. Further studies such as natural or laboratory cultures done under strictly controlled conditions are needed to better understand the potential influence of varying environmental condi- tions on oxygen isotope compositions of ostracod valves.
Création de la notice
14/12/2012 12:33
Dernière modification de la notice
20/08/2019 15:15
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